Welcome to the NPTEL lecture on video course geotechnical earthquake engineering. We were going through module number 9 of this course that is seismic analysis and design of various geotechnical structures. So, let us have a quick recap what we have learned in our previous lecture. We started with the subtopic within this module that is seismic design of retaining wall. We have mentioned that what are the various state of earth pressures acting on the retaining wall based on the movement of the wall. Same remains in the case of earthquake condition also. There are various examples worldwide the failures of retaining wall due to the additional destabilizing earthquake forces which comes on the retaining wall during the earthquake process. So, unless we estimate this extra or additional destabilizing earthquake force on the retaining wall and consider those for the design of retaining wall then failure cannot be avoided. So, for the seismic analysis and design of retaining wall we need to compute the combined earth pressure that is static plus seismic whether it is a active state or passive state of earth pressure and to do that we basically follow two different types of approach. One approach is called force based approach where we compute the earth pressure using the force equilibrium etcetera. Another is displacement based approach where in addition to the computation of seismic earth pressure we also compute how much amount of displacement of the wall is going to take place which is necessary for the performance based design. Then we had introduced what is the pseudo static method which was originally proposed by Terzaghi in the year 1950 and this is nothing but a coefficient which is multiplied with respect to the failure soil mass which will give the seismic inertia force. So, this is the additional destabilizing force as we can see from the D'Alembert's principle of mechanics. If there is an acceleration A the corresponding static inertia force or equivalent static inertia force will be A w by g where this small g is acceleration due to gravity. So, for this this book of Tuhata can be referred to for the details. Then we have seen what is the conventional seismic design of retaining wall which is nothing but the pseudo static approach as proposed by Mononobe and Matsu in 1929 and by Okabe in 1926 which is combinedly and commonly known as Mononobe Okabe method of 1929 which is the pioneering work for computation of seismic earth pressure on retaining wall. So, this is how the Mononobe Okabe method was proposed which is nothing but an extension of Coulomb's static earth pressure theory. So, in Coulomb's static earth pressure theory as we all know we have already seen this one for suppose for the active state of earth pressure the wall tends to move in this direction for an assumed failure plane with respect to a failure angle like rho over here. We know what is the value of this failure mass or weight w in this vector totally is known because it is magnitude and direction is known. Then we have the active earth pressure P a acting at an angle delta where delta is the wall friction angle and this soil reaction R which acts at an angle phi which is the soil friction angle. Now, these three forces should be concurrent forces to maintain equilibrium and if we draw the force polygon by knowing the line of action of this P a and R we will get the force polygon or closed triangle like this. So, this is w which is completely known now by drawing this line and line here wherever the intersect we will get the value of P a over here value of soil reaction R over here. So, for design what we do for conventional static analysis of Coulomb earth pressure theory we maximize this value of P a to get the design value of active earth pressure by changing this angle failure angle rho. So, that this maximum value of P a is obtained. Now, in the mononope wocabe method they added this values of K h w in both the direction for analysis and this K v w in both the directions and the critical direction whichever gives the maximum value of P a e that needs to be estimated under the earthquake condition or using the pseudo static approach. Also for the passive state so, this is for the active state as you can see over here. So, similarly for the passive state also we have seen that this is the Coulomb's passive earth pressure closed triangle or force polygon where w is again known R and P p their angle their directions are known, but magnitude was not known, but using this force polygon that is all the forces are concurrent we can get their magnitude also this is P p passive earth pressure this is the soil resistance and in addition to that this K h w and K v w has been introduced by mononope wocabe for pseudo static analysis, but limitations of this pseudo static approach we had already learnt in our previous lecture that is first of all this value of K h and K v what should be used for design is not clear. Also soil amplification we cannot consider in this pseudo static approach variation of the seismic acceleration with respect to depth cannot be considered in this pseudo static approach and effect of the dynamic soil properties are not possible to consider that means suppose if you are designing a retaining wall in a soft soil may be the loose sand and another retaining wall in the dense sand for both of them as far as the chosen soil properties are considered you can only take care of the static soil property that is phi value and wall friction value etcetera, but you cannot take any dynamic soil property which is also important factor as far as earthquake engineering is concerned as we have already learnt. So, what are the various available literature in the literature for the seismic earth pressure estimation using pseudo static approach and the recent pseudo dynamic approach there are many researchers who have proposed this work starting from mononope wocabe as I said 1926 and 29 then Madhavan, Kamesharao 1969, Richard and Elms 1979, Saran and Prakash 1979, Prakash 1981, Nadim and Whitman in 1983, Steedman and Zeng in 1990, Ebeling and Morrison 1992, Das 1993, Kramer 1996, Kumar 2002, Chaudhary and Subbarov 2005, Chaudhary and Nimbalka 2005 and many other researchers. So, we will talk about some of the recent research work on this seismic earth pressure not this pioneering or the older or former research work because that mostly closely relates to the mononope wocabe method the alteration of that method. So, we will more focus on the recent development of this seismic earth pressure theories for both active as well as passive condition. Now when we talk about the pseudo static method of approach the mononope wocabe method was force based method because in that case as we have already seen we consider only the force equilibrium and we estimate the value of P a e or P p e. But as I have mentioned for performance based design we need to look into the displacement based approach where we talk about the displacement of the wall also. So, to the pioneering work in the displacement based approach was proposed by Richard and Ems in 1979 this is the detail of the paper one can easily get you can see the details of the paper Richard and Ems 1979 seismic behavior of gravity retaining walls it was published in journal of geotechnical engineering of ASC volume 105 issue 4 page number is given over here. So, what it proposed in addition to the computation of this active earth pressure P a e under earthquake condition using the same pseudo static approach. But additionally it mentioned that it can be checked with respect to the permissible displacement of the wall and how to estimate the permissible displacement you can see this is the seismic active earth pressure can you see in the picture over here it is point of action also is considered like this. Now, within the wall wall is also subjected to if wall is having weight of w w then wall is subjected to seismic inertia force of k h w w and k v w w. So, these are the wall inertia forces including the wall self weight and for the stability this wall can either move in the sliding pattern that is it can translate or it can rotate or it can have a combination of these two. So, these are nothing but the displacements or movement sliding or the rotational. So, Richard and Ems proposed the sliding mode of movement that is for the amount of movement how to estimate it this is the force of resistance this is the normal reaction this is the reaction of or resultant of this f and n acting at an angle phi b where phi b is nothing but the angle of friction between this base of the wall and the foundation soil. So, displacement should be calculated using the formula and should be checked against the allowable displacement. So, the permissible displacement can be computed with respect to 0.087 v max square a max cube by a y to the power 4 where v max is the peak ground velocity a max is the peak ground acceleration and what is a y a y is known as yield acceleration for the wall backfill system. What is yield acceleration? Let me describe it what is the definition of yield acceleration yield acceleration is that acceleration when the factor of safety with respect to sliding of this wall will be equals to 1. So, a y refers to that seismic acceleration which beyond which if the acceleration increases then wall starts moving because then factor of safety with respect to sliding will be less than 1 right. So, a y gives us the that limiting value or that threshold value of acceleration at which factor of safety is equals to 1 that is known as yield acceleration. So, how to estimate that obviously as we know this will be nothing but factor of safety against sliding will be the stabilizing force with respect to sliding divided by the disturbing force. Disturbing force we know it is the horizontal component of this seismic active earth pressure and this seismic inertia of the wall which are causing the disturbance of the wall or tends the wall to move in this direction whereas what are the stabilizing forces this frictional force which can be computed as tan of this angle times the normal reaction. What will be the normal reaction that is nothing but if you do the vertical equilibrium this normal reaction is nothing but equals to weight of the wall and the vertical component of the pressure which helps to find it out. So, it has to be done algebraically to find out the normal reaction and normal reaction times tan of this base angle base friction angle will give you the stabilizing force right. So, that stabilizing force divided by the disturbing force will give you factor of safety against sliding that has to be equated with respect to 1 to get the a y value. Once you get the a y value you can always get the permissible displacement. Now, this is the permissible displacement under a particular given value of a max and corresponding value of v max. Now, if your allowable displacement for a wall if it is specified at a project then automatically you should keep your permissible displacement within the range of your allowable displacement and accordingly you can design the wall section. So, that your a y value etcetera comes accordingly. So, that this permissible value of displacement is within the allowable range clear. So, that these are the basic steps of the displacement based approach of the pseudo static method of design. Now, for pseudo static method further the method was extended by other researchers as I said the recent research work I will describe Choudhury and Subbarao in 2002 gave the design chart for the estimation of seismic passive earth pressure coefficient for negative wall friction case. What is negative wall friction case? Let me describe it little bit. So, when we are talking about passive condition of earth pressure as we have already mentioned for passive state of earth pressure on a rigid retaining wall. If we have ground like this and this is the failure plane we have weight of this for passive condition this is the R. Now, if we have seen already the P P value will be acting over here at an angle delta. This passive earth pressure when wall tends to move in this direction is nothing but called positive delta, but there can be few cases where this passive force may act in this direction also which is called as negative delta. This passive earth pressure is nothing but an application of this where we can apply this passive earth pressure not only for the design of retaining wall. This passive earth pressure we can apply for bearing capacity of foundation as well as anchor uplift capacity. How? Let me describe you when we are talking about some footing shallow footing problem like this which is let us say embedded at a depth shallow depth like this. As we all know let us consider the Terzaghi's bearing capacity failure theory which is all known to all of us from the basic geotechnical engineering course. So, this is the Terzaghi's theory which says we have one zone over here which is known as this angle is phi for static case. This is a zone one which is named as active zone. This is zone two which is log spiral zone and this zone three is rank in passive zone. This is log spiral zone and it is asymmetrical under the static condition. Now, if we consider this line let us look at here this line as a imaginary wall what we can say there it will be passive earth pressure acting at an angle delta with respect to normal to this. Why it is a passive earth pressure? First of all when we are talking about this imaginary wall let us see how the displacement is occurring when the load is acting on the footing from the column etcetera. This soil tries to punch inside and go inside. So, this surrounding soil moves this direction this wall tends to move in this direction towards the backfill side that is why it is a passive state of earth pressure clear. Why it is a passive state of earth pressure? Because this wall tends to move in this direction. Now, why it is in this direction of passive earth pressure? Because it is an acting at an angle delta and considering this composite failure surface that is log spiral followed by a rank in passive zone. We get the passive earth pressure acting in this direction which will balance this w and this outside load. So, basically 2 pp equals to q plus w this is the application of positive wall friction angle of passive earth pressure where what is the movement of the wall with respect to surrounding soil? Wall moves down this wall moves down compared to surrounding soil surrounding soil moves up that is why it is named as positive wall friction angle. What is negative wall friction angle? So, for positive wall friction angle what happens? Wall moves down surrounding soil moves up that is the relative movement between wall and soil for positive wall friction. For negative wall friction it is reverse in the sense wall moves up and this soil goes down. So, where is the application of that? Its application comes in the form of anchor uplift capacity where we can get that. Let us say this is an anchor plate which is being pulled by this force this is the ground surface we all know from our static theory. So, this will be failure surface let us say. So, if we consider this as imaginary wall imaginary retaining wall what is happening? First of all if we take this normal on this side there will be force in this direction which we will call as negative delta p p. Why? Why it is passive earth pressure? Because this imaginary wall again it tends to move in this direction when we are pulling out the anchor when we are taking out the anchor like this. Obviously, this wall tends to move in this direction towards the backfill. So, when we talk about this backfill and this imaginary wall it is nothing, but passive state and why we call it as negative delta? Because in this case this wall moves up and this surrounding soil moves down because this entire central area goes up this goes down clear. So, that is referred as negative wall friction angle case. So, passive earth pressure is very much utilized in geotechnical engineering for anchor uplift capacity whether it is a negative wall friction angle case or for shallow foundation bearing capacity theory if it is a positive wall friction. So, that is what in this paper if we look here for this negative wall friction means where this anchor uplift capacity is the application as it is mentioned. We had obtained the design chart for this passive earth pressure coefficient under the dynamic condition with respect to the unit weight component. There are two three components if you consider the generalized C phi soil where cohesion is also present and friction angle is also present including the surcharge on the ground surface. So, then the total seismic passive resistance can be computed using this expression and each of the this k values are nothing, but seismic passive earth pressure coefficient with respect to cohesion with respect to surcharge and with respect to unit weight. This chart gives the how this unit weight related seismic passive earth pressure varies with respect to pseudo static seismic acceleration k h and k v. You can see k v is 0, k v is half of k h and k v is 1 k h because these are typical ranges of k v and as per AASHTO code it says about two-third of k h should be considered for design as k v value. So, for different values of phi that is soil friction angle this design chart gives for a particular wall inclination ground inclination and for a particular ratio of wall friction angle to soil friction angle and that value should be negative as I have already mentioned this is the case for negative wall friction angle. So, the details about this concept can be obtained using pseudo static method in this journal paper by this is my work Choudhury with my supervisor Professor Subarao in 2002 seismic passive earth resistance for negative wall friction which is published in Canadian geotechnical journal volume 39 issue 5 these are the page numbers. Now, further that pseudo static method again applied to compute the point of application of the earth pressure because earlier if you remember when we talked about this earth pressure. Let us look at where this total value of p a or in dynamic condition p a e where they will act is not known. Mononobe Okabe had considered that let us say this will act at as one-third of height of the wall from the base as they considered it is a hydrostatic distribution of the pressure. So, they considered one-third from the base, but there is no logical explanation why it should be at one-third it was based on an assumption like is coulombic theory also we assume that it is hydrostatic pressure, but in static condition we know yes it is a hydrostatic condition. So, it has to be one-third from the base, but in this case it is dynamic case also why it should be at one-third that should be questioned. So, it need to be obtained where this point of application of this design value of this p a is acting because for design of this retaining wall we should know not only the value of this force, this value of force will give us to design the section, but to put the reinforcement in the wall suppose if you are going to use the reinforced concrete wall as a retaining wall you need to know how much reinforcement at different levels you are going to put and for that you should know what is the distribution or exact point of application of this p a so that accordingly you can place your reinforcement. So, point of application is also should be known and that also takes care of your sliding analysis, rotation analysis everything because every case the point of application is an important parameter. So, to find out that what has been done you can see in this paper Choudhury et al 2005 we worked this comprehensive review of different methods how to estimate the seismic passive earth pressure using pseudo static approach and their point of application. This is published in the journal current science in 2004 you can see these are the details Choudhury, Sitaram and Subbarao 2004 with my teachers professor Sitaram and professor Subbarao this paper was published in the journal current science volume 87 issue 10 these are the page numbers. So, what we did we considered an inclined rigid wall section. So, this is the face of the wall this is the ground surface horizontal ground surface for passive state of earth pressure we determined that is why displacement of the wall is showing in this direction. The entire failure zone which has to be optimized of course with respect to this failure angle as I have already mentioned, but in addition to that the entire zone we have not taken as a single mass, but we have divided it into number of small horizontal slices infinitesimal small slices like this a b c d of thickness d y at a depth of y from the ground surface. So, for each of this slices we considered what are the forces acting static force as well as the seismic pseudo static forces then considering equilibrium of each slices and doing the analysis and integrating over the entire height we got the expression for point of application for the seismic passive resistance in this form where omega is the excitation frequency v s v p r the shear and primary wave velocities etcetera can be used for estimation of this point of application. Then seismic passive resistance by pseudo static method for a generalized C phi soil was also estimated by us considering composite failure surface why composite we have taken because in the passive state of earth pressure we know planar failure surface seriously overestimates the value for passive case we should get the minimum value, but planar failure surface when the wall friction angle that is delta value exceeds phi by 3 that is one third of the soil friction angle in that case we should not consider for passive case it is always non-linear or curved failure surface. It is no longer a planar failure surface that Tarzaghi himself has mentioned way back in 1943 the same is true for the seismic condition also.  So, that combination has been taken for this retaining wall phase is a b of height h for the passive earth pressure condition considering the surcharge on the ground uniform surcharge small q this is a c phi soil. So, there are three components of passive earth pressure one is with respect to gamma that is unit weight component which acts at one third from the base then cohesion component p p c d which acts at mid height of the wall and p p q d is the surcharge component of passive earth pressure which also acts at the mid height of the wall. Then summing them up we will get the total seismic passive resistance the details about this study is available in this journal paper seismic passive earth pressure in soil journal of geotechnical and geo environmental engineering of a c published in 2005 volume 131 issue 1 these are the page numbers. So, what we had proposed in this case finally we gave the design chart that is for how to use this coefficient of passive earth pressure for different input values of k h and k v. So, how people can use it very easily for a particular seismic zone in India or if anywhere in the world they should get what should be the input parameter of design value of k h may be based on design basis earthquake or something like that to estimate k h value and k v value based on that input k v and k h value at the site what is the value of phi friction angle of the soil you can go to this chart get the value of this seismic passive earth pressure coefficient and directly using the formula as I had already mentioned this formula you can get the passive earth pressure. So, that way the design of the wall you can do once you know the passive earth pressure they are total value and also their point of application for further design. Now, in pseudo static method other researchers also work as I have already mentioned only the very recent research works I am showing you here like Shukla et al in 2009 they described the derivation of an analytical expression for the estimation of total active force that is static plus seismic active force on a retaining wall with a backfill of c phi that is both cohesion and frictional soil considering both the horizontal and vertical seismic acceleration. So, what is the expression for the computation of total active earth pressure under seismic condition is this one. So, this active earth pressure coefficient k a e gamma is with respect to the unit weight component of the soil whereas, k a e c is the coefficient of active earth pressure with respect to cohesion component and their expressions for k a e gamma and k a e c is given by these expressions where tan theta in this expression this theta tan theta is nothing but k h by 1 minus k v like for mononobe okabe also this is the same expression and alpha c is the critical failure angle with phi is the frictional angle of the soil. So, this is the details about the paper that is Shukla Gupta and Shibakugan this was published in journal of geotechnical and geo environmental engineering of a s c this volume this page numbers in 2009. Now, let us see what are the advantages and disadvantages of this pseudo static method when we are doing the analysis for retaining wall what are the major limitations first let us look at that like representation of the complex transient dynamic effects of earthquake shaking by a single constant unidirectional pseudo static acceleration is very crude. So, that is why it is one of the major limitation of the pseudo static method it neither consider the complex nature of the dynamic load it does not consider the time duration or transient nature of the dynamic load and other dynamic effects like frequency of excitation shear wave velocity primary wave velocity all these seismic waves which are travelling through the soil during this earthquake shaking none of this dynamic properties are considered in this pseudo static method only a single constant value is used. So, that is why it is a very crude estimation of the dynamic nature of a problem in a quasi static manner also the relation between that k and the maximum ground acceleration is also not clear suppose 1.9 g acceleration it does not mean that k value should be 1.9, but what are the advantages why people still use this age old pseudo static method because it is very simple to use as we have seen it is nothing, but an extension of static analysis only it is a quasi static or pseudo static as the name suggests and it is very straight forward. So, there is hardly any complexity involved in the analysis that is why many people many researchers many practitioners they preferred this method because of its simplicity no advanced or complicated analysis is necessary because of the nature of the problem. So, it uses the simple limiting state of equilibrium of the analysis which is routinely conducted by geotechnical engineers mostly the practitioners etcetera when they want to design any retaining wall in the seismically active region to consider the seismic earth pressure on the retaining structures. Now, let us move forward and now let us talk about the development of modern pseudo dynamic approach. This pseudo dynamic approach was originally proposed by Steedman and Zeng in 1991 which has been further modified and the generalized solution for pseudo dynamic approach was given by Choudhury and Nimbalkar in 2005 for the first time. So, what is pseudo dynamic method? Let us look at this problem. So, this is again we are talking about the basic rigid retaining wall analysis this is the line diagram AB is nothing but the vertical face of the retaining wall this is the ground surface. This condition is showing the passive state of earth pressure that means wall it tends to move towards the backfill side that is why this is the seismic passive earth pressure this is the soil reaction this is the weight of the failure mass ABC at a particular failure assumed angle of alpha and these are the seismic inertia forces Q H and Q V Q H is horizontal seismic inertia force and Q V is vertical seismic inertia force. In the pseudo static method how we estimated this Q H and Q V nothing but Q H is coefficient of seismic acceleration that is K H times this W and this Q V that is vertical seismic inertia force was estimated as K V times W where K V is vertical seismic acceleration coefficient. But now we are proposing this pseudo dynamic approach which takes care of all this dynamic effects. So, what are the advantages of this modern pseudo dynamic approach over the conventional pseudo static approach? Let us look at it first like soil amplification which may happen in some of the cases of the soil as we have already studied that in the previous module on site response analysis that can be considered in the design that is the one biggest advantage of this pseudo dynamic approach which the pseudo static approach cannot do. Then frequency of earthquake excitation is also considered. So, this dynamic nature is considered at what frequency the earthquake motion is coming. So, that can be taken care of time duration of the earthquake that is the transient nature of the earthquake can be considered in this method. Phase differences between different waves can be considered amplitude of equivalent peak ground acceleration can be considered and it considers the seismic body wave velocities body waves means S wave and P wave both traveling during the earthquake. So, let us look at this basic picture once again during the earthquake we have this vertically propagating upwards this shear wave velocity V s and primary wave velocity V p. Now, why this is vertical that already we have described that if it comes from a large depth below the ground surface after several layers it will be almost close to vertical. So, it is a good assumption to consider the vertically propagating seismic wave like that. Now, the seismic accelerations which are considered for the analysis are expressed in the form of a sinusoidal motion. So, that is why the name pseudo is still there one can always say why this dynamic approach is still having this component of the name the pseudo because of the reason because earthquake motion will be random in nature it will not follow any sinusoidal or any particular mathematical function it will be fully random in nature. But to have a generalized design approach we cannot do the design with random motion in that case it will be a case specific design that is for each taken random motion you will get different values instead of that the practitioners or designers or the codal provisions will always look for a closed form design solution or generalized design solution. So, to do that what we have proposed we have considered the equivalent sinusoidal motion like once you have the random motion of earthquake take the area under the curve of that acceleration versus time history and find out the equivalent area in the sinusoidal form of the same acceleration versus time history which can be represented in this format. So, horizontal acceleration a h is now no longer a constant, but it varies with respect to depth from the ground surface that is z measured from the ground surface and time t that is up to which this earthquake is occurring which is expressed in this form that is 1 plus h minus z that is at a depth of z a small infinitesimal slice of thickness dz is considered.  Soil amplification factor is nothing but from the bedrock to ground surface how much the PGA value got amplified or the maximum value of earthquake acceleration got amplified. So, that gives us the amplification factor that non-dimensional value of amplification factor is assumed here to follow a linear distribution that obviously people can argue and can take different variation, but when there is no other solution one can fairly estimate the variation of f a as a linear variation with this expression this is nothing but a linear equation with multiplication of a h, a h is nothing but amplitude of the horizontal earthquake acceleration and sin of omega t minus h minus z by v s where this t is the duration of earthquake h minus z by v s it gives nothing but the phase as you can see this is nothing but the phase right. So, that automatically gives us the expression how this sinusoidal horizontal seismic acceleration varies with respect to z because there is a function of z over here and varies with respect to time because it is a function of time and frequency is also involved. So, frequency is also taken care soil amplification is taken care and shear wave velocity is also taken care of because shear wave velocity mostly contribute on the horizontal seismic acceleration as we already know.  So, that is why this expression is considered for both horizontal as well as vertical seismic acceleration which are now function of depth and function of time. Now, once you know the acceleration what you can do for this infinitesimally small slice what is chosen over here you can find out the mass of it and once you know from the geometry its mass of it you can multiply that mass with respect to corresponding acceleration to get the inertia forces. So, that is what it has been done let us look at here if you do not consider any amplification then the equation boils down to this that is amplification is 1 basically there is no amplification. So, in that case the expression for the seismic horizontal inertia force q h t will be nothing but mass of that infinitesimally small slice that is m of z times the acceleration h z will give you the seismic horizontal inertia force.  After doing this what is done here the details can be obtained in this paper Choudhury and Nimbalkar Dr. Sanjay Nimbalkar was my first PhD student this is a part of his PhD thesis work under my supervision at IIT Bombay in 2005 this paper has been published in the journal Geotechnic published by institute of civil engineers London this is the volume number page number. So, what has been done after finding out the Q H and Q V expression W is already known as I said then the limiting equilibrium of all these forces involved was considered and once you do the limiting equilibrium of all the forces involved in this two dimensional problem the total that is static plus dynamic passive resistance can be obtained like this which needs to be optimized with respect to your this angle of alpha. Remember in static case we need to optimize it with respect to only this angle of chosen failure plane alpha but in the case of dynamic problem it is not only you have to optimize it with respect to alpha but you need to optimize this with respect to duration of earthquake also in terms of the frequency of earthquake how it has been done I will come to that now. Let us see what is the coefficient of seismic passive resistance coefficient of seismic passive resistance which is nothing but our final design value which designers will always look for when they are doing the design of any retaining wall this is the closed form expression for k p e in this case this m 1 and m 2 are expressed by this you can see over here this parameter small t by capital t this capital t is nothing but time period which is related to the omega that is frequency as we all know and this small t is nothing but duration of earthquake. So, we have to optimize this value of k p e what should be the design value of k p e as we know for passive case it should be the minimum value. So, minimum value of k p e needs to be obtained with respect to a combination of this alpha value and this t by t value. So, that optimization has to be carried out it is an optimization problem to obtain the minimum value of k p e or design value of k p e which was not present in the case of static problem in that case we have to minimize only with respect to this alpha value. Now how to get the seismic passive earth pressure distribution over the entire depth this is one advantage of this pseudo dynamic method like in pseudo static method earlier as we have mentioned in most of the cases we were getting only the total value of the earth pressure except for one method where we have mentioned about that method of slices right otherwise we were getting the total value we were not getting the distribution, but in this case of pseudo dynamic method as we have already taken this infinitesimally small slices. So, at each level of the depth you are getting the design value of this p p e. So, automatically that gives you the distribution or it can be mathematically expressed in this form this is the variation of seismic earth pressure distribution with respect to depth. So, once you know the distribution automatically you know the point of application of the total passive resistance as well which will help you to put the reinforcement in your wall section when you are designing the wall fine. So, all these details are available in this journal paper of Geotechnic by Choudhury and Nimbalkar 2005. Now, let us see how the results are varying as far as the proposed pseudo dynamic method is concerned. So, for the seismic passive resistance you can clearly see now the seismic earth pressure distribution is fully non-linear earlier in all the pseudo static method we were getting linear earth pressure distribution which should not be the case because we know due to seismicity the earth pressure cannot be hydrostatic or the triangular distribution it cannot be a linear variation it will be a non-linear process. So, that non-linearity has been also captured in this pseudo dynamic method. So, these are all the advantages of pseudo dynamic method in addition to that what I have mentioned in the first slide of this pseudo dynamic approach. So, you can see the results this red line shows the value when k h equals to 0 that means under the static condition because k v we have considered for 0.5 times k h. So, if k h is 0 k v is also 0. So, this red line shows the passive earth pressure under static condition and as the seismicity increases as we know the direction of the seismic acceleration will act in both the directions whether it is horizontal or vertical, but we have to take the critical value for the design and what will be the critical value for passive case it will be the minimum one and minimum one is nothing but it should reduce with increase in the seismicity. So, that is what from the static case of this red line as you can see as the seismicity increases from k h value 0 to 0.1, 0.2, 0.3 g this value of passive earth pressure distribution under earthquake condition is also reducing. So, those are design values and as the seismicity increases the non-linearity of this variation is also increasing. So, that automatically shows that point of application which was in the static case at one third from the base of the wall is no longer at one third, but it is below one third for the case of passive earth pressure fine. Some more results when we are talking about the effect of soil amplification how this amplification effects the design value of this earth pressure. Let us see the seismic passive earth pressure coefficient when there is no amplification that means f a equals to 1, f a equals to 1 means no amplification factor. That time depending on this value of h by T v s you can see this is the variation of k p e for no amplification case, but if there is amplification in the soil if suppose your soil gets amplified 1.4 times or 2 times then in that case the design value of k p e is still decreasing what does it mean that means the design value should be much lower than what it is the case for the non-amplified soil clear. So, this criticality also can be captured in the case of pseudo dynamic approach which is not possible in the case of pseudo static approach. So, all these are advantages of pseudo dynamic method. This is another comparison you can see for this case of k h equals to 0.2 and k v equals to half of k h with this value of phi and delta. Mononobio-Cabe method which is pseudo static method that will give a linear variation or hydrostatic distribution straight line variation like this the red color whereas, the pseudo dynamic method in the passive case it is non-linear and this is the non-linear variation. You can always say the total value of the passive earth pressure there is that can be said almost similar for this particular chosen set of data value, but the passive earth pressure coefficient values may vary which is necessary for the design. Let us look at this values which is also available in this journal of geotechnic by Chaudhary and Nimbalkar 2005. This passive earth pressure coefficient the design value this dotted line is for Mononobio-Cabe with this rectangular boxes then this dotted line we can see with circles are proposed by Chaudhary in 2004 and the triangular one is the present study means this pseudo dynamic approach. You can see the design value k p e is minimum what we are obtaining in the pseudo dynamic method compared to the conventional pseudo static method. So, what we can say the critical value at the most desirable design value is proposed by pseudo dynamic model not the pseudo static model for the passive state of earth pressure which is clear from this picture also. Now, let us come to the next case of seismic active earth pressure and applying this new pseudo dynamic method. So, for the case of seismic active earth pressure on the retaining wall this is the line diagram this is the retaining wall planar failure surface is assumed again this is the active state of earth pressure. So, that is why this is the position of the active earth pressure seismic active earth pressure p a e at an angle delta with respect to normal to the wall and w is the weight of this failure wage q h is the seismic horizontal inertia force q v is the seismic vertical inertia force remember they act in both the directions. So, and we have to find out the critical direction of it by doing an optimization of analysis and f is the soil reaction. So, here also this infinitesimal small element is been considered at a depth of z of thickness d z z is measured from the ground surface and v s and v p are the shear wave velocity and primary wave velocity of the earthquake excitation. The details are available in the publication of Dr. Sanjay Nimbalkar's phd thesis work that is Choudhury and Nimbalkar 2006 in this geotechnical and geological engineering an international journal published by Springer this is the volume number page number etcetera. So, what we can see the similar approach has been adopted in this case it is the active state. So, the seismic inertia force in both horizontal and vertical direction is obtained in the similar manner, but when you are doing the equilibrium and finding out the p a e you have to do the proper analysis of all the forces involved and their corresponding directions etcetera to get the design value of this and once you get the expression for p a e next step is to do the optimization once again and this is the expression closed form expression or the design expression which designers will like to use always this is the k a e expression with m 1 and m 2 values over here. You can see here also the optimization requires with respect to the chosen alpha angle and this t by t ratio and here again we are getting the advantage of seismic active earth pressure distribution the variation of it with respect to wall which gives us the what the point of application of the total seismic active earth pressure will act that also will give us the idea. So, this is the result you can see over here this red line is the result for the static case and as the seismicity increases as we know for the active state that design value or critical value should increase right because in active case we maximize the design value. So, that is why as the seismicity increases the design value increases compared to the static one and also as the seismicity increases the variation of the active earth pressure distribution with respect to depth it is highly non-linear as you can see over here what it can be said the point of application of the total seismic active thrust which is one third from the base of the height of the wall and static case is no longer at one third, but it shifts upwards than one third in passive case it moves downwards in active case it moves upward. So, that gives us the exact position where and what amount of reinforcement in the soil reinforced soil wall when we are trying to construct and design a reinforced soil wall when we are trying to construct RCC rigid retaining wall where the reinforcement has to be provided that is clear from these results which is not available in the pseudo static approach. Again the variation of this amplification factor can be seen over here like when there is no amplification this black line this is the value of k a e the design value without amplification, but when the soil gets amplified during the earthquake process that material property also can be taken in this pseudo dynamic approach and you can see the design value of k a e is increasing can you see that automatically says that we need to take the higher value of seismic active earth pressure when we are designing our wall in a soil which is going to get amplified subjected to some earthquake motion. So, these details are available in the publication the effect of amplification etcetera on the seismic active earth pressure publication of nimble current Chaudhary in 2008 in the journal of earthquake and tsunami this is the volume number and page number. So, with this we have come to the end of today's lecture we will continue further in our next lecture.


Hi vlog, welcome back. I'm just popping on here before I share the vlog. I just wanted to say hi. This weekend Tommy put together this special little birthday weekend and it was just so generous and thoughtful and him and I obviously travel a ton together throughout the year but it's never really like that. It's never like activities and hanging out and just literally sitting on the beach and kind of doing nothing. Birthdays for me, I don't know about you guys but birthdays to me are a little bit more of a reset than New Year's and I was just thinking a lot on my birthday maybe because I feel like 26 is like an age that I feel like I'm getting older. Like this year I really was like, wow, 26, you know? And I was a little bit emotional and I wasn't emotional in a way that was like a bad sad but I was just feeling a little bit emotional on my birthday, like on my actual birthday and then I very easily sort of snapped out of it because we went on the trip and kind of celebrated my birthday more on Saturday. We had a whole boat day but yeah, it was a little bit emotional for so many reasons but I think foremost just like the person that I've become my 20s were pretty gnarly honestly like so many amazing moments in my 20s but so many just really horrible hard moments in my 20s and the coolest craziest thing about it all is that every single thing that I've been through and every single experience and situation that I've been put through has led me to where I am today but with that being said, I also kind of in my mid 20s realized that the work that I put in to my work into my content and to like who I am is part of the reason why I've evolved into who I am today and I just was feeling a little bit like overwhelmed and sad and happy and yeah, it was kind of weird. Honestly, not like it was weird because it was bad, more weird because I find myself staying so busy that I don't often think about that. It was kind of cool. There's that weird part that not many people talk about that has to do with growing up, documenting your life, being widely known but then not really known personally, like really personally. What I've shared versus what I haven't shared and I want people to be so close to me and know me so well but then there's a level of privacy that I have to maintain to be normal. Like what this job has afforded me is wild in my 20s. I've been able to create a brand, a community. I've been able to financially support myself. I've been able to travel. I've been able to get a house. I've been able to own cars and just the life that this job has given me and the community. It's pretty remarkable but I think with anything really amazing comes sacrifice, things that are really difficult. I struggle sometimes, especially getting older. I go back and forth a lot on what I should share and how open I should be. Honestly, the older I get, the more I feel this desire to become more private and that's a weird feeling when you've shared your whole life online since you were like 19, 20. Yeah, I think these are all normal feelings or not normal because it's not that normal to share your life online but these are things that I was thinking about the other day and things that I, the older I get, the more I think about. And another part of this I think feeling that I have also has to do with the fact that my business, which is honestly one of the most important things in my life, my brand, Dairy Boy, I don't always share a lot about what that has taken me to build that brand. I mean, there are a lot of influencers, a ton of influencers and there are a ton of YouTubers but starting a brand didn't just fall into my lap, like it really didn't. The brand that I built literally was my childhood best friend and I doing everything. We were doing the marketing, we were doing the production, we were doing the sampling. There was only two of us and we made a ton of mistakes and we felt the pain of not having specialized employees. We had some amazing people help us along the way but making the transition to opening an office in LA was a huge, huge step for me and my brand and my life and with that change that needed to happen and I needed to hire more people. In order to scale my business out to the place that it needed to be, the place that it needed to be in order to get the quality and quantity of goods that I needed I had to open an office and I had to hire a production manager, I had to hire a marketing manager, I have a designer now, I have someone helping me oversee my team. I have just a full team now for my brand and I've just been feeling like a lot of different emotions recently and most of them really, really positive. Just feeling a shift in my life. Obviously I had probably the biggest shift of my 20s when I moved to Connecticut and I entered a really healthy relationship. That was obviously a very pivotal moment for me in my 20s. That's kind of when everything sort of started shifting towards me living the life that I really wanted to live. But yeah, the office and then my 26th birthday and just all these things. And also wanted to completely different.  Now, Tommy's always been in Florida for his training but I'm spending more time in Florida now. So I've been spending a lot of time in Florida. Like I really consider this home now here and I still have my house in Connecticut. That is really like my sanctuary, my little cottage in Connecticut with my horses and it's just like where my family and my best friends are. And I'm not gonna get rid of that house. I really love Connecticut. But now with the office opening in LA I was kind of like feeling stressed. I was like, I'm sure a lot of you felt stressed for me. Like how is this girl going to be in Connecticut, be in Florida, travel on the tennis tour and be in LA. And my last trip to LA, like when I was just there right after the Australian Open. I had this sort of moment of realization. A lot of CEOs, entrepreneurs, business owners aren't always influencers. So you don't really see their lives and I kind of realized that it is quite normal for people to have to be by coastal for work. And I'm gonna have to kind of grind and travel a lot and fly out there a lot. And it's gonna be tiring sometimes. But that's what I need to do to build this brand to the place that I know it can be at. There are so many like amazing things that we're going to be changing in the brand, launching with the brand, you know, capsule collections, home goods. There's so much and I absolutely love it. And honestly, it's just really important for me in my 20s in this time to put in the work and to be running around, doing the traveling, going to LA, going to Connecticut, going to Florida, traveling on the tennis tour. And it's a lot and that's okay. You know, it's okay that it's a lot. And I'm really just viewing LA as like work. You know, it's work. It's not really social for me. And you know, like I might meet up with some friends because I have friends out in LA and like go to some events. But leave in the office all day when I'm there. So if I end up do getting like a small apartment in LA literally just to keep my stuff, just for work, like I don't need to make it feel like, you know, another home, you know, like I already, I'm in Florida and Connecticut. I just, I'm feeling less stressed about that. The fact that like, it's just work. It's just work and I want to put in the work now and then hopefully that will all pay off in a few years. But anyways, I've been ranting for like, I feel like 10 minutes now, but I just wanted to kind of touch base with you guys and say hi and I hope that you enjoy this little vlog. I am in Florida for maybe a little less than a week. And then I'm heading back to LA for a photo shoot that I have to go to. And then I'm going to go back to Connecticut finally. I have not been back to Connecticut in a minute. So it'll be Florida vlog, California vlog. Maybe I'll do a little photo shoot vlog. We're going to a really cool location. So yeah, maybe I'll vlog that. And then back to Connecticut for home vlogs. I know that you guys miss those vlogs and I do too. It is just really cold and miserable right now at home. So I've been like really enjoying this whole Florida in the winter situation. But I'm planning on spending more time in Connecticut in the spring, a little bit in the summer and then the fall. But I love you guys and I hope you enjoy this little birthday vlog. Hanging pots and pans over there. Oh. Anyways, good morning vlog. We are currently in the Bahamas for the weekend, which is such a treat. Literally a 30 minute flight from Florida. If you can't tell, my face is super swollen and I'm really, really tired. The jet lag has been really bad coming back from Australia. For me, I went to bed really early last night at like eight, 30, and then I woke up at like four a.m. And then I fell back asleep at like seven. But anyways, we are here just for, got in last night for the whole day today and then leaving tomorrow night. So we're just gonna be relaxing and I think we're gonna start the day off at the beach and then we might go on a boat later. And then I think Tommy wants to go fishing on Sunday. But I thought I would vlog for you guys. I've been vlogging a lot on my iPhone recently, which is funny. I either use my really, really high quality, huge Canon Rebel, which is super high def or I use my iPhone because I haven't been loving my Canon G7X, which is what I'm filming on right now. I don't really love the quality. I have broken so many of them and I just have a lot of issues with them. So I've been really loving my big camera and my drone and my iPhone. I feel like the iPhone captures shots that are, I feel like more personal because it's much easier for me to just like grab my iPhone quickly on the go. It's not like a whole production. So I've actually really liked the contrast between the high quality B-roll and the iPhone. But I definitely feel like I need a higher quality 4K vlogging camera.  On vlogging cameras or cameras, you don't even have to be a blogger, but cameras that you guys like or cameras that could replace my G7X. Thought you ordered two for yourself, but I'm a pirate. We're pirates.


West Virginia High School football practice entered its second week Monday for programs across the state, with the exception of Chapmanville, Logan and Mann High Schools. We had a chance to talk with Mann coaches Harvey Arms and Mike Crosby, along with athletic director Billy Jack Dickerson about the current situation and frustrations they face during the pandemic. They tell us that they have a system in place to make it equitable for all that are involved. I'll have to see that in action. I'm sure with just like all these other management systems that they've come up with, there'll be flaws. I feel sorry for those folks. I really do at the SSAC because they were getting hammered today with questions concerning band, concerning dance teams, concerning cheer, concerning everything that revolves around fall sports. On August 14th, the state of West Virginia introduced a new color code system to determine what counties were safe to have athletics in. Logan County has been in the red since the beginning. This prevents them from having any games or practices. Well, we, of course, we knew that that was going to shut us down. And from that point on, we were pretty much unsure. A lot of people don't understand the metric. I'm not sure I understand it to tell you the truth. And we knew we were going to be down until further notice. And that's all the information we had and really all the information we still have. Before I left the house, we were on, I don't even know what number, Zoom meeting that we had had with Mr. Dolan of the SSAC. And they really don't have answers. There's no way to answer all of the questions that are going to come up. The meeting was centered around attendance to sporting events. And depending on this color code system, it's going to be a nightmare to figure out who gets to come. You know, we have a, in today's society, we have a lot of split families. You know, the child lives with one parent some of the time and other parents some of the time. You're trying to figure out who is the guardian at a particular point, who gets to come to the game. It was just a nightmare, assuming that we would come out of red and move to orange. Then the first actual contest that man high school could participate in would be on September the 16th. And we're going to have to reach out to schools like Mount View and West Side and say, look guys, we're sorry, but under this current color code system, we're not going to be able to fulfill our contract. And if possible, you need to find a substitute for our game. Head baseball coach Mike Crosby has witnessed firsthand the devastation the pandemic has taken on high school sports. I can't imagine somebody coming to me my senior year after putting all that work in. And that's one thing about our boys is as soon as football was over with with with coach arms, the ones that wasn't playing basketball, man, they were working hard on their own. And I mean, they were in there every day grinding and busting it and to look at him and and tell him to take up and play. Really, this was about a two to three year thing, because I had two to three years ago, I had started a bunch of freshmen and sophomores. And we were looking forward to this past year. And then not to be able to play it. And they were looking forward to it too. It was it was heartbreaking. Although the outlook is currently cloudy, coaches offered their advice for athletes to remain positive. We've just emphasized, be ready when the time comes. If if we get this opportunity, we have to get at it and get at it quickly.  Try to find the positive in everything that the positive that we found in baseball for the underclassmen was, you know, a lot of those that take it for granted now know what it feels like to have it taken away. So if nothing else, it it helped to work ethic of a lot of the younger players. But don't hang your head. Have faith in the system. Hope that it works out. Trust in your coaches. Do what they tell you.  Try not to be negative about this thing and just hope that we as a county with that new color coded system, we as a county will take the precautions, the guidelines that's been put down and hopefully get out of this thing as soon as possible and and coach arms and and the hillbillies and Logan and Chapman'sville can all resume their seasons and start practicing and at least get some games in this year. Currently, if man were to play football this season, they would open the season against Mingo Central on September 18th. For details on this and other stories, visit mountain dash top sports.com or visit our Facebook and Twitter pages with mountain top sports. I'm Cody Davis.


G'day, how you're going? Welcome back to Bootlossophy and if we haven't met, my name is Tech. I'd like to first acknowledge the traditional custodians of the lands on which I live and work, the Wajik people of Nungabuja. And today I'm going to tell you about how my Jim Green African Rangers have worn in the last three months. These are my African Rangers from South African Bootmaker Jim Green. I bought these in August 2022 and in case you're watching this sometime way in the future, it's now November 2022. You can watch my unboxing and initial impressions review up here. And that's probably an interesting video to go back to after this one to see if any of my impressions have changed. I haven't actually bothered to rewatch it because I didn't want my memories to colour what I think now. So let me know if you see any change. So let's start with what I see. It's hard to categorise the African Ranger. It's not quite a work boot. It's short, but it's not quite a chukka boot. It has a wage sole and is pretty round and wide at the toes, but it's not quite a hiking boot. In fact, this is a very distinct aesthetic, especially with this very wide double e-width round toe shape. It is a rugged looking boot though, and maybe we can best get to understand it once we know what it was made for. In parts of Africa, some species of animals are being hunted and poached to extinction. Rhinos, for example, are being killed and left to rot only for their horn.  In order to counter this, South Africa and some other eastern and central African countries have game and animal defence rangers that patrol and manage wildlife reserves and national parks. I'm assuming it'll be obvious to you that these rangers do not earn a ton of money and do a hard job in the bush, often wearing poor and unsuitable footwear for the conditions. 50% of rangers don't have access to enough boots and bush gear. Over 40% of rangers have to buy their own boots. Jim Green designed the African Ranger for these rangers. As a company, Jim Green values the future of their wilderness areas, so they got together with the Game Rangers Association of Africa and put out a survey to rangers working across Africa to say what they needed in footwear. And from that, they designed the African Ranger, or what they call the boot designed by rangers for rangers. While the boot is designed for comfort, durability and an affordable price, Jim Green also do a bit and donate a pair to a ranger for every 10 pairs sold. Last month they reached a milestone of 1200 boots allocated for rangers, so well done Jim Green. So with that being said, you can now see that this is what I think I'd call an ankle field boot designed for the African bush. A tough low ankle boot with a wide round toe box capable of walking on sand, undergrowth and rocky terrain as much as for walking into pubs, workshops and working in your garden. Before we go on, let me admit to change the laces from the green ones they came with to these red ones from my cobbler because I think they actually look better not necessarily because of any quality issues with their own green laces. This is where I segue into saying that they are clearly casual boots and talk to you about what you can wear them with. I'm not going to do that. You'd have to be blind or listening to this without watching the video because these are clearly bush slash work boots, full stop. What do you wear them with? What do you want to wear going up bush? And I imagine to the horror of my American viewers in Australia as I imagine they would in South Africa. That includes shorts. They are a different aesthetic. In fact when I released my unboxing video I got a few comments that the big round toe was ugly. I don't think so. If I want to go out on date night, sure I'd choose something else. Going into a professional office, even if it were casual Friday, I'd choose something else. But if I were hiking in the bush or going to dig a hole or working in a workshop or on a construction site why wouldn't I wear these if they're comfy, which they are, and they're tough, which they are. They are fit for purpose. My masculinity is a little more secure than wearing that look silly in big round toe boots. So let's turn to look at the South African family company that make these. Jim Green is a three generation old family business which started as Crouch Footwear in 1987. Eventually Jim Green Footwear was then spun off in 1992 with the vision of making tough boots that are made to last over wear and time. Jim Green quickly developed a reputation amongst local communities and eventually becoming a household name across South Africa. The Crouch family still own Jim Green with third generation Gareth Crouch and his brothers working in the company now. Jim Green is actually the name of a frog that lives in the KwaZulu Natal region where the company is situated. Apparently it's a favorite snack of local river fish. So Jim Green the boot company used the logo of the frog as their company logo. Jim Green boots are handcrafted locally in South Africa and all components are also locally sourced. It's very important to them to support their local economy by supporting the local supply chain. The factory in Peter Maritzburg in the KwaZulu Natal province is one of the last ones in the country still paying their workers 100% of the legal wage rate. After the government relaxed the rate due to the economy many other businesses started paying at reduced rates. Walking the talk seems to be part of their vision and values because they continue to give year-end bonuses to their workers depending on the company results and a few years ago they even gave their workforce a 10% stake in the company. I haven't spoken to any of their workers obviously but as a management practice this is not only generous but it really seals the deal in developing teamwork and a series of belonging. Over and top all of this they haven't skimped on production and they make their boots in the same way they were made from the very beginning at ongoing value driven prices. From what I can see this company is as big in its goals as Africa itself. Let's dive into how these boots are made and as usual I'll start at the bottom and move on up. Oh by the way you might also be interested in subscribing to Jim Green's own YouTube channel. There are some great videos there about how the rangers operate in the bush as well as pretty cool how it's made videos. So okay let's start with the outsole. It's a proprietary wedge sole designed to provide a grippy surface with these deep ridges. It's a rubber compound sole and the feel of it is soft not unlike a Vibram Christie sole but in a brownish gray so less prone to discoloration and more suited to red mud and sand. The softness of the rubber and the flatness of the sole is designed to keep the rangers' footfalls quiet as they walk through and patrol the African bush. The outsole is glued on to a leatherboard midsole and I think it's a combination mid and insole. Not being welted there's no need for a cavity filler inside so the steel shank is glued on between the wedge sole and the midsole. As an assider shank is a thin piece of hard material usually steel that gets inserted under the arch. It gives you support under the arch. I've never really understood why wedge sole boots need a shank. There you are. The uppers are sewn on to the midsole using the stitch down method of construction. In stitch down construction the uppers are flared out all around the boot and sewn directly to the leatherboard midsole-insole combination double stitched in this case with a 2.2mm braided nylon cord. This along with the fully gusseted tongue makes for a dust free construction method and to an extent water resistant as well. Stitch down method having the uppers flared out means that water and mud should be pushed over and off the boot. There's not a lot of exposure to wading through water I wouldn't have thought for the rangers so despite the leatherboard midsole and the shortness of the boot it is fit for purpose. And of course stitch down boots can be resold by some cobblers. Not all cobblers have the skill or equipment to remove the stitch down stitching and then replace the stole by re-stitching into the original soles in the uppers. The way the uppers are designed and put together is worth talking about. There are numerous pieces of leather here. There's the two quarter pieces. Then there's this vamp piece that attaches to the quarters and goes all the way to form the toe box. Then there's the real toe cap that is glued and sewn on top of the vamp piece at the toe box. The heel counter cover come back stay with the full flat pull tab is sewn on at the heel. At the back of it is the Jim Green frog logo. The collar is made of a double layer of leather with padding in between. The hardware is reinforced by two layers of leather and sewn onto the quarter pieces and then the fully gusseted tongue is sewn onto the quarters and the vamp. The tongue is wide and generous and folds as you tie the laces to kind of give you some comfort from the facings. There's a lot of leather pieces making up this quite complex design. This leather is their own crazy horse leather. A full grain leather that's lightly buffed and then wax and oiled. Basically a wax newbuck. Crazy horse is bovine not horse and it's called crazy horse only because it was widely used as leather for saddles and horse tack being soft but durable. Apart from the tongue the leather is slightly over two mil thick so it's quite sturdy weight. Not to mention the double layers you get the toe box, the heel and the lace edgings. The toe box and heel counters are stiffened with something like a celastic stiffener. Celastic is a textile that's impregnated with cellulose nitrate and can be heat activated to be moulded to a shape you want. When cool it forms a stiff shell. The inside of the boot is unlined including in the toe box area so in fact if you peer in you can see the underside of the celastic stiffener at the toe. It looks and feels like starch canvas. Directly inside on the footbed is a leather board that the uppers are stitched down into. Jim Green provides the boots with their own light rubber removable padded insole which provides a little extra arch support. It's not going to win any prizes but it's comfortable enough. If you want you can always remove them and put in your own comfort insole. The hardware is not like the hardest metal but they are sturdy. I can't bend the speed hooks trying moderately hard and they feel secure. They are backed by washers which is crazy when you consider the price so they're not going to tear into your tongues. Overall I think quality is as good as you get for what this boot is. Simple, no nonsense, focus and comfort durability and affordability. Crazy horse leather is basically a wax new buck. This means that the surface is relatively unprotected so if you want to be careful of the presentation of this leather if it gets spilled on clean the surface of the leather immediately with a slightly damp cloth but don't use any chemical based cleaners or alcohol. On the other hand it is a rugged leather so you don't have to be paranoid about it. It should be able to hold up to getting wet for reasonable periods of time and is rugged enough to hold up to some abuse. In fact if you want patina this is the leather for you. If it does get wet just dry it out naturally.  If it gets lightly scratched you can use a dry cloth to rub over the scratch and moving the oils in the leather will help to smooth out some scuffs. If it gets really dirty and dry you can use saddle soap and you can use a natural conditioner that's more of a cream or a balm. Try to avoid chemicals or avoid one that's too oily or waxy so avoid something like Venetian shoe cream. I have used Light Smear Big 4 on another crazy horse pair of boots and while that initially darkened the leather it dries back up. I'd also recommend RM Williams' leather dressing or conditioner cream. All in all though not only is crazy horse a tough rugged leather so is this boot so my advice is go easy on the conditioning. Just brush, keep it clean when it gets dirty don't worry too much about scuffs and marks and love the patina that develops. Now let's turn to sizing, fit and comfort. South Africa being a Commonwealth country like Australia uses UK sizing numbers like Australia. So my UK Brannock size is a 7.5 in an average width. In US sizing numbers all you do is go up one number so my 7.5 UK is equivalent to a US 8.5. In this they run true to size so these are 7.5. They actually fit me quite well. When I first got them I thought they might have been a half size small because I felt some pressure at the tip of my big toe. I think now that I've been wearing them for three months I think they really are the right size. The pressure I felt and to some extent still feel on my big toe is I think down to the really firm structure of the toe cap. Being a real toe cap meaning two pieces of thick leather at the toe plus the stiffener inside that means that I feel that pressure at the top of my toes it doesn't bend that much. Pressing down on the toes though I feel that I got a little bit less than the thumbs width between my toe and the tip of the boot which is fine for length. But what it is until it breaks in the toe is so stiff that it doesn't quite flex with the bending of my toes when I walk. So the right size but as comfy as they are underfoot the rugged leather does need some breaking in. The initial spots are the aforementioned toe area and to some extent the corners of the collar. When the laces are tied up to the top they're basically made of four thicknesses of leather. That corner did cut into my ankle. To start with I just laced them only up to the first eyelet until the leather warmed up and softened. In the last three months I've worn these quite regularly as regularly as 70 pairs of boots in rotation will allow because I wanted to break them in properly being pretty tough leather. I wear them every weekend if not all day in the weekend we go for our weekly one to two hour hikes in the bush reserves near where we live or always when I'm digging in the garden or working at my bench in the garage. During the week I wear them two or three evenings a week after work and during the day maybe once every week or at least once every fortnight. The only thing is I've missed what I wanted to wear them for. When I travel to the Kimberley region of north-western Australia or to the Savannah bush of the north of the Northern Territory working with Aboriginal communities on their cattle stations or in their Savannah burning carbon projects I thought these would be perfect for that sandy, pinned-down desert and black soil plains mud and grit but unfortunately with COVID still around and those communities being more at risk I haven't been able to work up there. Nevertheless I think I've been able to give them a good workout and I can say that these are only about half broken in. The collar and the uppers are definitely softer but that toe box is still making me conscious of that toe box being there. If I were to really break these in I think after about two weeks where they would have warmed up but the toe box would still need work for another two or three weeks of constant and perhaps more rugged wear than I've been able to put them through. Maybe I'll bring them back out to show you next year and we'll see how much better they are then. Jim Green don't sell in Australia but they do have a US website for Americans. In Australia I go to their South African website which is all the W's Jim Green footwear or one word .co.za I'll put a link below. On their South African website they sell for just under 2,000 rand which is about 170 to 180 Aussie dollars a plus postage. They're more expensive if bought from Amazon at about 290 Aussie dollars but I think that's because you get the price converted through US dollars so it's a double conversion. Direct from South Africa if you get the exchange right that's value for money, no doubt about it. Just some full disclosure though Gareth let me buy this pair for half price but I did pay the full postage. I've made it clear that my reviews would be at full and honest objectivity so I hope you can see that I've given you all the good and the bad. You know, I can't really compare the boots and their price for anything else they kind of stand in a class of their own but taking what they are stitched down, tough, made for African rangers simple and no nonsense casual work or hiking boot under 200 Aussie dollars is pretty amazing. The construction is perhaps not built like some heritage boots I'll give you that. They do use leather board. The midsole is a midsole insole combination there's no lining in the toe box you can even feel directly the stiffener material the removable insole is not top notch foam but consider the price and what these were designed for they were not made for working on construction sites they were made for walking out bush on sand and rocks and they were made to provide durability and comfort at an affordable price where it matters there's a double layer of over 2mm thick leather I have no doubt these will last if you're not an African ranger if you make these to do some light manual work with them they're fine if you get these like I did to go bush in deserts savanna and the low brush in northern Australia they're more than fine if you buy these to wear casually like tough chuckers they'd be great so all in all quite a few pros for what they are not many cons and that's the wrap up folks I'm going to have quite a few more boot review videos coming up to Christmas I'm finally going to review some of my Truman boots as well as my White's MP boots and some other interesting brands coming up so if you don't want to miss them make sure you click on the subscribe at the bottom and of course if you like this video please click on the like and help me grow my channel by getting this video suggested to more boot crazy people out there thanks for that and take care and I'll see you again soon bye


The DuPont Company of Wilmington, Delaware, makers of better things for better living through chemistry, presents the Cavalcade of America. Tonight's star, Miss Loretta Young. Tonight's DuPont Cavalcade starring Miss Loretta Young is called Pwither Thou Goest and begins in the mountains of Tennessee on a Saturday afternoon in September in the year 1826 and with a girl named Eliza McCartle. The first time I set eyes on Andy Johnson, I was standing at the gate of my house and coming toward me down the dusty road, I saw him. He was leading a blind horse which was pulling the most ramshackle, creaky cart in the whole world. Oh, excuse me, Miss, but could you tell me what town this is? Why, you're in Greenville. I'm right obliged to you. Could you tell me, is there a tailor here in Greenville? There is indeed a fine tailor. Oh, I see. I'm mighty obliged to you. Is something wrong? Well, I don't suppose Greenville will be big enough to support two, Taylor. I don't suppose barely enough to support one. Look, I don't want to seem forward, but my name is Eliza McCartle. Oh, I'm Andy Johnson. Come up from Carolina, my family and me, up across the mountains. Oh, it's a long way to come and a hard way. You must be tired. Yes, we are. You don't suppose, do you, Miss Eliza, that be empty cabin somewhere we could get the rent up for a few days? Well, Mr. Armitage, down at the store, could tell you that. If you'll be good enough to follow me, I'll be glad to show you the way. Oh, I think you can. Morning, Mr. Armitage. Good morning. This is Mr. Andy Johnson. He's come to Tennessee all the way from Carolina. Mmm, looks good, doesn't he, on his hands and knees? Oh, don't mind him, Mr. Johnson. And, Mr. Armitage, I've come to inquire about renting an empty house. Oh, you and John Pringle fixing to get hitched? A figure, pardon, Mr. Armitage. You can't stop a man from guessing. No, the house is not for me. It's for Mr. Johnson. Hasn't Mr. Johnson here at town? I have, Mr. Armitage, a civil town. Well, he's got spunk. A question is, has he got any rent money? The answer to that question is no. That's what I thought. But I have got needle-thread thimble and shears. I can pay rent by making your coat out of that, uh, their bold cloth on your shelf. You can? Yes, sir. A coat with tails on it? Yes, sir. You have rented yourself a house, Mr. Johnson. Now, let's see what kind of coat I get. I used to pass by and see him sitting cross-legged on the table. His needle winking through the cloth, his fingers working very fast. Very sure. It was on the second Tuesday that he made me a business offer. I could pay you 15 cents, a cash money. For doing what, Mr. Johnson? Reading to me. Never had an education. Would you help me learn by myself? Commencing by reading to me. Couldn't rightly take money for reading to a person. Why not, Miss Eliza? Well, people don't get paid for reading to people. Well, in tailor shops they do. Once a cloth is cut, fingers can sew almost by themselves. By themselves? That's what I mean. While fingers work, ears can listen. I couldn't take pay. I'm sorry. Excuse me. Guess I shouldn't have brought it up. Shouldn't have, Mr. Johnson. Thank you, Miss Eliza. Do you really mean you never had any school in at all? Not ever? Would you mind handing me the shears? Thanks. Ford died when I was five. More took in washing. She couldn't afford to send me to pay school. Weren't any other kind in Raleigh. Got the habit of going into a tailor shop in Raleigh. The journeyman and his boys sat cross-legged while they sewed. And they'd pay somebody to read. I sat in a corner and listened, making myself small so nobody'd notice. And that was your education? Yes, Miss Eliza. Well, who taught you your letters? I did. I kept asking one of the men by the time I got to work there. I knew my A to Z. Well, didn't you ever go out to play with other children? Learnings play, especially if you never had learning. Mr. Johnson, I'll be very glad to teach you to read while you work. I thank you kindly. But it won't be for pay. I'll do it for friendship. Now, listen to this, Mr. Johnson. It's from the Bible. All right. And she said, Behold, our sister-in-law has gone back under her people, under her gods. Return thou after thy sister-in-law. And Ruth said, Entreat me not to leave thee, or to return from following after thee. For whither thou goest, I will go. And whither thou lodgest, I will lodge. Thy people shall be my people. And thy God my God. She did all that for friendship. Yes, Andy, she did. Only it was for more than friendship, for love, for loyalty. There's another part later on that I like. Oh. Why have I found grace in thine eyes, that thou shouldst take knowledge of me, seein' I am a stranger? You'll learn that by heart. I think I know the whole book of Ruth. If I hear a thing a few times, I know it. You're an unusual man, Mr. Johnson.  Oh, no, no. You're different. You're too sober, maybe, almost bitter. You know, you should laugh more often. Thank you. What have I got to laugh about?  I'm a grown man, and I can't write my own name.  Eliza, it chokes the breath out of me. You called me Eliza. I won't do it again. I'm sorry. I beg your pardon. Oh, but I want you to. You better not come here anymore, Ms. McCartle. I'll teach you to write. Andrew Johnson, do you hear me? I will teach you to write. Your name, letters, everything. Why? I believe in you.  Ms.   Don't say ain't. And I ain't gonna be takin' your time when there's Greenville Gentry who might be a courton. Why have no interest in the Gentry of Greenville, and stop sayin' ain't? I'm ignorant. I talk ignorant. Not like John Pringle. I've seen you with him on the street.  I'm being sensible. Greenville hasn't got room for two tailors. The work I got from Mr. Armitage will be done in a week. I'll believe in Greenville, Ms. McCartle. Leavein' for good. Because he thought he wasn't good enough for me. Because he couldn't write his own name. Because he was poor.  The travel to the town of Rutledge, 75 miles away. Winter closed in, and there was no word of Andy Johnson. No word until spring when Storekeeper Armitage sent for me. Your friend Andy Johnson has built himself a fine thrive in business.  Well, I'm glad to hear it. No, you're not. Oh, but I am. I am. I wish him well. I wish him success and good health and contentment. Not in Rutledge. His place is right here, in Greenville. Well, I'm afraid there's an ending to bring him back here. Oh, but there is. Well, I can't agree with you.  It ain't mine. No, you're exaggerating, Mr. Armitage. We, we knew each other for a little while, and two young people who just came together briefly and then, then went apart. All he wants is an excuse to come back here. There's no work for him here. Greenville already has a tail. Who's pulling up stakes? What did you say? Yeah, the old tail is quitting. If you hadn't been moping, Liza McCartle, that wouldn't have been news to you. It's been town gossip since January. But Mr. Johnson has a thriving business in Rutledge. Why would he come here?  Such things just didn't happen in true life. Then why was it happening to me? Why did I go to the South Road each day and listen for the sound of a creaking cart? And finally, when I heard the sound and saw the sound and proved what was causing the sound, why did I run away and hide in my own room? Sleeping, Mother? Well, there's someone here to see you. And it isn't John Pringle. Oh, my hair. Oh, Mother, please tell him to go away. Say that I'm, just say anything to him. Oh, there's nothing wrong with your hair, Liza McCartle. But, my face, Mother. It's a good face. You know, I shouldn't be arguing with you. I should be more calculating and want a rich man's son for you. Someone like John Pringle. But, my dear, there's something about this young man that makes me wish I was 20 years younger. Oh, Mother, what are you saying? I'm saying I'm a blazing woman.   There, that's better. Get in the garden waiting. Run, my dear. I know I'd run. Your face has changed a little. Where is it? You look older. Oh, well, I am older. You look paler. I'm glad to see you. Oh, I've come back to be the tailor or green pick. Oh, yeah. Some other tales, man. That isn't the only reason I've come back. No. I love you, Liza. But, at this moment, I'm not asking you to marry me. You're not asking? I've got too much respect for Liza McCartle to ask a man who can't even write down his own name properly. Properly? Yes, ma'am, who can't even write his own name properly. That's more proper. Is that all? Well, don't make fun of me, Liza. It's a terrible thing for a grown man not to be able to write. I'm serious. I'm serious, Andy. And I ask you again, is that all? That's all, Liza. Oh, well then, sit right down on that rock. What for? Just sit right down on that rock there and wait for me. Where are you going? I'm going to bring a copy book. Andy Johnson, I'm teaching you how to write. Now, don't go away. Looking for someone, Miss Liza? Oh, oh, John Pringle. What are you doing here? Expect someone else? Well, when I went inside, I... Mr. Johnson asked me to pay his regrets. Mr. Johnson did? He did, ma'am. An urgent matter of business took him all. John, you didn't quarrel with him. Oh, I never quarreled with tradespeople, Miss Liza. That's mighty condescending of you. Where did he go? Well, I gave the fella my measurements and he agreed to make a new suit of clothes for me. I explained that I wanted it in two days because on Friday I'll have a new horse and rig. And you wouldn't want to go driving with a gentleman and a new rig but an old suit, would you, Miss Liza? John Pringle, I'm going to marry Andrew Johnson. Well, there's no quality in the man, Liza. We won't discuss him. You're throwing yourself away. And they won't discuss me. Then we'll discuss me. You know what I have to offer? Yes, John. And thank you very much. Is that all you have to say? Yes, and I happen to be very busy. I'm engaged in teaching my future husband how to write his name. And now if you'll excuse me, John, I'll just see where it's gone. The DuPont Cavalcade continues, starring Miss Loretta Young as Eliza McCartle and Wesley Addy as Andrew Johnson. This is a story that took place 125 years ago in the mountains of Tennessee. The simple story of a tailor and the girl who loved him. Why did you go away? Well, I have nothing to give you. Seeing that man, I realized it. I'm entitled to a better explanation than that. It ain't good to be poor. Isn't. Speak grammatically.  Speak grammatically. Oh, you're wasting your time with me. I'll be the judge of that. You'll be poor. Well, it's no disgrace. What ain't no honor either. Isn't. If you say ain't once more, I'll slap your face. You'll be poor. Have you ever been real poor? I've seen my mother poor.  It eats all the goodness out of a person, all the woman out of it. Are you finished? She gets old before time and bitter before time and resigned to die before time. Now, look here. John Pringle intended to humiliate you. Why did you allow him to do it? I ain't saying it. I told you I'd slap you if you said ain't. I warned you. You got a temper, ain't you?  Yeah, that could be.  I was never more ashamed. Well, he asked me to make him a suit of clothes. I'm a tailor. Well, have you no pride, Mr. Johnson? I don't know if you wish. No pride. Have you no self-respect then? If you wish, no self-respect. Oh. But John Pringle will give you a fine house. Your children will never know want. They say he'll stand for the legislature and he'll be elected. He's the one who'll amount to something. Oh, speaking like little children, both of us. Andrew Johnson, everything spoken between us is idle and senseless. I will stand in church on Sunday and I will say aloud to all the townspeople, I wish to marry Andrew Johnson. He does not wish it. Well, you'll say a lie then. Is it a lie? I'm nothing. I have no right to you. Then I have rights which I must respect. Sit down in that doorstep of your shop. Sit down there and take this copy book in your hand. I like that. Sir, don't interrupt me, don't you dare. Now, you'll copy each letter I've written down. Capital A, small A, capital B, small B, capital C, small C. Each letter will sit on the ruled line. It will not stand up the line and nor will it slip down. Because each letter will have respect for itself and you will have respect for yourself. Your ink, Andrew Johnson. Your quill. Please begin. Yes, Eliza. Stop digging. Your writing not plowing.  Now remember that and do it better. Yes, Eliza. You blotted the paper again. Don't splotch. Write your letters. Don't smear them. Once again. Yes, Eliza. Don't cramp your writing. The only right and worth reading is written in a free hand. Yes, Eliza. That's better. Andy Johnson, you exasperate me. Aren't you ever gonna kiss me? Yes, Eliza. He worked hard. It's that cross-legged in his shop tailoring for the people of Greenville and I read to him while he sold. I read the Constitution of the United States. I read the Declaration of Independence. I read the speeches of Thomas Jefferson and James Madison. I read the laws of the state of Tennessee. I read hard facts to him and his mind was like a sponge. Whatever I read, his mind took up and held. He learned to put on paper the things in his mind. He learned well. Very well. One day he put his needle down and he gave me his copy book. I wrote it down this morning. It's good writing, Andy. I didn't copy it from the book. I just put the words down as I remembered them. And treat me not to leave thee or to return from following after thee. For whither thou goest, I will go. And where thou largest, I will large. Thy people shall be my people and thy God my God. Where thou diest will I die and there will I be buried. The Lord do so to me and more also if ought but death do part thee and me. Oh, Andy. I have spoken to Squire Mordecai Lincoln Eliza. He will marry us. My husband, Andrew Johnson, an ordinary man. By day he was a tailor. By night he read the law. He read the law and he began to speak to other men. The people listened to him. First a few, then many. They made him a county judge. Then they sent him to Congress. They made him a governor at Tennessee. They made him a vice president of the United States of America. There was a shot fired on April the 14th, 1865. A shot that was fired in Ford's theater in Washington. A shot fired at a man named Abraham Lincoln. Is Mr. Johnson ready? He is, sir, a Bible. On the table, sir. Oh, thank you. I believe we may begin. Andrew Johnson, place your hand upon the Bible. Repeat now after me. I do solemnly swear. I do solemnly swear that I will faithfully execute. That I will faithfully execute. The office of president of the United States. The office of president of the United States. A tailor boy, born in Carolina, succeed in a rail splitter, born in Kentucky. Two men who lived and died so that the Federal Union of the American States might be preserved forever. One of them, Andrew Johnson. My beloved husband. To Miss Loretta Young, Wesley Addy, and the Cavalcade players for tonight's play, Clither Thou Goist. Miss Loretta Young is currently starred in the Metro-Goldwyn-Mayer production, Cause for Alarm. On tonight's Cavalcade, the part of Andrew Johnson was played by Wesley Addy, and the script was written by Morton Wishingrad. Original music was composed by Arden Cornwell and conducted by Donald Boris. The program was directed by John Zoller, Mrs. Sy Harris speaking, and reminding our listeners that the young men of our nation have excellent advantages, both to themselves and in helping build America's strength by joining the National Guard, a military organization of great traditions and service.