Good morning, and welcome to this week's edition of Encompass Live. I am your host, Krista Burns, here at the Nebraska Library Commission. Encompass Live is the Commission's weekly online event. Yes, we are a webinar. You can call us that. We won't be offended. It's what we do. We host these sessions live every Wednesday morning at 10 a.m. central time, and they are recorded. So if you're unable to join us on Wednesday mornings, that's fine. You can always log on to our website and go and see all the recordings of our previous, our archive sessions of all our previous recordings. We do a mixture of things here, presentations, book reviews, mini training sessions, presentations, basically anything library-related. We want to have it on the show here. We have guest speakers that come on, and we have Nebraska Library Commission staff that do sessions, and this morning we have sort of a mixture. Once a month, we do a tech talk with Michael Sowers, who is our technology innovation librarian here at the Nebraska Library Commission. Morning. Michael's here. He's sitting right next to me here. And he brings on things that are leading more towards the techy side of things. And so I'm just going to hand over to you, Michael, to introduce who you've got on with us this morning. Thanks, Krista. So a little bit of background about how we got to today. One of the things I will readily admit I don't pay a lot of attention to directly is ILS, Integrated Library Systems. There are vendors out there that a lot of libraries use in Nebraska, so the kind of the big iron, so to speak. Then we have here in Nebraska, the Pioneer Project, which uses COHA, the open source system, which has got a whole handful of libraries in Nebraska. Using it right now, can't think of the exact number. It's well over a dozen, I'm pretty sure. And then in the Connected Project, we do Nebraska Libraries on the Web, which is hosted, WordPress hosted websites for public libraries in the state. And so our guest today, Beth Koulash, was emailing back and forth with me about setting up her library with our WordPress system. And in one of her emails, she mentioned or implied something about Linux.  And she's like, yes, I do. I use Ubuntu. And I was really happy to hear that. And then in the process of that conversation, she said, I pulled up the email here. Yeah, I developed our lightweight cataloging software on Linux last winter. And I read that email and I kind of did a double take. And I went, wait, you wrote your own ILS? And so immediately I thought, OK, this is somebody that we have to get on the show to talk about that. So, Beth, you're on the line? Yeah, good morning. All right, so yeah, go right ahead and tell us all about your project. OK, as Michael just said, we looked around at computerizing our library. And this is a very small town. We've only got 128 people actually in town and about 300 in the zip code. And the ILS is that we could find and computerize it. We're just playing monetarily out of the question for us. And we were in the process of moving our library from an old building to a modernized updated building now. And we were volunteering to help the former library director pack up the books. And she was also cataloging, you know, you know, cataloging, you know, cataloging, enjoying what we had and what was, what and what about this. And look at this and say, wait a minute, this can't be that difficult. You know, that even though I've been, you know, I've worked in software and studied it, I never worked in database design. But I'd been taught it and I could get the books out and figure it out again. So that was what I did over my Christmas holiday. And my background is I was a software engineer for a 4,500 company. I mostly worked in software quality assurance. I ran my own software company that went from everything from concept to sending out to customers and customer support. And, you know, I mostly worked in software quality assurance, but I couldn't also write code. And I eventually ended up in small town in Nebraska. And I was urged to get my provisional library certification from NLC. And level three is a result of having the degree. And so I became a director of the small town library with no computerization. And like I said earlier, the software, commercial software that we could find was completely out of the reach of the budget. And so it was pretty obvious this was a simple database application. But it kind of grew like, but it kind of grew because there were obviously some things that we needed. So the first thing we did was update cataloging materials. To be sure that we have the right kind of cross-section of materials and we're updating the catalog and weeding and adding new things as appropriate, we need to find out what we have. And the catalog should be searchable. As a kind of a side, I saw, I thought a notebook when we were moving in here, Dave, 1952, was a previous library director who had essentially done the same thing, but she didn't have the software tools available. All she had was a notebook and a numbering system and she was essentially doing what I did. And the other thing we wanted to have in there, besides being searchable, the value of the material. If a patron loses an item, what should we charge them to replace it? Or if there's a disaster, we'll lose all the part of the library to get properly insured. And the other thing is our patron privacy is of utmost importance. So some of these software things that I found, I wanted all kinds of information about your patrons, personally identifiable inspiration or the checkout and what their needs and wants are. And it was pretty clear to me that was a way to market to them, which is certainly something that highlights every concept of libraries that I've ever heard. And we certainly didn't want that. As I said earlier, the commercial cataloging software was financially out of reach for this small library. I found some freeware, but which would require you on your local server. And this is not possible in a local area either because it's, you know, we do have a very slow high speed internet connection here. And we've only had those for a few years since the Bill and Melinda Gates Foundation pretty much assisted putting it in. And as I said, I volunteered to help inventory, but we packed in the move. And doing what I was doing there was certainly not complex and I certainly have skills to do it. And then there were some considerations that we couldn't use in the applications of development software requiring royalties for government or commercial use. Or we couldn't use images or text or rely on other applications under copyright. And as Michael just said, I'm a Linux person and Linux is a free application free for any user to download and use. And there were a lot of applications available in it, some of which led themselves very nicely to assisting with software design. Which brings us to the last one here today. So we have it up. We're using it. You know, we've got almost 6,000 items in the library. And I know the other libraries have the same problem with getting a computerization as we do. So I have this lightweight solution. Now, it can probably be used for other small libraries. It's probably not appropriate for a very large library. For them, the commercial applications may be appropriate. So we have something that works well for us and so you don't have to reinvent it. So I'm distributing this to everyone who wants it for shareware. And we're just asking for a donation to reference the library group. It could be used in a small library, in a public library, in a small business library. Or even an individual with a lot of books could probably use it.  You know, this is just not an area that they can probably feel like they can make any money at. So here's what we wanted. At the very basic, we wanted a searchable card catalog. That if somebody comes in here and asks me, do you want to have any books by lowering them more? I can say, oh yes, we have this many books. And this is where they are. And information on location of material. It's kind of not appropriate to say, yeah, I know we have that, but I can't think of what it is at the moment. I may not be thinking wrong of that line at the time. And statistics of how many of what type of library we have for reading and collection development. And patron privacy is an absolute must. I fully support all of the ALAs, things of freedom to read, and freedom to not be harassed by what you're reading. And more information concerning the value of each item in the collection. If somebody loses something or it's probably ensured in case of a disaster. And these are the other things we wanted those to be nice to have, which is 24x7 online access. And the circulation system that didn't know why you don't change the book cards, the ability to place a whole lot of items, check for overdue items, notify the patrons that they have items available, that they have items that they've had a little longer than they should have. And a favorite topic. So what can this for reading? What has it been circulated? And maintain a list of items that need to be replaced. They were lost, damaged, gotten old. They were very popular when they had more than one. And here are the non-goals. Things that don't do, isn't designed to do. We didn't intend to do anything with magnetic stripes and scanners. Scanners, going down the cost quite a bit over the last few months or a year, this might be something to revisit. But as of right now, there's no intention to do anything with magnetic stripes or any kind of scanners. We didn't want to place any restrictions on hope to check out certain things. If there are things in your library that you don't want, say children to check out, like, say, animated movies, that's after the library staff and, you know, for PG movies, you know, for a little bit of information. And we didn't want to place any limits on freedom to read. And a small library is better to do a personal recognition and judgment than relying on software. We didn't want to start installing historical learning patterns or a case of any patron or calling for them for any purpose. Which is both good and bad. There were people that kind of wish we kept track of what they checked out. But as of right now, we're leaving that up to them. They can write it down any way they want. And we didn't design to make a compliant response throughout the world. You know, I designed it for my library that's in Nebraska, the United States. And if somebody else can use it, that's great. But it's not designed particularly for them. I developed it under Linux. And I used all the free tools that are available in Linux. And I used it in an industry that's really available, tools like HTML, PHP, MySQL and JavaScript. And I developed it locally, working as a volunteer. I was named director until well after I had it done. Of course, that brings up the idea of whether or not software was ever really done. And I used a great deal of free help on websites and books and forums and software developers that I know. And I borrowed some code and it was uniquely available with free use of commercial nonprofit applications where it was published, attributed to the source or attributed to the person that gave it to me knowing what I was going to use it for. The question involves coffee, diet coma, pizza and civil use books. And I got a lot of help from software engineers. I know I met through software forums in late nights. I got some help from one of my volunteers who is not a software engineer, but he told me just how I could use the, what I have already had set up for books to catalog movies and videos. That was great. So I developed it on a bunch of Linux computers using the free tools. There's a code editor there that is wonderful. And no Microsoft products were harmed in the development of this application. So how it works. Patrons are identified by the card number. Identifying information about those patrons is kept in a paper notebook and library. It cannot be hacked. The way you could get to it would be to physically break into the library, which is an issue that we can't completely solve, but it's a lot easier to identify and catch the bad guys that way. We're identifying the books by the ISBN or ASIN numbers. So they have a unique identifier. That our library has a policy of generally not to have duplicate copies of books, or if they're donated to put one of them on a book sale table. Other items like videotapes, videos and tapes and CDs. They're identified arbitrarily. And there's a password database. And privacy concerns. If only suppose that the Freedom to Read Foundation and the LA. We don't keep any information about what people with card number have checked out, what material after the material was returned. You know, as soon as they bring it back, it's checked in, the record is erased. So the only thing we keep is the date of the last checkout. That's for the, you know, for the checking it, for the evaluating it for reading candidates.  So intellectual property and copyright. And as librarians, we're all quite aware of those things. And so, you know, I developed it locally by myself and we used it where the author or the author of that code offered to be freely used in whatever credit they author wanted. And it's listed on the About page. And please, please, please read the About.html file there. There's an awful lot of information there. In fact, a good bit of what's on this webinar is, probably down there. And software that's used is part of the web host services. It's an intrinsic part of the internet, according to your browser. It's kind of hard to be using it in a lot of ways. You're not using it. If you can't use HTML or PHP, my sequel was part of the web host services. And it's been tested and worked with most computers. I tested it with various browsers and various operating systems, versions, various computer types, and various ages of computers. Some of our patrons are using some very old computers. And that's fine. And it will work with them, including it being very lightweight, very memory, you know, not memory intensive at all. People with a long amount of memory on their computer can use it. And I've got several people that put on usability of things. And there are then just patrons. They don't need to make a special trip into the library to find out if the library has a particular item, or find out what the library has on the subject of airplanes or if we have anything by Alice Miller. And we have categories for special needs items, audio books, and large type books. And ease of use. We've got menu items, input items, have a short hop attached. When you hover over them with your mouse. And even if you have a very little computer experience, you can people can pretty well search for what they want. They may need a little bit of hand holding to convince them that they can use the computer. You know, how to use a browser, how to connect to the Internet. The idea was to not make it so you had to be a software engineer or tech whiz in order to use it. I wanted to make this available to anybody who wanted to use a card catalog. And you can search for items in the library under any number of criteria. Here's an example of it. We can search for books. We can search for things like this. We can look for mysteries. We can look for humor. We can look for large print books. In the future version, I'll be able to do multiple. I guess if you want to find a large print Western, you could do there. Let's see how this is. There's very many of them. I don't have very many VHS. I feel like a few VHS tapes. This one is an old version. Let's look for a genre of humor. I'm finding that one here. That's what we have in the way of nonfiction. If you want to find, you might be able to do it. Meet General Grant. We're in the 900s. We're still working on getting a Dewey decimal system up here. One thing at a time here. And some way of the question. I'll give you an idea of how many types and genres are in the collection. And there's a user and staff version of this function. I'll show you the user version in a little bit. You can tell a potential user or realtor, somebody who's thinking about moving into the area, what you have in your library, how many volumes, what sorts of things you have. And it gives you what the collection has. And you can better ensure your loss. Some way of the question. This is all done on the server side. We can see what we have in the way of results books. Young adults and children's. This was a fairly early copy of our library's collection. It gets broken broken down like this. You've got the value of your collection for somebody who wants to insure it. And if there is a loss, the thing is that this is stored off-site at the place where the boy post is. It's unlikely that they're going to be hit by the same disaster. So we'll have the information. The insurance company says, okay, how did you come up with your library being worth $10,000? And we say, okay, we have these 1,500 items and this is how they're broken down. This is what we have over a different form of different types of books, types of materials. So now let's look available on the back end. There are user functions and there are webmaster functions. For user functions, we should all be familiar with this. You know, setting up our library website. Here we have our catalog. And this is the user version of it, the same screen. And if you do a... You don't have nearly all the functions available. One of the funs is a lot of things that a user, a patron, a curious individual shouldn't be allowed to do. We'll have to look at some of them. But in this case, they don't have any information about what it's worth. This is a real library as it stands today. We're still working on organizing everything. I still have a whole bunch of children's and young adults materials to put in. But you can see, gee, do you have any Western books? Gee, look at that. The library has any Western books. Yeah, they have. It's one of them. Or large type books. Or audio books. Different people might be interested in those things. So not anyone, I don't know. You only have a unique identifier. ISBN, ASIN, LLC, arbitrary numbers. I talked about your library. This one, this was a key. You can look for things by an arbitrary number. But the DVDs, every movie house set all up in a different way. Every publisher sets them up in a different way. So I just said arbitrary numbers in 1, 2, 3, 4. And that's perfectly fine. You need basic info like your author, your creator's name, title, and the copyright of the release date. And the age group it's targeted for. And what kind of an item it is. It's just a book, or an audio book, or a CD, or if there's a performer or a reader. And you need to decide whether or not the item can be removed from the library. That we have special collections. We have reference books. We just don't want you to move off the library. And most of it you can. And the price for the item, or the value of the item. There's a lot of ways to value it. It can be the retail cost of a new item. Or the cost shipping of a new original value. Or some other method. And if you don't enter a value it'll only set to zero. And if it succeeds it'll give you success. I'll show you how to do this. This is my sandbox. I'll let anybody play in. I'm going to enter a book that I have sitting here that was donated. My ISBN is where we're going to put this and what we're going to put it with mysteries. And we have those outside of the library. So what are we going to say about this? The Susan Henshaw Mystery. The Copyright Gade. I'll put it up in there. It's an adult book. What genre is it? It defaults to general fiction. But I'm going to say it's a mystery. What kind of a thing is it? It's making a book. It's going to read a performer. And we can usually get these things from our portfolio. So we've entered one into the database. And we can quit. Thank you for doing it. Search for it. We can find it. That's the book we just entered. We'll get to doing other things with it. We can quit the errors. We can reclassify or revalue it. We can also, in the update function, you also have an option to delete an item. And in version 1.0, it doesn't have anything in place to keep track of any items that you want to replace. So you'll have to keep track of them somehow outside of the program. And it'll display the entire database. But it can be very long if you've got even our little library and we're not even done. It has almost 6,000 items, which is going to be quite long. And you can make a backup. There are better methods than to just put it all out. Now circulation of materials. What would you want to do for me? Let's go back to the main menu. That got me a user menu. That's called what I named Alt-T. What's updated both years? We should search on it by the same things. We could do it on search. But seeing as I have the ISBN number in my Facebook, I don't know how to use it. This is the information we have. What's updated? How are we going to update it? This thing is worth a lot more money. Let's say it's worth $50 and $0.28. Let's have a reader here. We'll have George read. We'll have George read the reader for this. So it's updated. I have a lot of this computerese things. I'll get to that later. But if you give me any bug reports, I'm going to want to see that. I'm going to want to know what's in there. Let's search for the thing again. We're getting in to circulate. Which is one thing that we do a lot of in the library. You can circulate. I've actually only got the checkout date for two weeks. And it uses some things available in the database software to circulate the U.S. holidays. And the success screen for checkout is before you do date. And you can inform the pre-trainer and put a brief label on the book. Let's check out the book I just entered. I've got it checked out now. And we can go back to the main menu. I'll go into the update screen so we can see what it looks like now that it's checked out. So in version 1, renewal is a staff function. But they can contact the library staff, request them to be renewed. They can do it by telephone, by email, in person, whatever they want to do. And it's actually not renewed if it's not home by somebody else. And it'll inform you if the thing is already overdue. And whatever you want to do, post review policy. If a person has a book that's already a month overdue, you want to let them renew it. Well, I don't know. That's up to you. And holds don't expire. But you can remove a home. Let's go back to search and write books. And putting a home alone item is in here. Let's see. Oh, we'll check our own item. So we'll check it in. I don't know that you want to put a card number in for check-in. You don't have to. Even check it in. It's okay. We checked out by 333-1234. Here's the book at home. If you want to check the book out, I'll show you how that doesn't work. I'll tell you the books on hold. This other user can't check it out unless you remove the home. But maybe you've ever seen 1234 for a while. So let's remove the home. And now anybody else can check it out. And this version doesn't compute the whatever finds are available. I'll tell you that the item is overdue. And what it was due, and you can figure a fine and charge a fine according to your library policy. Or some libraries don't do fines. And some of us are in the process of reevaluating that policy. You can search for items that are overdue. Why don't we check out the other book? I want to do something with it in a bit. So here's one of our hubby screens. Once on this date, you want to hear about it. And show you the format at once in a minute. Let's say I want to hear from everything about that was due everything from the first month. I don't want to hear about anything that was due before August 1st. We'll do say we have some things that we checked out that we can contact these people. And here you will see that there's a replacement cost for them. Here y'all. You got you contact 789 and maybe tells you it's lost. The replacement cost for this is two dollars and a half. I'll get to readers and performers. We have performers on CDs and DVDs and audiobooks. That could be interesting to a person who has difficulty hearing that they might be able to understand. A man's voice better or a woman's voice better. Or there's just certain readers that they might or don't like. Somebody comes in and says, gee, I checked out that book and I left it on a bus in Albuquerque. And no chance of getting it back. Well, you look up the book, the really different database. And then you assess the cost of the patron and then put it in your list of things to replace. That's the multiple function thing. We can maybe do it on one function in another group. Another release. Okay. Here we go. Our favorite topic, weedy. Give you some assistance. It just tells you what items are not circulated. But no piece of software can tell you everything. But you probably don't want to read the non-circulating book of it. It's part of a special collection and is not available for circulation. It will just give you a list of things that just haven't circulated in some time. You might want to look at those. Like I said, we had no restrictions on what the project brought out. The intellectual freedom ideas. And here are your requirements. You need to have a website. I have a web host. It's on websites. Or possibly the government library that supports your library. The city or village or county. It must support my SQL and PHP. Most of the commercial ones do. Watch so you're not paying for things you don't need. You don't need a shopping cart or credit card payment processors. But you might still like playing the plus-cost. You choose one that provides them and just not use them. And you need to have a person to act as your webmaster. And who's your webmaster? Well, I'm not sure. Maybe somebody in your community has a blog. If they have a blog or their own website, they may be able to help you set yours up. Students or the other society members might be able to help you. Especially the computer science students. It's not incredibly hard to do at this level. You may be able to develop the skills yourself. You may be able to find somebody who hopefully would have them. Might be able to get help from the library commission. Sorry, Michael. You might be able to contract to hire one for a short time. You're used to certain tasks. And so this is all for buying for librarians. We're going to all recommend you some books. Building a website for dummies. The really, really easy step-to-step guide to building a website for absolute beginners of all ages. And building a website for free. And you can find those books online or in your library or maybe in your library alone. You need to find a web host that minimizes both my sick wall and you need to download the database. For the broadwaterftl.org.  And then there's a version to download for Windows. It will automatically download and put things in the zip folder. Please read the readme. And if you like it, please support it. All I'm asking is a $10 donation to our friends in the library group. And all that money goes to support our library. And you'll need to customize. You probably want to have your own thing. I have included my logo which is that faded picture of a bookshelf. You can search your own. Just watch for copyright on it. Take the picture yourself. Get a legally free source. A few things you want to be sure to update. I'm going to... I'm a notepad here. So let's open it. This one was downloaded earlier. You want to do a connectDB. You want to... This is your nonproperties account. This is what it is. It's a passport user. And a password in this case is password. You probably want something different than password. You have a secured password. In this case, we have secured password. You just probably know what you want. But set that up yourself. You don't want to remain. What you find... What you find in the things that you look for... You want to find a thread. And there's your database. You're putting your own library name there. In the Inetown library, our telephone number is... The telephone number. And your library's email address. Whenever you're getting your email. And you give your address... Give your address to the library. There's a message to it. I'm going to put in... This is what you remain. Hours of operation are... What do we want to say? 26. And we're done. So we save it. And here's the one we just opened. We just opened it with Google Chrome. Just to show you that... The things I put in there are really there. These are the things I put in. Sure, you have customization. You probably want to get your own live logo. You can use mine. Or just take a photo yourself. Be aware of copyrights and who owns the rights to them. That you've got a copy of it. Keep track of it. Databases don't work for databases file. Database is just a specific format. Don't get caught up in the computer ease. So this is what the schema looks like. We have a 13 character. A field for an ISBN. Can you imagine that? That we're keeping track of the holes. This is all the information we're keeping. And... It's pretty... I stripped down the basic. But privacy is guaranteed. It doesn't store anything like that. The real thing that you have to have is... The ISBN. That must be a unique key to find the item. That's how it's organized. Some of the information is required by my database, but not my SQL database. And... And I've got this file on library.sql. Which says that you can use phpMyAdmin on the waypost. If you log into cpanel, I may be getting a little bit into the techie realm here. This is part of the screen that you will see in databases. And just click on phpMyAdmin. And from there, you can run library.sql, and it will set up for you. You'll still need to set up passwords. Which can and should be unique to your site. I already said this. If you customize the details, and the logo has to be off of the... You don't want to get in the copyright, or copyright infringement, or anything like that. Then populate the database. And it's a big job. And I don't know where it would be if I didn't have volunteers. There were some people who were extremely helpful on this. And here is a few words of advice. Back up the database from the website frequently. And store multiple copies of it in multiple places. Put them on different computers. If you have a cloud storage, put one on there. And you can power them by different suns. Do that. You don't want to go through all of that work again. So the implementation is... It's 1.0 implementation. It looks good at my library. It's got some limitations. There are some things that are not yet developed. It helps that the designer of the library directs you to the same person. But there was also a disadvantage there that I had to require my volunteers to tell me they didn't understand something. And most of them were not familiar with it back in the websites. They were only using a computer and never gave them a web. And they gave me some suggestions to clarify the menus and gave me the... the help that's available on... what they wanted to know for the mouseovers and all the screens. Some of them like to have... I never meant it. We like to set the library policy in the same period. And then different home periods where you have items, have a better security system, possibly for each user, change the theme and the color and the font. Those are nice to have. This shareware with the creative commons at attribution insurance license. Please share this. You know, use it, copy it, give copies away, modify it. You don't need to encode your name with the credits for what you modified. All I ask is that you don't charge for it. Or at least not more than it costs you to make copies and mail them. And please don't commercialize it or try to sell it. And all we're asking is that you send a $10 donation to a friend in the library when you can and when you feel like you want to use it, you're comfortable doing it. And please with documentation with the about.com that appears on the website. That's how you get to it. What any page says about. A good bit of it is it tells you how to send me a bug report. And I told you about those computer-based stuff. If there's a bug in it, please give me that too. It's there. And if you have any suggestions then I'm only an entertainer. If you don't like it, tell me what you don't like and I'll see if I can modify it in the future. Because if you've got a problem or a chance there's somebody else does too. And if you install it, please register it. It's not going to put you on any mailing lists. It's not going to put you on our mailing list so we can tell you there's a new version of it. And obviously we're not going to to sell you data or anything like that. It's just for our use. And if you don't want to use it, just don't pay for it. And the little bit of legal things keep me out of hot water that we can't give you any warranty or any specific warranty or any virtuality of purpose. And I developed this with the hope of a useful hero offering it with the hope it's useful to somebody else. I can't guarantee much of anything. We're not a major software company. So we're done. Alright Beth, that was wonderful. Chris and I were sitting here just being more and more impressed every next slide and demo you got to. So Chris, do we have any questions from the audience? Yes. Yes, Beth, we had a couple of questions that are very similar. So I'm going to kind of combine them into one for you. Going back to when you're actually adding items into the database, adding the records for the books and whatnot. A couple of different questions. Can you choose multiple genres for one book? Put it in multiple categories? No, but that might be a suggestion for the future. If you have a Western romance or a funny mystery or something like that. That might be something that we could add in the future. And can new genres and formats be added to it? So can somebody add in other ones that aren't already in there by default that you created? Is that something someone could do with the software? Add in their own genres that they have at their library? You'll have to be able to write into the PHP code and the HTML code. But yes, you can add your own genre if you want it. That would be fine. We have someone who works as a volunteer at the Nature Center in a church and he's thinking that they're interested in doing something to catalog their collections and they might have other categories that aren't the same ones that you'd have in a public library, so he would want to tweak it for what they're doing. Yeah, I can see that that Nature Center probably wouldn't have a lot of books on poetry or books on American history, but they might have things on ornamental plants and food plants and things like that. But yeah, that could be customized too. And the other thing is that you would have to, after defining a particular type of you know, a letter for it and just not having any duplicates in it anyway. But if you're going to get rid of some of my some of mine because you probably don't want to have a romance in a church let's say that you could have things like Renaissance or things about people in the past Sure. Someone did ask and I'm going to actually answer the question for them how to get the software. In the show links I'm going to be including a link to where you can get the live database software that she has so when afterwards you'll have that link from the library's website from the friends and the library's website so it will be on there. Beth, I just had a couple of really quick questions and maybe one suggestion I came up with. First the comment that both had was that summary of the collection would be great for like reporting to the board, reporting to City Council, Town Council whoever funds you I could see a real use for that my suggestion based off of that was like it said we have 125 Westerns being able to click on that 125 and then getting a search result of all the Westerns that would maybe be a way you could go about it. That might be a suggestion for next time. And then the one question I had was if you would estimate for us how much time you actually put into this project or do you not want to think about it? Oh, a couple hundred hours I may be off by a factor of two or three hundred percent. Sure, okay. But you didn't do this in a weekend. I mean that's... No. Things on it grew that there were suggestions to do this and you know even on the database everybody I talked to one of the things played in a different ordering format so I said okay I just have a screen and you can start with you can order it any way you want to which is... Okay we have a question that has come in from the audience and see if I can rephrase it a little more generally a little less specific than it came through did you look at some of the existing open source products like Koho or Evergreen and why why did you decide not to go with those? I looked at Evergreen and everything I so wanted required me to have my own server and like I say if that's not really possible there would have to be someone that could maybe set the server and I'm much more willing to spend time developing software and putting it up on a professional web server than being around having somebody around and it's capable of bringing up the server with a crash 24x7 and I'll add even Koho or Evergreen which may be free up front are not necessarily free in the long run and just even ignoring cost for a library of a certain size even one of those could be overkill and it seems like what you've done gets the job done for you with your size of library like I say this is for a library like Omaha or even Scottsboro you know it's probably not appropriate for them for other libraries that can number the community they serve in the hundreds it probably is it's not it's a matter of what you want you don't need to be able to kill sure all right well Beth I will say I almost want to download this and start playing with the code I'm just not sure what I would do with it but you have intrigued me that far I'm severely impressed by the work that you've put into this and it looks like a wonderful project and I hope some of our listeners whether live or recorded will take a look at it and download it it's not like we had one or two people that were interested in possibly using it for some small projects so Beth I just want to say thank you very much for being willing to do this and share your project with us and I think at that point without any other questions from the audience we're going to go ahead and take back control for just a few minutes here and do one piece of news and then wrap up the show for the day just one thing if you look at it go ahead if you like to look at it you can go to my sandbox web-metric.com capital lot M-A-I-N HTML and that will give you a staff view of the database and it's based on an older copy of our database but you can check things out check things in, put holds on it if you mess it up too badly I can just go and hit the like key or something for those of you who missed the URL we're pulling that up now at our end we will include that in the show notes and make sure everybody can get to that so thanks Beth once again and we're going to go ahead and cover a little bit of news and do that so I just really have one bit of news that I want to mention and share at this point we've talked about 3D printers and 3D printing on the show in the past the next stage is happening and I'll just quickly pull up this brief article here from BBC News MakerBot Industries the folks who create the MakerBot printer are actually now selling for I will admit $1400 so it's not cheap I'm not buying one myself tomorrow a 3D scanner we're all familiar with the concept of scanning a piece of paper on a flat surface what if you want to scan a 3D object to then reprint a 3D object they are now starting the 3D scanners have been around this would be kind of the first one that would in theory supposing you have $1400 to spend one that's a little more available for the public to purchase and it says it takes about 12 minutes to scan a small simple object so these things are not fast these things are not necessarily cheap yet but they are coming they are now available something that theoretically you could buy for your home or for your library if you wanted to scan a 3D object for reprinting a 3D object so that's kind of my one piece of news for the month and I thought I wanted to share with everybody so I'm going to wrap up Tech Talk here and hand it back over to Krista all right great thank you thank you Michael thank you Beth that was really cool yeah it just shows the basics of an ILS are pretty simple basic the core functionality the core functionality of an ILS is you know she still says she spent hundreds of hours I mean so but at its core it doesn't necessarily need to do a lot everything past that is gravy I guess so you know just to see what you can do with it yeah alright so that will wrap us up for this morning the show has been recorded as usual so the recording will be posted up later today or tomorrow I hope you'll join us next week when our topic is the Affordable Care Act resources for libraries October 1st October 1st is the date when the healthcare marketplace goes live and libraries are where people are going to go in looking for help and assistance as they do with many things coming to us so we are going to have some resources and things available to you Mary Sowers the government information services librarian here at the library commission will be updating us on all the new things that have come up we did do a session on this in July about a month ago yeah and things have moved along definitely you know that was we were just getting and just heard about it at ALA but now there's a lot more resources and things out there that you can use so we're going to be sharing that with you so please do sign up for that it will be there will be some Nebraska specific things in there but will also be some things that are just broad for any library in the country who's trying to help their patrons get up to speed on this and get enrolled if you are a facebook user please mccompass live is on facebook so please do feel free to like us there you will get notifications of when shows are starting here is a reminder out this morning login on the fly and when the recordings are available reminders of when the next shows are coming up so if you are a big facebook user please do go ahead and like us on facebook and you'll keep up with us there then that we are done for the day thank you very much and hopefully we'll see you next time and in the future on encompass live bye bye


Welcome to lecture series on advanced geotechnical engineering and we are in module 3 and lecture 8 on compressibility and consolidation of soils, module 3 lecture 8 on compressibility and consolidation. So in this lecture we are going to discuss about the compression curves particularly under different conditions like when it is subject sample is subjected to compression and unloading that is recompression and we also discuss about what will happen when the load increment ratios are kept longer or when you have low load increment ratios and what will happen if a particular load is kept for long duration that is the effect of the secondary consolidation. And thereafter we will introduce ourselves to you know the need for the radial consolidation and then in the next lecture we will be discussing about the methods for accelerating consolidation supplements. So let us before going into the details of whatever we have just discussed, now let us see now let us look into the effect of sample disturbance on E log sigma dash curves especially for normally consolidated and war consolidated clays. So first consider normally consolidated clays and in this particular figure where void ratio versus sigma dash on the logarithmic scale is shown here and here if a normally consolidated soil that is the soil which is actually having higher water content and you know where you know this pre consolidation pressure the present effective pressure is only sigma naught dash and that is the maximum pressure whatever the soil has seen then in that case in the field what we actually see is the straight line is the virgin compression curve. Also called as field normally consolidated line or field compression curve but when we take a sample and if it is subjected to you know generally the sampling is done by using an appropriate sampler and which actually gives the least disturbance but if you have a laboratory specimen which is tested which is actually obtained with careful recovery then what we get this E log sigma dash curve is like this is indicated as the curve 2 in the figure but if the same specimen is actually remolded and reconsolidated then actually what will have is the remolded specimen will have you know this type of E log sigma dash curve. So if you look into this all 1, 2, 3 the field compression line and laboratory undistributed sample which is you know which is indicated as curve 2 that is the from the consolidated obtained from the consolidation test on a carefully recovered specimen and curve 3 which is obtained from again from consolidation test on a remolded specimen. So if you look into this at a certain stress when it actually is being subjected then all they will actually meet at a point which is the point for E naught where E naught is the initial void ratio at sigma naught dash that is the current overburden pressure. So if you look into this the difference the distinct difference between field compression curve and these laboratory undistributed sample is because of the you know the degree of disturbance what actually enters into the testing and the curve 3 which is you know if the same soil which is actually tested in 2 is say remolded and reconsolidated then what we get is this so called E log sigma dash curve which is you know in this form and where actually it appears and one more thing is that if you look into this for the remolded specimen very difficult to distinguish you know where is the you know the pre consolidation pressure. If you look into the as you go away from the you know with degree of disturbance the very difficult to distinguish its current as the stress history what the sample actually has been subjected. So in case of a normally consolidated clay what we have is that the field compression curve and you know the E log sigma dash curve for the laboratory test specimen tested with carefully on a carefully recovered specimen and you know the curve 3 which is obtained from the remolded specimen they actually meet at a point which is actually approximated as 0.4 E0 or 0.4 to E0 according to Terzegent pack 1967. Now let us see what will happen for a over consolidated clay. So as you all know that you know the soil actually has seen a pressure which is actually much more than the current present over burden pressure. So you can see that so because of this the initial portion of this curve is actually flatter and then once this stress which is actually is transferred to the soil is actually more than what it has actually seen then it will change into the you know so called normally consolidated mode again. So you can see that you know the two limbs which are actually there this is actually the portion AB and portion BC. So this for this dotted line is the field compression this dotted line BC is the virgin compression curve for the so called you know of the in the we can be obtained for the OC clay in the field and AB portion and BC portion these two are the you know two segments which will be there and the slope of this line AB is recompression index and slope of this line BC is the you know the compression index CC. Now if you are actually testing an undistribute sample the you can see that the degree of in the initial portion is flatter and then you know again it changes into the normally consolidated mode and again it meets at a point C and when the rebound actually happens for a that means there once the unloading actually happens here in the laboratory CF segment is actually is the laboratory you know unloading portion. So you can see here that the according to Schmettman 1953 he concluded that the slope of this line and the slope of this line AB are almost identical. So Schmettman 1953 he concluded that the field compression branch AB as approximately has the same slope as the laboratory unloading branch CF. So in the in case of the over consolidated clay and what we have is that you know the two segments AB and BC. So that is the reason why while discussing you know the settlements and you know we have to see the get the pre-consolidation pressure after getting the pre-consolidation pressure then you have to if you are actually having a you know if this is the field compression curve which you are adopting for the design. Suppose if this is the stress which is actually has been subjected then you have to calculate for the settlement for this portion and you have to calculate for the settlement for this portion. So that is what actually we have discussed in the previous lecture. So in this the curve one is the E log sigma dash variation for undistributed over consolidated clay in the field. So this is actually idealizing for the field conditions but if we are actually having the sample recovered from the same side same portion where actually the with a little degree of disturbance then we can see that this how what we get is that laboratory undistributed sample will yield E log sigma curve like this and then you know CF is the unloading branch and the slope of this AB and CF are found to be identical and one more thing is that CR is approximately one-fifth to the one-tenth of you know CC. So in the case of absence of data and it can be assumed that the CR the recompression index is one-fifth to one by ten of CC the CC is nothing but the compression index the slope of the normally consolidated portion. Now let us see what will happen you know if we are actually having deviations from the consolidation test and you know if the standard consolidation tests are conducted with a soil specimen having a thickness of say 25 mm or 25.4 mm in which the load on the specimen is doubled every 24 hours. This is the standard the standard consolidation test or idometer test are conducted with a soil specimen having a thickness of 25.4 mm in which the load on the specimen is doubled every 24 hours in the laboratory. So this means that the delta sigma by sigma dash is equal to one the delta sigma by sigma delta sigma is nothing but the change in load towards the initial load. So delta sigma by sigma dash is equal to one load increment ratio is always maintained as one. So the question is that what will happen if load increment ratio is greater than one what will happen if load increment ratio is less than one. So what will be the effect of any deviation from the standard procedure like if you do not keep for 24 hours if you keep for longer hours what will happen if you keep for less than 24 hours what will happen. So the striking changes in the shape of the compression time curves for one-dimensional consolidation tests are noticed if the magnitude of delta sigma by sigma dash is less than 0.25. So it has been it has been noticed that the several investigators actually have carried out and the striking changes in the shape of the compression time curves were obtained you for the one-dimensional consolidation tests if the magnitude of delta sigma by sigma dash is less than 0.25. So according to Lenard's and Altersheffel 1964 they conducted several tests on mixico-city clay with different load increment ratios and with variation of excess pore water pressure measurement with time. So conducted the several consolidation tests on mixico-city clay with different load increment ratios and variation of excess pore water pressure measurement. So in this particular slide time which is actually shown on the x axis the specimen height is actually shown here you can see that this is delta sigma by sigma dash greater than or equal to one and here delta sigma by sigma dash less than 0.25 that means that as the delta sigma by sigma. So this is equal to or the greater than one or found to be somewhat in this line and when delta sigma by sigma dash is less than one it actually migrates in this direction. So for delta sigma by sigma dash less than 0.25 the position of the end of the primary consolidation is somewhat difficult to resolve and also the C alpha by Cc the C alpha is nothing but the secondary compression index to the primary consolidation the compression index in the primary consolidation range increases with the decrease of the load increment ratio. So what we can see is that for delta sigma by sigma dash less than 0.25 the position of the end of the primary consolidation is somewhat difficult to you know resolve will not able to whether you cannot say whether it is here or here or and also it has been noted down that you can see that the distinct difference of excess pore water pressure dissipations which actually happens excess pore water pressure here is that you know delta sigma by sigma dash is actually happening less than 0.25 it is actually much before and then whereas in case of delta sigma by sigma dash greater than or equal to one it is actually happening at much later that can be understood but here you know the reduction in the early you know this position can be understood because of the low load but here what is actually happening is that here the very difficult to distinguish the so called you know the end of the primary consolidation process and another thing is that the ratio of C alpha by Cc increases with the decrease of the load increment ratio. So as we go in this direction as we go in this direction you know what will happen is that the ratio of C alpha by Cc increases C alpha by Cc that is ratio of secondary compression index to compression index increases. Now when delta sigma by sigma dash is say less than one so here void ratio and log sigma dash are plotted here and this is a case the standard E log peak curve for delta sigma by sigma dash is equal to 1 if it is less than 1 it actually will be above the you know the conventional hydrometer test result if it is greater than 1 it is actually somewhere here. So if you look into this here for a given load and more you know when you have got delta sigma by sigma dash greater than 1 so the void ratio you know decrease is high but when you have got delta sigma by sigma dash is less than 1 the percentage decrease in void ratio is low when you relatively when you compare with these two. So when delta sigma by sigma dash less than 1 the ability of individual soil particles to readjust to their position is small. So when delta sigma by sigma dash is less than 1 the ability of soil particles to readjust to their positions is very small and which results in a smaller compression compared to delta sigma by sigma dash greater than or equal to 1. So what we are actually trying to conclude from this slide is that when delta sigma by sigma dash less than 1 the ability of individual soil particles to readjust to their positions is small which results in a smaller compression compared to delta sigma by sigma dash greater than or equal to 1. So that is the reason why we actually have a distinct difference when you actually have variation of the delta sigma by sigma dash. Now what will happen let us see that the load duration suppose if you conventionally we keep 24 each load increment ratio which is actually with delta sigma by sigma dash is equal to 1 is maintained for 24 hours. So in a conventional consolidation test in which a small specimen left under a given load for about a day a certain amount of secondary consolidation takes place before the next load increment is added. So that is possible but so in this particular slide what we have actually seen is that void ratio and the sigma dash that is the log scale that is the you know the log sigma dash curve is log sigma dash axis. Now what we are actually having is that and curve A is the end of the primary consolidation load duration just sufficient for the primary consolidation. So load duration is just sufficient for the primary consolidation when you plot and this what is actually referred here in as curve A and curve B is the load duration with 24 hour load increment duration that means that this test actually conducted with 24 hour load duration. When you have more than 24 hours load duration you can see that the curve actually shifts towards when increasing load duration e log sigma dash curve actually shifts towards left side. So what we have is that you know the sigma C dash the pre-consolation pressure is also changing previously here it should be this much. So there is a shift in the pre-consolation pressure magnitude and when we actually have you know just sufficient for the end of pre-consolation you actually have different pre-consolation. So it can be noted that different values of magnitudes of pre-consolation pressure. So for soils that display secondary compression volume changes occur after the end of primary consolidation because not all soils actually express secondary consolidation. For soils that display secondary compression volume changes occur after the end of primary consolidation if each load increment is in place for a longer period. So most common for the or the normally consolidated and normally likely over consolidated soils up to OCR is equal to 2 and they are referred as the likely over consolidated soils. So if each load increment is in place for a longer period what will happen is that normally consolidated or lightly over consolidated soils they actually subjected to a certain degree of you know secondary compression and heavily over consolidated soils are less prone for the secondary compression. So because heavily over consolidated soils are less prone for the secondary compression and the shape of the curves becomes less distinct with a longer period of duration longer period in duration and it is more difficult to difficult sigma not. So with shapes of the curves they keep on changing and with longer duration it is difficult to predict it difficult to you know difficult to determine sigma not C that is the pre consolidation pressure determination is difficult here. So one if you see this actual portion here and this volume change actually occurs due to the secondary compression this volume change because that same load increment that load duration kept for a longer duration. So what will happen is that the secondary compression component is actually entering into the phenomena into the picture and it actually results in the volume change and it causes this is attributed to the secondary compression. So what we understood is that if you are actually keeping the load duration slightly for longer hours then what we actually have seeing is that there is you know certain amount of for over consolidated soils you know which is has the negligible influence because they are actually not having much of you know the secondary consolidation component will be very very low but when you have the normally consolidated soils and over consolidated soils likely over consolidated soils we have you know we can see the volume changes due to secondary compression significantly and also one more thing we have discussed is that the shape of the curves become less distinct with a longer period and duration and it is more difficult to determine pre consolidation pressure sigma dash C. Now what will happen let us say that sample thickness normally the sample thickness to diameter ratio we actually have said that diameter to thickness ratio is actually maintained as 3 basically to reduce the side wall frictions that is one of the reasons for that and the second reason is that you know to have the you know these epsilon r is equal to 0 and also to represent the one dimensional consolidation only. So for similar load increment ratios proportion of the secondary to primary compression increases with a decrease in the sample thickness. So for if you are having a for a similar load increment ratios the proportion of secondary to primary compression increases with a decrease in sample thickness and also the ratio of secondary to primary compression increases with a decrease in the load settlement ratio. Now let us see the secondary consolidation or creep effect. So in this particular slide where what we see is the E log sigma dash curve again but we have indicated here 3 curves one is curve A and curve B and there is one curve which is actually for example after 10000 years of consolidation. So in the curve A what we see is that the sedimentation is actually happening and you know this is the current war burden pressure and then you know further it is undergoing normally consolidation and the curve B is you know after 10000 years if the sample is actually subjected to 10000 years of consolidation when it is actually subjected then when it is consolidated and then what we get is this variation. So the continued secondary consolidation of a natural clay deposit has some influence on the pre consolidation pressure. So the continued secondary consolidation of a natural clay has some influence on the pre consolidation pressure sigma dash C. A clay that has recently been deposited and come to equilibrium by its own weight can be called as young and normally consolidated clay. A clay that has recently been deposited and comes to equilibrium by its own weight can be called as young and normally consolidated clay. And curve A is for young normally consolidated clay and wherein sigma C dash is equal to sigma naught dash and at E naught that is the at this particular point that is the initial world ratio and this is the curve here. If the same clay is allowed to remain undisturbed for about 10000 years and for example under the same effective under the same effective war burden pressure sigma naught dash there will be creep of secondary consolidation this will reduce the void ratio from E naught to E1 because of the creep effect the void ratio reduces from E naught to E1. Here you can see that the constant effective stress the sigma is not dash which is actually no change actually happened assume that for the 10000 years then you know the void ratio changes to E1. Now so the clay may now be called as so this clay is actually called as age normally consolidated clay. So previously if there is fresh deposition of clay is happening and the reasonably deposited and comes in equilibrium by its own weight then it is called normally young normally consolidated clay and if this you know subjected to certain amount of secondary creep and then will reduce the void ratio from E naught to E1 as shown in the slide and this clay may be now called as the age normally consolidated clay. Now the clay at E1 that is at this particular point clay at E1 now the initial void ratio for this is that E1 which is actually after 10000 years and the effective war burden pressure is sigma naught dash that is this pressure sigma naught dash and the curve looks like B and the pre-consolidation pressure when determined with the standard procedure will be sigma 1 dash. So when you do the consolidation test on this sample which is actually collected after 10000 years with the sigma 1 dash is the sigma naught dash as the you know initial war burden pressure what you look like is now that pre-consolidation pressure is actually something nothing but sigma 1 dash. So the pre-consolidation pressure when determined by standard procedure it will be sigma 1 dash. Now sigma C dash is equal to sigma 1 dash and which is greater than sigma naught dash so this is sometimes referred to as the quasi pre-consolidation effect more pronounced in the plastic place. So this type of behavior is actually more pronounced in the place of high compressibility and high plasticity that is CH type of place that is the more pronounced in the plastic place. Joram in 1972 a given estimate of the relation between the plasticity index and the ratio of the quasi pre-consolidation pressure to effective war burden pressure that is sigma dash C by sigma naught dash for the late glacial and post-glacial place. So for glacial and post-glacial place so you can see that as the plasticity index values decrease increasing there is an increase in you know ratio of quasi pre-consolidation pressure to the effective war burden pressure sigma naught dash. So with increase in plasticity index then you know this is actually more prominent and it actually increases sigma C dash by sigma naught dash which will be high. So the quasi pre-consolidation effect will be very very pronounced or the significant in plastic place. So you can see from the table which is given here that increase in the plasticity index value where the sigma C dash by sigma naught dash sigma C dash is nothing but quasi pre-consolidation pressure and sigma naught dash is nothing but effective war burden pressure. So sigma C dash and sigma naught dash which is actually they are for late glacial and post-glacial place. Now after having discussed the effect of load duration and effect of you know the load increment ratios and effect of secondary consolidation and effect of sample thickness. Now let us look into the compression curves and different forms of representation and particularly for compression and the swelling that is in the unloaded zone. So if you so if a series of load increments is applied to a specimen which is initially wet and resulting equilibrium states will appear and as shown below. So if you look into this here this specimen this is the E sigma dash that is the compression curve E sigma dash curve where you can see that the sample has been subjected to you know this curve and up to load E naught to E2 then unload it and then reload it and then you can see that you know it joins here and then it goes it get loaded further and then after here unloaded again and reloaded here. So you can see that the cyclic over-consolidated sample recompressing and cyclic this is simply over-consolidated or the swelling is also called this limb is actually called as the swelling portion that is the unloading portion that is the soil actually bounces back when the load is actually removed. So this is actually plotted on the E lag sigma dash curve when it is actually plotted you can see that this all this whatever may be the loading unloading and loading unloading cycles we have and this line joining this line this line is actually indicates the compression line which is actually obtained and close to the field compression line for normally consolidated soils. So E naught E1, E2, E3 and then unloading and reloading and unloading and reloading. So whatever the cycles we have it actually follows the that slope. So this is further indicated the outermost curve connecting the points when the specimen is in lose possible states is referred as the virgin compression line that is the this line is actually referred as the virgin compression line E naught E1, E2 is referred as virgin compression line and because it is strictly the line connecting the equilibrium states whereas equilibrium states in the sense that for that type of increment load the consolidation is completed and ending and it is strictly the line connecting the equilibrium states whereas the consolidation is a term used only for the time dependent process between any pair of. So it is also you know this is actually called as virgin compression lines because it is strictly the connecting the equilibrium states whereas virgin consolidation is something like is the consolidation is we have a time dependent process between any pair of equilibrium states. So the equation for the virgin compression line is given by E is equal to E naught minus Cz by log to the base 10 by sigma dash by sigma naught dash. So the outermost curve connecting the points when the specimen is in the lose possible states is referred to as the virgin compression line rather than as virgin consolidation line the reason is due to the fact that the line connecting the equilibrium states whereas the consolidation is the term used only for the time dependent process between any pair of equilibrium states. Now this equation of virgin compression line further represented as V in the in terms of sample volume in terms of specific volume that nothing but nu and is equal to nu naught minus lambda natural logarithm of P by P naught which is nothing but sigma by sigma naught and wherein the lambda is a characteristic constant and the nu naught is the initial specific volume. So specific volume is nothing but 1 plus E and then E is the these are actually related as the water content specific gravity and void ratio they are related this one and that. And equation of virgin compression line will be denoted as nu is equal to nu naught minus lambda natural logarithm of P by P naught and equation for swelling and recompression loop will be represented by a single straight line of the form that is nothing but nu is equal to nu naught minus kappa this kappa is the for the you know the recompression loop or the swelling loop. So which is something analogous to swelling index or recompression index natural logarithm of P by P naught where lambda and kappa are the characteristic constants for the soil and virgin compression lambda line represents the irreversible process whereas the swelling and recompression kappa lines represent the reversal process. So lambda line represents the so this is this is when you plot this line is nothing but the lambda line. So the lambda line represents the irreversible process because the soil subjected to irrequerable changes and it is actually called as irreversible process whereas the swelling and recompression kappa lines represent the reversible process. Now this is further indicated as equation for normal compression line OACD is given by E is equal to nu naught minus Cc into log sigma dash z. So here you can see that E versus sigma dash z for the consolidation compression is actually shown and this is for the one dimensional compression and this swelling. So OA and it is actually subject at O it is subjected to an effective overburden pressure of sigma naught O sigma naught sigma naught sigma naught and at point C it actually has been subjected to sigma dash y that is the it is called as the yield stress and the D is again the load was actually terminated here. So you can see that at point C you know the load you know is stopped and then gone unloaded that is called unloading and then that is called also called as the swelling line and this is called recompression line. So BA is the recompression path and then it follows the joints to C and then follows further to D. So this is again in the normal consolidation movement. So the same thing is represented in the void ratio versus log sigma dash z then what will happen is that this is the slope of the Cc that this is called as the normal compression line normal compression line and point from point A and C there at this point and A and C are at this point in the case of normally in case of log sigma dash z you will see at this particular point and B is at this point where that at the end of swelling or a unloading effect and then you know so you can see that sigma naught dash is the overburden pressure here sigma dash y is the yield stress here and so you can see here that E kappa is this particular one at this particular point where you know this recompression or the swelling was complete. So this equation for the swelling and recompression lines are given as E is equal to E kappa minus Cs into log sigma dash z and E is equal to E naught into E is equal to E naught minus Cc log sigma dash z is the normal compression line for OACD the equation for line OACD is given by E is equal to E naught minus Cc log sigma dash z and for swelling and recompression line it is actually given as you know ABC which is nothing but E kappa minus Cs log sigma dash z. Now since delta V that change in volume is equal to change in void ratio and log x to the base tan is equal to 0.43 times natural logarithm of x then we get Cc is equal to 2.3 lambda and Cs is equal to 2.3 kappa. So by using this we can actually you know once you substitute this natural logarithm into this logarithmic of base tan by using this we actually get into this particular relation they are one and the same. So for over consolidated soil at a point such as B the yield stress ratio y naught is given by y naught is equal to sigma naught dash y by sigma naught this. So for over consolidation soil for over consolidation soil that is at a point such as B the yield stress ratio y naught is given by y naught is equal to sigma naught dash y by sigma naught dash where sigma naught dash is the current stress and sigma naught dash y is the yield point which lies at the intersection of the swelling through point B and for the normal compression line. So within normal compression line that is this is so we are actually defining here the yield stress the yield stress is nothing but sigma dash y ratio of sigma dash y to sigma naught dash. Sigma naught dash y is actually obtained at this particular point and where it actually has from the normal compression line where it meets this particular first limb where the unloading unloading there which actually meets the normal compression line and that is actually is rendered as sigma dash v and which is sigma dash by v by sigma naught dash where sigma dash is the current, sigma naught dash o is the current stress and sigma dash y is the yield point at which it lies at the intersection of the swelling line through B with normal compression line. Now let us see the effect of one dimensional consolidation and swelling of soil in the ground due to deposition and erosion. So we know that deposition and erosion they are the continuous process but on the soil layer which is actually prone for you know particularly the normally consolidated and now likely over consolidated soils they are actually prone for changes because of these actions like deposition and erosion. So considering this particular slide an element soil element which is actually subjected to vertical stress sigma dash z and horizontal stress sigma dash h and when the erosion actually when the deposition happens what will happen there is a increase in the soil overburden above this particular point that it is subjected to high stress due to the so you can see that z dash B is increase here but when there is erosion takes place the stress on this actually decrease for example you can see this is the you know when the erosion takes place from here to here unloading is actually happening that is sigma dash C. This is actually indicated by as E is equal to WGS so from void ratio and now it is actually indicated with water content here and log sigma dash here you can see that AB is the you know recompression line. So the water content changes from A to B you can see that the water content decreases and the R void ratio decreases so A to B and from B that is sigma dash B when it is unloaded BC is the path which actually takes and stresses this point is sigma dash C. So here what is actually happening is that when you have K0 pressure at rest is defined as sigma horizontal stress by vertical stress when K0 is equal to 1 when it is actually having elastic equilibrium then sigma dash z is equal to sigma dash h so this is that K0 line which actually indicates so this is sigma dash h on the x axis sigma dash z on the y axis so you can see that when the case of deposition is actually happening when the deposition is actually happening you can see that that A to B it actually decreases and B to C you can see that here the K0 values are actually you know can actually go more than 1 particularly because of this stress effect. So the one dimensional consolidation in the swelling of soil ground due to deposition erosion is actually depicted and these actually you know represent the different water contents because of the type of actions which actually have been subjected. So for normally consolidated soil and likely overconsolidated soil sigma dash h is actually less than sigma dash z and K0 sigma dash h is less than sigma 0 h is less than sigma dash z sigma 0 h is less than sigma 0 z and K0 less than 1 that for normally consolidated soil where the deposition is actually happening. So this is this path which is actually shown AB here and while as heavy consolidated soil sigma h greater than sigma z and K0 greater than 1 so that is because of this here it actually can have K0 values more than 1 more than 1 can be obtained for some heavily overconsolidated soils and because of the stress locking which actually can take place because of that you know the exhibit the K0 values very high you know sometimes the K0 value can actually go up to K0 is equal to 3. So here what we are discussing is that for light and light for normally consolidated and likely overconsolidated soils sigma dash h the horizontal stress is less than vertical stress and K0 values less than 1 while for heavily overconsolidated soils sigma dash h is greater than sigma h z and K0 is actually greater than 1. So an approximation is basically often used to estimate K0 and which K0 is actually nothing but K1c where K0 of a normally consolidated clay is which is nothing but 1 – sin phi dash c and phi dash c is the critical state friction angle and root over y0 and the K1c – root over K0nc root over y0 this y0 is nothing but the yield stress ratio which we have defined earlier yield stress ratio is actually nothing but sigma dash y by sigma nought dash where sigma nought dash is the current stress and sigma dash is the stress at the point yield point which is the intersection of swelling line through b and with the normal compression line sigma dash p. Now let us see variation of water content in normally consolidated and overconsolidated soils we actually have been pointing out that for normally consolidated soils the water content will be very high and overconsolidated soils the normal content is less and so consider the variation of water content with depth for a deposit which is lightly eroded you can see that eroded that is the depth of erosion which is small or heavily eroded that is depth of erosion is very large. So we have two states this is the stress point a and b and stresses are points a and b. So this particular soil status the elements a and b actually are referring to the way the depth of erosion is relatively small and in this case the stress element c and d the depth of erosion is relatively large that means that this the element c and d is subjected to very high past pressures a and b subjected to low pressures low degree of pressures. Now what will happen is that for the likely eroded soil the difference between the water content at point a and b is relatively large while for heavily eroded soil the difference between water content and c and d is much smaller. So here what we have is that water content versus sigma dash at z is shown here. So you can see that this is the compression line loading and unloading so this first limb actually is refers to sigma dash a and this is unloading so we have done loading portion and loading portion it is simplified here and this is point b the limb point b and you can see here there is a distinct change in the water content here, here there is marked there is no negligible or marginal change in the water content with for the in this particular portion. So for the likely eroded soil the difference between water content a and b is relatively large while for heavily eroded soil the difference between the water contents at c and d is smaller. So that is what actually has been indicated here. So here if you look into this is for the normally consolidated soils are heavily likely over consolidated soils and these are the heavily over consolidated soils so you can see that the c and d so this is water content versus the depth and element a sigma dash a and sigma dash b low water contents at c and d are attributed to the very large past stresses. So the soil actually has been subjected to past stresses so the low water contents here recorded and you can see that you know this is also negligible variation but here you can see that with the depth of course there is a decrease in water content but thing is that here there is a large variation but here there is a negligible or marginal variation. So the reason is actually basically attributed to that the soil elements at c and d were actually has been subjected to very large past stresses. Now let us after having discussed these you know the effects of the load increment ratios and the duration let us look into some example problems and in this example an idometer test was performed in a clay sample of the TMM thick and drained at both sides that means that we have put kept to porous stones at top and bottom and taken from the mid-statum at the mid-depth of the clay and 70% of consolidation was attained in 6.67 minutes and what we need to find out is that time required to obtain 70% consolidation of the clay stratum and the magnitude of the settlement in that time so magnitude of the settlement in that time. So an idometer test was actually performed in a clay sample of the TMM thick and drained on both sides and taken from mid-statum depth shown and 70% of consolidation was attained in 6.67 minutes so find the time required to attain 70% consolidation of the clay stratum and magnitude of the settlement in that time. So this is you know a particular cross section a levee cross section where the sand embankment or a levee embankment is actually place and this is the clay and we have got you know 2 meter and 7 meter is the thickness of the clay and this is the element A which is E 0 is equal to 1, C C is equal to 0.2 and gamma sat is equal to 20 kilo per meter cube and here is gamma 18 kilo per meter cube water table location is somewhere here. Now the solution works out like this since the soil is same is the same clay in the laboratory and in the field and both are actually 70% consolidation. So first what we can do is that you know we can by the question of consolidation will be same because what has been done is told is that soil is same in clay in the clay in the field since the soil is same soil is the same clay in the laboratory and in the field and both are actually having 70% consolidation. So time factor T v is equal to T cv by h square so we can write it as C v is equal to T suffix v h dr square by small t and which is can be related as because C v in laboratory is equal to C v in prototype C v in field they are same so T v h dr square by T laboratory is equal to T capital v suffix v h dr square by T field they are same. So with that what we get is that T field by T laboratory is equal to h field square by h laboratory. So T field can be obtained like this T lab into hf square by hl square so we actually have measured T lab as 6.67 minutes into hf is actually given as 7 meter thick clay so we actually have said that this clay is actually having a thickness of 7 meters. So 7 divided by the thickness of the sample is 30 mm but is actually is doubly drainage so what we are doing is that 30 by 2 that is nothing but 1.5 centimeter so to equalize the units we have taken in 3 centimeter units and with this what we will actually get is that the time which actually takes place in the for 70% consolidation is about 2.76 years that is one thing which we have to note down the time in the field is you know about 2.76 years so this if this type of situations are there in the field there is a possibility that the settlement actually can affect the structure and if the settlements are actually occurring say beyond say 30 years or 40 years or so and if the design life of the structure is actually small then we need not really worry about that but if this is the situation there is actually need for understanding and eliminating these settlements otherwise the structure is actually going to be subjected to distress because of the consolidation settlements. So the amount of the settlement of the takes place for 70% consolidation can be estimated like this which is we know the degree of consolidation is nothing but 70% consolidation at let us say settlement at 70% consolidation to final consolidation settlement. So we know the final consolidation settlement expression so we use this so delta h 70% is equal to 0.7 Cc by h, h full thickness 7 meter we have to take now 1 plus E0 log P0 that is sigma 0 dash plus delta sigma dash by sigma 0 dash so the in-situ stress at mid-clear stratum before the surcharge applied we can calculate that is the effective stress we can actually calculate and delta P dash or delta sigma dash is nothing but 72 kilo Pascal's and this can be calculated as this unit weight of this which can be calculated that is the unit weight of the sand surcharge and with that is the increase in the load. So with that what we will get is that the 70% of the settles amount of settlement that takes place at 70% consolidation can be obtained as 70% of delta h which is nothing but 0.7 times Cc, Cc is nothing but 0.2 which is actually given into h which is 7 meters divided by 1 plus E0 and E0 is equal to 1 so it becomes 1 plus 1 and log to the base 10 sigma 0 dash that is the stress at this particular point is effective overburden pressure and that is nothing but 71.7 which is actually computed here plus 72 is due to this levy which is actually there. So because of that what is actually estimates is that so at the center the settlement is actually of the order of 148 mm and which actually is you know above the tolerable limit of say 50 mm so in that case you know the structure is actually going to suffer distress for example this is a then this cause you know the differential settlements for a levy and which actually can hamper with the integrity of the system. So the amount of the settlement that takes place at 70% consolidation here what we need to understand is that the degree of consolidation is determined by settlement at any time to final consolidation settlement. So settlement at 70% consolidation divided by the final consolidation settlement so because of that what we have done is that degree of consolidation is given as 0.7 for that what we have taken is that the settlement at 70% consolidation is actually obtained as 0.7 into the expression for the final consolidation settlement we have used here. So with that what we have got is that at 70% degree of consolidation what is the settlement of the particular levy at the mid stratum depth. So mid stratum that the settlement has been computed and this is actually worked out to be around 14.8 centimeters. So here also we can look into that here that if you are having if you take if you divide the clay into number of small incremental thickness let us say 1 meter, 1 meter, 1 meter then each depth each thickness if the settlement is delta 1, delta 2, delta 3 like the delta 7 then you know what we need to do is that we have to calculate what is the increase in load due to the so called the trapezium load which is there that is if you do the method of superposition I can use for this triangular load this trapezium loading and this trapezium loading then we can actually get the settlement at this particular point with that you know we may actually get the more accurate estimation of the settlement. Let us take another example where in oidometer test is actually performed on 100 meter thick specimen drained and top at bottom and it was observed that 45% consolidation the time factor was 0.15 and which was attained at 78 hours in the laboratory and we need to determine that time required to attain 70% consolidation is TV is 0.45 in a job site where the clay stratum is shown in the figure. So we have got sand layer and sand layer at the top and bottom and clay layer which is at the center here that is you know 7.5 meters thickness and let us assume that one dimensional consolidation is actually valid here and there is a building load which actually imposes certain amount of delta sigma on the soil. So this is the water table location here so what we need to find out is that we need to find out you know what is the time which actually takes in the field. So if you calculate if you see that the coefficient of consolidation is actually same for the lab and field samples again by using the same discussion whatever we had which actually says that CV is equal to TV into HDR square by T with that we can actually compute time in field and which actually works out to be the time in field is actually something like 134 years to attain 70% consolidation. So sometimes actually this appears that for a given type of clay you know that the settlements actually continues for about 134 years of time. So if you are actually constructing an important structure on that and if the clay is actually undergoing the consolidation like this and this is actually is a proof that for the you know the leading tower of PISA even after 400 to 500 years actually undergoing consolidation this is a classical example. So if you are actually having this type of situations where the settlements are actually coming predominant settlements are coming within the design life of a building then it is actually better to accelerate the consolidation settlements. So in such situations if the significant amount of consolidation settlements can occur in the design life of a structure there is a need for the acceleration accelerating the consolidation of a soil. So for that there are you know couple of methods which actually we will discuss in the next lecture. So with that what will happen is that we will be covering in this particular module the methods for accelerating the consolidation settlements.


I myself am a 24-1 RP and pretty much what that means is we are Assistant slash personal security to the chaplains when any time you're a personal secure security for anybody It's always nice to know a little more hand-to-hand combat than what you already know Make a map is near and dear to my heart now People think it's just all about getting thrown around stuff But there's more of a leadership course and learning a lot about Marine Corps history and where we all come from and stuff So on deployment, I got pretty high up in belts and I always found it interesting This is an open slot. They'd love an RP to come. I just jumped in Now that's done. I've loved it. It was great. It's great training. I just I'd hope it helped motivate sailors because a lot of them Especially our peas you think oh we're one in our job and we can't really branch out and do other things And I hope it kind of motivates them to get out there and experience other things that not only the Navy Marine Corps has to offer


This study tested the use of structure for motion, SFM, to create a high-resolution digital surface model, DSM, of a beach-dune system using unmanned aerial vehicles, UAVs. The results showed that the SFM approach was successful in producing a DSM with similar accuracy to a terrestrial laser scan, TLS, which is typically considered the gold standard for creating DSMs. Additionally, the SFM approach was found to have a lower cost than TLS, making it a viable option for creating DSMs. This article was authored by Francesco Mancini, Marco Dabbini, Mario Gatelli, and others.