Welcome to the Hindu News Analysis by Shankaraya's Academy. Displayed our list of news articles taken for today's analysis and their page numbers in different editions of the newspaper. Before we proceed to the news article discussion, as you all are aware, from 1st of May we have been discussing past year preliminary questions. That is, we are discussing some questions from Prelims 2020 question paper. So as part of today's discussion related to that, let us take few questions. Now see this question with reference to history of India considered the following pairs. They have given famous places and they are asking us to see which pairs are correctly matched. So this is a pair based question. On one side we have famous historical places and on the other side we have the state in which they are currently situated. So first let us see about Bilsa. See this is one of the towns that emerged around temples. Earlier there was a place called as Besnagar. It was an ancient city that was located on the western side of river Betua. However, if you take Bilsa it was a new town that is built after the destruction of Besnagar. And this new town was known as Baila Swamin or Billa Swamin. It was built up on the eastern bank of river Betua. This name of the place was later corrupted to Bilsa or Bilsa. Currently it is known as District Vidisha. This district is located in Madhya Pradesh. From the historical aspect, Vidisha is exceptionally rich in ancient monuments and historic places. Most importantly, near the city there are numerous remains of Buddhist Tupas or Buddhist monuments of Central India. These are commonly called as Bilsa Topes. So the given first pair is correctly matched. Next is Dora Samutra. See it is also known as Dora Samutra. It was the ancient capital of Hoishala dynasty or Hoishala Empire in the 12th century. Hoishala dynasty ruled over much of South India for a period of around 200 years. And during this time they have built spectacular temples which includes both Hindu temples and also Jain temples. Presently this is known as Halibidu and it is situated in Hasan district of Karnataka. Also it is a ruined city having a glorious past and is also popular for its Hoishala architecture. Most notable ones we can say the Ornate Hoishaleshwara temple and Kedareshwara temple. Now coming to the question, see it is an incorrect pair because it is situated in Karnataka and not in Maharashtra. Now next is Girinagar. See it is also known as Girinagar or Revathak Parvatha. It is a group of mountains in the Junaagath district of Gujarat. See the Girinagar mountain and its range is considered as older than Himalayas and therefore they are also considered sacred. So it is an important pilgrimage site for both Hindus and those who follow Jainism. So here it is correctly matched. So this is a correct pair. Therefore the correct answer for this question is option A, 1 and 3 only. Now coming to Staneswara, just know that it is adjacent to Kurukshetra and it is situated in Haryana. Staneswara is special because it is an archaeologically important site for us. So here the correct answer is option E. Now see this question with reference to jet streams and cyclones. Three statements are given. They are asking which of the statements given above are correct. Jet streams occur in the northern hemisphere only. Only some cyclones develop an eye. The temperature inside the eye of a cyclone is nearly 10 degrees Celsius lesser than that of the surroundings. So in the question first statement is about jet streams. See jet streams are a narrow belt of high altitude westerly winds in the troposphere. High altitude here corresponds to a height of above 12 km or above 12,000 meters. So they are relatively narrow bands of strong winds in the upper levels of the atmosphere. They blow from west to east. But the flow often shifts to the north and the south. See their speed varies from about 110 km per hour in summer to about 184 km per hour in the winter. We can identify a number of separate jet streams. Among these the most common or the most constant are the mid latitude jet stream or polar jet stream and the subtropical jet stream. Very importantly note that jet streams occur in both northern hemisphere and southern hemisphere. If you take the polar jet stream it forms at about 60 degrees latitude in both hemispheres while the subtropical jet stream forms at about 30 degrees in both hemispheres. So based on this knowledge if you take the first statement it is incorrect. Now the second and third statements are about eye of the cyclones. See as we know tropical cyclones are violent storms that originate over oceans in tropical areas and they move over to the coastal areas. They bring large scale destruction that is caused by violent winds. They also bring very heavy rainfall and also storm surges. And the center of such a cyclone is a calm area and this center area which is calm area is called as the eye of the storm. If you take a mature tropical cyclone it has a strong spirally circulating wind around this center. Now the diameter of the circulating system can vary between 150 kilometers and 250 kilometers and the diameter of the eye it varies from 10 to 30 kilometer. If you take this region eye it is a region that is free of clouds and it has light winds or it has subsiding air and the eye is warmer than the surrounding this fact is important. See in warm core systems the temperature inside the eye region can be higher by as much as 10 degree Celsius more than the surroundings and also note that all cyclones do not develop an eye or all cyclones do not become warm core systems. So keeping these facts in mind if you approach statement 2 and 3 we can say that statement 2 is correct but statement 3 is incorrect because the temperature inside the eye region can be higher by as much as 10 degree Celsius than the surroundings. So the correct answer for this question is option C 2 only. See this question which is with reference to social cost of carbon. The question reads which one of the following statements best describe the term social cost of carbon. It is a measure in monetary value of the long term damage done by a ton of carbon dioxide emissions in a given year requirement of fossil fuels for a country to provide goods and services to its citizens based on the burning of those fuels efforts put in by a climate refugee to adapt to live in a new place contribution of an individual person to the carbon footprint on the planet earth. First let us see what do we mean by social cost of carbon then we will attempt the question. See social cost of carbon as per the economic survey it is defined as a term that refers to the economic cost or the economic loss in the discounted value of economic welfare that is cost or induced by additional unit of carbon dioxide emissions. Simple terms we can say that it measures the present value of damages incurred when an additional ton of carbon or any other green house gases released into the atmosphere. Now this present value is expressed in monetary terms so it is an estimate of monetized damages that are associated with incremental increase in carbon emissions in a particular year. See it is the central concept for the inclusion of climate change damages in the cost benefit analysis of public policy and in public investments. So social cost of carbon can be added as a cost item for projects which induce carbon emissions and it also can be added as a benefit item for projects that induce a net reduction in carbon emissions. So therefore public projects in sectors of energy transport and agriculture should take social cost of carbon into account as they have an impact on carbon emissions. On a whole we can say that when social cost of carbon is included in environmental policy it informs the optimal carbon price and the optimal level of emissions reduction or abatement. And according to researchers the global social cost of carbon at 2010 prices for the year 2015 was 31.2 US dollar per ton carbon dioxide and it is estimated that by the year 2030 it will rise to 51.6 US dollar per ton of carbon dioxide. For India earlier the social cost of carbon is estimated at 2.9 per ton by the economic survey 2016-17. However according to recent studies based on some current prices for India it is estimated to be about 86 US dollar per ton of carbon dioxide. Just know the information. So from this discussion it is clear that the correct answer is option A long term damage done by a ton of carbon dioxide emissions in a given year. Now see this question which is about ocean mean temperature. With reference to ocean mean temperature which of the following statements are correct. They have given two statements OMT is measured up to a depth of 26 degree Celsius isotherm which is 129 meters in the southwestern Indian ocean during January march. OMT collected during January march can be used in assessing whether the amount of rainfall in monsoon will be less or more than a certain long term mean. So this question is about ocean mean temperature. It represents the heat available in the ocean layer to the depth of 26 degree Celsius isotherm. See 26 degree Celsius isotherm in the southwestern Indian ocean during January to march is seen at a depth of 59 meters. Generally they say 26 degree Celsius isotherm is seen at depth varying from 50 to 100 meters. When we say isotherm refers to a line that connects points having same temperature at a particular time or on an average over a given period. See the ocean mean temperature is estimated from tropical cyclone heat potential that was computed from satellite altimeter observations. It is one of the important climatic parameters that is required for atmospheric and oceanic studies like you can say cyclone predictions, monsoon predictions and even ocean heat transport estimations. It is relatively a new parameter for predicting whether the total amount of rainfall that India receives during monsoon season will be less or more than the long term mean which is around 887.5 millimeters. So usually we use sea surface temperature for predicting this but according to scientists ocean mean temperature has better ability to predict this than the sea surface temperature and it was found that sea surface temperature has only 60% success rate of predicting Indian summer monsoon. On the other hand if you take ocean mean temperature it has 80% success rate. So OMT is more accurate because it better represents the upper ocean thermal energy conditions and these upper ocean thermal energy conditions are mainly responsible for the summer Indian monsoon. So therefore scientists conclude that OMT has better summer monsoon predictability than sea surface temperature. In addition to this OMT also provides the required information on amount of monsoon rainfall 2 months before the southwest monsoon that is it will give such information that is required by beginning of April. This is because OMT is analyzed by measuring the ocean thermal energy during the period from January to March and India southwest monsoon sets in around June 1st each year in Kerala and note that during January to March the mean 26 degree Celsius isotherm depth in southwest Indian ocean is 59 meters. So based on these information we can say that statement 2 is correct but statement 1 is incorrect. Usually we can say 26 degree Celsius isotherm is seen at depths varying from 50 to 100 meters and not at 129 meters and specifically we can say during January to March the mean 26 degree Celsius isotherm depth in southwest Indian ocean is 59 meters. So the correct answer for this question is option B. This news article is about India's oil imports. It mentions that India imported less from organization of the petroleum exporting countries. So in this context let us see about OPEC its oil export to India and we will also see data related to India's oil demands and imports. The syllabus relevant for the analysis is highlighted here for a reference. First let us see about OPEC. See it is a permanent inter governmental organization of 13 oil exporting developing nations. It was created at the Baghdad conference of 1960 by its founding members. So we can say that the institution is 60 year old. To add another fact last year it's celebrated 60th year anniversary. Now its founding members include Iran, Iraq, Kuwait, Saudi Arabia and Venezuela. Then later several countries joined. These countries include Libya, United Arab Emirates, Algeria, Nigeria, Angola, Gabon, Equatorial Guinea and Congo. Now you can note that one important country from Middle East is not a member of OPEC. This country is Qatar. See Qatar joined OPEC in 1961 but it terminated its membership in OPEC quite recently in January 2019. So like this many countries withdraw or terminate their membership and the recent one to terminate is Ecuador. It withdrawn January 2020. So as a result of such leaving and joining if you take the number of members of this organization it is quite volatile or changing. So before the examination it is important for us to see who are the present members. Some countries have joined OPEC again for example Gabon which terminated its membership in 1995 but rejoined in 2016. Now coming to OPEC's objective it is to coordinate and unify petroleum policies among its member countries. Now why it has to be done? This is to secure fair and stable prices for petroleum producers and also to create an efficient, economic and regular supply of petroleum to the consuming nations. It also aims to provide a fair return on capital to those who are investing in this industry. Note that its headquarters is in Vienna of Austria. But we know right now the world is grappling over the pandemic that has affected everything. It also had a detrimental impact on the energy sector as well because of the measures taken by countries to curb the spread of the infection. Oil imports were drastically reduced. Therefore oil market saw a downward demand which resulted in quick filling of global oil storage. This intern has also led to large scale volatility in oil prices. So to tackle these issues OPEC and its partners they decided on a declaration of cooperation. This declaration of cooperation was an agreement to intensify collaborative efforts for restoring the market stability. Now this resulted in the largest and longest voluntary production adjustments in the history of oil market. For the first time ever through this declaration in fact member countries of OPEC even coordinated with 11 non-OPEC oil producing countries. Here the non-OPEC countries committed to a reduction in output or they committed to reduce total oil production together by almost 6 lakh barrels per day. Exactly they agreed to a total production reduction of 5,50,000 barrels per day. In fact out of this Russian federation alone committed to lowering its output by 3 lakh barrels per day. So now let us see certain data related to OPEC. See first if you take the recent available data for 2019 OPEC has around 79% of world's proven crude oil reserves. But if you see its share in world crude oil production it is just 40% and this in fact was reduced to 39% in 2019 and this is because OPEC crude oil production declined sharply in a year on year basis by around 1.86 million barrels per day that amounted to 6% decline in production. On the other hand crude oil production by non-OPEC countries they grew by 1.3 million barrels per day that is by 2.9%. Note that in 2019 top 3 crude oil producing countries were the United States, Russia and Saudi Arabia. And of this Saudi Arabia is the OPEC country. Now because of these factors OPEC's share in world crude oil exports also reduced as on 2019 world crude oil exports by OPEC amounted to 49.75%. As of 2019 world oil demand grew by 0.9% year on year and the average demand stood at 99.67 million barrels per day. The largest increases in demand were recorded for Asia and the Pacific region. Particularly by China and India this was followed by Africa and the Middle East. Here note that India is the world's third largest importer of crude oil. The first two are the USA and China. Particularly India's imports from OPEC countries were around 85% of total crude imports of India. So OPEC countries are very important if you see from crude oil import for India. However today's news says that this scenario has changed. See according to estimates in 2020 India's oil demand reduced by 10%. It even continued to decline in February 2021 also. Now why there is decline? This is because of lower demand mainly for diesel, gasoline, kerosene amidst the pandemic. Now the decline in diesel demand was because of limited demand for on-road diesel. Jet or kerosene consumption has also been negatively impacted because of lack of demand for jet fuel. This was because of reduction in international flights as well as because of the substitution with liquefied petroleum gas for kerosene in the residential sector. So this is the scenario despite improvements in economic conditions because of easing of COVID-19 restrictions in our country. But we are now facing second wave of infection. So oil demand may further reduce but contrasting to this trend OPEC predicts a different scenario as it predicts India's oil demand will increase by 13.5% in 2021. This may be because of faith on positive policy measures that will encourage private consumption and investment. And maybe also they might have thought that COVID-19 restrictions will be further eased. Now another OPEC official data is regarding India's crude imports by source. According to this, see in January 2021 Iraq remained the top crude exporter to India with a share of 19%. Saudi Arabia second with 16% share, UAE third with 13% share, USA fourth with 11% share and Nigeria fifth with 7% share. So you can see that even Nigeria is important considering our oil imports. But if you take on a whole for 2020-2021, Iraq remained India's top oil supplier. This was followed by Saudi Arabia and United Arab Emirates. Earlier, Venezuela was the fourth biggest supplier to India, but this position was taken by Nigeria and surprisingly US emerged as the fifth biggest supplier to India. In 2019-20, US was at the seventh position. You can see how these countries become important for India's oil supplies or oil imports. Now with respect to OPEC, the news article notes that India's oil imports from OPEC fell to the lowest at least two decades, which is now around 72%. This is the fact given in the article. So these are some of the crucial data regarding India's oil imports and demand and the association of OPEC countries with India and also we saw India's crude imports by source. With this information, let us move on to next article discussion. This news article is about the presidential elections in Syria that is planned to be held on 26th May 2021. As expected, President Bashar al-Assad is contesting once again. The article highlights that the number of candidates contesting in this election is limited to three. Here the role of the constitutional court of Syria is crucial. See here the constitutional court is appointed by the president himself. This court, it approves the applicants who are eligible to contest the presidential elections. In this way, the constitutional court has approved only three out of fifty one applicants to contest in the presidential elections. This measure carried out by the constitutional court has been heavily criticized saying that it has curtailed the right to contest by the Syrians. Additionally, Syria has invited lawmakers from allied countries like Russia, China, Iran and few other countries as observers in this election. However, the western members of United Nations Security Council which is led by the United States, they have rejected the outcome of this election even by now itself. So in relation to this, let us discuss a few points related to Syria's geography and polity. See Syria is located on the east coast of Mediterranean Sea in the southwestern Asia. It is bounded by Turkey in the north to the southeast and in the east we can see Iraq and in the south we can see Jordan and to the southwest of Syria we can see countries like Lebanon and Israel. See it has a relatively short coastline along the Mediterranean Sea between Turkey and Lebanon. Coming to the most important water source it is the Euphrates river and it is the only navigable river in Syria. This river it originates in Turkey then flows southeast across the eastern part of Syria. One of the important places in the region is Golan Heights. See this region was captured by Israel from Syria in the 1967 war. Later on it was annexed by Israel in the year 1981. However this move carried out by Israel is not recognized internationally. Note that in the year 2019, United States has become the first country to recognize Israeli sovereignty over this Golan Heights. Now let's come to the polity in Syria. See Syrian Republic is an independent sovereign state. It is based on the principle of rule of the people. It is a state with a Republican form of government. Also the political system of the state is based on the principle of political pluralism and democracy. Now let's relate the constitutional provisions of Syria with this news article. Syrian constitution mentions that candidacy applications for the president's election will not be accepted unless the applicant has the support of at least 35 members of parliament. And no member of parliament can support more than one candidate. Note that the term of office of president in Syria is 7 years. Here she is elected on the basis of universal, equal and direct suffrage by secret ballot. But it is alleged that the provisions given in the constitution are being diluted by the role played by the constitutional courts in the approval process. So though the constitutional provisions emphasis on rule of law, democracy and regular elections, Syria is finding it difficult to realize peace and stability. More so because of the geographical location it is in and also because of the foreign interventions and related vested interests and few other factors which could be both domestic and international. So these are some of the information with reference to the analysis of this news article. Now let's move on to next part of the discussion. This news article states that Justice Prafula Chandra has been appointed as the acting chairperson of NHRC, that is the National Human Rights Commission. See Justice Prafula is a former Supreme Court judge. He was also a member of his commission. Now he has been appointed as the acting chairperson of this NHRC. In this context let us see about NHRC, the Protection of Human Rights Act, 1993 and mainly we will see the amendments that are made to this act in the year 2019. The syllabus relevant for the analysis is highlighted here for your reference. See NHRC was established for the protection and promotion of human rights. It was set up by an act of parliament called as the Protection of Human Rights Act of 1993. So it is a statutory body. See it is an embodiment of India's concern for the promotion and protection of human rights. The commission enquires a complaint of violation of human rights or it enquires a complaint of negligence in the prevention of such violation by a public servant. It also studies treaties and international instruments on human rights and make recommendations for their effective implementation to the government. Also the commission is responsible for spreading human rights awareness among the masses and also encourages the efforts of all stakeholders in the field of human rights literacy not only at the national level but also at the global level too. So NHRC is a unique institution and the world looks at NHRC of India as a role model in promoting and monitoring effective implementation of promotion and protection of human rights. The Indian National Human Rights Commission also plays an active role in coordinating with other national human rights institutions of the world so as to enhance awareness from the perspective of human rights. It also has hosted delegations from human bodies and other national human rights institutions also from members of civil society, lawyers, political and social activists from many countries. So this is some basic about National Human Rights Commission. Now let's come to the protection of human rights amendment act of 2019. If you take the principle act that is the protection of human rights act in 1993 it was enacted to provide for constitution of NHRC state human rights commission and the human rights courts for the protection of human rights. NHRC proposed certain amendments to the act in 2019 so as to address the concerns raised at certain global platforms. In addition to this, certain state governments have also proposed for amendments to the principle act as they reported that they have been facing difficulties in finding suitable candidates to the post of chairperson of the respective state commissions because of the existing eligibility criteria in the principle act of 1993. Now in view of above issues, protection of human rights act 1993 was amended in 2019. It was reported that the proposed amendments will enable both the commission and the state commissions to be more compliant with the Paris principles in terms of autonomy, independence, pluralism and also wide ranging functions so as to effectively protect and promote human rights. If you take Paris principles see these are a set of principles defined for promotion and protection of human rights. It was given during the first international workshop on national institutions for promotion and protection of human rights held in Paris in October 1991. Now let us see some of the important amendments made to this act. See one thing is that a person who has been a judge of the Supreme Court is also now made eligible to be appointed as chairperson of the commission in addition to the person who has been the Chief Justice of India. Earlier a Chief Justice of the Supreme Court can be only appointed as the chairperson but now even a person who has been a judge of the Supreme Court can also be appointed as the chairperson. And earlier the commission consisted of a chairperson, two judicial members, one member amongst the judges of the Supreme Court, other member amongst the Chief Justice of the High Court then it had two members to be appointed from amongst persons having knowledge of or practical experience in human rights. This two members has now been increased to three members out of which at least one shall be a woman. In addition to these members there were also deemed members or deemed to be members of the commission. Earlier chairperson of national commission for minorities, national commission for scheduled cars, national commission for scheduled tribes, national commission for women. They shall be deemed to be members. However in the recent amendment included the chairperson of national commission for backward classes chairperson of national commission for protection of child rights and the Chief Commissioner for persons also to be included as deemed members of the commission. Then the amendment act aims to reduce the term of the chairperson and members of the commission and also the state commissions from five to three years and they are also be eligible for reappointment. With respect to state commissions that is the state human rights commission the amendment act provided that a person who has been a judge of a high court is also made eligible to be appointed as chairperson. In addition to the person who has been the Chief Justice of the High Court. Then the amendment act also conferred the functions relating to human rights being discharged by union territories upon the state commissions. However with respect to union territory of Delhi the functions related to human rights will be discharged by national human rights commission. These are some of the important points with reference to the analysis of this news article concerning some of the important amendments brought by the 2019 amendment act. However a very important amendment proposal was there since the coming into force of the principle law that is to make these commissions as a body whose orders are binding on the government. Right now the orders of NHRC and SHRC are not binding on the government. They are only recommendatory in nature. However on the other hand if you take information commissions central information commission or state information commission according to section nineteen seven of the right to information act their orders are binding on the public authority. However many human rights defenders they point to the fact that the 2019 amendment act did not take into consideration of this very important crucial proposal so as to make these commissions whose orders must be binding. Right now it is only recommendatory in nature. Now let's move on to next part of the discussion. This discussion is based on this editorial article that talks about the nuclear relations between the United States and the North Korea. In this discussion about the tensions between U.S. and North Korea over this matter the possible approaches to arrive at a common ground among these two and also the way forward. The syllabus relevant for the analysis is highlighted here for your reference. See as per reports North Korea is reportedly have made rapid progress in its weapons program. It is said to have active and increasingly sophisticated nuclear weapons and also ballistic missiles. In addition to this it is also believed that it possesses chemical and biological weapons and even after years of heavy sanctions imposed on it for its nuclear measures North Korea continues to practice its weapon activities. Now coming to recent times just days before the inauguration of U.S. President North Korea disclosed a new type of submarine launched ballistic missile at a military showcase. It declared this particular ballistic missile to be the world's most powerful weapon. Also know that the supreme leader of North Korea has pledged to expand the nuclear arsenal of North Korea and its military potential by outlining a list of desired weapons. These weapons include long range ballistic missiles and super large warheads. So in this bad drop the new U.S. President Biden in his recent address to a joint session of the Congress remarked about the North Korea's nuclear policy. He said that the Iran and North Korea's nuclear programs they present a serious threat to the security of both United States and also the security of the world. He further ensured to address these threats through diplomacy and also through stern deterrence. As a response to these observations made by Biden North Korea accused that Biden's administration is being hostile to North Korea. However if you come to approaches after reviewing the U.S. policy towards North Korea the present U.S. President is likely to adopt a strategy somewhere between Barack Obama and Donald Trump. If you take Barack Obama he followed the policy of strategic patience whereas Donald Trump practiced or focused in conducting a top level summit between the two countries in dealing with the nuclear challenge. Because Mr. Donald Trump did strive for achieving a single sweeping deal with King Jong-un. Whereas former President Barack Obama followed strategic patience where he sought to compel the North Korea to come for negotiations and how it will come for negotiations by imposing sanctions and by imposing other forms of pressure. But both approaches have failed and North Korea is keeping on expanding its nuclear arsenal and other arsenal and this has made North Korea to remain as an unresolved foreign policy puzzle for the U.S. Government. However Biden's approach as per the words of White House Press Secretary is to have a careful practical approach that is open to diplomacy with North Korea. It will also try to make practical progress that increases the security of United States and its allies. Now let's come to possibilities present possibilities how to deal with North Korea. See after Mr. Biden assumed office North Korea conducted short range missile tests and this was viewed by the United States as a kind of provocation and it is reported that after carefully studying the scenario Mr. Biden do not have many good options in dealing with North Korea. If you see the main goal of viewers in North Eastern Asia is denuclearization of Korean Peninsula and many report that the only possible way to achieve this is by diplomacy that is by having discussions negotiations with North Korea. This is because if you go with a military strike on North Korea it will not be considered as a clever decision because North Korea is a nuclear weapon state if it retaliates it will be a catastrophe for the entire world. Now in terms of Trump Kim summit one good aspect is that even though they did not lead to any success or development it created a diplomatic momentum for engagement and North Korea though it issues threats to expand its nuclear program it sticks to self-imposed moratorium or temporary prohibition on nuclear tests and long-range ballistic missile tests in the current scenario. So these two positive measures on one side we can also find a situation in North Korea where it is going to a tough economic crisis even its supreme leader King Jong himself admitted that his five year economic plan for the country failed to meet targets in almost every sector and mainly this is because North Korea closed its borders in last January that is in 2020 to prevent the spread of COVID-19 and this has separated it mainly from its neighbor and ally China as a result in fact the trade between North Korea and China dropped by about 80% in addition to this typhoons and floods have also devastated homes and crops in North Korea and then North Korea faces strict international sanctions including the sanctions over its nuclear program all these aspects together have led to the deterioration of North Korean economy so to conclude this is the right time for Mr. Biden to make use of this opportunity so as to arrive at a common ground with Mr. King on one side he can talk about denuclearization with North Korea on the other side he can extend help with respect to removing sanctions or solving economic worries of North Korea this could be considered as new North Korean strategy which should be the focus of Biden's administration that is what is the crux of the article so these are some of the information with reference to the analysis of this editorial in the discussion we saw about the tensions between U.S. and North Korea and the nuclear sphere the possible approaches the approach of Barack Obama the strategic passions the top level summitry of Donald Trump then what are the challenges currently faced by North Korea in this COVID-19 world in this world that faces COVID-19 as a dangerous threat then we saw what could be new North Korean strategy of U.S. government now let's move on to next part of the discussion this news article talks about purchasing manager's index first let us see about the index and then we will discuss the article see purchasing manager's index is a survey based economic indicator it is designed to provide a timely insight into business conditions this index is widely used to anticipate changing economic trends in official data like the GDP it is also used as an alternative measure to the official data about the country's economic performance and business conditions see the PMI data are used by financial and corporate professionals to better understand where economies and markets are headed to and it helps them to uncover or to explore various opportunities see this index it is compiled and produced globally by a company called as IHS market this index is produced for more than 40 economies worldwide including India know that originally purchasing manager's index was compiled for manufacturing sector only later it was extended to include other sectors like services construction and retail today's focus is manufacturing purchases managing index it is a survey based economic indicator that is designed to provide a timely insight into changing business conditions in the goods producing sector that is the key point it is the weighted average of 5 indices which are new orders output, employment suppliers, delivery times and inventories of goods purchases so based on the data by purchasing manager's index or the manufacturing PMI we can assess India's manufacturing sector activity now the news is regarding India's manufacturing PMI for April 2021 it was at 55.5 see if the index is more than 50 that means there is good improvement over the previous month and since the number is 55.5 it is said that there is a solid improvement in the health of manufacturing sector and among the categories in the sector consumer goods was the strongest performing category this was followed by capital goods and then intermediate goods if you take the reading for the month of March 2021 it was again 55.4 that meant there is again a solid improvement compared to the previous month any number above means expansion as per the manufacturing PMI released by IHS market then with reference to India the output index and new orders index also expanded for April 2021 but this expansion was the slowest in 8 months the reason for expansion was due to pickup in demand and marketing efforts but the slowest expansion in output index and new orders index is because of surging COVID cases in the country so these are some of the information with reference to the analysis of this news article wherein we discussed about manufacturing purchasing managers index released by IHS market and how to assess for a particular economy wherein we saw India's performance in April 2021 now let's move on to next part of the discussion this news article talks about the decision of Manipur High Court see the Manipur High Court allowed seven nationals of Myanmar to travel to New Delhi so as to seek protection from United Nations Refugee Agency that is the commissioner for refugees the decision was arrived as though India is not a party to UN Refugee Convention it is still a party to international human rights standards such as universal declaration of human rights then international covenant on civil and political rights High Court also stated that the important and extreme protection afforded by article 21 is available to citizens and also to non-citizens and it also encompasses the right of non-refoulement that is you should not force a refugee or asylum seeker back to the country or a place wherein they are liable to be subjected to persecution which means as we know the situation in Myanmar is now in the hands of military hunda if these seven nationals are asked to go to Myanmar they may face persecution there so they should not be returned there so that is the right of non-refoulement or the principle of non-refoulement so in this regard let us see about the UN Refugee Agency which is UNHCR which has its headquarters at Geneva in Switzerland see United Nations High Commissioner for Refugees is a global organization whose primary purpose is to safeguard the rights and well-being of those people who have been forced to flee obviously these include refugees, returnies people who are considered stateless and those people who are displaced internally and also asylum seekers see UN High Commissioner for Refugees was first created in the year 1950 during the aftermath of second world war the purpose was to help millions of Europeans who had fled or lost their homes in the last decade that is during the second world war so coming to the key legal elements that form the basis of this agency it is the refugee convention and the 1967 protocol associated with this refugee convention right of non-refoulement forms the core principle of these agreements and remember India is not a signatory to this 1951 refugee convention or to its 1967 protocol and India is alleged by some countries and some human rights defenders as not having a national refugee protection framework in consonance with international refugee rights standards or in consonance with international refugee rights standards now let's come to the governance of this UN Refugee Agency see UN High Commissioner for Refugees is governed by UN General Assembly and the UN Economic and Social Council the executive committee of UNHCR it approves the agency's biennial programs and the corresponding budget and these are presented by the High Commissioner who is appointed by UN General Assembly for that it is the High Commissioner who is responsible for direction and control of this agency and she or he will be directing the agency's work with the assistance of Deputy High Commissioner and Assistant High Commissioner for the protection and operations now coming to the funds of this agency see these are mostly voluntary contribution 86% of the funds come from governments and the European Union 3% come from other intergovernmental organizations and pooled funding mechanisms 10% of the fund comes from private sector this includes funds that are coming from foundations, corporations and also the public note this point that the agency receives funding from the private sector also they also receive a limited subsidy of 1% from UN budget for their administrative costs and they also accept in kind contributions like taking items like tins, aids like medicines and trucks they also work with other sister UN agencies whose work complements or converges with this UN refugee agency some of the agencies who are considered as partner agencies of UN refugee agencies world food program UNICEF WHO UN development program office for the coordination of humanitarian affairs then UN High Commissioner for Human Rights and also the joint UN program on HIV or AIDS or UN AIDS so these are some of the important points with reference to the analysis of this news article through which we discussed about UN refugee agency which is also called as UN High Commissioner for Refugees now let's move on to next part of the discussion we have come to the last session the practice questions discussion session see this question consider the following statements with respect to the two organizations organization of the petroleum exporting countries and Asia Pacific economic cooperation 3 statements are given they are asking if the statements given above are correct first statement OPEC is a subsidiary organization of APEC the statement is incorrect there is no relation between OPEC and APEC OPEC is an organization of oil exporting nations but APEC is a regional economic forum it was established in 1989 so as to leverage the growing interdependence of the Asia Pacific APEC that is the Asia Pacific economic cooperation aims to create greater prosperity for the people of Asia Pacific region by promoting balanced, inclusive, sustainable innovative and secure growth and also by accelerating regional economic integration so first statement is incorrect see the second statement all the members of APEC are members of OPEC this again is also incorrect if you see currently not even one member of Asia Pacific economic cooperation is a member of organization of petroleum exporting countries OPEC has 13 members and APEC has 21 members third statement India is a member of neither organizations that means India is not a member of both these organizations this statement is correct so third statement is the only correct statement therefore the correct answer is option C3 only see this question with reference to UNHCR three statements are given they are asking which of the statements given above are correct the office of the United Nations High Commissioner for Refugees serves as the guardian of the refugee convention and its 1967 protocol this statement is correct the convention expressly provides that states are expected to cooperate with UNHCR in ensuring that the rights of refugees are respected and protected see statement two India has a signatory of 1951 refugee convention and its 1967 protocol relating to the status of refugees this statement is incorrect because India is not a signatory of 1951 refugee convention or its 1967 protocol third statement the cornerstone of 1951 convention is the principle of non-refoulement this statement is correct it is mentioned in article 33 of this 1951 convention according to this principle a refugee should not be returned to a country where she or he faces serious threats to her or his life or freedom so first and third statements are correct so the correct answer is option C one and three only which one of the following countries of India does not open out to Mediterranean Sea Syria, Jordan, Lebanon Israel you can find that Syria, Lebanon and Israel they border Mediterranean Sea or they open out to Mediterranean Sea Jordan that does not open out to Mediterranean Sea correct answer option B see this question with reference to purchasing managers index which of the following statements is are not correct with reference to purchasing managers index often seen in news which timely insight into changing business conditions and the goods producing sector see this statement is correct it is compiled and released by world bank see this statement is incorrect see at a global level for around 40 economies including India this is being released and it is compiled and released by IHS market there are some national PMI surveys that are released but these are released by say for US it is released by institute for supply management for Denmark it is released by Danish purchasing and logistics forum for Canada it is released by highway business school for Singapore it is released by SIPMM institute which is the educational arm of Singapore institute of purchasing and materials management so these are all on the national basis at the global level we have the purchasing managers index released by IHS market coming to statement 3 it is released only for the manufacturing sector now this statement is incorrect originally IHS market compiled and released PMI for manufacturing sector only but later it was extended to include other sectors such as services construction and retail also the first statement is correct because it does not say only here the question asks for incorrect statements therefore correct answer is option D 2 and 3 only are incorrect main questions are given for practicing you may write the answer and post them in the comment section for peer review with this we come to the end of today's analysis if you like the video click the like button comment share the resource among those who are in need of such resources and subscribe to Shankaray's academy for more updates and content on civil service exam preparation


Welcome to advanced geotechnical engineering course, we are in module 5 which is on stability of slopes and this is lecture number 6 in stability of slopes and in this particular lecture we are going to concentrate on slope stabilization methods. In the previous lecture we have discussed about different slope stabilization techniques and in continuation of our discussion we will try to discuss about how lime piles or lime slurry injection can be helpful in enhancing the stability of a slope is a type of chemical hardening which we have mentioned in the previous lecture. Then the another method which is for in situ slope stabilization is soil nailing, so that we will try to discuss in detail and finally we will look into the method which is called as biotechnical stabilization or biotechnical slope stabilization which is gaining momentum in the recent past with a requirement of eco-friendly awareness. Before going into the typical slope stabilization techniques for natural slopes as we discussed there are two types of slopes, one is natural slope and other one is say manmade slopes and embankments fall in the manmade slopes category and in this particular slide the typical embankment failures are shown, the first figure on the left most left corner is the rotational failure of an embankment which is actually shown and this is possible when there is underlying clay is soft in nature then the direction of the movement is vertical and then outwards in this direction. So this is actually also called as a base failure which is actually happens if you are having a underlying soil which is soft in nature. Then the another failure of the typical embankment is that there is a displacement failure where embankment portion settles down with maximum settlement at the center and heaving on the both the sides. So this is typical nature for the soft material and where actually if it is a hard material is here nearby to the bottom surface then you can actually have settlement and a heave which is actually takes place on the both the directions. Suppose if there is an underlying layer is a soft clay seam beneath the soil surface and there is a possibility that a translatory failure can actually happen. To avoid these embankment failures one of the popular alternative is to stabilize the manmade slope or embankment slope by constructing a berm or in a combination of you know stabilizing with stone columns or so. So the effect of the berm on the slope stabilization if you look into is in this particular slide where an embankment which is subjected to a failure a base failure or rotational failure with a circular arc L1 with the center of arc O1 is shown here and which yields a say factor of safety FS1 then by the providing a berm the center of the arc shifts to O2 and the radius of the arc becomes say R2. So which yields a factor of safety FS2 which yields which is more than the FS1. So the provision of the berm helps in enhancing the stability of a slope. So the question is that you know the extent of the horizontal extent of the berm from the toe of the slope that is important and the height of the berm which is required need to be a set time. So sometimes what will happen is that it is not possible to extend the berm up to you know large distances in such situations one can actually resort to adopting you know the yesterday lecture the previous day lecture in the previous lecture we discussed about slope stabilization using stone columns that can be combined along with this are incorporated into it. So in the next slide what we are going to do is that the slope stabilization using stone columns which is particular method which is used for installing these rammed pierce or it also called as stone columns and in case there is a slope is existing and then the bund is required to be constructed on that the additional with the widening of the bund is required here then what we do is that we drive the sheet pile wall from the top. So this is in this particular slide a typical installation of stone column is shown here wherein the borehole which is actually made of required diameter and the stone charge is actually feed it. So there are two different types of feeding techniques one is called top feeding technique other one is called bottom feeding technique. In the top feeding technique once the borehole reaches to the certain depth then the charge is actually feed it in installments and then it is compacted by using the same are rammed by using this boiler. So this technique nowadays the availability of the vibrofloat sender helps to compact these stone charge efficiently and also helps in constructing the stone columns efficiently. So this is a particular technique where the slope stabilization of a existing embankments can be enhanced or an embankment to be constructed on a soft soil can be enhanced by using this particular technique. Now as we discussed that there is another technique which is called slope stabilization enhancement basically by using lime slurry injection or lime columns. Notice the lime and fly ash injection is also getting popular because of the abundant availability of the fly ash the appropriate combination of lime and fly ash are being used. So this slope stability can be improved by injection of lime slurry to increase the shear strength of clay and silty soils and it is not much successful with the sandy soils. The slope stability can be improved by injection of lime or lime fly ash in appropriate combinations in the form of slurry to increase the shear strength of the clay and silty soils and this is also sometimes is done in the form of lime columns or lime piles wherein similar to stone columns a drilled hole is filled with a lime of an appropriate type of material which is specified in the specified and this is actually done basically by a rotating disc auger penetrates into the depth of to a slip surface or sometimes beyond the slip surface and the stabilizing agent is injected into the resulting into the needed lime columns and one demerit of this method is that at least 80 days must be must elapse before columns of the stabilized soil can be subjected to loading but however the rate of increase of the strength over a period of time was found to be increasing because of the mobilization of the reactions which actually takes place with the presence of the lime. So this though this method actually has got at least the requirement of 80 days is required to before you know the stabilized soil is actually subjected to loading. So in this particular slide the installation of lime column or lime piles is actually shown here where a 0.5 meter to 0.8 meter diameter hole is actually made and they can be used up to 15 meter length according to Brahms 1991 and where the drilled hole is actually filled with the help of this lime column machine and is feeded and the lime is actually feeded and the lime columns are actually constructed and this is a typical you know slope stabilization by using injected lime slurry shown and nowadays with the availability of the portable rigs there is a possibility that it can be mounted easily on the slope surface and the injection is actually given along the slope surface. So this is particularly for you know wherever when we have highway railway embankments which are actually constructed you know with lime and posing problems because of the swelling and shrinking cycles and in such type of cases the adoption of this technique seems to be promising. However in the field the injection of the lime has to be done with an appropriate selecting the appropriate pressure and in appropriate quality of the lime. So this is a typical slope stabilization using lime piles which is actually shown here in this particular slide where you know the stabilization is actually adopted for a clay soil the approximate lime limit of treatment is actually shown here. So in this one then the portion is actually you know improved with by installing lime columns. So the increase in the soil shear strength due to lime columns can be expressed estimating the average shear strength along a potential failure or rupture surface in the soil. So this is actually obtained as C average is equal to Cu into 1 – A plus S column by A. So here what is actually Cu is the averaged cohesion. So Cu is the average undrained cohesion of the soil which is you know of the untreated and unstable soil and S column is the average shear strength of stabilized clay within lime piles and suppose if the columns are arranged in say square pattern and then let us say at S be the spacing of these lime piles then the soil in between which is that the gain instant that is average shear strength of stabilized clay within lime piles is treated as S column divided by A, A is nothing but the relative column area the column area which is nothing but pi D square divided by 4 square where it is nothing but pi D square by 4 is nothing but the area of the single lime pile divided by S square is nothing but the area some covered by this lime piles that S is the center to center spacing of lime columns or lime piles and D is the diameter of the lime column or lime pile. This S column is basically is a function of overburden pressure and relative stiffness of lime piles with respect to the surrounding unstable soil. So S column is found to be reported by Brahms 1991 as a function of overburden pressure and relative stiffness of lime piles with respect to the surrounding unstable soil. So with this once we get the average strength over a period of time let us say after elapsing certain time after the installation and this can be used for you know arriving at the enhanced effect on the increase in the stability of a slope. So lime treatment as a mix in place technique has been widely and successfully used around the world to improve weak soils and novel techniques using lime are now being developed and also to add to this you know some modern materials like nano materials and which may be helpful in enhancing the performance and this use of lime piles particularly if you are having a requirement of for the short term requirement which is not a long term stability of a slope but for a certain period of time and for stabilizing shallow slopes and use of lime piles seems to be very promising. And recent research has investigated the reaction mechanisms associated with the lime pile stabilization however with the current standard the further work is actually warranted in this direction to understand and quantify about the slope stabilization using lime piles. So then we actually have said that the another technique which is can be used for enhancing the stability of a slope or an excavation is by soil nailing technique and this is a technique which is gaining popularity for the past four decades and the soil nailing technique is a technique basically in which the slopes excavations are retaining walls are passively reinforced by insertion of relatively slender elements. These slender elements are nothing but normally steel reinforcement bars and they are passive anchors in which you know these nails are not prestested and they are actually soil nails which are called as soil nails and dowels and rock bolts and this technique also you know in a light way it is used in stabilizing the rock slopes also and these nails are actually placed along the slope surface again in the you know two different patterns one is the square pattern where with SH is the horizontal spacing between the nails and SV is the vertical spacing and the length of the nail which is actually to be penetrated into the ground to be inserted into the ground is recommended in the range of 0.5 to 0.7 h where h is the height of the slope to be treated and this technique is very useful particularly when we are actually using you know when suppose if you are having an abutment beneath the bridge and the road widening needs to be taken place and previously the abutment is with say natural slope and when you wanted to widen the road then there is a requirement of the steepening of the slope in such situation there is a need for enhancing this by using this you know the soil nailing technique. So in this particular slide this are the you know reinforcing bars typically shown and the different types of nails are there which we are going to discuss suppose if this is the potential failure surface and this is a portion which is called as a stable ground or this is say active ground or actual or potential landslide zone. So what will happen is that the relative movements mobilizes axial stiffness and resistance of dowel or soil nail and increase the normal stresses on the failure surface and basically it enables you know mechanism which actually enables the develops the resistance against the failure and the shear resistance of the dowel or a nail transfers demand to the underlying stata that is in the stable ground and increase in normal stress on failure surface increases the available resistance. So here increase in the normal stress at this particular portion enables to increase the resistance to the failure along the shear surface in addition to this is actually in addition to the resistance offered by the soil. So in the soil nailing technique basically they are passive anchors and they are inserted in the form of with their slender elements they normally steel reinforcing bars and these are done with a certain layout what is called as a nail layout and also their space that they are you know inclined at a certain inclination and they also been provided with certain facing which we are going to discuss. So here the slope stabilization using soil nailing technique wherein this is basically a top down construction technique wherein in fact this is actually very useful for temporary shoring purposes in underground excavations like suppose if you are actually excavating a certain ground in a soil slope area so excavate the level one and then the next method is to you know provide a short creating on the surface and then drive the nail or you know install the nail and then you know excavate further so like that one actually can do the installation of this nails from nail one, nail two, nail three, nail four, nail five, nail six from nail up to bottom of the other toe of the slope in this fashion and this is a typical you know installation of nail by using you know a specific rig which is actually used in the field is actually shown here. So the slope stabilization using soil nailing technique basically a top down construction technique and as we have discussed the nails are not pre-stressed they are basically called as passive elements which actually are used for stabilizing the slopes or excavation phases and the depending upon the requirement so there can be some cut element of the length of the nails also can be done but this is that 0.5 to 0.7 h the horizontal minimum required and this is the vertical spacing of these nails and along this slope surface the horizontal spacing will be there and this is the facing element which is required and there is at this portion where the nail is actually is bolted so that is where actually here the head of the nail will come into picture and the nails are actually inclined generally up to 15 to 20 degrees but however this depends upon the back slope inclination and also this depends upon the slope inclination for which this nailing technique is used. So various types of the soil nails in the sense that two popular types are driven nail and grout and nail in the grout and nail the after excavation the first holes are drilled in the wall or slope face and then in the nails are placed in the pre-drilled holes. Finally the drill hole is filled with cement grout so in this portion the entire length of the nail is actually filled with cement grout so the placement of this cement grout also helps in bonding the nail grout surface with the surrounding soil efficiently. So in the grout and nail after excavation the first holes are drilled in walls and slope face and then the nails are placed in pre-drilled holes at a particular inclination. Generally there are two types of placement of this grout and nails one is grouting one is gravity driven grouting wherein the grout is allowed to flow with natural gravity the other one is the pressure driven installation of the grout. So nowadays with the current research actually shows that the pressure driven grout found to be efficient because of the increased you know participation of the surrounding soil in mobilizing the soil nail grout resisting shear stress. The driven nails in this state the nails are mechanically driven into the wall during excavation and installation of this type of nail soil nailing is very fast the sense that the nails are placed at the nail bars are actually fired into the soil however it does not provide a good corrosion protection and this is generally used for temporary nailing for example wherein we need you know some immediate remediation measure and then these driven nails can be used very very effectively. And self-drilling soil nails in the sense that hollow bars are driven and grout is injected through the hollow bars simultaneously during drilling. So this method is faster than the grouted nailing and it exhibits more corrosion protection than the driven nails. Grouted soil nail basically here Z grouting is used to erode the ground basically the presence of water jets and air jets will allow the creation of a sort of erosion at the tip where this is done and for creating the hole into the install steel bars and the grout provides a corrosion protection from for the nail. The launched soil nails are bars are launched into the soil with very high speed that is what actually is called firing of the nails involving composite air and this method of installation very fast however it is difficult to control the length of the bars penetrating into the ground. So depending upon the soil resistance so launching soil nails the other one is the driven nails so that popular types of nails are grouted nails and driven nails and the as far as the type of installation of grout is concerned the jet grouted soil nail is another type and other one is called self drilling soil nail where hollow bars are driven and the grout is injected through the hollow bars simultaneously during drilling. So as we have discussed that there are two you know zones for the soil nail system wherein we have here active zone and then passive zone. So with the movements which are actually happening in the slope in the active zone the nail mobledges resistance in the form of tension as well as the shear and bending. So the slope which actually is you know reinforced with soil nailing resist tensile stresses shear stresses and bending moments imposed by the slope movements in the process what will happen is that the slope will get the enhanced stability and possibility of occurring or attaining steep slopes can be achieved can be obtained. So here it also depends upon the resistance offered or the bearing stress offered by the facing at the nail head that is this portion which is actually shown here. So and then the shear stresses which are actually mobilized at this area also you know corroborate for the functioning of this soil nail system. So this is in this slide the schematic distribution of tensile forces along soil nails are shown here and it is shown here the tension is mobilized along the nail length like this and almost 0 at the facing and 0 at the other end of the nail and this is the you know potential failure surface and this is the line of the maximum soil nail tensile forces and the force is supposed to be maximum distribution magnitude will be high here and as we go come to the top the mobilization of the nail in tensile forces will be less here but if the length is not adequate beyond the active zone area there is a possibility that the nail is actually subjected to a float failure. So in this one of the checks is to also to do a institute float test to ascertain the float capacity of these nails with that the nail capacity can be ascertain and another possibility is that the once the soil nails are installed and there is a can be clubbed with an instrumentation so with that the monitoring of this soil nail wall system can be or soil layered slope system can be achieved. So before looking into that the potential failure modes of a you know soil nail system can be seen there are basically two types one is called external failure and internal failure the external failure refers to the development of the potential failure surface essentially outside the soil nail ground mass. So and the failure can be in the form of sliding that means that entire soil nail block including the up to that means that up to which the length the nails were installed the sliding can take place and rotation are bearing particularly if the ground which is housing this particular structure say is not having adequate bearing capacity that bearing failure can occur or other forms of loss of over stability. So external failure basically refers to potential failure surface essentially outside the soil nail ground surface and the failure can be in the form of sliding rotation or bearing or other forms of overall or global stability. The internal failure refers to failures within the soil layer ground mass so that means that it can be you know breaking of the nails or breaking of the nail head and within the active zone basically the inter failures occurs within the active zone and passive zone basically occurs in the form of a pull out it takes place or in both of the two zones of the nail system. So internal failure can actually happen in active zone as well as in passive zone that is passive zone or the stable zone beneath the active zone so in both the or in both the zones of a soil nail system. So in the active zone basically the internal failure mode include the failure of the ground mass that means that the ground disintegrates and flows around the soil nails and the soil nail heads and the other thing is that bearing failure underneath the soil nail heads that means that if the facing is not having adequate you know load carrying capacity then there is a bearing failure can occur and the structural failure of the soil nail under combined actions of tension shear and bending that means that the structural failure of this so the adequate if the structural capacity of the soil nail is inadequate then the structural failure of the soil nail can occur under combined action of tension shear and bending and structural failure of the soil nail head are facing the bending or punching failure can actually occur or failure at the head reinforcement or facing reinforcement connection and surface failure between soil nail heads wash out erosion or local sliding failure there can be happen because of the when seeping of water the local failures can actually often erosion and local sliding failure in the passive zone basically the zone beneath behind the active zone the pull out failure at ground grout interface possibly this occurs at the top surface of the slope or wall and of the grout reinforcement remains basically should be considered. So in this particular slide what we have seen is that in the active zone the internal failure modes include failure of the ground mass basically and the bearing failure underneath the soil heads and the structural failure of the soil nail under combined actions of tension shear and bending and the structural failure of the soil nail head and the surface failure between soil nail heads and another in the passive zone what we said is that the pull out failure at the grout ground interface or grout reinforcement interface that means that if the reinforcement bar is pulled out of the grout surface that also can occur within the soil nail or a pull out failure can also occur between the grout and ground surface also. So two modes of failures can actually be possible when we are actually having a failure in the passive zone as far as the pull out failure is concerned. So here whatever we have discussed is shown pictorially this is the potential internal failure modes of a soil nail system wherein the failure of the ground of soil nails is actually shown here where the failure surface passing through the nails and ground flows around the soil nails so wherein you can see that this failure of the ground around the soil nails can be seen and in this soil nail head bearing failure where this portion of the nail got punched or failed this bearing failure on the soil nail head can also case one of the failures and the other one is that local failure between the soil nails that is the facing element failure basically here and this can actually cause because of the inadequate facing thickness and this is the local failure between the soil nails. The other one is that potential failure of the soil nails because of the rupture or breakage of the soil nails can take place with that what will happen is that the nail the slope surface moves this forward and then there is a possibility of the instability and the pull out failure of the ground grout interface that is ground and grout interface that is here which is can possible and grout or grout interface grout reinforcement interface. So these things will lead to again the slope to move outward and then undergo failure. Then we have bending or shear failure of soil nails suppose if the installed soil nails not having adequate bending and the resting against the shear then there is a possibility that along the potential failure surface there is a possibility of the bending and the shear can be observed which can lead to you know the failure. So with the locus of the maximum tensile force mobilization then matches with the failure surface at this location here. Similarly here for the potential internal failure modes of a soil nail system in a continuation and this is the structural failure of the and the connection failure at the soil nail head that means that nail and the soil head will can get detached and then the slope surface can actually you know can deform. So here this is the structural failure connection or failure of the facing where in you can see that the structural failure of the facing the facing is subjected to failure and here failure of the facing reinforcement connection which can actually is depicted here. So these are the typical internal failures of failure modes of a soil nail system. So in this particular slide a typical you know use of this technique for installing this usage of this technique for slope production in an underground excavation is shown here. What you see here is a short created surface and then the nails are actually placed here particularly with the presence of this buildings which are close to the slope surface and this seems to be very very viable and then is required because the protection of the slope is very important and to safeguard the existing structures also to facilitate the construction in the area of the interest. So here this is a typical example which is actually shown how the rays of the groundwater table and infiltration of the rain water creates seepage pressures within the slope and with this what will happen is that when the buildings are actually constructed close to the hill slopes and this type of slopes are prone for you know can cause instability failures and with the surrounding soil is the slope is actually made of slope then the adoption of a soil nailing technique for this is a viable option where in you know this technique ensures that the slope is actually is you know protected and then you know the safety can be ensured. So this is a typical application for this but however the effect of the raising groundwater table and the soil nail ground interaction need to be addressed so that the you know this can be attended properly. So the other application of this technique is to you know using for railway suppose if existing tracks and new tracks are to be laid then when it is in cutting need to be widened or steepened so in the process what actually happens is that for placing the new tracks and then the slopes can be protected by using this technique so here the different facings are used sometimes we are wire mesh fencing or you know gavion wall facing or there is you know these are the plates which are actually head and these are the nails so you can see that the nails are actually placed at a certain horizontal and vertical spacing covering the entire area so this ensures that the stability of a this particular slope and you know helps to you know creating additional space for laying new tracks and all. So this is a typical cross section of a drilled soil nail slope is shown here and where this is the facing and some geocomposite drains are used to facilitate the drainage of water rainwater and this is the close view of the nail head along with the nail bolting arrangement so this is the nail head nail bolting arrangement you know detail view is actually shown here. So this is you know how the construction of soil nailing is shown a typically preparation of the slope surface and mobile drilling equipment arrangement and driving of the nail and then installation of the steel bar and then grouting process this is shown basically to acquaint with the how the construction happens in the field. So now looking into you know the how you know the type of you know what should be the inclination and what should be the you know the length of the nail and what should be the facing how you know these actually affect on the you know slope stability parameters can be looking into it. So as we have discussed with that soil nailing technique particularly the passive inclusion technique and these are closely spaced along the horizontal surface and two patterns are possible one is square another one is staggered arrangement wherein two patterns are possible one is square arrangement where SH is the horizontal spacing SV is the vertical spacing and this is called as a staggered arrangement in which the nails are actually spreaded over the surface and with the mobilization of a slope movements in the active zone the forces tension shear and bending are actually mobilized in this nails and the resistance is actually developed to the way it is actually shown here. So when there is an increase in ground water table within the slope either due to rainfall water infiltration so there is a possibility that the forces in the nails get enhanced. So here in this particular slide the factor of safety of the nail inclination for different slope inclination shown here. So here two very steep slopes are considered one is 63.43 degrees which is nothing but two vertical one horizontal the other one is 79 degrees slope inclination which is 5 vertical one horizontal. So as can be seen that with a back slope of inclination of 0 that is the slope surface is horizontal you can see that as the nail inclination increases there is increase in factor of safety and then there is further decrease in the factor of safety. So this implies that there is a certain optimum inclination for which actually the factor of safety is high. So this analysis actually performed by incorporating nails and by using modified Bishop's method of slopes, the Bishop's method of slices and with this the factor of safety of a soil nail slope concept based on limit equilibrium approach could be obtained. So it can be seen that for a nail inclined at 10 degrees for a slope of inclination of 79 degrees it is found to be optimum and for a nail inclined at 25 degrees for a slope inclination of 60 degrees were found to be optimum you can see that further increase in the nail inclination lead to the decrease in factor of safety. So it must we must remember that the nail inclination need to be selected based on the slope configuration whether it is with the back slope inclination or with a slope inclination and in this particular slide two different thicknesses like four different thicknesses are actually considered with an increase in thickness of the facing the factor of safety was found to increase. So you can see that with an increase in thickness of the thickness of the facing then the nail the contribution of facing enhancing the stability of a slope can be seen. And if you with the variation of horizontal spacings let us say that for horizontal spacing of 1.3 meter 1.5 meter and when the vertical spacing is increased for example here with a vertical spacing of 1.5 meter so what you can see is that with an increase in vertical spacing there is a decrease in the factor of safety. So it can be seen that say for example with vertical spacing of say horizontal spacing of 2.1 meters and vertical spacing of 2.1 meters the factor with an increase in vertical spacing there is a decrease in the factor of safety which actually can be seen from this analysis. Similarly here the diameter of the nails basically we said that the reinforcing bars are used and these reinforcing bars are actually having different inclinations different inclinations as well as the different diameters. So particularly these reinforcing bars from 28, 38, 42 mm these are the normally available materials the torque state bars they are used and so as can be seen here with an increase in the diameter for example here this is for the nail diameter of 20 mm and 15 mm then increase in the factor of safety and this also found to the nail inclination also found to have the similar effect for a 60 degree slope inclination which is actually shown here. So in this particular slide the influence of pressure blouting on the slope stability is actually shown the reinforcing effects of pressure blouting on the slope stability. So here in this FEM analysis of a gravity grouted soil nails is actually shown here and this is the failure surface of the gravity grouted soil nail surface and this is again superimposed here and this is in this this is the pressure grouted soil nail surface. So this is after Kim et al 2013 where the developed slope failure surface for the gravity grouted and pressure grouted soil nails from the maximum plastic strain deformation plots. So these are actually failure surface were actually developed for the gravity grouted and pressure grouted soil nails from the maximum plastic strain distribution plots and the slope reinforced with pressure grouted soil nails exhibits expanded failure surface the failure surface was found to move towards the passive zone or a stable zone and compared to that of the gravity grouted reinforced slope and the grouting pressure may increase the stiffness of the reinforced slope system. So what is happening is that the grouting pressure influences in a big way in enhancing the stability of the slope because the surrounding soil is relatively compressed or compacted and offers higher resistance across each nail and that makes the pressure grouted soil nails for found to perform grouted soil nail stabilization technique were found to superior than the gravity grouted soil nail stabilization technique. So with this what we have understood is that the reinforcing effect of the pressure grouted soil nails are superior in enhancing the slope stability of a typical slope which is actually shown after Kim et al 2013. So this is you know adoption of the soil nailing technique for a water treatment plant in one of the sites in Kerala and wherein this is a slope of about 24 meters height and wherein at the top of the slope a 100 kilo Pascal's you know unit which actually imposes a load of 100 kilo Pascal's water tank was actually placed for supplying water by gravity method to the surrounding villages. So the soil is basically a laterate type of soil and which actually gets softened during you know the rains particularly the ingress of rain water. So it can be seen that the patches of water seepage can be seen here. So here in this you know a spacing of 1.5 meter by 1.5 meter is adopted for a typical you know nail lens and nail inclination is adopted and by this analysis was actually carried out by Taldren you know software which actually includes the effect of the soil nails in the modified method of bishops method of slices wherein the this is considered and the this particular site was actually you know done basically to increase the stability of a slope to carry the additional load of 100 kilo Pascal's at the top of the slope and to house the water tank at the top of the slope. So then another you know stabilization technique what we have discussed is called biotechnical slope stabilization technique and which is gaining popularity and wherein here a selected you know seats were placed along the slope and these the roots of these plants are penetrated into the ground and then the roots surrounding soil interaction were found to enhance the stability of a slope. So very recently also some of the live poles are actually used for enhancing the stability of a slope and wherein these are actually used for improving the stability one of the natural way of these using the technique of vegetation the vegetating the slope surface and enhancing the stability. So in this particular slide a typical you know live cuttings and a compacted fill is shown and mostly this is actually adopted for as well as for natural slopes or manmade slopes so this actually ensures the green effects surrounding the areas. Then in this you know this typical combination of you know in nowadays is combined with erosion control blankets these erosion control blankets are embedded with a materials like jute which is jute or a choir which are actually placed on the slope surface in a blanket form and they are actually also you know attached to the slope surface in the form of a pegging and then live facins were placed and planted which actually helps you know the combination of combined application actually wherein both you know erosion control blanket and live facins helps in maintaining the slope stable. So here these are actually adopted as also in the combination of even soil nailing or by using you know geocell on the slope surface where the erosion also can be controlled and as well as the live facins can be used for enhancing the stability of a slope. So in this particular slide what actually has been shown is you know a particular slope how it actually has been you know created by creating a steps and a small berms here along the berms these you know selected plants are actually placed and then after you know this is a typical vertebrate grass system after certain time it can be seen that you know these growth of this grass actually turns this entire area green and this is you know one of the promising area for the you know slope stabilization where the lot of work is actually also happening. So in this slope stabilization techniques you know particularly after having discussed the several causative factors of the slope failures what we have understood is that a different types of you know methods are there for enhancing stability of slopes like you know simple techniques of you remove of the you know materials from the head of the slope that is the you know replacement with you know heavier material with lighter materials or by benching the slope at the top portion that also can actually enhance the stability of a slope or we also said that the use of light materials like geofoam helps in enhancing the stability of a slope then we also discussed that you know there are methods like drainage techniques in this there is surface drainage techniques and subsurface drainage techniques and this is a prime and important technique where if the slope is actually some has efficient drainage system the stability of a slope can be enhanced. Nowadays you know the techniques of combining reinforcing the slope as well as you know facilitating the drainage these are actually called as hybrid way of stabilizing the slopes are in vogue and are being researched widely and then we also discussed about a typical technique of stabilizing the slope by using stone columns or gravel drains so they these stone columns or gravel drains work for you know as a dual function one is that to drain the you know also the these stone columns can also function as a gravel drains to drain the water and also they can increase the resistance against the slip and increase the amount of resistance in addition to the soil shear so they can actually have you know further effect in enhancing the stability of a slope as well in reinforcing the slope as well as as a facilitating as a drain is actually something called you know deep trench drains and another technique what we have discussed is that you know a type of technique by using chemical hardening where in the technique of you know using the lime and lime slurry injection or lime columns is one technique we have seen and in addition to that there are also some technique like use of ultra osmosis that means that by placing you know the electrically charges from positive charge and negative charge and this actually also helps in you know in improving the stability of a slope that means that the slope the water is actually drained by maintaining a electric potential between anode and cathode and that makes the you know the slope surface hardened and increases the shear strength of the soil and then we also discussed today in one of the techniques which is soil nailing technique where in this is an institute reinforcement technique which can be adopted for existing slopes natural are also man made slopes like highway railway embankments which are required to be protected or stability to be enhanced and this also technique can be adopted for you know existing slopes or slopes to be exposed for excavations as a shore protection system as a where in this is a type of shoring for the you know shoring technique for enhancing the stability of a you know a particular slope and this can be done both for the insular in the nails for this technique is done from top to bottom construction so nails are actually installed from top to bottom up to the top of the slope and the finally we have actually discussed regarding the biotechnical slope stabilization technique where in this technique allows to maintain the you know a selected facins or grass systems can provide stability of a slope in a better manner.