Loading
Notes
Study Reminders
Support
Text Version

Natural and Man-made Environments

Set your study reminders

We will email you at these times to remind you to study.
  • Monday

    -

    7am

    +

    Tuesday

    -

    7am

    +

    Wednesday

    -

    7am

    +

    Thursday

    -

    7am

    +

    Friday

    -

    7am

    +

    Saturday

    -

    7am

    +

    Sunday

    -

    7am

    +

Video 1: Natural Environments
We have been talking about general introduction of environmental geomechanics and I have givenyou a lot of logics until now about the scope, the philosophy, what are the issues whichenvironmental geomechanics specialists or environmental geotechnologists are facingin contemporary world and in particular, how to deal with these situations.So if I sum it up, whatever I have discussed until now, the environmental geomechanicsis a branch of engineering and technology, where mainly we study the quality of waterand land resources. These are the basics or basic requirements for the sustenance of thelife. We always try to find out an optimal solution between the different constraints,which I have discussed in the previous lectures.And another activity in which environmental geotechnologies are involved is the transport,use and disposal of hazardous waste and then treatment of the waste water and water, earlierit used to be a domain of environmental scientists, but now I hope you will realize that withthe recent developments and technologies, which are being implemented, the role of environmentalgeotechnologists becomes very, very important and of course the reuse of water.We also talk about the investigations or the analysis design of foundation systems, seepagecontrol, earth and dams, water resource structures and we are quite interested in studying, whatis the response of the foundations and embankments to environmental activities and these environmentalactivities can be grouped in two categories. The first one is man-made and another oneis the natural process or natural calamities, we call it.So here I have given you some examples of what are the manmade activities, though wediscussed quite in details. Primarily the manmade activities would be industrializationand population explosion and once you talk about these issues everything is a part andparcel of this including the scarcity the land, which I talked about in the previouslecture. The second issue is the natural environmental activities.And I hope all of you are now seeing that all of us are facing in a big way the disasters,which are occurring naturally or which could be manmade also. So this is what the pointof discussion in what causes what. Ultimately the humanity and the society is sufferingand we have to try to come out of this situation. So when we talk about the natural activities,which are responsible to motivate us, alright, to become an environmental geotechnologiesand take up these type of assignments would be primarily earthquakes.Anything, which comes to your mind apart from earthquakes, see hurricanes. Tsunamis areplaying a very, very important role. I have been dealing with several examples in ourown country where post tsunami, the rehabilitation part particularly in Andaman and Nicobar areabecame a very big challenge. Just to give you a very quick example tsunami brings lotof sediments along with it and these sediments get deposited on the coastline.And now the infrastructure on these type of loose unconsolidated sediments is going tobe a very big question mark. So something of this sort is being done in the coastalareas of the country. Hence, tsunami has become a very, very important thing to be studied,though I will not be discussing much about tsunamis in this course, because I am notan expert in the subject. The another thing could be cloudburst, alright. It is a naturaldisaster.So I hope you understand what is meant by cloudburst. All of a sudden a tremendous amountof rainfall taking place in a limited time, alright. Mostly this happens in the (()) (04:27),upper reaches of the Himalayas or the hills, but nowadays it is becoming very common incities also, alright. This could be the change in the climatic pattern. So in what way thecloudburst could be linked with the practice of environmental goemechanics as the heightof imagination.I hope you can make it out very easily. When cloudburst occurs, the chances of landslidesbecome extremely, you know, severe and landslides is a subject which every geotechnical engineerwould like to handle. So this is how things become interdisciplinary and they get linkedwith each other. So hurricanes, tsunamis, design of foundations for extremely high windvelocities.So until now you have been very conveniently designing the foundations for insignificantloads. I would say insignificant moments, but recently you must have seen when the easternpart of the country was hit by cyclone, what was the name of the cyclone, Fani alright,very similar. So whatever disaster occurred and how to mitigate this, that means you haveto revise the concepts of conventional geomechanics, where the moments for conventional buildingsare not taken into account much.So this is how the subject is getting evolved, you know. The moments are becoming more andmore important on the foundation system rather than the dead loads. Volcanic eruptions, sowe are lucky that you know we are in a country, where not many volcanic eruptions have beenseen yet, except for the islands of this country, particularly Andaman and all, but think ofthe countries or the civilizations, which are on active volcanic regions.So this is going to become a very big problem. One good example, which you can Google wouldbe, how this Japanese train, the lava, so that it does not influence the rehabilitation.So they channelized the entire lava and they are experts in this. So they are very goodYouTube videos which are available on this. So the volcanic eruption could cause significantproblems as far as the human settlements are concerned. What else could happen becauseof the volcanic eruption?Yes, I was talking about the molten state of the lava, which is flowing like fluid.So few years back you must have heard about volcanic eruption, which happened in Europeand because of that the East got disconnected completely with West, why? No idea, checkit out what happened. So when you have eruptions of particulate matter in the environment,the visibility and the density of air changes, you cannot fly through.So for several months the flights remain unoperational. Ultimately what happens it influences theeconomy of the nations. So suppose if you are totally disconnected from rest of thepart of the world, you are going to be severely affected. So these are the future domainsof environmental geomechanics. I am very sure which you guys must be you know facing I wouldsay. So the right time to gear up and adopt them as the future profession for geotechnicalengineers.Do not get limited to what you have been doing very conveniently because that part peoplehave already mastered. So I hope you have understood there is a series of natural disastersalright and these are mostly manmade. They could be natural also. Avalanche, I thinkwe have talked about. You know, movement of the snow on the hills. So this also a goodexample of how natural activities might create chaos, particularly in the upper region ofHimalayas.If you Google it, you will find lot of information on how avalanche influences these structures.Instability of the structure is caused by movement of the Avalanche okay. So unfortunatelywe do not offer a course of a cold region geomechanics in India, because we have ignoredcertain parts of the country. We never thought that they are the part of the mainstream.It looks like, but I am sure one of you or some of you should really take up these challengesand try to consider the geomechanics of frozen soils.So fortunately in our group, R&D group some of them are working in this area and we aretrying to see what is the response of the soils when they are subjected to varied environmentalconditions, alright. Anything which comes to your mind apart from this, floods, cloudburst.Floods, yes flooding also is a part of the mostly manmade nowadays, rather than you mustbe reading in newspapers every day what is going on and who is responsible.There is a big debate, which is going on. So be a part of the central theme of discussionof the country. You cannot be isolated. Yes. “Professor - student conversation starts”Enormous snowfall can be there. Yeah, it will result in avalanche. So the way you talkedabout NC OC materials normally consolidated, over consolidated soils avalanche is nothingbut over consolidated snow.So imagine the layers of snow getting deposited and the next you know deposition coming overhitting the particles and the system becoming more and more condensed is what avalancheis, alright. Fine. “Professor - student conversation ends” So snow mechanics andmechanics of the frozen regions is becoming a part of today's discussion. I will talkabout this in details.

Video 2: Recent Trends
What are the recent trends, which we might or might not cover in the realm of environmentalgeomechanics, but my idea is to keep you updated on what is happening internationally and thisis what the present day scenario is in geotechnical engineering, which I do not know whether youare aware or not. So the list is very long, but what I have done is, I have tried to stuffeverything in few sentences and just to give you an idea about what is happening in contemporaryworld and what geotechnical engineers are doing.Sky is the limit. So we start with the material science. You know. The present day geotechnicalengineering is mostly about the materials and these materials could be neo materials.Neo are the ones which are new, which are not conventionally existing, manmade alright.So flyash, silica fume, slags, different type of industrial wastes, which you are dumpingare all becoming neo materials, because I think we discussed in the previous lecturethat these materials require a very different and special attention of geotechnical engineers.We are also talking about the nanomaterials, different type of resins, zeolites alright,different type of synthesized materials and this is where if you remember, when I wastalking about the introduction of the course, I was saying that we talked about the interactionof geomaterials with environment with a view that we would like to understand, how thegeomaterial is altering and this alteration could be physical, chemical, mineralogical,biological and so on.So this has become out of the day, where people try to understand what type of alterationsthe material undergo, when the interaction starts and I think I have described interactionenough in the previous lecture, how the geomaterial contaminant or environment interaction occurs.So the perception is going to the basics of the materials, where we want to understandrocks, soils, groundwater, manmade materials as the basic materials.And then we want to understand the mechanics of these materials alright. So with this inview, the characterization becomes very, very important. I will be talking a lot about thecharacterization of geomaterials in the subsequent lectures. Mining and mineral engineering hasbecome a part of geotechnical engineering. So a lot of mining activities are being planned,executed by the geotechnical engineers.And there are some people who are working in the areas like geo-environmental issuesrelated to mining. A lot of scope of understanding the materials, how do they react and how Ican use different types of materials to support the mining activities. I hope you can realize,slope stability anybody can do. So when they come to a specialized surgeon, then the problemhas to be different, alright. This is the quick answer.So it is not only the slope stability, but there are a lot of other issues. Geohazardmitigation, I cited several examples of geohazard, anything which is related to geo, earth isa hazard these days. I mean we have discussed so many cases. There is a big boom in theinformation technology and artificial intelligence and expert systems in the realm of geotechnicalengineering. How many of you are aware of this?There are a lot of expert systems. Abacus is a simple mathematical formulation, nothingelse. Check it out on net SoilVision is the name of the company and their products areexpert systems products, geo, SoilVision, alright and this was established by ProfessorD. G. Fredlund and his son, Murray Fredlund in Canada, SoilVision. So this is a system,which contains several modules and the question which you are asking about the mining.If you get time, students originals are available online and you can have trials, you can havetutorials, you can read a lot about it and this is going to be a game changer for youguys. The commercial versions are quite expensive, but as far as your stage is concerned at thistime moment, you can start with the tutorials, which are available on the SoilVision andyou can read about what is happening. Just to add quickly, what these IT and AI does?Gone are the days, when I would like to do hundreds and thousands of the samples, thetests in the laboratory. We do not have time. Look at the infrastructure you know the wayit is growing. So how many labs in the country or in the world can really facilitate thistype of testing, not many. So what is happening in today's world is, people are working onspeculative modeling and that is what SoilVision does.So if I know few properties of the soils, let us say texture, particle size and somefundamental basic property like specific gravity, I can speculate all other properties, shearstrength, heat migration, contaminant transport, everything. So this is what is known as speculativemodeling in geotechnical engineering, where a lot of IT and AI is being involved. Thereare people who are working in neural networks ANN.I am sure you must have heard about, artificial neural network. So there is a lot of peoplewho are trying to train the soil properties by using ANN networks, the way your mind works,neurons in the mind. Similarly they are training mathematical models, by which if you givesome information you can retrieve the information. So some of you must have studied about SQL,that is sequential query language, is it not?So sequential query language is the one which is quite useful for geotechnical engineersand this is where our profession interfaces with Computer Science guys. So the guys whoare testing soils, they have a big data set of say about 7,000 or 8,000 soils and if Iask a question, my soil with these 3 attributes, how it would exhibit the engineering propertiesalright roughly. So this is what the speculative modeling is, query based language and in asequence you can ask the question to retrieve the answer.Is this fine, SQL. So those of you who are interested should read about SQL and thiswas going to be a good profession. So expert systems are becoming very useful. Structuralpeople they used to use expert systems quite a lot for designing their bridges alright.So but now geotechnical engineers are not much behind they are also using quite a lot.This is something very recent bio-geo interface, which deals with the molecular mechanics.I do not know, how many of you would be having the taste of all these things, but many timesthis is forced and many times it becomes a part of your personality to pick up somethingnew and work on it. So in our group we are doing a lot of bio-geo interface. We havedone fundamental studies of how soils react to microbial attack and the whole PhD is doneto quantify this process to understand, what type of alterations system undergo, when thebacterial activity or the microbial activities attack the geomaterials alright.This process happens in nature and it is so sad that very conveniently geotechnical engineeringpeople have forgotten about this. So normally what we do is, we bring the samples from thefield, we put them in the oven and we create a different type of soil, which never existsin the field and this is one of the reasons which we were discussing that why the systemsare failing, because we are not doing the real life modeling of the material.We are not talking about the real property of the material. These are the altered stateof the material. So most of the tests which you do in conventional geomechanics you havevery conveniently saturated the material, clear to get rid of the third phase, whichis air and that is the one which gives the most notorious characteristics to the systemwhich has to be dealt with. So bio-geo interface is the one, which is quite recent.If you get time, you can go through it and you will find that this is something whichis going to be a game changer, then all your conventional theories are going to get changed.Once you talk about the presence of microbes in the geo material and this is where molecularmechanics becomes very, very important to be studied by geotechnologist. Fire protectionengineering, where do you think that this can be applied in geotechnical engineering?Any idea?Do you remember what is 26/11? There is one good example of you know how fire protectionengineering can be included in geotechnical engineering. There are ample examples. Anotherexample would be, let us say, you are designing the foundation for foundries. You know whatare foundries? Metal processing units, you are designing hammers or you say you knowwhat do we call them as punching units, where something falls on a system.Another good example would be, let us say missile launching pads, rocket launching pads,a lot of temperature gets generated and if the soils are not worthy of sustaining thishigh temperature, your simple shear strength theories are not going to help you in designingthe foundations. So these are the issues. Another interesting thing would be those ofyou who are very, very eager to know what are the other scopes of fires in geotechnicalengineering.Forest fire, which is a recent topic, is it not? Every country is facing this problem.So what happens when the fire spreads in the, let us say, forest, what is going to happen?The vegetation gets burned and because of that the properties or soils also get changed.So again you have created something, which is not naturally existing. Now this fire couldbe manmade or this could be natural, clear, but the whole idea is, what is the end effectof this.The end effect of the forest fire is, it changes the fundamental properties of the depositsand then the rains come, the chances are the erosions are going to be maximum from thesetype of deposits, clear. So, loss of vegetation, loss of organic matter from the soil, becauseof the fire is becoming a very important topic to study these days.So infrastructure engineering, creation of land, I think I discussed this in the class.So when you do reclamation, dredging and reclamation is something which is now catching attentionof people rheology of soils and why rheology of the soils, because when you do dredgingand land reclamation, you dig out the soil from the sea or the of the water bodies andthen you spray it to recast it alright, to resettle them.There are several examples in today's contemporary geopolitical situation. What is geopoliticalsituation? Understand what is happening in the South China sea, what India is doing inthe southern part of the nation in the islands alright. So most of the countries are veryactive and this has become an interesting subject, where land creation has become avery big issue. Very recently, I do not know whether you are aware or not, India openedup a new container terminal which is almost in the middle of the sea.That is in Bombay, Fourth Container Terminal. So check it out on net. You just see the Googlemap and check it every year if you see that Google pictures, you can realize what is thenew addition and that is the best way to learn, how much active the geological boundariesthese days are. I will talk about these issues and the prevention, sorry preservation andrestoration of monuments and old structures and the habitation also.So wherever the minerals are involved, wherever the structures made up of soil, in the soil,with the soil are involved, remember geotechnical engineers have to be there. So most of theissues which archaeological society of any country faces would be restoration and preservationof the monuments, is it not? How would you preserve the foundations of old buildings,how do you let them remain, the way they are. They should not deteriorate over a periodof time.We do not want to lose the history and heritage of the country. Is this correct? So the bigbench of you know professionals, who are into these type of subjects and fortunately I alsogot enough opportunities to work for some of the ancient caves in the country, whereit was a R&D cum research project for us. This is something very interesting. I wastalking about the arctic and the cold region geomechanics and people have already startedworking on lunar and Martian geomechanics.Are you aware of this? Check it on net. There are so many papers. In fact, in our lab alsowe have published a paper on, I do not know, whether you have seen this or not. There isa big crater in Buldhana district of Maharashtra and this is where the meteorite fell longback, millions of years back and then we were trying to study, how the soils got createdwhat are the peculiar properties. So the time has come when people are talking about extraterrestrialgeomechanics.This is another interesting branch of geotechnical engineering, where a lot of work is beingdone, forensic engineering, where you know the legal issues associated with the problems,I have been talking about, are being dealt with failures, post failures, dams are failing.Floods are everywhere, the type of property damage and roads are getting washed out. Sowho is going to pay for this? These projects are insured.Insurance companies, they do not want to shell out the money so easily. So what do they do?They appoint people like us. So evaluate the entire project and give us a correct picture.They call it as a root cause analysis. What is the root cause of the problem clear? Wasthe structure not designed for the floods, excessive rains, landslides and so on. Sothis is also a very interesting area, in which I think some of you should take a lead.Not many guys are present in the country, at least I would say, who are experts in theforensic engineering and what basically deals with is the engineering aspects of legal problemsassociated with a project mostly. I hope you are aware of DPRs, detailed project reports.So if you check it on net, what is the problem with DPR and you will get a lot of answers.You guys are blessed. Everything is available on the net. So you just check out what isDPR?What are the implications, how the projects are suffering? You will get a lot of informationalright and last but not the least is energy. Some of you are quite fascinated with gashydrates. So I am going to discuss a lot about energy geotechnics. What energy, why energyis becoming a recent trend in geotechnical engineering? What it has to do with the geotechnicalengineer practices? So how does this list look like?How many of you are aware of how much about these subjects. Yes. “Professor - studentconversation starts” Forensic engineering, Forensic Good, why? If we know how the problemsare caused, we can like in the future, we can see that if you do like this, this isgoing to happen, so. Very nice, I am so happy and then you should become an expert. So youshould read the laws of the land first and then try to assimilate this with the practiceof geotechnical engineering and try to find out the loopholes.Suppose, if I construct a structure today and tomorrow it settles, who should be blamed.There are so many cases, I am sure you must be coming across Times of India, nationalnetwork reports, lot of issues like this. Roads have been done and tomorrow road cavesin, who is responsible? Good, Mitra. Maybe artificially intelligent and expert. Why?The data that I get, we can actually speculate the models.Yeah, a lot of work is being done in this area as I said, predictive modeling. I willbe using these concepts quite a lot in practice of modern day geotechnical engineering.