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Subject Organization of Environmental Geomechanics

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Video 1: Civil Engineering
Let me introduce the topic and I will start with the civil engineering.Most of you are civil engineers and all of you are civil engineers.So if you go to the copybook style of the definition of civil engineering it tells youthat our activity is to design and construct public works and this has been coming on sincelong since several years and sometimes, we also say that we are the designers and buildersof the quality of life.But over the years this definition has got changed and there is a shift and this shiftis a transformation.So why there is a transformation because the society is evolving and when the society evolvesthe old concepts keep on changing over the period of time and so has happened with civilengineering as well it is not the same civil engineering what we used to study when wewere students and what we are professing now as a professor.So you will observe that there is a marked difference between what you used to be andwhat it is going to be and what it is right now.So if you read this statement carefully the profession revolves around the practice ofimproving and maintaining the built and natural environment all right.To enhance the quality of life for present and the generations to follow.So what comes to your mind why there is a shift like this what has forced this shiftto occur.So I am sure if you read this definition again and again you will get this feeling that thingshave changed and why things have changed is what is written over here.So civil engineering is mostly the practice of improving and maintaining the built andnatural environment alright.So the definition of civil engineering itself includes environment into it and when we talkabout the built environment and the natural environment.What we are converting to is the naturally given environment like you know where ourpredecessors are living in caves in jungles and in forest areas and from there the transformationhas occurred to the built environment which is mandate.Is this fine the emphasis is on improving and maintaining both the environments it isnot only the creation now when you talk about the improvement and maintenance what are theobvious things which come to your mind you know what type of materials, I am going touse number one.What type of practices I am going to use what type of optimization techniques I am goingto use to optimize the materials which I am going to use and the type of techniques Iam going to use, and this is where we also talk about the sustainability.So sustainability term has got inbuilt over here if you read the last line, so this isa quality of life but keeping in view the sustainability issues and this is what ismeant by present and future generations.That means you are talking about the improvement and maintenance of the structure which weare developing which you are creating in a sustainable manner all right.So the most recent term which has got added to a profession is sustainability.So this is what actually I am going to elaborate more in this discussion under the realm ofenvironmental geomechanics.So if you read again the definition of civil engineers who are the designers and buildersof the quality of life the sustainability term was missing in the earlier definitionand that is what actually we are trying to cater to.So this is the main emphasis from civil engineering to civil engineers what shift has occurredin the recent past and that is what actually environmental geomechanics would try to touchupon.How this transformation has occurred if you remember in lecture number 1 and 2, I hadtalked about the need or the requirement for changing the concepts of the classical subjectand redefining them for our alright.So whatever exists cannot be applied several times.So how we are going to change those concepts to solve the problems of the present day societyin a most sustainable manner is the basic theme of environmental geomechanics is thispart clear.

Video 2: Subject Organization
So if you look at the subject organization and what is the genesis of environmental geomechanics this is an interesting philosophy.Basically all of us are geotechnical engineers civil engineers converted to geotechnicalengineers and now we are in the process of getting converted to environmental geotechnologist.So if you look at the subject organization geotechnical engineering which basically dealswith geomechanics all right and when we say geomechanics we talk about normally rock mechanicsand soil mechanics and these are the tools like sea rock and soil, or the materials andthe mechanics is the principles of physics to apply a problem by using mathematical tools.So when you are dealing with the materials like rocks and soils and you are applyingthe concepts of mechanics to solve the day-to-day problem like foundations retaining structureseepage, stability, slopes, dams these are the applications or the concepts this is whatis classical.Now so what has happened in the past we have been talking about only the materials, rocksand soils without realizing the effect of environment on the material.There are several activities right now which people have identified both naturally occurringor man-made where rocks and soils might get affected when they come under you know threatof extreme climatic conditions.So, I do not know whether you are aware or not say any country’s nuclear program everybodyevery country wants to become an atomic major is it not that is what you are reading newspapers.So there is the role of geotechnical engineers in what way they can help the nation to becomea nuclear power.So most of the time the ore comes because of the mining clear we call them as the miningissues sorry environmental effects on mining processes or sometimes we also call it asthe influence of mining activities on the environment.So when you start from the process of the fuel cycle let us say particularly for eitherthermal power or for the nuclear power.So the first step there is you do mining you take out the ore it could be coal also whichis used in the furnaces.It could be the ore which is containing you know nuclear activity also clear so good examplewould be uranium let us say.So from the mining I get these ores I process them some portion of this is unused whichis known as tailings we discard them somewhere.Whatever is the process part we bring it to the industry we use it for our purpose andthen again, we produce a lot of waste out of it clear.Now this is the catch, and this is the beginning or the genesis of the subject environmentalgeomechanics.Now how you are going to link it with the rock mechanics and soil mechanics.Rock mechanics gives me the concepts of the material like rocks which are very imperviousbut might be fractured also but they are solid bodies in which I can dispose highly toxicwaste material and because of its low permeability the geoenvironment is not going to get affectedyou agree.So this is one situation where whatever industrial toxic waste is coming out of the industrialunits can be disposed in the rocks by virtue of their extremely low porosities and extremelylow permeabilities.But in the process what is going to happen when you are dumping the waste over therewhich might be having chemical attributes like concentration of chemicals associatedwith this or very high temperatures clear.These are the two attributes which we are interested in right now they are going toaffect the rock mass in which the waste has been disposed this is one of the examplesof what I was citing about the man-made activities which are influencing the geomaterials allright directly or indirectly.There could be another situation where whatever industrial waste is coming out, I might bedischarging it directly in the ground all right surficial discharge.So in that case what happens the top layer of the geo materials are soils they mightbe getting you know interacted with the industrial pollutants or the ways which you are discharging.So this is where the material like soil comes into the picture.In other words what is happening is by human activities or natural activities the geoenvironmentis getting affected contaminated influenced and that is what I have written over hereas far as the classical concept is concerned, we do not talk about any contaminant, presenceof contaminant in the system everything is very neat and clean.Most of your experiments you have done by using distilled water or tap water and thistype of situation is not going to occur in the field ever.The chances of studying hydraulic conductivity of a porous media which is located in thenatural deposits with fresh water supply is extremely less in present-day context why?Because too much of industrialization is occurring.So everywhere the pollutants are being discharged either deep inside the ground or on the surfaceand hence what is going to happen is the way we used to consider the mechanics of the rocksand the soils is bound to change.Because the effect of the contaminant or the human activities is going to be much moreon these systems and the I cited some examples.Now out of the two if I consider which material is going to get affected much and why?Rocks or soils so what is your guess why?So the question is out of soils and rocks which one is going to get influenced becauseof the environmental directory more and why “Professor - student conversation starts”hello yeah maybe soils are more affective things or compared to rocks because they aremore permeable or porous.Well I can always compare soils in such a way that they may become extremely imperviousmaybe because or maybe I am just countering your logic no its not possible all the timebecause the soil naturally occurring there is not so compressed.So well I can always compact place to get a permeability 10 power minus 11 and for rocks10 power minus 20 meter per second is practically same both are impervious all right.Dumping area may be soil is not so compressed way or not that okay this is one of the logicscorrect yes.Same soil will be affected apart from this way give it thought its all about reasoningit has more surface area than rocks so why?Yeah you are right your answer is correct soils are having more surface area then rockswhy?Because particle size smaller no what is the correct answer look at the matrix in whichthey are you know bound.All the minerals in rocks are bound in a very very compact matrix as compared to soils doyou agree.Yeah that is one of the reasons yes you want to say something.So my logic is soils are the offspring’s of the rocks and the chances that the offspring’swill get contaminated adulterated deviated are much more than their parents you likethis logic.They are kids so the chances are they may get more influence from the environment inwhich they are kept.So your logic is also correct but the way I am looking at the material is like a offspringof the rocks and then I am saying this a young material as compared to rocks is this okay?So the chances are the young material will get contaminated, adulterated are much moreas compared to the parent material and then the logic comes porosity is less the matrixin which the minerals are bound is extremely compact.So if you consider the permeability the granite is extremely low why you know that matrixis so hard, so compact ,so intense that the minerals are not free to interact with theenvironment is this part clear this sounds good “Professor - student conversation ends”.So I have used lot of adjectives I have used lot of definitions I will lot of words todefine why this material is inert.So this is the first time I am using a word inert for a geomaterial is this okay and justto create a relative comparison between the rocks and the soils I have said that the rocksare inert, but the soils are not.So if this logic is correct, I would say that soil is the material which gets influencedby the environmental activities much more and when this happens, we have to includewhatever changes the material is undergoing when it comes in contact with the environmentfine?And how to quantify this and this becomes a big challenge and that is what we say theinfluence of the environment on the practice of geomechanics is going to be extremely challenging.So what we are going to study in environmental geomechanics is first of all we will try tounderstand the fundamental properties of these soils and the rocks what properties make themvery conducive or vulnerable to the environmental impact and once we have understood yes, theenvironment is going to impact these properties more the next question would be how to quantifythis.So that once the quantification has been done, I can utilize this concept in my design practicesis this part clear.“Professor - student conversation starts” After quantifying we can go for what can bethe effects of yeah once quantification is done, I know how good you are as comparedto me otherwise this is all aspect it is qualitative, I cannot fit this data in a computer program.But the moment I have quantified a number the moment I said this property has changedto this by this number I can do mathematical modeling, I can do numerical modeling, I cando modeling later on.So the big challenge is first of all try to understand the material try to understandwhat is the influence of the environment in which it is kept, and this could be naturalas well as man-made and once we have understood this, we will try to quantify how much changesthe system exhibits because of this interaction.Good example of environmental influence would be suppose you are making embankments.Now embankments are exposed to the sunlight forever is it not?Do you perform any tests in the laboratory to show or to exhibit how much the materialis getting degraded because of the sunlight for 40 years,50 years ,100 years this is aquick example so when you make railway tracks embankments all right when you make dams,they are getting exposed to the UV light from the Sun.We never talked about how the material is deteriorating over a period of time is thispart okay because the conventional subject does not include these effects its a quickexample how the material is getting deteriorated, how the material is getting upgraded becauseof some other activities.So this is what actually we are trying to focus upon in the conventional design likeembankment design for the design left we treat the materials even soil is inert.Like I presume that my grain size remains same it would not alter very good so why failuresare occurring you are using the best possible software’s you are using the best possibledesign techniques.Even then the failures are occurring so what comes to your mind the patient is not gettingtreated even after giving the best possible treatment and diagnostics.So what is the problem.Treatment failure can be due to like design problem also know I said I am using the bestpossible design practices.Nowadays the best possible design software’s are available I can get the best possibledesign parameters also by doing very sophisticated instrumentation and testing.But even then, failures are taking place why?So are you realizing the shift now at every stage I am asking you a question why?So she said you know surface soils are interacting more with the environment my first questionwas why, and somebody said rocks are not really interacting with the environment again thequestion is why?So we are going to ask a lot of whys?how? when? where?so what?so the more and more you question what happens the more and more answers you get.So truly speaking environmental geomechanics is nothing but asking more and more questionsto yourself and challenging what exists in the practice.Have you come across as any case in which you have saw that every design and every parameterswere okay, but they have not taken environment effect, and something has failed so many buildingsare failing in Bombay city and cities Delhi and so where everywhere in the world why?Calcutta bridges are failing why?Bridges are collapsing dams are collapsing why?Imagine see these are the questions which people are asking these days.So whatever was done 50,60 years back yes it has lived its lives we live for 60 years,70 years, 80 years these structure there will lived for the same time clear “Professor- student conversation ends”.So the way you want to retrofit your body rejuvenate your body these structures alsohave to be rejuvenated is this fine.So we will see how to do all these things.So this is only the preface of the subject which I am talking to you about.