 in brace structures doing earlier discussed about this design parameters. Now next part of your design parameters types of load first one is your earth pressure if you see this earth pressure distribution diagram if I draw three earth pressure lines k p this is k p gamma h line and this is your earth pressure at rest gamma h line this is your active earth pressure at rest sorry active earth pressure gamma h line and this is my wall and this is your ground surface. So, generally what happen so this will be your p 1 in the strut p 2 then this is your p 3 now if I write if I draw the apparent earth pressure distribution diagram for particularly typical cases of braced exhibition generally the earth pressure distribution diagram it lies this is your pressure distribution diagram apparent pressure distribution earth pressure diagram it lies if you look at here it lies between k p to k p line to k 0 line then it changes from k 0 line to k a line k p line is your passive earth pressure line k 0 is your earth pressure at rest line and k a is your active earth pressure line. So, this earth pressure distribution particularly in braced court it is varying between k p to k a line and k p to k 0 line and k 0 to k a line. Now what is your apparent earth pressure distribution diagram based on these based on these apparent pressure distribution diagram pressure distribution now if I draw a apparent pressure distribution diagram of kind of a sand as well as clay. So, this is height h now if I draw it so this will be 0.6 h and this is your 0. sorry 0.6 h it looks very small one let us put it in this way. So, that it will be now this is your 0.6 h and this is 0.2 h this is 0.2 h and this is your pressure p coming on the strut coming on the strut this diagram is your apparent pressure distribution diagram for sand. Now for loose sand what is your apparent pressure distribution diagram the loose sand apparent pressure distribution diagram will be this is p this value is your 0.8 h and this is your 0.2 h now for clay for clay for clay it is coming 0.25 h and this is your 0.75 h and this is clay and this is also p this is for loose sand. If you look at this apparent pressure distribution diagram because there is no specific pressure distribution diagram for particularly based structure as this earth pressure distribution diagram is varying from k p that means passive line to earth pressure at rest then earth pressure at rest to active line. So, based on this variation of earth pressure there are there are apparent pressure distribution diagram for in general for sand this is variation of apparent pressure distribution diagram it is varying from 0.2 h at the top then 0.6 h then for loose sand 0.2 h and 0.8 h for clay it will be varying from 0.25 to 0.75 h it remains constant the variation will be up to 0.25 h. So, these apparent pressure distribution diagram has been derived from this earth pressure distribution diagram and it is why it is called apparent this has taken as approximate because this pressure distribution is not a constant it is varying from k p line to k 0 line and k 0 line to k a line. Now, based on the apparent earth pressure distribution diagram what are the empirical equations for sand for sand p a is equal to 0.65 gamma h k a for clay for clay p a is equal to k gamma h and k is equal to 1 minus m 4 cu by gamma h. So, m value is varying between 0.4 to 1.0 for example, for calcutta soil for example, for calcutta soil for calcutta soil depth of cutting 4 to 8 meter m value is varying m value is varying for 0.6 and depth of cutting 8 to 12 meter m value is varying 1.0. This is a typical example of calcutta soil from this apparent pressure distribution diagram your p a value of sand is 0.65 gamma h into k a k is your active earth pressure for clay p a is equal to k gamma h k is equal to 1 minus m 4 cu by gamma h cu is your undrained cohesion m is a factor m is a factor it is varying from 0.4 to 1.0. So, based on the different cities different soils this m value is varying for example, for calcutta soil of excavation 4 to 8 meter m value is 0.6 for 8 to 12 meter m value is equal to 1.0. So, for strut load this is about your earth pressure distribution diagram and from their apparent apparent pressure distribution diagram from apparent pressure distribution diagram what is the value of pressure coming in the strut that is for sand clay this all about then strut load if this is my pressure distribution diagram if I draw if I draw this is the pressure distribution diagram on the wall on the wall on the wall. So, so this is p 1 this is your p 2 this is your p 3 how do you decide your strut load means what strut load you are going to consider for your design. Suppose this is my apparent pressure distribution diagram based on the one of the one of the pressure distribution diagram for sand or loose sand or clay. So, if this is the pressure distribution diagram on the wall this is suppose say this is the wall now find it out maximum pressure where it is coming maximum pressure where it is coming or maximum pressure where it is coming or maximum load where it is coming. Suppose this is a pressure distribution diagram suppose in this case p 1 and p 2 and p 3 suppose maximum load is coming about p 2 that means this strut load suppose p 1 is your strut load p 2 is your strut load p 3 is your strut load that means maximum strut load is coming about p 2 this has to be considered for design that means from pressure distribution diagram maximum strut load has to be considered for your design. Now once this part of your earth pressure distribution diagram is over then from there if you find it out pressure from there you will find it out your load on the strut then from this load on the strut maximum load on the strut means the design has to be done maximum load on the strut. Now what are the effects on the breast cut or major concern before we solve one example. So, what are the major concern on the breast cut or major effect major effects of breast cut. So, part one is your ground settlement if you look at this this is a wall and there are struts. So, as I said there will be a bottom hip say this is your volume v 2 and there is also a lateral movement this is called total volume v because of your ground settlement so this volume changes your v 1 and this is your delta maximum now volume of ground v volume of ground how much is your volume of ground it is your v 1 plus v 2 and l is your zone of influence l is your zone of influence zone of influence how do you calculate lateral movement lateral movement will be lateral settlement lateral movement will be calculated from your rigidity of your structure. If how rigid is your wall look at here how rigid of your wall at here in this position also how rigid of your wall in this positions. So, what happen when there is a ground settlement occur this if this wall is not rigid this will be deflected if this will be deflected there is a change in volume there is a change in volume this is called v 1 because of v 1 because of lateral displacement lateral displacement of your wall it depends upon your rigidity and v 2 is your because of your hip once it displace there is a chance the soil will be go inside. So, there will be hip so total ground settlement if I say total v what is the volume that means v 1 plus v 2 and what is l so it will displace ground settlement will occur it will go somewhere else it will merge that means up to this distance there will be zone of influence this length l has to be calculated first because unless otherwise if you do not know zone of influence then how to calculate in within that zone whether there will be any ground settlement or not. So, these both the parameters v volume as well as how much your delta maximum it has been calculated based on your rigidity of your rigidity of your structure. So, there are empirical procedures empirical procedure given by peck how to calculate your particularly rigidity of this if I write this empirical procedures here about your ground settlement. So, this is your empirical relation empirical procedure given by peck 1969. So, in this case peck 1969 if you look at here this is distance this parameter this parameter this parameter is your distance from excavation divided by depth of excavation. Now, if I draw this is my wall this is the wall that means what is it this parameter this parameter is saying distance from excavation as I said earlier zone of influence distance from excavation this is your l and depth of excavation from this depth of excavation that means where the ground settlement occurs this is your distance from excavation to depth of excavation it has been expressed in dimensionless form. So, that it can be used for anywhere else it can be used. So, this value is varying from 1 2 3 then 4 then settlement then next dimensionless parameter is your settlement by height in terms of percentage. So, this will be 1.0 and this will be 2.0 what does it mean how much settlement occurs how much ground settlement divided by total height h divided by total depth of excavation h suppose this is your settlement occurs that means this settlement is a delta. So, this will be delta by h this will be delta by h and in terms of percentage 1 percent, 2 percent and 3 percent both x as well as y axis this has been given in dimensionless form these are all your empirical relations given by peck 1969 for different soils if I draw it. So, this is your zone of influence 1 means zone 1 then this is your zone 2 this is your zone 3 now what does it mean if I am drawing it zone 1 means 1 means sand and medium or hard clay then 2 is your soft clay of limited depth below excavation then zone 3 or the 3 is equal to significant depth significant depth below excavation below excavation these are the observation here observed based on your sheet pile and most of the calcutta soil if you look at here for example, most of the calcutta soil is soft clay followed by a steep clay and it falls under zone 2 most of the calcutta soil falls under the zone 2. That means zone of influence will be if it is in zone 2 for calcutta soil for calcutta soil zone of influence is equal to zone of influence or l l is equal to zone of influence is equal to 3 times width of cut if you look at here it is going towards your 3 times so that means distance from my excavation is your zone of influence is equal to 3 into your width of the cut that means depth of excavation so it will be 3 times now based on this chart based on the chart first what what you are supposed to do based on the chart first you identify what is your soil what is your soil profile in the excavation then make a call if it is sand or medium or hard clay for sand it is varying from 1 to 2 maximum value is varying from 2 that means zone of influence l you can find it out 2 times into width of your cut then for zone 2 it is varying up to 3 so that means maximum value is your 3 into width of cut for zone 3 it is varying more than 4 from there you can find it out your influence zone from there you can find it out your influence zone also you can find it out how much your settlement the settlement by h in percentage for zone 1 is your 1 percent zone 2 is your 1 percent to 2 percent and zone 3 is your from 2 percent onwards it is varying suppose it is a zone 2 that means settlement is equal to 1 percent of total h that means h is equal to total depth is equal to 5 that means 5 into 1 percent so that means 5 mm so 1 by 100 is equal to 5 mm 0.05 mm so that means with these empirical procedure there are 2 parameters you can find it out one is your zone of influence other is your within that zone of influence what is your maximum settlement or maximum ground movement you can expect now this is one of the design parameter before you start because this will influence your completely ground displacement and the ground movement zone of the ground movement and maximum settlement it will also affect your total pressure distribution diagram this has to be found out from the beginning and then next part is your what are the factors factors for your ground settlement factors for ground settlement or factors influence the ground settlement if I start with this first one obvious it is your soft soil characteristics or you can write it out soft soil then it depends on shape and depth of excavation shape and depth of excavation then type and stiffness of method of excavation that means method of excavation means by means of mechanical or by means of manual then time means these are the factors generally affect your ground settlement if you look at here as I discussed by means of peck given 1979 the chart what is your soft soil profile if soft soil profile is your sand means the ground settlement will be less what if it is varying from soft clay then it is coming zone 2 or zone 3 then ground settlement as well as zone of influence it will be more then what kind of shape and depth of excavation what is your shape what is your depth are you going for a longer depth or deep depth or shallow depth this basically influence your ground settlement for example shape and depth what kind of what is the width are you how much excavation you want what width you are doing is like this is one type of excavation or you can do one is your small width then you can find it out your excavation you can go for excavation now what is your H value what is your depth are you going for a means deep excavation or shallow excavation if deep or shallow are you going for what is your width B of this excavation this is very small or large it depends upon shape and depth of excavation then next one is your type and stiffness of strut means suppose I am applying here this is my wall for example this is the wall may be diaphragm wall or sheet pile walls now at regular interval you are providing strut these are all your you can say that struts now once you provide the struts means what is the types of struts are you providing by wooden strut or are you providing steel strut or are you are you providing any what is the rigid means what kind of strut you are providing based on this strut you are providing what is the stiffness means once there is a ground movement this strut what will happen this initially this strut will resist lateral movement of your wall that means if this wall is supposed to displace laterally displace in this way what will happen this strut will keep this wall in intact that means it won't allow the lateral displacement of your strut so if it is not going to allow it depends upon its stiffness what kind of strut you are providing means steel wooden aluminum or very rigid strut as the more the rigid the strut will be more the rigid there is a less chance of your lateral displacement of your wall more the means the again it depends upon your economy also once you are providing the rigid strut the cost will be high so depending upon that strut particularly stiffness and type this lateral movement also of the ground can be reduced so next fourth part is also another another factor which is important method of excavation how you are excavating how how you are excavating means method of excavation means are you doing mechanically or manually in india generally what happen this man power is very cheap people go for manually the movement you go for method of excavation by means of manually that means by manual labor by layer by layer you are going what will happen it takes time it takes time manually once you reach here by that time what are happen this wall has been already displaced laterally because it takes time and chances of ground movement is high but if you are doing mechanically you can finish within the time so that before placing what will happen once you are doing manually once you start excavation and start your placing your wall before providing your strut this wall already started lateral displacement that means it is because of manually but if you do it by mechanically mechanical method so what happen there is chances of ground movement will be very less then another was one is your time construction time means particularly how your construction time more you take construction time more chances of lateral excavation will be more or ground movement will be more so as soon as possible you should finish this construction process so that ground displacement or ground movement can be avoided from this so once again this summarizing this is because one of the major factor ground settlement is your major factor for design for doing this ground settlement you need to have two parameter as I discussed earlier one is your zone of influence other is your settlement or ground movement once you know the zone of influence and as well as ground movement so this is my zone of influence this is your zone of influence and this is your maximum displacement of ground displacement once you know you can decide whether there is any structure whether already there is any construction whether already whether there is already any existing building so what happen generally this underground construction has been done particularly in metro areas you have to take you have to take consideration of your what kind of building what kind of structure is already there in zone of influence once you know the zone of influence you would then based on your zone of influence and delta maximum your stiffness has to be decided it is either way suppose before design you find that delta maximum is equal to 10 mm and zone in zone of influences suppose this is equal to say say kind of 0.5 meter or 0.3 meter so within this zone of influence suppose say there are multi-story building already existed already existed so that means before doing this construction starts you should be be sure that the there should not be this kind of delta maximum there should not be zone of influence so to protect this ground movement further what will happen you provide your steep struts so that it would not allow further this there is a lateral displacement of your wall so it is either way because this ground settlement has one of the major parameter this has to be taken consideration before starting of your design so maybe I will stop here next class I will start a complete design how to solve a problem taking into consideration of ground settlement thank you.