 In this section we will start with this bulk head it is nothing but your sheet pile walls and last class I have finished this some of the sheet pile walls but cantilever sheet pile wall. In this section we will see detail classifications and what is the sheet pile wall case one sheet piling structure case one then case two anchor rod and this is your anchored sheet pile this is your sheet pile and case three will be this is another example of anchored pile sheet pile anchored sheet pile these are anchor rods so where the sheet piles has been used as I said it is used for both large and small water font structures then it may be used pierce then it may be used for slope stability now it is kind of if you look at the sheet pile walls this is basically two types of sheet pile walls one is your cantilever sheet pile another is your anchored sheet pile sheet pile has been basically classified into two components one is your cantilever sheet pile other is your anchored sheet pile and the classification where it has been used it is used both for large and small water font front structures that means harbor dock and harbor structures it has been used also it has been used for protection of pierce and slope stability these are the three examples it has been shown in the figure first one is only sheet pile one end of the sheet pile it consists of may be it is a water this side or may be empty other end is other end is it will retain the soil mass and this line is called dredge line dredge line and the sheet pile is large if sheet pile is large to prevent against the bending moment one end has been connected by means of anchor rod and this part this as it has been connected with anchor rod that is why it is called anchored sheet piles another example case three if you look at this both the ends both the ends it is full of water it is full of water so sheet pile wall has been put it so with this anchors so that it allow allow the ships to be birthed in between the sea so so that this is a usefulness of how the sheet pile wall has been used now go back to cantilever sheet pile cantilever sheet piles have been classified again into two parts one is your free cantilever sheet pile and b is your cantilever sheet pile if you look at your free cantilever sheet pile why it is called free cantilever sheet pile this is my sheet pile this is your dredge line in case of free cantilever sheet pile the sheet pile has been acted upon by a concentrated horizontal load concentrated horizontal load at its at its top and there is no backfill above the dredge line if you look at the dredge line there is no backfill and the free cantilever sheet pile means entirely derived this stability by means of soil below the dredge line now come back to cantilever sheet pile in case of cantilever sheet pile and this is your dredge line the difference between free cantilever sheet pile and cantilever sheet pile if you look at here both have been acted by horizontal or lateral load both have been acted by horizontal and lateral load in case of free cantilever pile there is nothing above the dredge line neither this side nor this side it cannot retain soil may be water this side so entire stability of the sheet pile has been governed by the soil below the dredge line soil below the dredge line so I push inside the soil entire stability against the lateral load will be taken by the soil below the dredge line that is why it is called free cantilever sheet pile that means above the dredge line it is free one horizontal load lateral load has been acted so that is why it is free if you come back to cantilever sheet pile in case of cantilever sheet pile this is a dredge line and this is your soil this is one side of the cantilever sheet pile it will retain soil mass it will retain the soil mass that is why it is called cantilever sheet pile so that means the entire stability will be consider the soil here as well as soil below the dredge line considering soil here and here the stability has to be carried out remember free cantilever means above the dredge line there is nothing so it will be acted it is a free that means the entire load will be taken by cantilever action cantilever action and above the dredge line it is fully free so only acted by concentrated horizontal load if you look at the cantilever sheet pile so one side of the cantilever sheet pile soil has to be one side of the cantilever sheet pile soil has to be retained soil has to be retained other side of the dredge line so soil also there the stability will be determined from the soils of the one of the retain and soil below the dredge line so this is your cantilever sheet pile the classified into cantilever as well as free cantilever as well as cantilever sheet pile now come back to uncut sheet pile part two in case of uncut sheet pile if you look at here uncut sheet pile this is your dredge line dredge line means this line below this there is a full of soil soil above this it may be water it may be water so will penetrate the sheet pile such a way that it should go inside the soil it should go inside the soil that means below the dredge line will get a stable soil so if this sheet pile is large enough what will happen excess bending will occur to prevent excess bending at the other end it is retaining the soil mass so it will be connected at regular interval here if I go this is a cross section if I go in the wood direction so every per meter width you will have to provide this anchor anchor that means this is a anchor rod so it will prevent what is the function of the anchor rod once it has been put it here it will prevent the cantilever sheet pile not to bend but that means bending will be less as you provide this anchor rod so in that case at regular interval you can design and you can provide this your anchor rod so then cantilever sheet pile may be this length may be you can take larger length of cantilever sheet piles so here stability stability will be taken care of sheet pile lateral earth resistance lateral earth resistance lateral earth resistance then lateral earth resistance if you look at this how this stability has to be calculated once this is a anchored sheet pile one head this is your dredge line so it will be it will be by means of earth pressure it will be by the soil and here the pressure taken by the anchor rod both is your governing criteria for the stability of anchored sheet pile now next phase is your how what are the materials of the sheet piles has been used then again anchored sheet pile again classified as two parts one is your free earth support free earth support other is your fixed earth fixed earth support free earth and fixed earth support if I classify this anchored sheet piles into two types one is free earth support and other is your free earth support in case of free earth support so free earth support that means depth of embedment is small and pile rotate at bottom tip then in case of fixed earth support depth of embedment is large depth of embedment is large bottom tip is fixed change in curvature if you look at this both anchored sheet pile free earth support and fixed earth support in case of free earth support in case of free earth support the depth of embedment is very small depth of embedment means depth of embedment below the dredge line below the dredge line this is called depth of embedment and it is very small that means it allows it allows pile rotate at bottom tip pile rotate at the bottom tip that means it will rotate at the tip of the bottom it will rotate so but in case of fixed earth support depth of embedment is very large that means depth below the dredge line it will be very large and bottom tip is fixed that means the bottom tip it is fixed neither it will rotate nor it will movement means there is no movement at the bottom tip so what will happen there is a change in curvature there is a change in curvature in the file so once it is fixed so definitely there will be a change in curvature this part is fixed change in curvature of the pile so this is a two distinct feature once I say anchored sheet pile this anchored sheet pile may be classified as free earth support as well as fixed earth support once again I am repeating in case of free earth support depth of embedment is very small and pile rotate at the bottom tip and in case of fixed earth support depth of embedment is large and bottom tip is fixed bottom tip is fixed and once bottom tip is fixed there is change in curvature change in curvature of pile or sheet piles now what are the materials used if you look at the what are the materials used the type of your material is timber one is by timber or bamboo you can provide the sheet pile another one is your reinforced concrete another is your steel sheet pile in case of timber generally once you are using the timber that means it is used for short span short span means very temporarily the timber has been used and it can take lighter lateral load and it has been used for temporary structure then in case of reinforced concrete there is a kind of tongue and group joint it has been designed for permanent structures now come back to steel pile sheet pile steel sheet pile so it has wide advantage then both this steel sheet pile so it is kind of resistance to high driving stresses relatively light weight then easy to increase the length so how it has been connected if you look at here one end of the sheet pile wall will be in this way it is a kind of ball and steel socket joint it is a kind of ball and socket joint means how it has been connected one by one if you look at this so about this is my one of the sheet pile let me explain here if you take a bigger section so this is one part of this means it will move in this direction in this directions so this is a cross sectional view once I am showing only this part that means this is a cross sectional view this sheet piles are not available like as a whole it is not available these are all kind of a piece by piece it is available once this is a piece by piece it is available you have to connect one by one by one so how the connection is there here if I look at the connection here one end will be like this other end will be like this one piece of this sheet pile wall will be a ball joint at the regular interval other piece of the sheet pile will be a socket joint so this is a ball and socket joint so in this condition what happened even if there is a pressure it will not disintegrate it will not disintegrate with each other it will connect perfectly with each other so that there will not be any disintegration of the sheet pile walls there will not be any disintegration of the sheet pile walls if you look at the types there are three types timber reinforced concrete and sheet pile walls come back to timber timber generally use particularly in case of village if you look at here there is a river passing in the village what happened they provide timber near the river shore near this river shore so what will happen providing the timber so if there is a boat is here people can come so this timber has been used particularly for a short span for temporary purpose and maximum lightly lateral load can be taken here lateral load how it will be exerted this lateral load will be exerted by means of ship or boat because it has to tied up and people can come out from the boat so in case of this timber lighter lateral load that means only man made boats can be provide this lighter lateral load it cannot take heavy lateral loads and it is a temporary structure that means two years three years or maximum for five years kind of things this timber type of material has been provided and second part is your reinforced concrete if you look at this reinforced concrete it is a large and it is a kind of large structures and it has been used for particularly permanent for dock and harbour structures you need to have this reinforced concrete material over a period of time say twenty twenty five year or fifty year in that case reinforced concrete structures you provide permanently so that one end ship will come but and people can come out so this is also for permanent structures and another one is your steel structure steel steel sheet piles this steel sheet piles has wide advantage than timber as well as reinforced steel piles so steel sheet piles is resistance it has a resistance to high driving stresses that means it will take more stress in terms of driving you can drive inside and relatively light weight you can take it from one end to other end because it is relatively light weight and easy to increase the length what happen r c c is a reinforced concrete structure is a massive one so while installation you need lot of manpower machinery work but in case of steel sheet pile it is easy you put place one by one then go ahead so the preference wise generally is steel sheet piles are preferred rather than reinforced concrete sheet piles bamboo or timbers it is a short one and short span for temporary structure generally it has been used so these are all three types of materials generally used particularly your sheet piles now come to next part cantilever sheet pile one is your free sheet pile other is your cantilever sheet pile now as I said last class last lecture if this is your cantilever sheet pile for granular soil we can we can see the analysis of the stability analysis of we will start with this first is your cantilever sheet pile then anchored sheet pile first is your cantilever sheet pile with your granular soil cantilever last class I started with this cantilever sheet pile first is your granular soil cohesion less soil so in this case for granular soil there is a point of rotation assumptions also we have discussed earlier there is a point of rotation here is your horizontal low this point of rotation is called fiber point and once it is moving down this is your passive resistance passive state rather you can say that passive state and this part is your active state similarly in case of point of rotation this is your passive state and this is your active state and this is called dredge line so now we go for analysis step by step so let us start with this below the dredge line up to this below the dredge line up to point o that is called fiber point how the analysis how the analysis is there this is my point o this is your point of rotation if I remove all if I remove all point o this is my point of rotation these are the dotted lines above point of rotation if you look at the above point of rotation this is your this step is your passive this is your active that means pressure above point o this side will be more as compared to the side case one what I am doing I am doing it making the stability analysis step by step for granular soil this is my fiber point point o above this what are the forces coming below this what are the forces coming then we will super impose each other then we will find it out what is the capacity because you have to know what is that resistance then once you know the resistance how much load it can take then it has to be predicted based on that you can say that whether it is a stable or unstable so the pivot line if I write it to x 0 and this is your k p line and this is your k a line that means active earth pressure line this is your passive earth pressure line so this will be your somewhere else p p x somewhere else it will be your p a x so this will be x and this entire distance up to which it has been driven either small d or capital D this is the depth of amendment below this so this is point o pivot point above the point of rotation similarly now you come back to below the point of rotation below the point of rotation where is your passive this side is your passive that means force will be more and this side will be your active so that means below the pivot point this is the point o this is k p line this is your k a line now we will explain in details this physics behind it it will take time may be next class.