 Hi everyone, myself, Nagraj Kuppa, assistant professor in civil engineering department, Vulture Institute of Technology, Solapur. In the present video lecture, I am going to teach about bearing capacity of soil. So these are the learning outcomes. At the end of this session, student will be able to explain definition of bearing capacity of soil and its relevant definition and also explain modes of failure in the foundation. So these are the contents included in the video lecture. Now definition of bearing capacity of soil sample. Bearing capacity, the word bearing is nothing but power, power of soil sample. So in the, in this particular picture, so this is related to foundation soil. So when we are constructing foundation just below the structure, so above this structure it is, we are calling it as structure, below this structure we are calling it as foundation. Foundation is nothing but it is a part and parcel of soil sample. It means if a soil sample is good, then the life of foundation is also good. Now come back to the definition. The bearing capacity of soil is nothing but it is a maximum contact pressure between the foundation and soil which should not produce a shear failure in the soil. It means here it should not produce any shear failure at the base of footing. Now important terminology is related to soil bearing capacity. First one, ultimate bearing capacity which is designated by QU or Qultimate. It is a maximum pressure that foundation can withstand without undergoing shear failure. It means in this particular figure, so this entire red color line is indicating shear failure line. Now it is a foundation, P2 is nothing but overburden pressure, P1 is nothing but weight of superstructure which is in downward direction, therefore total weight which is acting at beneath the foundation P equal to P1 plus P2. Now second definition, net ultimate bearing capacity. Net ultimate bearing capacity is nothing but which is increasing the pressure at the base of foundation that cause shear failure of soil. It means which is causing shear failure at the beneath the foundation, therefore QNU which is QNU equal to QU minus QU minus gamma into DF where gamma is nothing but unit weight of soil sample and DF is nothing but depth of footing. Now net safe bearing capacity which is designated by QNS it is nothing but it is a net pressure which the soil can carry a without exceeding allowable settlement. It means net net is nothing but the net safe bearing capacity is mainly which is occurring due to the weight of superstructure. Come back to the fourth definition, safe bearing capacity of soil sample. Normally we are calling this definition as a SBC of soil sample. It is nothing but it is a safe extra pressure. In addition to existing load a ground can withstand in a for ground can withstand in longer time. Luckily we are calling it as SBC therefore SBC equal to design load divided by area of footing. Here this is nothing but area of footing and P1 is nothing but design load. Therefore design load divided by area of footing is nothing but it is SBC which is in terms of kilo Newton per meter square or 10 per meter square. Let us come back to once again types of shear failure in the footing or else we are also we can call it as modes of failure in the footing. Basically there are three types of failure in the footing general shear failure, local shear failure and punching shear failure. So these are the corresponding figures which are related to general shear failure, local shear and punching shear failure. General is nothing but here first I will explain the figure. So this entire curvilinear upward line is nothing but bulging line this footing from footing to ground level line is nothing but failure or slip edge line. Particularly it is of occurring in all type of soil sample and if friction angle is greater than 36 degree this condition this type of failure will happen. And the failure plane it is fully well defined and bulging is occurring in between footing and ground sample. Now bulging on the ground surface adjacent to the footing it means here bulging is adjacent to the adjacent to the foundation and it is a quite common type of shear failure in all type of soil sample and also occur in the relatively strong soil sample. It means already I have explained if 5 value is greater than it means shear strength or angle of shear resistance is greater than 36 degree then this condition of shear failure occurs in the soil. Now local shear failure so in this figure bulging offers from foundation to ground level in well defined condition but here it is not well defined. It means almost it is linear inclined line it means it is not in well defined condition and even slip edge line is also not connecting to bulging line. It means sometimes it may jerk inside the soil sample. It means these two failures these two failures are nothing but once again tilting failures punching punching is nothing but I will give a best example we are punching the papers we are punching the papers is nothing but we are pressing the papers even here also same here the foundation is pressing inside the soil sample. It means which is go inside the soil sample with linear amount this condition punching shear failure occurs in angle of resistance less than 28 degree. Now this figure it is first zone second zone and third zone particularly first zone this particular triangular figure is indicating active zone passive zone and shear zone even here also same active zone passive zone and shear zone. So it is right side figure it is pressure also settlement curve for A it is related to general shear failure B is related to punching local shear failure and C is related to punching shear failure. It means in the general shear failure soil will take high amount of pressure and less amount of settlement occur in the soil and also in B also same it is also taking high amount of load and less amount of settlement particularly in C already I said this condition see punching local shear failure occurs in loose state of soil sample therefore it will take less amount of load and high amount of settlement will occur. So now I will pause the video and think and answer this questions. So these are the correct answers related to suggested questions in correct answer first for first question correct answer is edge of footing and ground surface. So of course it is edge of footing to edge of footing to ground surface it is a correct answer for first question already I have explained for second also. So 35 degree sorry 35% is correct answer density index if it is lies between means almost less than 35% it is for punching shear failure. So these are the presumptive analysis which is based on the experiment sand experience they have suggested some values for SBC as per Indian standard chart 1904 1978 type of material safe bearing capacity type of material rock soft rock coarse sand medium sand fine sand soft shale or stiff clay soft clay and very soft clay and its corresponding SBC value 3242 once again up to 50 kilo Newton per meter square. So these are the references which I referred for this video lecture thank you.