Computer modeling of the limit state of a slab foundation with regard to the rigidity of the above-foundation structure

Abstract

The task of this research is to determine the values of the generalized strength parameters of the foundation soil and , at which the depth D Z of the development of Coulomb areas of plastic deformation under the edges of the foundation of finite rigidity thickness Н , loaded with a uniformly distributed load of variable intensity q and foundation of the same thickness, bearing a rigid above-foundation structure of variable height H * will correspond to the closure of plastic area under the base of the foundation what is complied with the ultimate state of the foundation (according to Prandtl). To carry out computer modeling a list of variables of design parameters that influence the process of formation and development of plastic areas under the sole of the foundation, and the intervals of their change, has been established. As a result of the calculations and processing of the data obtained it was found that the numerical values of and differ significantly from each other: equations of approximating curves of dependencies of the form have different forms correspondingly and are described by the different approximating expressions. If it is given the values of the generalized strength parameters of the foundation soil and , which the soil mass should have after its fixing, then using the graphs shown in Fig. 6-10 and the table it will be possible to conclude whether the limit state of the fixed soil base will be achieved under given loads. In other words, focusing on the numerical values of and , it is possible to determine the values , which must be obtained in the process of fixing the soil base so that the specified external load does not exceed the maximum permissible value.