Analysis of karst protective slab foundations taking into account the features of the base modeling

Abstract

This paper presents a practical application of the improved method for calculating of slab foundations designed in karst rock areas. The method implementation is associated with the application of the updated analytical model taking into account behavior patterns of the ground base in the karst hole zone. The analytical solution obtained in the closed-form in the nonlinear formulation, allowed to obtain two key parameters of the foundation bed in the zone being studied - ? and ????. The dependence to determine the size of the weakening zone around the karst sinkhole area - ? and the developed criterion for the quantitative change of the coefficient of subgrade reaction ???? in the zone of this weakening made it possible to propose a bilinear model of the interaction of the “foundation slab - base” system. The parameters of the base weakening obtained as a result of the problem solution have a wide range of changes depending on the physical and mechanical characteristics of the base soils and can be used for engineering calculations of slab foundations designed in karst areas. The comparative analysis of the calculations made according to the proposed and normative methods showed a substantial under-reinforcement of the foundation slab projected in the karst-hazardous zone.