Basal Heave Stability Analysis of Deep Foundation Pit in Soft Soil

In order to avoid the limitations in traditional methods of basal heave stability analysis for deep foundation pit, numerical analysis Was adopted by establishing a two-dimensional elasto-plastic finite element model. Resistant heave stability safety factor was calculated using the fitting formula acquired from the simulated results, and then the upheaval value and plastic range under critical conditions were studied. The results show that the soil stress will be redistributed with the increasing of excavation depth until upheaval damage taken place. The upheaval value will be larger, the plastic range will be greater, and the basal heave stability will be worse with the decreasing of plastic parameters. Meanwhile, the basal upheaval peak position will transform gradually from excavation center to diaphragm neighborhood with the decreasing of plastic parameters. There is a critical value associated with supporting parameters for soil plastic parameters and the possibility of upheaval destruction increases significantly if the plastic parameters are less than the critical value.