Abstract：The safety of the bridge and its normal operation are possibly influenced when the deformation of bridge foundation is largely induced by ground consolidation and the groundwater table in the stratum under the bridge foundation is lowered. In order to predict safety and deformation of bridge foundations during precipitation，3D non-saturation seepage-stress coupling theoretical analysis model is set up；and the 3D FEM model of interaction of ground，groundwater and bridge is also set up by software ABAQUS. Based on the direct coupling analysis method，spatial responses of bridge foundations during precipitation and the dynamic changes of groundwater table are simulated. It is discovered that ground settlement is 21.37 mm and bridge foundation settlement is 19.56 mm；and differential settlement between bridge foundations is less than 2 mm under the condition of descending 10 m water table. It is also proven that the bridge foundation is safe and the existing precipitation scheme is reasonable. The simulated and measured settlement values agree well. So it is demonstrated that numerical model and analysis method are reasonable and reliable，and it can offered important guidance and reference to the study of similar problem.
