During construction lock chamber floor,in order to reduce floor internal force and avoid the generation of cracks,we usually set up wide construction joints.The floor internal force is with the emergence of the foundation settlement deformation,and the foundation deformation process is a consolidation process related to time.The permeability coefficient of consolidation settlement speed depends on the foundation of drainage and soil conditions.We study the lock chamber the Biot consolidation theory in different foundation natures and the settlement process under different loading ways,and get the internal forces under different conditions.Comparing with the internal force under the method of linear elastic slab,we determine the reasonable side load reduction factor.