Dynamic Response Analysis of Docking Chamber Structure Considering Viscoelastic Boundary Condition

Spring-damper units were set on the boundaries to absorb incident waves and reflected scattering waves to realize viscoelastic artificial boundary (VAB). The equivalent node load input method was used to simulate the VAB and viscoelastic boundary element wave input. Programming is based on APDL secondary development language with ANSYS finite element software. Considering the interaction between chamber structure and the surrounding soil, docking chamber structure dynamic model is established based on the VAB. The linear elastic model was used for concrete structure. The D-P nonlinear model was used for the back soil calculation. Docking chamber structure dynamic analysis under conditions of fixed boundaries and viscoelastic boundaries were conducted. The result indicated that under the viscoelastic boundary conditions, dynamic acceleration response is significant on the top of the lock wall, which is approximately 2.5 times of the value on the bottom of the lock wall. The maximum response stress appears near the cross point of the lock wall and the bottom floor with value of approximately 5620 kPa;.The chamber bottom floor is subjected to tension and maximum stress with the value of approximately 6180 kPa. Usually, the structure response under the fixed boundary conditions is higher than the structure response under the viscoelastic boundary conditions.