Calculation Method of Seismic Residual Displacement of Sheet Pile Quay Walls

Sheet pile quay walls have widely been used in port engineering, hydraulic engineering, and civil engineering, but the sheet pile quay is a flexible retaining structure, which undergoes large deformation during earthquakes. The seismic design methods of the sheet pile quay wall in different countries are greatly different, and there is deficit of studies performed on the seismic residual displacement of the sheet pile quay walls. Based on the pseudostatic method and the calculation method for obtaining the dynamic earth pressure of clay soil, it is assumed that the cantilever part of the sheet pile quay wall bears the dynamic active earth pressure and the part in deep soil bears dynamic passive earth pressure on the side of the sea and bears dynamic active earth pressure on the side of the ground. The hydrodynamic pressure acting in front of the wall is calculated using Westergaard’s approach. The displacement of the front wall of the sheet pile quay is calculated, respectively, according to the upper part and lower part of mud surface. Based on the deflection curve differential equation and boundary conditions, the calculating formulas on seismic residual displacements of the sheet pile quay walls are derived and the proportional displacement method for determining the tension force of the pull rod is given. Combining with an engineering case, the theoretical calculation results are compared with the ADINA simulation results, and comparison results show that these two calculation methods are close under the mud, but they have little difference in the calculation results of the part above the mud because of the proportional displacement method of the tension force of the pull rod.