지진 시 George Massey 침매터널의 거동에 관한 연구

Abstract

The George Massey immersed tunnel passes the Fraser River near Vancouver, Western Canada. The tunnel was founded on sandy soils and its behavior during earthquake was analyzed by an effective stress constitutive model called UBCSAND. This model is able to calculate pore pressure rise and resulting tunnel movements due to cyclic loading. Centrifuge tests conducted at Rensselaer Polytechnic Institute (RPI) were used to verify the model performance. The centrifuge tests consisted of 2 models: Model 1 was designed for an original ground condition, Model 2 for a ground improvement by densification. In Model 1, large deformation of the tunnel was observed due to liquefaction of surrounding soil. Because of the densified zones around the tunnel the vertical and horizontal displacements of the tunnel in Model 2 was 50% less than Model 1. Measured excess pore pressures, accelerations, and displacements from centrifuge tests were in close agreement with the predictions of UBCSAND model. Therefore, the model can be used to predict seismic behavior of immersed tunnels on sandy soils and optimize liquefaction remediation methods.