Long-term settlement of tunnels across a river induced by vehicle operation          

With rapid development of river tunnel engineering,long-term settlement of soft ground induced by traffic operations has caused high concerns.For the propose of analyzing long-term settlement of saturated soft clay ground under traffic loading,simplified methods based on semi-empirical models for predicting the accumulative deformations of soft clays are usually preferred.A new empirical model is proposed in order to simulate cumulative plastic strain and pore pressure of anisotropically consolidated soft clays based on undrained cyclic triaxial tests,which extends a semi-empirical formulation previously presented by the authors for isotropically consolidated clays.Unlike the previous model,a new formulation is introduced to take effects of initial K0-consolidated stress state into consideration.Parameters of the empirical model are determined based on undrained cyclic triaxial tests on anisotropically consolidated Shanghai soft clay.Based on the layer-wise summation method,a simplified method is suggested to calculate the long-term settlement of soft ground caused by traffic loading.Analysis for settlement of a typical river tunnel project is presented to demonstrate the new method