土-上盖一体化地铁车站结构耦合作用下振动台试验研究

Experimental Study on Shaking Table Test under Structure Coupling Action of Integrated Underground Station with Soil and Upper Cover

为研究上盖一体化地铁车站结构的地震响应规律,以轨道交通地上-地下一体化结构体系和单体地铁车站结构体系为研究对象,开展了粉细砂场地振动台试验研究.分别从加速度和应变两方面对地铁车站结构部分进行地震响应研究,并将两种试验结果进行对比.试验结果表明:1)上盖一体化地铁车站结构振动台试验模型土体和结构相同监测点的加速度峰值随着输入地震强度的增加逐渐增大,而加速度放大系数则逐渐减小,测点加速度沿埋深的变化规律与地震动类型有关;2)上盖一体化地铁车站结构的拉应变幅值随着地震强度的增加呈逐渐增大的趋势,模型中柱端部的拉应变幅值最大,侧墙次之,楼板最小;3)上盖一体化地铁车站结构的加速度和应变均小于单体地铁车站结构,其中,加速度变化规律大致相同,应变幅值差异随着地震强度的增加逐渐增大,而差异增幅呈现逐渐减小并收敛的趋势.

In order to study the seismic response law of the subway station structure with integrated superstructure,based on the above ground underground integrated structure system of rail transit and single subway station structure system,the shaking table test of silty sand was carried out.The seismic response of subway station structure is studied from the acceleration and strain,and the results are compared with each other.The results show that:1)with the increase of seismic intensity,the acceleration peak of soil and the structure increases gradually,while the acceleration amplification coefficient decreases gradually.The variation law of acceleration along the buried depth is related to the type of ground motion;2)with the increase of seismic intensity,the amplitude of tensile strain of the integrated superstructure gradually increases.In the model,the amplitude of tensile strain at the end of the column is the largest,followed by the side wall,and the floor shows the smallest value.3)The acceleration and strain of the integrated subway station structure are smaller than that of the single subway station structure,while the acceleration variation law is similar.With the increase of seismic intensity,the difference of strain amplitude gradually increases,while the difference increase show the gradual decrease and converge trend.