中文摘要：

采用GDS循环三轴试验、压汞分析，同时辅以电镜扫描，对上海地区地铁行车荷载作用下的饱和软黏土微观性状进行定量分析研究，获得了一系列定性、定量化的结果。研究成果表明在地铁运营相当长的一段时间内，隧道侧壁和底部地层都会存在结构单元之问的压密过程，而由于隧道底部承受来自地铁的荷载较大，压密趋势有所缓和，单元之间的错动将会是变形的主要因素。

英文摘要：

Microstructure change of saturated soft clays under cyclic loading is studied by using cyclic triaxial test, mercury intrusion porosimetry （MIP） and scanning electron microscopy （SEM）. The results show that after the subway tunnel is operational, the microstructure blocks in the soil surrounding the side wall and bottom of the tunnel would be compressed. The tendency of compaction is decreasing in the bottom soil of the tunnel because of larger subway loading, and the offset of microstructure blocks is the major form of deformation.