中文摘要：

地铁循环荷载作用下饱和软黏土的动力特性研究对于揭示软黏土在地铁荷载下的孔压、强度以及变形模式具有重要意义,可以为控制地铁长期沉降、降低运营风险提供理论依据。试验加载形式的不同会带来不同的动力特性表征,需选取最能反映地铁列车真实性质的荷载形式。本文在列车荷载作用下研究土动力特性,采用室内动三轴试验的方法,对比分析不同形式下动力荷载作用效果。试验研究表明：偏压正弦波可以作为简化波形研究列车荷载,它不仅可以确保加载过程中地基土只有压应力,而且能较好地模拟列车循环荷载。

英文摘要：

Research on the dynamic characteristics of saturated soft soil has important significance for revealing the pore pressure,strength,and deformation mode of soft clay under subway loading.It can also provide a theoretical basis for the control of long-term settlement and the reduction of operational risk.Different forms of loading will bring different dynamic characteristic,so a study method must be identified that can reflect the true nature of subway train loads.In this study,we used the laboratory dynamic triaxial test to examine the dynamic characteristics of soil under a train load,and comparatively analyzed the effects of different dynamic loads.The results show that the biased sine wave can be used as a simplified train load wave.It also can ensure that only compressive stress exists in the soil during the process of loading,and it better simulates the cyclic loading of subways.