Abstract An alarming settlement has been observed during the operation of transport infrastructures built on soft clay areas. Considering the long duration of traffic load, analyzing the long-term cyclic behavior of saturated soft clay considering different drainage conditions is of considerable significance. In this study, a series of cyclic triaxial tests were conducted on undisturbed soft clay from Wenzhou under the partially drained and undrained conditions, respectively. The test results reveal that: (a) more permanent strain was generated of the soft clay specimen under partially drainage condition, which is due to the volume change caused by both the decrease of void ratio and the shape deformation of specimens; (b) under partially drained condition, the resilient strain and hysteretic loops both exhibit a sudden increase in strain due to transient softening induced by excess pore water generated in the early stage followed by a reduction until a steady value is attained; (c) it is obvious that the allowable cyclic stress ratio (CSR) under undrained condition is larger than that under partially drained condition, indicating that considering partially drained condition is necessary in practical engineering design.

中文翻译：

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不同排水条件下饱和软粘土的长期循环行为

摘要 在软粘土地区建造的交通基础设施运行过程中观察到了令人震惊的沉降。考虑到交通荷载持续时间长，分析不同排水条件下饱和软粘土的长期循环行为具有重要意义。在这项研究中，分别在部分排水和不排水条件下对温州原状软粘土进行了一系列循环三轴试验。试验结果表明：(a) 部分排水条件下软粘土试件产生更多的永久应变，这是由于孔隙率降低和试件形状变形引起的体积变化；(b) 在部分排水的情况下，由于早期产生的过量孔隙水引起的瞬时软化，弹性应变和滞后环都表现出应变的突然增加，然后减少直到达到稳定值；(c) 不排水条件下的许用循环应力比（CSR）明显大于部分排水条件，说明在实际工程设计中考虑部分排水条件是必要的。