冲击荷载作用下海积软土的动力释水规律研究

Law study of dynamic discharge water of marine soft clay under impact loading

通过真三轴试验,研究冲击荷载作用下海积软土的孔隙水压力、轴向变形等动力响应特征。利用热失重法和理论计算法,分析试验前后软土中结合水含量。研究表明,冲击荷载作用前后含水率变幅为15.6%~23.5%,结合水含量变幅为17.6%~29.4%,体积增大系数为2.1%~9.5%,冲击荷载作用下饱和软土的排水固结作用明显;试验前后软土中结合水含量变化较大,冲击荷载作用下软土的动力释水不同于静力作用下的释水规律;影响软土动力释水的主要因素有初始含水率、结合水含量、孔隙比、土的状态、动荷载大小和加载方式等。最后,总结出冲击荷载作用下海积软土动力释水规律和对工程设计的启示,该研究可为动力排水固结法的设计提供参考。

Dynamic response characteristics including pore water pressure, axial strain of marine soft soil under impact loading are studied through triaxial test. Bound water content of saturated soft clay is obtained by thermal gravimetric analysis and theoretical calculation method before and after triaxial experiments. Research shows that water content ranged from 15.6% to 23.5%, bound water content ranged from 17.6% to 29.4%, volume coefficient is 2.1%-9.5% before and after under impact loading. Drainage consolidation of saturated soft clay is obvious, variation of bound water content is large before and after under impact loading. The law of dynamic discharge water of marine soft soil is different from law of static discharge water. The results reveal that main factors are initial water content, bound water content, void ratio, state of soil and loading mode. Finally, the law of dynamic discharge water of marine soft soil and its inspiration is summarized. The study results can provide reference for engineering design of soft soil foundation treatment.