交通荷载引起的静偏应力对饱和软黏土不排水循环性状影响的试验研究

Study on effect of traffic loading induced static deviator stress on undrained cyclic properties of saturated soft clay

为研究交通荷载引起的静偏应力对饱和软黏土的不排水循环性状的影响,设计了室内不排水动三轴试验,将动应力简化为静偏应力与正弦荷载的叠加,研究了静偏应力对饱和软黏土变形、孔压发展规律以及动强度的影响。研究表明,静偏应力对土体动力特性影响很大,加快了塑性变形、残余孔压发展,降低了动强度曲线,减小了最小极限循环强度。且静偏应力的影响随着静偏应力的增大而显著。研究结果说明,交通荷载引起的动应力作用下,饱和软黏土更容易破坏。

In order to study the effect of traffic loading induced static deviator stress on the undrained cyclic properties of saturated soft clay, an undrained cyclic triaxial test was designed. The cyclic loading was simplified as sine wave plus static deviator stress. And the effect of static deviator stress on deformation, pore pressure and cyclic strength of soft clay was studied. It was found that the static deviator stress greatly affected the cyclic properties of soft clay. The development of plastic deformation and residual pore pressure was accelerated, the cyclic strength curve lowered and the minimum limited cyclic strength was reduced. And its effect increased with the increasing of static deviator stress. It was shown that saturated soft clay was easier to fail under traffic loading induced dynamic stress.