土-混凝土接触面剪切破坏模式分析

Analysis of shear failure mode for clay-concrete interface

通过对红黏土与混凝土结构进行大型直剪实验,对其剪切过程进行数值模拟,分析了红黏土与混凝土结构接触面的破坏形式。试验结果表明:剪应力-剪位移曲线表现为折线型和双曲线型,分别对应于接触面在剪切过程中存在的滑移破坏和弹塑性破坏2种不同形式,随着混凝土表面粗糙度的增大,接触面的剪切破坏由滑移破坏逐渐向在土体内部形成剪切滑动带的破坏过渡。数值分析结果表明:法向应力较小时,剪切破坏形式主要表现为滑移破坏;随着法向应力的增加,逐渐转变为向土体内部形成剪切滑动带的破坏;并且在相同法向应力作用下,随着接触面粗糙度的增加,土体内部形成的剪切滑动带的厚度增加。

The shear failure modes for clay -concrete interface were analyzed by large scale direct shear test and numerical simulation.The test results show that the shapes of shear stress -shear displacement curves are broken line or hyperbolic line,respectively.Corresponding to sliding failure or elastoplastic failure of the interface in two different forms during shearing,it is found that with the increase of the roughness of concrete surface,the sliding failure gradually transits to the failure formed shear slide zone in the soil.The numerical results reveal that the shear failure mode of contact surface is mainly sliding failure when normal stress is low.With the increasing nor-mal stress,the shear failure mode is the failure in the soil.The thickness of shear slip bands formed in the soil becomes bigger when roughness of contact surface increases.