考虑土体密实度的钢-土界面剪切特性研究

土体密实程度对内河码头大尺寸钢护筒嵌岩桩的承载性状具有重要的影响。在一定含水率及颗粒级配条件下,控制试样土体干密度分别为1.80,1.85,1.90 g/cm3进行土体与钢板的往复剪切室内试验,探索了不同干密度条件下试样在不同法向应力条件下的剪应力-剪位移关系、极限剪切强度以及界面往复剪切的残余强度。研究发现钢-土界面的剪切过程主要有3个阶段:弹性阶段、塑性阶段和破坏阶段;极限剪切强度满足摩尔库伦准则且随干密度增大粘聚力和内摩擦角均增大,且呈线性增加;往复剪切过程中,研究剪应力的变化情况发现同方向不同循环过程中最大剪应力几乎保持不变,不同方向剪切循环过程中,负方向剪应力均比正方向稍大。

Research on shearing characteristics of steel-soil interface considering dense degree of soil

The dense degree of soil plays an important role in bearing behavior of large size rock socketed filling pile with steel tube in the inland wharf.Contact interface shearing tests are carried out under certain conditions of moisture content and grain composition with different degree of dry density of samples.The relationship between the shear stress and displacement,limiting shear strength and residual strength of reciprocating shearing under different normal stress of different degree of dry density are studied.The results show that there are three stages during the shearing process of steel soil interface including elastic stage,plastic stage and failure stage.The Mohr coulomb criterion is met by limiting the shear strength.Cohesion and internal friction angle are increased linearly with the increasing dry density.In the process of reciprocating shearing,the maximum shear stress remains unchanged of the same shearing direction in different circulations.However,the negative direction of shear stress is slightly larger than the positive direction of shear stress.