结构物位移对接触面土体力学特性影响的数值模拟

Numerical Simulation of Effect of Structure Displacement on Mechanical Properties of Contact Surface

应用自主研发的试验仪对土与结构物相互作用进行试验,试验时使竖向应力和围压达到要求应力值,研究结构物以恒定速率运动时结构物位移对接触面力学特性的影响,进而利用PFC2D对土与结构物在不同位移下相互作用的试验进行数值模拟,分析了土与结构物相互作用时的剪应力变化和土体变形情况。结果表明,接触面剪应力随结构物位移的增加先快速增加,再逐渐趋缓,最后趋于稳定;结构物的剪切作用对接触面土体的影响尤为明显,对远离接触面的土体影响较小,使接触面处土体颗粒从右侧向左侧运动,导致量测圈1内土体堆积发生剪胀,剪应力值增大至140kPa,量测圈3内土体疏松发生剪缩,剪应力值减小至35kPa。

An experiment on the interaction between soil and structure are completed by using the self-developed test apparatus.During the test,the vertical stress and the confining pressure should reach the required stress value.When the displacement of structure changed with constant rate,the influence of structure displacement on the mechanical properties of contact surface was studied.Then the PFC2 Dwas used to simulate the interaction between soil and structure under different displacements.Finally,the shear stress variation and the deformation of soil during the interaction between soil and structure were analyzed.The results show that the shear stress of contact surface increases quickly along with the increase of the structure displacement,then gradually becomes slowly,and ultimately tends to be stable.The shear action of the structure has a great influence on the soil at the contact surface,which has little influence on the soil away from the contact surface.The shear action of the structure makes the soil particles move from the right side to the left side,which leads to the shear dilation in the measuring circle 1and the shear shrinkage occurs within the circle 3.What＇s more the shear stress value in the measuring circle 1increases to 140 kPa,and the shear stress value in the measuring circle 3decreases to 35 kPa.