剪切速率对平直充填节理的剪切力学特性影响研究

发布时间：2018-05-27 03:34

本文选题：充填节理 + 动态剪切　；参考：《岩土力学》2017年07期

【摘要】：不同剪切速率下充填节理的剪切特性对动态荷载作用下工程岩体的安全稳定性有着重要的影响。为了研究剪切速率对充填节理的剪切力学特性的影响,通过花岗岩试块中间充填天然河砂模拟充填节理。采用RMT-150C电伺服试验机进行直接剪切试验,研究了法向压力、剪切速率和充填厚度对充填节理的剪切力学特性的影响。试验结果发现,充填节理的剪切应力-位移曲线属于屈服剪切型,分为弹性阶段、过渡阶段和滑移阶段,无明显峰值强度,在滑移阶段剪切应力继续增加,增加速率与法向压力大小有关。随着剪切速率的增加,充填节理的剪切强度和内摩擦角略有增加。为了考虑充填节理剪切应力-位移关系的非线性变化过程,采用双曲线形式对弹性阶段的应力-位移曲线进行拟合,结果较好,并提出初始剪切刚度和刚度影响系数描述其变形特性。剪切速率和法向压力的增加会大幅度增加初始刚度,充填厚度对两个参数的影响与法向压力有关。对于无起伏度的平直节理,剪切速率和充填厚度对剪切强度影响较小,但对充填节理的变形特性有重要的影响。
[Abstract]:The shear characteristics of the filling joints under different shear rates have an important influence on the safety and stability of the rock mass under dynamic loading. In order to study the effect of shear rate on the shear mechanical properties of the filling joints, the RMT-150C electric servo test machine is used to simulate the filling joints of the natural river sand in the middle of the granite test block. In the shear test, the effect of normal pressure, shear rate and filling thickness on the shear mechanical properties of the filling joints is studied. The results show that the shear stress displacement curve of the filling joint belongs to the yield shear type, which is divided into the elastic phase, the transition stage and the slip stage have no obvious peak strength, and the shear stress continues to increase in the slip stage. Adding, the increase rate is related to the size of the normal pressure. With the increase of the shear rate, the shear strength and the internal friction angle of the filling joints increase slightly. In order to take into account the nonlinear change process of the shear stress displacement relation of the filling joint, the stress displacement curve of the elastic phase is fitted with the hyperbolic form, and the results are better, and the initial results are put forward. The initial shear stiffness and stiffness influence coefficient describe its deformation characteristics. The shear rate and the increase of normal pressure will greatly increase the initial stiffness. The influence of the filling thickness on the two parameters is related to the normal pressure. For the straight joint without undulation, the shear rate and the filling thickness have little effect on the shear strength, but the deformation of the filling joint is deformed. Characteristics have an important impact.
【作者单位】：武汉理工大学道路桥梁与结构工程重点实验室;中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;
【基金】：国家自然科学青年基金(No.51609183);国家自然科学基金(No.51274157) 岩土力学与工程国家重点实验室资助课题(No.Z015005)~~
【分类号】：TU45

【相似文献】