砂岩球体法向恢复系数实验研究

发布时间：2018-01-21 07:50

本文关键词： 砂岩球体法向恢复系数尺寸效应速度效应　出处：《爆炸与冲击》2017年05期 　论文类型：期刊论文

【摘要】：法向恢复系数是岩崩块石运动分析的关键参数,其取值直接决定了块石的运动轨迹。本文中采用自行设计的碰撞实验装置和声频采样技术,测定了砂岩球体碰撞的法向恢复系数,研究了粒径、碰撞速度、含水状态和板的弹性特性4个因素对恢复系数的影响。结果表明:砂岩球体法向恢复系数存在复杂的尺寸效应,恢复系数随粒径的增大先增大后减小;碰撞过程中存在的黏弹性耗能机理和弹塑性损伤耗能机理共同作用产生了复杂的尺寸效应;受砂岩非均质特性的作用,粒径较小时,恢复系数的速度效应较明显(随速度增大而增大),粒径较大时速度对恢复系数的影响消失;砂岩饱和使黏弹性耗能和弹塑性损伤耗能增加,使恢复系数比风干时低;等效弹性模量对恢复系数的影响较大,等效弹性模量越大,法向恢复系数越小。
[Abstract]:Normal recovery coefficient is the key parameter of rock avalanche mass movement analysis, and its value directly determines the movement track of rock mass. In this paper, the self-designed collision experimental device and audio sampling technique are adopted. The normal recovery coefficient of sandstone sphere collision was measured and the particle size and impact velocity were studied. The results show that the normal recovery coefficient of sandstone sphere has complex size effect, and the recovery coefficient increases first and then decreases with the increase of particle size. The joint action of viscoelastic energy dissipation mechanism and elastic-plastic damage energy dissipation mechanism in collision process leads to complex size effect. Due to the effect of sandstone heterogeneity, the velocity effect of recovery coefficient is obvious when the particle size is small (increasing with the increase of velocity, and the effect of velocity on recovery coefficient disappears when the particle size is larger; When sandstone is saturated, viscoelastic energy dissipation and elastic-plastic damage energy consumption are increased, and the recovery coefficient is lower than that of air drying. The effect of the equivalent elastic modulus on the recovery coefficient is greater, and the greater the equivalent elastic modulus is, the smaller the normal recovery coefficient is.
【作者单位】：武汉大学土木建筑工程学院;
【基金】：国家自然科学基金项目(41272342);国家自然科学基金面上项目(41772308)
【分类号】：O313.4
【正文快照】： 岩质边坡崩塌是自然界中常见的地质灾害之一,对山区的公路、桥梁、铁路、房屋建筑等构成了严重威胁[1-3]。对于易发生岩崩的地区来说,崩塌的块石体积以及块石在边坡上的运动轨迹直接决定了岩崩是否对基础设施构成威胁,以及威胁的大小。影响岩块运动轨迹的关键在于岩块与边坡碰

【相似文献】