锦屏隧洞深部大理岩动力扰动力学特性试验研究  

Experimental study on mechanical properties under dynamics disturbance condition of marble of Jinping deep tunnel

作　　者：李邵军[1] 徐怀胜 晏飞[1] 黄翔 周济芳 LI Shaojun;XU Huaisheng;YAN Fei;HUANG Xiang;ZHOU Jifang(The State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China;The University of Chinese Academy of Sciences,Beijing 100049,China;Yalong River Hydropower Development Co.,Ltd,Chengdu 610051,China)

机构地区：[1]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,湖北武汉430071 [2]中国科学院大学,北京100049 [3]雅砻江流域水电开发有限公司,四川成都610051

出　　处：《中南大学学报（自然科学版）》2021年第8期2669-2676,共8页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(U1765206,51979268);湖北省自然科学基金创新群体项目(ZRQT2020000114)~~。

摘　　要：为研究在不同荷载条件下的隧洞岩石在动力扰动时的力学特性,基于霍普金森压杆(SHPB)系统耦合一套预加静载装置,对锦屏隧洞大理岩进行动态冲击断裂实验,探究在不同预加静载情况下,大理岩冲击荷载动力学特性及其静载对冲击破坏的影响。研究结果表明:加载过程的应力最大点往往滞后于应变最大点。因此,该试验系统得到的动拉伸强度比实际强度偏大;锦屏大理岩动态拉伸强度与冲击荷载加载速率之间呈正相关,且静载每增加1 MPa,大理岩动态拉伸强度减小约2 MPa;动压缩强度在加载速率较小时受静载影响较小,当加载速率较高时,静载10 MPa时动压缩强度最大,静载20 MPa时居中,无静载时最小;大理岩动拉伸强度受静态拉伸强度、预加静载和加载速率三者影响,其与静态拉伸强度和预加静载呈线性关系,与加载速率成一定的指数函数关系。In order to study the mechanical characteristics of tunnel rocks under different load conditions and dynamic disturbances, the dynamic impact fracture experiment on the marble of Jinping tunnel was carried out to explore the dynamic characteristics of the marble and the impact of static load under different pre-loading conditions based on the split Hopkinson pressure bar(SHPB) system coupled with a set of preloaded device. The results show that the maximum stress point often lags behind the maximum strain position during the loading process. Therefore, the dynamic tensile strength obtained by the test system is larger than the actual strength. The dynamic tensile strength of Jinping marble is positively correlated with the impact of loading rate, and the static load is increased by every 1 MPa, the strength is reduced by about 2 MPa. The dynamic compressive strength is less affected by the static load when the loading rate is small. When the loading rate is high relatively, the dynamic compressive strength is the largest under a static load of 10 MPa, 20 MPa is in the middle, and 0 MPa is the smallest. The dynamic tensile strength of marble is affected by static tensile strength, static preload and loading rate, and the fitting analysis model shows that it has a linear relationship with static tensile strength and static preload, and has an exponential function relationship with loading rate.

关 键 词：锦屏隧洞 深部大理岩 动力扰动 拉伸强度 加载速率 

分 类 号：TU45[建筑科学—岩土工程]