煤岩组合体分级循环加卸载力学特性的实验研究  

Experimental research of mechanical properties on grading cycle loading-unloading behavior of coal-rock combination bodies at different stress levels

作　　者：朱卓慧[1,2] 冯涛[2] 宫凤强[1] 叶洲元[2] 喻智[2] 

机构地区：[1]中南大学资源与安全工程学院,湖南长沙410083 [2]湖南科技大学能源与安全工程学院,湖南湘潭411201

出　　处：《中南大学学报（自然科学版）》2016年第7期2469-2475,共7页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51274095;51204068);煤炭资源与安全开采国家重点实验室开放研究基金资助项目(13KF06)~~

摘　　要：使用MTS815岩石力学实验系统,对煤岩组合体进行单轴分级循环加卸载实验,对煤岩组合体在分级循环加卸载实验条件下的力学特性进行分析。研究结果表明:在单轴分级循环加卸载实验条件下,煤岩组合体破坏以剪切破坏机制为主;与单轴抗压强度实验结果相比,在单轴分级循环加卸载作用下,煤岩组合体内部微观裂纹得到扩展,试样的整体强度降低,试样破坏更彻底;在分级加卸载过程第1阶段中,煤岩组合体单循环应变曲线及能耗曲线呈现先骤然下降然后平缓下降的趋势,初始应力与耗散能和应变呈现正相关关系。To research the mechanical properties of coal-rock combination bodies under multistage and cyclical loading-unloading, a multistage and cyclical uniaxial loading-unloading test （consisting of repeated loading and unloading） was conducted by using the MTS815 System. The resuks show that the shear failure is the main failure type occurring in the coal-rock combination bodies under multistage uniaxial cyclical loads. Crack propagation in the coal-rock combination bodies under multistage cyclical loads reduces the overall strength of the samples, resulting in more severe fhilure than in uniaxial compression test. At the first stage of the testing, the strain curve and energy dissipation crave of the samples for a single cycle tend to drop sharply and then go into a slower decline. Moreover, the initial stress shows a positive correlation with dissipate energy and strain.

关 键 词：煤岩组合体 分级循环加卸载 整体强度 耗散能 

分 类 号：TU45[建筑科学—岩土工程]