循环加卸载下岩石滞回环及其弹性储能机制分析  

Analysis of the hysteretic loop of rock and its elastic energy storage mechanism under cyclic loading and unloading

作　　者：张治伟 王帅锋 樊方正 ZHANG Zhiwei;WANG Shuaifeng;FAN Fangzheng(Jinjie Coal Mine,CHN Energy Shendong Coal Group Co.,Ltd.,Yulin 719315,China)

机构地区：[1]国能神东煤炭集团有限责任公司锦界煤矿,陕西榆林719315

出　　处：《陕西煤炭》2022年第5期135-143,共9页Shaanxi Coal

摘　　要：设计岩石的单轴增载荷循环加卸载实验,通过MTS伺服系统进行验证,结果表明,岩石的塑性滞回环面积随着循环加载载荷的上升整体呈现递增的趋势。在加载过程中存在着力学行为由弹性变为塑性的应力阈值,约为应力峰值的60.5%,能量耗散率与应力水平的正相关增长关系分为2个阶段,60.5%应力水平前的增长斜率明显小于60.5%应力水平后,反应了岩石在经历过弹性阶段后岩石内部的裂隙发育明显增多。重新定义了循环加卸载过程中积累弹性能量的计算方法,得出弹性储能随着循环增载荷的增大,呈现持续增长的趋势,但是在应力峰值的65%左右,弹性储能的积累有一个明显的增长趋势。可以为煤岩巷在支护参数上、工程施工上以及预测岩爆提供一定的参考参数。定义了岩石的弹性连续系数,判断岩石内部裂隙的发育程度,弹性连续系数越大,岩石内部裂隙发育越完全。研究成果可作为受载岩体稳定性分析和工程实践的理论依据。Designed a uniaxial increasing load cyclic loading and unloading experiment for rock,the experiment through the MTS servo system showed that:The area of plastic hysteresis loop of rock shows an increasing trend with the increase of cyclic loading.During the loading process,there is a stress threshold for the mechanical behavior to change from elastic to plastic,about 60.5%of the peak stress.The growth slope before the 60.5%stress level is significantly less than after the 60.5%stress level,it reflects that the development of cracks in the rock has increased significantly after going through the elastic stage.This article redefines the calculation method of accumulated elastic energy during cyclic loading and unloading,it is concluded that the elastic energy storage increases with increasing cycle load,showing a trend of continuous growth,but around 65%of the peak stress,the accumulation of elastic energy storage has a clear growth trend.It can provide certain reference parameters for coal and rock roadway in supporting parameters,engineering construction and predicting rock burst.This paper defines the elastic continuity coefficient of rock,to determine the degree of development of cracks in the rock,the greater the elastic continuity coefficient,the more complete the development of internal cracks in the rock.The research results can be used as the theoretical basis for the stability analysis and engineering practice of the loaded rock mass.

关 键 词：岩石 岩石力学 塑性滞回环 积累弹性能量 弹性连续指数 应力阈值 

分 类 号：TD315[矿业工程—矿井建设]