酸性矿井水作用下砂岩冲击特性变化分析  

Analysis on Impact Characteristics of Sandstone Under Acidic Mine Water

作　　者：龙钰 韩文梅[1] 关学锋[1] 何天明 杜龙飞 葛彦鑫 LONG Yu;HAN Wenmei;GUAN Xuefeng;HE Tianming;DU Longfei;GE Yanxin(School of Science,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学理学院,山西太原030051

出　　处：《中北大学学报（自然科学版）》2022年第5期460-466,共7页Journal of North University of China(Natural Science Edition)

基　　金：山西省自然科学基金资助项目(201901D111142)。

摘　　要：处于地下的岩石材料长时间与酸性矿井水接触后,其稳定性会发生变化,对施工安全性造成一定的威胁.以白砂岩作为研究对象,在硫酸溶液作用后采用分离式霍普金森压杆(Split hopkinson pressure bar,SHPB)实验系统对其进行动态冲击试验,并利用高速摄像机捕捉整个冲击过程,得到了不同工况下白砂岩动态冲击的应力-应变曲线及环向应变.研究结果表明:各应力-应变曲线没有明显的压密阶段,线弹性阶段也不明显,在应力峰值前后阶段形成一个塑性平台;在相同的应变率下,各工况试件应力极值点排序为σ_(H7-0)>σ_(H4-10)>σ_(H4-20)>σ_(H2-10)>σ_(H2-20).在单轴压缩下,岩石微元受到张拉破坏,且溶液酸性越强,浸泡时间越久,砂岩环向应变峰值越低;砂岩的破坏模型为带有径向膨胀的劈裂破坏,且破坏程度与溶液酸度及浸泡时长呈正相关.The stability of underground rock will be changed in the acid water for a long time,and it takes a serious threat to the safety of construction in the underground.Taking the white sandstone as the research object,the dynamic impact test was conducted by split hopkinson pressure bar(SHPB)experimental system,and the whole impact process was captured by a high-speed camera.The stress-strain curves and circumferential strains of the specimens under different conditions were obtained.The results show that the densification stage and the linear elastic stage are not obvious in each stress-strain curve and the plastic platform stage is formed before and after the stress peak.The order of stress peak of specimens under various working conditions isσ_(H7-0)>σ_(H4-10)>σ_(H4-20)>σ_(H2-10)>σ_(H2-20).Under uniaxial compression,the rock elements are damaged by tension.And the more acidic the solution is,and the longer the soaking time is,the lower the circumferential strain peak is.The failure model of sandstone is split failure with radial expansion,and the degree of failure is correlated with solution acidity and soaking time positively.

关 键 词：酸性溶液 霍普金森压杆 矿井 环向应变 破坏模式 

分 类 号：TU458[建筑科学—岩土工程]