单轴压缩下含水砂岩强度损伤及声发射特征  

Strength deterioration and acoustic emission characteristics of water-bearing sandstone in uniaxial compressive experiment

作　　者：姚强岭[1] 李学华[1] 何利辉[1] 周健[1] 

机构地区：[1]中国矿业大学矿业工程学院,深部煤炭资源开采教育部重点实验室,江苏徐州221116

出　　处：《采矿与安全工程学报》2013年第5期717-722,共6页Journal of Mining & Safety Engineering

基　　金：国家自然科学基金青年基金项目(51304208);国家自然科学基金项目(51374197);江苏高校优势学科建设工程项目

摘　　要：宁东煤田主采煤层顶板广泛分布含水砂岩,该层砂岩受采动影响易于变形失稳。通过实验室试验,定量分析了含水砂岩组分,研究了其烘干、吸水随时间变化规律。研究发现该含水砂岩富含黏土矿物,砂岩分别烘干和浸水6 h后含水率变化趋于稳定,且随着含水率增加该砂岩单轴抗压强度和弹性模量呈指数函数减小。声发射试验结果表明:干燥状态下,含水砂岩声发射计数峰值与应力峰值相对应,而随着含水率增加,声发射计数峰值较应力峰值位置滞后,呈现出"延迟"特征,并据此提出了预测预报该类砂岩顶板稳定的技术思路。Water-bearing sandstone is widely distributed in the roof of primary mining coal seam of Ningdong coal field, which is prone to deformation and instability. In this experiment component of water-bearing sandstone is quantitatively analyzed, and time relationship between drying and water suc- tion of sandstone is also studied. Research shows that this kind of sandstone is rich in clay minerals, and the variation of moisture content tends to keep stable six hours after being dried and soaked respectively; moreover, uniaxial compressive strength and elastic modulus of the sandstone decrease on the scale of exponential function with the increase of moisture content. The results of acoustic emission characteris- tics experiment show that count peak of acoustic emission of sandstone samples corresponds to the peak stress under the condition of being dried and lags behind with the increase of moisture content which shows ＂delaying＂ characteristics; in the mean time, pulse count decreases significantly with the peak of energy. According to these, technical thoughts are put forward to predict and forecast the stability of such kind of sandstone roof.

关 键 词：单轴压缩 含水砂岩 强度损伤 声发射特征 

分 类 号：TD353[矿业工程—矿井建设]