CAJ | 학술논문

断裂岩石在长期地质力学作用下发生蠕变，并伴有声发射，此声发射规律可为岩石稳定性监测和预警提供有益借鉴。为了研究断裂岩石蠕剪过程的声发射特征，在法向力恒定的条件下，对巴西拉破坏和压剪破坏2种不同形式的断裂砂岩进行蠕变分级剪切试验，并运用全信息声发射信号分析仪进行实时监测，得到2种不同破坏形式的断裂岩石在不同蠕剪阶段声发射能量和蠕变剪切位移关系。同时，利用声发射定位系统对蠕剪过程中断裂岩石的双翼啮合和磨损进行定位，结合断裂面等高线图，预测断裂岩石在长期蠕剪中的破坏位置和破坏形式。试验结果表明：断裂岩石蠕剪失稳前声发射信号缺失；巴西拉破坏岩样蠕剪中后期声发射能量出现波峰，每段剪切位移加载前期能量达到局部最大值，之后呈现下降趋势；压剪破坏岩样蠕剪中期声发射能量出现低谷，每段剪切位移加载中期声发射能量出现局部波峰。同时，由声发射定位可知，2类断裂岩石啮合面中心部位都最先发生破坏，断裂面蠕变剪切的初期破坏具有方向性，破坏初期沿断裂面呈现带状分布并与剪切方向垂直。
단렬암석재장기지질역학작용하발생연변，병반유성발사，차성발사규률가위암석은정성감측화예경제공유익차감。위료연구단렬암석연전과정적성발사특정，재법향력항정적조건하，대파서랍파배화압전파배2충불동형식적단렬사암진행연변분급전절시험，병운용전신식성발사신호분석의진행실시감측，득도2충불동파배형식적단렬암석재불동연전계단성발사능량화연변전절위이관계。동시，이용성발사정위계통대연전과정중단렬암석적쌍익교합화마손진행정위，결합단렬면등고선도，예측단렬암석재장기연전중적파배위치화파배형식。시험결과표명：단렬암석연전실은전성발사신호결실；파서랍파배암양연전중후기성발사능량출현파봉，매단전절위이가재전기능량체도국부최대치，지후정현하강추세；압전파배암양연전중기성발사능량출현저곡，매단전절위이가재중기성발사능량출현국부파봉。동시，유성발사정위가지，2류단렬암석교합면중심부위도최선발생파배，단렬면연변전절적초기파배구유방향성，파배초기연단렬면정현대상분포병여전절방향수직。
Under a long-term geomechanical loading,creep deformation would occur in fractured rocks, accompanying with acoustic emission(AE). The laws of AE are meaningful to monitor and warning of the rock in stability. In order to look into the AE features of fractured rocks during creep shear,the direct creep shear experiment of fractured rocks induced by compressive shear and Brazilian tension was carried out under constant normal force. AE technology was used to detect the acoustic events during the creep shear. The relationship between AE energy and creep shear displacement at different loading stages is revealed. Meanwhile,the locations of the interlocks and the micro-contact fractures are also identified the laser scanned contour maps of the fractured rock surfaces by the AE events. The experiment shows that there is a signal blank phenomenon of AE events before the instability occurs. Regarding to the fractured rocks induced by Brazilian tension,the peak of AE energy mainly appears at the middle and late stages of the creep shear process,and AE energy reaches local maximum at the early stage of each loading followed with its downward trend;for the fractured rocks induced by compressive shear,AE energy valley appears at the middle stage of the creep shear process,and at each shear loading a small peak of AE energy appears at the middle stage. In addition,AE position detection shows that the micro-contact fractures mainly occur first at the central part of the interlocked surfaces. The initial micro-contact fractures present a directional character that a zonal distribution develops perpendicular to the shear direction at early loading stages.