【作者】 楚俊；

【导师】 杨永杰；

【作者基本信息】 山东科技大学 ， 工程力学， 2008， 硕士

【摘要】 矿井灾害如冒顶、突水、冲击地压、煤与瓦斯突出等的发生与岩体的失稳破坏密切相关,而声发射（微地震）是岩体破裂前给出的重要前兆信息,在实验室内进行岩石压缩破坏声发射试验、运用声发射信息预测岩石破坏失稳对于采用声发射（微地震）监测技术预测及预防因岩石破裂引起的矿山井下灾害事故具有重要理论及实际意义。课题采用MTS815.03电液伺服岩石试验系统和SDAES-6型声发射仪,对田庄矿16煤顶板灰岩进行了室内基础力学性质试验、单轴压缩条件下的声发射试验及数值模拟研究。通过单轴压缩变形破坏的声发射试验,发现岩石的受压变形破坏过程与其内部原生裂隙的压密、新裂隙的产生、扩展、贯通等演化过程密切相关,其声发射特征较好地反映了岩石的变形破坏和损伤演化特性。同时验证了岩石声发射Kaiser效应点只存在于岩石弹性阶段的结论,Kaiser效应点记录了岩石先前受到应力的最大值,本次试验中3个灰岩试件记忆的最大应力分别是试件所受极限应力的45.5%、47.5%、45.2%。采用RFPA^2D对岩石变形破坏和损伤演化特性进行数值模拟所得结果与试验结果基本吻合,数值模拟得到的声发射Kaiser效应点为第19步,载荷为597.4N,记忆的最大应力为岩石极限应力的48.7%。对试验所得到的声发射参数时间戽列提取最大Lyapunov指数,证实采用声发射参数描述的岩石压缩破裂演化系统的未来变化趋势不是完全呈现依赖于初值的混沌状态,是可以预报的。通过离散小波系数分解,将不同尺度不同阶段上声发射事件数、能量的负的Lipschitz指数α的第一个极值所对应的轴向应变作为确定Kaiser效应点的轴向应变点,第二个极值所对应的轴向应变作为预测破裂点的轴向应变点,与实验结果比较吻合,本次试验中灰岩试件的声发射破裂预测结果表明,3个试件预测的岩石破裂轴向应变点对应的时间分别比实际破裂时间提前了4秒、5秒、5秒,预测误差在6%-10%之间。同时利用Kaiser效应法和应力解除法测试唐口煤矿-1000m水平西翼大巷三维地应力,两者结果对比分析得到最大主应力之比为1.07,中间主应力之比为0.83,最小主应力之比为0.75,两种方法测试结果比较接近。说明采用声发射Kaiser效应法得到的岩体地应力测试结果比较可靠,一般可以满足工程需要。更多还原

【Abstract】 The happening of mine disasters such as roof fall, water burst, rock burst and coal and gas outburst is closely related to the instability and fracture of rock, and acoustic emission (microseismic) is important precursor information of rock fracture. In laboratory, carrying out compressive acoustic emission experiment and using AE information to predict rock’s fracture and instability are of important theoretical and actual meanings for adopting acoustic emission (microseismic) monitoring technology to predict and prevent mine disasters caused by rock fracture.Adopting electro-hydraulic servo testing system MTS815.03 and acoustic emission system SDAES-6, laboratory fundamental mechanical property experiment, acoustic emission experiment and numerical simulation about roof limestone No. 16 coal seam of Tianzhuang Colliery were researched in this paper. Through uniaxial compression acoustic emission experiment, discovered that, the compressive fracture rock is closely related to its closing of initial crack, produce, expansion and transfixion of new crack, and its acoustic emission characteristic well reflected the fracture and damage evolving characteristic. Meanwhile, the conclusion that rock acoustic emission Kaiser Effect point only exists in the elastic stage of deformation. Kaiser Effect point can remember the maximum stress suffered before, in this experiment, the maximum stress of 3 limestone samples’ suffered before are 45.5%, 47.5%, 45.2% of ultimate stress respectively. And the results of numerical simulation to rock’s deformation fracture and damage evolvement process was basically consistent with that of experiment. The Kaiser Effect point gained through numerical simulation is at 19th step, the loading is 597.4N, and remembered maximum stress is the 48.7% of ultimate stress of rock.Extracting maximum Lyapunov exponent from time series of AE parameters gained through experiment, certify that, the movement trend of compressive fracture evolving system of AE parameters is predictable, because it isn’t in complete chaotic state that dependents on initial value. Form wavelet coefficient analysis, take two axial strains corresponding with backwards and forwards negative extremum of Lipschitz exponent a of AE events and energy as Kaiser Effect point and predicting fracture point. In this experiment, the predicting fracture time corresponding with predicting fracture strain point of 3 limestone samples was advanced 4, 5 and 5 seconds than actual fracture time respectively, and the predicting error is in the range of 6%-10%.From surveying the horizontal initial stress of horizontal west roadway of Tangkou Colliery at -1000m with Kaiser Effect method and stress relief method, the results of two methods was contra contrastive analyzed, obtained that, the ratio of maximum principle stress is 1.07, that of intermediate principal stress is 0.83, and that of least principle stress is 0.75, so, the results of two methods was close to each other. So, initial stress of rock mass surveyed through Kaiser Effect method is credible, and it can satisfy the engineering need generally.更多还原