基于声发射的倾斜软硬互层岩石破坏特性研究

为研究深部矿井中常见的软硬互层岩石的破坏特性，结合声发射技术对红砂岩和混凝土组合的软硬互层岩石试样进行了单轴压缩试验。对单轴压缩试验现象和数据进行分析，对试样的破坏模式进行了分类，给出了软硬互层岩石峰值抗压强度随软层倾角变化的N型曲线。对声发射数据进行分析，结果表明：（1）软层倾角大小对软硬互层岩石的稳定性有显著影响；（2）软硬互层岩石软层倾角增大时，更容易诱导裂纹密集生成从而导致失稳破坏；（3）软硬互层岩石发生失稳扩展的频次随着倾角的增加呈现先增加后减少再增加的规律；（4）随着倾角的增大，剪切裂纹占比呈现先增加后降低再增加的规律。

Study on Failure Characteristics of Inclined Soft and Hard Interbedded Rocks Based on Acoustic Emission

With the economic development，people’s demand for deep resource mining is increasing day by day.Underground projects are more and more frequently carried out in deep，and deep mining of metal mines has gradually become the norm.Soft and hard interbedded rocks generally exist in deep mines.Compared with ordinary rocks，they are more prone to destabilization and failure under disturbance and stress.Therefore，it is of great significance to study the failure characteristics of soft and hard interbedded rocks.In this paper，combined with acoustic emission technology，uniaxial compression tests were carried out on the soft and hard interbedded rock samples with dip angle composed of red sandstone and concrete，and the collected acoustic emission data，such as acoustic emission number，acoustic emission rate，b value，AF-RA value，were processed and analyzed.The conclusions are as follows：（1）According to the influence of dip angle on the failure mode of soft and hard interbedded rock，it can be divided into four categories，namely axial failure，soft layer failure，interface slip and Splitting failure.（2）When the dip angle of soft and hard interbedded rocks changes from 0 ° to 90 °，the peak compressive strength curve presents a N-shaped change.（3）Based on the classification method of rock failure process proposed by Boyce and the cumulative acoustic emission number，the failure process of soft and hard interbedded rocks with different dip angles is classified.（4）The dip angle of the soft layer has a significant influence on the stability of the rock.（5）When the dip angle of the soft layer increases，the area with high acoustic emission rate will move backward and narrow，and the cracks are more likely to occur intensively，leading to instability and failure.（6）In the process of uniaxial compression，the state of instability propagation is affected by the inclination angle，which increases first，then decreases，and then increases with the increase of the inclination angle.（7） With the increase of the dip angle，the proportion of shear cracks in the failure process of soft and hard interbedded rocks increases first，then decreases，and then increases again.The research results can provide reference for solving the engineering problems of soft and hard interbedded rocks.