逆断层控制带含煤地层地应力分布规律  

In-situ stress distribution law in coal-bearing stratum under control of reverse fault

作　　者：王晓东[1,2] 罗永江[1,2] 石佳林 梁运培[1,2] 胡千庭[1,2] WANG Xiaodong;LUO Yongjiang;SHI Jialin;LIANG Yunpei;HU Qianting(State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044,China;School of Resources and Safety Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400044 [2]重庆大学资源与安全学院,重庆400044

出　　处：《煤炭学报》2024年第9期3918-3931,共14页Journal of China Coal Society

基　　金：宁夏回族自治区重点研发计划资助项目(2022BEG02015)。

摘　　要：为深化对逆断层控制下含煤地层的地应力分布特征的认识,运用自主研发的大型真三轴仪器“矿山地质构造模拟实验系统”,基于相似原理,开展考虑深度、断层倾角、落差等影响因素的物理模拟实验。结合数值模拟,分析不同条件下扰动区宽度和地应力分布规律。研究结果表明:①断层上盘的应力扰动宽度大于下盘,且2者都随深度的增加而减小。倾角45°断层的扰动宽度比60°断层小,在500、1000、1500 m深度处,前者分别为35.72、27.33、10.71 cm,后者分别为47.03、32.15、17.85 cm。②临近断层处最大水平应力(σ_(H))有明显的应力集中现象。当断层倾角大于45°时,倾角越大,应力集中程度越大。45°断层下盘临近断层处的4号测点在500、1000、1500 m深度的应力集中系数分别为为0.95、0.94、1.15,与区域应力场接近。而60°断层的4号测点在500、1000、1500 m深度的应力集中系数分别为1.11、1.44、1.42。③在远离断层处的未受扰动区,σ_(H)偏转角度较小,几乎都小于15°。在扰动区,σ_(H)偏转角度受倾角控制,σ_(H)偏转角度最大达到约90°。倾角45°断层中,σ_(H)偏转角度最大的区域在下盘临近断层处;在倾角60°断层,这一区域则出现在距离断层有一定距离的上盘中。④当落差大于煤层厚度时,扰动宽度(尤其上盘扰动区宽度)明显变大。应力集中区域出现在弹性模量更大的地层中,煤层中各测点σ_(H)离散性很大。To deepen the understanding of the distribution characteristics of geostress in coal-bearing stratum under the control of reversed faults,physical simulation experiments based on the similarity principle were conducted using a selfdeveloped large-scale true triaxial instrument called the“Mine Geotectonic Simulation Experiment System”,with consideration for depth,dip angle,and fault drop.In conjunction with numerical modeling,we examine the disturbance width and the geostress's distribution law in various scenarios.The results show that:①The geostress disturbance width in the hanging wall is greater than that in the footwall,and both of them diminish as depth increases.The 45°fault has a narrower disturbance width than the 60°fault.At 500,1000,and 1500 m depth,the former is 35.72,27.33,10.71 cm,and the latter is 47.03,32.15,and 17.85 cm,respectively.②A clear instance of the maximum horizontal stress(σ_(H))at nearby faults concentrating stress.The greater the dip angle,the greater the concentration of stress,when the angle is greater than 45°.At 500,1000,and 1500 meters depth,the stress concentration coefficients of the No.4 measurement stations at the 45°fault’s footwall are 0.95,0.94,and 1.15,which are close to the regional stress field.These of 60°fault are 1.11,1.44,and 1.42,respectively.③Far from the fault,in the undisturbed zone,theσ_(H)deflection angle is nearly less than 15°.The greatest deflection angle in the disturbed zone is around 90°,and is governed by dip angles.The maximum deflection angle appears close to the footwall fault in 45°fault,but it appears farther away from the hanging wall fault in 60°fault.④The width of the disturbance is clearly greater when the drop is greater than the coal seam’s thickness,particularly in hanging walls.In greater elasticity modulus strata,zones of stress concentration are found,and each measurement site in the coal seam has a very largeσ_(H)dispersion.

关 键 词：地应力分布 含煤地层 逆断层 应力集中 应力转向 

分 类 号：TD712[矿业工程—矿井通风与安全]