深部缓倾斜软岩巷道非对称变形机理及稳定性控制研究

发布时间：2018-05-26 22:19

本文选题：深部 + 软岩　；参考：《太原理工大学》2015年硕士论文

【摘要】：煤矿进入深部开采后，在复杂地应力场的影响下，深部岩体呈现出非线性力学行为，深井巷道围岩的大变形及稳定性控制问题越来越突出[1]。而针对深部缓倾斜软岩巷道非对称变形破坏，其支护形式通常采用对称支护，由于支护体力学特性与围岩力学特性的不耦合，围岩首先在关键薄弱部位发生破坏，进而导致整个巷道的失稳。若提高全断面支护强度，满足周边高应力破坏严重部位的支护强度，而对破坏变形较小的部位采用同等的支护强度会造成支护成本的增加，材料的浪费等问题。因此充分掌握深部缓倾斜软岩巷道非对称变形机理，确定其支护关键部位，，提出有效的支护对策是非常必要的。本文以新安煤矿+535回风石门为研究背景，通过现场工程地质调查、理论分析、数值模拟以及现场工业性试验相结合的方法分析了深部缓倾斜软岩巷道非对称变形的机理，研究了水平应力的方向、大小及围岩产状对深部缓倾斜软岩巷道非对称变形的影响作用。在此基础上提出了“关键部位加强支护”的非对称耦合支护对策，并在新安煤矿进行了工业性试验研究。主要结论如下：（1）通过现场观测及数值模拟分析表明，深部缓倾斜软岩巷道呈现出非对称变形特征为底臌偏向高帮，顶板下沉量偏向顶板左侧（低帮）、高帮位移量大于低帮的特征。（2）在不考虑岩层倾角对软岩巷道非对称变形影响下，采用数值模拟软件FLAC3D对最大水平主应力方向与巷道轴向夹角(0°、15°、30°、45°、60、°90°)对巷道非对称变形的影响进行了分析。（3）在不考虑最大水平主应力方向与巷道轴向夹角对巷道非对称变形的影响下，对不同侧压系数下缓倾斜软岩巷道非对称变形特征进行了数值模拟研究，分析了其对非对称变形的影响作用。（4）基于FLAC3D内置的cvsic黏弹塑性本构模型对深部缓倾斜软岩巷道围岩破坏过程进行了数值模拟分析，结合现场观测，将该类巷道的变形特征总结为：巷道围岩整体来压→底板非对称底臌→右帮中下部内挤变形→左帮中上部变形→顶板左侧破坏→不对称变形扩大→巷道整体失稳。（5）通过对缓斜软岩巷道岩层产状、应力场及数值模拟研究结果分析，确定了新安煤矿+535回风石门巷道非对称变形破坏的关键部位为巷道低帮肩角、高帮部位及高帮底角。（6）采用“关键部位加强支护”的非对称耦合支护对策对新安煤矿+535回风石门巷道进行了工业性试验研究，通过现场观测表明该技术能够有效地控制该类巷道的变形。
[Abstract]:Under the influence of complex ground stress field, the deep rock mass presents nonlinear mechanical behavior after the coal mine enters into deep mining. The problems of large deformation and stability control of surrounding rock in deep roadway are more and more prominent [1]. In view of asymmetric deformation and failure of soft rock roadway with gently inclined depth, symmetrical support is usually used in the support form. Because of the uncoupling between the mechanical properties of support and surrounding rock, the surrounding rock is destroyed in the key position at first. This will lead to the instability of the whole roadway. If the full section support strength is improved to satisfy the support strength of the serious site with high stress around it, the same support strength will cause the increase of the support cost and the waste of the material. Therefore, it is very necessary to fully understand the asymmetric deformation mechanism of soft rock roadway in depth, determine the key parts of support, and put forward effective supporting countermeasures. In this paper, the mechanism of asymmetric deformation of deep gently inclined soft rock roadway is analyzed by means of field engineering geological investigation, theoretical analysis, numerical simulation and field industrial test. The effect of horizontal stress direction, size and occurrence of surrounding rock on asymmetric deformation of soft rock roadway with gently inclined depth is studied. On the basis of this, the asymmetric coupling support countermeasures of "strengthening support in key parts" are put forward, and industrial test research is carried out in Xinan Coal Mine. The main conclusions are as follows: 1) through field observation and numerical simulation analysis, it is shown that the deep soft rock roadway is characterized by asymmetrical deformation of floor heave and roof subsidence to the left side of roof (low slope, high slope displacement is larger than low slope). 2) without considering the influence of rock dip angle on the asymmetric deformation of soft rock roadway, the influence of maximum horizontal principal stress direction and the axial angle of roadway on the asymmetric deformation of roadway is analyzed by using the numerical simulation software FLAC3D (0 掳/ 15 掳/ 30 掳/ 45 掳/ 60, 掳90 掳). 3) without considering the influence of maximum horizontal principal stress direction and the axial angle of roadway on the asymmetric deformation of roadway, the characteristics of asymmetric deformation of gently inclined soft rock roadway under different lateral pressure coefficients are numerically simulated. Its effect on asymmetric deformation is analyzed. (4) based on the cvsic viscoelastic-plastic constitutive model built in by FLAC3D, the failure process of surrounding rock in soft rock roadway with gently inclined depth is simulated and analyzed, combined with field observation. The deformation characteristics of this kind of roadway are summarized as follows: the whole surrounding rock of the roadway is compressed with asymmetric floor heave and the middle and lower part of the right side is extruded and the middle and upper part of the left side is deformed and the left side of the roof is destroyed. Based on the analysis of rock formation, stress field and numerical simulation results of soft rock roadway with gentle slope, it is determined that the key site of asymmetric deformation and failure of 535 return wind Shimen roadway in Xinan Coal Mine is low shoulder angle, high top position and high bottom angle of roadway. In this paper, the asymmetric coupling support countermeasure of "strengthening support in key position" is used to study the industrial test of 535 return air Shimen roadway in Xinan Coal Mine. The field observation shows that the technique can effectively control the deformation of this kind of roadway.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD353

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