基于非连续变形分析方法的深部沿空掘巷围岩变形破坏及控制机制对比研究

利用非连续变形分析方法(DDARF)对单节理锚固试件在单轴压缩条件下的变形破坏及裂隙扩展过程进行分析,并以深部厚顶煤综放沿空掘巷——赵楼煤矿11302工作面轨道巷为工程背景,应用DDARF对沿空巷道围岩的变形破坏及控制机制进行研究,同时利用地质力学模型试验及现场试验进行对比验证。重点分析了沿空巷道围岩裂隙演化规律,并定义裂隙率cR及裂隙减少率rR两个指标对DDARF计算中的沿空巷道裂隙演化规律进行定量分析。研究结果表明:采用DDARF方法对单节理试件在无锚和加锚条件下的单轴压缩试验计算与室内试验结果相吻合;对沿空掘巷过程中巷道围岩变形情况进行DDARF计算,结果显示,围岩变形呈现沿空帮>顶板>实体帮>底板的变化趋势,与模型及现场试验监测数据相符;根据cR及rR两个指标对计算得到的无锚和加锚沿空巷道围岩裂隙发育情况进行定量分析,结果显示,沿空巷道围岩破坏趋势为cI cII cIIIR?R?R,与变形趋势相一致;虽然锚固效果明显,但由于Ⅰ区、Ⅱ区本身围岩破碎严重,支护后裂隙率最大的cIR仍然是裂隙率最小的cIIIR的2.13倍,为了维护围岩稳定性,除了进行锚杆(索)非对称支护外,还应对Ⅰ区、Ⅱ区关键部位增加支护措施。DDARF方法关于沿空巷道围岩变形破坏的计算结果与实际工程相近,可有效开展裂隙演化与变形破坏机制研究,分析此类巷道的控制对策。

Comparative research on surrounding rock failure deformation and control mechanism in deep roadway driving along goaf based on discontinuous deformation analysis

(discontinuous deformation analysis for rock failure) method was used to research the roadway along goaf of 11302 workface in Zhaolou Colliery. In order to get its failure deformation and control mechanism, DDARF was first used to analyze the crack propagation of single joint anchored specimen under uniaxial compression, then the stimulation result of real roadway was compared with monitoring data from geomechanical model test and field test, to verify its correctness. The focus was on the crack evolution law of surrounding rock in the roadway along goaf. In order to quantitatively analyze the crack evolution in DDARF calculation, two indexes of (crack ratio) and (crack reduction ratio) were defined. Research results showed that the DDARF simulation results were consistent with uniaxial compression test of single joint anchored specimen. In the DDARF calculation of surrounding rock deformation in the roadway driving along goaf, it was shown that the deformation of coal side next to goaf was the largest, followed by roof and integrated coal side, floor was the least, and the monitoring data from model test and field test were both consistent with the result. According to the two indexes and , quantitative analyses was conducted to compare the crack evolution of non-anchored and anchored roadways, and the result was consistent with the deformation trend that is . As the surrounding rock had been seriously crushed, although supporting scheme was effectively, the max crack ratio with anchor supported was still 2.13 times of the . In order to maintain the stability of surrounding rock, the key parts of zoneⅠ and zone Ⅱ should be strengthened besides asymmetric supporting with anchors. For the stimulate result was closer to actual engineering, DDARF method could not only be used to research crack evolution and failure deformation, but also guide countermeasure to control these roadways effectively.