深部高地应力区软岩巷道模型试验及数值优化

深部巷道围岩大变形和失稳破坏是高地应力区巷道普遍存在的问题,有效的支护措施是保证深部巷道稳定的重要因素。以淮南某煤矿深部巷道为工程背景,通过相似材料模型试验利用YDM-D多功能地质力学模型试验系统,研究了巷道在无支护和锚杆支护两种条件下巷道围岩的变形破坏特征。研究结果表明:相似材料选用粘土、水泥、砂及水,配合比为4∶1∶20∶1.3的试件表现出良好的塑性大变形特性;相似材料模型经过锚杆加固后,洞壁最大位移有所减小,由15.4 mm减小为12.1 mm,加固效果不明显,表明锚杆的间距偏大,并用数值分析方法模拟验证了试验结果。采用正交设计结合数值分析方法对淮南某煤矿深部巷道喷锚支护方案进行了优化分析。结果表明:拱顶锚杆长度间排距分别取2.4 m、0.8 m、0.8 m,边帮锚杆长度间排距分别取3.7 m、0.8 m、0.8 m,底板锚杆倾角45°,锚杆长度间排距分别取2.9 m、0.9 m 、0.8 m,喷层厚度取120 mm加固方案效果最优。

Deep Soft Rock Roadway Model Experiment and Numerical Optimization of Support in High Geo-Stress Area

Gross distortion and instability and failure of deep roadway is a universal problem in high geo-stress area, the effective reinforcement is a key factor to ensure the stability of the deep roadway. To take an deep roadway in a coal mine in Huainan Area as engineering background, a similar experiment such as YDM-D multifunction geomechanical modeling of underground structure test system to study the character of deformation of surrounding rock of roadway which are unsupported or reinforced by anchor bolt support. The results show that the mixing proportion of the sample from clay, concrete, sand and water is 4∶1∶20:1.3 and the material has plastic deformation character. Maximum displacement of cavity wall reduced after reinforcement by anchor bolt support on similar material mould, and decreased from 15.4 mm to 12.1 mm. If reinforcement effect does not apparent, it indicates that the space between anchor bolts is too large. At the same time the experiment result is verified by numerical solution. An optimum analysis for combined bolting and shotcrete project of the deep roadway of Wang Feng Gang coal mine is carried out by homogeneous design combined with numerical solution analysis method. Result shows that: row spacing of roof bolt length of the crown of arch are 2.4 m, 0.8 m and 0.8 m respectively, row spacing of roof bolt length of the edge are 3.7 m, 0.8 m and 0.8 m respectively, angle of inclination of roof bolt on bottom plate is 45°, row spacing of roof bolt length are 2.9 m, 0.9 m and 0.8 m respectively, when jetting thickness is 120 mm, reinforcing effect of the reinforcement is optimal.