This paper presents a case study on the impact of jointed rock mass deformation on liner stability for an inclined excavation at the Bulianta Coal Mine. The tunnel was excavated by a single shield tunnel boring machine (TBM), with part of the excavation passing through a heavily jointed rock mass at great depth. Serious local instabilities occurred at one side of the liner due to highly asymmetric loading caused by large ground stresses and joint deformation. A support system with anchored cables and compressible mortar was combined with segmental lining to overcome these instabilities. With this case as a baseline, some numerical sensitivity analyses were performed to study how the ground might have responded to different combinations of support. The results show that an appropriately anchored cable system was able to limit the propagation of the asymmetric deformation of the jointed rock mass and significantly reduce the degree of anisotropy and the magnitude of the loads on the liner. The use of compressible mortar between the liner and the jointed rock mass further lowered the anisotropy of the load on the liner. There are optimum values for the rock bolt length and the compressible mortar thickness, beyond which these parameters have limited effects on the behaviour of the system. The combined effect of compressible mortar and anchor cables in promoting ground and liner stability is greater than the sum of the two individual support effects. These results clearly demonstrate that the combination of anchored cables and compressible mortar had a significant positive effect on the overall support system stability.

中文翻译：

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节理岩体分段衬砌联合支护体系：以补连塔煤矿斜井隧道为例

本文以补连塔煤矿倾斜开挖为例，研究节理岩体变形对衬管稳定性的影响。隧道是由一台单盾构隧道掘进机 (TBM) 开挖的，部分开挖过程穿过了一个很深的严重节理的岩体。由于大的地应力和接头变形引起的高度不对称载荷，在衬管的一侧发生了严重的局部不稳定性。带有锚索和可压缩砂浆的支撑系统与分段衬里相结合，以克服这些不稳定性。以这种情况为基准，进行了一些数值敏感性分析，以研究地面可能如何响应不同的支撑组合。结果表明，适当锚固的缆索系统能够限制节理岩体不对称变形的传播，并显着降低各向异性程度和衬管上的载荷大小。在衬砌和节理岩体之间使用可压缩砂浆进一步降低了衬砌上载荷的各向异性。锚杆长度和可压缩砂浆厚度存在最佳值，超过这些参数对系统行为的影响有限。可压缩砂浆和锚索在促进地基和衬砌稳定性方面的综合作用大于两种单独支撑作用的总和。