超大型地下洞室围岩锚杆支护方式的优化设计

The optimized design of rockbolts supporting the large-scale underground cavities

锚杆支护对于超大型地下洞室的稳定性具有重要作用。考虑了初始地应力,模拟了超大型地下洞室的分级开挖和支护的过程,并通过对周围岩体的位移、塑性区及锚杆应力的变化规律的分析,总结了不同锚固方案的加固效果,进行支护方式的优化设计。结果显示,锚杆支护能有效地抑制周边围岩的应力松弛,改善周边围岩的受力特性。在工程造价固定的情况下,适当的减小锚杆的长度,加大锚杆的密度,能够更有效的控制岩体的变形和塑性区的范围。

The rockbohs have an important effect on the stability of the large-scale underground cavities. This paper takes account of initial crustal stresses, simulates the process of underground caves excavating and supporting. By analyzing the variation laws of displacements, the plastic zones of the surrounding rock and the load along the bolts, it summarizes the effects of several different bolt support plans and makes an optimized design of the support. According to the result, the bolt support can effectively restrict the relaxation of surrounding rock and reinforce the surrounding rock. When the cost of one project is fixed, shortening the length and increasing the density of the bolts appropriately can more efficiently make control of displacements of the surrounding rock and the range of the plastic zones.