地下洞室开挖数值模拟分析

The numerical analysis of excavation of large underground cavern

以某地下洞室施工为例,通过关键点小主应力及安全系数随开挖步的变化,分析了开挖对大型地下洞室群围岩稳定造成的影响,数值计算表明,开挖过程中,围岩整体稳定性较好,但是围岩小主应力随开挖步的不断递进而持续增大,关键点安全系数持续减小,局部关键点最小安全系数不满足规范要求,需及时支护,且通过支护方案比选,确定了经济合理支护方案。

Taking construction of underground cavern as example, the influence from excavation of underground cavern on the stability of sur- rounding rock was studied through such as the minor principal stress, safety factor of key point during the process of excavation. The numerical calculations show that the stability of surrounding rock is well after excavation, however, the minor principal stress are increased continuously with excavation of cavern, but the safety factor of key point is decreased continuously with excavation of cavern. The minimum safety factor of parts of key point does not satisfy the requirement of standard, and it must support for surrounding rock timely. According to supporting scheme compari- son, the economic and reasonable supporting scheme was received.