水对灰质泥岩隧道围岩稳定性影响研究

Influence of water on the stability of surrounding rock in lime mudstone tunnel

在灰质泥岩隧道施工过程中,水会导致围岩岩石的物理化学性质发生变化,进而对隧道围岩的稳定性有着重要的影响。基于金盆弯隧道现场的监控量测数据,通过分析雨季和非雨季时相同埋深、相同地质情况下隧道段面的围岩与初期支护之间的压力、初期支护钢支撑的应力及隧道拱顶沉降结果,确定了水作用下,围岩与初期支护之间应力随时间的变化情况、初期支护内力随时间的变化情况以及拱顶沉降随着时间的变化情况。并通过有限元数值模拟软件ABAQUS,模拟隧道开挖后,在有水和无水环境下围岩横向和竖向位移的变化,得到:水的存在导致隧道围岩的拱顶沉降增大,拱腰及边墙收敛增大,进而分析水对围岩的稳定性的影响。通过对比分析拱顶沉降的数值模拟结果与现场监控量测结果,可以看出两者的沉降变化规律相吻合,验证了模型的合理性,从而进一步更改完善施工、设计方案,来保证隧道的安全施工,同时也为今后研究水对围岩岩石性质及围岩稳定性影响的机制提供了参考。

During the construction of lime mudstone tunnel,physical and chemical properties of surrounding rock would be changed by water.So it plays an important role in stability of surrounding rock in the tunnel of lime mudstone.Based on monitoring results of Jin Penwan tunnel,the influence of water on the change of stress with time between the rock and the initial support,the change of stress with time within the rock and the change of vault settlement with time is investigated by analyzing the surrounding rock pressure,steel support stress and vault settlement result.The result about the presence of water leads to increase of vault settlement,horizontal convergence of haunch and side wall is confirmed by simulating the surrounding rock under the environment of water and without water with ABAQUS.The rationality of model is verified by comparing numerical results with monitoring results,which provides certain help to improve the construction plan and design scheme,and ensure the safety of tunnel construction,providing a reference for future studies on the mechanism of the rock nature and the stability of surrounding rock.