基于不同应力释放作用下小线间距隧道开挖地表沉降规律的研究

隧道开挖常常伴随着开挖面周围岩体应力的释放,而应力释放的大小与开挖面的大小、岩体的性质、地下水的埋深等多个因素密切相关。因此,在进行隧道开挖数值模拟计算时,初步估计开挖面岩体应力释放大小显得尤为重要。基于此,并结合工程实例,研究了不同应力释放下小线间距隧道开挖地表沉降规律,并与实测沉降数据相结合加以分析。结果表明,开挖面应力释放为60%时,数值模拟结果与实测结果较为接近,更能合理反映工程实际。

Surface Subsidence Law of Small Line-Spacing Tunnel Excavation Based on Different Stress Release Action

The release of surrounding rock stress around excavation face is often along with the excavation of tunnel. The degree of released stress is closely related to the area of excavation surface, the properties of rock, the depth of groundwater and other factors. Therefore, during the numerical simulation of tunnel excavation, the preliminary estimate of the degree of rock stress release at excavation face is particularly important. Based on the situation and combined with a practical project, the earth surface subsidence law during small line-spacing tun- nel excavation under different stress release is studied. Combining with it, the measured subsidence data are also analyzed. The result shows that when the stress release scale on excavation surface reaches 60%, the numerical simulation result is quite closes to the measured result, which can reflect the actual project more reasonably.