隧道开挖扰动对古滑坡稳定性的影响分析

Analysis on influence of tunnel excavation disturbance on stability of ancient landslide

山区地形复杂,当隧道必须在一定位置穿越古滑坡这一不良地质时,隧道的施工以及运营对古滑坡都存在着很大的威胁。隧道开挖对古滑坡稳定性的影响是施工安全必须考虑的重点问题。针对隧道-古滑坡正交体系,基于二次回归正交组合试验设计,在局部强度折减法的基础上,提出一种隧道开挖对古滑坡稳定性影响的分析方法。由于古滑坡的变形与其稳定性之间具有一定的内在联系,应用该方法建立隧道开挖后滑带最大位移拟合公式,并结合室内大型直剪试验,依据局部强度折减法的原理,研究分析隧道开挖扰动对古滑坡稳定性的影响。通过工程实例计算分析表明,该方法具有一定的有效性。

Because of the complex terrain in mountainous area,when the tunnel must pass through bad geology in a certain position,the construction and operation of the tunnel have a great threat to the ancient landslide.The influence of tunnel excavation on the stability of ancient landslide is a key issue that must be considered in construction safety.Aiming at the tunnel-ancient landslide orthogonal system,based on the quadratic regression orthogonal combination test design and the local strength reduction method,an analysis method for the influence of tunnel excavation on the stability of ancient landslide was proposed.Because of the inherent relationship between the deformation of the ancient landslide and its stability,this paper applies the method to establish the displacement formula of the sliding zone after tunnel excavation,and combines the indoor large-scale direct shear test,to analyze the influence of tunnel excavation disturbance on the stability of ancient landslide on base of the local strength reduction method.Finally,the engineering example calculation analysis shows that the method has certain effectiveness.