桥隧过渡结构对边坡稳定性影响分析

当隧道洞口处于边坡坡面上时，隧道开挖亦对边坡的稳定造成影响，而当隧道与桥梁相连时，其过渡结构对边坡的影响更加复杂。以某隧道桥梁连接工程为实例，利用有限差分法，建立了桥隧过渡结构处的二维与三维数值模型。在二维情况下，着重研究了边坡的整体稳定性问题，包括单个与多个滑动面下的边坡的安全系数，以及极限状态下边坡剪应变以及水平位移分布。而三维情况下，分析了隧道洞门施工对附近坡体表面位移的影响，以及边坡局部滑移面的变化规律。结果表明，在保证边坡整体稳定性的前提下，桥隧过渡结构对边坡表面位移及局部稳定性有重要影响。

Influences of Tunnel-bridge Section on Slope Stability

When the tunnel portal is located on the slope, the tunnel excavation is also has influ- ence on the slope excavation. This influence will be more complicated when tunnel and bridge were adja- cent. Taking a tunnel-bridge section engineering as example, with finite different method, the numerical model of tunnel portal and front slope in 2D＆3 D condition was built. In 2D condition, the overall stabili- ty of slope was analyzed, including the safety factor of front slope under single and multiple sliding sur- faces and the distribution of shear strain and horizontal displacement was obtained. In 3D condition, the effect of excavation and construction to displacement on slope surface was analyzed, also the change law of local sliding surface with different foundation form. The result show that when the overall stability of slope is guaranteed, the tunnel-bridge section has great effect on slope surface displacement and local stability.