格鲁吉亚公路隧道放坡位置优化

Optimization of Slope Cutting Position of the Georgian Highway Tunnel

为了在保持山体稳定性的前提下减少隧道施工的成本,文章依托格鲁吉亚公路隧道工程,提出在开挖隧道过程中,在保证山体稳定的情况下,通过将山体放坡前移4 m以减少山体开挖量的方案,并对这两种方案利用数值分析软件MIDAS进行数值模拟,对比分析了原始方案和放坡前移方案两种工况下的山体地应力、隧道初期支护应力和边坡沉降情况。结果表明,将山体放坡前移后,山体地应力峰值减小,初期支护受到的剪应力减小,边坡沉降与原方案相比基本一致,总体来说拱顶的沉降值减小,拱底隆起值增加了2 mm。在以后的隧道施工中,可根据相应的地质条件适当将放坡面前移,以减少对山体的开挖量,节约成本。

In order to reduce the cost of tunnel construction on the premise of maintaining the stability of the mountain,based on the Georgia highway project,this paper proposes a optimization scheme to reduce the excavation volume of the mountain in the process of tunnel excavation by moving the slope forward by 4 m,under the condition of ensuring the stability of the mountain.The in-situ stress of the mountain,the stress of the initial support of the tunnel and the settlement of the slope before and after optimization are analyzed by numerical simulation with software MIDAS.The results show that:after the slope is moved forward,the peak value of in-situ stress of the mountain decreases,the shear stress of the initial support decreases,and the slope settlement is basically consistent with that of the original scheme,generally speaking,the settlement of the vault decreases and the uplift value of the arch bottom increases by 2 mm.Therefore,according to the corresponding geological conditions,the slope can be appropriately moved forward to reduce the amount of mountain excavation and save costs in the future tunnel construction.