大砬子沟 2 号隧道出口路基边坡稳定性分析

依托大砬子沟 2 号隧道出口段路基边坡工程，运用 midas GTS NX 有限元软件计算模型分析挡土墙+喷锚支护前后应力变化特征以及水平、竖直位移变化特征。结果表明:在自然状态下，采用强度折减法（SRM）计算得出的路基边坡安全系数为 1.11，小于边坡安全系数标准值 1.35，不满足稳定性要求；经削坡和挡土墙+喷锚支护后，边坡X方向最大位移减小为 4 cm；在支护作用下，土体基本保持稳定，经强度折减法计算得出支护后的安全系数为 1.37，符合安全系数标准，可以保证边坡的安全。

Stability Analysis of Subgrade Slope at the Exit of Dalazigou No.2 Tunnel

Taking the side slope of the roadbed at the exit of Dalazigou No.2 Tunnel as a research object, the of calculation model of midas-GTS NX finite element software has been used to analyze characteristics of the stress changes and horizontal and vertical displacement changes with/without retaining wall + spray anchor support in this paper. The results show that under natural conditions, the safety factor of the tunnel entrance slope calculated by strength reduction method (SRM) is 1.11, which is less than the standard value of 1.35 and cannot meet the stability requirements. After the establishment of slope excavation and retaining wall + spray anchor support, the maximum displacement in the X direction of the slope has been reduced to 4 cm. Under the action of the support, the soil remains basically stable. The safety factor calculated by strength reduction method is 1.37 after supporting by the retaining wall and spray anchor support, which meets the safety factor standard and can ensure the safety of the slope.