富溪双连拱隧道出口高边坡稳定性评价及支护效果分析

富溪双连拱隧道出口高边坡岩体风化、卸荷严重,在施工开挖前边坡中上部已经发生较为明显的倾倒变形,整个变形体处于极限平衡状态。本文在现场调查和岩体结构分析基础上,建立了边坡变形破坏机理的概念模型,利用FLAC3D模拟研究了开挖后坡体变形特征。在变形分析基础上,提出了对倾倒变形体采用锚管注浆处理的边坡治理措施,支护效果模拟计算表明,注浆后边坡稳定性较好,同时监测资料也显示支护措施实施后,边坡的稳定性较好,可以保障公路的施工和长期营运的安全。

STABILITY ASSESSMENT AND SUPPORT EFFECTIVENESS OF HIGH PORTAL SLOPE FOR A TWIN-ARCHED TUNNEL IN FUXI TOWN, ANHUI PROVINCE

The rock masses comprising the slope at the portal of a twin-arched tunnel in the town of Fuxi, Anhui province are strongly affected by weathering and unloading. Before excavation, the slope had noticeable down-slope deformation at its middle and upper levels and the deofrmation was in the state of limit equilibrium. On the basis of the site investigation and the study of the rock mass structures, the paper esbalishes the deformation mode and failure mechanism of the slope. Furthermore, the paper simulates the deformation character FLAC3D. The deformation analysis leads the design measure that uses grout to stabilize the rock masses. The result of calculations indicates that the slope can have better stability after grouting. In the meanwhile, the monitored data also shows that the stability of the grouted slope is better than that of the slope before grouting. This can ensure that the expressway will be safe during the road construction and its long-term usage.