乌沙隧道出口滑坡成因分析及治理工程设计

Analysis on Genesis of Landslide at the Exit of Wusha Tunnel and the Treatment Design

隧道开挖常常诱发仰坡及侧面边坡滑动破坏,严重影响公路建设的施工安全。以汕昆高速公路乌沙隧道出口滑坡为例,采用传递系数法计算了该滑坡的稳定性,并重点分析了仰坡滑坡和右侧滑坡的相互作用关系。结果表明:隧道区复杂的地形、工程地质条件、松散破碎的易滑地层、不利的软弱结构面等是滑坡形成的内因;降雨入渗作用和隧道仰坡开挖是滑坡形成的外因。对仰坡滑坡和侧面滑坡重叠部分的稳定性分析,应按照深层滑面和浅层滑面的计算结果,选取较小值(最不利稳定性结果)进行计算。根据计算结果,采用抗滑桩、异形桩间挡板、钢管桩和管棚等措施进行综合治理,取得了良好的效果。

Tunnel excavation often induce front and side slope sliding, endangering highway construction seriously. Taking the landslide at the exit of Wusha Tunnel along Shantou-Kunming Highway as an example, transfer coefficient method is used to calculate the slope stability with the interaction between the front and right side landslide to be analyzed emphatically. The landslide is formed by both internal causes, including the complex landform in the tunnel area, engineering geological conditions, loosen and fragmented sliding stratum, unfavorable soft structural plane, and external causes, including rain water infihration and tunnel slope excavation. For the analysis of stability of overlapping part of the front and side landslides, it shall be carried out by selecting the calculating values of deep and shallow sliding planes, whichever is smaller （i. e. most unfavorable result of stability）. Based on the calculating result, measures, such as anti-sliding piles, breast board between special shaped piles, steel pipe piles and pipe roof, are adopted for comprehensive treatment, getting good effect.