The rock slope in the bridge and tunnel of a railway engineering, is generally characterized by great height and great slope angle. It is the key project to determine the feasibility of the whole railway line. For convenience,the slope is usually analysed and designed with the two dimensional plan. Therefore, there are often some mistakes in the engineering applications. In order to improve the situation, the rock slope in the bridge and tunnel for constructing the Lancangjiang bridge on the Dali-Ruili railway in Yunnan is taken as the temple in this study. And, a practical methodology for stability evaluation and engineering support measure for such rock slope is put forward. Firstly, based on the research of the site area rocks mass structure and the establishment of the geological model, the stability of the rock slope in a bridge and tunnel engineering is evaluated by the methods of three dimensional numerical simulation and strength reduction. Then, in order to deal with two engineering geological problems, that,(l) the overall instability controlled by particular combination of weak discontinuities; (2) instability of cataclastic rock masses in surface layer of the rock slope, different support measures are employed to solve different problems. A general rule is taken in all designs for slope support works, "ensuring overall stability, controlling local distortion and paying attention to the potential instable zone". More importantly, the construction of a bridge and excavation of a tunnel are all taken into account. To ensure security of the construction and the stability for slope support, the three dimensional numerical model of the bridge and tunnel are introduced to the engineering geological model. The practice in the slopes at Lancangjiang bridge in Dali-Ruili railway shows that the proposed method can effectively evaluate the slope stability and determine the support measures.%依托大理—瑞丽铁路澜沧江大桥桥隧工程边坡,通过大量的工程支护处理措施研究,探讨桥遂工程边坡稳定性分析及工程支护处理方法.在查明坡体结构、建立坡体地质模型的基础上,利用三维数值模拟和强度折减法对桥遂边坡进行稳定性分析评价,同时考虑桥梁结构建设和两岸遂道开挖施工对坡体稳定性的影响.对岩质边坡存在的受软弱结构面控制的整体稳定性问题和浅表层局部碎裂岩体的稳定性问题,分别采用不同的支护措施.岩质边坡稳定性分析应以建立工程地质模型为基础,边坡支护设计应与工程结构建设相结合,信息互馈,动态设计,以确保工程边坡的稳定性.
展开▼
