金沙江特大桥桥址右岸岸坡工程地质问题研究

金沙江特大桥是丽（丽江）香（香格里拉）铁路的关键控制性工程之一，其桥基置于金沙江陡峻的峡谷岸坡上，岸坡是否稳定直接关系到桥址方案的可行性。从地形地貌、地层岩性、地质构造等方面对桥址方案右侧岸坡工程地质条件进行了分析，采用Sarma法、数值模拟方法，研究了桥基岸坡在自然状态、桥基开挖加载作用下、地震、水库设计蓄水等工况下的稳定性。研究结果表明:在考虑地震和水库设计蓄水影响下，岸坡将处于失稳状态，若作特大桥桥址必须对不良地质进行深入勘探，并进行切实可靠的工程治理。

Study on Engineering Geological Issues of Right Bank Slope at the Site of Jinshajiang Grand Bridge

Jinshajiang Grand Bridge is one of the major projects along Lijiang-Shangri-La Railway. The bridge foundation is located on the bank slope of Jinshajiang River＇s steep valley so that the stability of the slope relates directly to the feasibility of the bridge site scheme. From the aspects of landform, formation lithology, geological structure, the engineering geological conditions of the right bank slope in the scheme are analyzed and the stability of the bank slope for the bridge foundation in different cases, such as natural status, action of foundation excavation loading, earthquake, design water storage in reservoir, is studied by Sarma method and numerical simulation. The result shows that given the consideration of earthquake and design water storage in reservoir, the bank slope would be instable, if used as grand bridge site, it would have to be prospected deeply for unfavorable geology and conduct feasible and reliable engineering treatment.