大瑞铁路怒江特大桥桥址方案地质比选研究

Study on Geological Comparison of Site Schemes for Nujiang Grand Bridge on Dali-Ruili Railway

拟建怒江特大桥为大理至瑞丽铁路全线重大控制性工程之一,桥址地处保山地块与腾冲地块碰撞缝合带—怒江断裂带内,怒江两岸深大断裂及褶皱发育,构造极其复杂,不良地质发育,特大桥受复杂地质环境及前后引线工程地质选线制约,选址困难。在前期工作确定的三个比选桥址基础上,通过分析研究三桥址工程地质条件,结合前后引线工程地质条件,综合定性分析和专家评判法结果,比选推荐了大坪子桥址方案。

The Nujiang Brand Bridge to be built is one of the key control projects on Dali-Ruili Railway. It locates within Nujiang Fault Zone, the collision suture zone of Baoshan Block and Tengchong Block, and the deep and large faults and folds are developed along the both banks with complex structures and unfavorable geology. Therefore the influence of such complicated geological environment and constraint of geological route selection of front and rear lead engineering result in difficult site selection. Based on three bridge site schemes for comparison confirmed by previous work, the engineering geological conditions of these three sites is analyzed and studied; combined with the geological conditions in the front and rear lead engineering and incorporated the qualitative analysis and experts＇evaluation, Dapingzi site scheme is recommended.