鲁地拉水库涛源金沙江大桥段库岸稳定性评价

Reservoir Bank Stability Evaluation on Taoyuanjinshajiang Bridge Segment of Ludila Reservoir

以鲁地拉水库涛源金沙江桥段库岸稳定问题为研究对象,基于历史库岸调查,结合两段法塌岸宽度预测经验公式与再造库岸边坡稳定性极限平衡法计算,综合评价库岸稳定性,所得主要结论如下:(1)涛源金沙江大桥大理岸历经多期内外动力地质作用,当前及未来一段时期趋于稳定。(2)涛源金沙江大桥大理岸塌岸预测宽度40~89 m,当前库岸到结构最小距离150 m,不会威胁到桥梁建构筑物。(3)涛源金沙江大桥永胜岸不存在库岸问题。(4)两岸自然边坡和再造库岸边坡在自然、降雨和地震工况下均满足工程稳定性要求。同时需要注意水稳定性较差砂层的切穿暴露;管理好工程弃渣,避免大规模改变现状库岸。

The Ludila Reservoir bank stability of Taoyuanjinshajiang Bridge segment is studied in this paper. It is comprehensively evaluated by historical exploration, bank slump width predicted by two-segment method and bank slump changed slope estimated by limit equilibrium method. The following main conclusions are drawn. Dali side of the bridge under multiple stages deformation is done by the inner and outside dynamic geologic processes, whose current and future stability tends to be stable. Bank slope fail maximum width being 89 m is less than the minimum distance of shore and structure being 150 m. So the bank slump does no harm to bridge and its affiliated structures. The Yongsheng side of the bridge has no bank slump problems. Both sides of the bridge under natural, rainfall and seismic working conditions all meet the requirements of engineering stability. Simultaneously, the sand stratum whose water stability is bad is strictly prohibited, the spoil disposal should be managed. Large-scale change for the reservoir bank is abandoned.