金沙江中游上江坝址河床深厚覆盖层建高坝可行性探讨

摘 要 上江坝址为金沙江中游龙头水库的比选坝址之一，坝址河床覆盖层最厚达206.2 m，在深厚覆盖层上修建最低249 m级的高土石坝，大坝规模达到甚至超过世界前沿水平，筑坝技术难度大。通过测绘、钻探、物探、物理力学测试等工作揭示:(1)河床覆盖层由漂卵石、低液限粘土、砾卵石、碎块石、砂砾石等组成；(2)河床覆盖层中各粗粒土强度相对较高，低液限粘土强度较低，为坝基一条连续完整的相对软弱带；(3)坝址位于龙蟠断陷盆地内，主要受新构造垂直差异运动的影响，河床接受金沙江上游及坡体上物质堆积，逐渐形成了现今的深厚覆盖层。初步研究本坝址在河床覆盖层上建高土石坝是可行的，但需要对坝基采取工程处理措施。探讨了不同建坝方案所引发的工程地质问题，为筑坝技术研究提供了地质依据。

FEASIBILITY STUDY ON CONSTRUCTION OF HIGH DAM AT MIDDLE REACHES OF JINSHA RIVER WITH THICK RIVERBED DEPOSIT

Shangjiang is one of the sites for constructing the leading dam to the middle reaches of Jinsha River Reservoir dam site. The maximum thickness of Quaternary soil is 206.2 m in the river at the possible dam site. The minimum height of the embankment dam is 249 m. The size of the dam. Construction of such dam is of a great difficulty. Through mapping,drilling,physical exploration,the work of physical and mechanical testing have revealed:(1) the bed deposits composed of the drift gravel,low liquid limit clay,...