阿尔塔什水利枢纽坝基深厚覆盖层防渗及坝体结构设计

Design of Dam Body Structure and Seepage Control for Deep Overlying Strata in Dam Foundation of Aertash Hydro Project

根据高地震区高坝对大坝安全的设计要求,并结合砂砾石—堆石混合料混凝土面板坝的特点,在坝体渗流控制、坝体变形控制、大坝抗震结构设计等方面,进行了系统的分析研究。针对砂砾石料修建混凝土面板堆石坝的特点,在坝体结构设计中提出从上游至下游渗透系数按照"垫层<过渡层<砂砾石主堆筑区<爆破堆石区"的要求,不设专门的排水体也可以确保坝体排水自由通畅;提出了利用天然砂砾料压缩模量高的特点合理提高坝料填筑标准,减少坝体沉陷量,可有效改善面板的应力变形状态;在高地震区、深覆盖层上修建高坝,为控制大坝和坝基变形、提高大坝抗震性能,对混凝土防渗墙结构及其施工程序的改进进行了探讨。

Based on the safety design requirements for the high dam in strong earthquake areas and combined with the characteristics of the concrete face rockfill dam with sandy gravel and rockfill materials ,the systematic analysis and study are carried out in the respects of dam’s seepage control ,deformation control and seismic structure design ,and the ar-rangement requirement of permeability coefficients is proposed according to “cushion layer ＆lt; transtion layer ＆lt; sandy gravel area ＆lt; blast area” from the upstream to downstream in dam structure design ;Simultaneously ,it is proposed that rationally raising the filling criterion of dam materials and reducing the dam settlement could effectively improve the stress deforma -tion of face slab ;Finally ,the improvements for impervious wall structure and its construction procedure are discussed when building the high dam in strong earthquake areas and on deep overlying strata in order to control the dam deforma-tion and raise the dam earthquake resistance .