基于变形协调的黏土心墙坝岸坡比优化方法  

Optimization method of bank slope ratios for clay core wall dams based on compatible deformation analysis

作　　者：李庆斌[1] 郭万里 皇甫泽华 武颖利[2] LI Qingbin;GUO Wanli;HUANGFU Zehua;WU Yingli(State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084;Geotechnical Engineering Department,Nanjing Hydraulic Research Institute,Nanjing 210024;Construction Management Bureau of Qianping Reservoir,Henan Province,Zhengzhou 450003)

机构地区：[1]清华大学水沙科学与水利水电工程国家重点实验室,北京100084 [2]南京水利科学研究院岩土工程研究所,南京210024 [3]河南省前坪水库建设管理局,郑州450003

出　　处：《水力发电学报》2021年第12期87-95,共9页Journal of Hydroelectric Engineering

基　　金：河南省水利科技攻关计划项目(GG201704)。

摘　　要：岸坡与坝体的变形协调问题是黏土心墙坝的重要工程问题,岸坡比则是变形协调的主要影响因素。为了从变形协调的角度对岸坡比进行优化设计,以前坪水库黏土心墙土石坝为例,基于有限元计算,分析了不同岸坡比对坝体变形协调性的影响,主要结论如下:(1)以坝体的最大沉降和变形梯度作为变形指标,以应力拱效应中的应力劣化度作为应力指标,以应力水平作为强度指标,这三类指标可以统称为坝体与岸坡的变形协调评价指标;(2)以岸坡稳定可靠性指标为安全控制指标,以削坡开挖土方量作为经济性控制指标,可以分别确定岸坡比的上、下边界,作为多目标优化分析的优化区间;(3)除变形协调评价指标外,同时引入安全指标,通过各指标功效函数之间的权重组合,对目标函数求极小值,可以实现对岸坡比的多目标优化设计。以所分析的黏土心墙坝为例,基于变形协调控制的优化坡角(坡比)为58°,能同时满足坝体与岸坡的安全性、经济性和变形协调性,表明所提出的岸坡比优化方法是合理的,能为设计提供科学依据。Compatible deformation between a dam body and its bank slopes is a crucial engineering issue of clay core dams, and the bank slope ratio is a major influencing factor of the deformation compatibility.To optimize the design of this factor, this paper examines the influence of different bank slope ratios on the compatible deformation, using finite element calculations in a case study of the Qianping clay core dam. We conclude that,(1) three indexes are crucial to analysis of the deformation, namely, compatible deformation evaluation indexes for a dam body and its bank slopes-a deformation index for the maximum settlement and deformation gradient of the dam body, a stress index for the degree of stress deterioration under the arch effect on dam stress, and a strength index for the stress level of the dam body;(2) If the stability and reliability index of bank slopes is used as a safety control index and the earthwork volume of slope cutting as an economic control index, we can determine separately the upper and lower limits of the bank slope ratio, which give an optimization interval for multi-objective optimization analysis;(3) In addition to the three indexes above, a safety control index is added to the evaluation system, so that we can realize a multi-objective optimization design of bank slope ratios, through combing the weights of the functions for all the indexes and minimizing the objective function. In the Qianping dam case,optimization based on the compatible deformation control gives an optimal slope ratio(slope angle) of 58°. This result meets all the three requirements of safety, economic efficiency, and dam-bank slope compatible deformation, thus indicating our bank slope ratio optimization method is effective and practical for dam design.

关 键 词：黏土心墙坝 变形协调 岸坡比 优化方法 多目标 

分 类 号：TV641[水利工程—水利水电工程]