小型土石坝下游坡墙式结构稳定性分析  

A Structural Stability Analysis of the Downstream Slope Wall of the Small Earth-rock Dam

作　　者：田林钢 陈晓宇 张宪雷 李扶政 TIAN Lin-gang;CHEN Xiao-yu;ZHANG Xian-lei;LI Fu-zheng(North China University of Water Resources and Electric Power,Zhengzhou 450046,Henan Province,China)

机构地区：[1]华北水利水电大学水利学院,河南郑州450046

出　　处：《中国农村水利水电》2023年第1期194-199,共6页China Rural Water and Hydropower

基　　金：国家自然科学基金(52009045);河南省科技攻关项目(212102310539)。

摘　　要：针对下游坡墙组合结构小型土石坝安全稳定问题,现行规范理论将挡土墙视为坝体结构的一部分评价结构稳定性,具有一定的局限性,且由于获取相对刚性的干砌石挡墙抗剪强度指标难度较大,工程上常选用经验值。为准确评价组合结构的稳定,厘清坡墙组合结构失稳的主要影响因素,视坝体和干砌石挡墙为独立结构,采用Geo-Studio有限元软件首先选用Morgenstern-Price法分析了正常运行工况下游坝坡稳定性,然后依据孔隙水压力分布和坝体与挡土墙接触面处x向应力与高程分布曲线,得到接触面上作用荷载进而计算得到了抗滑和抗倾覆稳定安全系数,综合坝坡和挡土墙稳定分析成果,明确了导致坡墙整体结构失稳的主要原因。分析成果表明挡土墙与坝体高度比、下游坝坡坡比是影响组合结构稳定的主要因素,提出了运用边坡和挡土墙稳定系数曲线交汇法评定最优设计参数。Aiming at the safety and stability of small earth-rock dams with downstream slope-wall composite structure, the current code theory regards the retaining wall as a part of the dam structure to evaluate the structural stability, which has certain limitations. The shear strength index is difficult, and the empirical value is often used in engineering. In order to accurately evaluate the stability of the composite structure and clarify the main influencing factors of the instability of the combined structure of the slope and wall, this paper regards the dam body and the dry stone retaining wall as independent structures, and uses the Geo-Studio finite element software to first use the MorgensternPrice method to analyze the normal. The stability of the downstream dam slope under operating conditions, and then based on the distribution of pore water pressure and the x-direction stress and elevation distribution curve at the contact surface between the dam body and the retaining wall, the acting load on the contact surface is obtained, and the anti-sliding and anti-overturning stability and safety are calculated. The analysis results show that the ratio of the height of the retaining wall to the dam body and the slope ratio of the downstream dam slope are the main factors affecting the stability of the composite structure.

关 键 词：稳定性分析 小型土石坝 坡墙组合结构 渗流场-应力场耦合 计算分析 

分 类 号：TV314[水利工程—水工结构工程]