纵向增强体土石坝内置心墙受力安全性分析  

Safety Analysis of the Earth-rock Fill Dam with Built-in Longitudinal Reinforced Wall

作　　者：梁军[1] 杨燕伟 LIANG Jun;YANG Yanwei(Water Resources Dept.of Sichuan Province,Chengdu 610016,China;China Changjiang Construction Investment Co.,Ltd.,Chengdu 610213,China)

机构地区：[1]四川省水利厅,四川成都610016 [2]中建长江建设投资有限公司,四川成都610213

出　　处：《工程科学与技术》2020年第5期110-116,共7页Advanced Engineering Sciences

基　　金：四川省重大水利科研项目(2016003)。

摘　　要：纵向增强体土石坝是基于“刚柔相济”建坝思路提出的一种新坝型,在土石坝中设置刚性防渗心墙与原土石坝体一起形成坝体结构。纵向增强体将坝体分为上游临水一侧和下游背水一侧,增强体同时受到上、下游两侧的水土压力作用,起到双向挡土墙的作用。随着上游库水位的变化,作用在增强体上的水土荷载也产生动态变化,从而引起增强体位移方向和大小变化,导致增强体上下游两侧堆石区存在主动力区与被动力区的转换。本文提出了纵向增强体受力安全系数的概念,应用库伦土压力理论分析增强体在竣工期、正常蓄水期和水位骤降3种典型工况下的受力状态,分别给出了3种典型工况下纵向增强体受力安全系数的表达式。在此基础上,从纵向增强体双向挡土墙不同于常规挡土墙单向受力的特点出发,根据增强体受力安全系数研究其与坝坡稳定性之间的关系,提出了临界坝坡时的被动土压力计算方法。研究表明:作为双向挡土墙的增强体无论受力、变形还是自身稳定都与坝坡稳定性有关,纵向增强体蓄水期的被动土压力将随主动压力的增长而得到激发,受力程度也将得到更好地发挥,实现等强增效的力学特点;非临界坝坡设计中采用由本文临界坝坡时计算得到的被动土压力折减系数是偏于安全的,增强体土石坝断面可以进一步优化。The longitudinal reinforced earth-rock dam was a new type of dam.The dam structure was formed by setting the rigid impermeable core wall in earth-rock dam,that the rigid core-wall played an important role in anti-seepage water and soil pressure and resistance to deformation.The dam was divided into the upstream side and the downstream side by rigid core-wall,and the displacement of the wall and the water and soil load born by the wall changed with the water level on the upstream side.A transition between active and passive stress states was unlocked in the driven area of the upper and lower dam,which was segregated by rigid wall.Based on the Coulomb earth pressure theory and the safety definition of rigid core-wall bearing load that was proposed in this paper,the safety of rigid core-wall as the retaining wall bearing water and soil pressure was analyzed under three conditions of completion,normal water storage and sudden drawdown of water level,and the analytic formulas of safety in the three conditions were provided.On this basis,according to the relation between the wall safety and the dam stability the calculation method of the reduced coefficient of passive earth pressure was proposed.This calculation method considered the role that the rigid core-wall bored bidirectional water and soil pressure front and behind dam.The result showed that the stress conditions deformation and stability of the wall and the dam stability interrelated.The passive earth pressure loaded in the wall was unlocked with the increase of active pressure under normal water storage condition,and the coefficient of passive earth pressure was bigger than the other two conditions.The coefficient of passive earth pressure obtained by the calculation method in this paper was on the safe side,and the sectional shape of dam could be further optimized.

关 键 词：纵向增强体心墙土石坝 坝体稳定性 心墙体受力安全系数 双向档土墙 被动土压力系数 坝体优化 

分 类 号：TV47[水利工程—水工结构工程]