刁海鹏 侍克斌 白现军 董正宇

摘 要：为研究围堰在降雨及水位变动下的渗流特性及边坡稳定情况，以阿扎德帕坦水电站下游土石围堰为例，对比两种不同围堰剖面设计方案，考虑短历时强降雨工况，基于非饱和渗流原理，对两种围堰断面方案在渗流应力耦合状态下遭遇水位变动和短历时强降雨时的渗流和边坡稳定性情况进行了有限元模拟。方案1结构较为简单，围堰上游边坡（背水坡）为1∶1.50，下游边坡（迎水坡）为1∶1.75，迎水坡采用厚0.5 m的块石护坡，围堰堰身和下部基础采用高喷防渗墙。方案2结构较复杂，相比于方案1，防渗墙前移，围堰顶部采用厚40 cm、C20W6F100的混凝土板，防止在过流时对其造成严重冲刷。结果表明：方案2上下游边坡防渗效果均比方案1更具针对性，且围堰渗流特性及阻渗效果较好;在不同静水位条件下，方案2上下游边坡的安全系数整体上大于方案1的，且满足规范要求，其整体稳定性优于方案1的;水位变动时，无论是水位上升还是下降，降雨对围堰上游边坡的安全系数基本没有影响，但降雨会降低下游边坡的安全系数，降雨强度越大，安全系数就越小。

关键词：土石围堰;渗流特性;稳定分析;断面优选;降雨

中图分类号：TV551.3 文献标志码：A

doi：10.3969/j.issn.1000-1379.2021.07.025

引用格式：刁海鹏，侍克斌，白现军，等.考虑渗流应力耦合效应土石围堰断面方案研究[J].人民黄河，2021，43（7）：130-136.

Abstract： For studying the cofferdam under rainfall and water level changes of seepage characteristics and the slope stability， taking earth-rock cofferdam downstream of Azad PatanHydroelectric Power Station as an example， it compared two different cofferdam section designs and considered the actual conditions in dry season and flood season on the basic of principle of unsaturated seepage flow in two kinds of cofferdam seepage flow stress coupling conditions confronted with water level fluctuation and rainfall seepage and slope stability conditions for finite element simulation. The results show that a） the anti-seepage effect of the upstream and downstream slopes of the scheme 2 is more targeted than that of the scheme 1 and the seepage characteristics and seepage prevention effect of the cofferdam are better; b） under different static water levels， the overall safety factor of the upstream and downstream slopes of the scheme 2 is greater than that of the scheme 1 and meets the requirements of the specification; c） when the water level fluctuates， whether it is rising or falling， rainfall has basically no effect on the safety factor of the upstream slope of the cofferdam， while rainfall will reduce the safety factor of the downstream slope， the greater the rainfall intensity， the smaller the safety factor.

Key words： earth and stone cofferdam; seepage characteristic; stability analysis; optimum selection of section; rainfall

1 引 言

水利水电工程中施工导流围堰一般可分为土石围堰和混凝土（浆砌石）围堰，其中土石围堰作为施工导流时的一种临时性挡水建筑物，通过临时性拦挡河水为永久建筑物的施工创造干地条件，在工程设计和施工中其渗流及邊坡稳定问题一直受到重点关注[1-2]。……