摘要
开展拱坝基坑回填土石体与大坝作用机制研究,对确保水库初期蓄水和运行安全具有重要意义。基于小湾、白鹤滩和乌东德等特高拱坝的上游基坑回填设计、施工和监测成果,提出回填土石体与大坝作用机制模型;结合理论和仿真方法,从坝基渗流场分布、坝体接触面热交换状态与坝体-基础整体工作性态3个方面,揭示了特高拱坝基坑回填土石体与大坝的作用机制。分析表明:(1)回填补强基岩,延长坝基渗流路径,具有渗流折减效应,回填高度与回填体等效渗透系数是影响折减系数的主要因素;(2)回填土石体可增强坝面保温效应,有利于温控防裂;(3)回填可提高大坝抗震性能,改善坝-基整体工作性态。建议的特高拱坝坝前基坑回填设计原则及工作流程图,可供国内外同类工程设计、施工借鉴。
Mechanism study between earth-rock mixture in pit backfill and super-high arch dam is of great significance to save dam stability during the initial impoundment and operating period.Based on the backfill design,construction and site monitoring experience of super-high arch dams such as Xiaowan,Baihetan and Wudongde,a mechanism model of the backfill earth-rock mixture and dam was proposed.Combined with theoretical and the finite element simulation method,three aspects of the mechanism are discussed including dam foundation seepage field distribution,the heat exchange state of the dam upstream surface and the overall working behavior of the dam-foundation.The analysis results shows that:(1)Backfill shows a reduction effect on seepage behavior by reinforcing bedrock fissures and extending seepage paths,and its height,equivalent permeability coefficient are the main factors.(2)Backfill enhances insulation effect of the dam surface,favorable for dam cracking control.(3)Backfill improves seismic behavior,and ameliorates the dam stress state during the construction stage.The general design principle and work flow for backfill construction of a super high arch dam is proposed,which can be used for reference in similar engineering construction.
作者
林鹏
李明
彭浩洋
魏鹏程
周绍武
谭尧升
LIN Peng;LI Ming;PENG Haoyang;WEI Pengcheng;ZHOU Shaowu;TAN Yaosheng(Department of Hydraulic Engineering,Tsinghua University,Beijing 100084,China;Shanghai Investigation,Design and Research Institute Co.,Ltdy Shanghai 200335,China;China Three Gorges Projects Development Co.,Ltd,Chengdu,Sichuan 610041,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2019年第S02期3680-3689,共10页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(51979146)。
关键词
水利工程
特高拱坝
基坑回填
土石混合体
渗透折减
hydraulic engineering
super-high arch dam
pit backfill
earth-rock mixture
seepage reduction
