摘要
随着土工膜广泛应用于水库大坝防渗,土工膜缺陷引起的大坝渗漏问题严重威胁着水库大坝安全和工程效益发挥。针对某土工膜防渗调蓄水库主坝渗漏问题,建立有限元计算模型,计算了土工膜缺陷位置、尺寸对主坝浸润线、渗流场位势等渗流特性的影响,分析了渗漏成因,并结合高密度电法、安全监测资料、补充地勘资料进行验证。结果表明,渗漏原因为主坝坝体填土压实度较低、部分具有湿陷性导致主坝沉降量大引起坝坡土工膜受拉破坏;随着土工膜缺陷位置上移,浸润线高程先增大后减小,且局部有凸起现象;膜后消杀水头随土工膜缺陷尺寸增大而缓慢减小,随缺陷位置上移先基本不变后显著增大;桩号0+070断面上游坝坡与库底交界处上方附近、桩号0+270断面上游马道附近土工膜发生破损。研究结果可为同类工程病险诊断、设计和运行管理提供参考。
As geomembrane is widely used in reservoir dam seepage prevention,dam leakages caused by geomembrane defects seriously threaten the safety of reservoirs and engineering benefits.Aiming at the problem of the main dam of a geomembrane anti-seepage regulation reservoir,this paper established a finite element model to calculate the impact of the location and size of geomembrane defects on the main dam's infiltration line,seepage field potential,and other seepage characteristics,and the causes of leakage were analyzed.The causes were verified by combining high density electrical methods,safety monitoring data,and supplementary geological surveys.The results show that the reason for the leakage is that the compactness of the filling soil in the main body is low and partially collapsible,which leads to the large settlement of the main dam and the damage of the geomembrane caused by tension.As the defect position of the geomembrane moves upward,the elevation of the infiltration line presents a trend of first increasing and then decreasing,and there are local protrusions.The post-membrane disinfecting water head decreases slowly with the increase of the defect size of the geomembrane,and with the defect position moving up,it is basically unchanged at first and then increases significantly.The geomembrane was damaged near the junction of the upstream dam slope and the bottom of the reservoir at the section of stake No.0+070,and near the upstream horseway of the section of stake No.0+270.The research results can provide reference for risk diagnosis,design and operation management in similar projects.
作者
刘欣怡
李卓
蒋景东
姜鑫
方艺翔
LIU Xin-yi;LI Zhuo;JIANG Jing-dong;JIANG Xin;FANG Yi-xiang(Institute of Dam Safety and Management,Nanjing Hydraulic Research Institute,Nanjing 210029,China;Dam Safety Management Center of the Ministry of Water Resources,Nanjing 210029,China;College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China)
出处
《水电能源科学》
北大核心
2024年第2期134-137,201,共5页
Water Resources and Power
基金
国家自然科学基金项目(51979173)。
关键词
水库大坝
土工膜缺陷
渗漏
数值模拟
高密度电法
storage reservoir
geomembrane defects
leakage
numerical simulation
high density electrical method
