| 摘要: |
| 【目的】研究混凝土面板砂砾石坝防渗墙的应力变形及实际防渗效果，为高寒地区深厚覆盖层类似工程的设计与施工提供依据。【方法】以青海省纳子峡混凝土面板砂砾石坝为研究对象，在防渗墙施工及运行初期（2012-05-2018-01）对其进行应力监测、变形监测、渗流监测，对所得监测数据进行统计分析，进而评价防渗墙的实际工作状态。【结果】纳子峡混凝土面板砂砾石坝防渗墙各测点应力及变形表现稳定，在施工期防渗墙钢筋的应力变化因受地面施工等因素影响主要承受拉应力，且向上游侧倾斜；在水库运行期间（2014-09-2018-01），墙体受到来自上游的水压力，主要承受压应力，且向下游侧倾斜；布置在墙体上游侧的渗压计渗透压力远大于下游侧各测点，表明防渗墙防渗效果良好，渗透压力受测孔孔内水位影响，且随库水位表现出一定的周期性变化规律，库水位每抬升（或下降）1 m，墙体下游侧各测点渗透压力增加（或减小）约0.6 kPa。【结论】纳子峡大坝混凝土防渗墙在其施工及运行初期应力变形较为稳定，防渗效果良好，能为大坝的安全提供保障。 |
| 关键词: 混凝土面板砂砾石坝 防渗墙 应力变形监测 渗流监测 |
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| 基金项目:国家自然科学基金项目（51679197） |
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| Service performance of impervious wall on deep overburden foundation |
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LI Ming,QIN Yuan,XU Chengyong,et al
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| Abstract: |
| 【Objective】The stress and deformation of impervious wall of concrete face sand-gravel dam and its actual impervious effect were studied to provide basis for design and construction in similar fields of deep overburden in cold areas with high altitude.【Method】The Nazixia concrete face sand-gravel dam in Qinghai was selected,and the stress,deformation and seepage were monitored during the construction and initial operation stage (2012-05-2018-01) of the impervious wall.Then statistical analysis of the obtained monitoring data was conducted to evaluate actual working condition.【Result】The stress and deformation of the impervious wall of Nazixia face sand-gravel dam were stable.The stress change of steel bar of the impervious wall during the construction stage was mainly from tensile stress due to the influence of ground construction and other factors,and the impervious wall inclined to the upstream side.During the operation of the reservoir (2014-09-2018-01),the impervious wall was subjected to water pressure from the upstream mainly under compressive stress and inclined to downstream side.The osmotic pressure of the osmometer arranged on upstream side of the impervious wall was much larger than that of downstream side,indicating that the impervious effect of wall was good.The osmotic pressure was affected by water level in the measured hole with periodic variation.One meter change of water level resulted in 0.6 kPa change in osmotic pressure of each measuring point in downstream side.【Conclusion】The stress and deformation of the impervious wall of Nazixia concrete face sand-gravel dam were stable during construction period and initial stage of operation,and the seepage prevention effect was good, guaranteeing the safety of dam. |
| Key words: concrete face sand gravel dam impervious wall stress and deformation monitoring seepage monitoring |
