| 摘要: |
| 平原河网地区地下水与河道联系紧密,在地质条件较差或有隔污等要求时建库,常采用全库盆土工膜防渗方案,为了满足土工膜抗浮稳定及防止气胀等问题,通过膜下布设排水管网进行排水减压。本文依托某引调水工程全库盆土工膜防渗平原水库,采用多孔介质渗流和管道流耦合的地下水流模拟方法,模拟复杂排水管网和库区岩土体共同作用的复合渗流场,结果显示该方法可较好地反映出膜下复杂排水管网的排水减压效果。通过对比不同排水方案、土层渗透性能等条件下的渗透压力分布,结果表明,正交管网闭合小区内膜下渗透压力从小区中心向四周排水管逐渐降低,闭合小区内减压效果明显,坝脚位置膜下渗透压力明显高于库内区域,需要增设坝脚排水管。淤泥质粉细砂层渗透性对膜下渗透压力影响较大,水库低水位运行期间应加强对膜下渗透压力的监测。研究成果可为平原河网地区全库盆土工膜防渗水库工程的渗控设计和安全运行提供参考。 |
| 关键词: 平原水库 土工膜 全库盆防渗 渗透压力 排水减压 |
| DOI： |
| 分类号:TV44 |
| 基金项目:水利部堤防安全与病害防治工程技术研究中心开放课题基金资助项目(LSDP202203)；中央级公益性科研院所基本科研业务费(Y122001)；贵州省科技计划项目(黔科合支撑[2020]4Y024) |
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| Analysis of drainage and depressurization under geomembrane of the whole reservoir basin in plain river network region |
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LU Bin1, TAN Haijin2, ZHANG Baosen3, HE Miaomiao4, ZHANG Yu5, XIE Xinghua5
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1.Research Center on Levee Safety and Disaster Prevention,Ministry of Water Resources;2.Guangdong Hydropower Planning and Design Institute;3.Research Center on Levee Safety Disaster Prevention,Ministry of Water Resources;4.Water Conservancy Bureau of Wuzhong District;5.Nanjing Hydraulic Research Institute
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| Abstract: |
| In the plain river network area, groundwater interacts closely with the river. When a reservoir is built on poor geological conditions or there are requirements for separate soil pollutants, the whole reservoir basin needs anti-seepage use geomembrane. In order to solve the problems of anti floating stability and prevent air bulge of geomembrane, drainage pipe network is buried under the geomembrane for drainage and depressurization. This paper research on a plain reservoir of a water diversion project, the whole reservoir basin is laid geomembrane to anti-seepage. The groundwater flow simulation uses the method of coupling porous media seepage and pipe flow, and the complex seepage field formed by complex drainage network and groundwater was simulated, the simulation results shown that this method can reflect the drainage and depressurization effect of the complex drainage pipes under the geomembrane. By comparing the seepage pressure distribution under different drainage pipes layout and sand layer permeability cases, the results shown that the seepage pressure under the geomembrane gradually decreased from the center to the surrounding pipes in the pipes closed area of orthogonal pipe network, and the depressurization effect was obvious in the closed area. The seepage pressure at the dam toe is significantly higher than that in the reservoir area, so it is necessary to add drainage pipes at the dam toe. The permeability of muddy silty fine sand layer has a great influence on the seepage pressure, so it is very important to monitor the seepage pressure during the low water level conditions of the reservoir. The research results can provide reference for the seepage control design and dam safety of reservoirs with geomembrane in the whole reservoir basin in plain river network areas. |
| Key words: plain reservoir geomembrane anti-seepage in the whole reservoir basin seepage pressure drainage and depressurization |
