聚乙烯微孔波纹管排水系统在播山沟水坠坝施工中的应用研究

Application of Corrugated Polyethylene Pipe Drainage System in Construction of Bowagou Hydraulic Fill Dam

水坠筑坝施工期坝体排水常采用沙井、沙沟等设施。在沙石料缺乏的甘肃省定西县播山沟水坠坝施工中，采用聚乙烯微孔波纹管网进行坝体排水，取得良好的效果。播山沟坝坝高２３．５ｍ，其中冲填坝高１６．５ｍ，间歇冲填施工，布设聚乙烯微孔波纹管网３层．纵横交叉贯通，管外缠绕塑料编织布滤水，铅丝绑扎接头，在停冲期埋设水平管网。实测施工期波纹管排水量３３２８．６７ｍ３，占计算应排水量的８３．３％；最大日排水量为３６．２８ｍ３，日排水量与冲填泥浆浓度及停冲后的天数密切相关。该坝施工期未发生坝坡鼓肚、滑坡等问题。

In construction period,sand wells and sand gullies were usually used as drainage installations in the dam body of hydraulic fill dam.In the construction of Bowagou hydraulic fill dam in Dingxi County of Gansu Province,for lack of sand and stone materials,it had gained better effect to drain water through corrugated polyethylene pipe net.Bowagou dam was 23. 5 meters high with 16. 5 meters of fill height by intermittent fill.It was arranged with three layers of crisscross corrugated polythlene pipe net, the pipes were wrapped with plastic weaver to filter water,the joints were tied with lead wire.The level pipes Were covered up in fill-stop period.The drainage amount of corrugated pipes observed on-the-spot was 3328.67 m3 in construction period,occupying 83.3% of the calculated drainage amount 3 the maxium drainage amount per day was 36.28 m3,which had close relation with fill muddy density and days after fill-stop.The problems such as bulge and land slide did not take place in construction period of the dam.