岸坡水平排水孔现场试验及地下水监测成果分析

为研究岸坡水平排水孔技术的排水效果，在长江中游航道江陵高滩守护工程中布置水平排水孔现场试验段。在布置盲沟等传统排水措施基础上，增设不同深度的采用可拆换式过滤体的水平排水孔，与仅采用传统排水措施的工程比较排水效果，检验水平排水技术的有效性与可操作性。监测成果表明，岸坡内水位与长江水位变化关系密切:在江水位上涨阶段，江水流向岸坡，与岸坡地下水形成补给关系;然而在江水位下降阶段，岸坡地下水流向长江，形成排泄关系。增加水平排水孔后，岸坡排水效果要优于仅采用常规盲沟试验段的排水效果，孔深为15 m方案的排水效果要优于孔深为8 m的排水效果。研究表明岸坡水平排水孔起到了较好的排水减压作用。

Horizontal Drainage Holes in Bank Slope:In-situ Test and Groundwater Monitoring

In the aim of investigating the drainage effect of horizontal drainage holes in bank slope,in-situ tests were carried out on a bank slope of Yangtze River through arranging horizontal drainage holes of different depths with re-placeable filter.The drainage effects were compared with that of blind ditch to validate the effectiveness and opera-bility of drainage holes.Results of water level monitoring suggest that the water level in bank slope is closely related with that of the Yangtze River:when river water level rises,groundwater of bank slope is recharged;whereas when river water level declines,groundwater of bank slope discharges to the river.We conclude that horizontal drainage holes have good effect in drainage and pressure reduction.The drainage effect of bank slope in the presence of drainage holes is better than that of conventional blind ditch;and the effect of drainage holes of 15m depth is supe-rior to that of 8m depth.