砂被筑坝技术在长江汊道封堵工程中的应用

Application of dam building technology by sand quilt in branch blocking project of Yangtze River

抛投中小型土工织物充砂体一般用于修筑潜坝或填槽,在长江大型汊道封堵工程中的运用比较少见。大型汊道水流流速快、填筑工程量大,使坝体成型控制难度大、施工效率低,应在工程中不断优化和改进施工设计及工艺。通过加大土工织物袋体尺寸,采用边充砂边沉放的方法连续施工,形成了成熟的砂被筑坝技术。实践证明,该技术的施工机械化程度高、程序简单、施工高效、坝体成型易于控制,且运用该施工技术修筑而成的汊道封堵坝能起到预期的工程效果。

Dumping mid- small geotextile sand- body is commonly used for submerged dike construction or gully filling,but it is rarely used in large branch blocking projects of Yangtze River. The control of dam forming in large river branches is difficult and the construction efficiency is low due to fast flow and large construction quantity,so the construction design and technique should be optimized and improved during the construction. Through increasing the size of geotextile sand- body,simultaneously filling and dumping,the matured technique of dam building by sand quilt is developed. The practice showed that the technique is highly mechanized,simple in procedure,efficient in construction and easy in the control of dam- body shape. The branch blocking dam constructed by the above technique is effective as expected.