基于PFC^(2D)楔形支挡不透水充灌袋挡水的研究

Numerical Analysis on Lateral Stability of Wedged Geomembrane Tubes

土工膜充灌袋广泛用于抗洪抢险、农业灌溉、河流改道、近海施工等临时性的堤坝建设中,当其承受过大侧向水压力时,充灌袋会发生滚动而失稳,在土工膜充灌袋一侧安装楔形体支挡结构是一种简单有效的防止翻滚的方法。本文基于PFC^(2D)程序对一侧安装楔形体支档结构另一侧作用一定高度水位的充灌袋挡水结构进行计算,对侧向水压力下充灌袋的整体稳定性进行了分析。为使研究具有普遍性意义,对充灌压力、支挡结构高度以及侧向水位高度都进行了无量纲化处理,计算了不同充灌压力、挡体高度下充灌袋的临界挡水高度,通过计算得出了临界挡水高度随充灌压力和挡体高度之间的关系。同时对充灌袋与支挡结构的相互作用产生的应力集中现象进行了计算分析,提出了解决应力集中的措施。研究成果为充灌袋挡水结构和支档结构的设计提供依据。

Prestressed Concrete Cylinder Pipe（ PCCP） is widely applied in underground conveyance engineering at home and abroad. PCCP is also used in the auxiliary projects of South-to-North Water Transfers in Tianjin. The compacting quality of backfill soil directly affects the engineering quality. So,how to detect compactness of deep backfill soil rapidly and accurately is very important to ensure the quality of the project. This paper puts forward compactness measurement method for deep backfill soil based on dynamic penetration and non-nuclear densimeter. Through field test,blow count of light dynamic penetration and compactness can be acquired for establishing correlation,which can be calibrated through field testing of compactness using non-nuclear densimeter. Through application in real project,compactness of deep backfill soil in PCCP construction has good correlation with blow count of light dynamic penetration. The method has the advantages of simple device,easy operation,economical and applicable. The precision can be improved through checking the relation curve along with engineering inspection. So the method is worth popularizing as a compactness measurement method for deep backfill soil of PCCP construction.