悬挂式防渗墙控制管涌发展的模型试验研究

Experimental researches on piping development control by means of suspended cut-off wall in double and three layer embankment

利用室内砂槽试验,对有无悬挂式防渗墙以及不同土层结构的3种堤基管涌破坏过程进行了模拟,研究了悬挂式防渗墙控制管涌发展的机理以及悬挂式防渗墙对管涌发展过程的影响。试验结果表明,在双层和三层堤基中设置悬挂式防渗墙,可以改变砂砾层内部渗透压力的分布和管涌破坏发展的路径,提高管涌破坏的水力梯度,降低管涌破坏的流量、出砂量和破坏范围。但是,含悬挂式防渗墙的双层堤基和三层堤基的管涌破坏形式不同,双层堤基中,防渗墙上游侧的管涌破坏在砂砾层内部发展,而在三层堤基中防渗墙上游侧的管涌破坏在砂层顶面发展。

Based on the laboratory test, the destruction process of with or no suspended cut - off wall and different soil structure of 3 kinds of embankment piping were simulated, studied the mechanism of suspended cut - off wall control piping development and the impact of suspended cut - off wall on the development process of piping. The test results show that, set of the suspended cut - off wall in doub- le layer and three layer embankment, the suspended cut - off wall can change the distribution of the osmotic pressure inside the gravel layer and the development path of piping failure, improve the bydraulic gradient of piping failure, can reduce the flux, the sand content and the extent of damage when the piping occurred. However, the piping failure forms of double and three layer embankment with the suspended cut - off wall are different, in double layer embankment, on the upstream side of the cut -off wall the piping failure was developed in the internal sand, but in three layer embankment, on the upstream side of the cut - off wall the piping failure was developed on the top surface of the sand layer.