打入型土工筒袋在河道塌坡生态治理中的应用

The application of driven geotextile canister bags in ecological treatment of river slope collapse

通过将打入型土工筒袋与直立式预制桩组合技术在河道塌坡中应用,能有效解决预制桩等直立式挡墙护岸结构在不能采取大开挖情况下挡土和滤水等方面存在的瓶颈问题。以八一大沟河道塌坡工程为例,通过现场查勘及钻探工作,查明了塌坡段规模及土性,分析了塌坡成因,并结合河道不能断流施工、临河道路不能中断交通等因素,经经济技术比选选用坡顶灌注桩、坡脚管桩联合支护方案。在坡脚水位变化区采用不连续布置管桩+桩后土工筒袋措施,成功解决了传统做法不易实施的问题,达到了桩间防漏土以及桩前后水体交换的目的,从而降低了云龙湖大坝坝后渗水出逸点高度,且该治理方案造价相对较低并具有生态治理效果。

The application of the combination technology of driven geotextile bags and vertical prefabricated piles in river slope collapse can effectively solve the bottleneck problems of vertical retaining walls and bank protection structures such as prefabricated piles in retaining soil and filtering water when large excavation cannot be carried out.Taking the collapse project of the Bayi Dagou River as an example,through on-site investigation and drilling work,the scale and soil properties of the collapse section were identified,the causes of the collapse were analyzed,and combined with factors such as the inability to cut off the flow of the river and the inability to interrupt traffic on the riverside road,a combined support scheme of top grouting piles and foot pipe piles was selected through economic and technical comparison.The discontinuous arrangement of pipe piles and geotextile bags behind piles in the water level change area at the foot of the slope has successfully solved the problem of difficult implementation in traditional methods,achieving the purpose of preventing soil leakage between piles and exchanging water before and after piles,thereby reducing the height of the seepage point behind the Yunlong Lake Dam.Moreover,this treatment plan has a relatively low cost and ecological governance effect.