细沙河道上修建地下集水廊道的工程实践

Engineering practice of underground infiltration gallery in fine-sand river-bed

为弄清地下集水技术在含细沙河流上的适用性及面临的工程问题,以修建在某细沙河道上的两个地下集水廊道工程为例,从含水层颗粒级配入手,探讨滤层设计、出口渗流控制及运行管理等因素对地下集水廊道滤层工作性能的影响,分析了工程滤料失效的原因,提出了相应的改进措施。研究结果表明:在具有一定细沙含量的河道上修建地下集水工程是可行的;当前的滤层设计准则不符合地下集水廊道滤层的运行工况,应重新建立基于低水头、大流量、强透水工况下的滤层设计准则。

For exploring suitability and engineering problems encountered in construction of underground infiltration gallery in fine -sand river- bed, two engineering cases are analyzed and compared. Focusing on sand grain composition, we study three factors that influence the performance of underground infiltration gallery, namely filter layer design, seepage protection at outlet and project operation management, and the failure causes of the filter as well as corresponding solution are discussed. The research results indicate that it is feasible to build underground infiltration gallery on riverbed with moderate content of fine - sand ; the traditional filter layer design rule does not suit for the operation condition of underground infiltration structures, therefore new design rules that is based on low water- head, large discharge and strong permeability cases should be proposed.