为研究向家坝坝基排水孔组合式过滤体结构形式及主要材料性能指标,向家坝电站拟采用组合式过滤体对通过坝基地质缺陷层的排水孔进行反滤保护。根据地质缺陷层的渗透变形试验以及过滤体的主要材料如土工织物、泡沫塑料等的室内试验成果,并结合工程经验,研究确定了组合式过滤体的结构形式及主要材料性能指标。组合式过滤体的反滤试验及长期淤堵试验成果表明,组合式过滤体可以对坝基地质缺陷层进行有效的反滤保护,并在长期运行期间具有较好的抗淤堵能力。

In order to study the structure and performance indexes of main materials of combined filter of drainage holes for dam foundation in Xiangjiaba project,we use combined filter to protect the drain holes which are drilled through the weak soil layers.On the basis of the results of permeability experiments of weak soils in dam foundation and indoor experimental results of the main materials such as geotextiles and foamed plastic,the structure of combined filter and main performance indexes of the materials are determined in association with engineering experiences.The filtering and silting experiments show that the combined filter is effective to protect the weak soil layers,with little silting in long-term operation.