Infiltration Experiments in Layered Structures of Upper Porous and Lower Fractured Media

Investigation of infiltration through unsaturated zone which consists of both porous and fractured media is important for comprehensively understanding water circulation and effectively man- aging groundwater resources and contamination control. Infiltration experiments for three kinds of porous-fractured layered structures were conducted with application of a rainfall simulator in this in- vestigation. During experiments, the volumetric water contents of porous media and on the interface of porous-fractured media were monitored by moisture sensors （TDT）. The infiltration rate, water amount in the profile and on the interface between the soil and the fractured bedrock, and outflow from the layered structures were analyzed to identify the effects of porous-fractured interface on water movement in the upper porous media and the effects of various kinds of porous media on infiltration in fractured rocks. It has been observed from the experiment results that the porous media and the frac- tured rock bear considerable reciprocal impact each other on infiltration processes and water content distribution. The results showed fractured rock prevented vertical water movement in the layered structure, and it decreases infiltration rate of layered structure and slows the process for upper porous media saturation.