Testing device and method for measuring permeability coefficient and permeability path of soil-structure interface

The invention relates to a test device for measuring a soil-structure interface permeability coefficient and a permeability path. The test device comprises a triaxial system, a pressure loading system, a soil particle collection system and a data acquisition system, the triaxial system comprises a pressure chamber; the pressure loading system comprises an input water head panel, an output water head panel and a confining pressure control panel; the soil particle collecting system comprises a conical drain pipe, a soil particle collector, a precision balance and a turbidimeter; the data acquisition system is respectively connected with the input water head panel, the output water head panel, the confining pressure control panel, the turbidimeter and the precision balance; the pressure chamber is connected with the confining pressure control panel; the top cap is connected with the input water head panel; the soil particle collector is connected with the output water head panel; and the conical drainage pipe is