Strainer Structure of Porous Underdrain Pipes Taking Account of Clogging by Soil Suspension Flow

Abstract

Underdrain pipe is one of effective slope protection works that can be adopted practically. As fine soil particles are suspended in percolating water, a strainer structure of underdrain pipes is necessary to prevent clogging by soil suspension flow. This study deals with effective forms of strainer structure of underdrain pipes for slope protection. Experimental results showed that the underdrain pipe discharge through the funneledstrainers was larger than that through the constant pore radius strainers. Also, the ratio of underdrain pipe discharge through the funneled strainers to that through the constant radius strainers increased with the increase in volume concentration of percolating suspension. Additionally, it was analysed on the basis of rheological properties of soil suspension flow which prevents clogging that the effective strainer structure of underdrain pipes is the funneled strainer in which pore radius is larger in the flow direction.
According to experimental and theoretical results, it was concluded that a strainer with enlarged pore radius toward flow direction is more effective than a strainer with constant pore radius.