Friction and leakage characteristics of confined, reduced-scale inflatable structures

Abstract

This work is focused on the evaluation of the performance of a small-scale inflatable, or plug, placed in a confined space provided by a circular rigid pipe as a way to contain the propagation of floods. The rigid pipe is a simplified and scaled approximation of an actual tunnel section. The evaluations were conducted using an inflatable plug made of a single layer of coated Vectran® fabric. Friction coefficients of the system were calculated for three different materials lining the pipe so a comparison could be made. These friction coefficients were also compared to laboratory friction machine testing of the same lining materials. This comparison showed that the friction coefficients of the pipe-plug system were lower than the laboratory friction machine tests. Rates of water leakage around the plug were also studied. The leakage rates were recorded for several different plug pressures while varying the tunnel pressure accordingly. It was observed that as pressure differential decreased between the plug and pipe, the leakage rate increased. Results showed also that the plug was able to withstand a pressure differential with manageable water leakage rates.