Suffosion Holes as the Results of a Breakage of a Buried Water Pipe

The result of a breakage of a buried water pipe is the watermovement in soil, which can cause that fine soil particles arewashed out from the solid matrix and transported through pores(suffosion process). It is widely known that the most hazardoussuffosion effects in urban areas relate to water-engineeringstructures. Holes, that can form on the soil surface by wateroutflowing after a failure of a buried pipeline (suffosion holes),are in different shapes and sizes. Recognition of factors influencingholes shapes and sizes would facilitate the preventionof hazardous suffosion effects connected with failures of waterdistribution systems. In the range of the presented article, theinfluence of selected parameters on the dimensions of suffosionholes was analyzed. The basis of the analysis was results oflaboratory investigations of the controlled leakage from a buriedwater pipe. The vast majority of values of suffosion holesareas, selected according to area of leak and hydraulic pressurehead in a pipe, occurred normally distributed. The tendencyof average area of suffosion holes to be higher with risingpressure head in a pipe was clearly visible, but we were asyet unable to select one regression model fitting measured andcalculated data better than others. Moreover, no tendency wasobserved between the biggest probable area of suffosion holeand pressure head in a pipe.