Internal degradation of buried sewage pipe causes sinkhole in a main road

摘要

It was difficult to assess the condition of drains and pipes as they were underground. The only solution to stop the leakage was replacement of the damaged pipe. The degradation of the internal surface of the pipe was due to the acid produced by biological life-forms and hydrogen sulfide gas. Chemical analysis confirmed the presence of SRB bacteria. Soil washed out by the leakage of sewer from the pipe formed cavities which resulted in the collapse of the road layers. If concrete pipes encounter similar conditions as in this case study, road collapse problems can happen in other parts of the city as well.