Pipeline Burst–Related Soil Stability in Collapse Condition

Abstract

Underground water main leakage is one of the main causes of instability of soils and sinkholes. In the event of a water main burst, the pressure is upward and hence the soil layer should be analyzed for blowout stability. Conversely, leakage from low-pressure utilities such as sewer pipes would erode the surrounding soil media and leave it unstable with an internal opening created. In such a situation, the possible failure scenario would be in collapse stability. This study set out to quantify the collapse stability performance of three idealized cavity shapes above the damaged pipe. Advanced numerical limit analysis was used to obtain upper and lower bound solutions of the problem. The study provides useful engineering information in the form of design charts and tables for a wide range of design parameters, which can greatly assist in decision making by practical engineers.