Impact of Voids on Buried Utility Pipes Subjected to Surface Traffic Loading

The integrity and performance of buried pipe infrastructure is vital to our society for the provision of safe potable water and, transportation of sewage. For this purpose, a diverse range of buried utility pipes are deployed ranging from large diameter concrete sewer pipes to small diameter fresh water pipes, historically manufactured from cast iron and more recently plastic. Municipal water distribution and wastewater infrastructure systems are of national importance for any country and the aspect of water leakage; coupled with water scarcity, has become a serious problem in many countries around the world. For example, in the UK up to 22% of potable water can be lost from source to tap to leakage or failure of the pipe network (Laspidou, 2014). Currently we cannot predict when an individual pipe will reach the end of its serviceable life due to the complex, range of factors that contribute to their deterioration. For example, due to their shallow burial depth they are vulnerable to (i) the impact of increasing surface traffic load intensity, (ii) initial and temporal burial conditions and (iii) climate effects that contribute to increased variability of moisture content and temperature within the soil.
This project focuses on examining the impact of surface loading and burial conditions, specifically the role of void formation on plastic pipe behaviour. Small scale physical experiments using the University of Sheffield 4m diameter centrifuge have been undertaken to provide insight of the role of these factors in the pipe-soil interaction behaviour. The results have shown increased pipe bending moment and deflection were observed with the increase of void size confirming that void formation may contribute in the overall failure of pipe infrastructure. Moreover, a decrease in bending moment and pipe deflection were noticed with increase of internal water pressure of the pipe, burial depth and the presence of a road surface. Thesis also covers traffic effects or cyclic loading (Impact of Voids on Buried Utility Pipes Subjected to Surface Traffic Loading). Therefore, These will support the main findings of this research, particularly the academic / intellectual contribution