A Risk-Based strategy for the Scour Analysis around bridge piers

Abstract

Local scour around bridge piers, especially during high floods, has been a critical issue for both the safety and serviceability of bridge foundations for decades. The objective of this study is to implement a risk-based strategy to account for local scour near the bridge piers. The methodology comprises of four fundamental steps wherein the first step involves evaluating hydrological hazards of an extreme nature. To precisely estimate the behavior of the river, the second phase uses several flow properties and depth of scour. In the third phase, the risk of scour connected with the bridge is evaluated by comparing the scour depth (DT) with foundation depth (DF) with a prioritizing factor (PF) which aids in determining the qualitative assessment of the scour risk. Lastly, an assessment of the risk of scour rating is assigned to find out the severity of the scour risk for the bridge piers. The present research discusses the incorporation of uncertainty in hydrological modeling through a predictive approach in the definition of the return period. To simulate flow parameters and assess bridge scour, the HEC-RAS program is utilized which incorporates a scour module. The study concludes with a qualitative evaluation of the impact of scouring on bridge susceptibility and safety. A case study on the Netaji Subhas Bridge across the Gomati (Gumti) river, Tripura served to validate the risk-based technique and it has been suggested that it can be effectively integrated into routine schedules for bridge examinations as a reliable risk management tool to avoid disastrous incidents.