Evaluation of methods for estimation of scour in bridges.
Abstract
According to (Wang, Yu, & Liang, 2017) , scour of sediments around bridge foundations by the stream is
the most significant contributing factor for bridge failures. The scour failures tend to occur without prior
warning and have led to fatalities and economic loss every year. Flowing water can affect bridges by
eroding streambed or bank material. This scour can expose bridge elements, compromising bridge stability
and safety and leading to bridge failure. Bridges with foundations that are unstable for calculated and/ or
observed scour conditions are termed scour-critical bridges.
This study evaluated the scour condition of Bunoga bridge on river Mpanga using the Froehlich’s
Abutment scour equation (method) and HIRE Abutment scour equation, used to determine whether the
bridge and its elements are scour critical or not and results of different methods were assessed to ascertain
which was more suitable for Abutment scour evaluation on the case study and its specific characteritics.
After a review of findings and analysis, it was concluded that the Froehlich’s Abutment scour equation
was more accurate in Abutment scour analysis than the HIRE Abutment scour equation on the case study.
Chapter 1 introduces the bridge scour situation, problem statement, objectives of the study, justification
and scope of the study. Chapter 2 gives a moderately detailed description of the different forms of bridge
scour and methods of determining and evaluating bridge scour depths and computations necessary for
arriving at conclusive results. Chapter 3 gives the methodology that was used to evaluate bridge scour.
Chapter 4 gives the findings and analysis of the study. Chapter 5 gives the conclusions and
recommendations of the study.