Investigation on scour process around bridge foundations considering soil particles and layer distributions

Abstract

Evaluation of scour depth is essential but challenging for the design and surveillance of bridges. The current engineering practice is primarily based on empirical equations. However, without considering geomechanics concepts, these methods are not always reliable, especially when utilised under different geological conditions. This paper introduces a new approach based on the geomechanical equilibrium concept, i.e. erosive force versus the erosion resistance. This analysis procedure incorporates the geomechanics concepts, and it can be solved by coupling computational fluid dynamics and soil particles. Based on numerical investigations considering soil particles, cases of scour prediction considering soil layer distributions have been carried out. With this concept, scour processes in layer-distributed soils and under different flood consequences have been analysed. It can be applied to investigate the scour process considering layered soils with different erosion resistance distributions and various hydraulic conditions. It is found that the proposed model can provide reliable results and explain a few scour phenomena, which are difficult to explain with traditional models.

Keywords:

• Bridge scour
• scour estimation
• geomechanical equilibrium
• scour resistance
• soil distribution

Acknowledgement

This work was supported by the National Natural Science Foundation of China (Grant No. 51908421), and “Chen Guang” project supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation (Grant No. 19CG21). Financial support from the organisations is gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.