Studying the effect of partial blockage on multi-vents bridge pier scour experimentally and numerically

The local scour depth at bridge supports due to partial blockage on front of multi-vents bridge pier is studied experimentally and numerically. The existence of blockage such as debris and industrial wastes, leads to increase the local scour depth around bridge foundation and even bridge failure. The computational fluid dynamic program (SSIIM), is applied to simulate the scour around bridge supports. The numerical model used the finite-volume method to solve the Navier-Stokes equations. The k–ε turbulence model is applied to solve the Reynolds-stress term. The 3-D flow model has been verified by comparing the numerical simulation with experimental data. It was found that, the local scour depth by impermeable obstruction on front of one bridge pier depends on Froude number, and dimensions of obstacle. In addition, multiple linear repressions are used to propose empirical equations for estimating local scour depth at bridge supports. The results show good agreement between both of numerical and statistical simulations with experimental results. Keywords: Local scour, Pier, Abutment, Blockage, SSIIM, Hydraulic structure