NUMERICAL SIMULATION OF SCOUR AROUND COMPLEX PIERS IN COHESIVE SOIL

A chimera Reynolds-Averaged Navier-Stokes (RANS) method has been employed in conjunction with a scour rate equation for time-domain simulation of scour around complex piers in cohesive soils. The method solves unsteady RANS equations in a general curvilinear coordinate system using a chimera domain decomposition approach. The scour depth at each point of the streambed is determined in terms of the local shear stress using a simple scour rate equation. Calculations were performed for a model scale complex rectangular piers and a prototype circular complex pier configuration to illustrate the general capabilities of the method for prediction of combined contraction and local pier scours.