Study on scour around vertical large-size cylinder base due to combined action of wave and current

Jiang Mong, LI Lin-pu, Han Li-hua, ZHANG Ri-xiang

School of Civil and Hydraulic Engineering,Dalian University of Technology,Dalian 116024,China



Abstract:

Based on the mechanism of local scour around vertical large-sized cylinder due to combined action of wave and current,the sour morphology,scour process and the maximum scour depth around the cylinders are studied experimentally.The influence of various ocean environmental parameters on local scour around the cylinder is considered in physical model test.The experimental results indicate that the principal effect factors on the scour in fine-sand seabed are wave height,wavelength,current velocity,ratio of diameter to wavelength and ratio of depth to wavelength when the ratio of cylinder diameter to wavelength is from 0.2 to 0.8.In this paper,dimensional analysis theory is utilized to establish a theoretical equation for forecasting maximum scour depth around large-sized round cylinder base due to the combined action of wave and current.The results computed with the theoretical equation are compared with the experimental results,and found to be in good consistency.The results in this studies can be used to estimate the maximum sour depth around analogous structures.

Key words:  offshore  combined action of wave and current  large-sized cylinder  local scour

DOI：10.11916/j.issn.1005-9113.2011.04.010

Clc Number:TV12

Fund: