Research on local scour depth calculation of roadbed along river

Based on analysis of the factors affecting subgrade local scour along the river such as condition of stream,condition of bed form,geometric boundary condition of river,water depth and speed of every section,scour depth of parapet,the progress of scour and the form of stream near parapet were observed through the way of field model experiment.Aimed at roadbed scour along river of bad channel concave bank,authors contrasted existed formula accounting for scour depth,and found the formula accounting for the maximal local scour of bad channel concave bank to the roadbed along river after setting up parapet,by the mean of dimensional analysis.Relyed on the model experiment,authors made a quantitative analysis to reduce scour action of apron.Based on the observed result of experiment and the way of dimensional analysis,authors also got the formula accounting for the maximal local scour of the roadbed along river after setting up apron.The research result can be employed for engineers in the determination of the protection works foundations.