Abstract: The pile group received wider applications in the bridge design industry. Scour is one of the major failure mode of the bridge failures and it might results in large economical and life loss of the public. As a result, the scour depth prediction is critical to the bridge design. Currently, very few research on the influence factors on the scour depth are available. This paper presents a comprehensive review on the scour depth researches, test results and estimation methods. It is proposed that the residual soil above the local scour line is favorable to the scour depth reduction. A local scour depth estimation method is recommended by relating the local scour to the contraction scour.

Key words: Scour Depth, Group Pile, Experimental Studies, Empirical Formulas