Study on Prediction Method for Compression Scour Depth of River-Crossing Bridge

Abstract

AbstractRiverbed deformation caused by river-crossing bridge construction can be divided into compression scour and local scour. Compared with local scour, fewer studies have been made on the compression scour caused by bridge piers. It is noteworthy that, the compression scour can lead to riverbed scour of the whole cross section along a bridge site, which is obviously detrimental to the bridge foundation safety. Based on a summary of existing research findings, a prediction model for the compression scour of bridge piers is constructed, and the model is applied in predicting the compression scour depth of Shiyezhou River Bridge in the lower reaches of the Yangtze River. Firstly, the pier boundary treatment methods at different spatial scales are discussed. Subsequently, the selection method of flow and sediment processes is proposed from the engineering safety point of view, according to the flow and sediment characteristics on the lower reaches of the Yangtze River. Finally, the depth of compression scour around the upstream and downstream of Shiyezhou Bridge piers are predicted, and comparisons were made between the prediction depth of Shiyezhou Bridge and other existing bridges in the lower reaches of the Yangtze River. Comparisons show that the compression scour depth of Shiyezhou Bridge was basically equivalent to that of other bridges downstream the Yangtze River. The results indicate that the method for predicting the compression scour depth of bridge piers is reasonable and feasible, and the prediction of compression scour depth can provide technical basis for determining the embedment depth of the bridge pier foundation.