An Experimental Study on the Local Protection Measures of a Bridge Caisson

This study performed hydraulic model experiments on the local protection measures of a bridge caisson. The purpose of this study is to understand the scouring phenomenon, protection efficiency and feasibility between the various protection measures as a reference for protection design of bridge local scouring. According to the bridge caisson on site, the in-situ check dam and planned three protection measures, eleven sets of experiments were designed and carried out. In addition, sediment supplement from upstream was also simulated. The sandy bed forms around the model bridge caisson were measured before and after each test. Also, the bed form variations were measured from the side of the flume to understand the influence of the check dam and the protection measures. From the experimental results, it is discovered that the existence of the check dam in the downstream has the strongest influence on bed forms and local scouring depth. Among the simulated protection measures, the effectiveness of the protection using circular piles is shown unsatisfied. All the other protection measures are shown having some certain degree of effectiveness.