Resistance Analysis of Open Caisson Towing on Water in the Construction of the Large Scale Bridge

In order to solve the towing problem on water of the open caisson in the construction of the large scale bridge efficiently, combining with the towing operation project, the dragged open caisson and environmental data, etc. we design and produce the open caisson physical model and configure the test environment, use the force cell to collect real-time ex- perimental data, analyze and demonstrate the towing resistance of the open caisson. Use the experimental data and the model of resistance similarity transformation to calculate the resistance, while the towing speed is 1m/s, 2m/s and 3m/s, the resistance is 323 KN, 724KN, 1398KN in the straight test mode and the resistance is 365 KN, 861KN, 2326KN in the transverse test mode. The results show that the resistance of the open caisson has certain growth trend with the towing speed rising, which both have large correlation, and the resistance of transverse situation is larger than straight mode. With the development of economic construction, by 2020, there will be more than a hundred large scale bridges are built in China. In the construction process of the large span bridges, most of them are constructed and piece to- gether directly in the bridge waterway, therefore, many op- erations are involved in the construction technology of bridge pier, such as the construction, towing and positioning of open caisson, etc. The most complex and challenging op- eration is the towing operation of the open caisson, which mainly influenced by its own scale, stress characteristics, external environments, towing force and other factors. As a general rule, the open caisson have no sailing power with their own, they need the external assistance to keep their sailing, so a certain number of tugs are required during the towing operation of the open caisson. In consideration of the complexity and risk in towing operation, we have to fully research the resistance of the open caisson in towing opera- tion, and equipped with sufficient tug horsepower. In recent years, there are also some studies on the resistance of cais- sons have been carried out.