The Safety Analysis of Large Bridge Cushion Cap Suspension Box-Cofferdam during Pumping

As the extensive application of the elevated pile cushion cap in deep water, the construction method of suspension box-cofferdam develops increasingly on bridge construction in China. But the temporary extraordinarily construct is acted by static load such as rising force, hydrostatic pressure and structure gravity as well as dynamic loads such as wave force, water flow. Taking the practical program for example, this paper calculated the member stress of suspension box-cofferdam during pumping stages by finite element software package. To judge the security of the whole device, the detection of suspension box-cofferdam unit is done and the test to determine the bond tress of bottoming concrete is executed. Some conclusions are given based on these analyses. The section of other component can be decreased when the vulnerable connective area and the local super pressure-containing members are stiffened. And the bond coefficient 0.1 MPa is lower so that 0.2MPa is proposed to be advantage for the economy.