Construction Risk Analysis of Suspension Box-Cofferdam in Concrete Casting Stage

As a temporary extraordinarily structure, the large bridge elevated-pile cushion-cap suspension box-cofferdam is acted by static loads and dynamic loads. The structure with dimension of 120 m long, 52.3 m wide, 16.5 m high is in bad risk of failure after the first layer cushion cap concrete total 3 m high, gross weight 3.7 times 10⁴ ton fluid body is poured. This paper calculated the stresses of steel suspension box-cofferdam member and bottoming concrete by finite element method. The detection of suspension box-cofferdam unit was done and the test of bond tress of bottoming concrete, reaching to 0.63 MPa, was implemented. Some conclusions, which could provide very valuable reference to the other similar projects, are given. The stress state of some components is optimized when wall body is in adverse state. The section of other component can be decreased when the vulnerable connective area and the local super pressure-containing members should be stiffened. And the resistance to gliding bond coefficient suggestion is presented.