The Analysis Of Load Combination And Mechanical Properties Of Huaihe Super Deep Double-Wall Steel Cofferdam

The development of large span river bridge makes the construction of deep-water foundation more and more common,which also put forward higher requirements for the construction technology of waterproof cofferdam in rivers.Double-wall steel cofferdam structure is an important form of waterproof cofferdam,which has been widely used in deep water foundation construction.However,there are two shortcomings in the design of steel cofferdam.On the one hand,the conservative model of the cofferdam is used to calculate the bearing capacity of the cofferdam,and the whole structure of the cofferdam is neglected;On the other hand,there is no special steel cofferdam design specifications for reference,the load values and combinations of cofferdam design can only refer to the relevant data definition,which is lack of unity.Because the construction of double-wall steel cofferdam structure is complex and uncertain,it is very important for the determination of the most unfavorable combination of construction load.In this paper,by referring to the relevant norms,the load value and mode of application of Cofferdam structure in the construction can be deduced.Through the finite element software Midas civil,to establish double-wall steel cofferdam model,simulate the actual construction of the various loads,assemble all the loads,and select four conditions of the cofferdam implantation,back cover concrete pouring,pumping half and pumping the end.Finally the stress characteristics of the cofferdam structure under different construction conditions are obtained.By comparing the measured results with the numerical results,the stress characteristics of the cofferdam structures are verified,and the differences are found in the comparison,and the coefficient of the load combination can be reasonably modified.In this paper,the whole model of backfill concrete and steel tube is established by finite element software Midas FEA,and the distribution law of contact stress is obtained,which also provides some reference for the design of cofferdam structure.In this paper,the influence of the spacing between the partition plate and the spacing of the horizontal system on the stress of the cofferdam is discussed,which provides a reference for the optimization of the double-wall steel cofferdam structure.