Analysis On Steel Cofferdam With Nonlinear Finite Element Method And Secondary Development Of Marc

With the cross-river lakes, and seas building of the bridge construction, deep-water foundation to develop in the direction of greater and deeper, the construction of underwater piers and abutments is the important technical aspects throughout the whole construction process.The river width, depth, flow urgent conditions, the steel cofferdam as a temporary structure to prevent water creating a anhydrous environment for the platform construction and as a form of side template for platform concrete pouring, the scale of its construction is unprecedented. Because of the large scale structure of the cofferdam, as well as its own complex load and the non-linear form under loads, there are many uncertain factors. Therefore, it is necessary to have a further study of the cofferdam.The subsealing concrete construction is the key process in the steel cofferdam (suspension-box) construction for the bridge deep-water foundation.Starting from different construction steps, considering the nonlinear contact between steel cofferdam ubsealing concrete and pile steel pipe, research the pile spacing,the steel pipe diameter,the number of pile and the depth of cofferdam in water on the impact of bond load through building three-dimensional finite element model. And find out the main factors of which the pile affects the thickness of ubsealing concrete. It guides to determine the thickness of the subsealing concrete.Taking a single double-wall combined steel cofferdam as an example, consider the hydrostatic pressure, the earth pressure and the hydrodynamic pressure, select the end of subsealing concrete construction, pumping process, the end of pumping pre-construction, construction of Pier before the conversion, and other important support for the calculation of the processes of the status, using Marc program to do the overall nonlinear finite element analysis and buckling instability analysis for the steel cofferdam. Through the analysis found the weak position in the structural design, and take corresponding measures to strengthen.Marc software has a good extended performance, in view of practical problems, it introduced the use of subroutine and the development of user-defined menu. These successfully applied in a number of research projects, and achieved good effects.Theses studies show that using the finite element method to understand the forced state and determine the thickness of the subsealing concrete has very good results; used large finite element program for steel structural cofferdam system nonlinear finite element analysis and buckling instability analysis, the results have practical significance.