Analysis Of3-D Finit Element In Steel-concrete Composite Continuous Box Girder Of Hongkong-Zhuhai-Macau Bridge With Construction And Service Stages

The schemes of non-navigable span in shallow water area of Hongkong-Zhuhai-Macau Bridge use85-m span steel-concrete composite continuous beams with6-7spans one continuous unit and the designed service life of the bridge will be120year.The bridge use the construction technology of large segment integral lifting,converting simply-support in continuous,fulcrum lifting-up and fallbacking, stretching prestress of bridge deck in negative moment area. The composite continuous beams experienced different system transformation. Change of construction order would influence the internal force of continuous beams. At present plane finite bar elements can be used to analyze the composite continuous beams. Stress of concrete bridge deck and steel box girder can be obtained by section conversion and plane section assumption,but it is difficult to understand and master distribution characteristics of stress in space definitely.it is necessary to analyze the stress distribution characteristics of composite continuous beams and variation law.The software ANSYS is used to built refined finit element model of composite continuous beams with background of Hongkong-Zhuhai—Macau Bridge.The composite continuous beams is analyzed systematically at the stages of large segment integral lifting, converting simply-support in continuous,rising and of fallbacking fulcrum and service stage according to construction order, conditions divided and load combined. The results show that bridge structure stresses definitely, the distribution of internal force of the structure is reasonable,the stress and deflection of structure is in the allowable rang.The design of bridge is reasonable and the results meet standard requirements. The result have theoretical significance and practical significance to grasp internal force characteristic of composite continuous beams and raise the level of analysis on composite continuous beams. There were main contents and results of research as follows:(1)The element she1163is used to simulate steel box girder,element solid45is used to simulate bridge concrete deck,element linkl0is used to simulate prestressed tendons and element beam188is used to simulate brace. Composite continuous beams is analyzed accuratly at each construction stage to obtain internal force characteristic of structure.(2)The bridge is analyzed under live load, temperature effect and support settlement at service stage according to6×85m spans refined finit element of bridge at finished bridge state.The result of stress distribution characteristics of composite continuous beams and variation law is obtained under the the worst combination of loads.(3The side span of bridge with shear studs bearing unfavorable load is choosed to analyzed to research the internal force distribution characteristics of shear studs in axial direction of bridge. Spring element combin39is used to simulate shear studs. Boundary conditions of cutting lines on the full bridge is applied to boundary conditions of single span finit element model to analyzed internal force characteristic of shear studs in space.