Comparative Research On Deck Schemes Of Through Steel Tied-double-arch Composite Bridge

Compared with other types of bridge, through steel tied-double-arch compositebridge shows several evident competitive advantages such as appealing design, greatspanning capacity, low architecture height and easy-quick construction. It’s anattractive solution especially for the100~160m span bridge across railways,expressways, urban rivers and arterial streets, where the demand of city landscape isusually high. Aimed at through steel tied-double-arch composite bridge, manyscholars have done correlational studies at home and abroad, but systematic theoryand studies of deck schemes are still rare. Based on the engineering background of aXKH bridge on a high-speed railway line and the same material consumption, thecomparative research systematically studied two deck schemes, which include thelongitudinal and transverse girder deck scheme and dense transverse girder deckscheme, of through steel tied-double-arch composite bridge. The main contents andresearch works include several aspects as follows:1.The numerical simulation methods of time-dependent relationship of concretesuch as shrinkage, creep and strength increase are studied for through steeltied-double-arch composite bridge. Meanwhile, the advantages and disadvantages offour kinds of simulated methods including isolate plate-beam element method, plateelement method, combined plate-beam element method and solid element method, areresearched comparatively in steel concrete composite bridge deck system, and thenthe simulated method of this article is identified.2.The mechanical models of the longitudinal and transverse girder deck schemeand dense transverse girder deck scheme for through steel tied-double-arch compositebridge are presented. The effect of deck schemes is divided into overall tension effectand local banding effect. For the first effect, tensioned tie beam will cause decksystem to extend, and for the other effect, relative banding effect will be causedbetween deck system and tie beams with the action of bridge load. According to theforce balance condition, using the beam grillage method, the approximate analyticalsolution of internal force and deformation of deck system with the action of the twoeffects are deduced.3.With the action of13load conditions, which involve the first phase load, thesecond phase of constant load, ZK live load, shrink of concrete, creep of concrete,train sway force, wind load and temperature load, simulation analyses of space finiteelement on the longitudinal and transverse girder deck scheme and dense transversegirder deck scheme for through steel tied-double-arch composite bridge are made tostudy stress state of full-bridge. Comparative studies are carried out between resultsof numerical simulation analyses and analytical solutions, and the results show thatboth has merely a difference of less than10%, it is used to verify the precision of the analytical solutions in this paper.4.The comparative study on the longitudinal and transverse girder deck schemeand dense transverse girder deck scheme is conducted to analyse self-vibrationcharacteristics and stability of through steel tied-double-arch composite bridge. Theresults show that, in terms of self-vibration frequency, dense transverse girder deckscheme is litter bigger than the longitudinal and transverse girder deck scheme, butmodal characteristics of the two deck schemes are roughly identical. The stability ofthe dense transverse girder deck scheme is better than that of the other scheme’s,while there are large differences for buckling modes in the two deck schemes.5.In this paper, the research results can provide beneficial reference for designand construction of through steel tied-double-arch composite bridge.