Experimental Study And Analysis On The Behaviors Of Steel-Concrete Composite Spine Girder With Large Cantilevered Beams Possessing Corrugated Steel Web

In this paper, a series of experimental researches and theoretical analyses on the new steel-concrete composite spine girder with large cantilevered beams possessing corrugated steel web (SCCSG), including primarily the shear lag effects of composite spine girder under symmetrical loads, the torsional behaviors of it under eccentric loads and loading characteristics of prestressed large cantilevered composite beams with corrugated steel web as well as the ultimate bearing capacity of SCCSG, have been studied. Furthermore, the applied design methods are invented, and it is resolved basically that calculations and analyses of the new construction applied practical projects. The main achievements are summarized as following:(1) Based on the experimental study on elastic behaviors of continuous and simply-supported composite spine girder under the concentrated and uniformly distributing symmetrical loads, respectively, it has been confirmed that the obvious shear lag occurred in large cantilevered composite spine girder bearing bending moment, in which the shear-lag coefficients of maximum positive and negative bending-moment sections in SCCSG were achieve to 1.2 — 1.35 or so. During calculation of elementary beam theory, width of concrete slab should be reduced to the equivalent width, and we conclude that the strain distribution along depth of cross-section accorded with Plane Section Assumption basically from the tests and analyses. At the same time, the analytical models are established based on conversion elastic modulus on shear-lag effect of SCCSG ignoring cantilevered beams with corrugated steel web, and a shear-lag computational method of composite spine girder is constructed in which the multi-modulus of elasticity, the multi-differential functions of maximal shear angle are utilized and the infection of transverse prestress is considered. In addition, the effective flange width of concrete slab is defined. The theoretical results consist with the experimental values and FEM values. To discuss more the infection factors and change rules for shear-lag effect of composite spine girder, a plenty of parameter analysis are carried out, moreover analyzed quantitatively the degree of transverse prestress influence the shear-lag effect.(2) As a composite structure with small box girder and large cantilever, the torsion of SCCSG under eccentric loads is observed. According to equivalent section method considering the contribution of generalized main fan-type inertia moment I_k...