【作者】 张阳；

【导师】 邵旭东；

【作者基本信息】 湖南大学 ， 桥梁工程与隧道工程， 2006， 博士

【摘要】 本文对带波形钢腹板悬臂挑梁的钢—混凝土组合脊骨梁新结构进行了一系列试验研究和理论分析，主要包括组合脊骨梁在正载作用下的剪力滞效应、在偏载作用下的扭转特性、预应力大悬臂波形钢腹板组合挑梁受力性能以及组合脊骨梁极限承载力的研究。同时提出组合脊骨梁的实用设计方法，基本上解决了该种新结构在实际工程应用中的计算和分析问题。主要研究成果如下： (1)通过集中正载、均布正载作用下，简支和连续体系组合脊骨梁在弹性阶段的受力性能试验研究，证实了大悬臂组合脊骨梁受弯时存在明显的剪力滞现象，其最大正、负弯矩截面的剪力滞系数可达到1.2～1.35左右，悬臂混凝土翼板在初等梁理论计算中应折减成等效计算宽度，截面腹板应变沿高度的分布基本上符合平截面假定。同时建立了忽略波形钢腹板悬臂挑梁影响的组合脊骨梁剪力滞效应换算弹性模量法分析模型，提出多弹性模量、多剪切转角差函数，并考虑横向预应力影响的组合脊骨梁剪力滞效应计算方法，给出组合脊骨梁中混凝土板的有效分布宽度计算公式，理论计算结果与试验结果、空间有限元分析结果吻合较好。在此基础上进行了大量的参数分析，进一步探讨组合脊骨梁剪力滞效应的影响因素和变化规律，并定量分析了横向预应力对剪力滞效应的影响程度。 (2)带波形钢腹板挑梁的组合脊骨梁为小箱梁、大悬臂结构，截面在偏载作用下的扭转效应十分明显。本文采用乌氏第二定理，通过换算截面法，并在计算整个组合截面的广义主扇性惯矩I时加入大悬臂翼板的广义主扇性惯矩I_k，建立了考虑大悬臂混凝土翼板影响的组合脊骨梁截面刚性扭转翘曲应力和附加剪应力的计算方法。通过单点集中扭矩、两点集中扭矩以及均布扭矩作用下的组合脊骨梁扭转特性试验，验证了采用考虑大悬臂翼板影响的乌氏第二定理来分析组合脊骨梁的扭转效应较为合理，其结果偏于安全，精度可以满足工程要求。试验和计算结果分析发现，组合脊骨梁的约束扭转翘曲应力和腹板附加剪应力占对应弯曲应力的比例较大，扭转附加剪应力甚至超过了弯曲剪应力，故在实际工程设计中应予以特别重视。 (3)对大悬臂波形钢腹板挑梁并排支撑的组合桥面板进行了荷载横向分布和极限承载力的理论分析、空间有限元分析及试验研究，并与平面钢腹板组合挑梁对应的力学性能相比较。采用修正刚接梁法来分析悬臂组合桥面板的荷载横向分布问题，并假设横向分布系数随荷载作用位置的变化沿挑梁纵向呈三次曲线分布，从而可以方便地计算任意位置荷载作用下受载梁的荷载横向分布系数，并作了相应的参数分析。采用有限元方法对两种组合挑梁的极限承载力进行非线性全过程更多还原

【Abstract】 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更多还原