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为研究钢-混凝土空间壳体结构在静力荷载下内力响应、破坏过程与失效机理,以球面钢混凝土组合肋壳为对象,设计并制作整体结构和组合肋网2个缩尺模型,节点施加集中荷载进行结构破坏性试验。加载初期,两个试件变形均很小,整体结构模型中薄壳主要承受薄膜压力,组合肋中为轴压力;随着荷载增大,在组合肋壳加载壳面区域附近出现微小裂缝,组合肋网中加载点附近区域的混凝土与钢肋间出现微开裂。当壳面顶部出现交叉型裂缝,在一个加载点混凝土壳面压碎,下部组合肋节点混凝土部分也被压碎,在加载点附近形成局部塌陷区时,结构发生破坏;组合肋网模型中加载点处出现组合肋节点混凝土压碎,钢肋板出现局部褶皱,与圈梁相交的组合肋中钢肋板与混凝土间出现裂缝。试验结果表明:组合肋壳发生局部强度破坏;组合肋网由于局部杆件失效而发生破坏,试验测得组合肋壳最大承载力约为组合肋网的3倍,两个试件的荷载—位移曲线都表现出较好的延性。
In order to study the internal force response, failure process and failure mechanism of steel-concrete space shell under static load, two scale models of the whole structure and the combined rib net are designed and fabricated with the composite steel shell of spherical steel concrete. Concentrate the load for structural destructive testing. At the initial stage of loading, the deformations of the two specimens are very small. The thin shell in the overall structural model is mainly subjected to the film pressure and the axial pressure in the combined ribs. As the load increases, tiny cracks appear near the shell surface of the combined rib shell. Cracks in concrete and steel intercostal spaces near the loading point in the ribbed network. When the cross-shaped cracks appear on the top of shell, the concrete crust is crushed at one loading point and the concrete at the lower part is also crushed to form the partial collapse area near the loading point, At the point, the concrete of the composite rib node crushed, the local fold of the steel rib appeared, and the crack between the steel rib and the concrete of the combined rib intersecting with the ring beam. The experimental results show that the local failure of the composite rib shell occurs. The failure of the composite rib mesh due to the failure of the partial bar results in the maximum bearing capacity of the composite rib shell being about 3 times that of the combined rib mesh. The load-displacement The curves show good ductility.