考虑梁板相互作用的现浇混凝土肋梁楼盖静力试验与理论分析

为研究现浇混凝土双向板肋梁楼盖梁板的相互作用，对柱支承混凝土双向板肋梁楼盖中的中区格板和边区格板模型进行了竖向加载试验，观测了这两种区格板模型中板、梁及柱的裂缝发展及破坏过程；分析了梁、板的荷载-挠度曲线以及板、梁和柱的荷载-钢筋应变曲线；采用线弹性理论、塑性理论和等效框架法分别计算了板控制截面的弯矩值并与试验值进行比较。根据试验与分析，对楼盖结构中梁与板的相互作用进行了分析。结果表明：这两种区格板肋梁楼盖模型均发生梁 板破坏模式；按线弹性理论和塑性理论（板破坏模式，不考虑梁板相互作用）所得板控制截面弯矩值与试验值差别较大，而按等效框架法和塑性理论（梁-板破坏模式，考虑梁板相互作用）所得弯矩值与试验值吻合较好。按塑性理论的梁 板破坏模式，分析了这两种区格板楼盖的极限荷载，分析结果与试验结果比较吻合。

Experimental and theoretical studies on interaction of beam and slab for cast-in-situ reinforced concrete floor structure

In order to study the interaction between beams and slab of the cast-in-situ reinforced concrete floor structure, two kinds of lattice two-way slabs which are at the centre and edge of the floor were tested step by step under the uniformly distributed load. Development of cracks on slab, beam and column was observed. The load-deflection curves of the beam, slab and the load-strain curves of steel bars in the beam, column and slab were analyzed. The bending moments of slab under the uniformly distributed loads calculated by the elastic theory, the equivalent-frame method and the limit theory were compared with the experimental results respectively. Based on the results of experiments and analysis, the interaction between beam and slab of the cast-in-situ reinforced concrete floor structure was studied. The results show that both two kinds of lattice two-way slabs experience the beam-slab failure; the two-way slab moment at the critical section calculated by the elastic thin plate theory and limit analysis method for slab failure mode (ignoring the interaction of beam and slab) differ significantly from the test result, and the moment obtained by the equivalent-frame method and the limit analysis method for beam-slab failure mode (considering the interaction of beam and slab) match well with the test result. Based on beam slab failure mode, the ultimate load formulas of these slab structures were proposed, and the value calculated by the proposed formulas conform well to the experimental result.