论文部分内容阅读
建造了一个4层现浇无粘结预应力混凝土空心板柱结构的1/4比例模型,分别进行地震前第3层楼板弹性范围内的荷载试验和地震后第1层楼板极限荷载试验,通过测量楼板挠度、钢筋应力及空心楼板的裂纹发展情况,探求预应力混凝土空心板柱结构地震的损伤破坏,楼板的承载能力的变化情况。试验结果表明,在相同荷载作用下,楼板跨中、平行布管方向预应力暗梁和垂直布管方向预应力暗梁跨中地震后挠度均大于地震前。空心楼板的整体性较好,强烈地震对楼板的刚度响应较小,楼面承载力试验过程仍可划分为三个阶段:弹性阶段,开裂扩展阶段和破坏阶段。地震对垂直布管方向预应力暗梁刚度影响大于平行布管方向预应力暗梁,垂直布管方向预应力暗梁跨中挠度地震后比地震前增大程度明显大于平行布管预应力暗梁。基于前述试验结果,并考虑空心楼板的裂纹发展情况,建立了空心楼板极限荷载状态下的塑性铰线分析模型,计算空心楼板的极限荷载略小于试验结果,计算结果与试验数据吻合较好。
A 4-layer model of 4-story cast-in-place unbonded prestressed concrete hollow slab column structure was constructed. The load test in the elastic layer of the third floor before earthquake and the ultimate floor load test in the first floor after the earthquake were carried out respectively. The deflection of the floor, the stress of the steel bar and the crack development of the hollow slab are measured to investigate the damage and destruction of the prestressed concrete hollow slab structure and the change of the bearing capacity of the slab. The test results show that under the same load, the deflections of the prestressed concealed double-girder and the prestressed hidden beam in the vertical direction of the pipe are greater than those before the earthquake. The integrity of the hollow floor is better. The strong earthquake response to the stiffness of the floor is smaller. The test of the bearing capacity of the floor can still be divided into three stages: the elastic stage, the crack expansion stage and the failure stage. The influence of earthquakes on the prestressed dark-wall stiffness of the vertical pipe is greater than that of the parallel pre-stressed concealed steel pipe in the direction parallel to the pipe. After the earthquake, the increase of the pre-stressed dark- . Based on the above experimental results and taking into account the development of cracks in hollow slab, the plastic hinge analysis model of hollow slab under ultimate load was established. The ultimate load of hollow slab was calculated to be slightly less than the experimental one. The calculated results are in good agreement with the experimental data.