混凝土圆形冲切板的强度与变形计算

The strength and the deformation of circular concrete slab subjected to punching shear

通过试验验证,圆形混凝土板在冲切破坏之前发生的变形主要是弯曲变形,该变形反映了板在各个受力阶段的抗弯性能,也在很大程度上直接影响着冲切锥面上的应力分布和板面钢筋的抗冲切能力.建立了考虑受弯变形的板冲切破坏机构,提出板的极限强度由冲切锥抗冲切力和板在冲切时的抗弯能力组成.并对圆形冲切板的挠度分阶段进行了计算.对冲切板强度和变形的计算结果与实测值吻合良好.

Based on the tests, the strength and the deformation of reinforced concrete circular slab subjected to punching shear are investigated. The author points out that the deformation of slab before punching shear failure is caused by bending moment. The deformation not only reflects the flexure behavior of slab at every loading stage, but also affects the stress status on the surface of punching shear cone and affects the ultimate capacity of the slab. In this paper, the collapse mechanism considering bending deformation of punching shear slab is established. The author also points out that the final strength of punching shear slab includes the punching capacity of failure cone and a part of flexure strength of the whole slab. At the same time, the deformations of punching shear slabs at three loading stages before failure are calculated. The comparison shows good agreement between the theoretical values and the testing curves.