Firstly,the research results of the force transfer mechanism and mechanical behavior of bridge column and bent cap joint under seismic load are introduced.And than the specific provisions of domestic and foreign design codes and standards on the principal stress checking calculation of joints are analyzed and compared,and the adoption of the shear area Ajv,the equivalent cross-section Ajh that bears the axial force of the column and the longitudinal reinforcement tension Tc of the concrete column are discussed.Finally,a calculation analysis is conducted based on actual bridge engineering.The analysis result shows that the anchorage length of the longitudinal reinforcement of the column in the core area of the joint is closely related to the value of the principal stress of the joint,and should be calculated based on the actual anchorage length.When the main compressive stress of the joint between the prestressed bent cap and the column exceeds the limit,in addition to appropriately increasing the limit,the measures such as adjusting the prestressing degree,the anchorage length of the column main reinforcement,or the height of the bent cap can be also taken to improve it.In addition,the rigid joint can be formed by controlling the minimum reinforcement ratio of horizontal stirrups in the core area of the joint.
关键词
抗震设计/节点/预应力/名义主拉应力/名义主压应力/名义剪应力
Key words
seismic design/joint/prestress/nominal principal tensile stress/nominal principal compressive stress/nominal shear stress
维普
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