Analysis of main crack inclination angle of cast-in-situ slab in reinforced concrete beam-column-slab exterior joints(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2017年03期
- Page:
- 82-89
- Research Field:
- 桥梁与隧道工程
- Publishing date:
Info
- Title:
- Analysis of main crack inclination angle of cast-in-situ slab in reinforced concrete beam-column-slab exterior joints
- Author(s):
- XING Guo-hua; LI Wei-wei; XIE Peng-yu; LIU Bo-quan
- School of Civil Engineering, Chang’an University, Xi’an 710061, Shaanxi, China
- Keywords:
- structural engineering; frame joint; plane stress; Ritz method; crack; angle
- PACS:
- TU375
- DOI:
- -
- Abstract:
- Cast-in-situ concrete slab greatly influences the mechanical behavior of reinforced concrete beam-column joint. But its seismic mechanism is not yet clear. And under low-cyclic revised loading, failure of cast-in-situ slab after forming main cracks is one of the failure modes of reinforced concrete beam-column-slab exterior joints without containing lateral beam. Aiming at solving these problems, mechanical behavior of reinforced concrete beam-column-slab exterior joints was studied under earthquake loading, junction stress between cast-in-situ slab and frame column was analyzed, and analysis of inclination angle of the main crack of cast-in-situ concrete slab of frame exterior joints could be simplified as a plane problem by assuming the slab would not bear the force generating from frame beam. Based on Ritz method of displacement variational method in elastic mechanics, a simplified mechanical model of main crack inclination angle of cast-in-situ slab in exterior joints was put forward by considering mechanical behavior of beam-column-slab exterior joints as a plane stress problem and ignoring stress and strain along the thickness direction of cast-in-situ slab. By calculating the stress state of failure point when cast-in-situ slab cracked and analyzing the unit of failure point, the angle of principal plane was calculated, that is, the failure angle of main crack formed at the intersection of cast-in-situ slab and frame column. The results show that theoretical values of inclination angles of the main cracks of cast-in-situ concrete slab in reinforced concrete beam-column-slab exterior joints under low-cycle revised loading are 34.05°and 34.19°respectively, which agree well with the experimental results. The suggested simplified mechanical model can be utilized to analyze the stress of reinforced concrete frame joints under strong earthquake attack.
Last Update: 2017-06-06