Experimental and numerical study on structural behaviour of precast concrete beam-column joints under column removal scenario

• Main Author: Bao, Yintong
• Other Authors: Tan Kang Hai
• Format: Thesis-Doctor of Philosophy
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Engineering::Civil engineering::Structures and design
• Online Access: https://hdl.handle.net/10356/172102
• Institution: Nanyang Technological University

Structural collapse incidents caused by extreme loads have attracted the attention of academia. In precast concrete (PC) structures, the relatively low integrity and robustness of the structural system caused by PC beam-column joints, may significantly influence the effectiveness of alternate load paths comprising compressive arch action (CAA) and catenary action (CA) to mitigate progressive collapse. However, there have not been comprehensive studies on collapse resistances of the existing PC beam-column joints and their effects on CAA and CA in substructures. To address these research gaps, experimental studies consisting of two series of tests were carried out in this thesis, to investigate the collapse performance of a total of 10 specimens employing four widely applied types of PC beam-column wet and dry joints under different column removal scenarios. Furthermore, advanced componentbased models for the various types of PC beam-column joints were developed for efficient macro-FEM simulations. Parametric studies were undertaken to investigate the effects of precast interface location, PC reinforcing details, cross-section of beam, boundary condition at beam ends and ductility of PC connections on mobilisation of CAA and CA of PC sub-assemblages. Apart from experimental and FEM studies, an easy-to-use analytical model was developed to predict CAA and CA of RC sub-assemblages under MCRS, incorporating varying horizontal restraint conditions, span-to-depth ratios and crosssection profile of the beam, as well as bending curvature of the two-span bridging beams. Furthermore, an iterative model and a simplified design method were proposed to predict the CAA of PC structures, incorporating the potential plastic hinge at the PC interface, various precast interface locations along the beam span, special precast reinforcing details and horizontal restraint conditions of the PC beams. Finally, a parametric study was carried out to shed light on the effects of various precast design details on CAA.