Out-of-plane mechanical behavior and theoretical analysis of concealed column timber frame infill wall

Abstract

The traditional dwellings feature thick infill wall (IW) with timber frames (TF) embedded within, forming a concealed column timber frame infill wall (TF-IW) system. Due to the lack of effective tensioning between the concealed column TF and IW, the IW is prone to out-of-plane (OOP) collapse under seismic action. To improve the connection performance between the TF and IW, a reinforcement method using embedded reinforcement element was proposed and designed. Four groups of 1:2 scale concealed column TF-IW specimens were designed, with the number and position of embedded reinforcement element as parameters. By studying the mechanical properties and deformation characteristics of each specimen, the arrangement principles of the embedded reinforcement element were determined. Additionally, the mechanical properties and deformation characteristics of the concealed column TF-IW were further studied using ABAQUS software. Based on this, a simplified calculation model for the bearing capacity (OOP) of IW was established, considering factors such as crack height, IW thickness, IW width, mortar strength, and boundary conditions. The results show that the calculation results are in excellent agreement with the experimental results. The study indicates that the mortar strength and the constraint effect of the beam on the IW have a minor impact on the bearing capacity (OOP) of the IW, increasing it by 9.3 % and 2.4 %, respectively, while the constraint effect of the TF column on the IW and the height of the cracks in the IW have a significant impact, increasing the bearing capacity by 69.7 % and 34.4 %, respectively. The research findings can provide a theoretical basis for the reinforcement design of concealed column TF-IW.