# Punching Shear Stress in Post-Tensioned Transfer Plate of Multi-Story Buildings
## 2 Literature Review  
Analytical studies have been conducted on the analysis method and design of post-tensioned transfer plate systems. [PERSON] et al. (2016); [PERSON] et al. (2016); [PERSON] et al. (2016) conducted studies on the post-tensioned transfer plate for a residential building with a height of 25 stories. In this study, the separated analysis model in which the upper shear wall was replaced with equivalent line loads was used. The equivalent line loads were determined from axial force and bending moment of the upper shear wall. Based on the analysis results, the efficiency of post-tensioned transfer plate was compared with that of conventional transfer plate. It was reported that the post-tensioned plate thickness could be reduced by about 14% compared to the conventional transfer plate, and the amount of concrete and reinforcement could be reduced by 13% and 39%, respectively. However, in this study, the analysis was performed using the separate analysis model only. Several experimental and analytical studies for transfer structures have also been conducted on down-scaled shaking tables to analyze seismic behavior of high-rise buildings with a transfer floor ([PERSON] et al., 2016; [PERSON] et al., 2016; [PERSON] et al., 2016). [PERSON] et al. (2016) experimented using a 1:20 scaled model of high-rise residential building (34F) with a transfer plate system. The structures below and above the transfer plate were designed with  
Figure 1: The analysis and design process for residential building with the post-tensioned transfer plate. three stories of frame structure and 31 stories of shear wall structure, respectively, and the thickness of the transfer plate was designed to be 2.7 m. The scaled model was installed on the shaking table and four level ground motions were applied. As a result of the shaking table test, a noticeable vibration was not observed at the minor level (0.02-0.06 g), a little vibration and several cracks were observed at the right top of the transfer plate at the moderate level (0.08-0.14 g). At the major level (0.15-0.2 g), considerable vibration and cracks were observed at the top of the transfer plate and above the middle height. At the severe level (0.25-0.34 g), failure at just above the transfer plate occurred. As a result of excitation of various levels of ground motion, it was found that most of the damage or failure had occurred in the shear wall at the top of the transfer plate. In this study, dynamic behavior and failure patterns of high-rise residential buildings under various levels of ground motion were analyzed, but no analysis on shear behavior of transfer column-plate connections was conducted. [PERSON] et al. [8] also experimented with a 1:4 scaled model of a flat-shape plan building with 17 stories of the shear wall above and a single story of frame below. The cracks on the bottom face of the transfer plate under four levels of ground motion were observed. No cracks occurred under acceleration of 0.02-0.04 g, and several cracks began to occur at the bottom face of the transfer plate at levels of 0.08g-0.16 g. Moderate damage was observed under acceleration level of 0.32 g, and severe damage was observed at the acceleration level of 0.64 g, but did not collapse. In this experimental study, it was found that damage can occur in the transfer plate under lateral load (seismic load). Nevertheless, the shear behavior of transfer column-plate connections under seismic load had not been analyzed. [PERSON] and [PERSON] [9] conducted a 1:2.5 scaled model experiment to analyze the performance and failure of the transfer girder. The transfer girder was designed using two methods, one based on ACI code and the other using the strut-tie model (Figure 2a), and the design was verified with the experimental results. For the design method according to ACI code, the design was carried out replacing the wall parallel and orthogonal to the transfer girder with distributed load and concentrated load, respectively (Figure 2b).