scholarly journals Seismic Performance of Existing RC Structural Walls Retrofitted in Flexure by Wall End Plate

2021 ◽  
Vol 13 (2) ◽  
pp. 509
Author(s):  
Su-Yong Kim ◽  
Uijin Cho ◽  
Joo-Hong Chung ◽  
Baek-Il Bae ◽  
Chang-Sik Choi

A study was conducted for the flexural retrofit of an old apartment house composed of a reinforced concrete (RC) shear wall structure. For the shear wall, a vertical retrofit was performed to both ends of the wall targeting the slender wall to improve the flexural performance. The retrofit materials were steel plate, epoxy, and non-shrink grout, and they were connected to the existing shear wall using post-installed chemical anchors. The concrete at the wall ends was broken and retrofitted as much as necessary to maintain the shear wall’s length. The points to be noted are the fracture of the welded part of the flexural retrofit and the chemical anchor’s pulling. After the real scale specimen was fabricated by simulating the existing shear wall, the retrofit effect was experimentally verified by breaking the wall ends, retrofitting the ends, and applying repeated cyclic lateral loads. A total of three specimens were fabricated and retrofitted using steel plates and steel tubes. Since this experiment evaluated the flexural performance, the experiment was performed with a cantilever setting. The flexural retrofit effect using steel was analyzed through the load–displacement relationship, stiffness degradation, and energy dissipation, and through this, the bond of the retrofit and the behavior of the wall were verified.

2011 ◽  
Vol 368-373 ◽  
pp. 1943-1948 ◽  
Author(s):  
Liang Chen ◽  
Zhong Fan Chen

CTSRC structure is a new composite structural system for residential buildings and it consists of walls and floors which are made of the prefabricated steel skeleton and the infill of concrete. Four pieces of CTSRC shear wall specimens and one piece of RC shear wall specimen are tested under low cyclic lateral loads to study the final failure modes and analyze its structural seismic performance. It shows that the CTSRC shear wall structure possess adequate bearing capacity, fine seismic performance and ductility. CTSRC shear walls are better than RC shear walls in the seismic behavior, and it could replace traditional shear walls structure applying to practical engineering. Inserting ring used for connecting profile steel can transfer stress well and it is recognized as a reasonable construction measure.


2014 ◽  
Vol 919-921 ◽  
pp. 1012-1015
Author(s):  
Pei Song Liu ◽  
Liang Bai

Bottom frame-shear wall structure is a kind of special structure, due to the inharmonious relationship between the frame and masonry walls in bearing lateral capacity and deformation ability, the difference of vertical stiffness in the bottom frame-shear wall structure is bigger, so the structural seismic performance is poor. A six layer bottom frame-shear wall structure seismic strengthening project is established in order to contrastive analyze two kinds of reinforcement scheme, which are additional RC shear wall and additional buckling constraints. Calculation and analysis results show that through setting buckling constraint support in the bottom layer of reinforced concrete frame and selecting rational mechanical parameters, can increase lateral stiffness, reduce the lateral deformation and realize the effect of multichannel fortification. At the same time, the advantage of easy to implement is belong to bottom frame-shear wall structure.


2009 ◽  
Vol 25 (4) ◽  
pp. 803-819 ◽  
Author(s):  
Taewan Kim ◽  
Douglas A. Foutch ◽  
James Wilcoski ◽  
James M. LaFave

A rational approach for determining the response modification factor, [Formula: see text], has been applied to reinforced concrete (RC) shear wall buildings designed under current codes and standards of practice. The approach is founded upon the performance-based evaluation framework from the SAC project; however, new values for various parameters were derived specifically for RC shear wall buildings because the SAC parameters were for steel moment frame buildings. Typical RC shear wall buildings were designed consisting of solid, flexure-dominated structural walls for lateral load resistance and a flat plate floor system for gravity loads. The performance of each building was then evaluated by calculating the confidence level of achieving the design objective. The buildings designed per the current [Formula: see text]-value of 6 demonstrated good performances, meaning that the confidence levels of avoiding collapse were greater than the target value of 90%. The confidence levels for shear wall buildings with greater [Formula: see text]-values were also determined, suggesting that further study could provide the basis for justifying an [Formula: see text]-value of 7 for the special RC shear wall structural system.


2007 ◽  
Vol 348-349 ◽  
pp. 917-920
Author(s):  
Chang Sik Choi ◽  
Yun Cheul Choi ◽  
Hyun Ki Choi ◽  
M.S. Lee

A series of three shear wall specimens were tested under constant axial stress and reversed cyclical lateral loading in order to evaluate the seismic retrofit that had been proposed for the shear wall with the opening induced by remodeling. One of these specimens was tested in the as-built condition and the other two were retrofitted prior to testing. The retrofit involved the use of carbon fiber sheets and steel plates (a thickness of 3mm) over the entire face of the wall. The test results showed that the failed specimens had shear fractures and that two different types of retrofitting strategies had different effects on the strengths of each specimen.


2013 ◽  
Vol 423-426 ◽  
pp. 1506-1510
Author(s):  
De Jian Yang ◽  
Zong Chen

The structural system and seismic performance of the composite shear wall are analyzed based on the horizontal load model tests. The test models are three groups of combined shear walls with shear span of 1.5, including an ordinary shear wall, a shear wall with vertical steel plates and a shear wall with transverse steel plates. The finite element software ABAQUS is used to build the calculation model of the shear wall structure. And the analysis the influence of steel plates to bearing capacity, ductility, and stiffness of shear wall are carried out. The research results indicate that the combination shear wall has good seismic behaviors.


2013 ◽  
Vol 721 ◽  
pp. 714-719
Author(s):  
Cheng Bei ◽  
Shi Wei Li ◽  
Ray K.L. Su

Coupling beams are essential structural elements of reinforced concrete coupled shear wall to resist earthquakes and other lateral loads. But many current reinforced concrete coupling beams are insufficient in resisting lateral loads due to their bad ductility. So a test of retrofitting methods of deep coupling beams with steel plates since their good performance in the ductility and deformation was made to find ways of improving the ductility of the beams, and the results of this retrofitting method prove good because of the incensement of the ductility, deformation and strength of the beams.


2022 ◽  
pp. 136943322110606
Author(s):  
Xiao-ting Wang ◽  
Xi Chen ◽  
Tao Wang ◽  
Peng Pan ◽  
Qi-song Miao

A novel monolithic precast concrete shear wall structure system was proposed, with four connector types: “cast-in-site elbow reinforced concrete joints,” “dry connectors,” “shaped steel shear keys,” and “shaped steel boundary elements” based on welding process with stable and high quality. The first two connect walls horizontally and the other two connect walls between adjacent stories. A high precast ratio, over 60%, can be achieved. To evaluate the strength, stiffness, ductility, and energy dissipation capacity of the proposed system, a full-scale three-story model was tested quasi-statically in the two horizontal directions. The model showed strong spatial response, demonstrating sufficient strength and stiffness to resist severe earthquakes. The coupling beams suffered shear failure damage. The connectors sustained large internal forces, surviving under simulated severe earthquake conditions. The external thermal insulation layers remained firmly attached to the precast wall panels, satisfying the design objectives.


2012 ◽  
Vol 174-177 ◽  
pp. 2012-2015
Author(s):  
Xiao Long Zhou ◽  
Ying Min Li ◽  
Lin Bo Song ◽  
Qian Tan

There are two typical seismic damage characteristics to the masonry building with frame shear wall structure at first two stories, and the lateral stiffness ratio of the third storey to the second storey is one of the key factors mostly affecting the seismic performance of this kind of building. However, some factors are not considered sufficiently in current Chinese seismic codes. According to the theory of performance-based seismic design, the seismic performance of this kind of structure is analyzed in this paper by taking time-history analysis on models which with different storey stiffness ratios. The results show that when the lateral stiffness ratio controlled in a reasonable range, the upper masonry deformation can be ensured in a range of elastic roughly, and the bottom frame can be guaranteed to have sufficient deformation and energy dissipation capacity. Finally, according to the seismic performance characteristics of masonry building with frame shear wall structure at first two stories, especially the characteristics under strong earthquakes, a method of simplified calculation model for the upper masonry is discussed in this paper.


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