scholarly journals Experimental Study on Seismic Performance of Old Masonry Walls

2020 ◽  
Vol 20 (6) ◽  
pp. 151-157
Author(s):  
Hoijin Kim ◽  
Zheongzun Yi ◽  
Jongsup Park ◽  
Junsuk Kang

Due to the increase in the frequency and intensity of earthquakes and the number of old buildings and in Korea, there is an expected increase in the damage to life and property. Therefore, we intend to derive an indicator to evaluate the risk level by conducting a seismic test on old buildings. An initial crack was generated in the masonry structure to reflect the deterioration. The effect of the deterioration on the building was subsequently analyzed by comparing it with the uncracked control group. As a result, the masonry wall, which was the specimen, satisfied the seismic performance, but local failure occurred along the initial crack in the specimen considering the aging. The safety was significantly decreased due to the occurrence of additional cracks. This demonstrates that the cracks caused by the aging of the masonry building greatly damaged the seismic performance of the building.

2021 ◽  
pp. 875529302098801
Author(s):  
Xin Wang ◽  
Qun Xie ◽  
Zhenli Wu ◽  
Fanyang Bu ◽  
Fei Wang

An experimental study was conducted to investigate the seismic performance of masonry walls strengthened using hybrid fiber-reinforced reactive powder concrete (HyFRRPC) as a coating. The proposed reinforcement technique was employed to improve the overall strength and structural integrity of the confined masonry wall. In order to guarantee the composite action between the masonry substrate and the coating material, material tests were conducted to achieve an optimal mixture for the HyFRRPC. Then, six full-scaled confined masonry specimens strengthened by HyFRRPCs with varied strengthening configurations were tested under in-plane quasi-static horizontal loading. The test and analysis results indicated that the proposed HyFRRPC-strengthening technique can effectively improve the lateral carrying capacity, displacement ductility, and energy dissipation capacity of masonry walls, and provide an optimal reinforcement. Finally, a simplified analytical model was also proposed for practical application.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jin-Ben Gu ◽  
Yi Tao ◽  
Ren Xin ◽  
Z. Yang ◽  
Qing-Xuan Shi

FRP composites have been used for strengthening RC and masonry structures for decades. However, the researches on repairing multistorey masonry structures using FRP grids were relative less. In the present paper, an experimental study on the seismic performance of multistorey masonry structure with openings repaired with CFRP grid is introduced. Specifically, a 1/3-scale three-floor masonry wall with window openings was tested under quasistatic action to simulate the seismic damages. The damaged masonry wall was then repaired by externally bonding CFRP grids to the areas where the cracks intensively occurred. The repaired masonry wall was retested under the same loading to investigate the seismic resistance and assess the recovery attributed from the CFRP grid repairing. The findings of this study showed that CFRP grid repairing could effectively postpone or even prevent the occurrence and development of cracking. The seismic resistance of the masonry, including shear capacity, energy dissipation capacity, deformability, stiffness degradation, and ductility, was restored. The application of CFRP grid may shift the failure mechanism of the multistorey masonry wall. The recommendation of repair scheme for the similar structures was also proposed in accordance with the findings of the present work.


2018 ◽  
Vol 180 ◽  
pp. 77-91 ◽  
Author(s):  
Jin Zhang ◽  
Hao Ma ◽  
Cheng Li ◽  
Qingfeng Xu ◽  
Weibin Li

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Syed Azmat Ali Shah ◽  
Junaid Shah Khan ◽  
Syed Muhammad Ali ◽  
Khan Shahzada ◽  
Waqar Ahmad ◽  
...  

Half-scaled reinforced concrete frame of two storeys and two bays with unreinforced masonry (URM) infill walls was subjected to base excitation on a shake table for seismic performance evaluation. Considering the high seismic hazard Zone IV of Pakistan, reinforcement detailing in the RC frame is provided according to special moment resisting frames (SMFRs) requirement of Building Code of Pakistan Seismic-Provisions (BCP SP-2007). The reinforced concrete frame was infilled with in-plane solid masonry walls in its interior frame, in-plane masonry walls with door and window openings in the exterior frame, out-of-plane solid masonry wall, and masonry wall with door and window openings in its interior frame. For seismic capacity qualification test, the structure was subjected to three runs of unidirectional base excitation with increasing intensity. For system identification, ambient-free vibration tests were performed at different stages of experiment. Seismic performance of brick masonry infill walls in reinforced concrete frame structures was evaluated. During the shake table test, performance of URM infill walls was satisfactory until design ground acceleration was 0.40g with a global drift of 0.23%. The test was continued till 1.24g of base acceleration. This paper presents key findings from the shake table tests, including the qualitative damage observations and quantitative force-displacement, and hysteretic response of the test specimen at different levels of excitation. Experimental results of this test will serve as a benchmark for validation of numerical and analytical models.


2014 ◽  
Vol 1065-1069 ◽  
pp. 1418-1422
Author(s):  
Tie Jun Qu ◽  
Rong Huan Xu

A full scale masonry model of two-floor and single bay was built in this paper and was strengthened by ring-beam and constructional column. And then pseudo-dynamic testing was conducted to study the time-history curves of displacement, velocity, acceleration response and restoring force in 7 degree rarely earthquake. Results show that the earthquake performance is steady and there are no visible cracks on the model after the testing. Windows and doors perform well because of the constraint of ring-beam and column, whereas failures often occurred when the structures were not strengthened. Seismic performance is largely improved by ring-beam and constructional column and the structure can resist 7 degree rarely earthquake.


2012 ◽  
Vol 226-228 ◽  
pp. 1098-1101
Author(s):  
Cheng Wang ◽  
Yong Kun Luo ◽  
Xiao Long Xu

With the rapid development of economy and the civil engineering discipline, the seismic performance of existing masonry wall can't satisfy the codes and regional seismic requirements. As a result, strengthening the earthquake resistance of it is put on the agenda. Using large-scale finite element software-abaqus, this paper analyzes different methods of strengthening masonry walls by constructional columns. Under the premise of the cross area of the columns used to reinforce is identical, it shows that the wall strengthened by bilateral constructional columns has a better seismic performance than by unilateral constructional column. The ductility coefficient of the former increases 49.4% than the original masonry, while the latter increases 26.3%. The bilateral constructional column could significantly improve the integrity and ductility of the masonry wall, so does the seismic performance. It has engineering sense for the strengthening work.


2019 ◽  
Vol 9 (20) ◽  
pp. 4354 ◽  
Author(s):  
Bin Chi ◽  
Xu Yang ◽  
Fenglai Wang ◽  
Zhiming Zhang ◽  
Yuhu Quan

In recent years, traditional masonry structures have been widely used in rural areas of China. However, they were found to have a poor seismic performance during earthquakes. In this study, a new prestressing technology was proposed and described in detail, and it was used in fully grouted concrete masonry wall systems to improve its seismic performance. The experimental work involved investigating the seismic response of four fully grouted reinforced concrete masonry wall systems, consisting of two symmetrically arranged reinforced block masonry walls, with different section types and prestressing technologies, when subjected to cyclic lateral force. Based on the test results, a flexure and ductile failure occurred in the specimens with a rectangular section, while a shear and brittle failure occurred in the specimens with a T-shape section. The prestressing technology had no significant effect on the failure state of the specimens, but it influenced the crack propagation, making cracks fine and densely covered. A symmetrical and obvious pinching effect was observed in the hysteretic response of all specimens. The average displacement ductility of the specimens varied within a range of values between 3.34 and 6.92, according to the section type of the specimens, and the prestressing technology improved the displacement ductility of the specimens. Moreover, the prestressing technology significantly improved the initial stiffness of the specimens, and the specimens with prestressing technology experienced a greater fall in the degradation of the normalized stiffness than the specimens without this technology throughout the loading process. In addition, the equivalent viscous damping of the specimens ranged between 8.2% and 10.8%, according to the section type. It could be concluded that the prestressing technology improved the energy dissipation of the specimens at the ascending stage, although it had no marked influence on the equivalent damping ratio of the specimens.


2013 ◽  
Vol 351-352 ◽  
pp. 1514-1518
Author(s):  
Yong Qun Zhang ◽  
Tao Wang

Assembly technology using prefabricated reinforced concrete (RC) members can effectively improve the seismic performance of existing masonry buildings. In this study, an existing masonry wall is enhanced by two pieces of prefabricated RC panels bonded on both surfaces of the wall. In order to guarantee the co-action between RC panels and the masonry wall, three techniques are employed, specifically, RC dowelling keys, grouting agent, and post-cast concrete bands. To investigate the interaction and force transmission between the two components, this study builds sophisticated finite element models and conducts nonlinear analyses to simulate the quasi-static cyclic tests. It is demonstrated that the proposed retrofitting technology effectively improves the seismic performance of existing masonry walls. The strength of existing walls increases 3-4 times and the stiffness increases 2-3 times, so that the requirement of current seismic design code is satisfied.


2019 ◽  
Vol 8 (4) ◽  
pp. 4680-4684 ◽  

The research aims at conducting a quality research with Reinforcement of a hollow brick wall. The empty internal sections significantly lower the dead load. With a better surface finish, the side of the block was cast, minimizing the cost of plastering. Several sample mixes are tested to achieve a finished surface. The respective frames were cast with and without reinforcement and the test results were compared. The blocks were used to build masonry walls and ' load-bearing strength ' of the walls was tested. It is possible to use the reinforced hollow block as a load-bearing wall. Nearly 75 percent of the deaths related to the earthquake in the last century,Buildings have collapsed, the majority of which (more than 70 percent)is due to the collapse of buildings made of masonry. Most of the properties in India are Unreinforced Masonry (URM) buildings that are weak and vulnerable even under moderate earthquakes and that function on the wall due to high wind forces, causing severe damage to high wind loads and it is recognized that Reinforced Masonry Building has many advantages over unreinforced masonry building.The use was very limited in Indian building practices and there are still no approved codes and shear walls were used in most constructions, even in mild earthquakes, instead of reinforced masonry walls


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