Retrofitting Effect of Unreinforced Masonry Walls Using FRPs

2010 ◽  
Vol 452-453 ◽  
pp. 765-768 ◽  
Author(s):  
B.I. Bae ◽  
B.K. Park ◽  
Hyun Ki Choi ◽  
Chang Sik Choi
Keyword(s):  
Evaluation Method ◽  
Shear Walls ◽  
Shear Wall ◽  
Shear Behavior ◽  
Unreinforced Masonry ◽  
Seismic Retrofitting ◽  
Fiber Reinforced Polymers ◽  
Masonry Buildings ◽  
Plane Shear ◽  
Masonry Shear Wall

Unreinforced masonry buildings have significant portion of existing and historical buildings around the world. Recent earthquakes have shown the needs of seismic retrofitting for these types of buildings. There are many types of retrofitting materials for URM(unreinforced masonry buildings) such as shotcrete, ECC and FRPs. Many engineers use many types of fiber reinforced polymers because these types of material enhance the shear strength of wall without expansion of wall sectional area and additional weight of total structure. However, the complexity of mechanical behavior of masonry shear wall and the lack of experimental data of masonry wall which was retrofitted by FRPs may cause the problem that engineers hard to determine the retrofitting level. Determining and providing the information for retrofitting effect of FRPs for masonry shear wall, this paper investigate in-plane shear behavior of URM and retrofitted masonry shear walls using two types of different FRP materials. Specimens were designed to idealize the wall of low rise apartment which was built in 1970s Korea with no seismic reinforcements and have 1 aspect ratio. Retrofitting materials were carbon FRP and Hybrid sheet which have different elastic modulus and ultimate strain. Consequently, this study will evaluate the structural capacity of masonry shear wall and retrofitting effect of FRP sheet for in plane shear behavior comparing with evaluation method for reinforced concrete beam which was retrofitted by FRPs.

The Whittier Narrows, California Earthquake of October 1, 1987—Preliminary Evaluation of the Performance of Strengthened Unreinforced Masonry Buildings

1988 ◽  
Vol 4 (1) ◽  
pp. 197-212 ◽  
Author(s):  
T. A. Moore ◽  
J. H. Kobzeff ◽  
J. Diri ◽  
C. Arnold
Keyword(s):  
Los Angeles ◽  
Case Studies ◽  
Unreinforced Masonry ◽  
Preliminary Evaluation ◽  
Masonry Buildings ◽  
Plane Shear ◽  
Hazard Reduction ◽  
Out Of Plane ◽  
Shear Failures ◽  
Bending Failure

This report presents preliminary case studies of the performance of selected unreinforced masonry buildings during the Whittier Narrows Earthquakes. Attention is focused on buildings located in the downtown Los Angeles area which have been rehabilitated to conform with the Los Angeles hazard reduction Ordinance. There was no life loss or major injuries attributed to the response of unreinforced masonry buildings to the earthquakes. However, there was a significant number of both rehabilitated and non-strengthened buildings for which masonry peeled off upper story walls. This was mainly due to separation of the outer whythe of brick, or out-of-plane bending failure, and/or in-plane shear failures of wall piers, particularly at building corners. The falling bricks associated with these failures did present an injury hazard so it is important to investigate economical measures to minimize these hazards in future earthquakes.

scholarly journals SEISMIC RETROFITTING OF REINFORCED CONCRETE SHEAR WALL USING CARBON FIBER REINFORCED POLYMERS (CFRP)

2020 ◽  
Vol 15 (12) ◽  
Author(s):  
Shahzad Khan
Keyword(s):  
Shear Wall ◽  
Seismic Retrofitting ◽  
Fiber Reinforced Polymers ◽  
Carbon Fiber Reinforced Polymers ◽  
Reinforced Polymers ◽  
Reinforced Polymer ◽  
Before And After ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Constant Axial Load

In this paper, the experimental results of a partially retrofitted non-compliant with code concrete shear wall using uni-directional carbon fibre reinforced polymer (CFRP) are introduced. The common deficiencies in the wall were insufficient reinforcement, un-confinement at boundary zone, the lake of in-plane stiffness, and ductility. The adopted retrofitting technique consists of the CFRP strips bonded to both wall face with mesh anchors installed in the wall panel and foundation to avoid debonding. The wall was tested before and after retrofitting under a constant axial load, and the displacement control lateral cyclic load was applied to the head beam level. The retrofitted wall showed satisfactory results in terms of drift and shear strength. The test results include the failure pattern, load-displacement behaviours, and deflected shape.

Retrofitting of School Building Located in Southern Italy

2020 ◽  
pp. 71-94
Author(s):  
Enzo Martinelli ◽  
Ciro Faella ◽  
Emidio Nigro ◽  
Carmine Lima
Keyword(s):  
Wide Class ◽  
Structural Organization ◽  
Seismic Analysis ◽  
Shear Walls ◽  
Shear Wall ◽  
Seismic Assessment ◽  
Seismic Retrofitting ◽  
School Building ◽  
Materials Properties ◽  
Wall System

<p>This paper summarizes the main features of the seismic retrofitting project of a school building located in Montella (AV), Italy. Specifically, it describes the as-built status in terms of structural organization, member detailing, and existing materials properties. Then, it outlines the main assumptions and results obtained from seismic analysis, of both as-built and retrofitted structure. Comments about the construction stage are also reported by describing the main operations put in place with the aim to realize the shear wall system, which is the main retrofitting intervention, and some local strengthening measures consisting in steel plating and jacketing of some underdesigned RC members. Some emphasis is placed on the realization of micro-piles and extra foundations of the aforementioned shear walls. Besides its specific interest, the reported project may be intended as representative of a wide class of seismic assessment and retrofitting projects that have been realized in Italy in the last decade.</p>

Costs and Benefits of Seismic Upgrading of Some Buildings in the Boston Area

1985 ◽  
Vol 1 (4) ◽  
pp. 721-740 ◽  
Author(s):  
M. Elisabeth Paté-Cornell
Keyword(s):  
Reinforced Concrete ◽  
Advisory Committee ◽  
Shear Walls ◽  
Unreinforced Masonry ◽  
Building Codes ◽  
Masonry Buildings ◽  
Existing Buildings ◽  
Costs And Benefits ◽  
Market Effects ◽  
Additional Costs

We examine here the costs and benefits of reinforcing some existing buildings in Boston at the time of remodelling with significant change of use. The buildings of interest are the unreinforced masonry warehouses and the reinforced concrete manufacturing buildings that are remodelled into apartment or office buildings. Given some estimates of the Boston seismicity and of the performance of these buildings in earthquakes with and without additional reinforcement, we evaluate three possible levels of reinforcement that the Masssachusetts Seismic Advisory Committee could recommend as part of the building codes. For the unreinforced masonry buildings, the first upgrading level is the addition of floor and roof diaphragms, and the two subsequent levels involve addition of internal walls and reinforcement of the existing ones. For the reinforced concrete buildings, the first level involves increase of the shear walls' size, and higher upgrading levels involve addition of shear walls and increase of the columns' size. We introduce in our study the market effects of the additional costs. We conclude that only the first levels of reinforcement that we considered could be adopted as regulations, and that higher standards should be left to the choice of the buildings' occupants.

scholarly journals Evaluation of shear and flexural deformations of flexural type shear walls

1984 ◽  
Vol 17 (2) ◽  
pp. 135-144 ◽  
Author(s):  
Hisahiro Hiraishi
Keyword(s):  
Reinforced Concrete ◽  
Evaluation Method ◽  
Shear Walls ◽  
Shear Wall ◽  
Reinforced Concrete Structures ◽  
Test Results ◽  
Structural Components ◽  
Total Deformation ◽  
Restoring Force ◽  
Hysteretic Behaviour

In order to predict the inelastic response of reinforced concrete structures under dynamic earthquake loading, hysteretic behaviour of their structural components must be evaluated appropriately. Though various restoring force models have already been proposed for beams and columns, hysteretic behaviour of flexural type shear walls remains unclear in many respects. In this paper, an evaluation method of distributing the total deformation of a shear wall into the flexural and shear deformation is mentioned and an analytical one of evaluating these deformations is proposed. The comparison of analytical results with test results of shear walls is carried out.

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