Retrofitting of School Building Located in Southern Italy

Author(s):  
Enzo Martinelli ◽  
Ciro Faella ◽  
Emidio Nigro ◽  
Carmine Lima

<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>

Shear walls are a structural system which gives solidness or stability to structures from lateral loads like wind, seismic loads. The structural systems are fabricated by reinforced concrete, plywood/timber unreinforced, reinforced masonry at which these systems are subdivided into coupled shear walls, shear wall frames, shear panels and staggered walls. The present paper work was made in the interest of studying and analysis of various research works involved in enhancement of shear walls and their behaviour towards lateral loads. In SAP2000 analysis we found that when we apply lateral force between the stories the amount of compression and tension force between the stories obtained is equal to the manual analysis .In STAAD.PRO, we analyzed the light frame shear wall for seismic analysis. The estimated results for light frame shear wall with one storey, shear wall with two storey and shear wall with three storey shown similar to the results which are obtained by using FEM software like STAAD and SAP2000.


Author(s):  
Gajagantarao Sai Kumar ◽  
Purushotham Rao ◽  
Partheepan Ganesan

Multi-storey buildings tend to get damaged mainly during earthquake. Seismic analysis is a tool for the estimation of structural response in the process of designing earthquake resistant structures and/or retrofitting vulnerable existing structures. The principle purpose of this work is to analyze and design a building with a shear wall and also to find the appropriate position of shear wall that result in maximum resistance towards lateral forces and minimum displacement of the structure. In this study, a G+7 multi-storey building of 15 m ×20 m in plan area has been chosen and modelled using ETABS. The developed model was validated by solving manually and the results were validated in ETABS. Thereafter, 4 different new plans were modelled in ETABS located in the same earthquake zone area. These plans have shear wall concepts are implemented on the building at four different locations. Seismic, vibration and response spectrum analysis were performed on these structures. Salient parameters such as storey stiffness, storey displacement and storey drift were computed using the ETABS model. These were compared with that of the frame having no shear walls. By comparing the results obtained at different shear wall locations, the best plan with the shear wall having minimum lateral storey displacement and maximum stiffness is suggested for this location.


2013 ◽  
Vol 53 (6) ◽  
pp. 913-922
Author(s):  
Ulrich Wirth ◽  
Nuri Shirali ◽  
Vladimír Křístek ◽  
Helmut Kurth

Based on a series of alternating, displacement-controlled load tests on ten one-third scale models, to study the behaviour of the interface of a hybrid shear wall system, it was proved that the concept of hybrid construction in earthquake prone regions is feasible. The hybrid shear-wall system consists of typical reinforced concrete shear walls with composite edge members or flanges. Ten different anchorage bar arrangements were developed and tested to evaluate the column-shearwall interface behaviour under cyclic shear forces acting along the interface between column and wall panel. Finite element models of the test specimens were developed that were capable of capturing the integrated concrete and reinforcing steel behaviour in the wall panels. Special models were  developed to capture the interface behaviour between the edge columns and the shear wall. A comparison between the experimental results and the numerical results shows excellent agreement, and clearly supports the validity of the model developed for predicting the non-linear response of the hybrid wall system under various load conditions.


2020 ◽  
Author(s):  
Ehsan Borbory

One of the types of earthquake-resistant systems is the concrete shear wall system, which has attracted the attention of engineers due to its good performance in past earthquakes. But some architectural constraints force engineers to install openings in shear walls; thus, this will affect the behavior of the shear wall. Many researchers have conducted experimental and finite element studies for assessing the effects of openings in reinforced concrete shear walls. However, there is a lack of comprehensive comparisons between different studies. This paper reviews some most recent experimental and finite element studies available in the literature and presents a review of the main contributions. This literature review reveals that the seismic responses and the stiffness of structures are influenced by the size and location of the openings in the reinforced shear wall.


2015 ◽  
Vol 1120-1121 ◽  
pp. 1516-1519
Author(s):  
Yong Song Shao ◽  
Feng Ru Shao

Due to mechanical performances of brace and steel plate, mechanical properties of semi-rigid joints and its construction and installation, semi-rigid steel frame-braced steel plate shear wall system is proposed. Nonlinear static analysis with parameters (thickness of plate, type of brace, size of brace and the ratio of span to height) changed of a single-span and single-floor semi-rigid steel frame-braced steel plate shear wall system illustrates that braced steel plate shear walls contributes obviously to bearing capacity and lateral rigidity of semi-rigid steel frame. Also, the finite element analysis (by ANSYS) show that semi-rigid steel frame-braced steel plate shear wall system has excellent ductility.


Buildings that rest on sloping ground are different from those that rest on level ground. Buildings located on sloping ground are much more prone to earthquakes because they are, in general, irregular, asymmetrical and tensional. Therefore, the movement of the ground affects them much more. Therefore, there is increased insertion of the shear wall to resist side loading. In this work, the multi-storey building G + 20 is analyzed on slopes of 0o and 24o. For the improvement and analysis of full-filled shear walls, GMT, type L and type C soft soil is used. The structure is analyzed by the response spectrum method and responses such as displacement, ground deviation, period and base slices are evaluated and compared using E-TAB software.


2010 ◽  
Vol 452-453 ◽  
pp. 765-768 ◽  
Author(s):  
B.I. Bae ◽  
B.K. Park ◽  
Hyun Ki Choi ◽  
Chang Sik Choi

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.


CONSTRUCTION ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 93-101
Author(s):  
Saffuan Wan Ahmad ◽  
Muhammad Aimran Amzar Kamarudin ◽  
Wan Aniq Ridhwan Wan Ariffin

On the 5th June 2015, an earthquake hit Ranau, Sabah with a magnitude of 6.0 that caused 18 casualties and several injuries are one of the examples that show Malaysia is not safe from any seismic event. Most of the structure in Malaysia was designed not to include seismic action.  Furthermore, an area that has a high density of population such as in the central region (Klang valley) and several main cities in Malaysia has less available land to build landed housing and uses high-rise apartments as an alternative. High-rise buildings that are normally having problems with soft story mechanisms and plan irregularity which could lead to severe damage when earthquakes happen. This study aims to observe the response of high-rise buildings when under different earthquakes in the presence of shear walls. To achieve this objective two models were modelled and analyzed by using ETABS software, the one with a shear wall and the one with no shear wall. The methods used in this study were the response spectrum method and time-history analysis. In the end, the parameters observed were base shear, story stiffness, story drift, and story displacement. The observations highlighted that the effect of earthquake intensities shows a significant effect. The acquired results indicated that the building with the shear wall is more resistant and strong structures as compared to buildings without shear wall when undergoing seismic analysis.


Author(s):  
Seyed MohammadReza Emrani ◽  
Siamak Epackachi ◽  
Payam Tehrani ◽  
Ali Imanpour

Steel-concrete composite shear wall offers a favourable lateral strength and deformation ductility for seismic applications while significantly shortening the project schedule through eliminating the use of formworks and taking advantage of modular construction methodology. This paper presents a fibre-based modelling technique for simulation of the cyclic nonlinear response of composite walls by taking advantage of existing reinforced concrete and steel plate shear wall models. The improved modelling technique for cyclic analysis of composite walls that benefits from the macro models available for steel and concrete shear walls is introduced. The model is validated using experimental test data from 20 wall specimens. A sensitivity analysis is performed to examine the influence of various geometrical and material properties using the proposed modelling technique. A step-by-step modelling recommendation is finally proposed. The results show that the proposed modelling technique can efficiently be used to reproduce the nonlinear cyclic response of composite walls.


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