unreinforced masonry buildings

A recent earthquake of M=4.9 occurred on 29 October 2007 in C, ameli, Denizli, which is located in a seismically active region at southwest Anatolia, Turkey. It has caused extensive damages at unreinforced masonry buildings like many other cases observed in Turkey during other previous earthquakes. Most of the damaged structures were non-engineered, seismically deficient, unreinforced masonry buildings. This paper presents a site survey of these damaged buildings. In addition to typical masonry damages, some infrequent, event-specific damages were also observed. Reasons for the relatively wide spread damages considering the magnitude of the event are discussed in the paper

An approximation method for design applications related to sway in RC framed buildings

In this paper, an approximate method is proposed for determining sway of multistory RC buildings subjected to various types of lateral loads. The calculation of both fundamental period and stability index in RC building requires the sway term at each story level. Using approximate method design engineers can estimate sway terms at each story level. The developed analytical expressions are inserted into fundamental period and stability index equations to replace the sway terms, which yields modified equations for fundamental period and stability index without any sway terms. It is fairly easier to employ these equations developed by eliminating all sway terms. Results obtained from the equations are remarkably close to those generated by the related computer program. Consequently, design engineers can reliably use the simple equations to calculate stability index and fundamental period, which enables the determination of these parameters without referring to the complex sway terms. The capability and accuracy of the proposed equations are demonstrated by a numerical example in which computer program results are compared with the proposed methodology

Seismic strengthening of RC structures with exterior shear walls

Abstract.: Vulnerable buildings and their rehabilitation are important problems for earthquake regions. In recent decades the goal of building rehabilitation and strengthening has gained research attention and numerous techniques have been developed to achieve this. However, most of these strengthening techniques disturb the occupants, who must vacate the building during renovation. In this study, a new strengthening alternative for RC structures, namely exterior shear walls, has been experimentally investigated under reversed cyclic loading. Using the proposed technique, it is possible to strengthen structures without disturbing their users or vacating the building during renovation. In this technique, shear walls are installed in parallel to the building's exterior sides. It has been observed that the usage of exterior shear walls considerably improve the capacity and sway stiffness of RC structures. The experimental results have also been compared and found to be in agreement with the numerical solutions. Post attached exterior shear walls behaved as a monolithic member of the structure. Design considerations for the exterior shear wall-strengthened buildings have also been discussed in the paper. © 2011 Indian Academy of Sciences

Seismic strengthening of pin-connected precast concrete structures with external shear walls and diaphragms

Pin-connected precast concrete structures are widely used in some European countries of moderate seismicity. However, this structural system is not earthquake resistant because it does not have enough lateral stiffness or lateral-load resistance. Lack of a rigid diaphragm at the roof level imposes severe forces to connections. It is difficult to strengthen such buildings with conventional strengthening techniques because buildings must be unoccupied before retrofitting, which building owners do not like. To overcome this difficulty, employment of external shear walls and a diaphragm at roof level are proposed in this study. A typical pin-connected precast concrete frame and a strengthened structure with the proposed method were tested under imposed, reversed, cyclic drift of constant rate. The experimental study showed that the proposed method increased lateral stiffness, lateral-load resistance, and seismic energy dissipation and provided a diaphragm effect for the structure

Public Health Rep

19313859PMCnul

A NEW METHOD FOR STRENGTHENING OF PRECAST INDUSTRIAL STRUCTURES

1998 Ceyhan and 1999 Marmara Earthquakes causes extensive damages of the precast industrial structures. This type of structures is important economically. They do not have enough lateral rigidity, lateral load capacity and a rigid diaphragm. Several strengthening techniques have been applied to those type of structures. However, minimization of the disturbance during the strengthening of these structures is an important research issue as considerable economic losses are to be happen while building remains out-of-service. In this study, effectiveness of the strengthening with external shear walls and rigid diaphragm is investigated experimentally. A typical precast concrete frame and a strengthened structure with proposed method are tested under reversed cyclic loads. Experiments showed that proposed method improves lateral stiffness, base shear capacity and provides an efficient diaphragm behavior to the structure

external shear walls and diaphragms

Pin-connected precast concrete structures are widely used in some European countries of moderate seismicity. However, this structural system is not earthquake resistant because it does not have enough lateral stiffness or lateral-load resistance. Lack of a rigid diaphragm at the roof level imposes severe forces to connections.It is difficult to strengthen such buildings with conventional strengthening techniques because buildings must be unoccupied before retrofitting, which building owners do not like. To overcome this difficulty, employment of external shear walls and a diaphragm roof level are proposed in this study.A typical pin-connected precast concrete frame and a strengthened structure with the proposed method were tested under-imposed, reversed, cyclic drift of constant rate. The experimental study showed that the proposed method increased lateral stiffness, lateral-load resistance, and seismic energy dissipation and provided a diaphragm effect for the structure

Investigating benefits from the implementation of environmental management systems in a Greek university

Higher Education Institutions (HEIs) can contribute significantly to the achievement of environmental sustainability through teaching and research activities, and also through improvements in the environmental management of University estates. This article explores the results of implementing Environmental Management Systems (EMSs) in a HEI in Greece. Specifically, the results of two surveys, focusing on students’ perceptions in the University of the Aegean, are presented and analysed. The surveys were conducted prior and after the implementation of an EMS in the University. The survey results demonstrate several positive consequences from the implementation of EMS across the University campus. In particular, there is a positive influence on students’ environmental awareness and behaviour, accompanied by greater preference among them for more participatory environmental management initiatives