Seismic behavior of single-storey steel structures with a flexible roof diaphragm

1996 ◽  
Vol 23 (1) ◽  
pp. 49-62 ◽  
Author(s):  
Robert Tremblay ◽  
Siegfried F. Stiemer

The nonlinear response of 36 rectangular single-storey steel buildings subjected to historical earthquake accelerograms is examined. The buildings were designed according to current Canadian practice. The lateral load resisting system of the buildings includes a flexible metal roof deck diaphragm and vertical bracing located along the exterior walls. The results indicate that the fundamental period of the structures, the maximum drift, the forces and deformations in the roof diaphragm, and the ductility demand on the vertical bracings cannot be adequately predicted with existent design provisions. Tentative design guidelines are proposed on the basis of the results obtained in the study. Key words: analysis, design, seismic, dynamic, structures, steel, roof diaphragm.

1991 ◽  
Vol 18 (6) ◽  
pp. 1062-1077 ◽  
Author(s):  
Richard G. Redwood ◽  
Feng Lu ◽  
Gilles Bouchard ◽  
Patrick Paultre

Braced frame structures designed according to the 1990 edition of the National Building Code of Canada and the CSA standard for steel structures (CAN/CSA-S16.1-M89) are analyzed under a number of different earthquake motions. The nonlinear response is studied in the light of the design philosophy, and the validity of a number of design assumptions is examined. The study is limited to a group of eight-storey frames, located either in Victoria, British Columbia, or Montreal, Quebec, all with the same bracing configuration. A 20-storey frame in Montreal is also considered. The results suggest a number of areas in which improved design provisions could be made. Key words: analysis, design, structural engineering, steel, earthquakes, braced frames.


2000 ◽  
Vol 16 (1) ◽  
pp. 179-203
Author(s):  
James O. Malley ◽  
Charles J. Carter ◽  
C. Mark Saunders

One of the important surprises of the Northridge earthquake of January 17, 1994, was the widespread and unanticipated brittle fracture of welded steel beam-to-column connections. Although no casualties or collapses occurred during the Northridge earthquake as a result of these connection failures, and many WSMF buildings were not damaged at all, a wide spectrum of brittle connection damage did occur, ranging from minor cracking to completely severed columns. This paper summarizes two of the most important documents that have been developed in response to the damage suffered to steel moment frame buildings in the Northridge earthquake. The first, FEMA 267, Interim Guidelines: Evaluation, Repair, Modification and Design of Welded Steel Moment Frame Structures, was generated from studies undertaken as part of a project initiated by the U.S. Federal Emergency Management Agency (FEMA) to reduce the earthquake hazards posed by steel moment-resisting frame buildings. The second document addressed in this paper is the 1997 edition of the American Institute of Steel Construction (AISC) Seismic Provisions for Structural Steel Buildings (commonly referred to as the AISC Seismic Provisions) that incorporates the new information generated by the FEMA-sponsored project and other investigations on the seismic performance of steel structures, and has been adopted by reference into the 2000 International Building Code (IBC).


2018 ◽  
Vol 763 ◽  
pp. 1067-1076 ◽  
Author(s):  
Luigi di Sarno ◽  
Fabrizio Paolacci ◽  
Anastasios G. Sextos

Numerous existing steel framed buildings located in earthquake prone regions world-wide were designed without seismic provisions. Slender beam-columns, as well as non-ductile beam-to-column connections have been employed for multi-storey moment-resisting frames (MRFs) built before the 80’s. Thus, widespread damage due to brittle failure has been commonly observed in the past earthquakes for steel MRFs. A recent post-earthquake survey carried out in the aftermath of the 2016-2017 Central Italy seismic swarm has pointed out that steel structures may survive the shaking caused by several main-shocks and strong aftershocks without collapsing. Inevitably, significant lateral deformations are experienced, and, in turn, non-structural components are severely damaged thus inhibiting the use of the steel building structures. The present papers illustrates the outcomes of a recent preliminary numerical study carried out for the case of a steel MRF building located in Amatrice, Central Italy, which experienced a series of ground motion excitations suffering significant damage to the masonry infills without collapsing. A refined numerical model of the sample structure has been developed on the basis of the data collected on site. Given the lack of design drawings, the structure has been re-designed in compliance with the Italian regulations imposed at the time of construction employing the allowable stress method. The earthquake performance of the case study MRF has been then investigated through advanced nonlinear dynamic analyses and its structural performance has been evaluated according to Eurocode 8-Part 3 for existing buildings. The reliability of the codified approaches has been evaluated and possible improvements emphasized.


2017 ◽  
Vol 3 (1) ◽  
pp. 15-34 ◽  
Author(s):  
Pooriya Ayough ◽  
Sara Mohamadi ◽  
Seyed Ali Haj Seiyed Taghia

Most seismic regulations are usually associated with fixed-base structures, assuming that elimination of this phenomenon leads to conservative results and engineers are not obliged to use near-fault earthquakes. This study investigates the effect of soil–structure interaction on the inelastic response of MDOF steel structures by using well known Cone method. In order to achieve this, three dimensional multi-storey steel structures with moment and braced frame are analysed using non-linear time history method under the action of 40 near-fault records. Seismic response parameters, such as base shear, performance of structures, ductility demand and displacement demand ratios of structures subjected to different frequency-contents of near-fault records including pulse type and high-frequency components are investigated. The results elucidate that the flexibility of soil strongly affects the seismic response of steel frames. Soil–structure interaction can increase seismic demands of structures. Also, soil has approximately increasing and mitigating effects on structural responses subjected to the pulse type and high frequency components. A threshold period exists below which can highly change the ductility demand for short period structures subjected to near-fault records.


2018 ◽  
Vol 763 ◽  
pp. 3-10 ◽  
Author(s):  
Gregory A. MacRae ◽  
George Charles Clifton ◽  
Michel Bruneau

Over the past few years, the South Island of New Zealand has been subject to significant sequences of earthquake shaking. In particular, 2010-2011 events affected the city of Christchurch resulting in large scale demolition of buildings. Also, the recent and continuing 11/2016 events caused severe damage in the countryside, in small towns, and moderate damage further afield. This paper describes “low damage construction” methods being used in NZ, and especially in the Christchurch rebuild, to limit the possibility of building demolition in future large seismic events. The buildings used in the Christchurch rebuild are generally supported by structural steel framing. These steel buildings include BRB systems, EBF systems with replaceable active links, rocking systems, base isolation using friction pendulum systems and/or lead-rubber dissipaters, RBS beams, lead extrusion dissipaters, yielding flexural dissipaters, and friction connections. Concerns about a number of currently used systems are discussed.


Author(s):  
Arash Rostami ◽  
Hamid Alielahi ◽  
Abdoreza Sarvghad Moghadam ◽  
Mahmood Hosseini

Development of civil engineering science has introduced tunneling as an important option in reducing the traffic volume of urban environments. Digging tunnels, in every depth, causes changes in the surface ground structure; tunneling in urban areas, especially when has passed through the residential areas has its own particular importance; therefore, having knowledge about tunnels' behavior and effects of diggings is necessary, and in order to prevent unpredictable damages to the structures is one of the requirements of designing. The performance and behavior of underground structures have been studied by many researchers, but the effects of tunneling on earthquake records and its effects on structures above the ground has taken less attention. This study will try to check earthquake record changes and their impact on steel structures located on top part of the tunnels, and has done this issue with digging some circular tunnels. The results indicate that, tunneling alters the earthquake records and also has affections on structural responses.


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