scholarly journals Effect of the Bracing System on the Probability of Collapse of Steel Structures under Maximum Credible Earthquake

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Alireza Kianmehr

Simple bracing frames can be divided into two types in terms of concentric or eccentric. Concentric bracing frames are frames that intersect with other structural members at one point in the structure along the bracing members. Otherwise, the braced frame will be eccentric. It is said empirically that due to this type of shaping, eccentric bracing frames exhibit more ductile behavior and concentric bracing frames exhibit more stiff behavior. This behavioral difference caused this study to be numerically computing for five frames, including unique concentric and eccentric bracing frames of 5 and 10 stories and an ordinary 5-story concentric bracing frame. Their tensions and drift ratios should be acceptable for the use of residential buildings. Using the primary two steps of the new PEER probabilistic framework, namely, probabilistic seismic hazard analysis and structural analysis, which leads to the drawing of fragility curves, the probability of collapse is obtained to compare the safety capability of these frames according to their different characteristics against earthquakes. The results show that increasing the ductility or increasing the number of floors or the height of these systems can reduce collapse. Also, according to the results of the probability of collapse obtained in frames with 5-story concentric bracing frames, it can be said that some of the current regulations, which work based on previous approaches of analysis, can lead to unsafe structures with a high probability of collapse.

2017 ◽  
Vol 7 (6) ◽  
pp. 2139-2146 ◽  
Author(s):  
H. Veladi ◽  
H. Najafi

According to most valid Design Codes including the Iranian Seismic Design Code (Standard No. 2800), moment resisting frames in dual systems must have the ability of resisting the 25% of the total lateral load of the dual system independently. This study is conducted to investigate the implementation of this rule for dual steel structures with two types of steel braced frame. Also, its effect on the strength of the structure and the distribution of lateral load between the frames and the bracing system is evaluated. In order to investigate the effect of that rule, structural models with 5, 10 and 15 floors are modeled. Nonlinear static analysis is employed and results are discussed. Following the Standard No. 2008 seems to increase the structure’s lateral resistance and decrease the number of elements entered into the inelastic behavior stage. In general, the structure has a more desirable inelastic behavior.


Abstract. A steel structure is naturally lighter than a comparable concrete construction because of the higher strength and firmness of steel. Nowadays, the growth of steel structures in India is enormous. There are so many advantages in adopting the steel as structural members. Almost all high-rise buildings, warehouses & go-downs are steel structures and even some of the commercial buildings are made of steel. Tension members are the elements that are subjected to direct axial load which tends in the elongation of the structural members. Even today bolted connections play a major role in the connection of hot rolled structural steel members. In this experimental study the behavior of tension members (TM) such as plates, angles & channels have been studied under axial tensile force. There is strong relation between pitch and gauge (with in the specified limit as per IS 800:2007) in determining the rupture failure plane. In this study we intensively tested the behaviour of TM for different fasteners pattern by changing the pitch, gauge, end & edge distance and by adopting the different patterns or arrangements of bolted connection in it.


Author(s):  
Masamichi Ohkubo

To resolve the undesirable effects of reinforced concrete non-structural walls to the earthquake behaviour of structural members, weak points (called "Structural Slits") are intentionally provided at the connection between structural members and non-structural walls. This paper presents an estimation method for the stress developed in the "Structural Slits" which are applied to the non-structural walls of reinforced concrete high-rise residential buildings.


EXTRAPOLASI ◽  
2020 ◽  
Vol 17 (2) ◽  
pp. 35-44
Author(s):  
Nurul Rochmah

AbstractIndonesia is one of the areas where earthquakes often occur, one reason is that Indonesia is located on the border of the oceanic plate, namely the pacific ocean and the continental plate, namely the Eurasian continent. Where in these areas plate shifts often occur which cause frequent earthquakes.In minimizing casualties due to building failure due to earthquakes, one of them is necessary to make a building that has sufficient ductility so that in this study using a steel structure building.In steel structures, to make the structure more resistant to lateral loads, it is necessary to apply bracing. In this study, we try to compare the eccentric and concentric bracing displacement in steel structure buildings.Based on the results obtained from the comparison of these displacements, it is found those displacements due to eccentric bracing is smaller than the concentric bracing  AbstrakIndonesia termasuk daerah yang sering terjadi gempa, salah sebabnya karena wilayah Indonesia terletak di daerah perbatasan lempeng samudera yaitu samudera pasisfik dan lempeng benua yaitu benua Eurasia. Dimana di daerah tersebut sering terjadi pergeseran lempeng yang menyebabkan sering terjadi gempa.Dalam meminimalisir korban akibat kegagalan bangunan akibat gempa salah satunya perlu membuat suatu bangunan yang mempunyai daktilitas yang cukup sehingga dalam penelitian ini memakai gedung struktur baja.Pada Struktur baja untuk lebih membuat struktur bisa tahan terhadap beban lateral maka perlu diberi bresing. Dalam penelitian ini mencoba untuk membandingkan simpangan bresing eksentrik dan konsentrik pada gedung struktur baja.Berdasarkan hasil yang diperoleh dari perbandingan simpangan tersebut, maka diperoleh simpangan akibat bresing eksentrik lebih kecil di banding bresing konsentrik.


2017 ◽  
Vol 33 (1_suppl) ◽  
pp. 415-438 ◽  
Author(s):  
Max Didier ◽  
Salome Baumberger ◽  
Roman Tobler ◽  
Simona Esposito ◽  
Siddhartha Ghosh ◽  
...  

A Rapid Visual Damage Assessment was initiated in the direct aftermath of the 2015 Gorkha earthquake to assess the safety and damage of residential buildings in the areas affected by the earthquake. Over 30,000 paper assessment forms have been subsequently digitized. The collected data set allows comparison of the observed damage to the residential building stock to the damage expected using existing fragility curves. Under certain conditions and respecting certain limitations, the post-earthquake building safety and damage data can be used to update the existing fragility functions for the Nepalese building stock. Recommendations are made for the improvement of post-earthquake building safety assessments in Nepal in order to: (1) make data collection more consistent, (2) increase the accuracy of the collected data, and (3) make more effective use of the collected data after future earthquakes.


1991 ◽  
Vol 18 (5) ◽  
pp. 839-850 ◽  
Author(s):  
R. G. Redwood ◽  
V. S. Channagiri

New provisions of the CSA standard for steel structures (CAN/CSA-S16.1-M89) dealing with detailing of concentrically braced frames for seismic design are described and related to requirements of the National Building Code of Canada. The basis of the new requirements is outlined, and an example eight-storey frame is used to outline a methodology for the design process for a ductile braced frame and to illustrate the impact of the provisions. Key words: design, structural engineering, steel, earthquakes, braced frame, standards.


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