Minimum-weight seismic design of a moment-resisting frame accounting for incremental collapse

2002 ◽  
Vol 13 (1) ◽  
pp. 35-52
Author(s):  
Han-Seon Lee
Keyword(s):  
Seismic Design ◽  
Minimum Weight ◽  
Moment Resisting Frame ◽  
Moment Resisting ◽  
Incremental Collapse

A new demountable seismic-resistant joint to improve industrial building reparability

2017 ◽  
Vol 8 (3) ◽  
pp. 251-262 ◽  
Author(s):  
Margherita Pongiglione ◽  
Chiara Calderini ◽  
George Bradley Guy
Keyword(s):  
Seismic Design ◽  
Single Type ◽  
Industrial Building ◽  
Content Type ◽  
Moment Resisting Frame ◽  
Repair Costs ◽  
Seismic Resistant ◽  
Moment Resisting ◽  
Steel Connection ◽  
Design Calculations

PurposeIn seismic-prone areas, post-event operability is an important issue for steel warehouses. Even if surviving earthquakes with minimal probability of collapse, these structures might suffer so much damage, that their repair costs would be prohibitive. Strategies for limiting the building's damaged zones to specific parts (or “fuses”) can reduce repair costs. However, the replaceable part is limited to a small portion of the structure, whereas the rest cannot be disassembled. This is an issue for structures whose life span depends more likely on economics rather than on structural performances. Therefore, making them easily disassembled would be an advantage not only in seismic areas but also in any industrialized area. The purpose of this paper is to explore the “Design for Disassembly” (DfD) approach to complement seismic design and find a compromise between them. Design/methodology/approachIn this work, one single type of structures was analysed (the moment-resisting frame), focusing on the design of a “disassemblable” seismic-resistant steel connection. The design process involved several iterations until an “optimum” compromise between seismic design and DfD was met. FindingsThis study shows that a compromise between seismic design and DfD is possible. In this case, the compromise was achieved at the expenses of more complex design calculations and a greater number of components than standard connections. However, this would be compensated for by a higher residual value for the entire structure. Originality/valueEventually, it was proved that a metric for assessing DfD steel connections is possible, but structural analyses are needed to validate it.

scholarly journals ANALISIS PERIODA BANGUNAN DINDING GESER DENGAN BASE ISOLATOR AKIBAT GAYA GEMPA

Teras Jurnal ◽  
2018 ◽  
Vol 7 (2) ◽  
pp. 263
Author(s):  
Mul Muliadi Adi ◽  
M. Kabir Kabir Ihsan
Keyword(s):  
Seismic Design ◽  
Time History ◽  
Shear Wall ◽  
Braced Frame ◽  
Moment Resisting Frame ◽  
Rigid Frame ◽  
Base Isolator ◽  
Non Linear ◽  
Moment Resisting ◽  
Performance Based Seismic Design

Bangunan yang hancur oleh gempa dapat dicegah dengan memperkuat struktur bangunan terhadap gaya gempa yang bekerja padanya. Perkuatan bangunan dapat dilakukan dengan memperkaku bangunan dalam arah lateral yaitu <em>moment resisting frame</em> (<em>rigid frame</em>), <em>braced frame</em> dan <em>shear wall</em>. Bangunan dinding geser merupakan salah satu jenis <em>bangunan</em> tahan gempa gedung beton bertulang menggunakan sistem rangka struktur yang dikombinasikan. Kinerja gedung akan bertambah dan menjadi optimal jika pola penempatan <em>dinding geser</em> serta metode analisanya tepat. Sistem lainnya dalam mengurangi kerusakan bangunan akibat gempa dengan <em>performance based seismic design</em> yaitu dengan menggunakan <em>base isolator.</em>, yang memanfaatkan teknik analisa non-linear berbasis komputer untuk menganalisa perilaku inelastis struktur dari berbagai macam intensitas gerakan tanah (<em>gempa</em>), sehingga dapat diketahui kinerjanya pada kondisi kritis. Tujuan penelitian ini dilakukan untuk mengetahui perioda dalam penggunaan <em>base isolator </em>dengan yang tanpa menggunakan <em>base isolator,</em> pada bangunan sistem ganda, lantai 10 tingkat, bentuk beraturan pada bangunan dinding geser. Analisis data yang dilakukan dengan menggunakan bantuan <em>software </em>komputer <em>SAP2000</em>. Pembebanan pada gedung didasarkan pada peraturan bangunan gedung beton bertulang dan analisa dinamik <em>Time History Modal Analysi</em>s struktur dalam Tata Cara Perencanaan Ketahanan Gempa Untuk Struktur Bangunan Gedung Dan Non Gedung (SNI 1726:2012). Dari hasil penelitian ini dapat diketahui bahwa penggunaan <em>base isolator</em> memperbesar perioda alami. Nilai perioda pada dinding geser dan dinding geser <em>base isolator</em> besarnya berturut-turut 0.988 detik dan 2.465 detik. Hal ini menyebabkan gaya gempa yang bekerja menjadi lebih kecil.

scholarly journals The effect of number and position of braced frames on column behavior of the dual steel structural system (MRF and EBF) (With a view on amplified seismic load)

2015 ◽  
Vol 37 ◽  
pp. 277
Author(s):  
Sajjad Mohammadi ◽  
Abd-ol-Reza Sarvghad Moghaddam ◽  
Alireza Faroughi
Keyword(s):  
Seismic Design ◽  
Structural Model ◽  
Seismic Load ◽  
Structural System ◽  
Braced Frames ◽  
Moment Frame ◽  
Moment Capacity ◽  
Moment Resisting Frame ◽  
Moment Resisting

In seismic design of structures, determination of number and position of braced frames, considering the architectural scheme of projects, is usually confronted by obstacles. Due to this fact, in some cases, selecting the best location and number of braced bays has led to mistakes in determination of their adjacent members (columns) design loads. One of the seismic design requirements of lateral resisting system is to control the columns adjacent to braced bays for load combinations of amplified seismic load, which is a function of over-strength factor of the structure. This research aims to present and introduce the best structural model of number and position of braced frames in a structural system, such as steel moment resisting frame and eccentric braces dual system; because in 3rd revision of Iranian 2800 standard of seismic provision, there are statements and criteria provided only for capacity of moment frame, not for braces. Though the amplified seismic load function is controlled in models which columns are connected to braces in 2 directions, and seismic loads are applied in those 2 directions, number of damage hinges (Exceeding CP) is significantly increased in comparison to the models with straggly braces. As the increase in axial force of these columns leads to decrease in their moment capacity (despite controlling the amplified seismic load provision), columns in dual systems that resist flexure, would be damaged and exceed the collapse threshold much sooner than other columns. This important fact is not presented in Iranian or even American codes and provisions.

Seismic performance of reinforced concrete ductile moment-resisting frame buildings located in different seismic regions

1992 ◽  
Vol 19 (4) ◽  
pp. 688-710 ◽  
Author(s):  
T. J. Zhu ◽  
W. K. Tso ◽  
A. C. Heidebrecht
Keyword(s):  
Reinforced Concrete ◽  
Seismic Design ◽  
Ground Motions ◽  
Base Shear ◽  
High Rise ◽  
Moment Resisting Frame ◽  
Short Period ◽  
Frame Buildings ◽  
Moment Resisting ◽  
Seismic Regions

Seismic areas in Canada are classified into three categories for three different combinations of acceleration and velocity seismic zones (Za < Zv, Za = Zv, and Za > Zv), and ground motions in different zonal combination areas are expected to have different frequency characteristics. The National Building Code of Canada specifies different levels of seismic design base shear for short-period buildings located in areas with different zonal combinations. The specification of seismic design base shear for long-period buildings is directly tied to zonal velocity, irrespective of seismic zonal combination. This paper evaluates the seismic performance of both high-rise long-period and low rise short-period reinforced concrete ductile moment-resisting frame buildings located in seismic regions having Za < Zv, Za = Zv, and Za > Zv. Two frame buildings have 10 and 18 storeys were used as structural models for high-rise buildings, while a set of four-storey buildings were used to represent low-rise buildings. All buildings were designed to the current Canadian seismic provisions and concrete material code. Three groups of earthquake records were selected as representative ground motions in the three zonal combination regions. The inelastic responses of the designed buildings to the three groups of ground motions were analyzed statistically. The results indicate that the distribution of inelastic deformations is significantly different for high-rise frame buildings situated in seismic regions with Za < Zv, Za = Zv, and Za > Zv. Inelastic deformation is concentrated in the lower storeys for high-rise buildings located in Za < Zv areas, whereas significant inelastic deformation can develop in the upper storeys for high-rise buildings situated in Za > Zv regions. The use of three different levels of seismic design base shear for short-period structures improves the consistency of ductility demands on low-rise buildings situated in the three different zonal combination regions. Despite the use of appropriate design base shears for different seismic regions, the ductility demands for these low-rise buildings are relatively high. To avoid excessive ductility demands, it is suggested that the seismic strengths for low-rise short-period buildings should not be significantly reduced from their elastic design base shears. Key words: earthquake, ground motion, seismic, design, reinforced concrete, frame buildings, beams, columns, ductility.

scholarly journals FEMA P695 methodology for safety margin evaluation of steel moment resisting frames subjected to near-field and far-field records

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Mahdi Heshmati ◽  
Alireza Khatami ◽  
Hamzeh Shakib
Keyword(s):  
Seismic Design ◽  
Ground Motions ◽  
Near Field ◽  
Safety Margin ◽  
Far Field ◽  
Performance Factors ◽  
Moment Resisting Frame ◽  
Moment Resisting ◽  
Nonlinear Static ◽  
Special Moment Resisting Frame

AbstractThis study presents the impact of near-field and far-field earthquakes on the seismic design of Intermediate Moment Resisting Frame (IMRF) and Special Moment Resisting Frame (SMRF) structures through FEMA (Federal Emergency Management Agency) P695 methodology to highlight the importance of probabilistic collapse as well as seismic performance factors of these structures. The purpose of this study is to investigate the collapse performance of steel intermediate and special moment resisting frame systems as the most common structural systems in urban areas in order to assess the seismic performance factors used for the design using nonlinear static and dynamic analysis methods. In this regard, as the representatives of low-rise to high-rise buildings, archetypes with 5-, 10- and 15- story of intermediate and special moment resisting frames are designed and then the nonlinear models are developed in OpenSees software. Nonlinear static analyses are performed to assess the overstrength and ductility of these systems. The effects of near-field and far-field ground motions on these frames are investigated through incremental dynamic analysis. These analyses are performed with 22 far-field and 20 near-field ground motion records using FEMA P695 methodology. The results show that near-field earthquakes have serious impacts on the collapse probability of structures. The superiority of special moment resisting frame over intermediate moment resisting frame is quantified in terms of safety margin and median collapse capacity under both near-field and far-field earthquakes. Finally, the results indicate that the response modification factors introduced in seismic design code are acceptable for intermediate moment resisting frame and special moment resisting frame under far-field ground motions. However, in the near-field sites while SMRF system meets the requirements of FEMA P695 methodology, the IMRF system does not satisfy these criteria.

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