Development of Indian standards in EQ resistant design of bridges – past, present and future prospects

2021 ◽  
Author(s):  
Alok Bhowmick ◽  
Harpreet Singh
Keyword(s):  
Seismic Design ◽  
Soil Condition ◽  
Reduction Factor ◽  
Design Parameters ◽  
Seismic Zone ◽  
Ground Acceleration ◽  
Response Reduction Factor ◽  
Local Soil ◽  
Importance Factor ◽  
Indian Railway

<p>Evolution of seismic design provisions in various Indian Standards over the last 50 years have been reviewed in this paper. Seismic provisions of Bureau of Indian Standards (BIS) code (IS 1893), Indian Road Congress (IRC) standard (IRC:6 &amp; IRC:SP:114) and Indian Railway standards (IRS code) are compared. Design parameters for comparison include the seismic zone factor / peak ground acceleration, importance factor, local soil condition, design spectra and response reduction factor.</p>

Efficacy of Importance Factor in Seismic Design of Indian Buildings

2016 ◽  
Vol 857 ◽  
pp. 71-75
Author(s):  
V. Sukumar ◽  
J. Arunachalam ◽  
D.C. Haran Pragalath
Keyword(s):  
Seismic Design ◽  
Reduction Factor ◽  
Seismic Load ◽  
Base Shear ◽  
Public Buildings ◽  
Response Reduction Factor ◽  
Rc Frames ◽  
Time Period ◽  
Importance Factor ◽  
Load Evaluation

At present, seismic load evaluation for design of Indian buildings are carried out using Indian seismic code. In which, building Time period, Response Reduction factor and Importance factor alters design base shear majorly. Currently IS code defines Importance factor differently as “1” for general buildings and “1.5” for public buildings. This factor makes public buildings as heavier sections as it increases design base shear. However there are no evidence that, how this importance factor affects/alters/improves the seismic behavior of buildings. In this present study, four storey RC frames are designed with different importance factors. Pushover analyses are carried out to find its effects on over strength factor and response reduction factor.

Validation of seismic design parameters for wood-frame shearwall systems

2002 ◽  
Vol 29 (3) ◽  
pp. 484-498 ◽  
Author(s):  
Ario Ceccotti ◽  
Erol Karacabeyli
Keyword(s):  
Seismic Design ◽  
Peak Ground Acceleration ◽  
Time History ◽  
Design Parameters ◽  
Ground Acceleration ◽  
Frame Building ◽  
Current Design ◽  
Wood Frame ◽  
Design Earthquake ◽  
Nonlinear Time History

A methodology for assessment of seismic design parameters for a wood-frame shearwall system is developed, consisting of a test program of shearwalls and the application of nonlinear time history analyses to a four-storey wood-frame building that was designed to resist the seismic requirements for Vancouver, British Columbia. Analyses employed 22 selected earthquake accelerograms that were scaled upwards until an ultimate peak ground acceleration (Au) was reached where the shearwall reached a "near-collapse" state. The 22 values of Au were found to be greater than the "design" peak ground acceleration, indicating the adequacy of the current design procedures for the particular shearwalls investigated. The influence of gypsum wallboard on the behaviour of the shearwalls was also evaluated, and a new force modification factor "R" for walls composed of a mixture of wood-based and gypsum panels was proposed. The effect of flexibility of floor diaphragms was considered separately for a symmetric building and was found to have 5-30% reduction on the Au values obtained for the rigid diaphragm case.Key words: seismic design, earthquake loads, timber structures, wood shearwalls.

SEISMIC DESIGN VERIFICATION OF STEEL PRE-ENGINEERED BUILDINGS

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Satish Kumar S. Rajaram ◽  
Nibedita Sahoo
Keyword(s):  
Seismic Design ◽  
Local Buckling ◽  
Element Model ◽  
Reduction Factor ◽  
Response Reduction Factor ◽  
Lateral Capacity ◽  
Post Buckling ◽  
The Moment ◽  
Ductile Behavior ◽  
Strength And Ductility

Steel built-up I sections, composed of plates with high width-to-thickness ratios (slender sections), are commonly used in pre-engineered buildings under the premise that the design is governed by wind. However, in the event of a severe earthquake, the sections are susceptible to local buckling and may exhibit a non-ductile behavior. Therefore it is imperative to check the performance of such structures under the maximum credible earthquake (MCE). As a first step towards this objective, it is necessary to evaluate the post-buckling strength and ductility of such sections. In this study, a Finite element model is developed to analyze the inelastic post-buckling response of semi-compact and slender plates. The information can be used to predict the moment-rotation curves for I-sections with slender webs. A parametric study was carried out on a total of 54 pinned-base PEB frames of varying spans and heights. The elastic seismic demand under severe earthquake was estimated and compared with the design lateral capacity of PEB frames. From the results, it is concluded that even for higher seismic zones, low ductility sections (1.5 to 2) are adequate to survive MCE. Alternatively, if the design is verified for a response reduction factor of 2, then non-ductile sections can also be used.

scholarly journals Risk-adjusted Design Basis Earthquake’s Adequacy for use in Seismic Design Codes

2021 ◽  
Author(s):  
Mohammad Zaman ◽  
Mohammad Reza Ghayamghamian
Keyword(s):  
Seismic Design ◽  
Peak Ground Acceleration ◽  
Design Parameters ◽  
Design Codes ◽  
Acceptance Criteria ◽  
Ground Acceleration ◽  
Seismic Codes ◽  
Residual Drift ◽  
Design Basis ◽  
Made In

Abstract In most buildings’ seismic design codes design basis peak ground acceleration (PGADBE) is provided by employing a uniform-hazard approach. However, a new trend in updating seismic codes is to adopt a risk-informed method to estimate the PGADBE so-called risk-adjusted design basis peak ground acceleration (PGARDBE). An attempt is made here to examine the adequacy of the PGARDBE to fulfill the assumptions made in seismic codes for converting the maximum considered earthquake’s (MCE) intensity to PGADBE. To this end, the performance of regular intermediate steel moment frames (IMF) is assessed in terms of collapse margin (CMR) and residual drift ratios in the event of MCE and design basis earthquake (DBE), respectively. The PGARDBEs are computed for Karaj County, Iran. A set of 96 index archetypes of regular IMF are designed considering four design parameters, which include the number of stories (2, 3, 6, 9, 12, and 15), span lengths (4 and 8 meters), occupancies (residential and commercial), and seismic demands (0.15, 0.25, 0.35 and 0.45g). The PGADBE prescribed by Standard No. 2800 for Karaj neither meets the assumed acceptance criteria nor stands on the safe side. Meanwhile, PGARDBE fulfills the acceptance criteria but does not necessarily satisfy the implicit assumption made in codes that the code-conforming buildings have at least a CMR of 1.5 if the MCE occurs. This emphasizes that the PGARDBE should not be used without examining the CMR fulfillment. The results recommend that a lower limit need to be set on PGARDBEs, which is found to be 0.35g for Karaj. Outcomes also reveal that the code-conforming buildings designed with the proposed PGARDBE can fulfill both repairability and life safety performances at the DBE and MCE, respectively. These buildings also have a high chance to be even considered as repairable ones at the seismic demand of MCE. Furthermore, regardless of the employed method for estimating PGADBE, various relationships between design parameters with different performance indicators such as CMR, residual drift ratio, ductility demand, imposed drift ratio, and building’s normalized weight are presented. These relationships can be used to evaluate the buildings’ safety factor against collapse and repairability, justification of using IMF in regions with high seismicity, level of structural and nonstructural damage as well as the economic consequence of changes in PGADBE. The presented relationships provide a multi-criteria decision-making tool to decide on the optimum PGADBE leading to an affordable alternative and tolerable damage.

scholarly journals General Comparison of Seismic Design between the Chinese Code and the European code

2021 ◽  
Vol 276 ◽  
pp. 01031
Author(s):  
Ding Zhiquan ◽  
Wang Zhizhao ◽  
Li Bo
Keyword(s):  
Seismic Design ◽  
Response Spectrum ◽  
Seismic Action ◽  
Seismic Zone ◽  
Design Concepts ◽  
Importance Factor ◽  
European Code ◽  
Precautionary Measures ◽  
Chinese Standard ◽  
Type Classification

To promote overseas projects, it is necessary for designers to understand and distinguish the similarities and differences between the Chinese standard GB50011(Edition 2016) and the European standard EN1998. By referring to relevant papers, comparing the ground types, response spectrum, structural importance factors, seismic precaution level and seismic zoning between the GB50011(Edition 2016) and EN1998, it can be concluded that the overall seismic design concepts in the Chinese and European codes are similar but there are some small differences in ground type classification, impact of ground type on seismic action, response spectrum, importance factor, seismic precautionary criterion, seismic precautionary measures, and seismic zone.

Evaluation of floor acceleration demands from the 2017 Mexico City code seismic provisions using a continuous elastic model and records of instrumented buildings

2020 ◽  
Vol 36 (2_suppl) ◽  
pp. 213-237
Author(s):  
Miguel A Jaimes ◽  
Adrián D García-Soto
Keyword(s):  
Mexico City ◽  
Seismic Design ◽  
Soft Soil ◽  
Response Spectra ◽  
Elastic Model ◽  
Ground Acceleration ◽  
Nonstructural Components ◽  
Floor Response Spectra ◽  
Instrumented Buildings ◽  
Floor Acceleration

This study presents an evaluation of floor acceleration demands for the design of rigid and flexible acceleration-sensitive nonstructural components in buildings, calculated using the most recent Mexico City seismic design provisions, released in 2017. This evaluation includes two approaches: (1) a simplified continuous elastic model and (2) using recordings from 10 instrumented buildings located in Mexico City. The study found that peak floor elastic acceleration demands imposed on rigid nonstructural components into buildings situated in Mexico City might reach values of 4.8 and 6.4 times the peak ground acceleration at rock and soft sites, respectively. The peak elastic acceleration demands imposed on flexible nonstructural components in all floors, estimated using floor response spectra, might be four times larger than the maximum acceleration of the floor at the point of support of the component for buildings located in rock and soft soil. Comparison of results from the two approaches with the current seismic design provisions revealed that the peak acceleration demands and floor response spectra computed with the current 2017 Mexico City seismic design provisions are, in general, adequate.

scholarly journals Seismic Hazard Assessment for the Tianshui Urban Area, Gansu Province, China

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Zhenming Wang ◽  
David T. Butler ◽  
Edward W. Woolery ◽  
Lanmin Wang
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Seismic Design ◽  
Hazard Analysis ◽  
Seismic Hazard Assessment ◽  
Gansu Province ◽  
Mitigation Measures ◽  
Peak Ground Velocity ◽  
Ground Acceleration ◽  
Acceleration Time Histories

A scenario seismic hazard analysis was performed for the city of Tianshui. The scenario hazard analysis utilized the best available geologic and seismological information as well as composite source model (i.e., ground motion simulation) to derive ground motion hazards in terms of acceleration time histories, peak values (e.g., peak ground acceleration and peak ground velocity), and response spectra. This study confirms that Tianshui is facing significant seismic hazard, and certain mitigation measures, such as better seismic design for buildings and other structures, should be developed and implemented. This study shows that PGA of 0.3 g (equivalent to Chinese intensity VIII) should be considered for seismic design of general building and PGA of 0.4 g (equivalent to Chinese intensity IX) for seismic design of critical facility in Tianshui.

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