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.

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>

scholarly journals Effect of Building Configuration on Overstrength Factor and Ductility Factor

2021 ◽  
Author(s):  
Sagun Kandel ◽  
Rajan Suwal
Keyword(s):  
Residential Buildings ◽  
Pushover Analysis ◽  
Large Earthquake ◽  
Lateral Force ◽  
Reduction Factor ◽  
Base Shear ◽  
Response Reduction Factor ◽  
Overstrength Factor ◽  
Ductility Factor ◽  
High Level

It is important for the structure to be economical and still have a high level of life safety. The lateral force sustained by the structures during a large earthquake would be several times larger than the lateral force for which the structures are designed. This is opposite to the fact that design loads such as gravity in codes are usually higher than the actual anticipated load. It is based on the probability that the occurrence of large earthquakes is quite rare and the capacity of the structure to absorb energy. The co-factors of response reduction factor which is the overstrength factor and ductility factor reduce the design horizontal base shear coefficient. A total of 36 low-rise residential buildings having different storey, bay and bay lengths are selected and analysed in this paper. NBC 105: 2020 is selected for the seismic design of RC buildings while provision provided in FEMA 356:2000 is used to carry out non-linear pushover analysis. The results indicated that between the different structures, the value of overstrength factor and ductility factor has a high deviation.

Application of uniform hazard spectra in seismic design of multistorey buildings

2000 ◽  
Vol 27 (3) ◽  
pp. 563-580 ◽  
Author(s):  
J L Humar ◽  
M A Rahgozar
Keyword(s):  
Seismic Design ◽  
Reduction Factor ◽  
Degree Of Freedom ◽  
Base Shear ◽  
Uniform Hazard Spectra ◽  
Single Degree Of Freedom ◽  
Building Frames ◽  
Higher Mode Effects ◽  
Mode Effects ◽  
Adjustment Factors

The use of uniform hazard spectra for obtaining the seismic design forces is being considered for the next version of the National Building Code of Canada. Such spectra provide the spectral accelerations of a single-degree-of-freedom system for a range of periods but for a uniform level of hazard. One of the issues that need to be resolved before uniform hazard spectra are used in the design of multistorey buildings is the adjustment required in the base shear to account for the higher mode effects present in a multi-degree-of-freedom system. This issue is examined through analytical studies of the response of idealised elastic and inelastic multistorey building frames to ground motions representative of the seismic hazard in the eastern and western regions of Canada. Representative values are obtained for the adjustment factors that must be applied to the design base shear and to the base overturning moment.Key words: seismic design base shear, uniform hazard spectra, higher mode effects, base shear adjustment factor, base overturning moment reduction factor.

scholarly journals Application of Seismic Resisting Systems for Building Construction in Malaysia

2019 ◽  
Vol 8 (2S2) ◽  
pp. 71-75
Keyword(s):  
Structure Type ◽  
Reduction Factor ◽  
Design System ◽  
Seismic Load ◽  
Live Load ◽  
Foundation Soil ◽  
Braced Frame ◽  
Response Reduction Factor ◽  
Load Intensity ◽  
Node Displacement

Over the centuries, there has been a lot of earthquakes occur due to sudden changes in the surface of the earth. This phenomenon has caused property destruction, a large number of deaths and damage to buildings. This situation has become a concern by experts, especially engineers around the world since the damage of the building caused huge losses as well as contributing to the loss of life due to burial and so forth. Therefore, this study is conducted to compare the changes of node displacement that occur in each designed buildings caused by the seismic load applied and to determine the best design system that has the smallest amount of node displacement changes during the quake. In this study, three types of model that consist of base frame, shear wall and braced frame are designed using STAAD Pro Software to obtain their displacement reading. Important data such as seismic parameters and load cases which is Zone factor: 0.24, Response reduction factor: 5, Importance factor: 1.5, Structure type: Concrete, Damping: 0.05, Foundation soil type: Medium, Dead load intensity at all floor levels: 6kN/m2 , Live load for roof: 1.5kN/m2 and Live load for other floors: 3kN/m2 are inserted. The strength of resistance toward seismic load between the three models can be evaluated through the displacement occurs in the nodes in every model.

scholarly journals Assessment of Response Reduction Factor of Flat Slab Structures by Pushover Analysis.

2020 ◽  
Vol 9 (6) ◽  
pp. 157-163
Keyword(s):  
Large Scale ◽  
Seismic Waves ◽  
Smart Cities ◽  
Pushover Analysis ◽  
Elastic Base ◽  
Reduction Factor ◽  
Base Shear ◽  
Flat Slab ◽  
Response Reduction Factor ◽  
Reinforced Concrete Slabs

India is rapidly developing in every aspect now. As a result of which number of smart cities are now arising. while building such smart cities major role is played by infrastructural development. In this infrastructures, speedy and economical constructions are expected to make them more effective. Among such effective construction systems, Flat slab system is the one and is being widely applied on large scale. Flat slabs are thin solid reinforced concrete slabs which are supported directly by columns without beams. Flat slab system is now well adopted for constructions of high rise multi- storied commercial, residential, institutional buildings. They have adventitious constructive, architectural and economical features including easier formwork, speed of construction, spaciousness, etc. The purpose of this project is to study the seismic behavior of Flat Slab Structure for different seismic zones by assessment of Response Reduction Factor using Pushover analysis. Response reduction factor is the factor by which intensity of seismic waves produced during earthquake (maximum elastic base shear) can be reduced to calculate the design base shear. In the project parameters such as base shear, shear and bending stresses and deflection check in flat slab structure are examined by using ETABS Software.

scholarly journals Evaluation of Response Reduction Factor of Existing Masonry Infilled RC-Buildings in Pokhara

2020 ◽  
Vol 1 (1) ◽  
pp. 41-51
Author(s):  
Tekkan Pandit ◽  
Hemchandra Chaulagain
Keyword(s):  
Pushover Analysis ◽  
Structural Response ◽  
Reduction Factor ◽  
Base Shear ◽  
Rc Buildings ◽  
Design Standards ◽  
Natural Period ◽  
Infill Walls ◽  
Response Reduction Factor ◽  
R Value

Most of the structural designer do not consider masonry infill walls during design process due to a lack of modeling guidelines in design standards and are treated as non-structural elements. In fact, the interaction effect between bounding frames and infill masonry is a complicated issue in nonlinearity of structures. The current seismic codes indirectly incorporate the nonlinear response of structure through linear elastic approach by considering the response reduction factor ‘R’ without comprising infill. In this context, this study evaluates the response reduction factor of existing engineered designed RC frame structures that are designed based on Indian standard codes. For this, three existing RC buildings were selected and performed non-linear pushover analysis. The structural response was examined in terms of natural period, base shear, strength, stiffness, ductility and response reduction factor. The results specify that the buildings with infill walls significantly influence on ‘R’ value of structures. Additionally, study shows that the variation of ‘R’ value mainly depends on the percentage of infill inclusion.

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.

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