scholarly journals Dynamic seismic analysis of bridge using response spectrum and time history method

2021 ◽  
Author(s):  
Marame Brinissat ◽  
Rajmund Kuti ◽  
Zouhir Louhibi
Keyword(s):  
Seismic Analysis ◽  
Response Spectrum ◽  
Time History ◽  
Bending Moment ◽  
Highway Bridge ◽  
Structural Elements ◽  
Base Shear ◽  
Shear Forces ◽  
Nonlinear Analyses ◽  
Ground Motion Records

Dynamic analysis is very important to better understand the performance of structural elements of a bridge. For this purpose, a seismic analysis of an Algerian highway bridge designed with the new Algerian seismic bridge regulation (RPOA -2008) was carried out using linear and nonlinear analyses. Therefore, response spectrum, time history analyses were performed to evaluate the seismic responses of the designed bridge. The performance of the designed bridge is assessed using 10 ground motion records. The proposed methodology allows an efficient comparison of the seismic response of the bridge in terms of base shear forces, bending moment and displacements. Finally, the paper concludes with a discussion of the specific outcomes.

scholarly journals Review on Seismic Analysis of Multistoried Building in Hilly Region

2021 ◽  
Vol 9 (12) ◽  
pp. 73-79
Author(s):  
Harsh Joshi
Keyword(s):  
Seismic Analysis ◽  
Response Spectrum ◽  
Center Of Mass ◽  
Time History ◽  
Lateral Loads ◽  
Base Shear ◽  
Building Frames ◽  
Building Frame ◽  
History Analysis ◽  
Hilly Region

Abstract: Due to sloping land and high seismically active zones, designing and construction of multistory buildings in hilly regions is always a challenge for structural engineers. This review paper focuses to establish a review study on the Possible Types of building frame configuration in the hilly region and he behavior of Such building frames under seismic loading conditions, and (3) The recent research and developments to make such frames less vulnerable to earthquakes. This paper concludes that the dynamics characteristics of such buildings are significantly different in both horizontal and vertical directions, resulting in the center of mass and center of stiffness having eccentricity at point of action and not vertically aligned for different floors. When such frames are subjected to lateral loads, due to eccentricity it generates torsion in the frame. Most of the studies agree that the buildings resting on slanting ground have higher displacement and base shear compared to buildings resting on plain ground and the shorter column attracts more forces and undergoes damage when subjected to earthquake. Keywords: Building frame configuration, Seismic behavior, Dynamic characteristics, Response spectrum analysis, time history analysis.

Effects of column stiffness irregularity on the seismic response of bridges in the longitudinal direction

2013 ◽  
Vol 40 (8) ◽  
pp. 815-825 ◽  
Author(s):  
Payam Tehrani ◽  
Denis Mitchell
Keyword(s):  
Seismic Response ◽  
Response Spectrum ◽  
Time History ◽  
Longitudinal Direction ◽  
Elastic Response ◽  
Highway Bridge ◽  
Stiffness Ratio ◽  
Design Code ◽  
Nonlinear Analyses ◽  
Inelastic Analysis

The longitudinal seismic responses of 4-span continuous bridges designed based on the 2006 Canadian Highway Bridge Design Code were studied using elastic response spectrum and inelastic time-history analyses. Several boundary conditions including unrestrained horizontal movements at the abutments and different abutment stiffnesses were considered in the nonlinear analyses. The seismic response of more than 2600 bridges were studied to determine the effects of different design and modelling parameters including the effects of different column heights, column diameters, and superstructure mass as well as different abutment stiffnesses. The bridges were designed using two different force modification factors of 3 and 5. The effects of column stiffness ratios on the elastic and inelastic analysis results, maximum ductility demands, concentration of ductility demands, and demand to capacity ratios were investigated. The results indicate that the seismic response and maximum ductility demands in the longitudinal direction are influenced by important parameters such as the total stiffness of the substructure, the column stiffness ratio, and the aspect ratio of the columns.

scholarly journals A sectionalized-dual-band method for the selection of ground motion record sets

2021 ◽  
Vol 9 (3A) ◽  
Author(s):  
Hongmei Hou ◽  
Keyword(s):  
Dynamic Analysis ◽  
Ground Motion ◽  
Seismic Design ◽  
Response Spectrum ◽  
Time History ◽  
Spectral Shape ◽  
Dual Band ◽  
Base Shear ◽  
Period Range ◽  
Ground Motion Records

It is of great importance to select appropriate ground motion records for time-history dynamic analysis of structures. The consistency between record response spectral shape and seismic design response spectral shape is the basic principle for records selection. A sectionalized-dual-band (SDB) method considering influence of higher modes was proposed to select ground motion records according to the seismic fortification intensity requirements and the site characteristic. Furthermore, the newly proposed method has been employed to construct record sets within the whole response spectrum period. As compared with other traditional methods, the records obtained from the SDB method are more effective in predicting base shear derived from time-history dynamic analysis. When the period of a structure is determined, the records in the matched period range of the records set can be directly used to conduct time-history dynamic analysis. This method can avoid tedious work for reselecting ground motion records for different structures in the same seismic design intensity and site conditions.

scholarly journals Seismic Analysis of L-Shape Multi-Storey RCC Building with X-Bracing in Different Effective Location and Pattern

2021 ◽  
Vol 9 (8) ◽  
pp. 1150-1170
Author(s):  
Mr. Suryakant Pandey
Keyword(s):  
Large Scale ◽  
Seismic Analysis ◽  
Response Spectrum ◽  
Bending Moment ◽  
Engineering Industry ◽  
Frame Structure ◽  
Base Shear ◽  
High Rise ◽  
The Face ◽  
Seismic Forces

Abstract: In this day and age of urbanization, there is a strong need for a large-scale high-rise apartment building in every city but high-rise construction systems are extremely difficult to construct in any seismic region due to the intense and disruptive nature of seismic forces. Seismic forces have the highest risk of causing the most harm to high-rise buildings. To meet this need, the Civil Engineering industry is constantly developing new groundbreaking techniques. To solve this problem RCC or steel bracings are provided in high-rise buildings which help to the low down the effect of seismic and wind forces. The main objective of this paper is to locate an effective position and pattern of the RCC X-bracing system in the L- shape multi-storey building which is subjected to seismic forces. According to a previous reference paper, X-bracing produces better results than other bracing systems. Analysis the seven types of frame models are taken – (1) Normal L-shape building without bracing, (2) Xbracing are provided at the face of L-shape building, (3) X-bracing are provided alternative pattern at the face of L-shape building from bottom to top floor, (4) X- bracing are provided zig-zag pattern at the face of L-shape building, (5) X-bracing are provided at the corner of L-shape building, (6) X-bracing are provided alternative pattern at the corner of L-shape building from bottom to the top floor, (7) X-bracing are provided zig-zag pattern at the corner of L-shape building. Developed and evaluated by response spectrum analysis method (Linear dynamic analysis) as per IS 1893-2000 using STAAD PRO V8i. In the present work G+12 storey, the L-shape frame structure is analyzed by using X-bracing. It is analyzed and the results of the Following Parameters are taken - (1) Peak storey shear, (2) Base shear, (3) Nodal displacement, (4) Maximum bending moment, (5) Total quantity of steel in the whole structure, (6) Total volume of concrete in the whole structure are evaluated and compared. Keywords: RCC Bracing, Seismic Behavior, Seismic Analysis, Peak Storey Shear, Base shear, Nodal Displacements, Maximum Bending Moment, The Total Quantity of Steel, The Total Volume of Concrete

scholarly journals Parametric Study of P-Delta Effect on Irregular RC Structure with Structural Systems Having Different Density of Shear Walls

2021 ◽  
pp. 492-503
Author(s):  
Yash Patel ◽  
Mr Jigar Zala ◽  
Prof. Deepak R. Tarachandani
Keyword(s):  
Parametric Study ◽  
Dynamic Instability ◽  
Response Spectrum ◽  
Drift Time ◽  
Time History ◽  
Bending Moment ◽  
Shear Walls ◽  
Structural Systems ◽  
Base Shear ◽  
History Analysis

P-Delta analysis affect the seismic responses of structures. When the structure responds elastically, its importance can be insignificant, but it is relevant when the structure responds to an inelastic set. The P-∆ effect normally raises the structural displacement response. Dynamic instability can also occur when the system is exposed to extreme earthquake motions. Plan irregularities can lead to substantial eccentricity between the centre of mass and the centre of rigidity in the RC framed structure, which can lead to a negative lateral and torsional response. Irregular structures require more careful structural evaluation to reach a suitable behaviour during an earthquake. In this research, a parametric study will be conducted on G+29 RC framed buildings having plan irregularity with consideration of the P-delta effect. Time history analysis, response spectrum analysis and static co-efficient method will be conducted to evaluate results of different structural systems and study the parameters like Displacement, Storey drift, Time period, Axial force, Base Shear, Bending Moment, etc with the help of structural analysis software ETABs.

Simplified approach for the seismic analysis of precast girder bridges with gap

2021 ◽  
Author(s):  
E. F. Ayoub ◽  
M. Youakim ◽  
P. Nady
Keyword(s):  
Seismic Analysis ◽  
Linear Time ◽  
Response Spectrum ◽  
Time History ◽  
Relative Displacement ◽  
Seismic Effect ◽  
Base Shear ◽  
Simplified Approach ◽  
Elastomeric Bearing ◽  
Girder Bridges

<p>Precast girder bridges are very attractive structural systems to bridge engineers due to their construction rapidity. In their deck arrangement a gap is introduced between the precast girders and the inverted pier cross head. Under longitudinal seismic effect the gap can be closed and the superstructure movement will be locked by the web of the pier cross-head. Usually a rigorous and sensitive non-linear time history analysis will be required for this type of structures. In this paper, a simplified approach will be introduced to estimate the base shear force transmitted to the bridge substructure under seismic loading. In the present approach the modelling of the elastomeric bearing element stiffness is modified in such a way that under earthquake loading the relative displacement between top level and bottom level of bearing equals to the gap value. The seismic analysis with slight, moderate and sharp earthquake accelerations is performed based on the response spectrum analysis as presented by AASHTO LRFD.</p>

The Behaviour of High-Rise Building with or without Shear Wall under Different Earthquakes

CONSTRUCTION ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 93-101
Author(s):  
Saffuan Wan Ahmad ◽  
Muhammad Aimran Amzar Kamarudin ◽  
Wan Aniq Ridhwan Wan Ariffin
Keyword(s):  
Seismic Analysis ◽  
Response Spectrum ◽  
Time History ◽  
Shear Walls ◽  
Shear Wall ◽  
Seismic Action ◽  
Base Shear ◽  
Soft Story ◽  
High Rise ◽  
The One

On the 5th June 2015, an earthquake hit Ranau, Sabah with a magnitude of 6.0 that caused 18 casualties and several injuries are one of the examples that show Malaysia is not safe from any seismic event. Most of the structure in Malaysia was designed not to include seismic action.  Furthermore, an area that has a high density of population such as in the central region (Klang valley) and several main cities in Malaysia has less available land to build landed housing and uses high-rise apartments as an alternative. High-rise buildings that are normally having problems with soft story mechanisms and plan irregularity which could lead to severe damage when earthquakes happen. This study aims to observe the response of high-rise buildings when under different earthquakes in the presence of shear walls. To achieve this objective two models were modelled and analyzed by using ETABS software, the one with a shear wall and the one with no shear wall. The methods used in this study were the response spectrum method and time-history analysis. In the end, the parameters observed were base shear, story stiffness, story drift, and story displacement. The observations highlighted that the effect of earthquake intensities shows a significant effect. The acquired results indicated that the building with the shear wall is more resistant and strong structures as compared to buildings without shear wall when undergoing seismic analysis.

Measured natural periods of concrete shear wall buildings: insights for the design of Canadian buildings

2012 ◽  
Vol 39 (8) ◽  
pp. 867-877 ◽  
Author(s):  
Damien Gilles ◽  
Ghyslaine McClure
Keyword(s):  
Seismic Analysis ◽  
Dynamic Properties ◽  
Response Spectrum ◽  
Shear Wall ◽  
Mode Shapes ◽  
Design Stage ◽  
Base Shear ◽  
Period Equation ◽  
Input Load ◽  
Structural Engineers

Structural engineers routinely use rational dynamic analysis methods for the seismic analysis of buildings. In linear analysis based on modal superposition or response spectrum approaches, the overall response of a structure (for instance, base shear or inter-storey drift) is obtained by combining the responses in several vibration modes. These modal responses depend on the input load, but also on the dynamic characteristics of the building, such as its natural periods, mode shapes, and damping. At the design stage, engineers can only predict the natural periods using eigenvalue analysis of structural models or empirical equations provided in building codes. However, once a building is constructed, it is possible to measure more precisely its dynamic properties using a variety of in situ dynamic tests. In this paper, we use ambient motions recorded in 27 reinforced concrete shear wall (RCSW) buildings in Montréal to examine how various empirical models to predict the natural periods of RCSW buildings compare to the periods measured in actual buildings under ambient loading conditions. We show that a model in which the fundamental period of RCSW buildings varies linearly with building height would be a significant improvement over the period equation proposed in the 2010 National Building Code of Canada. Models to predict the natural periods of the first two torsion modes and second sway modes are also presented, along with their uncertainty.

scholarly journals Implementation of the structural performance factor (Sp) within a displacement-based design framework

2018 ◽  
Vol 51 (3) ◽  
pp. 159-165 ◽  
Author(s):  
Dion Marriott
Keyword(s):  
Response Spectrum ◽  
Time History ◽  
Structural Performance ◽  
Integration Time ◽  
Design Framework ◽  
Base Shear ◽  
Structural Behaviour ◽  
Performance Factor ◽  
Design Response Spectrum ◽  
Displacement Based

This paper discusses the application of the Structural Performance factor (SP) within a Direct Displacement-Based Design framework (Direct-DBD). As stated within the New Zealand loadings standard, NZS1170.5:2004 [1], the SP factor is a base shear multiplier (reduction factor) for ductile structures, i.e. as the design ductility increases, the SP factor reduces. The SP factor is intended to acknowledge the better-than-expected structural behaviour of ductile systems (both strength, and ductility capacity) by accounting for attributes of response that designers are unable to reliably estimate. The SP factor also recognizes the less dependable seismic performance of non-ductile structures, by permitting less of a reduction (a larger SP factor) for non-ductile structures. Within a traditional force-based design framework the SP factor can be applied to either the design response spectrum (a seismic hazard/demand multiplier), or as a base shear multiplier at the end of design (structural capacity multiplier) – either of these two approaches will yield an identical design in terms of the required design base shear and computed ULS displacement/drift demands. However, these two approaches yield very different outcomes within a Direct-DBD framework – in particular, if SP is applied to the seismic demand, the design base shear is effectively multiplied by (SP)2 (i.e. a two-fold reduction). This paper presents a “DBD-corrected” SP factor to be applied to the design response spectrum in Direct-DBD in order to achieve the intent of the SP factor as it applies to force-based design. The proposed DBD-corrected SP factor is attractive in that it is identical to the SP relationship applied to the elastic site hazard spectrum C(T) for numerical integration time history method of analysis within NZS 1170.5:2004 [1], SP,DDBD = (1+SP)/2.

scholarly journals A simplified method for seismic analysis of rooftop telecommunication towers

2007 ◽  
Vol 34 (10) ◽  
pp. 1352-1363
Author(s):  
Rola Assi ◽  
Ghyslaine McClure
Keyword(s):  
Seismic Analysis ◽  
Seismic Excitation ◽  
Base Shear ◽  
Shear Forces ◽  
Modal Superposition ◽  
Dynamic Analyses ◽  
Simplified Method ◽  
Excitation Dynamic ◽  
Telecommunication Towers ◽  
Definition Of

A simplified method is presented in this paper for the estimation of forces at the base of telecommunication towers mounted on building rooftops due to seismic excitation. Although some codes and standards propose simplified methods for the evaluation of base shear forces for towers founded on ground, no method yet exists for the evaluation of overturning moments. The proposed simplified method is based on numerical simulations using truncated modal superposition, which is widely used for seismic analysis of linear structures. The method requires the prediction of input seismic acceleration at the building–tower interface, the definition of an acceleration profile along the building-mounted tower, and the determination or evaluation of the mass distribution of the tower along its height. The method was developed on the basis of detailed dynamic analyses of three existing towers assumed to be mounted separately on three buildings. It was found that the method yields conservative results, especially for the overturning moments.Key words: self-supporting towers, earthquake, horizontal excitation, dynamic analysis, acceleration, modal superposition.

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