scholarly journals Seismic and Time History Performance of RCC Framed Buildings with and without Passive Energy Dissipators

Base isolation is an effective way to protect large structures from earthquake damage. It is a costly approach, as the entire structure must be supported on elastomeric or sliding bearings. Viscous dampers distributed throughout an otherwise conventional structure can achieve the same result at a significantly lower cost. Dampers are used to resist lateral forces coming on the structure. Dampers are the energy dissipating devices which also resist displacement of Reinforced Concrete (RC) buildings during an earthquake. These dampers help the structure to reduce buckling of columns thereby increasing the stiffness of the structure. During earthquakes, multi-storeyed buildings get damaged and as a result, large deformation occurs. Dampers reduce vibration and deformation of structural elements during an earthquake. Retrofitting buildings with fluid viscous dampers (FVDs) can improve Interstorey drifts and floor accelerations. In the present study, an RC framed building is modelled and analysed under Southern Sumatra and Chile earthquakes to evaluate the performance of the structure and its elements with and without energy dissipators. For the study, a model (G+19) with and without energy dissipators is modelled in ETABS. The seismic force is applied based on the time history data of the models pertaining to Southern Sumatra and Chile Earthquake. Response Spectrum analysis has been carried out to find the lateral displacements, storey shear and Base shear for the model with and without dampers. The lateral displacement, storey drift, storey shear and Base shear are found to less for the model with Linear FVDs when compared to the model with Non-Linear FVDs and without FVDs.

2008 ◽  
Vol 385-387 ◽  
pp. 229-232
Author(s):  
Jorge A. Avila ◽  
Eduardo Martínez

Based on a ductile frames 15 level building, a non-linear analysis with increased monotonically lateral loads (Push-Over) was made in order to determine its collapse and its principal responses were compared against the elastic and inelastic time-history seismic responses determined with the SCT-EW-85 record. The seismic-resistance design and faced to gravitational loads was made according to the Complementary Technical Norms of Concrete Structures Design (NTC-Concrete) and the NTC-Seismic of the Mexico City Code (RDF-04), satisfying the limit service states (relative lateral displacement between story height maximum relations, story drifts ≤ 0.012) and failure (seismic behavior factor, Q= 3). The compressible (soft) seismic zone IIIb and the office use type (group B) were considered. The non-linear responses were determined with nominal and over-resistance effects. The comparison were made with base shear force–roof lateral displacement relations, global distribution of plastic hinges, failure mechanics tendency, lateral displacements and story drift and its distribution along the height of the building, local and global ductility demands, etc. For the non-linear static analysis with increased monotonically lateral loads, it was important to select the type of lateral forces distribution.


2020 ◽  
Vol 9 (1) ◽  
pp. 1986-1990

The structural response of any structure is the result of various dynamic phenomenon which lead to vibrations or shaking of the structure , depending on the duration of the ground motion, its frequency and time period. In the present work, dynamic analysis of a typical steel silo is done by using linear Time History Analysis and Response Spectrum method for earthquake Zone V as per Indian code. Two analyses are carried out namely, Time History Analysis (THA) and Response Spectrum Analysis (RSA) using STAAD.ProV8i software. The Load combinations are worked out as per IS-1893-2002. The results in terms of Fundamental natural period, Design Base shear, Lateral Displacements, are compared for the two different silo models considered in the present study.


2017 ◽  
Vol 3 (7) ◽  
pp. 526-536 ◽  
Author(s):  
Hamid Reza Ashrafi ◽  
Mozafar Shokri Rad ◽  
Yahya Adineh Far ◽  
Peyman Beiranvand ◽  
Soroush Dadgar

Current study is sought to study the effect of linear and nonlinear liquid viscous dampers on steel frames having dual systems of bending frame and divergent bracing. These frames were first designed according to regulations of Iran’s 2800 standard and tenth chapter of national regulations of construction (planning and performing steel construction) through equivalent static method then frames were modelled again in non-linear analysis software and time history non-linear analyses were done on them with installing viscous dampers on these frames using recorded near and far faults. In this study the effect of viscous dampers will be investigated on seismic behaviour of mentioned frames and results will be proposed in form of maximum graphs of relative displacements, stories lateral displacements, base shear maximum, waste energy graphs and dampers’ force-displacements. All non-linear analyses have been done in PERFORM-3D software.


2019 ◽  
Vol 19 (03) ◽  
pp. 1950020 ◽  
Author(s):  
Manisha V. Waghmare ◽  
Suhasini N. Madhekar ◽  
Vasant A. Matsagar

The effectiveness of the semi-active control strategies using fluid viscous dampers (SAFVDs) for seismic mitigation of reinforced concrete (RC) elevated liquid storage tanks is investigated. Three control algorithms are employed for regulating the damping coefficient of the SAFVDs: (1) Passive-OFF, (2) Passive-ON, and (3) Clipped Optimal Control (COC). The uncontrolled response of the tank is compared with those installed with SAFVD of different control algorithms. Focus is also placed on various positions of the dampers, viz., dampers installed at alternate levels (Configurations I, II, IV, and V) and at all levels (Configurations III and VI) of the staging. A discrete two-mass model for the liquid and multi-degree-of-freedom system for the staging, installed with the dampers, is developed for the RC elevated liquid storage tanks. The response of the broad and slender tanks is studied, for which the ratios of the height of the liquid to the radius of the container are 0.5 and 2.0, respectively. The time-history response of the elevated tank is evaluated for eight different earthquake ground motions, including near- and far-field earthquakes. A MATLAB code was developed to solve the coupled differential equations of motion of the system using the state-space approach. Key parameters, viz., convective displacement, rigid mass displacement, base shear, overturning moment, and damper force, are evaluated. The results show that all the control systems considered herein are beneficial in reducing the seismic responses. The frequency response function for the uncontrolled and semi-actively controlled liquid storage tank in frequency domain exhibits significant response reduction, highlighting the effectiveness of the SAFVDs. The structural response is effectively controlled using the SAFVDs with Passive-OFF (valve closed) and COC algorithms. The COC algorithm employed in this study is a promising candidate for the seismic mitigation of RC elevated liquid storage tanks using the semi-active control.


2021 ◽  
Vol 1197 (1) ◽  
pp. 012046
Author(s):  
Lingala Ajay ◽  
M. Anil Kumar

Abstract Damping plays a major role in design of structures resistant to earthquakes. The damping reduces the effective of the structure when they are assigned to lateral loads by energy dissipation. The number of dampers is available and in use today. Most of the dampers usually isolate the super structure from the substructure, dividing them in order to hamper the flow of vibrations into the superstructure. This classification is termed as base isolation techniques. While, the rest of the damping techniques, dissipates the oncoming vibrations on the superstructure itself and minimizes the damage to the superstructure. In this present study, Fluid Viscous Dampers (FVD) are used extensively over types of dampers. The structure endures two load types, the vertical loads and the sidewise loads, and conveys to the foundation. In order to have earthquake resistant structures, FVD have been used. In the present study, Dissymmetric Buildings are analyzed with and without Fluid Viscous Dampers. The software ETABS 2016 was used. Using Time history analysis in ETABS software, the RC building is considered and the structure is evaluated and connect with and without FVD.


Author(s):  
Muhammad Ibnu Syamsi ◽  
◽  
Taufiq Ilham Maulana ◽  
Hararya Widyantama ◽  
Muhammad Rezki Ian ◽  
...  

The Aceh earthquake suffering Indonesia in 2004, and some big ground motions afterward led the earthquake-resistant building standard provisions to be updated. The rise of ground motions increases the lateral forces, so reevaluating existing buildings is needed, especially for Irregular buildings, which are more vulnerable than the regular ones. This study investigates the increase of earthquake loads and the building response in the high seismicity region due to the updated Indonesian code from SNI 1726:2002 to SNI 1726:2012. Building A in DI Yogyakarta with vertical irregularity on a certain floor is chosen as the object to be studied. There are two types of seismic loads to be simulated, response spectrum and time history analysis. The building is simulated using the numerical program, and four ground motion histories are selected for the dynamic exiting forces. The analysis result shows an increase in the story force either in the response spectrum or the time history. By taking the building's top floor as the reference point, the increase in lateral displacement is also detected in both response spectrum and time history analysis. From the interstory drift ratio examinations, it is also found that there is a weak point located on the setback part that is not identified just by observing the total displacement. This paper compiles the comparison of two versions of the Indonesian seismic code, two types of seismic force, and two points of view in analyzing the building response. Furthermore, the result presented in this paper also beneficial for mitigating the building.


Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 73
Author(s):  
Osman Hansu ◽  
Esra Mete Güneyisi

This study addresses an alternative use of viscous dampers (VDs) associated with buckling restrained braces (BRBs) as innovative seismic protection devices. For this purpose, 4-, 8- and 12-story steel bare frames were designed with 6.5 m equal span length and 4 m story height. Thereafter, they were seismically improved by mounting the VDs and BRBs in three patterns, namely outer bays, inner bays, and all bays over the frame heights. The structures were modeled using SAP 2000 software and evaluated by the nonlinear time history analyses subjected to the six natural ground motions. The seismic responses of the structures were investigated for the lateral displacement, interstory drift, absolute acceleration, maximum base shear, and time history of roof displacement. The results clearly indicated that the VDs and BRBs reduced seismic demands significantly compared to the bare frame. Moreover, the all-bay pattern performed better than the others.


2012 ◽  
Vol 234 ◽  
pp. 96-101 ◽  
Author(s):  
Donato Cancellara ◽  
Fabio de Angelis

In the present work we have analyzed a particular base isolation system for the seismic protection of a multi-storey reinforced concrete (RC) building. The viscous dampers and friction sliders are the devices adopted in parallel for realizing the base isolation system. The base isolation structure has been designed and verified according to European seismic code EC8 and by considering for the friction sliders the influence of the sliding velocity on the value of the friction coefficient. A dynamic nonlinear analysis for a three-dimensional base isolated structure has been performed. Recorded accelerograms for bi-directional ground motions have been used which comply with the requirements imposed by EC8 for the representation of a seismic action in a time history analysis. In this paper a comparative analysis is presented between the base isolated structure with the described hybrid base isolation system and the traditional fixed base structure.


Author(s):  
Dion Marriott

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.


2020 ◽  
Vol 156 ◽  
pp. 05026
Author(s):  
Fauzan ◽  
Afdhalul Ihsan ◽  
Mutia Putri Monika ◽  
Zev Al Jauhari

The amount of potential investment in Padang City, Indonesia since 2017 attracted many investors to contribute to the city. One of the investments is a 12-story hotel that will be constructed in By Pass Street of the city. The hotel is located in a high seismic zone area, so the seismic base isolation has been proposed to be used in the hotel building. The main aim of using a seismic base isolation device is to reduce the inertia forces introduced in the structure due to earthquakes by shifting the fundamental period of the structure out of dangerous resonance range and concentration of the deformation demand at the isolation system. An analytical study on the Reinforced Concrete (RC) hotel building with and without rubber bearing (RB) base isolation is carried out using the response spectrum and time history analysis methods. The results show that internal forces and inter-story drift of the building with high damping rubber bearing (HDRB) are lower than that of the fixed base with a remarkable margin. From this study, it is recommended to use the HDRB base isolation for medium and high rise buildings with soft soil in Padang City, Indonesia.


Sign in / Sign up

Export Citation Format

Share Document