scholarly journals Seismic Design and Performances of Frame Structures Connected to a Strongback System and Equipped with Different Configurations of Supplemental Viscous Dampers

2021 ◽  
Vol 7 ◽  
Author(s):  
Michele Palermo ◽  
Vittoria Laghi ◽  
Giada Gasparini ◽  
Stefano Silvestri ◽  
Tomaso Trombetti
Keyword(s):  
Time History ◽  
Elastic Field ◽  
Frame Structure ◽  
Viscous Dampers ◽  
Single Degree Of Freedom ◽  
Fluid Viscous Dampers ◽  
Moment Resisting Frame ◽  
Moment Resisting ◽  
Supplemental Dampers ◽  
Dynamic Time

The paper investigates the dynamic behavior of structural systems obtained by connecting a moment-resisting frame structure with a vertical rigid truss pinned at the base, known in literature as “strongback,” and equipped with added fluid-viscous dampers. The strongback, designed in order to remain in the elastic field under strong seismic ground motion, acts as a mast by imposing to the structure a linear lateral deformed shape. By regularizing the lateral drift profile of the structure, the strongback limits undesired effects such as weak-storey mechanisms, damage concentration and residual drifts. In addition, when supplemental dampers are inserted in the structure, a considerable amount of energy can be dissipated, thus reducing the peak seismic response. The aim of the work is twofold: i) to provide analytical formulations for the preliminary design of added dampers based on the Generalized Single Degree Of Freedom (GSDOF) concept, and ii) to evaluate the increase in energy dissipation capabilities for selected dampers configurations thanks to the presence of the strongback. The formulas are developed for different configurations of added viscous dampers: dampers inserted within the frame between all or selected consecutive storeys (inter-storey placement) and dampers located at the base of the strongback to realize a rigid “dissipative tower.” The effectiveness of the dampers configurations is evaluated through dynamic time-history analyses.

scholarly journals Seismic Analysis and Design of Multi Storey RC Buildings with and without Fluid Viscous Dampers

2021 ◽  
Vol 9 (VII) ◽  
pp. 53-57
Author(s):  
Prof. Sanjay Bhadke
Keyword(s):  
Natural Hazards ◽  
Seismic Analysis ◽  
Seismic Zone ◽  
Viscous Dampers ◽  
Analysis And Design ◽  
Fluid Viscous Dampers ◽  
Moment Resisting Frame ◽  
Frame Building ◽  
Moment Resisting ◽  
Sudden Transition

Earthquakes are one among the foremost destructive of natural hazards. Earthquake occurs due to sudden transition motion of the ground as a result of release of energy in a matter of few seconds. This recent events remind us of the vulnerability of our society to natural hazards. The protection of civil structures, including material content and human occupants is, doubtless, a worldwide priority. The challenge of structural engineers is to raised withstand these natural hazards. In the present study reinforced concrete moment resisting frame building of G+20 are considered. The building is taken into account to be located in the seismic zone (v) and intended for commercial purpose. Model-I Building without dampers, Model-II –Building with dampers. The building of G+20 has been modeled by providing with and without damper providing all parameters using S A P 2 0 0 0 software. Results show that using fluid viscous dampers to putting together effectively reduce the building responses by selecting optimum damping coefficient i.e. when the building is connected to the fluid viscous dampers (FVD) can control both displacements and accelerations of the building. Further damper at appropriate locations can significantly reduce the earthquake response.

scholarly journals EVALUASI JARAK AMAN ANTARA STRUKTUR SRPM TINGGI DENGAN STRUKTUR SRPM DISEBELAHNYA TERHADAP GEMPA

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Ade Faisal ◽  
Tondi Amirsyah Putera ◽  
Mariden Purba
Keyword(s):  
Time History ◽  
Tall Buildings ◽  
Soil Conditions ◽  
Safe Distance ◽  
High Rise ◽  
Moment Resisting Frame ◽  
History Analysis ◽  
Moment Resisting ◽  
Dynamic Time ◽  
Storey Building

Pembangunan gedung-gedung tinggi menjadi salah satu alternatif yang di pilih karena keterbatasan dan mahalnya lahan diperkotaan sementara tingkat permintaan ruang untuk berbagai kegiatan semakin tinggi. Hal ini menyebabkan gedung-gedung bertingkat sering dibangun saling berdekatan satu dengan yang lainnya. Benturan dapat terjadi pada dua bangunan gedung bertingkat yang bersebelahan apabila jarak antara dua bangunan lebih kecil dari simpangan maksimum yang terjadi akibat beban gempa. Studi ini bertujuan untuk mencari jarak aman antara dua bangunan tinggi yang bersebelahan. Gedung yang direncanakan 2 model menggunakan SRPM dengan material beton bertulang yang terletak di kota Medan dengan kondisi tanah sedang. Model  pertama (Model 1) direncanakan memiliki tinggi 28,5 meter terdiri dari 8 lantai, sedangkan Model kedua (Model 2) direncanakan memiliki tinggi 35,5 meter terdiri dari 10 lantai. Analisa yang digunakan pada studi ini yaitu analisis dinamik riwayat waktu. Nilai simpangan yang terjadi pada gedung  8 lantai (Model 1) untuk arah x sebesar 80,87 mm dan untuk arah y sebesar 79,35 mm. Simpangan yang  terjadi pada gedung 10 lantai (Model 2) untuk arah x sebesar 113,33 mm dan untuk arah y sebesar 112,39 mm. Hasil analisa yang dilakukan menunjukkan jarak aman antara gedung 8 lantai dengan gedung 10 lantai adalah sebesar 2,1 meter, sedangkan jarak aman antara gedung 10 lantai dengan gedung 10 lantai adalah sebesar 2,2 meter.  Kata Kunci : Analisis Riwayat Waktu, Benturan Antar Gedung, Jarak Antar Gedung, Simpangan  ABSTRACT The construction of tall buildings became one of alternative that was chosen because of the urban land limitations and the cost. At the same time the space demand for various urban activities is increased. It is caused the high-rise buildings are often built very close to one another. The collision can be occurred if two adjacent building if the distance between the two building is smaller than the maximum drift caused by the earthquake action. This study aims to plan a safe distance between two adjacent high-rise buildings. The planned building two models using Moment Resisting Frame with reinforced concrete material that is located in the city Medan with moderate soil conditions. The first model (Model 1) has a height of 28.5 meters is planned consists of 8 floors, while the second model (Model 2) planned to have a height of 35.5 meters consists of 10 floors. The analysis used in this study is the analysis of dynamic time history. The displacement value which occurred on 8 storey building (Model 1) to the x direction by 80.87 mm and for the y direction by 79.35 mm. The displacement occurs in the building 10 floors (Model 2) to the x direction of 113.33 mm and for the y direction of 112.39 mm. The results of analysis indicate that the safe distance between 8 storey building with 10 floors of the building is 2.1 meters, while the safe distance between buildings 10 floors with 10 storey building is 2.2 meters. Keywords: Time History Analysis, Clash Between Buildings, Distance Between Buildings, Deviation

Seismic performance of ductile medium height reinforced concrete frame buildings designed in accordance with the provisions of the 1995 National Building Code of Canada

1999 ◽  
Vol 26 (5) ◽  
pp. 606-617 ◽  
Author(s):  
A C Heidebrecht ◽  
N Naumoski
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Frame Structure ◽  
Performance Criteria ◽  
Building Code ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Moment Resisting Frame ◽  
Moment Resisting ◽  
Interstorey Drift

This paper describes an investigation into the seismic performance of a six-storey ductile moment-resisting frame structure located in Vancouver and designed and detailed in accordance with the seismic provisions of the National Building Code of Canada (1995). Both pushover and dynamic analyses are conducted using an inelastic model of the structure as designed and detailed. The structural performance of a number of design variations is evaluated using interstorey drift and member curvature ductility response as performance measures. All frames studied are expected to perform at an operational level when subjected to design level seismic excitations and to meet life safe performance criteria at excitations of twice the design level.Key words: seismic, building, frames, ductile, design, performance, reinforced concrete, code.

scholarly journals Retrofit Existing Frame Structures to Increase Their Economy and Sustainability in High Seismic Hazard Regions

2019 ◽  
Vol 9 (24) ◽  
pp. 5486 ◽  
Author(s):  
Shuang Li ◽  
Jintao Zhang
Keyword(s):  
Optimum Design ◽  
Computational Cost ◽  
Time History ◽  
Economic Benefits ◽  
Frame Structure ◽  
Viscous Damper ◽  
Viscous Dampers ◽  
Frame Model ◽  
Rare Earthquake ◽  
Original Frame

The study proposes a retrofitting method with an optimum design of viscous dampers in order to improve the structural resistant capacity to earthquakes. The retrofitting method firstly uses a 2D frame model and places the viscous dampers in the structure to satisfy the performance requirements under code-specific design earthquake intensities and then performs an optimum design to increase the structural collapse-resistant capacity. The failure pattern analysis and fragility analysis show that the optimum design leads to better performance than the original frame structure. For regular structures, it is demonstrated that the optimum pattern of viscous damper placement obtained from a 2D frame model can be directly used in the retrofitting of the 3D frame model. The economic loss and repair time analyses are conducted for the retrofitted frame structure under different earthquake intensities, including the frequent earthquake, the occasional earthquake, and the rare earthquake. Although the proposed method is based on time-history analyses, it seems that the computational cost is acceptable because the 2D frame model is adopted to determine the optimum pattern of viscous damper placement; meanwhile, the owner can clearly know the economic benefits of the retrofitting under different earthquake intensities. The retrofitting also causes the frame to have reduced environmental problems (such as carbon emission) compared to the original frame in the repair process after a rare earthquake happens.

scholarly journals Comparison of Scaling Ground Motions Using Arithmetic with Logarithm Values for Spectral Matching Procedure

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Rui Zhang ◽  
Dong-sheng Wang ◽  
Xiao-yu Chen ◽  
Hong-nan Li
Keyword(s):  
Ground Motions ◽  
Time History ◽  
Response Spectra ◽  
Time History Analysis ◽  
Spectral Matching ◽  
Moment Resisting Frame ◽  
History Analysis ◽  
Moment Resisting ◽  
Structural Responses ◽  
Structural Time

In recent studies, spectral matching is the most commonly proposed method for selecting earthquake records for time-history analysis of structures. However, until now, there have been no serious investigations of the effects of coordinate values on the scaling of ground motions. This paper investigated the influence of using arithmetic and logarithmic values of response spectra in spectral matching procedures (i.e., ASM and LSM methods) on the results of nonlinear structural time-history analysis. Steel moment resisting frame structures of the 3-, 9-, and 20-stories, which represent low-, medium-, and high-rise buildings, respectively, were used as examples. Structural benchmark responses were determined by calculating the arithmetic mean and median of peak interstory drift ratio (PIDR) demands based on the three record sets developed by the American SAC Steel Project. The three record sets represent seismic hazard levels with 50%, 10%, and 2% probabilities exceeded in 50 years, and their average acceleration spectra were also taken as the target spectrum. Moreover, another 40 record components for selection were scaled both by ASM and LSM methods. The seven components whose spectra were best compatible with the target spectra were selected for the structural time-history analysis. The scale factors obtained by the LSM method are nearly larger than that of the ASM method, and their ranking and selection of records are different. The estimation accuracies of structural mean (median) responses by both methods can be controlled within an engineering acceptable range (±20%), but the LSM method may cause larger structural responses than the ASM method. The LSM method has a better capacity for reducing the variability of structural responses than the ASM method, and this advantage is more significant for longer-period structures (e.g., 20-story structure) with more severe nonlinear responses.

scholarly journals Improving the Dynamic Behavior of Adjacent Buildings with Fluid Viscous Dampers

2016 ◽  
Vol 10 (12) ◽  
pp. 245
Author(s):  
Solmaz Yaghobzadeh
Keyword(s):  
Control Systems ◽  
Dynamic Behavior ◽  
Time History ◽  
Tall Buildings ◽  
System Response ◽  
Response Analysis ◽  
Viscous Dampers ◽  
Fluid Viscous Dampers ◽  
Adjacent Buildings ◽  
The Impact

Explained ways to strengthen structures against lateral dynamic loads can be divided into two broad categories. The first part is the structural systems for controlling seismic displacement and second part is the use of applying systems of control forces. Response mechanism of structures using control systems are improved and greatly reduce the risks of damage caused by earthquakes.Today the use of these control systems in buildings have been increased and it’s important to reduce vibration of structures is felt more than ever. As well as to improve the dynamic behavior of nearby buildings, control systems can be installed between adjacent buildings as activated, semi-active and inactivated systems. The main purpose of this study is the use of control systems in two similar adjacent buildings to reduce the entire system response which will be the analytical study of the impact of viscous dampers to control system performance.In order to analysis of modeling to improve the dynamic behavior of different adjacent buildings connected with dampers, two models of the original sample will be examined in this article. All examples are different from each other and to elicit response analysis and time history software SAP 2000was used. According to the results the effect of fluid viscous dampers for tall buildings compared shorter building, is less. Also, these dampers for adjacent buildings with different heights than buildings with same height are more effective.

Sign in / Sign up

Export Citation Format

Share Document