scholarly journals Seismic Response of Retrofitting for High Rise R.C. Structure by Using R.C.C Jacketing and Steel Wrapping

2021 ◽  
Vol 9 (VII) ◽  
pp. 2307-2318
Author(s):  
Sachin Motghare
Keyword(s):  
Seismic Design ◽  
Time History ◽  
Time Frame ◽  
Mode Shapes ◽  
Base Shear ◽  
Seismic Excitations ◽  
Edge Structure ◽  
High Rise ◽  
Fema 356 ◽  
Principle Objective

A seismic design depends on mix of solidarity and pliability. Incessant seismic aggravations, the structure are relied upon to stay in the flexible reach. By thinking about the real powerful nature of ecological unsettling influences, more upgrades are required in the plan methodology. What's more, some development procedures are utilized to fortify the current structures i.e. distinctive retrofitting methods. All these technique shave their own benefits. The principle objective of the current examination is to dissect the conduct of Retrofitted fabricating i.e. provision of steel jacketing in expanding the presentation of building. The current examination targets checking the adequacy of multi-story outline structures utilizing retrofitting strategies for the seismic excitations. The Retrofitted building for example arrangement of steel jacketing is investigated and contrasted and exposed edge structure by utilizing time history and sucker examination strategy by utilizing Commercial programming SAP2000 v16 is utilized for examination. The responses of the structure are compared by considering various boundaries i.e. displacement, base shear, plastic pivots, time-frame of mode shapes from FEMA – 356. The outcome shows that plastic pivot formation during quake at shaft section intersection can further developed execution with use retrofitting strategy for example steel jacketing.

scholarly journals Comparative Study on seismic analysis and Retrofitting of an Existing Building

2021 ◽  
Vol 9 (VII) ◽  
pp. 3018-3027
Author(s):  
Muniraju J
Keyword(s):  
Seismic Analysis ◽  
Time History ◽  
Time Frame ◽  
Base Shear ◽  
Existing Building ◽  
Building Model ◽  
Removal Time ◽  
Stacking Condition ◽  
Similar Code ◽  
The Impact

The target of this undertaking is to examine and comprehend the impact of utilizing retrofitting strategies on a structure against the seismic unique burden. The investigation is completed on four models of a G+4 building. Model 1 was not exposed to any seismic burden and was discovered to be protected against the arrangement load and live burden and its blend. Model 2 was exposed to dynamic seismic burden and its mix and the disappointment of primary individuals was noted. Accordingly retrofitting was done in the following two models. In Model 3 the structure was retrofitted with bracings were as in Model 4 section jacketing and in Model 5 shear divider were utilized. Boundaries like removal, time history, firmness and base shear were chosen subsequent to leading a careful writing audit. Time-frame of the structure was ascertain according to IS1893-2016, and Zone factor was chosen as 0.1 and 0.16 alongside significance factor as 1 and Soil type as II from a similar code. Then, at that point the same static examination and reaction range investigation was completed on Models 2,3,4 and 5 individually and there results were arranged. In light of the outcomes acquired for the given boundaries and dynamic stacking condition it was reasoned that retrofitting the structure will in general decrease the impacts of dynamic stacking on the design. Further it was noticed that retrofitting the structure with shear divider gave the best suitable outcomes. As it diminished the time-frame of the structure by 32.72% and furthermore lessen the sidelong relocation and story float in both X and Y heading by a decent edge.

Comparison between fixed base and isolated base in seismic response of high-rise buildings: a case study

2020 ◽  
Vol 6 (4) ◽  
pp. 204
Author(s):  
Anas M. Fares
Keyword(s):  
Response Spectrum ◽  
Soft Soil ◽  
Structural Response ◽  
Time History ◽  
Soil Condition ◽  
Soil Conditions ◽  
Spectral Acceleration ◽  
Base Shear ◽  
High Rise ◽  
Fixed Base

In this study, the influence of soil condition under the isolated and fixed bases is studied by using ETABS 16 software for the high-rise regular building. A regular building with 10 floors is modeled and the results are obtained for story displacements, story shear forces and spectral acceleration according to Uniform Building Code 97 (UBC-97) code. The time history analysis has been performed by using 1999 Izmit earthquake record. 3 types of soil which had different stiffnesses are considered in this study. The results show that the value of base shear increases when the soil stiffness decreases. It also noticed that the spectral acceleration is larger in soft soil condition than that of other soil conditions; and this confirms that the structural response spectrum is associated with the soil condition. In addition, when using base isolated building the drift of lower floors will be larger than that of using base isolated, but in the upper floors the drifts of fixed base building will be larger than that of the isolated base building. Finally, time history method in the seismic design will produce base shear less than that from equivalent static method, so calibration factor for design purpose shall be used.

Research on Mechanical Behaviors of Composite Frame and Reinforced Concrete Core Hybrid Structures in High-Rise Buildings

2010 ◽  
Vol 163-167 ◽  
pp. 2056-2062
Author(s):  
Shu Yun Zhang ◽  
Guo Liang Bai ◽  
Lai Shun Zhao
Keyword(s):  
Reinforced Concrete ◽  
Natural Vibration ◽  
Time History ◽  
Hybrid Structures ◽  
Mode Shapes ◽  
Mechanical Behaviors ◽  
Concrete Core ◽  
High Rise ◽  
Composite Frame ◽  
Rigid Model

For mechanical behaviors of composite frame and reinforced concrete core hybrid Structures in high-rise buildings, the three-dimension finite element models were established, modal analysis and elastic time-history analysis were finished, the cooperative work mechanism between frame and core was researched, the dynamic characteristics and seismic response of the hybrid structures under different connection type were studied. the results indicate that the stiffness characteristic of the hybrid structures should be taken between 1 to 2 so that two sub-structure can reasonably afford the internal force, the connection between frame and core bring differences in mode shape and natural vibration periods, the natural vibration periods of hinged model are greater than periods of rigid model, the mode shapes with mainly floor vibration are more likely to appear in hinged model, the connection would lead to significant changes in the deformation and distribution of inner force, the axial force of frame columns would significantly increase for the rigid connection, the shear and bending moment of frame columns would increase for the hinged connection, it was proposed that the hybrid structures should be separately analyzed with hinge model and rigid model for ensuring the frame columns have sufficient capacity of the shearing and bending both.

scholarly journals Behaviour of Thermal Power Plant Boiler Support Steel Structure under Seismic Excitations

2019 ◽  
Vol 8 (1) ◽  
pp. 74-80
Author(s):  
R. Arun Kumar . ◽  
C. Umarani .
Keyword(s):  
Power Plant ◽  
Thermal Power Plant ◽  
Thermal Power ◽  
Time History ◽  
Steel Structure ◽  
Mode Shapes ◽  
Seismic Excitations ◽  
Static And Dynamic Analysis ◽  
Power Plant Boiler ◽  
Plant Boiler

Static and dynamic analysis of a thermal power plant boiler support steel structure is carried out to study its behaviour and responses. Non-Linear Time History Analysis (NLTHA) method is adopted to study the behaviour and response of the structure in addition with Equivalent Static Analysis (ESA) and Response Spectrum Analysis (RSA) methods using SAP2000 software application. Though NLTHA method is not used extensively in Indian boiler support structure design practices, in the present study, an attempt is made to study about the realistic behaviour and performance of boiler support steel structure using NLTHA. Three different ground motions are used for analysing the boiler support steel structure with compatible scale factors and during the analysis, behaviour of the structure under different seismic excitations are usually compared in terms of [5] load-deflection, moment-rotation, moment-curvature and stress-stain relationships. Hence it is found that NLTHA method provides more accurate and dynamic results compared to the ESA and RSA methods. Various seismic demand parameters like mode shapes, displacements, drifts, base shear forces, floor accelerations and floor response spectra curves are presented in the results to understand the behaviour and response of the boiler support steel structures during the seismic excitations.

scholarly journals Soil-pile-structure interaction effects on high-rise building under seismic shaking

2019 ◽  
Vol 2 (1) ◽  
pp. 153-164
Author(s):  
Umesh Jung Thapa ◽  
Ramesh Karki
Keyword(s):  
Soil Structure ◽  
Seismic Analysis ◽  
Time History ◽  
Soil Structure Interaction ◽  
Base Shear ◽  
Structure Interaction ◽  
High Rise ◽  
High Rise Building ◽  
History Analysis ◽  
Fixed Base

In this paper, study of the response (base shear, time period, storey drift, storey displacement) of a structure is done for the tall building including basement with fixed base and with pile foundation considering Soil Structure Interaction (SSI). Finite element based program ETABS2016 v16.1.0 is used for the analysis of the superstructure. Seismic analysis is done to get the dynamic response of superstructure for two types of model,one model is with fixed baseand second is Model with Winkler spring for Chhaya Center, Thamel, a high rise building with 14 story including double basements. Itisobserved with the consideration of Soil Structure Interaction (SSI). The soil is replaced by spring and assigned at joints. El Centro earthquake (1940) is used for time history analysis. The response obtained due to SSI effect is compared with fixed based model. Results of analysis presented include the comparison of natural periods, base shears, displacements and overturning moment. It is observed that the natural periods increase and the base shears decrease as the base become more flexible.

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.

Seismic performance of reinforced concrete ductile moment-resisting frame buildings located in different seismic regions

1992 ◽  
Vol 19 (4) ◽  
pp. 688-710 ◽  
Author(s):  
T. J. Zhu ◽  
W. K. Tso ◽  
A. C. Heidebrecht
Keyword(s):  
Reinforced Concrete ◽  
Seismic Design ◽  
Ground Motions ◽  
Base Shear ◽  
High Rise ◽  
Moment Resisting Frame ◽  
Short Period ◽  
Frame Buildings ◽  
Moment Resisting ◽  
Seismic Regions

Seismic areas in Canada are classified into three categories for three different combinations of acceleration and velocity seismic zones (Za < Zv, Za = Zv, and Za > Zv), and ground motions in different zonal combination areas are expected to have different frequency characteristics. The National Building Code of Canada specifies different levels of seismic design base shear for short-period buildings located in areas with different zonal combinations. The specification of seismic design base shear for long-period buildings is directly tied to zonal velocity, irrespective of seismic zonal combination. This paper evaluates the seismic performance of both high-rise long-period and low rise short-period reinforced concrete ductile moment-resisting frame buildings located in seismic regions having Za < Zv, Za = Zv, and Za > Zv. Two frame buildings have 10 and 18 storeys were used as structural models for high-rise buildings, while a set of four-storey buildings were used to represent low-rise buildings. All buildings were designed to the current Canadian seismic provisions and concrete material code. Three groups of earthquake records were selected as representative ground motions in the three zonal combination regions. The inelastic responses of the designed buildings to the three groups of ground motions were analyzed statistically. The results indicate that the distribution of inelastic deformations is significantly different for high-rise frame buildings situated in seismic regions with Za < Zv, Za = Zv, and Za > Zv. Inelastic deformation is concentrated in the lower storeys for high-rise buildings located in Za < Zv areas, whereas significant inelastic deformation can develop in the upper storeys for high-rise buildings situated in Za > Zv regions. The use of three different levels of seismic design base shear for short-period structures improves the consistency of ductility demands on low-rise buildings situated in the three different zonal combination regions. Despite the use of appropriate design base shears for different seismic regions, the ductility demands for these low-rise buildings are relatively high. To avoid excessive ductility demands, it is suggested that the seismic strengths for low-rise short-period buildings should not be significantly reduced from their elastic design base shears. Key words: earthquake, ground motion, seismic, design, reinforced concrete, frame buildings, beams, columns, ductility.

Key Points Analysis for Seismic Design of Super High-Rise Building

2013 ◽  
Vol 423-426 ◽  
pp. 1230-1233
Author(s):  
Ting Yu Mei ◽  
Lang Wu
Keyword(s):  
Seismic Design ◽  
Design Method ◽  
Response Spectrum ◽  
Time History ◽  
Stage Design ◽  
High Rise ◽  
High Rise Building ◽  
History Analysis ◽  
Key Points ◽  
And Performance

In recent years, high-rise buildings have developed very rapidly in our country. Because of the particularity of the high-rise building, more strictly technical measures should be taken in seismic design to ensure security. Three level fortifications, two stage design method have been used for seismic design in our country. Combined with the practical, the key points of response spectrum, time history analysis and performance design which related to seismic design of high-rise buildings were analyzed.

Effects of Base Isolation on Multi-Layer and High-Level Framework

2011 ◽  
Vol 255-260 ◽  
pp. 2568-2572
Author(s):  
Hai Qing Liu ◽  
Xiao Guo ◽  
Hao Wang
Keyword(s):  
Seismic Waves ◽  
Base Isolation ◽  
Equations Of Motion ◽  
Time History ◽  
Structural System ◽  
Base Shear ◽  
High Rise ◽  
Isolated Structures ◽  
Rubber Bearings ◽  
High Level

This paper expounded the basic principle of the base-isolated structures. Established the equations of motion of single particle and multi-particle base isolation structural system. Adopted multi-layer and high-level framework groups, added laminated rubber bearings in the bottom respectively, input EL Centro seismic waves, and then the modal, time-history, base shear are compared and analyzed. By comparing the results obtained: base-isolated structure used in high-rise building can decrease a certain degree of the seismic response, in the multi-layer building the effect was more apparent. It also confirmed that the application of base isolation on multi-layer and high-level framework in the existing conditions still had some limitations.

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