scholarly journals The Effects of Using Different Seismic Bearing on the Behavior and Seismic Response of High-Rise Building

2017 ◽  
Vol 3 (3) ◽  
pp. 160-171 ◽  
Author(s):  
Saman Mansouri ◽  
Amin Nazari
Keyword(s):  
Seismic Response ◽  
Linear Time ◽  
Time History ◽  
Bending Moment ◽  
Vertical Axis ◽  
History Analysis ◽  
Lead Rubber Bearings ◽  
Rc Building ◽  
Rubber Bearings ◽  
Seismic Response Of Buildings

The effects of using different seismic bearings were investigated to reduce the seismic response of buildings by assuming the vulnerability of 20-story regular RC building in this paper. The method of this study was that the studied building was studied in three different models in terms of its connection to the foundation. In the first model, the structures were placed on the rigid bearing and in the second and third models; lead-rubber bearings and friction pendulum bearings were placed at the counter between the structure and foundation, respectively. Then, the dynamic analysis was used to assess the behaviour and seismic response of the mentioned models. The results of the study showed that the structures in the first model functioned like cantilever column that would become uniaxial and biaxial bending under the effects of earthquake around the vertical axis of structure. Due to the tensile (tension) weakness in concrete, seismic loads caused major cracks in the tension part of the structures according to the place of the neutral axis that could lead to the collapse of structure. In addition, the use of mentioned seismic bearings under the earthquake caused the structure like a semi-rigid box slid on this equipment that reduced the structure's stiffness and increased the period of the structure in comparison with the first model. Using the studied seismic bearings caused the displacement of the roof of the first and twentieth stories of the structure become approximately equal and prevented the creation of the bending moment in the first model. The results of non-linear time history analysis showed that using the studied seismic bearings caused the response of the structure reduced significantly when the structure was placed on rigid bearings. It could be very valuable regarding the limitation of the capacity of the structure's members.

Hybrid Vibration Control of Self-Anchored Cable-Stayed Suspension Bridge

2014 ◽  
Vol 919-921 ◽  
pp. 556-559
Author(s):  
Miao Feng
Keyword(s):  
Vibration Control ◽  
Time History ◽  
Suspension Bridge ◽  
Nonlinear Time History Analysis ◽  
Viscous Damper ◽  
History Analysis ◽  
Lead Rubber Bearings ◽  
Control Section ◽  
Rubber Bearings ◽  
Nonlinear Time History

Larger displacement and inter-force response of the structure will be produced when self-anchored cable-stayed suspension bridge in longitudinal earthquake. The optimized layout of viscous damper is done for self-anchored cable-stayed suspension bridge with the lead rubber bearings in the main tower, moreover, the nonlinear time-history analysis in the longitudinal seismic input be made. Comparing the analysis results above between the scheme with viscous damper and the scheme without isolation measures, analysis results show that inter-force and displacement of control section and control node are reduced greatly in hybrid vibration control.

Parameter Effect of Side Retainers on Seismic Response of Bridges with Flexible Rubber Bearings

2011 ◽  
Vol 255-260 ◽  
pp. 1280-1284
Author(s):  
Xiang Xu ◽  
Wei Qin Liu ◽  
Xiu Li Xu ◽  
Ding Zhou ◽  
Xue Hong Li ◽  
...  
Keyword(s):  
Seismic Response ◽  
Seismic Design ◽  
Time History ◽  
Relative Displacement ◽  
Nonlinear Time History Analysis ◽  
History Analysis ◽  
Nonlinear Contact ◽  
New Type ◽  
Rubber Bearings ◽  
Nonlinear Time History

This paper studies the parameter effect of side retainers on seismic response of bridges with flexible rubber bearings. The pounding effect between girder and side retainers is analyzed by the nonlinear time-history analysis. The pounding and sliding of bearings are simulated by the nonlinear contact elements. Comparative analysis of seismic performance of bridge with/without retainers is carried out. Furthermore, the seismic performances of ordinary retainers and new retainers are compared. Finally, the effect of side retainer parameters on seismic response of bridge is analyzed. The results indicate that the sliding of elastomeric pad bearing should be considered in seismic design. It is shown that the retainers can effectively restrain the relative displacement between girder and piers, and the new type of retainers can greatly reduce the pounding force. It is also proved that both stiffness and gap of the retainer have significant influences on the pounding force.

scholarly journals Effect of the Improved Pall Friction Damper on the Seismic Response of Steel Frames

2017 ◽  
Vol 7 (4) ◽  
pp. 1833-1837 ◽  
Author(s):  
P. H. Sarjou ◽  
N. Shabakhty
Keyword(s):  
Seismic Response ◽  
Linear Time ◽  
Steel Frames ◽  
Time History ◽  
Friction Damper ◽  
Base Shear ◽  
Absorbed Energy ◽  
Steel Bracing ◽  
History Analysis ◽  
Energy Absorbing

Energy-absorbing dampers are used to reinforce structures which are vulnerable to earthquakes. This study evaluates the performance of Improved Pall Frictional Dampers (IPFD) which is a type of Pall Frictional Damper (PFD). For this purpose, this study compares the performances of steel frames with concentric steel bracing reinforced by IPFD and steel frames with concentric steel bracing with no damper. Frames with different stories and pans were modelled in sap2000 and exposed to accelerograms of earthquakes for non-linear time history analysis. Results of analysis were studied; parameters such as story displacement, base shear and absorbed energy were compared in steel frames with damper and without damper.

Effects of Pier Stiffness on the Seismic Response of Continuous Bridges with Irregular Configuration

2014 ◽  
Vol 638-640 ◽  
pp. 1794-1802 ◽  
Author(s):  
Si Si Wei
Keyword(s):  
Seismic Response ◽  
Linear Time ◽  
Time History ◽  
Time History Analysis ◽  
The Other ◽  
Relative Stiffness ◽  
History Analysis ◽  
Non Linear ◽  
Internal Forces

The seismic response of 4-span continuous bridges with different configurations has been investigated. In the series of bridges studied, the height of the central pier varies from 5 m to 100 m, while the heights of all the other piers remain the same. Using non-linear time history analysis, the internal forces at the bottom of individual piers have been predicted for each case. The correlation between the relative stiffness of adjacent piers and the ratio between the seismic response at the bottom of adjacent piers has been studied. Based on the results, in order to guarantee approximately balanced seismic response among all piers of a given bridge, a range of the relative column stiffness of two adjacent piers has been proposed.

scholarly journals Performance of Moment Resisting RC Building Equipped with X-Plate Damper under Seismic and Blast Loading

2019 ◽  
Vol 9 (2) ◽  
pp. 2758-2762
Keyword(s):  
Reinforced Concrete ◽  
Linear Time ◽  
Time History ◽  
Reinforced Concrete Structure ◽  
History Analysis ◽  
Moment Resisting ◽  
Rc Building ◽  
Structural Responses ◽  
Rc Frame Buildings ◽  
Dynamic Excitations

This study is an attempt to evaluate the effects of blast induced vibrations and seismic ground vibrations on reinforced concrete structure equipped with X-plate dampers and also to study the response of structure against blast and seismic vibration which can be reduced by employing protective systems such as dampers. Moment-resisting RC frame buildings were analysed to evaluate the structural responses under dynamic excitations. Non-linear Time-history analysis has been conducted on reinforced concrete structures. The ground accelerations were analytically determined and model was created in SAP2000.

scholarly journals The implications of post-tensioning losses on the seismic response of Pres-Lam frames

2018 ◽  
Vol 51 (2) ◽  
pp. 57-69 ◽  
Author(s):  
Gabriele Granello ◽  
Alessandro Palermo ◽  
Stefano Pampanin ◽  
Tobias Smith ◽  
Francesco Sarti
Keyword(s):  
Seismic Response ◽  
Linear Time ◽  
Response Spectrum ◽  
Time History ◽  
Moment Capacity ◽  
History Analysis ◽  
Supplemental Damping ◽  
Column Joint ◽  
Post Tensioning ◽  
Wall Foundation

Since 2010, twelve post-tensioned timber (Pres-Lam) buildings have been constructed throughout the world. In high seismic areas, Pres-Lam technology typically combines unbonded post-tensioning tendons and supplemental damping devices to provide moment capacity to beam-column, wall-foundation or column-foundation connections. Over time creep within the timber elements leads to losses in post-tensioning forces reducing the connection moment capacity. This paper analyses how different post-tensioning loss scenarios, depending on the beam-column joint detailing, impact the building’s seismic response. Two case study buildings were designed and investigated using the Acceleration Displacement Response Spectrum (ADRS) method and Non-Linear Time History Analysis (NLTHA) to predict seismic performance. These buildings were considered to be located in areas of high and low seismic risk, leading to designs with and without the use of damping devices, respectively. The results show that the building with additional damping responded with similar peak displacements, even under extreme loss scenarios. In comparison, when supplemental damping was not used, peak displacements increased significantly with post tensioning losses.

scholarly journals Blast Response of Elevated Water Tank Staging with Metallic Damper

2021 ◽  
Vol 309 ◽  
pp. 01135
Author(s):  
Boda Balaraju ◽  
Atulkumar Manchalwar
Keyword(s):  
Linear Time ◽  
Structural Response ◽  
Time History ◽  
Bending Moment ◽  
Water Tank ◽  
Blast Response ◽  
History Analysis ◽  
Structural Responses ◽  
Elevated Water ◽  
Metallic Damper

In the present paper work an attempt has been made to study the dynamic behaviour of the elevated water tank staging by using x-plate metallic damper subjected to blast induced ground vibrations. The main objective of this study is to reduce the damage of the elevated water tank by providing structural response control devices. The water tank staging is modelled in SAP 2000 and non-linear time history analysis is carried out to know the performance of the metallic damper under four different intensity blast induced ground motions and comparing the performance of structure without damper case. After the completion of analysis, the results show that by using metallic damper bending moment, shear force and displacements are comparatively reduced when compared to the without damper case. From this study observed that metallic x-plate damper is effectively reduced the structural responses under blast excitations.

scholarly journals Record-to-record variability and code-compatible seismic safety-checking with limited number of records

2021 ◽  
Author(s):  
Fatemeh Jalayer ◽  
Hossein Ebrahimian ◽  
Andrea Miano
Keyword(s):  
Seismic Hazard ◽  
Linear Time ◽  
Time History ◽  
Time History Analysis ◽  
Seismic Safety ◽  
Hazard Curve ◽  
History Analysis ◽  
Non Linear ◽  
Seismic Hazard Curve ◽  
Cloud Analysis

AbstractThe Italian code requires spectrum compatibility with mean spectrum for a suite of accelerograms selected for time-history analysis. Although these requirements define minimum acceptability criteria, it is likely that code-based non-linear dynamic analysis is going to be done based on limited number of records. Performance-based safety-checking provides formal basis for addressing the record-to-record variability and the epistemic uncertainties due to limited number of records and in the estimation of the seismic hazard curve. “Cloud Analysis” is a non-linear time-history analysis procedure that employs the structural response to un-scaled ground motion records and can be directly implemented in performance-based safety-checking. This paper interprets the code-based provisions in a performance-based key and applies further restrictions to spectrum-compatible record selection aiming to implement Cloud Analysis. It is shown that, by multiplying a closed-form coefficient, code-based safety ratio could be transformed into simplified performance-based safety ratio. It is shown that, as a proof of concept, if the partial safety factors in the code are set to unity, this coefficient is going to be on average slightly larger than unity. The paper provides the basis for propagating the epistemic uncertainties due to limited sample size and in the seismic hazard curve to the performance-based safety ratio both in a rigorous and simplified manner. If epistemic uncertainties are considered, the average code-based safety checking could end up being unconservative with respect to performance-based procedures when the number of records is small. However, it is shown that performance-based safety checking is possible with no extra structural analyses.

Nonlinear Dynamic Analysis of the Damping Frame Structure System

2012 ◽  
Vol 594-597 ◽  
pp. 886-890 ◽  
Author(s):  
Gan Hong ◽  
Mei Li ◽  
Yi Zhen Yang
Keyword(s):  
Energy Dissipation ◽  
Seismic Response ◽  
Nonlinear Dynamic ◽  
Time History ◽  
Time History Analysis ◽  
Frame Structure ◽  
Force Model ◽  
Operating Characteristics ◽  
Restoring Force ◽  
History Analysis

Abstract. In the paper, take full account of energy dissipation operating characteristics. Interlayer shear-frame structure for the analysis of the Wilson-Θmethod ELASTOPLASTIC schedule, the design of a nonlinear dynamic time history analysis procedure. On this basis, taking into account the restoring force characteristics of the energy dissipation system, the inflection point in the restoring force model treatment, to avoid a result of the calculation results of distortion due to the iterative error. A frame structure seismic response time history analysis results show that: the framework of the energy dissipation significantly lower than the seismic response of the common framework, and its role in the earthquake when more significant.

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