Seismic Performance Assessment, Retrofitting and Loss Estimation of an Existing Non-Engineered Building in Nepal

2020 ◽  
pp. 43-70
Author(s):  
Rakesh Dumaru ◽  
Hugo Rodrigues ◽  
Humberto Varum
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Shear Capacity ◽  
Ambient Vibration ◽  
Seismic Performance Assessment ◽  
Existing Building ◽  
Damage States ◽  
Uniform Drift ◽  
Dynamic Time ◽  
Adaptive Pushover

<p>The non-engineered building built before 2004 remained after Gorkha earthquake although such structures demonstrate seismic deficient. Therefore, the present study aims to carry out detail seismic performance of such building to investigate as-built seismic performance and its performance after intervention of retrofit measures. Two in situ tests were performed, which includes Schmidt hammer test and ambient vibration test. The adaptive pushover analysis and dynamic time history analyses were performed for as-built and retrofitted building. The retrofit measures increase the stiffness and maximum base shear capacity of the buildings. In addition, such retrofit measures improved single storey drift concentration in existing building such that uniform drift profile can be attained. Furthermore, the probability of exceeding damage states can be significantly reduced and mainly found to be more effective in minimizing higher damage states, such as partial collapse and collapse states. The maximum expected annual loss occurs between 0.1 g and 0.2 g PGA (Peak Ground Acceleration). It was revealed that the steel braced building was found to be relatively more effective in enhancing the seismic performance, whereas reinforced concrete shear wall found more economic feasible retrofit measure for this particular building.</p>

Strengthening Research in the Longitudinal Frames of Prefabricated Structures with Viscous Dampers

2013 ◽  
Vol 671-674 ◽  
pp. 782-785
Author(s):  
Bin He ◽  
Jin Lai Pang ◽  
Cheng Qing Liu
Keyword(s):  
Seismic Performance ◽  
Pushover Analysis ◽  
Vertical Direction ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Viscous Dampers ◽  
Existing Building ◽  
Concrete Frame ◽  
Uniform Drift ◽  
Nonlinear Time History

For the lack of research in the longitudinal frame of prefabricated structure for its weak lateral stiffness, pushover analysis is conducted to evaluate the seismic performance of a fabricated concrete frame. Based on case study, the strengthening strategies with viscous dampers are analyzed. In view of the undesirable drift distribution and failure mode in the existing building, it is believed that arrangement of dampers should be designed to attain a uniform drift distribution. Based on the nonlinear time history analysis method, the strategy of damper allocation in vertical direction of the structure is investigated .Results indicate that a proper design might be attained based on the property of existing system, leading to a uniform drift distribution and better seismic performance.

Seismic Behavior of Super High-Rise Frame-Core Wall Structure

2012 ◽  
Vol 226-228 ◽  
pp. 967-971
Author(s):  
Ji Xing Yuan ◽  
Qing Zhang
Keyword(s):  
Failure Mode ◽  
Seismic Performance ◽  
Time History ◽  
Frame Structure ◽  
Wall Structure ◽  
Coupling Beams ◽  
High Rise ◽  
Seismic Shear ◽  
Earthquake Force ◽  
Dynamic Time

In this paper a super high-rise frame-core wall as an example, It was analyzed the frame-core wall structure system under action of earthquake force features, set reasonable seismic performance objectives, analysis the structure reasonable failure mode, made it have enough bearing capacity and ductility for a reasonable design of frame and coupling wall-beam, could make the frame-core wall structure with multiple seismic fortification lines, improve the seismic performance of the frame-core wall structure. Finally, the action of earthquake deformation and seismic shear force distribution was analyzed through the elastic dynamic time-history analysis. After a reasonable optimization analysis showed: Frame-core wall structure could have three seismic fortification lines: coupling beams, core wall, frame structure, and had enough energy dissipation ability at the same time, could form the rational failure mode, improved the seismic performance of the structure.

Analysis on Seismic Performance of Corrugated Steel Web Continuous Rigid Frame Bridge

2014 ◽  
Vol 501-504 ◽  
pp. 1471-1476
Author(s):  
Yi Qiang Wang ◽  
Bing Bing Fan ◽  
Liang Li
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Element Analysis ◽  
Continuous Rigid Frame Bridge ◽  
Rigid Frame ◽  
History Analysis ◽  
The Finite Element Analysis ◽  
Corrugated Steel Web ◽  
Dynamic Time ◽  
Rigid Frame Bridge

Corrugated steel web continuous rigid frame bridge is a new form of bridge. Using the finite element analysis software Midas Civil to analyze dynamic characteristics of the corrugated steel web continuous rigid frame bridge in a method of subspace iron and the nonlinear dynamic time history analysis method is used to analyze the seismic performance of the bridge, then compared with the ordinary concrete web continuous rigid frame bridge. The results show that the natural frequency of the corrugated steel web continuous rigid frame bridge is smaller than that of the concrete web continuous rigid frame bridge, and the seismic performance of the corrugated steel web continuous rigid frame bridge is superior to that of concrete web continuous rigid frame bridge, the improvement of the seismic performance of piers is most significant.

scholarly journals Simplified Approach for Seismic Performance Assessment of Dry-Joint Masonry Arch Bridges

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 313
Author(s):  
Ismail Ozan Demirel ◽  
Alper Aldemir
Keyword(s):  
Performance Assessment ◽  
Seismic Performance ◽  
Structural Characteristics ◽  
Time History ◽  
Collapse Mechanism ◽  
Seismic Performance Assessment ◽  
Masonry Arch ◽  
Simplified Approach ◽  
The North ◽  
Arch Bridges

The seismic performance assessment of dry-joint masonry arches is challenging because of their unique structural characteristics. Widely used assessment methods developed for frame-type structures require the use of a material-dependent section response. In contrast, the response of a dry-joint arch is not dependent on the material capacity but characterized by the sustainment of stability, primarily depending on rigid body rotation or sliding motion at the interfaces between the adjacent voussoirs. A hybrid methodology, combining a simple finite element micro model with principles of limit analysis method, is proposed in this work for the seismic performance assessment of these structures. The nonlinearity is concentrated at interfaces of the model by means of shear and compression-only axial springs. Kinematic conditions yielding a possible collapse mechanism were traced at every step of the time history analysis by checking the failure of individual interfaces. The procedure is applied to an ancient dry-joint Roman arch bridge in close proximity to the North Anatolian fault subject to significant seismic risk. Along with the performance of the system in its current state, the effects of retrofitting measures were investigated in the scope of this study.

Influence Factors and Repair Effects of Seismic Damage to a Box Section Steel Pier

2019 ◽  
Vol 13 (03n04) ◽  
pp. 1940001
Author(s):  
Zhongqiu Fu ◽  
Dongyang Wu ◽  
Liang Fang ◽  
Donghua Chen ◽  
Bohai Ji
Keyword(s):  
Energy Dissipation ◽  
Bearing Capacity ◽  
Seismic Performance ◽  
Nonlinear Dynamic ◽  
Time History ◽  
Time History Analysis ◽  
Steel Plates ◽  
Box Section ◽  
History Analysis ◽  
Dynamic Time

The seismic performance of a steel pier of box section was studied through low-cycle cyclic testing. The damaged specimens were repaired by filling with concrete and welding steel plates. The low-cycle cyclic test was then repeated. The effects of repairs were investigated by comparison of failure mode, energy dissipation performance, and ductility before and after repair. To supplement the data, the influence of different factors on the seismic bearing capacity and ductility of steel piers were analyzed by finite element method. The repair effects were compared by threshold of the displacement from the experiment. Based on the displacement angle response of the nonlinear dynamic time history analysis, the seismic performance is checked. The results show that repair had favourable effects on the damaged specimens. The horizontal bearing capacity and ductility of the specimens filled with concrete are significantly enhanced. Reinforcement by steel plates can increase the ductility and cumulative energy dissipation of the steel pier. An axial compression ratio of 0.2 and a concrete filling ratio of 30% are suggested. The horizontal bearing capacity can be improved by increasing the steel strength while the concrete strength shows little effect. The angular displacement from nonlinear dynamic time-history analysis was less than the test threshold, so the existing methods used for seismic performance verification are safe.

Study on the Seismic Performance of Cavity Walls Constraint Masonry Construction

2013 ◽  
Vol 724-725 ◽  
pp. 1702-1708
Author(s):  
Shu Hong Zuo ◽  
Hong Lu Bai ◽  
Li Hong Xiong ◽  
Ben Yi Liu ◽  
Zhi Min Tian
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Masonry Structure ◽  
Force Model ◽  
Restoring Force ◽  
Confined Masonry ◽  
Masonry Construction ◽  
State Education ◽  
Cold Area ◽  
Dynamic Time

Cavity walls structure is unsuitable in cold area for its faultiness of poor heat-insulating property. But the cavity walls constraint masonry construction is suitable in cold area for its high heat-insulating property. Studies are carried as setting up the restoring force model of the cavity walls confined masonry structure and analyzing the dynamic time-history of cavity walls constraint masonry structure under 7 degrees small earthquake, middle earthquake or large earthquake through EL centro wave, TALF wave, Ninghe wave and Qian'an wave, which indicates that cavity walls constraint masonry construction can satisfy seismic demand of 7 degree quake. Finally, the formula for calculating the interlayer displacement of cavity walls confined masonry structure near collapse is put forward and the counting result is compared with that of dynamic time-history analyzing, which shows that the accuracy of this formula is high enough to be used for analyzing the seismic performance of cavity walls constraint masonry structure. Foundation projects: Special Basic Scientific Research for Central Public Institute (2008B002, 2010A04), Open Fund of Key Laboratory of State Education Ministroy on Urben and Engineering Safe and Disaster Diminish & Key Laboratory of Beijing on Engineering Seismic and Treatment (EESR2010-07), and High Level Talent Support Project of Heilongjiang University (HDTD2010-13).

COMPARATIVE SEISMIC PERFORMANCE ASSESSMENT OF UHPC JACKETING AND SCED BRACING TECHNIQUES

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Roshen Joseph ◽  
Aman Mwafy ◽  
M. Shahria Alam
Keyword(s):  
Seismic Performance ◽  
High Performance ◽  
High Performance Concrete ◽  
Residential Building ◽  
Seismic Retrofit ◽  
Performance Criteria ◽  
Fragility Functions ◽  
Seismic Performance Assessment ◽  
Existing Building ◽  
Seismic Code

Observed damage to existing pre-seismic code buildings in previous earthquakes has raised interest among the engineering community for improving the performance of these structures using different seismic retrofit measures. This paper throws light on contemporary techniques for the seismic retrofit of RC buildings, namely ultra-high-performance concrete (UHPC) jacketing and self-centering energy dissipative (SCED) braces. Detailed fiber-based numerical modeling of a benchmark structure is undertaken to evaluate the effectiveness of the selected retrofit measures. The case study structure is a two-story pre-seismic code residential building designed for gravity and wind loads, exhibiting poor seismic performance. Along with the two retrofit strategies investigated, several parameters are also considered. Inelastic static pushover and incremental dynamic analyses are conducted to select the retrofit measures and assess their effects on seismic performance. Using a collection of far-field earthquake records and a set of performance criteria, fragility functions are constructed to assess the vulnerability of the benchmark structure with and without the retrofit solutions. The study shows that the adopted index that links cost to the seismic performance obtained from the fragility functions can provide a rational ranking of the selected retrofit approaches relative to the existing building and support selecting the most effective and economical alternative.

Multi-story truss moment frames equipped with friction dampers and self-centering system for enhanced seismic performance

2019 ◽  
Author(s):  
Keyhan Faraji ◽  
Robert Tremblay
Keyword(s):  
Seismic Performance ◽  
Structural Damage ◽  
Linear Time ◽  
Time History ◽  
Moment Frames ◽  
Moment Frame ◽  
Friction Energy ◽  
Hazard Level ◽  
Residual Deformations ◽  
Dynamic Time

<p>In this article, two new truss moment frame (TMF) systems exhibiting enhanced seismic performance are examined: truss moment frames with friction energy dissipation dampers between the truss bottom chord and the columns (F-TMFs) and F-TMFs with tendons added to achieve self-centering response (FT-TMFs). In both cases, all steel components of the systems are expected to behave essentially elastically to eliminate structural damage. The second system is also expected to have negligible residual lateral deformations. To compare and investigate the seismic performance of the proposed TMF systems, a 5-story commercial steel building located in Vancouver, BC, is designed in accordance with the National Building Code of Canada 2015 (NBCC) and it is subjected to a series of nonlinear static and dynamic time history analyses. The earthquake records, employed in non-linear time history analyses, are scaled for a hazard level corresponding to a probability of 2% in 50 years. The analytical results show that structural damage does not occur in neither of the two proposed systems . Meanwhile, FT-TMF system showed notably better seismic response and negligible residual deformations due to its self-centering capacity provided by the tendons.</p>

scholarly journals Enhancing the Seismic Performance of Precast RC Frames with Cladding Panels through Setting U-Shaped Dampers and Rocking Walls

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Qing Jiang ◽  
Hanqin Wang ◽  
Yulong Feng ◽  
Xun Chong ◽  
Junqi Huang ◽  
...  
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Seismic Energy ◽  
Structural Deformation ◽  
Relative Deformation ◽  
Rc Frames ◽  
Steel Bar ◽  
Cladding Panels ◽  
Dynamic Time ◽  
Rocking Walls

An approach combining U-shaped dampers (USDs) and rocking walls is proposed in this paper to improve the seismic performance of traditional precast reinforced concrete (RC) frames with cladding panels (PRCFCPs): (1) the steel bar and USD connection methods are adopted at the top and bottom of the cladding panels to use the relative deformation between the cladding panels and the main structure and then dissipate the seismic energy and (2) rocking walls are added to the structure to control the structural deformation profiles. The USD numerical model is calibrated using the test data, and a series of nonlinear pushover analyses, dynamic time-history analyses, and incremental dynamic analyses are successively performed to compare the seismic performance and collapse capacity of the PRCFCP, PRCFCP with USDs (PRCFCP-USD), and PRCFCP with USDs and rocking walls (PRCFCP-USD-RW).The results show that the USDs in the PRCFCP-USD-RW undergo more uniform deformation along the structural height and higher energy dissipation efficiency and the PRCFCP-USD-RW exhibits enhanced seismic performance and collapse capacity, which verify the superiority of the proposed combined approach.

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