scholarly journals Development of Analytical Seismic Fragility Functions For The Common Buildings In Iran

2021 ◽  
Author(s):  
Zarrin Karimzadeh ◽  
Mohsen Ghafory-Ashtiany ◽  
Afshin Kalantari ◽  
Sahar Shokuhirad
Keyword(s):  
Seismic Risk ◽  
Linear Time ◽  
Construction Materials ◽  
Time History ◽  
Seismic Fragility ◽  
Large Set ◽  
Fragility Functions ◽  
Backbone Curve ◽  
Existing Building ◽  
The Common

Abstract One of the main components for the development of regional seismic risk models is the fragility functions for common building types. Due to the differences between the national design codes, construction practices, and construction materials, it is necessary to develop specific fragility functions for the common building types which are constructed in each region. One of the existing challenges is the lack of classified, reliable, and cogent local seismic fragility functions for common buildings in Iran. For this reason, the present study is devoted to filling this essential gap. Therefore, at the first step, a comprehensive study was performed on the existing building types in the country. Finally, the Iranian common buildings are classified into 35 categories regarding material, lateral-load-resisting system, age, height, and code level. Also, by conducting comprehensive studies on all previously performed researches in the country, structural and dynamic parameters have been collected for buildings in each class. This information was used to compute a large set of backbone curves for Iranian buildings taxonomy. In the next steps, a large set of ground motion records were selected. Then non-linear time-history analyses were performed on the generic backbone curve for each type of building, and the structural responses were used to derive fragility functions for building classes. Then nearly three hundred appropriate fragility functions were generated for Iranian common buildings considering both record-to-record and building-to-building response variability using cloud analysis. Based on the existing empirical data from past earthquakes in the country, the validation of the resulting fragility functions was carried out. The resulted fragility functions can be utilized in seismic risk assessment studies in the country.

scholarly journals Fragility Analysis and Risk Assessment of Precast Concrete Frames with “Dry” Connections: A Comparative Study

2021 ◽  
Vol 1203 (3) ◽  
pp. 032045
Author(s):  
Chenhao Wu
Keyword(s):  
Energy Dissipation ◽  
Comparative Study ◽  
Seismic Risk ◽  
Social Impact ◽  
Precast Concrete ◽  
Time History ◽  
Fragility Functions ◽  
Concrete Frames ◽  
Energy Dissipation Devices

Abstract Precast concrete frames (PCFs) with "dry" connections and self-centering capacity have been proposed as a new kind of seismic protective structural system with characteristics of damage controllable mechanism, easy-assemblage and rapid repair speed. The damage mechanism of PCFs are concentrated at the panel zones under earthquake excitations, so as to avoid damage to beam and column components. Through reasonable design for the PCFs, not only the structural and life safeties can be guaranteed, but also the seismic loss and social impact can be minimized. This paper conducts a comparative study between PCFs with "dry" connections and conventional cast-in-situ concrete frame. A generalized beam-column connection analytical model is utilized to predict the seismic behaviour of PCFs with energy dissipation devices, with an emphasis on the opening behaviour at beam-column interfaces, the self-centering capacity provided by prestressed tendons and the hysteresis behaviour provided by energy dissipation devices. Prototype PCFs or cast in situ frame structures are designed to achieve similar deformation capacities in Chinese highly seismic fortification zone. Probabilistic seismic capacity analyses (PSCA) are conducted based on the results of probabilistic pushover analyses and Latin Hypercube Sampling. Incremental dynamic analysis method combined with nonlinear time history analyses are utilized to conduct probabilistic seismic demand analyses (PSDA). Fragility functions of different structural systems are derived based on the convolution of PSCA and PSDA. Finally, the seismic risk is evaluated based on the fragility functions and the developed Chinese seismic code compliant hazard functions. The results indicate that PCFs with energy dissipation devices can have lower seismic risk than conventional cast-in-site frames.

Comparison of Interstorey Drift in General RC Buildings in Pounding and No Pounding Case

2020 ◽  
Vol 2 (1) ◽  
pp. 40-47
Author(s):  
Anand Dev Bhatt
Keyword(s):  
Seismic Analysis ◽  
Linear Time ◽  
Time History ◽  
Case Analysis ◽  
Rc Buildings ◽  
Adjacent Buildings ◽  
Sufficient Distance ◽  
Earthquake Load ◽  
Interstorey Drift ◽  
Lower Height

 Inter-storey drift is an important parameter of structural behavior in seismic analysis of buildings. Pounding effect in building simply means collision between adjacent buildings due to earthquake load caused by out of phase vibration of adjacent buildings. There is variation in inter-storey drift of adjacent buildings during pounding case and no pounding case. The main objective of this research was to compare the inter-storey drift of general adjacent RC buildings in pounding and no pounding case. For this study two adjacent RC buildings having same number of stories have been considered. For pounding case analysis there is no gap in between adjacent buildings and for no pounding case analysis there is sufficient distance between adjacent buildings. The model consists of adjacent buildings having 4 and 4 stories but unequal storey height. Both the buildings have same material & sectional properties. Fast non-linear time history analysis was performed by using El-centro earthquake data as ground motion. Adjacent buildings having different overall height were modelled in SAP 2000 v 15 using gap element for pounding case. Finally, analysis was done and inter-storey drift was compared. It was found that in higher building inter-storey drift is greater in no pounding case than in pounding case but in adjacent lower height building the result was reversed. Additionally, it was found that in general residential RC buildings maximum inter-storey drift occurs in 2nd floor.

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.

scholarly journals Tuned Mass Damper Design for Slender Masonry Structures: A Framework for Linear and Nonlinear Analysis

2021 ◽  
Vol 11 (8) ◽  
pp. 3425
Author(s):  
Marco Zucca ◽  
Nicola Longarini ◽  
Marco Simoncelli ◽  
Aly Mousaad Aly
Keyword(s):  
Nonlinear Analysis ◽  
Linear Time ◽  
Design Procedure ◽  
Time History ◽  
Tuned Mass Damper ◽  
Second Phase ◽  
Masonry Structures ◽  
Base Shear ◽  
Mass Damper ◽  
Linear And Nonlinear

The paper presents a proposed framework to optimize the tuned mass damper (TMD) design, useful for seismic improvement of slender masonry structures. A historical masonry chimney located in northern Italy was considered to illustrate the proposed TMD design procedure and to evaluate the seismic performance of the system. The optimization process was subdivided into two fundamental phases. In the first phase, the main TMD parameters were defined starting from the dynamic behavior of the chimney by finite element modeling (FEM). A series of linear time-history analyses were carried out to point out the structural improvements in terms of top displacement, base shear, and bending moment. In the second phase, masonry's nonlinear behavior was considered, and a fiber model of the chimney was implemented. Pushover analyses were performed to obtain the capacity curve of the structure and to evaluate the performance of the TMD. The results of the linear and nonlinear analysis reveal the effectiveness of the proposed TMD design procedure for slender masonry structures.

scholarly journals Displacement-based design of precast hinged portal frames with additional dissipating devices at beam-to-column joints

2021 ◽  
Author(s):  
Andrea Belleri ◽  
Simone Labò
Keyword(s):  
Design Methodology ◽  
Linear Time ◽  
Design Procedure ◽  
Time History ◽  
Structural System ◽  
Additional Degree ◽  
Speed Up ◽  
Column Joint ◽  
Displacement Based ◽  
Mechanical Devices

AbstractThe seismic performance of precast portal frames typical of the industrial and commercial sector could be generally improved by providing additional mechanical devices at the beam-to-column joint. Such devices could provide an additional degree of fixity and energy dissipation in a joint generally characterized by a dry hinged connection, adopted to speed-up the construction phase. Another advantage of placing additional devices at the beam-to-column joint is the possibility to act as a fuse, concentrating the seismic damage on few sacrificial and replaceable elements. A procedure to design precast portal frames adopting additional devices is provided herein. The procedure moves from the Displacement-Based Design methodology proposed by M.J.N. Priestley, and it is applicable for both the design of new structures and the retrofit of existing ones. After the derivation of the required analytical formulations, the procedure is applied to select the additional devices for a new and an existing structural system. The validation through non-linear time history analyses allows to highlight the advantages and drawbacks of the considered devices and to prove the effectiveness of the proposed design procedure.

scholarly journals Implementation of BIM Modelling and Simulation Tools in Reducing Annual Energy Consumption of Multifamily Dwellings

2020 ◽  
Vol 170 ◽  
pp. 01002
Author(s):  
Subbarao Yarramsetty ◽  
MVN Siva Kumar ◽  
P Anand Raj
Keyword(s):  
Energy Efficient ◽  
Energy Use ◽  
Construction Materials ◽  
Residential Building ◽  
Energy Simulation ◽  
Point Of View ◽  
Rotational Angle ◽  
Existing Building ◽  
Simulation Tools ◽  
Efficient Option

In current research, building modelling and energy simulation tools were used to analyse and estimate the energy use of dwellings in order to reduce the annual energy use in multifamily dwellings. A three-story residential building located in Kabul city was modelled in Revit and all required parameters for running energy simulation were set. A Total of 126 experiments were conducted to estimate annual energy loads of the building. Different combinations from various components such as walls, roofs, floors, doors, and windows were created and simulated. Ultimately, the most energy efficient option in the context of Afghan dwellings was figured out. The building components consist of different locally available construction materials currently used in buildings in Afghanistan. Furthermore, the best energy efficient option was simulated by varying, building orientation in 15-degree increments and glazing area from 10% to 60% to find the most energy efficient combination. It was found that combination No. 48 was best option from energy conservation point of view and 120-degree rotational angle from north to east, of the existing building was the most energy-efficient option. Also, it was observed that 60% glazing area model consumed 24549 kWh more electricity compared to the one with 10% glazing area.

Excavations of Aztec Urban Houses at Yautepec, Mexico

1999 ◽  
Vol 10 (02) ◽  
pp. 133-150 ◽  
Author(s):  
Michael E. Smith ◽  
Cynthia Heath-Smith ◽  
Lisa Montiel
Keyword(s):  
Construction Materials ◽  
Large Set ◽  
Mexican State ◽  
Residential Structures ◽  
The Relationship ◽  
House Size

Our recent excavations at the site of Yautepec in the Mexican state of Morelos have uncovered a large set of residential structures from an Aztec city. We excavated seven houses with associated middens, as well as several middens without architecture. In this paper, we briefly review the excavations, describe each house, and summarize the nature of construction materials and methods employed. We compare the Yautepec houses with other known Aztec houses and make some preliminary inferences on the relationship between house size and wealth at the site.

Seismic Risk Evaluation of Retrofitted Reinforced Concrete Buildings Utilizing Base Isolation and Considering Mainshock-Aftershock

2013 ◽  
Vol 671-674 ◽  
pp. 1372-1375
Author(s):  
Rui Long Han ◽  
Yue Li
Keyword(s):  
Seismic Risk ◽  
Risk Evaluation ◽  
Base Isolation ◽  
Seismic Hazards ◽  
Nonlinear Finite Element ◽  
Structural Safety ◽  
Seismic Fragility ◽  
Rc Frame ◽  
Actual Situation ◽  
Element Analysis

The insufficient consideration of seismic risk caused hidden danger for structural safety in many areas. A promising retrofit method for these structures is base isolation. In order to evaluate the effectiveness of this approach, a hypothetical RC frame based on actual situation is designed to be retrofitted using base isolation. Then, seismic fragilities for both un-retrofitted and isolated frames are analyzed, utilizing the results obtained from nonlinear finite-element analysis. The ground motion of the analysis contains 22 earthquake motions, and the results of considering mainshock-aftershock and those of considering only mainshock are compared. The study proves the well designed base isolation can reduce the seismic fragility of the RC frame effectively, and the exclusive consideration of mainshock will underestimate the seismic hazards for structures.

Enhancing the application potential of dissipative controlled rocking connections through detailing and design

2021 ◽  
Author(s):  
Brandon McHaffie ◽  
Peter Routledge ◽  
Alessandro Palermo
Keyword(s):  
Linear Time ◽  
Time History ◽  
Cost Effective ◽  
Real Structure ◽  
Construction Costs ◽  
Alternative Design ◽  
Design Philosophy ◽  
History Analysis ◽  
Application Potential ◽  
The University

<p>Research on low-damage systems has been significant in the past decade. These systems combine post- tensioning, which provides self-centring; and typically use replaceable devices, which give energy dissipation. WSP has used recent research, carried out at the University of Canterbury, on low-damage bridge piers and applied this into a real structure – the Wigram-Magdala Link Bridge. This is believed to be the first bridge in New Zealand and possibly worldwide to adopt such a system. Given this was the first application of the system to a real structure, there were some valuable learnings during design and construction. Firstly, the application of axial dissipaters has some limitations due to available material sizes, construction difficulty and aesthetics. Secondly, there is still some additional cost and complexity associated with using the low-damage system. Given these difficulties, this paper presents an alternative design philosophy which better captures the benefits of the low-damage system, which include cost-effective repair method, controlled damage and additional robustness and resilience. The alternative design philosophy presented is expected to result in reduced construction costs by reducing pier and foundation demands. Peak displacements and forces will be compared to the results from non-linear time history analysis to verify the performance of the low-damage connection using scaled ground motions. Furthermore, the paper will present the possible application of an alternative dissipation device, the lead extrusion damper, which can further improve the performance of low-damage connections.</p>

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