scholarly journals Characterization of local and global capacity criteria for collapse assessment of code-conforming RC buildings

2021 ◽  
Author(s):  
Danilo D’Angela ◽  
Gennaro Magliulo ◽  
Francesca Celano ◽  
Edoardo Cosenza
Keyword(s):  
Earthquake Engineering ◽  
Fragility Curves ◽  
Eurocode 8 ◽  
Building Collapse ◽  
Frame Buildings ◽  
Rc Frame Buildings ◽  
Performance Based Earthquake Engineering ◽  
Collapse Assessment ◽  
Global Capacity

AbstractThe paper investigates both local and global capacity criteria for collapse assessment of RC frame buildings. Both literature and regulations criteria are considered, also including the formulation recommended in the draft of the new Eurocode 8 (part 3) and other collapse criteria never investigated. The case studies consist of low-rise bare and infilled frame buildings, which are designed according to the Italian code provisions considering low-to-high seismicity sites in Italy. The seismic demand is estimated by performing multiple-stripe analysis based on inelastic modeling, also including the presence of the infills. The capacity assessment and the performance evaluation associated with the (building) collapse are carried out according to the latest approaches and methodologies of performance-based earthquake engineering. The investigated capacity criteria are characterized as a result of the collapse assessment in terms of (a) collapse demand to capacity ratios, (b) collapse fragility curves, (c) collapse margin ratios and probabilities, and (d) inter-capacity margin ratios. The findings provide novel information and technical insights into the influence of the collapse capacity criteria selection on the collapse features of the investigated buildings. In particular, the capacity criteria are quantitatively correlated to the building collapse performance, also outlining safety and economic considerations.

scholarly journals Performance of RC frames in 26.11.2019. Albania earthquake: Effects of irregularities and detailing

2021 ◽  
Vol 64 (3) ◽  
pp. 207-213
Author(s):  
Ivan Milićević ◽  
Marko Marinković ◽  
Nikola Blagojević ◽  
Svetlana Nikolić-Brzev
Keyword(s):  
Earthquake Engineering ◽  
Rc Frame ◽  
Flexible Systems ◽  
Rc Frames ◽  
Seismic Force ◽  
Frame Buildings ◽  
Frame System ◽  
Rc Frame Buildings ◽  
Earthquake Effects ◽  
Global And Local

The collapse and damage of large number of buildings during the November 26, 2019 (Mw 6,4) Albania earthquake caused 51 fatalities and injuries to at least 910 people. Most of collapsed or heavily damaged buildings were RC frame buildings. Although RC frame system is considered as very ductile seismic force-resisting system, its behaviour during earthquake highly depends on: (1) regularity in plan and elevation, and (2) global and local ductility. Based on the authors' visit to the earthquake-affected area on behalf of the Serbian Association of Earthquake Engineering and observations of collapsed and damaged buildings, it was concluded that among main reasons for underperformance of these flexible systems were inadequate analysis of interaction between infill walls and RC frames and reinforcement detailing of RC members.

Discussion of “A Framework to Evaluate the Benefit of Seismic Upgrading”

2019 ◽  
Vol 35 (3) ◽  
pp. 1511-1514
Author(s):  
Panagiotis Galanis ◽  
Marco Broccardo ◽  
Lukas Bodenmann ◽  
Božidar Stojadinović
Keyword(s):  
Earthquake Engineering ◽  
Existing Buildings ◽  
Seismic Evaluation ◽  
Engineering Research ◽  
Existing Structures ◽  
The Pacific ◽  
The One ◽  
Performance Based Earthquake Engineering

Discussers (Michel et al.) address the paper “A Framework to Evaluate the Benefit of Seismic Upgrading” written by the coauthors of this response. Discussers present the compliance factor approach to evaluate existing structures and determine the need for a seismic upgrade implemented in the Swiss code SIA 269/8 and compare this approach to the one presented in the discussed paper. The approach proposed in the discussed paper combines elements of the Pacific Earthquake Engineering Research (PEER) Center Performance-Based Earthquake Engineering (PBEE) framework and the standard actuarial frequency-severity approach. Discussers criticize this approach as not being risk based and, consequently, consider it inappropriate for seismic evaluation of existing buildings. Coauthors welcome the comparison of different approaches for evaluation of existing buildings but disagree with the discussers’ characterization of the PEER PBEE framework and, by extension, the approach of the discussed paper.

scholarly journals Analytical simulation of seismic collapse of RC frame buildings

2015 ◽  
Vol 48 (3) ◽  
pp. 157-169 ◽  
Author(s):  
Mohammad E. Koopaee ◽  
Rajesh P. Dhakal ◽  
Gregory MacRae
Keyword(s):  
Rc Frame ◽  
Structural Components ◽  
Axial Loads ◽  
Building Collapse ◽  
Analytical Simulation ◽  
Frame Buildings ◽  
Load Carrying ◽  
Seismic Collapse ◽  
Rc Frame Buildings ◽  
Lumped Plasticity

Application of a fibre-element nonlinear modelling technique for seismic collapse capacity assessment of RC frame buildings in comparison with conventional lumped plasticity models is investigated in this paper. Constitutive material models of concrete and steel for fibre elements are adopted to enable simulation of the loss in vertical load carrying capacity of structural columns. Inclusion of the nonlinear second order P−Δ effects accelerated by degrading behaviour of steel and concrete materials in the fibre model allows prediction of the sidesway mode of collapse. The model is compared with nonlinear lumped plasticity models in which stiffness and strength degradation is replicated through degrading parameters in structural components. Static cyclic analyses of an example cantilever column and a portal frame indicate that the variation of axial loads in columns may result in accelerated degradation and failure of structural components which is not taken into account by lumped plasticity models. Moreover, incremental dynamic analysis of a ten-storey RC frame shows that the lumped plasticity model may overestimate building collapse capacity when vertical failure of structural components occurs prior to sidesway instability.

Probabilistic Seismic Response of Coupled Tank-Piping Systems

2016 ◽  
Author(s):  
Giuseppe Abbiati ◽  
Oreste S. Bursi ◽  
Luca Caracoglia ◽  
Rocco Di Filippo ◽  
Vincenzo La Salandra
Keyword(s):  
Earthquake Engineering ◽  
Fragility Curves ◽  
Coupled Systems ◽  
Piping System ◽  
Actual Behavior ◽  
Limit States ◽  
Industrial Plants ◽  
Stochastic Linearization ◽  
Piping Systems ◽  
Performance Based Earthquake Engineering

Dynamic analysis is an integral part of seismic risk assessment of industrial plants. Such analysis often neglects proper coupling between structures of coupled systems, which introduces uncertainty into the system and may lead to erroneous results, e.g., incorrect fragility curves, in comparison with the actual behavior of the analyzed structure. Hence, it is important to study the effect of uncertainties on the dynamic characteristics of a system, when coupling effects are both neglected and included. Along this line, this paper intends to define and compare the fragility curves of both an isolated (decoupled) and a coupled tank-piping system subjected to seismic loading. In particular, for the decoupled case, we estimated the probability of exceedance of main engineering demand parameters within the Performance-Based Earthquake Engineering (PBEE) framework. Moreover, for the coupled case, to take into account the presence of the tank as boundary condition for the piping system, two sources of uncertainty were considered: i) the tank aspect ratio; ii) the piping-to-tank attachment height ratio. In addition, to model the tank slippage, both a Filtered White Noise (FWN) characterized by a Kanai-Tajimi spectrum and the non-stationarity of the seismic input were taken into account by means of the stochastic linearization. All these elements allow for the estimation of fragility curves for different limit states in the coupled case.

Practitioner-friendly design method to improve the seismic performance of RC frame buildings

2021 ◽  
pp. 875529302098801
Author(s):  
Orlando Arroyo ◽  
Abbie Liel ◽  
Sergio Gutiérrez
Keyword(s):  
Seismic Performance ◽  
Design Method ◽  
Three Dimensional ◽  
Rc Frame ◽  
Structural System ◽  
Standard Code ◽  
Frame Buildings ◽  
Rc Frame Buildings ◽  
Mathematical Justification ◽  
Story Building

Reinforced concrete (RC) frame buildings are a widely used structural system around the world. These buildings are customarily designed through standard code-based procedures, which are well-suited to the workflow of design offices. However, these procedures typically do not aim for or achieve seismic performance higher than code minimum objectives. This article proposes a practical design method that improves the seismic performance of bare RC frame buildings, using only information available from elastic structural analysis conducted in standard code-based design. Four buildings were designed using the proposed method and the prescriptive approach of design codes, and their seismic performance is evaluated using three-dimensional nonlinear (fiber) models. The findings show that the seismic performance is improved with the proposed method, with reductions in the collapse fragility, higher deformation capacity, and greater overstrength. Furthermore, an economic analysis for a six-story building shows that these improvements come with only a 2% increase in the material bill, suggesting that the proposed method is compatible with current project budgets as well as design workflow. The authors also provide mathematical justification of the method.

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