scholarly journals Effect of Buoyancy Loads on the Tsunami Fragility of Reinforced Concrete Frames Including Consideration of Blow-out Slabs

2021 ◽  
Author(s):  
Marta Del Zoppo ◽  
Tiziana Rossetto ◽  
Marco Di Ludovico ◽  
Andrea Prota
Keyword(s):  
Reinforced Concrete ◽  
Damage Evolution ◽  
Structural Damage ◽  
Shear Failure ◽  
Fragility Curves ◽  
Indirect Costs ◽  
Concrete Frames ◽  
Rc Frames ◽  
Tsunami Fragility

Abstract Currently available performance-based methodologies for assessing the fragility of structures subjected to tsunami neglect the effects of tsunami-induced vertical loads due to internal buoyancy. This paper adopts a generalized methodology for the performance assessment of structures that integrates the effects of buoyancy loads on slabs during a tsunami inundation. The methodology is applied in the fragility assessment of three case-study frames (low, mid and high-rise), representative of existing masonry-infilled reinforced concrete (RC) buildings typical of Mediterranean region. The paper shows the effect of modelling buoyancy loads on damage evolution, structural performance and fragility curves associated with different structural damage mechanisms for RC frames with breakaway infill walls including consideration of blow-out slabs. The outcomes attest that the predominant failure mechanism of selected case-study is the brittle shear failure of seaward columns, which is slightly affected by buoyancy loads. When brittle failure is avoided, buoyancy loads significantly affect the damage evolution during a tsunami, especially in the case of structures with blow-out slabs. The rate of occurrence of slabs uplift failure increases with the number of stories of the building but only slightly affects the fragility curves of investigated structures. However, it can significantly increase their vulnerability, affecting both direct and indirect costs deriving from the repair of the damaged interior slabs.

scholarly journals Strength and ductility in reinforced concrete frames designed with Mexican codes

1990 ◽  
Vol 23 (3) ◽  
pp. 184-197 ◽  
Author(s):  
M. Rodriguez
Keyword(s):  
Reinforced Concrete ◽  
Structural Damage ◽  
Analytical Models ◽  
Reinforcing Steel ◽  
Concrete Frames ◽  
Approximate Methods ◽  
Reinforced Concrete Frames ◽  
Rc Frames ◽  
Mexico Earthquake ◽  
Strength And Ductility

The strength and ductility capacities of several structural sections of members in typical reinforced concrete frames designed with Mexican Codes are calculated using analytical models for confined concrete and reinforcing steel. These ductility capacities are associated with global displacement ductilities in the RC frames using approximate methods of analysis described in this paper. Results obtained in this investigation are correlated with typical pattern of structural damage in RC frames observed during the 1985 Mexico Earthquake. Some aspects of the seismic performance of fully ductile frames designed according to the 1987 Mexico City Building Code are also discussed, as well as the effect of some mechanical properties of reinforcing steel on the strength and ductility of RC frames.

Seismic Vulnerability Analysis of Reinforced Concrete Frames with Mild Steel Dampers

2011 ◽  
Vol 368-373 ◽  
pp. 1526-1530 ◽  
Author(s):  
Jian Zhu ◽  
Ping Tan
Keyword(s):  
Reinforced Concrete ◽  
Mild Steel ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Response Spectrum ◽  
Time History ◽  
Concrete Frames ◽  
Rc Frames ◽  
History Analysis ◽  
Reduction Effect

This study focus on derivation of such fragility curves using conventional old reinforced concrete (RC) frames with Mild Steel Damper (MSD) of flexural energy dissipation braces. A set of stochastic earthquake waves compatible with the response spectrum of China seismic code selected to represent the variability in ground motion. Dynamic inelastic time history analysis was used to analyze the random sample of structures. Weak position was be pointed out, The result reveal that excellent reduction effect for structure of MSD is favorable and obvious under major earthquake.

Progressive Collapse Analysis of Reinforced Concrete Frames with Unreinforced Masonry Infill Walls considering In-Plane/Out-of-Plane Interaction

2015 ◽  
Vol 31 (2) ◽  
pp. 921-943 ◽  
Author(s):  
Khalid M. Mosalam ◽  
Selim Günay
Keyword(s):  
Reinforced Concrete ◽  
Shear Failure ◽  
Progressive Collapse ◽  
Unreinforced Masonry ◽  
Concrete Frames ◽  
Infill Wall ◽  
Infill Walls ◽  
Rc Frames ◽  
Out Of Plane ◽  
Plane Interaction

Reinforced concrete (RC) frames with unreinforced masonry (URM) infill walls are commonly used in seismic regions around the world. It is recognized that many buildings of this type perform poorly during earthquakes. Therefore, proper modeling of the infill walls and their effect on RC frames is essential to evaluate the seismic performance of such buildings and to select adequate retrofit methods. Using damage observations of RC buildings with URM infill walls from recent earthquakes, this paper presents a new approach to consider in-plane/out-of-plane interaction of URM infill walls in progressive collapse simulations. In addition, the infill wall effect to induce shear failure of columns is simulated with a nonlinear shear spring modeling approach. The research endeavor is accompanied by implementation of the developed modeling aspects in the publicly available open-source computational platform OpenSees for immediate access by structural engineers and researchers.

Behavior Study of High Impact Resistant Reinforced Concrete Frames Using Crack Conduction Method

2006 ◽  
Author(s):  
Navid Heidarzadeh ◽  
S. Mohammad Razavi ◽  
Nima Shamsaei
Keyword(s):  
Reinforced Concrete ◽  
Impact Loading ◽  
Failure Modes ◽  
Side Surface ◽  
High Impact ◽  
Structural Behavior ◽  
Concrete Frames ◽  
Rc Frames ◽  
Behavior Study ◽  
Falling Weight

In this study, the influence of crack conduction method on behavior of reinforced concrete (RC) frame under iterative high impact loading were experimented. To investigate the structural behavior through large deformations and progressive damage and to identify the failure modes, the falling weight and falling height were set more than the structural strength in elastic state. A comprehensive scheme which indicated influence of location of initial cracks on behavior and failure mode of structure was developed. Falling weight impact test was conducted on twenty-one laboratory scaled RC frames which were categorized in four series regard to considered scheme. Concrete volume and compressive strength, number of longitudinal and transverse rebar were constant factors in all specimens. Deformed shape and crack patterns, developed on the side surface of the RC frames, were sketched and total deflections vs. cumulative input energy of the RC girder were plotted. The results revealed the influence of crack conduction on improving the structural behavior and extending the endurance of RC frames against iterative high impact loading.

scholarly journals The Effect of Mechanical and Geometric Parameters on the Shear and Axial Failures of Columns in Reinforced Concrete Frames

2015 ◽  
Vol 37 ◽  
pp. 247 ◽  
Author(s):  
Hooman Farahmand ◽  
Mohammad Reza Azadi Kakavand ◽  
Shahriar Tavousi Tafreshi ◽  
Pooria Hafiz Hafiz
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Shear Failure ◽  
Load Ratio ◽  
Analytical Models ◽  
Transverse Reinforcement ◽  
Effective Parameters ◽  
Concrete Frames ◽  
Research Activities ◽  
Axial Load Ratio

Experimental research activities and post-earthquake considerations have demonstrated that reinforcedconcrete columns with light or widely spaced transverse reinforcement are vulnerable to shear failure duringearthquakes. According to this point by using failure limit curve, we can assess the effective parameters in shearand axial failure of reinforced concrete columns in framed buildings. In the current study by flexural, shear andaxial springs which are used in series, shear and axial failures and important effective parameters have beenassessed, Besides 5,10 and 15 story models with different amounts of initial axial load ratio have been analyzedby nonlinear push-over analysis. The results of analytical models contain behavior of buildings based on differentinitial axial load ratio and different spacing of transverse reinforcement are compared

Ductility Reduction Factors for Masonry-Infilled Reinforced Concrete Frames

2015 ◽  
Vol 31 (1) ◽  
pp. 339-365 ◽  
Author(s):  
Manish Kumar ◽  
Durgesh C. Rai ◽  
Sudhir K. Jain
Keyword(s):  
Reinforced Concrete ◽  
Traditional Approach ◽  
Statistical Tests ◽  
Experimental Studies ◽  
Reduction Factor ◽  
Model Parameters ◽  
Deformation Model ◽  
Concrete Frames ◽  
Ductility Demand ◽  
Rc Frames

Masonry-infilled reinforced concrete (RC) frames are popular structural systems; however, there is much uncertainty in their response under seismic loads. Using the data from past experimental studies, a simple force-deformation model with three control points was developed. The effect of the model parameters on the ductility reduction factor (DRF) and ductility demand (DD) was examined. Statistical tests indicated that the ratio of residual strength to peak strength was the most significant parameter. The traditional approach to determining DRF ordinates through iteration for an assumed value of ductility may result in inappropriate DRF values because of the nonmonotonic relationship between DRF and DD. Constant ductility charts were developed to appropriately account for nonmonotonicity. It was found that the allowable DRF may be much higher if relatively weaker infill compared to the strength of the frame is used, which underscores the need for modifying code provisions because they allow relatively strong infill.

Vulnerability Index of Algiers Reinforced Concrete Buildings

2013 ◽  
Vol 685 ◽  
pp. 228-232
Author(s):  
Farah Lazzali ◽  
Mohamed N. Farsi
Keyword(s):  
Reinforced Concrete ◽  
Structural Damage ◽  
Seismic Vulnerability ◽  
Shear Failure ◽  
Construction Materials ◽  
Vulnerability Index ◽  
Design Parameters ◽  
Structural System ◽  
Damage Indicator

Reinforced Concrete (R/C) buildings experienced major damage in past earthquakes. Structural damage including column cracking, shear failure and collapse, were due to particular conditions, such as: poor member sizing and detailing, soft stories, building irregularity, bounding, bad quality of construction materials and workmanship. Various approaches and methods to assess the seismic vulnerability of buildings were established through examining a damage indicator: “vulnerability index”. In this work, a simplified vulnerability index based on design parameters describing the deficiencies of the structural system is proposed. The global index of each R/C building in the surveyed area is evaluated and normalized.

scholarly journals Effect of Different Bracing Systems in Reinforced Concrete Frames under Cyclic Loading

2020 ◽  
Vol 9 (7) ◽  
pp. 704-708
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Structural Parameters ◽  
Rc Frame ◽  
Concrete Frames ◽  
Element Analysis ◽  
Framed Structures ◽  
Rc Frames ◽  
Seismic Force ◽  
Rc Framed Structures

Reinforced concrete (RC) framed structures are widely used as load transferring system in residential and commercial buildings. Even though the RC frames are designed for gravitational and seismic forces, but they are week under severe seismic events. The main disadvantage of the framed structures is inefficient bracing systems designed in it. This investigation is conducted mainly to study the effective bracing system in the RC framed structure to transfer the seismic force. This research aims to study the seismic performance of RC frames influenced by the various types of cross bracings under cyclic loading. The finite element analysis software package ABAQUS is used to investigate the braced RC frames analytically. The research scheme consists of three RC frames; the bare frame, the bare frame with single X-bracing (X frame), double X bracing (D-X frame) along the height. The structural parameters include, load-displacement hysteresis envelope, stiffness degradation and energy absorption were studied to analyze the performance of bracings. The results showed that the X frame and D-X frame noticeably increased the lateral strength, stiffness and energy dissipation properties compared to the bare RC frame. The results also indicated that the addition of X bracing along the height significantly enhanced the structural parameters of the RC frame.

scholarly journals Impact of Earthquake Types and Aftershocks on Loss Assessment of Non-Code-Conforming Buildings: Case Study with Victoria, British Columbia

2017 ◽  
Vol 33 (2) ◽  
pp. 551-579 ◽  
Author(s):  
Solomon Tesfamariam ◽  
Katsuichiro Goda
Keyword(s):  
British Columbia ◽  
Reinforced Concrete ◽  
Earthquake Engineering ◽  
Concrete Frames ◽  
Loss Assessment ◽  
Rc Frames ◽  
Annual Probability ◽  
Story Drift ◽  
Hysteretic Characteristics ◽  
The Impact

This paper presents a study on the impact of earthquake types (shallow crustal, deep inslab, and megathrust Cascadia interface earthquakes) and aftershocks on loss assessment of non-code-conforming reinforced concrete (RC) buildings. The loss assessment is formulated within the performance-based earthquake engineering framework. The dependency between the maximum and residual inter-story drift ratios are captured using copulas. Finite-element models that take into account key hysteretic characteristics of non-ductile RC frames were adopted and incremental dynamic analysis is utilized to compute collapse risk. The proposed procedure is applied to a set of 2-, 4-, 8-, and 12-story non-ductile reinforced concrete frames located in Victoria, British Columbia, Canada. From the results, the aftershock showed marked difference for the 2-story building. At annual probability of 10−2–10−3, crustal and inslab events with Mw6.5 to Mw7.5 contributed the most to the loss as these events occur more frequently. At rarer annual probability of 10−3–10−4, the Cascadia event having Mw8.5 to Mw9.0 is predominant and contributed the most to the loss.

Sign in / Sign up

Export Citation Format

Share Document