scholarly journals Damage-Based Seismic Retrofitting Approach for Nonductile Reinforced Concrete Structures Using FRP Composite Wraps

2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Vui Van Cao ◽  
Son Quang Pham
Keyword(s):  
Plastic Hinge ◽  
Seismic Damage ◽  
Seismic Retrofitting ◽  
Engineering Practice ◽  
Similar Amount ◽  
Building Structures ◽  
Frp Composite ◽  
Damage Indices ◽  
Fibre Reinforced Polymer ◽  
Critical Locations

Applying similar amount of fibre reinforced polymer (FRP) for all plastic hinge locations in a structure is not an ideal approach as damage occurring at these critical locations may vary considerably. Building owners also always want to keep FRP retrofitting cost and associated interruption to a minimum. In this context, the current paper proposes an FRP retrofitting approach, in which FRP is selectively distributed based on the distribution of seismic damage in structures. The proposed approach, characterized by both quantitative and qualitative criteria, is simple but very effective in simultaneously reducing the seismic damage, amount of FRP to be used, and time of installation. For the considered cases of low- and mid-rise nonductile building structures, the FRP amount reduced approximately by 31% compared to the cases in which FRP was evenly distributed, leading to lower installation cost and less interruption time. Interestingly, although 31% FRP was saved, the damage indices of the FRP retrofitted frames were significantly lower than those in cases of even FRP distribution because FRP effectively served for critical locations. Due to its simplicity and technical/economical effectiveness, the proposed FRP retrofitting approach can be useful for engineering practice.

scholarly journals Fibre Reinforced Polymer in Retrofitting

2021 ◽  
Vol 9 (12) ◽  
pp. 83-87
Author(s):  
Sumirah Nisar
Keyword(s):  
Construction Industry ◽  
Seismic Damage ◽  
Seismic Action ◽  
Existing Structures ◽  
Frp Composite ◽  
Current State ◽  
Reinforced Polymer ◽  
Earthquake Resistant ◽  
The World ◽  
Fibre Reinforced Polymer

Abstract: Retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion etc. Many of the existing reinforced concrete structures throughout the world are in urgent need of rehabilitation, repair or reconstruction because of deterioration due to various factors like corrosion, lack of detailing, failure of bonding between beamcolumn joints etc. Fibre Reinforced Polymer (FRP) composite has been accepted in the construction industry as a promising substitute for repairing and in incrementing the strength of RCC structures. It stabilizes the current structure of buildings and making them earthquake resistant. This paper presents a representative overview of the current state of using FRP materials as a retrofitting technique for the structures not designed to resist seismic action. It summarizes the scopes and uses of FRP materials in seismic strengthening of RCC structures and masonry retrofitting. Keywords: Retrofitting, Rehabilitation, Seismic damage, fibre

INVESTIGATION OF SEISMIC DAMAGE OF CABLE-STAYED BRIDGES WITH DIFFERENT CONNECTION CONFIGURATION

2009 ◽  
Vol 03 (03) ◽  
pp. 227-247 ◽  
Author(s):  
HUI LI ◽  
JINLONG LIU ◽  
JINPING OU
Keyword(s):  
Failure Modes ◽  
Plastic Hinge ◽  
Damage Index ◽  
Seismic Damage ◽  
Damage Indices ◽  
Floating System ◽  
Energy Dissipation System ◽  
Damage Condition ◽  
Seismic Behaviors ◽  
Cable Stayed Bridges

In this paper, the seismic behaviors of three cable-stayed bridges with different structural systems including Rigid System (RS), Floating System (FS) and Passive Energy Dissipation System (PEDS) are studied. The results show that the seismic behaviors of these bridges are so different even under the same earthquake. Based on damage analysis of the towers, failure modes of the three different systems are concluded. For RS, the bottom of the middle tower is a vulnerable region, implying that the failure mainly focuses here and plastic hinge forms under earthquake. The FS is damaged most severely, in which the edge tower has a larger damage index than that of middle tower. While the seismic responses of PEDS decrease dramatically compared to FS due to the incorporation of viscous dampers and the damage indices for all towers are small. The seismic damage condition between the middle tower and the edge tower can be adjusted by changing the damping coefficient of the viscous damper.

scholarly journals Mitigating natural events to avoid disaster in public school buildings: seismic retrofitting of SDN 42 Korong Gadang

2018 ◽  
Vol 229 ◽  
pp. 02021
Author(s):  
James Mwangi ◽  
Laura Putri ◽  
Listhbeth Collins
Keyword(s):  
School Facilities ◽  
Seismic Retrofitting ◽  
Building Structures ◽  
National Agency ◽  
Electrical Grid ◽  
The North ◽  
Australian Plate ◽  
West Sumatra

With over 50 million students, Indonesia has the fourth largest education system in the world. The first twelve years of education are compulsory for all citizens. The students, together with over 3 million teachers spend six (or five in some cases) days a week at over 300,000 schools, typically from 6:30 AM to 2 (or 3) PM. Geographically, Indonesia is traversed by the infamous “ring of fire” and prone to natural events resulting from the tectonic plate movements of the Australian Plate from the South, the Eurasian and Sunda Plates from the North and the Philippine Plate from the East. Left unmitigated, these natural events would lead to natural disasters emanating from resulting earthquakes and leading to tsunamis, landslides, the collapse of building structures and failure of lifelines (roads, pipelines, electrical grid, etc.). In an effort to provide disaster-safe schools, the National Agency for Disaster Management has required that school facilities be a community center in case of disasters and serve as emergency shelters. Retrofit of existing buildings will be needed to comply with government guidelines. This paper presents a case study of the determination of structural deficiencies of an existing school building in SDN 42 Korong Gadang, Padang, West Sumatra and implementation of a seismic retrofit (design and construction) at the same building to mitigate potential earthquake disaster.

Seismic Damage Analysis on the Continuous Girder Bridge of Urban Rail Transit Line

2014 ◽  
Vol 488-489 ◽  
pp. 398-402 ◽  
Author(s):  
Hai Qing Li ◽  
Yong Jun Ni ◽  
Xin Gang Liu ◽  
Jin Xing Yan
Keyword(s):  
Seismic Performance ◽  
Evaluation Method ◽  
Research Direction ◽  
Seismic Damage ◽  
Urban Rail Transit ◽  
Rail Transit ◽  
Damage Analysis ◽  
Seismic Performance Evaluation ◽  
Damage Indices ◽  
Urban Rail

Seismic damage was the key reason which resulted in the serviceability degradation or collapse of the bridge. How to quantify the seismic damage and evaluate the seismic performance of the bridge under earthquakes through the damage analysis was the significant research direction in the performance based seismic design. In this paper the Park-Ang model (a well-known dual parameters model) and its modification version used for the damage evaluation of the concrete structure were compared. Furthermore, through the definition of the damage indices of the models based on the modified Park-Ang model and the descending slope of the IDA(incremental dynamic analysis) curve, the seismic damage levels of the typical bridge in the urban rail transit line under the designated earthquakes were analyzed, respectively. It was shown from the results that the calculated results from the two model was essentially consistent. The damage analysis based evaluation method was feasibly used for the seismic performance evaluation of the bridge.

The all-composite road bridge – a proposal for rapid urbanisation

2018 ◽  
Author(s):  
Tomasz Siwowski ◽  
Aleksander Kozlowski ◽  
Leonard Ziemiański ◽  
Mateusz Rajchel ◽  
Damian Kaleta
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Construction Materials ◽  
Fast Growing ◽  
Frp Composites ◽  
Frp Composite ◽  
Reinforced Polymer ◽  
Composite Bridge ◽  
Fibre Reinforced Polymer ◽  
Traditional Construction

<p>Technology and materials can help cities get smarter and cope with rapid urbanisation. Life cycle assessment (LCA) is one of the approaches applied in evaluation of material sustainability. Many significant LCA comparisons of innovative and traditional construction materials indicate that fibre- reinforced polymer (FRP) composites compare very favourably with other materials studied. As a proposal for rapid urbanisation, the FRP all-composite road bridge was developed and demonstrated in Poland. The paper describes the bridge system itself and presents the results of research on its development. The output of the R&amp;D project gives a very promising future for the FRP composite bridge application in Poland, especially for cleaner, resilient and more environmentally efficient infrastructure of fast-growing cities.</p>

Failure Mechanism of Reinforced Concrete Rib Arch Bridge under Near-Fault Earthquakes

2011 ◽  
Vol 90-93 ◽  
pp. 940-945
Author(s):  
Wen Jun Gao ◽  
Guang Wu Tang ◽  
Yi Da Kong
Keyword(s):  
Reinforced Concrete ◽  
Nonlinear Response ◽  
Plastic Hinge ◽  
Seismic Damage ◽  
Arch Bridge ◽  
2008 Wenchuan Earthquake ◽  
Near Fault ◽  
Pulse Type ◽  
Near Fault Earthquakes ◽  
Far Fault

A typical reinforced concrete rib arch bridge was chosen to investigate its nonlinear response to near-fault ground motions recorded in 2008 Wenchuan earthquake. Results showed that significant seismic damage may occur, maximum demands were higher for near-fault records having forward directive than far-fault motions, and the rotational capacity of rib plastic hinge is not enough for the large compression force of arch rib. While backward-directivity motions, typically do not exhibit pulse-type motions, only have medium seismic damage to the arch bridge.

scholarly journals Hybrid backpropagation neural network-particle swarm optimization for seismic damage building prediction

2019 ◽  
Vol 14 (1) ◽  
pp. 360
Author(s):  
Marina Yusoff ◽  
Faris Mohd Najib ◽  
Rozaina Ismail
Keyword(s):  
Neural Network ◽  
Particle Swarm Optimization ◽  
Damage Index ◽  
Particle Swarm ◽  
Seismic Damage ◽  
Backpropagation Neural Network ◽  
Swarm Optimization ◽  
Local Optima ◽  
Damage Indices ◽  
Prediction Problems

The evaluation of the vulnerability of buildings to earthquakes is of prime importance to ensure a good plan can be generated for the disaster preparedness to civilians. Most of the attempts are directed in calculating the damage index of buildings to determine and predict the vulnerability to certain scales of earthquakes. Most of the solutions used are traditional methods which are time consuming and complex. Some of initiatives have proven that the artificial neural network methods have the potential in solving earthquakes prediction problems. However, these methods have limitations in terms of suffering from local optima, premature convergence and overfitting. To overcome this challenging issue, this paper introduces a new solution to the prediction on the seismic damage index of buildings with the application of hybrid back propagation neural network and particle swarm optimization (BPNN-PSO) method. The prediction was based on damage indices of 35 buildings around Malaysia. The BPNN-PSO demonstrated a better result of 89% accuracy compared to the traditional backpropagation neural network with only 84%. The capability of PSO supports fast convergence method has shown good effort to improve the processing time and accuracy of the results.

scholarly journals FRP Composite in Mitigating Seismic Risk of RC Structures in Near-Fault Regions with/without Aftershocks

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Vui Van Cao ◽  
Son Quang Pham
Keyword(s):  
Plastic Hinge ◽  
Time History ◽  
Damage State ◽  
Rc Structures ◽  
Seismic Sequences ◽  
Near Fault ◽  
Damage Indices ◽  
Aftershock Sequences ◽  
Nonlinear Time History ◽  
Original Frame

The literature related to earthquakes and fibre reinforced polymer (FRP) retrofitting can be divided into two main categories: (1) the applications of FRP to retrofit structures subjected to single traditional earthquakes and (2) the effects of mainshock-aftershock sequences on original structures (without FRP retrofitting). Research on using FRP to mitigate the risk of pulse-type mainshock-aftershock sequences for reinforced concrete (RC) structures located in near-fault regions is hardly found in the literature and is thus the aim of this study. To achieve this aim, a four-storey RC frame, near-fault mainshocks, and seismic sequences were selected. The frame was retrofitted using FRP wraps at plastic hinge locations. Nonlinear time history and damage analyses of the original and FRP-retrofitted frames subjected to these near-fault mainshocks and seismic sequences were conducted. The results showed that aftershocks significantly increase the damage indices of the frames, shifting the damage state of the original frame from severe damage to collapse and the damage state of the FRP-retrofitted frame from light damage to moderate damage. FRP retrofitting successfully reduced the risk of seismic sequences by reducing the damage two levels, shifting the damage state of the original frame from collapse to moderate damage.

Seismic Retrofitting of Rectangular Bridge Columns with Composite Straps

1997 ◽  
Vol 13 (2) ◽  
pp. 281-304 ◽  
Author(s):  
H. Saadatmanesh ◽  
M. R. Ehsani ◽  
L. Jin
Keyword(s):  
Plastic Hinge ◽  
Poor Performance ◽  
High Strength ◽  
Bridge Columns ◽  
Absorption Capacity ◽  
Seismic Retrofitting ◽  
Frp Composites ◽  
Reinforced Polymer ◽  
Seismic Forces ◽  
Reversed Cyclic

Behavior of typical rectangular bridge columns with substandard design details for seismic forces was investigated. The poor performance of this type of column attested to the need for effective and economical seismic upgrading techniques. A method utilizing fiber reinforced polymer (FRP) composites to retrofit existing bridge columns is investigated in this paper. High-strength FRP straps are wrapped around the column in the potential plastic hinge region to increase confinement and to improve the behavior under seismic forces. Five rectangular columns with different reinforcement details were constructed and tested under reversed cyclic loading. Two columns were not retrofitted and were used as control specimens so that their hysteresis response could be compared with those for retrofitted columns. The results of this study indicated that significant improvement in ductility and energy absorption capacity can be achieved as a result of this retrofitting technique.

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