Damage Assessment of RC Frame Structures under Multi-Earthquake Sequences

2012 ◽  
Vol 446-449 ◽  
pp. 739-744 ◽  
Author(s):  
Wei Huang ◽  
Jiang Qian ◽  
Bin Bin Zhuang ◽  
Qiu Shi Fu
Keyword(s):  
Damage Assessment ◽  
Damage Accumulation ◽  
Damage Index ◽  
Rc Frame ◽  
Damage State ◽  
Lateral Drift ◽  
Seismic Sequences ◽  
Aftershock Sequences ◽  
Rc Frame Structures ◽  
Earthquake Sequences

This paper presents the results of a numerical investigation aimed at evaluation of damage accumulation in structures under different seismic sequences. For this purpose, a multi-story RC frame model representing the typical buildings was built and subjected to four sets of different repeating seismic sequences with different magnitude. The results indicate that the aftershock sequences will increase the damage accumulation in structures, and the damage index based on the Park and Ang model can qualitatively and quantitatively ascertain the damage state of the structure instead of the single index based on the lateral drift demands. Additionally, different sequences with the identical energy input will cause the same damage state in structures.

Damage Assessment of RC Frame Structures under Multi-Earthquake Sequences

2012 ◽  
Vol 446-449 ◽  
pp. 739-744
Author(s):  
Wei Huang ◽  
Jiang Qian ◽  
Bin Bin Zhuang ◽  
Qiu Shi Fu
Keyword(s):  
Damage Assessment ◽  
Frame Structures ◽  
Rc Frame ◽  
Rc Frame Structures ◽  
Earthquake Sequences

Cumulative damage effects of mainshock-aftershock sequences on RC-frame structures

2019 ◽  
Vol 32 (3-4) ◽  
pp. 157-169
Author(s):  
Lingxin Zhang ◽  
◽  
Baijie Zhu ◽  
Yunqin Xue ◽  
Jialu Ma ◽  
...  
Keyword(s):  
Cumulative Damage ◽  
Frame Structures ◽  
Rc Frame ◽  
Aftershock Sequences ◽  
Rc Frame Structures

scholarly journals Seismic Damage Accumulation in Highway Bridges in Earthquake-Prone Regions

2015 ◽  
Vol 31 (1) ◽  
pp. 115-135 ◽  
Author(s):  
Jayadipta Ghosh ◽  
Jamie E. Padgett ◽  
Mauricio Sánchez-Silva
Keyword(s):  
Service Life ◽  
Damage Accumulation ◽  
Main Shock ◽  
Prediction Models ◽  
Time Window ◽  
Damage Index ◽  
Active Regions ◽  
Highway Bridges ◽  
Main Shocks ◽  
Aftershock Sequences

Civil infrastructures, such as highway bridges, located in seismically active regions are often subjected to multiple earthquakes, including multiple main shocks during their service life or main shock–aftershock sequences. Repeated seismic events result in reduced structural capacity and may lead to bridge collapse, causing disruption in the normal functioning of transportation networks. This study proposes a framework to predict damage accumulation in structures subjected to multiple shock scenarios after developing damage index prediction models and accounting for the probabilistic nature of the hazard. The versatility of the proposed framework is demonstrated on a case-study highway bridge located in California for two distinct hazard scenarios: (1) multiple main shocks during the service life and (2) multiple aftershock earthquake occurrences following a single main shock. Results reveal that in both cases there is a significant increase in damage index exceedance probabilities due to repeated shocks within the time window of interest.

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.

scholarly journals Refined Seismic Design Method for RC Frame Structures to Increase the Collapse Resistant Capacity

2020 ◽  
Vol 10 (22) ◽  
pp. 8230
Author(s):  
Mengmeng Gao ◽  
Shuang Li
Keyword(s):  
Seismic Design ◽  
Design Method ◽  
Frame Structure ◽  
Elastic Response ◽  
Frame Structures ◽  
Rc Frame ◽  
Structural Collapse ◽  
Damage State ◽  
Rc Frame Structures ◽  
Seismic Design Method

In current structural design codes, elastic vibration modes are used for seismic design. However, when a structure is subjected to strong earthquakes and inelastic response or even when collapse damage is observed, the damage state is always unevenly distributed along the height of the structure. Such a phenomenon implies the materials of stories with elastic response and slight damage are not fully utilized. In this paper, a new practical and effective method, which improves collapse resistant capacity by making full use of materials, is proposed for reinforcement concrete (RC) frame structures at a structural collapse state. In this method, incremental dynamic analysis (IDA) is used to evaluate the structural collapse capacity. Tangent_ratio (TR) is formulated based on the IDA curves, and the longitudinal reinforcement of columns is modified based on the TR to achieve uniform distribution of damage along the height of building. Fewer variables are optimized and constraints of the provisions in current codes are considered, which makes the proposed procedure more computationally efficient and practical. The proposed method is employed on a 5-story RC frame structure to illustrate its feasibility and practicality. Comparison work indicates that the refined seismic design method can significantly increase the collapse resistant capacity and decrease the maximum inter-story drift ratio response under strong ground motion in a few iterative steps without a cost increase.

Theoretical Forecasting and Experimental Validation of Damage Tolerance and Accumulation in Glass/Epoxy Laminates

1992 ◽  
Vol 11 (1) ◽  
pp. 56-81 ◽  
Author(s):  
N. Bonora ◽  
M. Marchetti ◽  
P. P. Milella
Keyword(s):  
Composite Material ◽  
Damage Accumulation ◽  
Elastic Moduli ◽  
Glass Fibers ◽  
Damage Index ◽  
Frequency Effect ◽  
Damage State ◽  
Matrix Cracks ◽  
Stress Levels ◽  
Number Of Cycles

Damage and damage accumulation mechanisms under cyclic loads were studied in orthotropic cross-ply composite laminates realized in S-glass fibers with epoxy resin. Five different basic mechanisms of damage were observed and evaluated making use of x-ray and dye-penetrant nondestructive techniques. They are: transverse matrix cracks, fiber failure, fiber debonding, intralaminar delamination and random disperse longitudinal cracks. The effects of these different damage mechanisms are revealed through the reduction of the mechanical properties of the composite material. A comprehensive experimental analysis of GFRP and CFRP, with two different lay-ups for each one, was made. Variations of the elastic moduli in two different directions and Poisson's ratio were measured as a function of the number of cycles, for different stress levels, under alternate loads. The basic relations, developed by Talreja et al., which permit the prediction of the reduction of the elastic moduli for a given damage state, were directly related to the number of cycles N and to the stress levels employed in the fatigue tests. Tests to evaluate an eventual frequency effect on damage accumulation processes in composite material were made. Cumulative damage tests were also conducted to analyse material response under different and alternate load spectra. A damage index based on residual normalized strain energy ratio, which can describe a global damage state, is also proposed.

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