Probabilistic Evaluation of Effects of Column Moment Magnification Factor on Seismic Performance of Reinforced Concrete Frames

2011 ◽  
Vol 243-249 ◽  
pp. 251-257 ◽  
Author(s):  
Ming Ji He ◽  
Chun Yang ◽  
Jian Cai ◽  
Yan Sheng Huang ◽  
Yi Wu
Keyword(s):  
Reinforced Concrete ◽  
Failure Mode ◽  
Seismic Performance ◽  
Seismic Vulnerability ◽  
Failure Modes ◽  
Fragility Curves ◽  
Frame Structures ◽  
Rc Frame ◽  
Magnification Factor ◽  
Rc Frame Structures

Enhancing column flexural capacity is the key measure in seismic capacity design to achieve strong column-weak beam failure mode and determinate the probabilistic relation between column moment magnification factor (CMMF). In the paper the effects of column moment magnification factor on seismic performance of reinforced concrete (RC) frames are evaluated to limit the occurrence probability of column-hinging failure modes within an acceptable tolerance. Monte Carlo simulation methodology is used to calculate the probability of drift demand exceeding drift capacity of two typical frame structures with consideration of major uncertainties. And fragility curves are constructed to obtain the relationship between CMMF and probability of structural damages and assess the seismic vulnerability of RC frame structures. Results show that the seismic performance of RC frame structures can be significantly enhanced by improving CMMF. The CMMF is required to be equal to or greater than 2.0 to achieve acceptable probability of exceedance of column-hinging failure mode.

Seismic Performance of Reinforced Concrete Frame Buildings in Southern California

2011 ◽  
Vol 27 (2) ◽  
pp. 399-418 ◽  
Author(s):  
Kathryn P. Lynch ◽  
Kristen L. Rowe ◽  
Abbie B. Liel
Keyword(s):  
Reinforced Concrete ◽  
Los Angeles ◽  
Seismic Performance ◽  
Southern California ◽  
Frame Structures ◽  
Rc Frame ◽  
Frame Buildings ◽  
Rc Frame Structures ◽  
Rc Frame Buildings ◽  
The Impact

This study examines the impact of the ShakeOut earthquake on reinforced concrete (RC) frame structures in Southern California. The assessment uses synthetic ground motions and nonlinear dynamic analysis to evaluate 20 RC frame buildings hypothetically located at 735 sites throughout the region. Results show that older nonductile RC frame structures may collapse at 8% to 32% of the sites analyzed, especially in Palm Springs, Los Angeles, and San Bernardino. Modern code-conforming RC frame structures are predicted to collapse at fewer sites (1–11%), but modern midrise construction may be vulnerable in Los Angeles due to rupture directivity and basin effects. These seismic performance metrics can inform the development of policies for emergency response and for mitigating earthquake-induced collapse of existing RC frame buildings. The study further provides a prototype that can be used in developing future scenario studies that will benefit from ongoing research to improve building and seismological models.

Design Forces for Drift and Damage Control: A Second Look at the Substitute Structure Approach

1994 ◽  
Vol 10 (2) ◽  
pp. 319-331 ◽  
Author(s):  
John F. Bonacci
Keyword(s):  
Reinforced Concrete ◽  
Damage Control ◽  
Dynamic Test ◽  
Frame Structures ◽  
Rc Frame ◽  
Test Results ◽  
Structure Approach ◽  
Maximum Displacement ◽  
Design Loads ◽  
Rc Frame Structures

This paper explores the development of a method that is useful for design of reinforced concrete (RC) frame structures to resist earthquakes. The substitute structure method, originally proposed in the 1970s, makes an analogy between viscously damped linear and hysteretic response for the purpose of estimating maximum displacement. The evolution of the method is retraced in order to emphasize its unique reliance on experimental results, which are needed to establish rules for assignment of substitute linear properties. Recent dynamic test results are used to extend significantly the calibration of the method, which furnishes design loads on the basis of drift and damage control.

scholarly journals Cyclic Tests and Numerical Analyses on Bolt-Connected Precast Reinforced Concrete Deep Beams

2021 ◽  
Vol 11 (12) ◽  
pp. 5356
Author(s):  
Jing Li ◽  
Lizhong Jiang ◽  
Hong Zheng ◽  
Liqiang Jiang ◽  
Lingyu Zhou
Keyword(s):  
Reinforced Concrete ◽  
Failure Mode ◽  
Seismic Performance ◽  
High Strength ◽  
Length Ratio ◽  
Frame Structures ◽  
Initial Stiffness ◽  
Frame Buildings ◽  
Parametric Analyses ◽  
Bending Failure

A bolt-connected precast reinforced concrete deep beam (RDB) is proposed as a lateral resisting component that can be used in frame structures to resist seismic loads. RDB can be installed in the steel frame by connecting to the frame beam with only high-strength bolts, which is different from the commonly used cast-in-place RC walls. Two 1/3 scaled specimens with different height-to-length ratios were tested to obtain their seismic performance. The finite element method is used to model the seismic behavior of the test specimens, and parametric analyses are conducted to study the effect on the height-to-length ratio, the strength of the concrete and the height-to-thickness ratio of RDBs. The experimental and numerical results show that the RDB with a low height-to-length ratio exhibited a shear–bending failure mode, while the RDB with a high height-to-length ratio failed with a shear-dominated failure mode. By comparing the RDB with a height-to-length ratio of 2.0, the ultimate capacity, initial stiffness and ductility of the RDB with a height-to-length ratio of 0.75 increased by 277%, 429% and 141%, respectively. It was found that the seismic performance of frame structures could be effectively adjusted by changing the height-to-length ratio and length-to-thickness of the RDB. The RDB is a desirable lateral-resisting component for existing and new frame buildings.

Investigation of Global Equivalent Damping and Statistical Relationship of Displacement between Nonlinear Static and Dynamic Analysis of Reinforced Concrete Frame Structures

2018 ◽  
Vol 34 (3) ◽  
pp. 1311-1338 ◽  
Author(s):  
Lulu Yan ◽  
Jinxin Gong ◽  
Qin Zhang
Keyword(s):  
Reinforced Concrete ◽  
Degree Of Freedom ◽  
Design Parameters ◽  
Frame Structures ◽  
Equivalent Linearization ◽  
Rc Frame ◽  
Static And Dynamic Analysis ◽  
Equivalent Damping ◽  
Nonlinear Static ◽  
Rc Frame Structures

The assessment of the seismic performance of reinforced concrete (RC) frame structures using the equivalent linearization approach requires comprehensive insight into the nonlinear response of the system, and most previous researches focused on the analysis of a single-degree-of-freedom (SDOF) system. To describe the hysteretic behavior of a multi-degree-of-freedom (MDOF) system accurately, monotonic and cyclic pushover analyses for 88 RC frames structures with various configurations and design parameters are carried out and a unified hysteresis loop expression modeling the cyclic pushover results of RC frame system is developed. Then, a global equivalent damping based on Jacobsen's approach is derived, and comparisons between the displacements obtained by nonlinear static analysis (NSA) utilizing the derived global equivalent damping and those obtained by nonlinear time history analysis (NTHA) are made. Finally, a modified global equivalent damping is presented by calibrating the derived Jacobsen's equivalent damping through NTHA results. Based on the modified equivalent damping, the statistical analysis of the ratios of the results obtained by NTHA to those obtained by NSA is implemented to predicate the probabilistic seismic displacement demands of RC frame structures.

scholarly journals Seismic Performance Assessments of RC Frame Structures Strengthened by External Precast Wall Panel

2020 ◽  
Vol 10 (5) ◽  
pp. 1749
Author(s):  
Seung-Ho Choi ◽  
Jin-Ha Hwang ◽  
Sun-Jin Han ◽  
Hyo-Eun Joo ◽  
Hyun-Do Yun ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Seismic Performance ◽  
Precast Concrete ◽  
Frame Structure ◽  
Frame Structures ◽  
Rc Frame ◽  
Analysis Model ◽  
Energy Dissipation Capacity ◽  
Precast Walls ◽  
Rc Frame Structures

In recent years, a variety of strengthening methods have been developed to improve the seismic performance of reinforced concrete (RC) frame structures with non-seismic details. In this regard, this study proposes a new type of seismic strengthening method that compresses prefabricated precast concrete (PC) walls from the outside of a building. In order to verify the proposed method, a RC frame structure strengthened with precast walls was fabricated, and cyclic loading tests were performed. The results showed that specimens strengthened using the proposed method exhibited further improvements in strength, stiffness and energy dissipation capacity, compared to RC frame structures with non-seismic details. In addition, a nonlinear analysis method, capable of considering the flexural compression and shear behaviors of the walls, was suggested to analytically evaluate the structural behavior of the frame structures strengthened by the proposed method. Using this, an analysis model for frame structures strengthened with precast walls was proposed. Through the proposed model, the analysis and test results were compared in relation to stiffness, strength, and energy dissipation capacity. Then, the failure mode of the column was evaluated based on the pushover analysis. In addition, this study proposed a simplified analysis model that considered the placement of longitudinal reinforcements in shear walls.

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