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.

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.

Collapse Simulation of Damaged Reinforced Concrete Frame Structures in Earthquakes

2019 ◽  
Author(s):  
Yang Yang ◽  
Xianglin Gu
Keyword(s):  
Reinforced Concrete ◽  
Full Range ◽  
Simulation System ◽  
Frame Structures ◽  
Rc Frame ◽  
Steel Bar ◽  
Damage States ◽  
Collapse Behavior ◽  
Rc Frame Structures ◽  
The Impact

<p>A simulation system based on the discrete element method (DEM) was developed to simulate the collapse behavior of damaged reinforced concrete (RC) frame structures in earthquakes. A frame structure was discretized into beam-column-joint discrete system according to its failure mode. The elements were assumed to be cuboid, and a group of concrete springs and steel bar springs were set between two adjacent elements to represent their interactions. The failure of material was initiated by fracture of springs, and the impact actions among separated components were considered. Using the simulation system, the full-range collapse process of an RC frame, including debris stacking, was visually simulated. The efficiency of the system was verified by comparing the simulated collapse behavior with that observed in a collapse experiment. A new method, in which concrete springs and steel bar springs were cut off in advance to simulate the respective initial imperfection, was proposed to model earthquake-induced damage states of RC frame structures. Then displacement loadings were conducted to form the respective damage states. Finally, a parametric analysis was conducted to investigate the collapse processes of the RC frame with different scenarios of initial damage. The results indicated that the initial damages on columns were of greater influence on collapse patterns than the initial damages on beams, and the residual interstory drifts were nonnegligible in evaluating the structural collapse resistance.</p>

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.

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.

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