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.

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.

Seismic Performance of High Titanium Heavy Slag High Strength Concrete Columns

2012 ◽  
Vol 174-177 ◽  
pp. 455-459 ◽  
Author(s):  
Xiao Wei Li ◽  
Xue Wei Li ◽  
Xin Yuan
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
High Strength Concrete ◽  
Load Ratio ◽  
High Strength ◽  
Scale Model ◽  
Transverse Reinforcement ◽  
Reinforced Concrete Column ◽  
Displacement Ductility ◽  
Strength Concrete

For expedite the development of high titanium heavy slag concrete, eight high titanium heavy slag high strength reinforced concrete (HTHS-HSRC) scale model column are studied. The eight HTHS-HSRC model columns are tested under reversed horizontal force. Primary experimental parameters include axial load ratio varying from 0.3 to 0.5, volumetric ratios of transverse reinforcement ranging from 1.38% to 1.56%, strength of high titanium heavy slag high strength concrete varying from 55.9 to 61.6 N/mm2 and configurations of transverse reinforcement. It is found from the test result that HTHS-HSRC model columns provides comparable seismic performance to those usually used reinforced concrete column in terms of member ductility, hysteretic and energy dissipation capacity. Primary Factors of Displacement Ductility of Model Columns are also discussed.

scholarly journals Steel Plate Cold-Rolled Section Steel Embedded High-Strength Concrete Low-Rise Shear Wall Seismic Performance

2018 ◽  
Vol 2018 ◽  
pp. 1-18
Author(s):  
Min Gan ◽  
Yu Yu ◽  
Liren Li ◽  
Xisheng Lu
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Seismic Performance ◽  
High Strength Concrete ◽  
Steel Plate ◽  
Shear Walls ◽  
High Strength ◽  
Shear Wall ◽  
Steel Plates ◽  
Strength Concrete

Four test pieces with different steel plate center-to-center distances and reinforcement ratios are subjected to low-cycle repeat quasistatic loading to optimize properties as failure mode, hysteretic curve, skeleton curve, energy dissipation parameters, strength parameters, and seismic performance of high-strength concrete low-rise shear walls. The embedded steel plates are shown to effectively restrict wall crack propagation, enhance the overall steel ratio, and improve the failure mode of the wall while reducing the degree of brittle failure. Under the same conditions, increasing the spacing between the steel plates in the steel plate concrete shear wall can effectively preserve the horizontal bearing capacity of the shear wall under an ultimate load. The embedded steel plates perform better than concealed bracing in delaying stiffness degeneration in the low-rise shear walls, thus safeguarding their long-term bearing capacity. The results presented here may provide a workable basis for shear wall design optimization.

scholarly journals Size Effect on the Seismic Performance of High-Strength Reinforced Concrete Columns with Different Shear Span-to-Depth Ratios

2018 ◽  
Vol 2018 ◽  
pp. 1-19
Author(s):  
Chunyi Yu ◽  
Hua Ma ◽  
Yongping Xie ◽  
Zhenbao Li ◽  
Zhenyun Tang
Keyword(s):  
Reinforced Concrete ◽  
Size Effect ◽  
Seismic Performance ◽  
Factor Of Safety ◽  
Shear Failure ◽  
High Strength ◽  
Concrete Columns ◽  
Reinforced Concrete Columns ◽  
Local Factor ◽  
Shear Span

The size effect on the seismic performance of conventional reinforced concrete columns has been observed in terms of flexural failure and shear failure. Under earthquake loading, slender columns experience flexural failure, and short columns experience flexure-shear failure and shear failure. However, the effect of section size on the seismic performance of high-strength reinforced concrete columns under the conditions of different shear span-to-depth ratios requires further confirmation. For this purpose, six high-strength reinforced concrete columns with shear span-to-depth ratios of 2 and 4 were subjected to cyclic loading in this study. The experimental results indicated that relative nominal flexural strength, energy dissipation coefficient, factor of safety, and local factor of safety all exhibited a strong size effect by decreasing with increasing column size. Furthermore, the size effect became stronger as the shear span-to-depth ratio was increased, except for average energy dissipation coefficient. The observed changes in the factor of safety were in good agreement with the Type 2 size effect model proposed by Bažant. Thus, based on the local factor of safety and Bažant’s Type 2 model, the code equation for moment capacity of different shear span-to-depth ratios was modified to provide a consistent factor of safety regardless of column size.

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