Optimal Trends in Seismic Design of Single Column Circular Reinforced Concrete Bridge Piers

1994 ◽  
Vol 10 (3) ◽  
pp. 589-614
Author(s):  
Ravindra Verma ◽  
M. J. Nigel Priestley

An algorithm is developed to incorporate seismic capacity design philosophy in a computer program for the optimal design of single column circular reinforced concrete bridge piers for seismic loading. The program designs the circular column as a single degree of freedom system under the combined effect of axial and lateral seismic loads over a broad range of axial load ratio, column height and design displacement ductility capacity. Flexural, confinement and shear reinforcement requirements are then assessed for the entire range of parameters and cost calculations performed. For a given column height, design displacement ductility and axial load level, results indicate the existence of an optimal column diameter and ductility level. As the column diameter is reduced, cost savings are effected by reduced volume of concrete, but tend to be offset by P-Δ effects, increased longitudinal reinforcement for flexure, and increased transverse reinforcement for confinement and shear. Based on common trends, solutions are provided for the most economical range of the axial load ratio and design displacement ductility capacity for a given column height.

Author(s):  
M. J. N. Priestley ◽  
M. J. Kowalsky

Moment-curvature analyses of cantilever shear walls are used to show that yield curvature, serviceability curvature, and ultimate (damage-control) curvature are insensitive to variations of axial load ratio, longitudinal reinforcement ratio, and distribution of longitudinal reinforcement. The results are used to determine available displacement ductility factors for walls of different aspect ratios and drift limits. It is shown that drift capacity will generally exceed code levels of permissible drift, and that code drift limits will normally restrict, sometimes severely, the design displacement ductility factor.


2011 ◽  
Vol 50-51 ◽  
pp. 547-553
Author(s):  
Gang Zheng ◽  
Gui Qian Li

Based on the basic requirements of current Guidelines for Seismic Design of Highway Bridges, the orthogonal quasi-static test of four factors (shear-span ratio, longitudinal reinforcement diameter, axial-load ratio and spiral reinforcement ratio) at three different levels for circular reinforced concrete bridge columns has been designed. With test data the damage state, displacement ductility, capacity of accumulative energy dissipation to ultimate displacement state of bridge columns subjected to low-cyclic loading have been analyzed systematically so as to investigate effects of factors such as shear-span ratio, axial-load ratio, longitudinal reinforcement ratio and spiral reinforcement ratio on ductility performance of bridge columns.


2008 ◽  
Vol 22 (31n32) ◽  
pp. 5755-5761 ◽  
Author(s):  
ZHE LI ◽  
HAO QIN ◽  
HUI DANG ◽  
HUI LI ◽  
JIAN-SHAN ZHANG

The horizontal press performance of column is deteriorated because of its special-shaped section. Moreover, because the antiseismic performance of column is worse, special-shaped column is only used in regions where seismic intensity is lower. So the main problem is to enhance the ductility and shear capacity. This test study on mechanical performance has been carried out through 14 SRCLSSC and 2 RCLSSC. The study focuses on the impacts of test axial load ratio (nt), hooped reinforcement ratio (ρ v ), shear span ratio (λ) and steel ratio (ρ ss ) on the shear strength and the antiseismic performance of SRCLSSC. It can be concluded that the shear strength of SRCLSSC is increasing with the increasing of n t and ρ ss , but the degree of increasing is small when n t is a certainty value, and that the shear strength of SRCLSSC is decreasing with increasing of λ; The shear resistance formula of L-shaped column is derived through tests, the calculated results are in correspondence with those of the tests. It also can be concluded that the hysteretic loops of the SRCLSSC are full and the hysteretic behaviors are improved; the displacement ductility is increasing with increasing of ρv and ρ ss , but decreasing with the increasing of n t ; the degree of variety in high axial load ratio is larger than that in low axial load ratio. If steel bars are added, the shear strength and displacement ductility of SRCLSSC are increased in a large degree.


2013 ◽  
Vol 376 ◽  
pp. 231-235
Author(s):  
Cheng Li ◽  
Yun Zou ◽  
Jie Kong ◽  
Zhi Wei Wan

Nonlinear numerical analysis for the force performance of frame middle joint is processed in this paper with the finite element software of ABAQUS. Compared with experimental results, numerical analysis results are found to be reasonable. Then the influence of factors such as shaped steel ratio and axial-load ratio are contrastively analyzed. The results show that shaped steel ratio has a greater influence on the bearing capacity and hysteretic performance of the structure, but the axial-load ratio has less influence.


2014 ◽  
Vol 578-579 ◽  
pp. 936-939 ◽  
Author(s):  
Qian Qian Sun ◽  
Yun Zou ◽  
Qiang Wang

Nonlinear numerical analysis of the stress performance of SRC-RC transfer columns was carried out in this paper with the finite element software of ABAQUS. Compered with the experimental result , numerical analysis result are found to be reasonable.Then the influence of factors such as extension length of shape steel , area ratio of shape steel and axial-load ratio were contrastively analyzed . The results show that extension length of shape steel and the area ratio of shape steel have a greater influence on the bearing capacity and the hysteretic performance of transfer column ,but axial-load ratio has less influence .


2021 ◽  
pp. 875529302110492
Author(s):  
Alan Rivera-Figueroa ◽  
Luis A Montejo

This article investigates three different approaches to generate seismic input compatible with RotD100 design spectra: (1) separately matching each horizontal component to the target spectrum, (2) separately matching and then scaling-down the records to improve the match and (3) directly pursuing the match of RotD100 by simultaneously modifying both horizontal components. We examine the strong motion characteristics of the resulting records individually and their variability as suites of input records. The records generated, along with a set of amplitude-scaled records, are used as input for bi-directional non-linear response history analyses of idealized single column reinforced concrete bridge piers with different geometric and reinforcement characteristics. It is shown that the records generated pursuing a direct match of the target spectrum attain the closest match, retain better the strong motion characteristics of the seed records and their horizontal components exhibit a spectral variability comparable to suites of amplitude-scaled records. Regarding the effect on seismic response, the suites constructed separately matching each component consistently imposed larger peak inelastic and total energy demands than all other suites. Directly pursuing the match of RotD100 generated responses close but consistently below the expected from amplitude-scaled suites. The best results were obtained using the direct match methodology but using as target 110% the RotD100 spectrum as required in ASCE 7-16.


2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Bin Wang ◽  
Wenzhe Cai ◽  
Qingxuan Shi

Sectional deformation quantities, such as curvature and ductility, are of prime significance in the displacement-based seismic design and performance evaluation of structural members. However, few studies on the estimates of curvatures at different limit states have been performed on asymmetric flanged walls. In this paper, a parametric study was performed for a series of T-shaped wall cross-sections based on moment-curvature analyses. By investigating the effects of the axial load ratio, reinforcement content, material properties, and geometric parameters on curvatures at the yield and ultimate limit state, we interpret the variation in curvature with different influencing factors in detail according to the changes of the neutral axis depth. Based on the regression analyses of the numerical results of 4941 T-shaped cross-sections, simple expressions to estimate the yield curvature and ultimate curvature for asymmetric flanged walls are developed, and simplified estimates of the ductility capacity including curvature ductility and displacement ductility are further deduced. By comparing with the experimental results, we verify the accuracy of the proposed formulas. Such simple expressions will be valuable for the determination of the displacement response of asymmetric flanged reinforced concrete walls.


2011 ◽  
Vol 243-249 ◽  
pp. 149-155 ◽  
Author(s):  
Zhe Li ◽  
Shao Ji Chen ◽  
Ye Ni Wang ◽  
Cui Ping Zhang ◽  
Jing Xu

The neutral axis change along with axial load ratio, load angle, section size etc. For the neutral axis of SRCLSC(steel reinforced concrete L-shaped column) is neither plumb with the plane that the moment work on, nor parallel with borderlines of SRCLSC section, it is difficult to get loading capacity and ductility of SRCLSC on biaxial eccentric loading. Based on the plane-section assumption, a method for the nonlinear analysis of complete response process for ductility of 15 SRCLSC..It include 36 sets for load angle, 6 sets for axial load ratio, 3 sets for concrete strength, 3 sets for the content of steel, 2 sets for steel style, 3 sets for stirrup ratio, 3 sets for steel location, 3 sets for section size, 3 sets for stirrup diameter about SRCLSC. The ductile behavior of L-shaped, with calculating 1068 loading conditions,are investigated. It concluded that axial load ratio, load angle, and ratio of the spacing of stirrups and longitudinal reinforcement’s diameter (s/d) are most important factors.


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