EERI Annual Student Paper Award Confinement of Rectangular Bridge Columns in Moderate Seismic Areas

1998 ◽  
Vol 14 (2) ◽  
pp. 397-406 ◽  
Author(s):  
Nadim Wehbe
Keyword(s):  
Axial Load ◽  
Bridge Columns ◽  
Transverse Reinforcement ◽  
Displacement Ductility ◽  
Reinforced Concrete Bridge ◽  
Student Paper ◽  
And Behavior ◽  
Lateral Reinforcement ◽  
Constant Axial Load ◽  
Rectangular Columns

The work presented in this paper examines the ductility and behavior of rectangular reinforced concrete bridge columns with moderate confinement. Four half-scaled rectangular columns were built and tested. The transverse reinforcement ratios provided in the strong direction of the column specimens corresponded to 46 percent and 60 percent of the minimum lateral reinforcement required by AASHTO for seismic detailing. Each specimen was tested under constant axial load while subjected to quasi-static cyclic lateral loading in the column strong direction. The axial load indexes were 10 percent and 25 percent. The specimens exhibited displacement ductilities ranging between 5 and 7. Based on analytical and experimental results, a simple design equation relating the amount of confinement steel to attainable displacement ductility was developed.

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
Keyword(s):  
Axial Load ◽  
Load Ratio ◽  
Bridge Piers ◽  
Column Height ◽  
Column Diameter ◽  
Displacement Ductility ◽  
Reinforced Concrete Bridge ◽  
Axial Load Ratio ◽  
Single Column ◽  
Ductility Capacity

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.

scholarly journals Shear Strength Model for Reinforced Concrete Columns with Low Transverse Reinforcement Ratios

2014 ◽  
Vol 17 (10) ◽  
pp. 1373-1385 ◽  
Author(s):  
Cao Thanh Ngoc Tran ◽  
Bing Li
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Axial Load ◽  
Concrete Columns ◽  
Transverse Reinforcement ◽  
Reinforced Concrete Column ◽  
Reinforced Concrete Columns ◽  
Existing Structures ◽  
Reversed Cyclic ◽  
Constant Axial Load

This paper introduces an equation developed based on the strut-and-tie analogy to predict the shear strength of reinforced concrete columns with low transverse reinforcement ratios. The validity and applicability of the proposed equation are evaluated by comparison with available experimental data. The proposed equation includes the contributions from concrete and transverse reinforcement through the truss action, and axial load through the strut action. A reinforced concrete column with a low transverse reinforcement ratio, commonly found in existing structures in Singapore and other parts of the world was tested to validate the assumptions made during the development of the proposed equation. The column specimen was tested to failure under the combination of a constant axial load of 0.30 f' c A g and quasi-static cyclic loadings to simulate earthquake actions. The analytical results revealed that the proposed equation is capable of predicting the shear strength of reinforced concrete columns with low transverse reinforcement ratios subjected to reversed cyclic loadings to a satisfactory level of accuracy

Strength Degradation of Existing Bridge Columns under Seismic Loading

1996 ◽  
Vol 1541 (1) ◽  
pp. 29-42
Author(s):  
Omar A. Jaradat ◽  
David I. McLean ◽  
M. Lee Marsh
Keyword(s):  
Shear Failure ◽  
Seismic Loading ◽  
Experimental Tests ◽  
Bridge Columns ◽  
Lap Splices ◽  
Reinforced Concrete Bridge ◽  
Bar Buckling ◽  
Existing Bridges ◽  
Shear Behaviors ◽  
Constant Axial Load

The strength and degradation behavior of reinforced concrete bridge columns under seismic loading were investigated. Experimental tests were conducted on four reduced-scale column specimens that incorporated deficiencies selected to be representative of those present in existing bridges designed before 1971. The columns were fixed against rotation at both the top and bottom, resulting in a transfer of shear forces through the column even after the lower hinging region lost its flexural capacity. The specimens were subjected to increasing levels of cycled inelastic displacements under constant axial load. The focus of the study was to characterize the load and displacement capacities present in older columns for purposes of seismic assessment and retrofit design. Flexure-dominated failures occurred in three of the specimens. A rapid degradation in flexural strength was observed at the bottom hinging regions of the tested columns because of the presence of lap splices and poor confinement. Top hinging regions that did not have lap splices exhibited degradation in flexural capacities at higher displacement ductilities because of eventual longitudinal bar buckling. In the fourth specimen, flexural yielding was initially observed at both the top and bottom of the column, but this was followed by an eventual brittle shear failure. Various procedures for assessing flexural and shear behaviors were compared with the observed experimental results.

scholarly journals Behaviour of ductile hollow reinforced concrete columns

1983 ◽  
Vol 16 (4) ◽  
pp. 273-290 ◽  
Author(s):  
J. B. Mander ◽  
M. J. N. Priestley ◽  
R. Park
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Plastic Hinge ◽  
Concrete Columns ◽  
Bridge Piers ◽  
Reinforced Concrete Bridge ◽  
Hinge Zone ◽  
Lateral Displacements ◽  
Transverse Steel ◽  
Constant Axial Load

An experimental investigation into the seismic performance of ductile hollow reinforced concrete bridge piers is described. Four 3.2 m high specimens, 750 mm square with 120 mm thick walls containing 60 longitudinal steel bars and different arrangements of confining steel in the plastic hinge zone were subjected to a constant axial load and cyclic lateral displacements. An assessment of the effect of axial load and the amount of transverse steel on the rotational capacity of the plastic hinge is made. The specimens performed satisfactorily at member ductilities between 6 and 8 without 
any significant degradation of strength under cyclic loading.

Experimental Evaluation of the Seismic Performance of Circular Reinforced Concrete Bridge Columns

2011 ◽  
Vol 50-51 ◽  
pp. 547-553
Author(s):  
Gang Zheng ◽  
Gui Qian Li
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Load Ratio ◽  
Bridge Columns ◽  
Reinforcement Ratio ◽  
Concrete Bridge ◽  
Longitudinal Reinforcement ◽  
Shear Span ◽  
Reinforced Concrete Bridge ◽  
Axial Load Ratio

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.

Analysis for optimization of spiral reinforcement in pre-fabricated bridge columns

2021 ◽  
Author(s):  
Lubos Rehounek ◽  
Jan Cervenka ◽  
Radomír Pukl
Keyword(s):  
Energy Consumption ◽  
Numerical Model ◽  
Nonlinear Analysis ◽  
Co2 Emission ◽  
Bridge Columns ◽  
Structural Performance ◽  
Transverse Reinforcement ◽  
Cyclic Response ◽  
Reduction Of Co2 ◽  
Rectangular Columns

<p>Savings and optimization in the use of steel and concrete can significantly contribute to the reduction of CO2 emission and energy consumption, promoting a greener environment for the place we live. It has been shown that the use of multi-spiral reinforcement (MSR) in square or rectangular columns can significantly save the amount of steel for transverse reinforcement and yet can still achieve a higher structural performance than conventional tie reinforcement. The paper presents a validation of a numerical model for nonlinear analysis of novel multi-spiral reinforcement in prefabricated columns. The validated model will be used for the subsequent studies and optimization of the spiral reinforcement location, diameter and pitch. Selected arrangements of the multi-spiral reinforcements have been analysed to demonstrate their effectiveness in static and cyclic response.</p>

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