Seismic Performance of Circular Reinforced Concrete Columns Under Varying Axial Load

Seismic Performance of Circular Reinforced Concrete Columns Under Varying Axial Load PDF Author: Gianmario Benzoni
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 214

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Book Description
The behavior of four circular reinforced concrete bridge columns, with different axial load regimes, is investigated. The first unit was tested under constant compressive axial load corresponding to an axial load ratio of 0.35. The second specimen was subjected to a constant tensile axial force equivalent to 0.087 axial load ratio. Two specimens were tested under varying regime of axial load, ranging between the two previous load limits, in order to simulate realistic seismic conditions of outer columns of multi-column bents. Extended comparison between experimental and predicted shear response, from different current equations, is provided.

Seismic Performance of Circular Reinforced Concrete Columns Under Varying Axial Load

Seismic Performance of Circular Reinforced Concrete Columns Under Varying Axial Load PDF Author: Gianmario Benzoni
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 214

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Book Description
The behavior of four circular reinforced concrete bridge columns, with different axial load regimes, is investigated. The first unit was tested under constant compressive axial load corresponding to an axial load ratio of 0.35. The second specimen was subjected to a constant tensile axial force equivalent to 0.087 axial load ratio. Two specimens were tested under varying regime of axial load, ranging between the two previous load limits, in order to simulate realistic seismic conditions of outer columns of multi-column bents. Extended comparison between experimental and predicted shear response, from different current equations, is provided.

Seismic Assessment and Retrofit of Reinforced Concrete Columns

Seismic Assessment and Retrofit of Reinforced Concrete Columns PDF Author: Konstantinos G. Megalooikonomou
Publisher: Cambridge Scholars Publishing
ISBN: 1527530361
Category : Technology & Engineering
Languages : en
Pages : 387

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Book Description
Reinforced concrete columns play a very important role in structural performance. As such, it is essential to apply a suitable analytical tool to estimate their structural behaviour considering all failure mechanisms such as axial, shear, and flexural failures. This book highlights the development of a fiber beam-column element accounting for shear effects and the effect of tension stiffening through reinforcement-to-concrete bond, along with the employment of suitable constitutive material laws.

Seismic Performance of Circular Reinforced Concrete Bridge Columns Under Bidirectional Earthquake Loading

Seismic Performance of Circular Reinforced Concrete Bridge Columns Under Bidirectional Earthquake Loading PDF Author: Mahmoud Mohamad Hachem
Publisher:
ISBN:
Category :
Languages : en
Pages : 570

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Book Description


Performance of Circular Reinforced Concrete Bridge Columns Under Bidirectional Earthquake Loading

Performance of Circular Reinforced Concrete Bridge Columns Under Bidirectional Earthquake Loading PDF Author: Mahmoud M. Hachem
Publisher:
ISBN:
Category : Bridges, Concrete
Languages : en
Pages : 496

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Book Description
Describes the dynamic testing of 4 circular reinforced concrete bridge columns. The specimens were divided into 2 pairs, with each pair subjected to a different ground motion. Within each pair, one specimen was subjected to one component of the ground motion, while the other was subjected to 2 components. Two analytical studies were carried out for a wide array of column heights, diameters, and axial load intensities. The columns were subjected to large suites of ground motions scaled to match on average the design response spectrum.

Reinforced Concrete Columns Under Seismic Lateral Force and Varying Axial Load

Reinforced Concrete Columns Under Seismic Lateral Force and Varying Axial Load PDF Author: Xinrong Li
Publisher:
ISBN:
Category : Axial loads
Languages : en
Pages : 350

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Book Description


The Seismic Response of Well-confined Circular Reinforced Concrete Columns with Low Aspect Ratios

The Seismic Response of Well-confined Circular Reinforced Concrete Columns with Low Aspect Ratios PDF Author: Ngan Ha D. Vu
Publisher:
ISBN:
Category : Columns, Concrete
Languages : en
Pages : 108

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Book Description


Seismic Behavior of Circular Reinforced Concrete Bridge Columns Under Combined Loading Including Torsion

Seismic Behavior of Circular Reinforced Concrete Bridge Columns Under Combined Loading Including Torsion PDF Author: Suriya Prakash Shanmugam
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 634

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Book Description
"Reinforced concrete (RC) columns of skewed and curved bridges with unequal spans and column heights can be subjected to combined loading including axial, flexure, shear, and torsion loads during earthquakes. The combination of axial loads, shear force, and flexural and torsional moments can result in complex failure modes of RC bridge columns. This study carried out experimental and analytical studies to investigate the seismic performance of circular RC columns under combined loading including torsion. The main variables considered here were (i) the ratio of torsion-to-bending moment (T/M), (ii) the ratio of bending moment-to-shear (M/V) or shear span (H/D), and (iii) the level of detailing for high and moderate seismicity (high or low spiral ratio). In particular, the effects of the spiral reinforcement ratio and shear span on strength and ductility of circular RC columns under combined loading were addressed. In addition, the effects of torsional loading on the bending moment-curvature, ductility, and energy dissipation characteristics were also considered. The analytical investigation examined the development of existing models for flexure and pure torsion. Interaction diagrams between bending, shear and torsional loads were established from a semi-empirical approach. A damage-based design approach for circular RC columns under combined loads was proposed by decoupling damage index models for flexure and torsion. Experimental and analytical results showed that the progression of damage was amplified by an increase in torsional moment. An increase in the transverse spiral reinforcement ratio delayed the progression of damage and changed the torsional-dominated behavior to flexural-dominated behavior under combined flexural and torsional moments"--Abstract, leaf iii.

Seismic Design and Retrofit of Bridges

Seismic Design and Retrofit of Bridges PDF Author: M. J. N. Priestley
Publisher: John Wiley & Sons
ISBN: 9780471579984
Category : Technology & Engineering
Languages : en
Pages : 704

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Book Description
Because of their structural simplicity, bridges tend to beparticularly vulnerable to damage and even collapse when subjectedto earthquakes or other forms of seismic activity. Recentearthquakes, such as the ones in Kobe, Japan, and Oakland,California, have led to a heightened awareness of seismic risk andhave revolutionized bridge design and retrofit philosophies. In Seismic Design and Retrofit of Bridges, three of the world's topauthorities on the subject have collaborated to produce the mostexhaustive reference on seismic bridge design currently available.Following a detailed examination of the seismic effects of actualearthquakes on local area bridges, the authors demonstrate designstrategies that will make these and similar structures optimallyresistant to the damaging effects of future seismicdisturbances. Relying heavily on worldwide research associated with recentquakes, Seismic Design and Retrofit of Bridges begins with anin-depth treatment of seismic design philosophy as it applies tobridges. The authors then describe the various geotechnicalconsiderations specific to bridge design, such as soil-structureinteraction and traveling wave effects. Subsequent chapters coverconceptual and actual design of various bridge superstructures, andmodeling and analysis of these structures. As the basis for their design strategies, the authors' focus is onthe widely accepted capacity design approach, in which particularlyvulnerable locations of potentially inelastic flexural deformationare identified and strengthened to accommodate a greater degree ofstress. The text illustrates how accurate application of thecapacity design philosophy to the design of new bridges results instructures that can be expected to survive most earthquakes withonly minor, repairable damage. Because the majority of today's bridges were built before thecapacity design approach was understood, the authors also devoteseveral chapters to the seismic assessment of existing bridges,with the aim of designing and implementing retrofit measures toprotect them against the damaging effects of future earthquakes.These retrofitting techniques, though not considered appropriate inthe design of new bridges, are given considerable emphasis, sincethey currently offer the best solution for the preservation ofthese vital and often historically valued thoroughfares. Practical and applications-oriented, Seismic Design and Retrofit ofBridges is enhanced with over 300 photos and line drawings toillustrate key concepts and detailed design procedures. As the onlytext currently available on the vital topic of seismic bridgedesign, it provides an indispensable reference for civil,structural, and geotechnical engineers, as well as students inrelated engineering courses. A state-of-the-art text on earthquake-proof design and retrofit ofbridges Seismic Design and Retrofit of Bridges fills the urgent need for acomprehensive and up-to-date text on seismic-ally resistant bridgedesign. The authors, all recognized leaders in the field,systematically cover all aspects of bridge design related toseismic resistance for both new and existing bridges. * A complete overview of current design philosophy for bridges,with related seismic and geotechnical considerations * Coverage of conceptual design constraints and their relationshipto current design alternatives * Modeling and analysis of bridge structures * An exhaustive look at common building materials and theirresponse to seismic activity * A hands-on approach to the capacity design process * Use of isolation and dissipation devices in bridge design * Important coverage of seismic assessment and retrofit design ofexisting bridges

Reinforced Concrete Columns Under Seismic Lateral Force and Varying Axial Load

Reinforced Concrete Columns Under Seismic Lateral Force and Varying Axial Load PDF Author: Xinrong Li
Publisher:
ISBN:
Category : Axial loads
Languages : en
Pages : 350

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Book Description


Effect of Load Pattern and History on Performance of Reinforced Concrete Columns

Effect of Load Pattern and History on Performance of Reinforced Concrete Columns PDF Author: Fatemeh Shirmohammadi
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Accurate and realistic assessment of the performance of columns in general, and those in critical locations that may cause progressive failure of the entire structure, in particular, is significantly important. This performance is affected by the load history, pattern, and intensity. Current design code does not consider the effect of load pattern on the load and displacement capacity of columns. A primary research sponsored by Kansas Department of Transportation (KDOT) was conducted as the initial step of the present study (No. K-TRAN: KSU-11-5). The main goals of the KDOT project were: (1) investigation of new KDOT requirements in terms of the column design procedure and detailing and their consistency with AASHTO provisions; (2) verification of the KDOT assumptions for the plastic hinge regions for columns and bridge piers, (3) provide assessment of the load capacity of the existing columns and bridge piers in the light of the new specifications and using the new load demand as in the new provisions; and finally recommendations for columns and bridge piers that do not meet the new requirements. A conclusion was drawn that there is a need for conducting more studies on the realistic performance of Reinforced Concrete (RC) sections and columns. The studies should have included performance of RC members under various loading scenarios, assessment of columns capacity considering confinement effect provided by lateral reinforcement, and investigation on performance of various monotonic and cyclic material models applied to simulate the realistic performance. In the study reported here, monotonic material models, cyclic rules, and plastic hinge models have been utilized in a fiber-based analytical procedure, and validated against experimental data to simulate behavior of RC section under various loading scenarios. Comparison of the analytical predictions and experimental data, through moment-curvature and force-deflection analyses, confirmed the accuracy and validity of the analytical algorithm and models. The performance of RC columns under various axial and lateral loading patterns was assessed in terms of flexural strength and energy dissipation. FRP application to enhance ductility, flexural strength, and shear capacity of existing deficient concrete structures has increased during the last two decades. Therefore, various aspects of FRP-confined concrete members, specifically monotonic and cyclic behavior of concrete members confined and reinforced by FRP, have been studied in many research programs, suggesting various monotonic models for concrete confined by only FRP. Exploration of existing model performances for predicting the behavior of several tested specimens shows a need for improvement of existing algorithms. The model proposed in the current study is a step in this direction. FRP wrapping is typically used to confine existing concrete members containing conventional lateral steel reinforcement (tie/spiral). The confining effect of lateral steel reinforcement in analytical studies has been uniquely considered in various models. Most models consider confinement due to FRP and ignore the effect of conventional lateral steel reinforcement. Exploration of existing model performances for predicting the behavior of several tested specimens confined by both FRP and lateral steel shows a need for improvement of existing algorithms. A model was proposed in this study which is a step in this direction. Performance of the proposed model and four other representative models from literature was compared to experimental data from four independent databases. In order to fulfill the need for a simple, yet accurate analytical tool for performance assessment of RC columns, a computer program was developed that uses relatively simple analytical methods and material models to accurately predict the performance of RC structures under various loading conditions, including cyclic lateral displacement under a non-proportionally variable axial load (Esmaeily and Xiao 2005, Esmaeily and Peterman 2007). However, it was limited to circular, rectangular, and hollow circular/rectangular sections and uniaxial lateral curvature or displacement. In this regards, a computer program was developed which is the next generation of the aforesaid program with additional functionality and options. Triangulation of the section allows opportunity for cross-sectional geometry. Biaxial lateral curvature/displacement/force combined with any sequence of axial load provides opportunity to analyze the performance of a reinforced concrete column under any load and displacement path. Use of unconventional reinforcement, such as FRP, in lateral as well as longitudinal direction is another feature of this application.