Assessment of Seismic Response and Steel Jacket Retrofit of Squat Circular Reinforced Concrete Bridge Columns

Assessment of Seismic Response and Steel Jacket Retrofit of Squat Circular Reinforced Concrete Bridge Columns PDF Author: Ravindra Verma
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 448

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Assessment of Seismic Response and Steel Jacket Retrofit of Squat Circular Reinforced Concrete Bridge Columns

Assessment of Seismic Response and Steel Jacket Retrofit of Squat Circular Reinforced Concrete Bridge Columns PDF Author: Ravindra Verma
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 448

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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: 9781527527850
Category : Columns, Concrete
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.

Steel Jacketing of Circular Reinforced Concrete Bridge Columns for Enhanced Flexural Performance

Steel Jacketing of Circular Reinforced Concrete Bridge Columns for Enhanced Flexural Performance PDF Author: Yuk Hon Chai
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 594

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Seismic Retrofit of Circular Reinforced Concrete Bridge Columns

Seismic Retrofit of Circular Reinforced Concrete Bridge Columns PDF Author:
Publisher:
ISBN: 9780921303152
Category :
Languages : en
Pages : 12

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Book Description
Inadequate flexural strength and ductility or shear strength of concrete bridge columns has resulted in collapse or severe damage of a number of California bridges in recent moderate earthquakes. In general, these bridges were designed prior to the new seismic design methods which were implemented in the mid-seventies. Bridges constructed in accordance with the new design methods have performed well in recent earthquakes. However, the large number of older bridges that are in service, particularly freeway overpasses designed and constructed in the 1950s and 1970s, are now recognized to have substandard design details and to constitute a cause for major concern. This paper reports the results of a theoretical and experimental program investigating retrofit techniques for circular columns by encasing the critical regions within a steel jacket. The jacket is bonded to the column using grout. Results from six large-scale column tests show that the casing acts efficiently as confinement reinforcement, enabling a displacement ductility factor of greater than 6 to be achieved. The casing also inhibits bond failures at the laps of longitudinal reinforcement in the critical regions of the column by restraining the dilation and spalling of the cover concrete which degenerates into bond failure. Comparisons of 'as-built' and retrofitted columns are presented, and experimental strengths and ductilities are compared with analytical predictions. For the covering abstract of the Conference see IRRD Abstract no. 807839.

Seismic Shear Strength of Reinforced Concrete Columns

Seismic Shear Strength of Reinforced Concrete Columns PDF Author: M. J. N. Priestley
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 132

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Seismic Evaluation and Retrofit of Existing Reinforced Concrete Bridge Columns

Seismic Evaluation and Retrofit of Existing Reinforced Concrete Bridge Columns PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Modeled Behavior of Steel Jacket Retrofitted Reinforced Concrete Bridge Columns

Modeled Behavior of Steel Jacket Retrofitted Reinforced Concrete Bridge Columns PDF Author: Stacia Bell
Publisher:
ISBN:
Category : Earthquake engineering
Languages : en
Pages : 0

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Book Description
The aftermath of the San Fernando, Whittier, and Loma Prieta slip-strike earthquakes in 1971, 1987, and 1989, respectively, showed the inadequacy of pre-1971 reinforced concrete bridge columns and led to extensive research in the United States on seismic retrofitting of these columns. Providing steel jackets around the columns was determined to be effective in increasing lateral deformation capacity under seismic demand. The jacket can confine the concrete, such that failure occurs due to fatigue fracture of longitudinal reinforcement. Previous research did not focus specifically on behavior under long-duration subduction zone earthquakes, which can increase the likelihood of fatigue fracture relative to strike-slip earthquakes. This study focuses on behavior under demands from both strike slip and long-duration earthquakes. In this research, an analytical model of a steel jacket retrofitted reinforced concrete bridge column was developed in OpenSEES. The model consisted of a linear elastic element for the jacketed portion of the column, a fiber section to capture plasticity at the gap between the bottom of the steel jacket and top of the footing, and zero-length bond slip elements at the column-footing interface and the bottom of the jacket. The OpenSEES model was used in combination with a fatigue model to predict the fatigue failure of the longitudinal reinforcement. The column model was validated using ten test columns. This included four columns with loading protocols more reflective of strike-slip earthquakes and six columns with loading protocols reflective of long duration demands.

A Comparative Analysis of Seismic Retrofit Techniques for Reinforced Concrete Bridge Columns

A Comparative Analysis of Seismic Retrofit Techniques for Reinforced Concrete Bridge Columns PDF Author: Jacques Sarrazin
Publisher:
ISBN:
Category : University of Ottawa theses
Languages : en
Pages : 336

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Experimental Characterization of Steel Jacket Retrofitted Reinforced Concrete Bridge Column Behavior in Cascadia Subduction Zone Earthquakes

Experimental Characterization of Steel Jacket Retrofitted Reinforced Concrete Bridge Column Behavior in Cascadia Subduction Zone Earthquakes PDF Author: Sean McGuiness
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 139

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Book Description
Research on seismic retrofitting of Reinforced Concrete (RC) bridge columns in the United States (U.S.) was motivated by damage observed following the 1971 San Fernando, 1989 Loma Prieta, and 1994 Northridge earthquakes of California. The research resulted in a retrofitting procedure that consisted of installing steel jackets around RC bridge columns to enhance the lateral deformation capacity. Although the research focused on the development of this retrofit strategy for bridge columns in California, the Washington State Department of Transportation (WSDOT) implemented the program in 1991. Unlike the strike-slip faults in California, seismicity in western Washington is generally dominated by the Cascadia Subduction Zone fault. The 1964 Alaska, U.S., 2010 Maule, Chile and 2011 Tohoku, Japan are examples of mega-thrust long duration earthquakes emanating from a subduction zone fault and producing ground motions with longer durations of strong shaking than strike-slip faults. The research conducted in this study was motivated by the need to assess performance of the existing retrofit strategy when subjected to the expected demands of subduction zone earthquakes. The research conducted herein was an experimental study on the behavior of steel jacket retrofitted bridge columns subjected to demands from long duration earthquakes. Six reduced scale column specimens were designed, constructed, and tested as cantilevers. WSDOT's inventory was characterized to inform the values used for the column parameters, such that the six columns were intended to reasonably cover the range of values for critical parameters. Five of six tests utilized a modified fully reversed-cyclic lateral loading protocol to include additional cycles characteristic of long duration earthquakes. The sixth test used an earthquake protocol, obtained from the response of a single degree of freedom model to a synthetic Cascadia Subduction Zone ground motion in western Washington. Study results indicated stable drifts, including minimal pinching in the load-displacement response indicative of favorable hysteretic energy dissipation, at drifts in excess of the 4\\% expectation set forth in the steel jacket retrofit design guidelines. Total deformation was primarily a result of longitudinal reinforcement bond slip and elongation at the footing-column interface with strength degradation due to low-cycle fatigue fracture.

Flexural Retrofit of Circular Reinforced Concrete Bridge Columns by Steel Jacketing -- Experimental Studies

Flexural Retrofit of Circular Reinforced Concrete Bridge Columns by Steel Jacketing -- Experimental Studies PDF Author: Yuk Hon Chai
Publisher:
ISBN:
Category :
Languages : en
Pages :

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