Field Measurements on Skewed Semi-integral Bridge with Elastic Inclusion

Field Measurements on Skewed Semi-integral Bridge with Elastic Inclusion PDF Author: Edward J. Hoppe
Publisher:
ISBN:
Category : Bridge approaches
Languages : en
Pages : 22

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Book Description
This project was designed to enhance the Virginia Department of Transportation's expertise in the design of integral bridges, particularly as it applies to highly skewed structures. Specifically, the project involves extensive monitoring of a semi-integral (integral backwall) bridge with a 45-degree skew. Long-term, continuous monitoring of strains developed in foundation piles, earth pressures exerted on the backwall by the adjacent approach embankment, and concrete buttress reactions preventing the superstructure from rotating in the horizontal plane will be performed. Overall, 120 strain gages, 16 earth pressure cells, and 2 high-capacity load cells, interfaced with electronic dataloggers, will be used in the study. This report provides a record of work carried out from the start of construction in January 2006 to the beginning of May 2006. It specifically describes the instrumentation of the bridge. Future reports will provide an analysis of the results of the field monitoring program. The study is expected to continue for the next 2 years in order to capture the bridge's response over a wide range of climatic conditions.

Field Measurements on Skewed Semi-integral Bridge with Elastic Inclusion

Field Measurements on Skewed Semi-integral Bridge with Elastic Inclusion PDF Author: Edward J. Hoppe
Publisher:
ISBN:
Category : Bridge approaches
Languages : en
Pages : 22

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Book Description
This project was designed to enhance the Virginia Department of Transportation's expertise in the design of integral bridges, particularly as it applies to highly skewed structures. Specifically, the project involves extensive monitoring of a semi-integral (integral backwall) bridge with a 45-degree skew. Long-term, continuous monitoring of strains developed in foundation piles, earth pressures exerted on the backwall by the adjacent approach embankment, and concrete buttress reactions preventing the superstructure from rotating in the horizontal plane will be performed. Overall, 120 strain gages, 16 earth pressure cells, and 2 high-capacity load cells, interfaced with electronic dataloggers, will be used in the study. This report provides a record of work carried out from the start of construction in January 2006 to the beginning of May 2006. It specifically describes the instrumentation of the bridge. Future reports will provide an analysis of the results of the field monitoring program. The study is expected to continue for the next 2 years in order to capture the bridge's response over a wide range of climatic conditions.

Thermal Response of a Highly Skewed Integral Bridge

Thermal Response of a Highly Skewed Integral Bridge PDF Author: Edward J. Hoppe
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 0

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Book Description
The purpose of this study was to conduct a field evaluation of a highly skewed semi integral bridge in order to provide feedback regarding some of the assumptions behind the design guidelines developed by the Virginia Department of Transportation. The project was focused on the long term monitoring of a bridge on Route 18 over the Blue Spring Run in Alleghany County, Virginia. The 110 ft long, one span bridge was constructed at a 45 degree skew and with no approach slabs. It incorporated an elasticized expanded polystyrene material at the back of the integral backwall. Bridge data reflecting thermally induced displacements, loads, earth pressures, and pile strains were acquired at hourly intervals over a period of approximately 5 years. Approach elevations were also monitored. Analysis of data was used to formulate design recommendations for integral bridges in Virginia. Field results indicated that semi integral bridges can perform satisfactorily at a 45 degree skew provided some design details are modified. The relatively high skew angle resulted in a pronounced tendency of the semi integral superstructure to rotate in the horizontal plane. This rotation can generate higher than anticipated horizontal earth pressure acting on the abutment wingwall. Study recommendations include modifying the structural detail of the backwall wingwall interface to mitigate crack formation and placing the load buttress close to the acute corner of a highly skewed abutment to reduce the abutment horizontal rotation. The use of elastic inclusion at the back of the semi integral backwall resulted in the reduction of earth pressures and negligible approach settlements. The study recommendations include proposed horizontal earth pressure coefficients for design and a revised approach to calculating the required thickness of the elastic inclusion. While recommending that the existing VDOT guidelines allow an increase in the allowable skew angle from 30 degree to 45 degree for semi integral bridges, the study also proposes a field investigation of the maximum skew angle for fully integral bridges because of the inherently low stiffness associated with a single row of foundation piles. The study indicates that current VDOT guidelines can be relaxed to allow design of a wider range of jointless bridges. The implementation of integral design has been shown to reduce bridge lifetime costs because of the elimination of deck joints, which often create numerous maintenance problems.

Measurement of the Abutment Forces of a Skewed Semi-integral Bridge as a Result of Ambient Temperature Change

Measurement of the Abutment Forces of a Skewed Semi-integral Bridge as a Result of Ambient Temperature Change PDF Author: Andrew T. Metzger
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 428

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Field Study of Integral Backwall with Elastic Inclusion

Field Study of Integral Backwall with Elastic Inclusion PDF Author: Edward J. Hoppe
Publisher:
ISBN:
Category : Bridge approaches
Languages : en
Pages : 44

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Book Description
Jointless construction is considered an effective design option to reduce bridge maintenance costs and resist seismic loads. Although these attributes make the integral bridge an increasingly popular choice, soil-structure interaction issues unique to this type of design remain unresolved. Of particular concern is the excessive settlement of approach embankments, resulting from the repetitive, thermally induced cyclic movements of the superstructure. In many cases, rectifying this condition can be expensive because the integral bridge approach slab (if provided) cannot be overlaid with pavement. To address this soil-structure interaction problem, the Virginia Department of Transportation conducted a study designed to test the feasibility of using elastic inclusion at the integral backwall. The design was completed in mid-1997, and the bridge was opened to traffic in October 1999. The bridge was constructed with elasticized expanded polystyrene (EPS) attached to the backwall. The structure has been monitored continuously for 5 years. Significantly attenuated lateral earth pressures have been recorded at the backwall, and the settlement of the approach fill has been tolerable. Field data indicate that the elasticized EPS layer has been functioning effectively in allowing the superstructure to interact with the adjoining select backfill material. The use of elasticized EPS in conjunction with a well-compacted granular backfill offers a cost-effective way of minimizing settlements at bridge approaches.

Effects of Thermal Expansion on a Skewed Semi-integral Bridge

Effects of Thermal Expansion on a Skewed Semi-integral Bridge PDF Author: Christopher L. Bettinger
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 298

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Forces Exerted in the Wingwalls of Skewed Semi-integral Bridges

Forces Exerted in the Wingwalls of Skewed Semi-integral Bridges PDF Author: Eric P. Steinberg
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 90

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Book Description
In the state of Ohio, semi-integral bridges have become more popular because these bridges eliminate high maintenance joints. The girders in a semi-integral bridge are encased in a diaphragm supported on elastomeric pads that bear on the abutment. Movement of the diaphragm caused by thermal change is theoretically resisted by backfill and also by the wingwalls for skewed bridges. The wingwalls are subjected to forces as a skewed bridge rotates during thermal expansion.

Forces in Wingwalls from Thermal Expansion of Skewed Semi-integral Bridges

Forces in Wingwalls from Thermal Expansion of Skewed Semi-integral Bridges PDF Author: Eric P. Steinberg
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 87

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Book Description
Jointless bridges, such as semi-integral and integral bridges, have become more popular in recent years because of their simplicity in the construction and the elimination of high costs related to joint maintenance. Prior research has shown that skewed semi-integral bridges tend to expand and rotate as the ambient air temperature increases through the season. As a result of the bridge movement, forces are generated and transferred to the wingwalls of the bridge. ODOT does not currently have a procedure to determine the forces generated in the wingwalls from the thermal expansion and rotation of skewed semi-integral bridges. In this study, two semi-integral bridges with skews were instrumented and monitored for behavior at the interface of the bridge's diaphragm and wingwall. A parametric analysis was also performed to determine the effects of different spans and bridge lengths on he magnitude of the forces. Based on the field results from the study it is recommended for the design of the wingwalls turned to run nearly parallel with the longitudinal axis of skewed semi-integral bridges should include a 100 psi loading at the wingwall/diaphragm interface from the thermal expansion of the bridge. In addition, analytical evaluations showed that longer spans and higher skews than allowed by ODOT's BDM could be used. However, additional considerations for larger movements and stresses generated at the wingwall/diaphragm interface would need to be considered in designs. Finally, bearing retainers in diaphragms, if used, require adequate cover to avoid spalling of concrete.

LRFD Guide Specifications for the Design of Pedestrian Bridges

LRFD Guide Specifications for the Design of Pedestrian Bridges PDF Author: American Association of State Highway and Transportation Officials
Publisher: AASHTO
ISBN: 1560514698
Category : Bridges
Languages : en
Pages : 38

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Engineering for Structural Stability in Bridge Construction

Engineering for Structural Stability in Bridge Construction PDF Author: Federal Highway Federal Highway Administration
Publisher:
ISBN:
Category :
Languages : en
Pages : 669

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Book Description
This manual is intended to serve as a reference. It will provide technical information which will enable Manual users to perform the following activities:Describe typical erection practices for girder bridge superstructures and recognize critical construction stagesDiscuss typical practices for evaluating structural stability of girder bridge superstructures during early stages of erection and throughout bridge constructionExplain the basic concepts of stability and why it is important in bridge erection* Explain common techniques for performing advanced stability analysis along with their advantages and limitationsDescribe how differing construction sequences effect superstructure stabilityBe able to select appropriate loads, load combinations, and load factors for use in analyzing superstructure components during constructionBe able to analyze bridge members at various stages of erection* Develop erection plans that are safe and economical, and know what information is required and should be a part of those plansDescribe the differences between local, member and global (system) stability

Applied Mechanics Reviews

Applied Mechanics Reviews PDF Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 338

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Book Description