Download or read book Passive Force on Skewed Bridge Abutments with Reinforced Concrete Wingwalls Based on Large scale Tests written by Kyle M. Smith and published by . This book was released on 2014 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comparison of passive force per unit width suggests that MSE wall abutments provide 60% more passive resistance per unit width compared to reinforced concrete wingwall and unconfined abutment geometries at zero skew. These findings suggest that changes should be made to current codes and practices to properly account for skew angle in bridge design.

Download or read book Evaluation of Passive Force on Skewed Bridge Abutments with Large scale Tests written by Aaron Kirt Marsh and published by . This book was released on 2013 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accounting for seismic forces and thermal expansion in bridge design requires an accurate passive force versus backwall deflection relationship. Current design codes make no allowances for skew effects on the development of the passive force. However, small-scale experimental results and available numerical models indicate that there is a significant reduction in peak passive force as skew angle increases for plane-strain cases. To further explore this issue large-scale field tests were conducted at skew angles of 0°, 15°, and 30° with unconfined backfill geometry. The abutment backwall was 11 feet (3.35-m) wide by 5.5 feet (1.68-m) high, and backfill material consisted of dense compacted sand. The peak passive force for the 15° and 30° tests was found to be 73% and 58%, respectively, of the peak passive force for the 0° test which is in good agreement with the small-scale laboratory tests and numerical model results. However, the small differences may suggest that backfill properties (e.g. geometry and density) may have some slight effect on the reduction in peak passive force with respect to skew angle. Longitudinal displacement of the backfill at the peak passive force was found to be approximately 3% of the backfill height for all field tests and is consistent with previously reported values for large-scale passive force-deflection tests, though skew angle may slightly reduce the deflection necessary to reach backfill failure. The backfill failure mechanism appears to transition from a log spiral type failure mechanism where Prandtl and Rankine failure zones develop at low skew angles, to a failure mechanism where a Prandtl failure zone does not develop as skew angle increases.

Download or read book Evaluation of Passive Force on Skewed Bridge Abutments with Controlled Low strength Material Backfill written by Kevin Bjorn Wagstaff and published by . This book was released on 2016 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: To determine the relationship of passive force versus backwall displacement for a CLSM backfilled bridge abutment, two laboratory large-scale lateral load tests were conducted at skew angles of 0 and 30°. The model backwall was a 4.13 ft (1.26 m) wide and 2 ft (0.61 m) tall reinforced concrete block skewed to either 0 or 30°. The passive force-displacement curves for the two tests were hyperbolic in shape, and the displacement required to reach the peak passive resistance was approximately 0.75-2% of the wall height. The effect of skew angle on the magnitude of passive resistance in the CLSM backfill was much less significant than for conventional backfill materials. However, within displacements of 4-5% of the backwall height, the passive force-displacement curve reached a relatively constant residual or ultimate strength. The residual strength ranged from 20-40% of the measured peak passive resistance. The failure plane did not follow the logarithmic spiral pattern as the conventional backfill materials did. Instead, the failure plane was nearly linear and the failed wedge was displaced more like a block with very low compressive strains.

Download or read book Large scale Testing of Passive Force Behavior for Skewed Abutments with High Width height Ratios written by Katie Noel Palmer and published by . This book was released on 2013 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of seismic forces and thermal expansion on bridge performance necessitate an accurate understanding of the relationship between passive force and backwall deflection. In past case studies, skewed bridges exhibited significantly more damage than non-skewed bridges. These findings prompted studies involving numerical modeling, lab-scales tests, and large-scale tests that each showed a dramatic reduction in passive force with increased skew. Using these results, a correlation was developed between peak passive force and backwall skew angle. The majority of these tests had length to height ratios of 2.0; however, for several abutments in the field, the length to height ratio might be considerably higher than 2.0. This change in geometry could potentially affect the validity of the previously found passive force reduction correlation.

Download or read book Numerical Analysis of Passive Force on Skewed Bridge Abutments with Reinforced Concrete Wingwalls written by Scott Karl Snow and published by . This book was released on 2019 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: The finite element models generally confirmed the findings of Smith (2014). The results of the 11- and 38-foot abutment finite element models confirmed that the wingwall on the obtuse side of the 45° skewed abutments experienced approximately 4 to 5 times the amount of horizontal soil pressure and 5 times the amount of bending moment compared to the non-skewed abutment. Increases in the pressures and bending moments are likely caused by soil confined between the obtuse side of the abutment and the wingwall.

Download or read book Large scale Testing of Low strength Cellular Concrete for Skewed Bridge Abutments written by Rebecca Eileen Black and published by . This book was released on 2018 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cellular concrete for the 0° skew test had an average wet destiny of 29 pounds per cubic food and a 28-day compressive strength of 120 pounds per square inch. The cellular concrete for the 30° skew test had an average wet density of 31 pounds per cubic foot and a 28-day compressive strength of 132 pounds per square inch. It was observed from the passive force deflection curves of the two tests that skew decreased the peak passive resistance by 29% , from 52.1 kips to 37 kips. Various methods were used to predict the peak passive resistance and compared with observed behavior to verify the validity of each method.

Download or read book Large scale Testing of Passive Force Behavior for Skewed Bridge Abutments with Gravel and Geosynthetic Reinforced Soil GRS Backfills written by Amy Fredrickson and published by . This book was released on 2015 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Test results in both sets of backfills confirmed previous findings that there is significant reduction in passive force with skewed abutment configurations. The reduction factor was 0.58 for the gravel backfill and 0.63 for the GRS backfill, compared to the predicted reduction factor of 0.53 for a 30° skew. These results are within the scatter of previous skewed testing, but could indicate that slightly higher reduction factors may be applicable for gravel backfills.

Download or read book Evaluation of Passive Force Behavior for Bridge Abutments Using Large scale Tests with Various Backfill Geometries written by Jaycee Cornwall Smith and published by . This book was released on 2014 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge abutments are designed to withstand lateral pressures from thermal expansion and seismic forces. Current design curves have been seen to dangerously over- and under-estimate the peak passive resistance and corresponding deflection of abutment backfills. Similar studies on passive pressure have shown that passive resistance changes with different types of constructed backfills. The effects of changing the length to width ratio, or including MSE wingwalls determine passive force-deflection relationships. The purpose of this study is to determine the effects of the wall heights and of the MSE support on passive pressure and backfill failure, and to compare the field results with various predictive methods.

Download or read book Large scale Testing of Low strength Cellular Concrete for Skewed Bridge Abutments written by Tyler Kirk Remund and published by . This book was released on 2017 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: It was observed that the cellular concrete backfill mainly compressed under loading with no visible failure at the surface. The passive-force curves showed the material reaching an initial peak resistance after movement equal to 1.7-2.6% of the backwall height and then remaining near this strength or increasing in strength with any further deflection. No skew effects were observed; any difference between the two tests is most likely due to the difference in concrete placement and testing.

Download or read book Passive Force deflection Behavior for Abutments with MSE Confined Approach Fills written by Kyle M. Rollins and published by . This book was released on 2010 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: Approach fills behind bridge abutments are commonly supported by wrap-around mechanically stabilized earth (MSE) walls; however the effect of this geometry on passive force development is unknown. This report describes the first large-scale tests to evaluate passive force-deflection curves for abutments with MSE wingwalls. A test was also performed with fill extending beyond the edge of the abutment wall for comparison. The abutment wall was simulated with a pile supported cap 5.5 ft high, 11 ft wide, and 15 ft long in the direction of loading. The backfill behind the pile cap consisted of clean sand compacted to 96% of the modified Proctor maximum density. As the pile cap was loaded laterally, pressure on the MSE wall led to pull-out of the steel reinforcing grids and the MSE wall panels moved outward about 2% of the wall height when the ultimate passive force developed. Despite pullout, the passive force per effective width was 28 kips/ft for the pile cap with MSE wingwalls compared to 22.5 kips/ft for the cap without wingwalls. Nevertheless, the passive force with the MSE wingwalls was still only 76% of the resistance provided by the cap with fill extending beyond the edges. The pile cap with MSE walls required greater movement to reach the ultimate passive force (deflection of 4.2% of wall height vs. 3%). The Caltrans method provided good agreement with the measured passive resistance while the log spiral method required the use of a higher plane strain friction angle to provide reasonable agreement.

Download or read book Numerical Analysis of Passive Force on Skewed Bridge Abutments written by Zifan Guo and published by . This book was released on 2015 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results were particularly sensitive to the soil friction angle, wall friction angle, angle of dilatancy, soil stiffness and lateral restraint of the abutment backwall movement.

Download or read book Large Scale Bridge Abutment Tests to Determine Stiffness and Ultimate Strength Under Seismic Loading written by Brian H. Maroney and published by . This book was released on 1995 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Concrete International written by and published by . This book was released on 1992 with total page 1198 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design and Construction of Bridge Approaches written by Harvey E. Wahls and published by Transportation Research Board. This book was released on 1990 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes case histories of the Dumbarton Bridge (San Francisco Bay, Calif.), the Rainier Avenue Embankment (Seattle, Wash.) and the Gallows Road Grade Separation (Fairfax, Va.)

Download or read book Bridge Engineering Handbook written by Wai-Fah Chen and published by CRC Press. This book was released on 2019-09-11 with total page 690 pages. Available in PDF, EPUB and Kindle. Book excerpt: First Published in 1999: The Bridge Engineering Handbook is a unique, comprehensive, and state-of-the-art reference work and resource book covering the major areas of bridge engineering with the theme "bridge to the 21st century."

Download or read book Integrated Probabilistic Performance based Evaluation of Benchmark Reinforced Concrete Bridges written by Kevin Rory Mackie and published by . This book was released on 2008 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismic Design and Retrofit of Bridges written by M. J. N. Priestley and published by John Wiley & Sons. This book was released on 1996-04-12 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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