Download or read book Evaluation of Live load Distribution Factors LLDFs of Next Beam Bridges written by Abhijeet Kumar Singh and published by . This book was released on 2012 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new precast-prestressed cross section was recently developed by a consortium of engineers from the six New England states, New York and members of the northeast region of PCI. The northeast extreme Tee (NEXT) beam is efficient for medium Bridge spans (50 to 80 ft long). Field formwork savings are introduced by having a flange cast integrally during fabrication of the beams at the precasting plant. Job safety is increased because a working platform is created. The flange width of the NEXT Beams can be adjusted during fabrication to accommodate roadways of different widths and skew angles. Because the section is new with complexity in its shape, the present design guidance cannot be used to evaluate LLDFs for NEXT beams within the context of the AASHTO LRFD. In particular, the use of live-load distribution factors (LLDFs) equations in LRFD for NEXT beams is not straightforward. The distance between the beam webs is variable depending on whether it is measured within a beam module or between adjacent modules. In absence of detailed information a PCI technical committee evaluated LLDFs (through AASHTO 2010 Bridge specification) for the NEXT beams used in the Brimfield Bridge by two different approaches and found one of them conservative. The conservative approach was single stem which uses the average spacing (between webs ([S1+S3]/2)) for use in the LLDF equations. The committee expressed concerns about whether trends of LLDFs would be similar for other parametric sets, and would like to standardize the methodology for the Bridge projects in Massachusetts with NEXT beam as the girder. To verify the conservativeness of single stem methodology (for the evaluation of LLDFs) for other parameters this research project was initiated. LLDFs are evaluated based on the two approaches and compared with the LLDFs obtained through finite element modeling. The results of 40-3D finite element models have been used to compare the LLDFs obtained from AASHTO 2010 Bridge design specification. The results were also used to compare different parameters that affect LLDFs of NEXT beams including span, skew angle, and beam end fixity. The finite element models were created using a Bridge prototype that is being instrumented for future field verification of the analyses. The models were created using frame elements for the beams and shell elements for the cast in place deck. The integral abutment and foundation of the Bridges was included in the models in which piles are created using frame elements and abutments are created using shell elements. The results indicate that the approach taken for the design of NEXT beams is in general conservative for interior girders of the Bridge. On the contrary such the adopted approach was not yielding the higher value of LLDFs. The variation in strains due to losses are compared by two methods (strains variation obtained from field data and strain variation obtained based on AASHTO equation of losses) to verify the AASHTO equation of losses.
Download or read book Pilot Study of Live Load Distribution Factors for Double Cell Adjacent Box Beam Bridges written by John A. Rautzahn and published by . This book was released on 1997 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Challenges in Mechanics of Time Dependent Materials Volume 2 written by Alex Arzoumanidis and published by Springer. This book was released on 2018-08-09 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: Challenges in Mechanics of Time-Dependent Materials, Volume 2 of the Proceedings of the 2018 SEM Annual Conference& Exposition on Experimental and Applied Mechanics, the second volume of eight from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of Experimental Mechanics, including papers in the following general technical research areas: Characterization Across Length Scales Extreme Environments & Environmental Effects Soft Materials Damage, fatigue and Fracture Inhomogeneities & Interfaces Viscoelasticity Research in Progress
Download or read book Effect of Relative Flexural torsional Beam Characteristics Upon Load Distribution in Multi beam Bridges written by Daryl Eugene Young and published by . This book was released on 1993 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Calibration of Load Factors for LRFR Bridge Evaluation written by Fred Moses and published by . This book was released on 2001 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Single Lane Live Load Distribution Factor for Decked Precast written by Jason Langdon Millam and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The Alaska Department of Transportation (AKDOT) uses the decked precast, prestressed concrete bulb-tee girder for most of its bridge construction. The live load distribution factor (DF) equations provided by the American Association of State Highway and Transportation Officials (AASHTO) for the decked bulb-tee girder system do not differentiate between a single or multilane loaded condition. This practice results in a single lane load rating penalty for decked bulb-tee girder bridges. The research objective of this thesis is to determine DF simplified equations that accurately predict the distribution factor of the decked bulb-tee girder system when it is only subjected to single lane loading. Eight decked bulb-tee bridges were instrumented. Each bridge was loaded with a single load vehicle to simulate the single lane loaded condition. The experimental data were used to calibrate grillage models of the decked bulb-tee girder system. The calibrated grillage models were used to conduct a parametric study of the bulb-tee girder system subjected to single lane loaded condition. Eight new simplified equations that describe the single lane loaded distribution factor for both shear and moment forces of these bridges are developed in this thesis"--Leaf iii.
Download or read book Calibration of LRFD Bridge Design Code written by Andrzej S. Nowak and published by . This book was released on 1999 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design of Highway Bridges written by Richard M. Barker and published by John Wiley & Sons. This book was released on 2013-02-04 with total page 1194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Up-to-date coverage of bridge design and analysis revised to reflect the fifth edition of the AASHTO LRFD specifications Design of Highway Bridges, Third Edition offers detailed coverage of engineering basics for the design of short- and medium-span bridges. Revised to conform with the latest fifth edition of the American Association of State Highway and Transportation Officials (AASHTO) LRFD Bridge Design Specifications, it is an excellent engineering resource for both professionals and students. This updated edition has been reorganized throughout, spreading the material into twenty shorter, more focused chapters that make information even easier to find and navigate. It also features: Expanded coverage of computer modeling, calibration of service limit states, rigid method system analysis, and concrete shear Information on key bridge types, selection principles, and aesthetic issues Dozens of worked problems that allow techniques to be applied to real-world problems and design specifications A new color insert of bridge photographs, including examples of historical and aesthetic significance New coverage of the "green" aspects of recycled steel Selected references for further study From gaining a quick familiarity with the AASHTO LRFD specifications to seeking broader guidance on highway bridge design Design of Highway Bridges is the one-stop, ready reference that puts information at your fingertips, while also serving as an excellent study guide and reference for the U.S. Professional Engineering Examination.
Download or read book Lateral Load Distribution Factors for Military Vehicles on Multi girder Bridges written by Juan C. Piñero and published by . This book was released on 2002 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geotechnical Engineering and Sustainable Construction written by Mahdi O. Karkush and published by Springer Nature. This book was released on 2022-03-19 with total page 791 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains selected articles from the Second International Conference on Geotechnical Engineering-Iraq (ICGE-Iraq) held in Akre/Duhok/Iraq from June 22 to 23, 2021, to discuss the challenges, opportunities, and problems of geotechnical engineering in projects. Also, the conference includes modern applications in structural engineering, materials of construction, construction management, planning and design of structures, and remote sensing and surveying engineering. The ICGE-Iraq organized by the Iraqi Scientific Society of Soil Mechanics and Foundation Engineering (ISSSMFE) in cooperation with Akre Technical Institute / Duhok Polytechnic University, College of Engineering /University of Baghdad, and Civil Engineering Department/University of Technology. The book covers a wide spectrum of themes in civil engineering, including but not limited to sustainability and environmental-friendly applications. The contributing authors are academic and researchers in their respective fields from several countries. This book will provide a valuable resource for practicing engineers and researchers in the field of geotechnical engineering, structural engineering, and construction and management of projects.
Download or read book On Load Distribution Factors in Continuous Slab girder Bridges written by Jin H. Wang and published by . This book was released on 1998 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simplified Load Distribution Factor for Use in LRFD Design written by Elisa D. Sotelino and published by . This book was released on 2004-09-01 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The “S-over” equation for the load distribution factor (LDF) was first introduced in the 1930s in the AASHTO Standard. Finite element studies, however, have shown it to be unsafe in some cases and too conservative in others. In this study, a new simplified equation that is based on the AASHTO LRFD formula and does not require an iterative procedure is developed. The new simplified equation produces LDF values that are always conservative when compared to those obtained from the finite element analyses and are generally greater than the LDF obtained using AASHTO LRFD specification. Therefore, the simplified equation provides a simple yet safe specification for LDF calculation. This study also investigates the effects of secondary elements and bridge deck cracking on the LDF of bridges. The AASHTO LRFD LDF equation was developed based on elastic finite element analysis considering only primary members, i.e., the effects of secondary elements such as lateral bracing and parapets were not considered. Meanwhile, many bridges have been identified as having significant cracking in the concrete deck. Even though deck cracking is a well-known phenomenon, the significance of pre-existing cracks on the live load distribution has not yet been assessed in the literature. First, secondary elements such as diaphragms and parapet were modeled using the finite element method, and the calculated load distribution factors were compared with the code-specified values. Second, the effects of typical deck cracking and crack types that have a major effect on load distribution were identified through a number of nonlinear finite element analyses. Transverse cracking was found to not significantly influence the transverse distribution of moment. Finally, for one of the selected bridges, both concrete cracking and secondary elements are considered to invesitigate their combined effect on lateral load distribution. The increased LDF due to deck cracking is offset by the contributions from the secondary elements. The result is that the proposed simplified equation is conservative and is recommended for determination of LDF.
Download or read book Live Load Distribution Factors for Glued laminated Timber Bridges written by Jeremy James May and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bridge Analysis Simplified written by Baidar Bakht and published by McGraw-Hill Companies. This book was released on 1985 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Protocol to Evaluate and Load Rate Existing Bridges written by Maria M. Szerszen and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The project presents protocols for evaluation of existing bridges. The research involves identification of problems to be address -- for example, verification of the load distribution factors, actual live load (weight of trucks), dynamic load factors, minimum load carrying capacity, or fatigue load spectra" (page viii).
Download or read book Bridge Engineering written by Demetrios E. Tonias and published by McGraw Hill Professional. This book was released on 2007 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aimed at US audience - architects (113,000), civil engineers (228,000), and universities and colleges offering structural engineering programs. This work reflects the bridge design code changes and the newest ASCE [American Association of Civil Engineers] design methods. It uses SI units throughout for international usage.
Download or read book LRFD Guide Specifications for the Design of Pedestrian Bridges written by American Association of State Highway and Transportation Officials and published by AASHTO. This book was released on 2009 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
