Download or read book Live Load Distribution on Longitudinal Glued laminated Timber Girder Bridges written by and published by . This book was released on 2011 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increased use of timber bridges in the U.S. transportation system has required additional research to improve the current design methodology of these bridges. For this reason, the U.S. Forest Service, Forest Products Laboratory (FPL), and the Federal Highway Administration have supported several research programs to attain the objective listed above. This report is a result of a study sponsored by the FPL, with the objective of determining how highway truckloads are distributed to girders of a glued-laminated timber bridge. The American Association of State Highway and Transportation Official (AASHTO) load and resistance factor design (LRFD) Bridge Design Specification provides live-load distribution provisions for glued-laminated girder timber bridges that were used in previous AASHTO Specifications. The AASHTO live-load distribution provisions were reviewed in this report. Field-test results were used to review the current AASHTO LRFD glued-laminated timber girder bridge-design specifications and to validate analytical results obtained by finite-element analyses. With the validated analytical models, parametric studies were performed to determine the worst-case live-load distribution factors that can be used to calculate the design moment and shear for glued-laminated timber girders. Simplified live-load distribution equations that can be used to determine these distribution factors were developed and are provided in this report. These equations take into account how load is distributed to the bridge girders, considering the effects of span length, girder spacing, and clear width of the bridge.
Download or read book Live load Distribution on Glued laminated Timber Girder Bridges written by and published by . This book was released on 2011 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increased use of timber bridges in the U.S. transportation system has required additional research to improve the current design methodology of these bridges. For this reason, the U.S. Forest Service, Forest Products Laboratory (FPL), and the Federal Highway Administration have supported several research programs to attain the objective listed above. This report is a result of a study sponsored by the FPL, with the objective of determining how highway truckloads are distributed to girders of a glued-laminated timber bridge. The American Association of State Highway and Transportation Official (AASHTO) load and resistance factor design (LRFD) Bridge Design Specification provides live-load distribution provisions for glued-laminated girder timber bridges that were used in previous AASHTO Specifications. The AASHTO live-load distribution provisions were reviewed in this report. Field-test results were used to review the current AASHTO LRFD glued-laminated timber girder bridge-design specifications and to validate analytical results obtained by finite-element analyses. With the validated analytical models, parametric studies were performed to determine the worst-case live-load distribution factors that can be used to calculate the design moment and shear for glued-laminated timber girders. Simplified live-load distribution equations that can be used to determine these distribution factors were developed and are provided in this report. These equations take into account how load is distributed to the bridge girders, considering the effects of span length, girder spacing, and clear width of the bridge.
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 Load Distribution in Glued Laminated Longitudinal Timber Deck Highway Bridges written by Wallace Wolfred Sanders and published by . This book was released on 1985 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Live Load Distribution on Longitudinal Glued laminated Timber Deck Bridges written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Timber Bridges written by Michael A. Ritter and published by . This book was released on 1990 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Live Load Deflection Criteria for Glued laminated Timber Bridges written by Travis Kent Hosteng and published by . This book was released on 2004 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to promote and increase the use of timber bridges in our nations transportation systems, the United States Department of Agriculture (USDA) and the Forest Products Laboratory funded research to develop design criteria to improve the design of glued-laminated timber bridges. This project is part of this research and is directed towards developing, and/or making recommendations for, acceptable live load deflection criteria, which are based on the actual structural performance of these types of bridges. Specifically, the relationship between live load deflection and the condition of the asphalt wearing surface is of particular interest. To accomplish this, eight glued-laminated timber girder bridges and four longitudinal glued-laminated timber deck bridges were selected for testing. The performance of the bridges was investigated under live loading and analyzed in conjunction with the condition of the wearing surfaces gathered from field inspections. Testing involved loading the structures with fully loaded tandem axle dump trucks and gathering global and differential deflection data. Field tests revealed that the majority of the asphalt wearing surface deterioration was primarily the result of differential deflections.
Download or read book Single Lane Live Load Distribution Factor for Decked Precast prestressed Concrete Girder Bridges written by John Zhongguo and published by . This book was released on 2005 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: The live load distribution factor (DF) equations provided by AASHTO-LRFD for the decked precast/prestressed concrete (DPPC) girder bridge system do not differentiate between a single or multilane loaded condition. This practice results in a single lane load rating penalty for DPPC girder bridges. The objective of this project is to determine DF equations which accurately predict the distribution factor of the DPPC girder bridge system when it is only subjected to single lane loading. Eight DPPC girder bridges were instrumented. Each bridge was loaded with a single load vehicle to simulate the single lane loaded condition. The experimental data was used to calibrate 3D FE models and 2D grillage models of the DPPC girder bridge system. The calibrated models were used to conduct a parametric study of the DPPC girder bridge system subjected to a single lane loaded condition. Two sets of new equations that describe the single lane loaded distribution factor for both shear and moment forces of these bridges are proposed and compared with AASHTOLRFD DF equations.
Download or read book Standard Plans for Timber Bridge Superstructures written by James P. Wacker and published by . This book was released on 2001 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: These standardized bridge plans are for superstructures consisting of treated timber. Seven superstructure types are included: five longitudinal and two transverse deck systems. Both HS20 and HS25 loadings are included, along with L/360 and L/500 deflection criteria.
Download or read book Timber Bridges written by Michael A. Ritter and published by Datamotion Publishing LLC. This book was released on 1990 with total page 916 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents a comprehensive analysis of the design, construction, inspection, and maintenance of timber bridges.
Download or read book Timber Bridges written by National Research Council (U.S.). Transportation Research Board and published by Transportation Research Board National Research. This book was released on 1986 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Standard Specifications for Highway Bridges written by American Association of State Highway and Transportation Officials and published by AASHTO. This book was released on 2002 with total page 1054 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation of the Load Distribution on a Timber Deck steel Girder Bridge written by Marvin Henry Hilton and published by . This book was released on 1975 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: The load distribution on a 48.5-ft. span timber deck-steel girder bridge built to the Virginia Department of Highways and Transportation standard SS-4 requirements was investigated under two conditions. The first condition was concerned with the load distribution when the timber deck fasteners were tight and the second condition involved investigating the load distribution when the fasteners were loosened in several stages. The results of the study indicated that the live load stresses were of the same general order of magnitude and that the lateral load distribution was generally the same whether the deck plank fasteners were loose or tight. The load distribution factor currently used for the interior girders was found to be too high, whereas the procedure used for distribution of the load to the exterior girders was slightly low. It is recommended that consideration be given to using a load distribution factor of S for the evaluation of both the interior and exterior girders of timber deck-steel girder bridges similar to the one investigated. Compared to current procedures, this modification would result in a 20% reduction in the live load distribution to the interior girders and a 28% increase in the distribution to the exterior girders.
Download or read book Finite Analysis of Glued laminated Timber Girder Bridges written by Hanil Cha and published by . This book was released on 2004 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: A user friendly preprocessor to the ANSYS software was developed and used to model glulam girder bridges for finite element analysis. The program requires input data such as bridge dimensions, material properties, load, and load positions for analyzing the bridge. Five modeling options to idealize the connection between the bridge deck and the bridge girder are available in the developed program. The program also allows the user to model the bridge support conditions to account for end restraints. Shell elements were used to model the bridge deck while beam or shell elements can be utilized to model the bridge girders. Several output files that contain deflection, stress, and strain contours in the deck or girders are also generated during the analysis process. The file containing the deflection results can also be imported into the Excel software and be used to represent the results in a graphical format. Eight bridges with available experimental data were analyzed to calibrate finite elements results. A study was first conducted to investigate the sensitivity of the finite element results to the modeling technique, a slight change in the material properties, and the end conditions. The analytical results were generally in agreement with the experimental results. In addition, the analysis showed that the idealization of the support condition has a significant effect on the results.
Download or read book AASHTO LRFD Bridge Design Specifications written by American Association of State Highway and Transportation Officials and published by . This book was released on 1994 with total page 1134 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The provisions of these Specifications are intended for the design, evaluation and rehabilitation of both fixed and movable highway bridges. Mechanical, electrical, and special vehicular and pedestrian safety aspects of movable bridges, however, are not covered. Provisions are not included for bridges used solely for railway, rail transit or public utilities. For bridges not fully covered herein, the provisions of these Specifications mat be applied, as augmented with additional design criteria where required. These specifications are not intended to supplant proper training or the exercise of judgment by the Designer, and state only the minimum requirements necessary to provide for public safety. The Owner or the Designer may require the sophistication of design or the quality of materials and construction to be higher than the minimum requirements. The concept of safety through redundancy and ductility, and protection against scour and collision are emphasized. The design provisions of these Specifications employ the Load and Resistance Factor Design, LRFD, methodology. The factors have been developed from the theory of reliability based upon current statistical knowledge of loads and structural performance. Methods of analysis, other than those included in previous Specifications, and the modelling techniques inherent in them are included, and their use is encouraged. The commentary is not intended to provide a complete historical background concerning the development of these, or previous Specifications, nor is it intended to provide a detailed summary of the studies and research data reviewed in formulating the provisions of the Specification. However, references to some of the research data are provided for those who wish to study the background material in depth. The commentary directs attention to other documents that provide suggestions for carrying out the requirements and intent of these Specifications. However, those documents and this commentary are not intended to be a part of these Specifications."--Page1-1.
Download or read book Structural Design in Wood written by Judith J. Stalnaker and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 439 pages. Available in PDF, EPUB and Kindle. Book excerpt: Why another textbook on the design of wood sets this book apart is its inclusion of "struc structures? In many years of teaching structural tural planning. " Most textbooks show only the design in wood, the authors have used virtually selection of member proportions or number of every textbook available, as well as using only connectors in a joint to satisfy a given, com a code and no textbook at all. The textbooks pletely defined situation. This book, on the used have included both the old and the rela other hand, shows the thinking process needed tively modem; some have been fairly good, but to determine whether or not the member is re in our opinion each has deficiencies. Some quired in the first place. Following this, the books have too few solved examples. Others spacing and continuity of the member are de omit important material or have an arrange cided, its loads are determined, and finally its ment making them difficult to use as formal shape and size are selected. teaching tools. By writing this book, we intend We believe that illustrating structural plan to correct such deficiencies. ning as well as detailed member and connec The prime purpose of this book is to serve as tion design is of considerable value in helping a classroom text for the engineering or archi the student make the transition from the often tecture student.
Download or read book Live Load Spectra for Girder Bridges written by Hani Hamad Nassif and published by . This book was released on 1993 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt:
