Download or read book Steel Diaphragms in Prestressed Concrete Girder Bridges written by Robert Emil Abendroth and published by . This book was released on 2004 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lateral Load Resistance of Diaphragms in Prestressed Concrete Girder Bridges written by R. E. Abendroth and published by . This book was released on 1991 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Each year several prestressed concrete girder bridges in Iowa and other states are struck and damaged by vehicles with loads too high to pass under the bridge. Whether or not intermediate diaphragms play a significant role in reducing the effect of these unusual loading conditions has often been a topic of discussion. A study of the effects of the type and location of intermediate diaphragms in prestressed concrete girder bridges when the bridge girder flanges were subjected to various levels of vertical and horizontal loading was undertaken. The purpose of the research was to determine whether steel diaphragms of any conventional configuration can provide adequate protection to minimize the damage to prestressed concrete girders caused by lateral loads, similar to the protection provided by the reinforced concrete intermediate diaphragms presently being used by the Iowa Department of Transportation. The research program conducted and described in this report included the following: A comprehensive literature search and survey questionnaire were undertaken to define the state-of-the-art in the use of intermediate diaphragms in prestressed concrete girder bridges. A full scale, simple span, restressed concrete girder bridge model, containing three beams was constructed and tested with several types of intermediate diaphragms located at the one-third points of the span or at the mid-span. Analytical studies involving a three-dimensional finite element analysis model were used to provide additional information on the behavior of the experimental bridge. The performance of the bridge with no intermediate diaphragms was quite different than that with intermediate diaphragms in place. All intermediate diaphragms tested had some effect in distributing the loads to the slab and other girders, although some diaphragm types performed better than others. The research conducted has indicated that the replacement of the reinforced concrete intermediate diaphragms currently being used in Iowa with structural steel diaphragms may be possible.
Download or read book Lateral Impact Response for Prestressed Concrete Girder Bridges with Intermediate Diaphragms written by Bassem Onsi Andrawes and published by . This book was released on 2001 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: Each model was analyzed with either one RC or two different types of steel intermediate diaphragms. The bridge models were analyzed for a lateral impact load applied at different locations along the bottom flange of an exterior girder. A comparison was made between the induced strains and displacements in the girders for each diaphragm case. This study revealed that intermediate diaphragms have an effect on reducing girder damage in PC girder bridges. When a lateral impact load was applied at a diaphragm location, the RC diaphragm provided more damage protection for the girders than that provided by either of the two selected steel diaphragms. The three types of diaphragms studied essentially provided the same degree of damage protection when a lateral impact load was applied away from a diaphragm location.
Download or read book Assessing the Needs for Intermediate Diaphragms in Prestressed Concrete Bridges written by and published by . This book was released on 2008 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reinforced concrete Intermediate Diaphragms (IDs) are currently being used in prestressed concrete (PC) girder bridges in Louisiana. Some of the advantages of providing IDs are disputed in the bridge community because the use of IDs increases the cost and time of construction. There is no consistency in the practice of providing IDs among various states and codes of practice, and the overall effectiveness of IDs, as well as the need for them in prestressed concrete bridges, is unclear. The objectives of this research were (1) to assess the need of reinforced concrete (RC) IDs in PC girder bridges and to determine their effectiveness, and (2) to search for a possible alternative steel diaphragm configuration that could replace concrete diaphragms if necessary. The research team has examined and reviewed state-of-the-art technology and current practices from many sources of information on IDs. Through a survey questionnaire and review of the Louisiana Department of Transportation and Development (LADOTD) Bridge Design Manual, the research team obtained relevant information regarding the ID practices in Louisiana. Through the LADOTD data base for all state bridges, and from direct interaction with district engineers, several of the bridges that are of interest for this study were selected for field inspection. From these field trips to various bridge locations, much information has been acquired from the bridges themselves, as well as from the district engineers. Systematic parametric studies for various bridge configurations, which are representative of an entire range of bridge geometries with different parameters, were analyzed through simplified and solid finite element models. This study was performed on right and skewed bridges, which are simply supported and continuous. A reduction factor that could be multiplied by the AASHTO load distribution factor to account for the influence of the diaphragm in load distribution was developed. A finite element analysis was carried out using 3-D solid models to assess the effectiveness of various diaphragms in protecting the girders against the lateral impact and to determine the design forces in the steel bracing members during construction of deck. The results from the parametric studies indicated that several parameters such as skew, span length, spacing, stiffness of diaphragm and girder have different levels of influence on the effectiveness of diaphragms in live load distribution for bridges. Correction factors that could quantify the ID influence on load distribution were developed. Results from various studies indicated that a steel diaphragm section can possibly replace the RC diaphragms. A prestressed concrete bridge was tested in the field. This bridge was selected by an inspection team comprised of personnel from FHWA, LADOTD, and the LSU research team and is located over Cypress Bayou on LA 408 East, in District 61. A comprehensive instrumentation and loading scheme is presented and illustrated in this report. The instrumentation consists of LVDTs - Linear Variable Differential Transformers (to measure the midspan deflection of each girder), accelerometers, strain gauges, and acoustic emission sensors. The measured results are presented, and comparisons are made between the finite element model and the field tests.
Download or read book Lateral Load Resistance of Diaphragms in Prestressed Concrete Girder Bridges written by Mark Wayne Shafer and published by . This book was released on 1994 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lateral load resistance of diaphragms in prestressed concrete girder bridges written by and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Intermediate Diaphragms to Prestressed Concrete Bridge Girders in Over height Truck Impacts written by Pizhong Qiao and published by . This book was released on 2008 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Diaphragms in Prestressed Concrete Girder and Slab Bridges written by S. Sengupta and published by . This book was released on 1973 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cross frame Diaphragm Bracing of Steel Bridge Girders written by W. M. Kim Roddis and published by . This book was released on 2008 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: Steel plate girder bridges make use of traditional cross-frame diaphragms to stabilize the compression flange of girders. These braces are required during construction, especially during deck placement, to prevent lateral torsional buckling of bridge girders. Girder buckling capacity is a function of cross-frame diaphragm spacing as well as strength and stiffness. Recent developments in bridge design may cause the governing girder limit state to shift from one of strength to one of stability. These developments include the elimination of in-plan bracing, composite girders, High Performance Steels, and phased deck replacements. In addition, the American Association of State Highway and Transportation Officials (AASHTO) has changed its code requirement for cross-frame diaphragm spacing in the 1998 AASHTO LRFD Bridge Design Specifications. The requirement for 25-foot maximum brace spacing has been removed. The current requirement is for a "rational analysis" to determine cross-frame diaphragm spacing. Explanations of the problems these changes cause in design are discussed. A case study is presented of a bridge that suffered construction difficulties during deck placement. This investigation found that the cross-frame diaphragms were not stiff enough to brace the plate girders during the deck placement. Suggestions are given as to an efficient, economical design and spacing for cross-frame diaphragms on plate girder bridges.
Download or read book Effect of Diaphragms in Skew Prestressed Concrete Box Girder Bridges microform written by Gamal Abdel-Aziz Mohamed Ghoneim and published by National Library of Canada. This book was released on 1986 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Design Procedure for Intermediate External Diaphragms on Curved Steel Trapezoidal Box Girder Bridges written by Matthew Alex Memberg and published by . This book was released on 2002 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Continuity Diaphragm for Skewed Continuous Span Precast Prestressed Concrete Girder Bridges written by and published by . This book was released on 2004 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Barrier Joint and Diaphragm Effects on Force Distribution in Prestressed Concrete Girder Bridges written by Jonathan Darren Chipperfield and published by . This book was released on 2010 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: The purpose of this research was to create two finite element models (FEM) using ANSYS 11.0 and calibrate them to the measured test results. After the calibrated models were validated a parametric study was performed comparing the effects of secondary elements on live load distribution. Included in this parametric study are the effects of the barrier, the barrier joint, and the diaphragms, on the girders, both interior and exterior. The results of this project show the effects of secondary elements and whether they are localized or global on the longitudinal span of the bridge, as well as tell how the live load is being distributed. Also, for load testing, recommendations on placement of strain gages will be discussed.
Download or read book Prestressed Concrete Bridges written by Christian Menn and published by Birkhäuser. This book was released on 2012-12-06 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book was written to make the material presented in my book, Stahlbetonbrucken, accessible to a larger number of engineers throughout the world. A work in English, the logical choice for this task, had been contemplated as Stahlbetonbrucken was still in its earliest stages of preparation. The early success of Stahlbetonbrucken provided significant impetus for the writing of Prestressed Concrete Bridges, which began soon after the publication of its predecessor. The present work is more than a mere translation of Stahlbetonbrucken. Errors in Stahlbetonbrucken that were detected after publication have been corrected. New material on the relation between cracking in concrete and corrosion of reinforce ment, prestressing with unbonded tendons, skew-girder bridges, and cable-stayed bridges has been added. Most importantly, however, the presentation of the material has been extensively reworked to improve clarity and consistency. Prestressed Concrete Bridges can thus be regarded as a thoroughly new and improved edition of its predecessor.
Download or read book Effects of Diaphragms in Bridges with Prestressed Concrete I section Girders written by S. Sithichaikasem and published by . This book was released on 1972 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
