Download or read book Uniform Temperature Predictions and Temperature Gradient Effects on I Girder and Box Girder Concrete Bridges written by Edyson Rojas and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to more accurately quantify the behavior and degradation of bridges throughout their service life, the Federal Highway Administration lunched the Long-Term Bridge Performance Program. As part of this program an I-girder, integral abutment bridge near Perry, Utah and a two span, box-girder bridge south of Sacramento, California were instrumented with foil strain gauges, velocity transducers, vibrating wire strain gauges, thermocouples, and tilt meters. In this research study, data from the thermocouples was used to calculate average bridge temperature and compare it to the recommended design criteria in accordance to the 2010 LRFD Bridge Design Specifications of the American Association of State Highway and Transportation Officials (AASHTO). The design maximum average bridge temperature defined in the 2010 LRFD Bridge Design Specifications was exceeded for both bridges. The accuracy of the 1991 Kuppa Method and the 1976 Black and Emerson Method to estimate the average bridge temperature based on ambient temperature was studied and a new method that was found to be more accurate was proposed. Long-term predictions of average bridge temperature for both bridges were calculated. Temperature gradients were measured and compared to the 2010 AASHTO LRFD Bridge Design Specifications and the 1978 Priestley Method. Calculated flexural stresses as a function of maximum positive and negative temperature gradients were found to exceed the service limit state established in the 2010 AASHTO LRFD Bridge Design Specifications in the case of the California bridge.
Download or read book Effects of Transverse Temperature Gradients on Bridges written by and published by . This book was released on 1971 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal gradients and their effects on segmental concrete box girder bridges written by Bryan Alan Wood and published by . This book was released on 1997 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Gradients in Southwestern United States and the Effect on Bridge Bearing Loads written by Leanne White and published by . This book was released on 2017 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Thermal gradients became a component of bridge design after soffit cracking in prestressed concrete bridges was attributed to nonlinear temperature distribution through the depth of the bridge. While the effect of thermal gradient on stress distributions has been previously investigated in concrete bridges, less research has been done investigating the effect on bearing loads. The climate condition of the southwestern portion of the United States may cause larger thermal gradients than recommended by AASHTO LRFD Bridge Design Specifications. The main objective of this study was to evaluate the effect of thermal gradients in the southwestern region of the United States on bearing design. This study consisted of two parts, heat flow analysis using long-term meteorological data and two case study bridges in Nevada analyzed for bearing loadings including several variations of thermal gradient loading. One bridge was a two-span concrete posttensioned box girder bridge in Las Vegas, the second bridge was a two-span composite steel girder bridge in Reno. [...] Variation of constant temperature through the steel girder influenced both longitudinal and transverse loading. Reducing the temperature through the girder maximized bending moment and support reactions, while unaltered temperature through the girder maximized individual bearing loads. Thus, it is uncertain whether constant temperature through girder should be included."--Abstract
Download or read book Thermal Effects in Concrete Bridge Superstructures written by Roy A. Imbsen and published by Transportation Research Board National Research. This book was released on 1985 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Temperature Gradients for Concrete Bridge Design written by and published by . This book was released on 1990 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The diurnal changes in environment cause non-uniform temperature distribution in concrete bridges. This effect is not easy to analyze and frequently is treated in a simplified way. In the past few years, some reported cases of bridge damage have been associated with thermal effects. To analyze these problems, a numerical technique, based on the resolution of the Fourier equation, is presented. By using this method a parametric study was undertaken to evaluate the thermal gradients to be considered in design, for typical concrete bridge sections. This technique was also applied to the analysis of special cases where an accurate estimation of thermal effects is necessary. Three examples are presented, related to the study of the evolution of heat of gradients in different elements of the same bridge. For the covering abstract of the Conference see IRRD Abstract no. 807839.
Download or read book Monitoring Interpreting and Predicting Temperature Effects in Concrete Box Girder Bridges written by Hazel A. McDonald and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Indications about Thermal Gradient Magnitudes from Field Studies of Concrete Box Girder Bridges written by and published by . This book was released on 1998 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Effects in Concrete Box Girder Bridges written by and published by . This book was released on 1976 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Short and Long Term Effects of Temperature and Strain on a Concrete Bulb Tree Girder Bridge written by Ethan Pickett and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Utah Transportation Center (UTC) as well as the Mountain Plains Consortium, sponsored a study to investigate the long-term performance of a deck bulb tee girder bridge. The bridge in question is located in Nibley, Utah and was erected in early 2016. Temperature and prestress losses were analyzed from embedded instrumentation placed within two of the bridge girders before casting. These two girders contained a total of 50 thermocouples and 16 vibrating wire strain gauges. These instruments were placed at the mid-span and end of an exterior girder and the mid-span, quarter-span, and end of a center girder in order to effectively monitor the bridge response in one quarter of the bridge superstructure. The monitoring performed with the thermocouples included the temperature of the girders during curing, weekly maximum and minimum temperatures compared to methods for predicting the average bridge temperature, maximum and minimum thermal gradients at each of the five selected cross sections compared to Code thermal gradients, and thermal camber by measured temperature compared to models to predict thermal gradients. The 16 strain gauges measured prestress losses at four girder cross-sections, which were compared to two predictive methods provided by AASHTO as well as a method by PCI. An additional comparison of the equations provided by AASHTO and a newly available equation used for determining the modulus of elasticity of concretes with a compressive strength of 6,000 - 12,000 psi was performed. Additional exterior instrumentation were provided by Bridge Diagnostics Inc. (BDI) in order to monitor short-term changes within the bridge. A total of 8 strain gauges were attached to the exterior of the girders with 6 attached at the bottom face of 6 girders and 2 attached at the centroid of 2 girders. These sensors as well as the software and wireless data acquisition provided a method to measure the magnitude and frequency of the ranges of strain experienced by the Nibley Bridge.
Download or read book Developments in International Bridge Engineering written by Alp Caner and published by Springer. This book was released on 2015-08-11 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book includes peer-reviewed contributions selected from presentations given at the Istanbul Bridge Conference 2014, held from August 11 – 13 in Istanbul, Turkey. It reports on the current challenges in bridge engineering faced by professionals around the globe, giving a special emphasis to recently developed techniques, innovations and opportunities. The book covers key topics in the field, including modeling and analysis methods; construction and erection techniques; design for extreme events and condition assessment and structural health monitoring. There is a balanced presentation of theory, research and practice. This book, which provides the readers with a comprehensive and timely reference guide on current practices in bridge engineering, is intended for professionals, academic researchers and students alike.
Download or read book Impact of Extreme Summer Temperatures on Bridge Structures written by Ryan Michael Hagedorn and published by . This book was released on 2016 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change and its effect on weather in the United States is a well-documented phenomenon. In particular, extreme heat waves have become more intense, more frequent, and longer lasting, especially in the southern United States. As with much of America's transportation infrastructure, prestressed concrete bridge girders experience the effects of these heat waves. Uneven heating of optimized bridge girder sections results in large non-linear temperature gradients. In this study, temperature was monitored in three different AASHTO I-girders to determine the vertical and transverse temperature gradients in a pre-deck placement condition. It was determined that the current design standard, which uses a non-linear vertical thermal gradient, was inaccurate in both shape and magnitude for girders Type IV and smaller in this condition. Transverse gradients were also recommended as none are included in design standards. Using three dimensional modeling, this study also sought to understand the response of the girders to non-linear temperature gradients and if they should be accounted for in girder design.
Download or read book Measured Temperatures in Concrete Highway Bridges written by John Holm Wood and published by . This book was released on 1984 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Concrete Box girder Bridges written by Jörg Schlaich and published by IABSE. This book was released on 1982 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Analytical Investigations of the Thermal Behavior of Prestressed Concrete Bridge Girders Including Imperfections written by Jonghang Lee and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental and analytical study was conducted on a BT-63 prestressed concrete girder to investigate the thermal effects on the girder. A 2D finite element heat transfer analysis model was then developed which accounted for heat conduction, convection, radiation, and irradiation. The solar radiation was predicted using the location and geometry of the girder, variations in the solar position, and the shadow from the top flange on other girder surfaces. The girder temperatures obtained from the 2D heat transfer analysis matched well with the measurements. Using the temperatures from the 2D heat transfer analysis, a 3D solid finite element analysis was performed assuming the temperatures constant along the length of the girder. The maximum vertical displacement due to measured environmental conditions was found to be 0.29 inches and the maximum lateral displacement was found to be 0.57 inches. Using the proposed numerical approach, extremes in thermal effects including seasonal variations and bridge orientations were investigated around the United States to propose vertical and transverse thermal gradients which could then be used in the design of I-shaped prestressed concrete bridge girders. A simple beam model was developed to calculate the vertical and lateral thermal deformations which were shown to be within 6% of the 3D finite element analyses results. Finally, equations were developed to predict the maximum thermal vertical and lateral displacements for four AASHTO-PCI standard girders. To analyze the combined effects of thermal response, initial sweep, and bearing support slope on a 100-foot long BT-63 prestressed concrete girder, a 3D finite element sequential analysis procedure was developed which accounted for the changes in the geometry and stress state of the girder in each construction stage. The final construction stage then exposed the girder to thermal effects and performed a geometric nonlinear analysis which also considered the nonlinear behavior of the elastomeric bearing pads. This solution detected an instability under the following conditions: support slope of 5¡©6 and initial sweep of 4.5 inches.
Download or read book Segmental Concrete Box Girder Bridge Thermal Analysis written by Arzu Ipek Yilmaz and published by . This book was released on 2019-02-03 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NCHRP Report 519 written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
