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A Field Study Of Diaphragm Behavior And Performance In Multigirder Steel Bridges
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Book Synopsis A Field Study of Diaphragm Behavior and Performance in Multigirder Steel Bridges by : Thomas Eric Stafford
Download or read book A Field Study of Diaphragm Behavior and Performance in Multigirder Steel Bridges written by Thomas Eric Stafford and published by . This book was released on 1996 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transportation Research Record written by and published by . This book was released on 1999 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Seismic Retrofit of Slab-on-girder Steel Bridges Using Ductile End-diaphragms by : Seyed Mehdi Zahrai
Download or read book Seismic Retrofit of Slab-on-girder Steel Bridges Using Ductile End-diaphragms written by Seyed Mehdi Zahrai and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many steel bridges have suffered severe diaphragm (cross-frame) damage during recent earthquakes around the world. The relative role played by intermediate and end-diaphragms in providing lateral load resistance, and the consequences of diaphragm damage on bridge seismic response have not been studied. These bridges are also frequently supported by seismically vulnerable non-ductile substructures whose seismic retrofit can be, in many cases, a rather costly operation. This research addresses three related issues to the seismic behavior of slab-on-girder steel highway bridges: (i) the impact of diaphragm on their seismic performance, (ii) innovative methods for their seismic retrofit and (iii) corrosion effects on the strength and ductility of their steel members. To study the first issue, research is conducted to quantitatively investigate the impact of diaphragms on the seismic response of these steel bridges. It is shown that a small end-diaphragm stiffness is sufficient to make the entire superstructure behave as a unit in the elastic range. However, a dramatic shift in seismic behavior occurs once those end-diaphragms fail, with a sizeable period elongation, considerably larger lateral displacements and higher propensity to damage due to P-$\Lambda$ effects. For seismic retrofits of these bridges, this research consists of four essential parts: development of the ductile end-diaphragm concept, development of a design procedure, a series of inelastic analyses to validate the concept, and testing of all scale models for the proposed end-diaphragms to further verify the concept and to validate the proposed detailing. First, to take advantage of the benefits granted by the presence of a steel superstructure, an innovative, economical effective and simple to implement seismic retrofit strategy, using ductile steel bridge end-diaphragms (such as shear panels, eccentrically braced frames and triangular-plate added damping and stiffness devices) has been developed. Second, a step by step design procedure for ductile end-diaphragms is proposed and potential limits of application are indicated. In the third part, the DRAIN-2DX and ADINA programs are used to conduct nonlinear inelastic analyses of these retrofitted bridges and investigate their expected seismic behavior. Test results demonstrate the effectiveness of the proposed ductile end-diaphragms as effective passive energy dissipation systems in slab-on-girder steel bridges. For the third issue, the effect of corrosion on the strength and ductility of steel members is also studied to investigate the long-term performance of the ductile end-diaphragms proposed here. To generate preliminary data, a few rusted pieces taken from an existing steel bridge have been subjected to numerous cycles of alternating plasticity in flexure. Specimens had up to a 60% loss of cross-sectional area due to corrosion. This limited test program revealed that, while stable hysteretic behavior comparable to that of unrusted specimen is possible, premature failure under alternating plasticity can typically develop (in spite of satisfactory ductile behavior under monotonic loading). Irregularities along the severely rusted surface apparently act as crack initiators and precipitate crack propagation throughout the section. (Abstract shortened by UMI.).
Book Synopsis Rapid Assessment of Distortional Stresses in Multi-girder Steel Bridges by : Benjamin Severtson
Download or read book Rapid Assessment of Distortional Stresses in Multi-girder Steel Bridges written by Benjamin Severtson and published by . This book was released on 2004 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multi-girder steel bridges are found as part of the transportation infrastructure of countries throughout the world. These bridges are typically constructed with a steel reinforced concrete deck rigidly attached to the top flange of steel girders. The deck and the transverse steel members distribute loads laterally between bridge girders. The weld connecting transverse stiffeners to the girder web are commonly terminated several inches away from the girder flanges to avoid overlapping with the web-to-flange connection weld, leaving a short, unstiffened portion of the girder web-the web gap. The large flexibility of the web gap region relative to the other components forces it to accommodate the majority of the distortion. Since 1998, several research efforts have investigated methods for predicting the amount of web gap stress a bridge will experience during its service life. Phase I of this research resulted in a simple equation for estimating web gap stress using data collected during field testing and subsequent finite modeling of a skew supported bridge with staggering bent-plate diaphragms. Phase II produced an approximate method for predicting diaphragm differential deflection of skew supported bridges with bent-plate diaphragms. The combined result of Phase I and Phase II was a useful method for predicting peak web gap stress in skewed multi-girder steel bridges with staggered bent-plate diaphragms. The next step was to develop a reliable procedure for the rapid assessment of distortional stresses in steel bridges that includes a test of the applicability of this procedure to bridges with geometries differing from those that formed the basis of the previous research. As a consequence of this most current research, the authors propose changes and recommend modifications of previously developed methods of field measurement and assessment.
Book Synopsis Feasibility of Diaphragm Removal from Multigirder Steel Bridges by : Daniel Glenn Davis
Download or read book Feasibility of Diaphragm Removal from Multigirder Steel Bridges written by Daniel Glenn Davis and published by . This book was released on 1995 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Analysis of Girder Differential Deflection and Web Gap Stress for Rapid Assessment of Distortional Fatigue in Multi-girder Steel Bridges by : Huijuan Li
Download or read book Analysis of Girder Differential Deflection and Web Gap Stress for Rapid Assessment of Distortional Fatigue in Multi-girder Steel Bridges written by Huijuan Li and published by . This book was released on 2005 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Distortion-induced fatigue cracking in unstiffened web gaps is common in steel bridges. Previous research by the Minnesota Department of Transportation (Mn/DOT) developed methods to predict the peak web gap stress and maximum differential deflection based upon field data and finite element analyses from two skew supported steel bridges with staggered bent-plate and cross-brace diaphragms, respectively. This project aimed to test the applicability of the proposed methods to a varied spectrum of bridges in the Mn/DOT inventory. An entire bridge model (macro-model) and a model encompassing a portion of the bridge surrounding the diaphragm (micro-model) were calibrated for two instrumented bridges. Dual-level analyses using the macroand micro-models were performed to account for the uncertainties of boundary conditions. Parameter studies were conducted on the prototypical variations of the bridge models to define the sensitivity of diaphragm stress responses to typical diaphragm and bridge details. Based on these studies, the coefficient in the web gap stress formula was calibrated and a linear prediction of the coefficient was proposed for bridges with different span lengths. Additionally, the prediction of differential deflection was calibrated to include the influence of crossbrace diaphragms, truck loading configurations and additional sidewalk railings. A simple approximation was also proposed for the influence of web gap lateral deflection on web gap stress. This research studied the effect of two enzymes as soil stabilizers on two soil types to determine how and under what conditions they function. Researchers evaluated the chemical composition, mode of action, resilient modulus, and shear strength to determine the effects of the enzymes A and B on the soils I and II. The enzymes produced a high concentration of protein and observations suggest the enzymes behave like a surfactant, which effects its stabilization performance. The specimens were subjected to testing of varying lengths of time to determine their performance. Researchers observed an increase in the resilient modulus as the curing time increased but that an increase in application rate, as suggested by manufacturers, did not improve the performance of the enzymes. The study also suggests noticeable differences between the two enzymes and their effects on the soils in terms of resilient modulus and the stiffness of the soil.
Book Synopsis Concrete in Pavements and Structures by : National Research Council (U.S.). Transportation Research Board
Download or read book Concrete in Pavements and Structures written by National Research Council (U.S.). Transportation Research Board and published by . This book was released on 1999 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Cross-frame and Diaphragm Behavior for Steel Bridges with Skewed Supports by : Todd Helwig
Download or read book Cross-frame and Diaphragm Behavior for Steel Bridges with Skewed Supports written by Todd Helwig and published by . This book was released on 2005 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Cross-frame and Diaphragm Behavior for Steel Bridges with Skewed Supports by : Liqun Wang
Download or read book Cross-frame and Diaphragm Behavior for Steel Bridges with Skewed Supports written by Liqun Wang and published by . This book was released on 2002 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Distortion-induced Fatigue in Multi-girder Steel Bridges by : Dmitri Jajich
Download or read book Distortion-induced Fatigue in Multi-girder Steel Bridges written by Dmitri Jajich and published by . This book was released on 2000 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the findings of a project with the following goals: to implement a field instrumentation and monitoring program for a typical multi-girder steel bridge on skew supports that may be susceptible to web-gap distortion; to assess the frequency and magnitude of the distortional fatigue stresses at the web-stiffener connections; and to evaluate the impact of these stresses on fatigue life. Measurements from 12 independent strain gauges were continuously monitored and recorded for more than three months on Minnesota Department of Transportation (Mn/DOT) bridge #27734. Truck loading tests also were conducted. Predicted web-gap fatigue life based on the long-term monitoring data from Mn/DOT bridge #27734 ranges from 45 to 75 years. Comparison of web-gap stresses with primary design stresses reveals that web-gap distortional stresses are comparatively high. The report also highlights a detailed finite element study to better understand the web-gap stress mechanism and to compare experimental results with theoretical predictions. Study results have important implications for investigators of distortion-induced web-gap fatigue. They indicate that the actual stress at the so-called hotspot may be as much as twice the stress measured at the strain gauge. The report includes a method for estimating girder deflections and web-gap stress.
Book Synopsis Distortion-induced Fatigue Cracking in Steel Bridges by : John W. Fisher
Download or read book Distortion-induced Fatigue Cracking in Steel Bridges written by John W. Fisher and published by Transportation Research Board. This book was released on 1990 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Steel Box Girder Bridges written by and published by Thomas Telford Publishing. This book was released on 1973 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Analysis Tools and Rapid Screening Data for Assessing Distortional Fatigue in Steel Bridge Girders by : Evan Berglund
Download or read book Analysis Tools and Rapid Screening Data for Assessing Distortional Fatigue in Steel Bridge Girders written by Evan Berglund and published by . This book was released on 2001 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Engineering for Structural Stability in Bridge Construction by : Federal Highway Federal Highway Administration
Download or read book Engineering for Structural Stability in Bridge Construction written by Federal Highway Federal Highway Administration and published by . This book was released on 2020-07-19 with total page 669 pages. Available in PDF, EPUB and Kindle. Book excerpt: This manual is intended to serve as a reference. It will provide technical information which will enable Manual users to perform the following activities:Describe typical erection practices for girder bridge superstructures and recognize critical construction stagesDiscuss typical practices for evaluating structural stability of girder bridge superstructures during early stages of erection and throughout bridge constructionExplain the basic concepts of stability and why it is important in bridge erection* Explain common techniques for performing advanced stability analysis along with their advantages and limitationsDescribe how differing construction sequences effect superstructure stabilityBe able to select appropriate loads, load combinations, and load factors for use in analyzing superstructure components during constructionBe able to analyze bridge members at various stages of erection* Develop erection plans that are safe and economical, and know what information is required and should be a part of those plansDescribe the differences between local, member and global (system) stability
Download or read book Highway Research Abstracts written by and published by . This book was released on 1992 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Use of Adhesives to Retrofit Out-of-plane Distortion Induced Fatigue Cracks by : Yuying Hu
Download or read book Use of Adhesives to Retrofit Out-of-plane Distortion Induced Fatigue Cracks written by Yuying Hu and published by . This book was released on 2005 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prior to 1985, it was common practice to avoid welding the connection plates to the tension flange of the girders of steel bridges. However, extensive fatigue cracking has developed in the unstiffened web gaps because of out-ofplane distortion. A new retrofit option was investigated that uses a room-temperature-cured two-part epoxy (3M Adhesive DP460-NS) to join a small length of 3/4-inch thick steel angle to the tension flange and the connection plate. A field test on two skewed bridges showed that the adhesive-angle retrofit system decreased the out-of-plane strain range by 40 to 50% when the original strain range was more than 50 microstrains. The ten adhesive-angle retrofits remained in place and were in good condition after three and a half years, suggesting that the chosen adhesive had good environmental durability. A laboratory large-scale specimen test with 8 web gaps showed that the retrofit system stopped or retarded most cracks even without stop holes when the measured out-of-plane strains were approximately 600 microstrains. Coupon tests conducted to investigate the environmental durability of the chosen adhesive showed that the chosen adhesive is suitable for applications at room or low temperature, even with high relative humidity.
Book Synopsis Piezoelectric Energy Harvesting by : Alper Erturk
Download or read book Piezoelectric Energy Harvesting written by Alper Erturk and published by John Wiley & Sons. This book was released on 2011-04-04 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: The transformation of vibrations into electric energy through the use of piezoelectric devices is an exciting and rapidly developing area of research with a widening range of applications constantly materialising. With Piezoelectric Energy Harvesting, world-leading researchers provide a timely and comprehensive coverage of the electromechanical modelling and applications of piezoelectric energy harvesters. They present principal modelling approaches, synthesizing fundamental material related to mechanical, aerospace, civil, electrical and materials engineering disciplines for vibration-based energy harvesting using piezoelectric transduction. Piezoelectric Energy Harvesting provides the first comprehensive treatment of distributed-parameter electromechanical modelling for piezoelectric energy harvesting with extensive case studies including experimental validations, and is the first book to address modelling of various forms of excitation in piezoelectric energy harvesting, ranging from airflow excitation to moving loads, thus ensuring its relevance to engineers in fields as disparate as aerospace engineering and civil engineering. Coverage includes: Analytical and approximate analytical distributed-parameter electromechanical models with illustrative theoretical case studies as well as extensive experimental validations Several problems of piezoelectric energy harvesting ranging from simple harmonic excitation to random vibrations Details of introducing and modelling piezoelectric coupling for various problems Modelling and exploiting nonlinear dynamics for performance enhancement, supported with experimental verifications Applications ranging from moving load excitation of slender bridges to airflow excitation of aeroelastic sections A review of standard nonlinear energy harvesting circuits with modelling aspects.
