Evaluation of Non-Composite Steel Girder Bridges Using Field Load Testing and a Calibrated Finite-Element Model PDF Download

Author: Mahmood Jaleel Albraheemi
Publisher:
ISBN:
Category : Iron and steel bridges
Languages : en
Pages : 560

View

Book Description

Author: Francisco Garcia
Publisher:
ISBN:
Category : Iron and steel bridges
Languages : en
Pages : 238

View

Book Description
This research aimed to develop a supplemental ANN-based tool to support the Nebraska Department of Transportation (NDOT) in optimizing bridge management investments when choosing between refined modeling, field testing, retrofitting, or bridge replacement. ANNs require an initial investment to collect data and train a network, but offer future benefits of speed and accessibility to engineers utilizing the trained ANN in the future. As the population of rural bridges in the Midwest approaching the end of their design service lives increases, Departments of Transportation are under mounting pressure to balance safety of the traveling public with fiscal constraints. While it is welldocumented that standard code-based evaluation methods tend to conservatively overestimate live load distributions, alternate methods of capturing more accurate live load distributions, such as finite element modeling and diagnostic field testing, are not fiscally justified for broad implementation across bridge inventories. Meanwhile, ANNs trained using comprehensive, representative data are broadly applicable across the bridge population represented by the training data. The ANN tool developed in this research will allow NDOT engineers to predict critical girder distribution factors (GDFs), removing unnecessary conservativism from approximate AASHTO GDFs, potentially justifying load posting removal for existing bridges, and enabling more optimized design for new construction, using ten readily available parameters, such as bridge span, girder spacing, and deck thickness. A key drawback obstructing implementation of ANNs in bridge rating and design is the potential for unconservative ANN predictions. This research provides a framework to account for increased live load effect uncertainty incurred from neural network prediction errors by performing a reliability calibration philosophically consistent with AASHTO Load and Resistance Factor Rating. The study included detailed FEA for 174 simple span, steel girder bridges with concrete decks. Subsets of 163 and 161 bridges within these available cases comprised the ANN design and training datasets for critical moment and shear live load effects, respectively. The reliability calibration found that the ANN live load effect prediction error with mean absolute independent testing error of 3.65% could be safely accommodated by increasing the live load factor by less than 0.05. The study also demonstrates application of the neural network model validated with a diagnostic field test, including discussion of potential adjustments to account for noncomposite bridge capacity and Load Factor Rating instead of Load and Resistance Factor Rating.

Author:
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 294

View

Book Description
Nondestructive dynamic field testing and structural identification studies on three (2, 20, and 43-year-old) steel-stringer bridges are presented. The bridges were rated by code procedures and by field-calibrated comprehensive 3-D finite-element models developed by structural identification. Experimentally measured and analytically simulated modal flexibilities were correlated with bridge deflections obtained under proof-load level truck-load tests.

Author: Fikret Necati Catbas
Publisher: Frontiers Media SA
ISBN: 2889662128
Category : Technology & Engineering
Languages : en
Pages : 212

View

Book Description
This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.

Author: Arthur J. Helmicki
Publisher:
ISBN:
Category : Iron and steel bridges
Languages : en
Pages : 252

View

Book Description
According to the National Bridge Inventory, the most common type of short-to-medium span highway bridge in the US is the reinforced concrete (RC) slab-on-steel girder bridge with RC abutments and piers, comprising approximately half of Ohio's inventory. For these bridges AASHTO currently offers a number of rating methods each of which is based solely on theoretical and design calculations. These methods are known to result in subjective/conservative ratings, not calibrated against field measurements, and hence possibly not objectively reflecting the realities and impacts of individual bridge condition as well as design details. Visual inspections provide at best qualitative and subjective information on bridge condition which is hard to incorporate into the rating process. One result of this approach is the potentially inefficient management and maintenance practices based on conservative/subjective ratings and inspection reports. In addition, there is the need to understand the true impact design and construction practices have on serviceability and safety of the bridge inventory, something which cannot be explored based on the current approaches.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
Many of today's bridge construction projects are erected in stages to limit traffic interruptions or to minimize environmental impacts. Typically, one half of the bridge superstructure is constructed in the first stage and the other half constructed in the second stage. The final stage is to cast a closure strip to join the deck slabs of the two structures together. Due to the inability of current analysis methods to accurately predict the non-composite dead load deflection for steel plate girder bridge during construction, three-dimensional finite element bridge models have been developed to more accurately predict the bridge behavior. However, the bridge engineer must first consider the complexity of and the time spent modeling bridges in this way. The objective of this research is to develop a simplified modeling method to predict the non-composite dead load deflections of the steel plate bridge girder. The study is focused on creating a modeling method for both single span and two-span continuous bridges. Parameters such as bridge skew, cross-frame stiffness, and stay-in-place metal deck forms were considered in the development of the simplified models. By measuring the deflections in the field during the construction, the true non-composite deflection behavior of the bridge was captured and compared to the results from modeling. As a result, the predicted deflection of the simplified models agreed well with the measured results for the single span bridges. Additionally, predicted deflections from the simplified models correlated well with the deflection results from finite element models for the single span bridges. However, the predicted deflections from the simplified models had a poor agreement with the measured results for the two-span continuous bridge. It was also concluded from both field measurements and modeling results that stay-in-place metal deck forms have a significant effect to the non-composite dead load deflection behavior for skewed steel plat.

Author: J. M. Kulicki
Publisher: Transportation Research Board
ISBN: 0309098556
Category : Bridges
Languages : en
Pages : 81

View

Book Description
This report contains the findings of research performed to develop design specifications for horizontally curved steel girder bridges.

Author: Jeremy R. Scott
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 388

View

Book Description
With the use of new materials in bridges, an evaluation of the structural performance of a demonstration bridge containing the new materials is often necessary. This research discusses the validation of the design and construction of a two span continuous HPS 100W bridge in Iredell County North Carolina. This bridge is the first in North Carolina to make use of the new HPS 100W steel, in this case the flanges of the negative moment region over the intermediate pier. The design and construction validation was carried out through 1) a documentation of the weldments to determine if proper fabrication techniques and welding consumables were used, 2) static load testing of the structure, and 3) development of a linear elastic finite element model. During the load testing, static live load deflections were measured using a new laser based technique along with traditional displacement transducers. The static load test results were used to verify the finite element model. A series of analyses were conducted using the finite element model including a non-composite dead load analysis, a truck load analysis based on the load testing, and a modal analysis. The results of these analyses were compared to the load testing results in order to validate the FE model and to the NCDOT design calculations.

Author: David Villegas Jãuregui
Publisher:
ISBN:
Category : Girders
Languages : en
Pages : 742

View

Book Description

Author: Shamim Pakzad
Publisher: Springer
ISBN: 3319297511
Category : Technology & Engineering
Languages : en
Pages : 332

View

Book Description
Dynamics of Civil Structures, Volume 2. Proceedings of the 34th IMAC, A Conference and Exposition on Dynamics of Multiphysical Systems: From Active Materials to Vibroacoustics, 2016, the second volume of ten from the Conference brings together contributions to this important area of research and engineering. Th e collection presents early fi ndings and case studies on fundamental and applied aspects of Structural Dynamics, including papers on: • Modal Parameter Identifi cation • Dynamic Testing of Civil Structures • Human Induced Vibrations of Civil Structures • Model Updating • Operational Modal Analysis • Damage Detection • Bridge Dynamics • Experimental Techniques for Civil Structures • Hybrid testing • Vibration Control of Civil Structures