928 resultados para Procedures coordination
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In response to the mandate on Load and Resistance Factor Design (LRFD) implementations by the Federal Highway Administration (FHWA) on all new bridge projects initiated after October 1, 2007, the Iowa Highway Research Board (IHRB) sponsored these research projects to develop regional LRFD recommendations. The LRFD development was performed using the Iowa Department of Transportation (DOT) Pile Load Test database (PILOT). To increase the data points for LRFD development, develop LRFD recommendations for dynamic methods, and validate the results of LRFD calibration, 10 full-scale field tests on the most commonly used steel H-piles (e.g., HP 10 x 42) were conducted throughout Iowa. Detailed in situ soil investigations were carried out, push-in pressure cells were installed, and laboratory soil tests were performed. Pile responses during driving, at the end of driving (EOD), and at re-strikes were monitored using the Pile Driving Analyzer (PDA), following with the CAse Pile Wave Analysis Program (CAPWAP) analysis. The hammer blow counts were recorded for Wave Equation Analysis Program (WEAP) and dynamic formulas. Static load tests (SLTs) were performed and the pile capacities were determined based on the Davisson’s criteria. The extensive experimental research studies generated important data for analytical and computational investigations. The SLT measured load-displacements were compared with the simulated results obtained using a model of the TZPILE program and using the modified borehole shear test method. Two analytical pile setup quantification methods, in terms of soil properties, were developed and validated. A new calibration procedure was developed to incorporate pile setup into LRFD.
Resumo:
The Federal Highway Administration (FHWA) mandated utilizing the Load and Resistance Factor Design (LRFD) approach for all new bridges initiated in the United States after October 1, 2007. As a result, there has been a progressive move among state Departments of Transportation (DOTs) toward an increased use of the LRFD in geotechnical design practices. For the above reasons, the Iowa Highway Research Board (IHRB) sponsored three research projects: TR-573, TR-583 and TR-584. The research information is summarized in the project web site (http://srg.cce.iastate.edu/lrfd/). Two reports of total four volumes have been published. Report volume I by Roling et al. (2010) described the development of a user-friendly and electronic database (PILOT). Report volume II by Ng et al. (2011) summarized the 10 full-scale field tests conducted throughout Iowa and data analyses. This report presents the development of regionally calibrated LRFD resistance factors for bridge pile foundations in Iowa based on reliability theory, focusing on the strength limit states and incorporating the construction control aspects and soil setup into the design process. The calibration framework was selected to follow the guidelines provided by the American Association of State Highway and Transportation Officials (AASHTO), taking into consideration the current local practices. The resistance factors were developed for general and in-house static analysis methods used for the design of pile foundations as well as for dynamic analysis methods and dynamic formulas used for construction control. The following notable benefits to the bridge foundation design were attained in this project: 1) comprehensive design tables and charts were developed to facilitate the implementation of the LRFD approach, ensuring uniform reliability and consistency in the design and construction processes of bridge pile foundations; 2) the results showed a substantial gain in the factored capacity compared to the 2008 AASHTO-LRFD recommendations; and 3) contribution to the existing knowledge, thereby advancing the foundation design and construction practices in Iowa and the nation.
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Agreed-upon procedures report on the City of Breda, Iowa for the period December 1, 2013 through November 30, 2014
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Agreed-upon procedures report on the City of Randalia, Iowa for the period February 1, 2014 through January 31, 2015
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Agreed–upon procedures report on the Iowa Turkey Marketing Council for the period January 1, 2013 through December 31, 2014
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Agreed-upon procedures report on the City of Elkhart, Iowa for the period April 1, 2014 through March 31, 2015
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Agreed-upon procedures report on the City of Cumming, Iowa for the period December 1, 2013 through November 30, 2014
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Agreed-upon procedures report on the City of Dawson, Iowa for the period January 1, 2014 through December 31, 2014
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Agreed-upon procedures report on the City of Nichols, Iowa for the period January 1, 2013 through December 31, 2014
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Agreed-upon procedures report on Eden Township in Fayette County, Iowa for the period July 1, 2003 through April 30, 2015
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Agreed-upon procedures report on the City of Blairstown, Iowa for the period December 1, 2013 through November 30, 2014
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Agreed-upon procedures report on the City of Oxford, Iowa for the period July 1, 2013 through June 30, 2014
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Agreed–upon procedures report on the City of Riverside, Iowa for the period July 1, 2013 through June 30, 2014
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Agreed-upon procedures report on the City of Laurel, Iowa for the period February 1, 2014 through January 31, 2015
