Author: Albert F. DiMillio
Publisher:
ISBN:
Category :
Languages : en
Pages : 48

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Author: Albert F. DiMillio
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 48

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Book Description
Abstract A visual inspection was made of the structural condition of 148 highway bridges supported by spread footings on compacted fill throughout the State of Washington. The approach pavements and other bridge appurtenances were also inspected for damage or distress that could be attributed to the use of spread footings on compacted fill. This review, in conjunction with detailed investigations of the foundation movement of 28 selected bridges, was used to evaluate the performance of spread footings on compacted fills. It was concluded that spread footings can provide a satisfactory alternative to piles especially when high embankments of good quality borrow materials are constructed over satisfactory foundation soils . None of the bridges investigated displayed any safety problems serious functional distress. All bridges were in good condition and many were found to be in very good condition. In addition to the performance evaluation, cost-effectiveness analyses and tolerable movement correlation studies were made to further substantiate the feasibility of using spread footings in lieu of expensive deep foundation systems. Cost analyses showed spread footings were 50-65 percent cheaper than the a1 ternate choice o f pile foundations. Foundation movement studies showed t h a t these bridges have easily tolerated differential settlements of 1-3 inches (25-75 mm) without serious distress.

Author:
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 242

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"A long-term study of the settlement performance of 21 bridge foundations supported on cohesionless soil-sand or silt- was completed to provide a reliable data base for engineering evaluation"--Abstract

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 704

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Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 838

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Author: Naresh C. Samtani
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 84

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Book Description
The FHWA believes that spread footings on soils are underutilized because designers encounter one or more of the following obstacles: (a) limited knowledge of AASHTO/FHWA technical references that pertain to spread footings on soils to support bridges; (b) limited knowledge of adequate performance data for spread footings; (c) unrealistic tolerable settlement criteria; (d) overestimation of loads used to calculate settlement; and (e) the use of conservative settlement prediction methods. These obstacles have resulted in institutional biases and overly conservative and excessively costly institutional processes that lead to the unnecessary use of costlier deep foundation systems. The primary goal of this report is to promote the use of spread footings bearing on competent natural soils, improved soils, and engineered fill materials as a routine alternative to deep foundations for support of bridges by addressing the factors identified above. Documented performance data is used to make this case. The report also presents powerful concepts such as construction-point analysis and angular distortions to demonstrate the efficacy of using spread footings. Implementation of these concepts requires only that conventional computations be taken one step further without any requirement for advanced computational skills. The report presents sources of information that agencies and designers can use as references in their project applications. The report contains comprehensive appendices that treat in detail many of the topics discussed in the report. For example, one such appendix provides an introduction to Load and Resistance Factor Design (LRFD) that permits a rational approach to the consideration of spread footings on soils as a feasible alternative to deep foundations.

Author: Harvey E. Wahls
Publisher: Transportation Research Board
ISBN: 9780309049054
Category : Technology & Engineering
Languages : en
Pages : 56

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Book Description
Includes case histories of the Dumbarton Bridge (San Francisco Bay, Calif.), the Rainier Avenue Embankment (Seattle, Wash.) and the Gallows Road Grade Separation (Fairfax, Va.)

Author: Chong Tang
Publisher: CRC Press
ISBN: 0429655959
Category : Technology & Engineering
Languages : en
Pages : 497

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Book Description
Model Uncertainties in Foundation Design is unique in the compilation of the largest and the most diverse load test databases to date, covering many foundation types (shallow foundations, spudcans, driven piles, drilled shafts, rock sockets and helical piles) and a wide range of ground conditions (soil to soft rock). All databases with names prefixed by NUS are available upon request. This book presents a comprehensive evaluation of the model factor mean (bias) and coefficient of variation (COV) for ultimate and serviceability limit state based on these databases. These statistics can be used directly for AASHTO LRFD calibration. Besides load test databases, performance databases for other geo-structures and their model factor statistics are provided. Based on this extensive literature survey, a practical three-tier scheme for classifying the model uncertainty of geo-structures according to the model factor mean and COV is proposed. This empirically grounded scheme can underpin the calibration of resistance factors as a function of the degree of understanding – a concept already adopted in the Canadian Highway Bridge Design Code and being considered for the new draft for Eurocode 7 Part 1 (EN 1997-1:202x). The helical pile research in Chapter 7 was recognised by the 2020 ASCE Norman Medal.

Author: J.-L. Briaud
Publisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 272

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Book Description
Contains the results of a full scale load testing program used to predict and measure the behaviour of five spread footings on sand. This title presents the data upon which all predictions are based; describes methodologies and judgments used to make the predictions; and also summarizes the predictions and compares predicted responses.

Author:
Publisher:
ISBN:
Category : Highway engineering
Languages : en
Pages : 688

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