Modeling of Mn/ROAD Test Sections with the CRREL Mechanistic Pavement Design Procedure

Modeling of Mn/ROAD Test Sections with the CRREL Mechanistic Pavement Design Procedure PDF

Author: Susan R. Bigl

Publisher: DIANE Publishing

Published: 1996

Total Pages: 50

ISBN-13: 1428913955

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The U.S. Army Cold Regions Research and Engineering Laboratory is developing a mechanistic pavement design procedure for use in seasonal frost areas. The procedure was used to predict pavement performance of some test sections under construction at the Mn/ROAD facility. Simulations were conducted in three phases, investigating the effects on predictions of water table position, subgrade characteristics, asphalt model, and freeze season characteristics. The procedure predicted significantly different performance by the different test sections and highly variable results depending on the performance model applied. The simulated performance of the tests sections also was greatly affected by the subgrade conditions, e.g., density, soil moisture, and water table depth. In general, predictions for the full depth asphalt sections indicate that they will not fail due to cracking, but two of the three criteria for subgrade rufting indicate failure before the five or 10 year design life of the sections. Conventional sections are predicted not to fail due to subgrade rutting; however, sections including the more frost susceptible bases in their design are predicted to fail due to asphalt cracking relatively early in their design life, and sections with nonfrost susceptible bases are predicted to fail towards the end of the design life.

Monthly Catalog of United States Government Publications

Monthly Catalog of United States Government Publications PDF

Author: United States. Superintendent of Documents

Publisher:

Published: 1977

Total Pages: 992

ISBN-13:

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February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index

Technical Assessment of Maglev System Concepts

Technical Assessment of Maglev System Concepts PDF

Author:

Publisher:

Published: 1998

Total Pages: 242

ISBN-13:

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The Government Maglev System Assessment Team operated from 1991 to 1993 as part of the National Maglev Initiative. They assessed the technical viability of four U.S. Maglev system concepts, using the French TGV high speed train and the German TR07 Maglev system as assessment baselines. Maglev in general offers advantages that include high speed potential, excellent system control, high capacity, low energy consumption, low maintenance, modest land requirements, low operating costs, and ability to meet a variety of transportation missions. Further, the U.S. Maglev concepts could provide superior performance to TR07 for similar cost or similar performance for less cost. They also could achieve both lower trip times and lower energy consumption along typical U.S. routes. These advantages result generally from the use of large gap magnetic suspensions, more powerful linear synchronous motors and tilting vehicles. Innovative concepts for motors, guideways, suspension, and superconducting magnets all contribute to a potential for superior long term performance of U.S. Maglev systems compared with TGV and TR07.