GLORIA

GEOMAR Library Ocean Research Information Access

X

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Mobility and traffic research  (4)
  • 1
    Online Resource
    Online Resource
    Soil Suction and Behavior of Chemically Treated Clays
    SAGE Publications ; 2007
    In:  Transportation Research Record: Journal of the Transportation Research Board Vol. 2026, No. 1 ( 2007-01), p. 30-38
    Details
    In: Transportation Research Record: Journal of the Transportation Research Board, SAGE Publications, Vol. 2026, No. 1 ( 2007-01), p. 30-38
    Abstract: Expansive clay soils have caused significant damage throughout the world. Chemical stabilizing agents have been used to reduce the swell of expansive clay soils, but the effect of chemical treatment on the matric and osmotic suction of soils has not been investigated previously. Two subject soils were chosen to study soil suction and the behavior of chemically treated clay. One soil, with high swell potential, was from Irving, Texas. The other soil, with moderate swell potential, was from Slater, Missouri. Hydrated lime and KIS (a proprietary solution containing potash and ammonium lignosulfonate) were used as chemical stabilizers. Select physical and chemical properties of these soils before and after reacting with chemical stabilizers were determined. Total suction, matric suction, and osmotic suction were determined with the use of a dewpoint potentiometer (WP4) and an electrical conductivity probe. Matric suction arises from capillary forces, soil texture, and adsorption forces of clay. Osmotic suction results from the balance of salt concentrations in soil water. When the soils reacted with chemical stabilizers, the osmotic suction increased because of the ion concentrations in the soil. Practical methods were used to determine the osmotic and matric suction of natural soils and of chemically treated soils. Soil suction was correlated with other clay soil properties. Practical methods to separate soil suction parameters were used, and the validity of soil suction to predict chemically treated clay behavior was found to be problematic.
    Type of Medium: Online Resource
    ISSN: 0361-1981 , 2169-4052
    URL: Article
    DOI: 10.3141/2026-04
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2007
    detail.hit.zdb_id: 2403378-9
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 2
    Online Resource
    Online Resource
    Computation of Skims for Large-Scale Implementations of Integrated Activity-Based and Dynamic Traffic Assignment Models
    SAGE Publications ; 2016
    In:  Transportation Research Record: Journal of the Transportation Research Board Vol. 2563, No. 1 ( 2016-01), p. 134-143
    Details
    In: Transportation Research Record: Journal of the Transportation Research Board, SAGE Publications, Vol. 2563, No. 1 ( 2016-01), p. 134-143
    Abstract: Integrated activity-based model (ABM) and dynamic traffic assignment (DTA) frameworks have emerged as promising tools to support transportation planning and operations, particularly in the context of novel technologies and data sources. This research proposes an approach to characterize the implementation of integrated ABM-DTA models and seeks to facilitate the interpretation and comparison of frameworks and, ultimately, the selection of appropriate tools. The importance of the dimensions considered in this characterization is illustrated through a detailed analysis of the computation of skims. Skims are the level of service (LOS) metric produced by DTA models, and the computation of skims may impact the performance and convergence of ABM-DTA applications. Numerical results from experiments on a regional ABM-DTA model in Austin, Texas, suggest that skims produced at relatively small time steps (10 to 30 min) may lead to a faster integrated model convergence. Finer time-grained skims are also observed to capture sharper temporal peaking patterns in the LOS. This work considers two skim computation methods; the analysis of the results suggests that simpler techniques are adequate, as the inherent variability of travel times from simulation overshadows any gain in precision from more complex methods. This study also uses promising techniques to visualize and analyze the model results, a challenging task in the context of highly disaggregate models and the subject of further research. The insights from this research effort can inform future research on the implementation of ABM-DTA methods and practical applications of existing frameworks.
    Type of Medium: Online Resource
    ISSN: 0361-1981 , 2169-4052
    URL: Article
    DOI: 10.3141/2563-18
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2016
    detail.hit.zdb_id: 2403378-9
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 3
    Online Resource
    Online Resource
    Finding and Exploring Use of Commodity-Specific Data Sources for Commodity Flow Modeling
    SAGE Publications ; 2017
    In:  Transportation Research Record: Journal of the Transportation Research Board Vol. 2646, No. 1 ( 2017-01), p. 77-83
    Details
    In: Transportation Research Record: Journal of the Transportation Research Board, SAGE Publications, Vol. 2646, No. 1 ( 2017-01), p. 77-83
    Abstract: Commodity flow modeling studies rely on traditional data sources, such as the Commodity Flow Survey, the Freight Analysis Framework, Transearch, surveys, the U.S. census, county business patterns, and input–output models. The strengths and shortcomings of those data sources have been evaluated in the literature; the sources can be useful for modeling, but they do not necessarily support a supply chain approach or provide the level of detail or accuracy desired for modeling a particular commodity’s supply chain and flow on a city or state roadway network. This paper expands on the work of NCFRP Report 35: Implementing the Freight Transportation Data Architecture: Data Element Dictionary by finding existing data sources unique to specific commodities that identify key supply chain locations and industry relationships and that provide more detail about commodity quantity and movement to overcome the limitations of traditional freight data sources. The goal of the investigation was to find more data sets to use in commodity flow modeling. For each commodity, this paper describes data sources found, data attributes, and how those data were used to estimate flow from origins and destinations within supply chain links. The commodity-specific approach opens doors to sources of data not normally incorporated into transportation research.
    Type of Medium: Online Resource
    ISSN: 0361-1981 , 2169-4052
    URL: Article
    DOI: 10.3141/2646-09
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2017
    detail.hit.zdb_id: 2403378-9
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 4
    Online Resource
    Online Resource
    Analysis of Current State Rigid Pavement Design Practices in the United States
    SAGE Publications ; 1996
    In:  Transportation Research Record: Journal of the Transportation Research Board Vol. 1525, No. 1 ( 1996-01), p. 72-82
    Details
    In: Transportation Research Record: Journal of the Transportation Research Board, SAGE Publications, Vol. 1525, No. 1 ( 1996-01), p. 72-82
    Abstract: Current portland cement concrete pavement design practices and the key concrete pavement design features used by state highway agencies in the United States are summarized. This information was obtained from a comprehensive survey conducted in 1994 and 1995 under an NCHRP project. Pavement types, design methodologies, and reliability levels are included, along with many design inputs. Parameters that the states use to characterize pavement site conditions, including climate, subgrade, and traffic conditions, are given. The designed concrete slab thicknesses for different site condition combinations are compared. An analysis of variance was conducted to compare the mean slab thicknesses designed in different climatic regions. This examination and summary of the details of current pavement design practices and design features for concrete pavements in the United States will be of interest to both pavement researchers and practitioners.
    Type of Medium: Online Resource
    ISSN: 0361-1981 , 2169-4052
    URL: Article
    DOI: 10.1177/0361198196152500108
    Language: English
    Publisher: SAGE Publications
    Publication Date: 1996
    detail.hit.zdb_id: 2403378-9
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...