Browsing by Author "Sterling, Raymond L."

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    Indirect Costs of Utility Placement and Repair Beneath Streets
    (Minnesota Department of Transportation, 1994-08) Sterling, Raymond L.
    The report examines policy issues related to the placement of utilities beneath public rights-of-way. The principal issues discussed are: recognition of the present and future value of the space beneath public rights-of-way in space allocation decisions, methodologies for assessing the full societal costs of utility work in congested roadways, implementation of contractual practices and fee structures to mitigate conditions involving high societal costs, and the work that would be necessary to attempt to include the impact of utility cuts on life-cycle pavement costs.
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    Low-Vibration Methods of Soil Compaction for Urban Utility Projects: Phase 2
    (1995-04) Sterling, Raymond L.
    This report presents the findings of the second phase of an exploratory project to assess the potential of nonvibratory methods of compaction for utility-related compaction needs. Proposed refinements and additions to existing compaction procedures are based on the use of an alternating flooding and vacuum procedure introduced through a pipe or series of pipes embedded in the soil. This process had been demonstrated in early Phase I laboratory tests to give better results than flooding alone for granular soils. Phase II laboratory and field tests produced compaction results ranging from an acceptable level of compaction to an unacceptable level. The flood/vacuum method appeared to work best in well-graded granular materials including some, but not an excessive amount of, fine particles. The cycle times for flooding and vacuum removal of the water appeared to be too long for practical use. The flood/vacuum technique by itself, or without reasonable levels of static compaction, does not appear to be a viable technique for field use. It appears that results from the technique could be significantly approved by adding mechanical disturbance of the backfill material or vibration energy to the flooding cycle.
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    Rapid Determination of Field Properties of Compacted Materials
    (Center for Transportation Studies, University of Minnesota, 1997-12) Sterling, Raymond L.
    The report describes the results of a limited investigation into the technical progress and acceptance of techniques for field determination of the engineering properties of compacted materials. Although some of these techniques have been investigated for several decades, few are in common use. The reports discusses the benefits and limitations of the principal techniques and concentrates on acceptance issues for their use in practice.
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    Underground Station Design Issues for Light Rail Transit in the Twin Cities Geology
    (1992-01) Carmody, John; Sterling, Raymond L.
    This study is intended to identify and analyze selected design issues for underground transit stations in the Twin Cities geology. The first part of the study consists of six chapters in which key underground station design issues are discussed. The second part includes the development and analysis of conceptual designs for three potential underground station sites: downtown Minneapolis, the University of Minnesota, and the airport. These designs reveal a number of issues related to specific sites and are intended to establish a range of options to be further evaluated by system planners. The report does not attempt to reproduce all station design provisions in the various applicable codes of practice, but does present many design suggestions culled from the authors' experience with underground building design and from the literature on transit station design and safety. A brief summary of highlights and conclusions, where applicable, follows for each chapter.