Location

Arlington, Virginia

Session Start Date

8-11-2008

Session End Date

8-16-2008

Abstract

Residual soils in the Eastern Piedmont Physiographic province are difficult to characterize because of the unique mineralogy and development of the soils. They are derived in place by weathering of the underlying gneiss and schist bedrock, and are characterized by a gradual transition from soil to decomposed-rock to rock with no clear demarcation between the strata. The soils generally consist of low plasticity micaceous clayey silts, sandy silts and silty sands. It is often difficult to obtain undisturbed samples of these soils and Intermediate Geo-Materials, so most shear strength and compressibility properties are derived from experience or correlations with index parameters such as the SPT N-value and Atterberg limits. For the State of Maryland’s Intercounty Connector (ICC) Project, the General Engineering Consultant (GEC), Intercounty Connector Corridor Partners (ICCCP) Joint Venture working directly for the Maryland State Highway Administration (MSHA), performed a Preliminary Geotechnical Subsurface Exploration (PGSE) during the procurement phase so that the Design-Build (DB) teams would develop preliminary designs on which to base their technical and price proposals. As part of the PGSE performed by the GEC for Contract A of the ICC, several undisturbed samples were obtained so that the shear strength parameters could be determined on relatively undisturbed samples. An attempt was made to correlate the SPT N-values and laboratory testing with seismic refraction geophysical exploration to estimate engineering parameters for design of cut slopes, shrink/swell, a cut/cover tunnel, and several bridges for the three general strata. Not only were undisturbed samples tested to determine the shear strength parameters, remolded samples, compacted to 95% of the modified Proctor maximum dry density, were also tested to determine the remolded shear strength parameters for embankment construction.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Sixth Conference

Publisher

Missouri University of Science and Technology

Publication Date

8-11-2008

Document Version

Final Version

Rights

© 2008 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Aug 11th, 12:00 AM Aug 16th, 12:00 AM

Characterization of Piedmont Residual Soil and Saprolite in Maryland

Arlington, Virginia

Residual soils in the Eastern Piedmont Physiographic province are difficult to characterize because of the unique mineralogy and development of the soils. They are derived in place by weathering of the underlying gneiss and schist bedrock, and are characterized by a gradual transition from soil to decomposed-rock to rock with no clear demarcation between the strata. The soils generally consist of low plasticity micaceous clayey silts, sandy silts and silty sands. It is often difficult to obtain undisturbed samples of these soils and Intermediate Geo-Materials, so most shear strength and compressibility properties are derived from experience or correlations with index parameters such as the SPT N-value and Atterberg limits. For the State of Maryland’s Intercounty Connector (ICC) Project, the General Engineering Consultant (GEC), Intercounty Connector Corridor Partners (ICCCP) Joint Venture working directly for the Maryland State Highway Administration (MSHA), performed a Preliminary Geotechnical Subsurface Exploration (PGSE) during the procurement phase so that the Design-Build (DB) teams would develop preliminary designs on which to base their technical and price proposals. As part of the PGSE performed by the GEC for Contract A of the ICC, several undisturbed samples were obtained so that the shear strength parameters could be determined on relatively undisturbed samples. An attempt was made to correlate the SPT N-values and laboratory testing with seismic refraction geophysical exploration to estimate engineering parameters for design of cut slopes, shrink/swell, a cut/cover tunnel, and several bridges for the three general strata. Not only were undisturbed samples tested to determine the shear strength parameters, remolded samples, compacted to 95% of the modified Proctor maximum dry density, were also tested to determine the remolded shear strength parameters for embankment construction.