Details:

Alternative Title:
Technical report 15-12 : correlation of engineering parameters of the presumpscot formation to the seismic cone penetration test (SCPTU).
Creators:
Hardison, Mathew A. ; Landon, Melissa L.
Hardison, Mathew A. ; Landon, Melissa L. Less -
Corporate Creators:
University of Maine. Advanced Structures and Composites Center
Corporate Contributors:
Maine. Dept. of Transportation. Transportation Research Division
Subject/TRT Terms:
[+]
Engineering Geology Geotechnical Engineering Presumpscot Clay Seismic Cone Penetration Test Soil Mechanics Soil Penetration Test Soil Tests Stress Tests (Equipment)
Resource Type:
Thesis
Geographical Coverage:
United States ; Maine
United States ; Maine Less -
Corporate Publisher:
Maine. Department of Transportation. Transportation Research Division
Abstract:
The seismic cone penetration test with pore pressure measurement (SCPTu) is a geotechnical investigation technique which

involves pushing a sensitized cone into the subsurface at a constant rate while continuously measuring tip resistance, sleeve

friction, and pore pressure resulting from soil shearing. Additionally, shear wave velocity measurements can be collected at

discrete intervals throughout the test. Empirical and theoretical correlations have been developed between these measurements

and soil engineering properties such as preconsoldiation pressure and undrained shear strength. Soil classification, location of

silt/sand seams, seismic design parameters, and liquefaction potential can also be obtained from SCPTu results.

The objective of this study is to evaluate the SCPTu as a tool to predict engineering properties of the Presumpscot Clay. When

paired with conventional borings, the SCPTu can provide a more comprehensive understanding of the subsurface, help refine

geotechnical analyses and give engineers access to continuous stratigraphy and engineering parameters throughout an entire

deposit rather than at discrete sampling depths common for conventional field vane shear tests (FVT) and boring investigations

for the deposit.

Four locations where the Presumpscot Formation exist in Maine were selected for investigative and laboratory testing programs.

At each location, SCPTu and conventional borings were conducted. During the conventional borings, field vane shear tests were

performed and Shelby tube or Sherbrooke block samples were collected for laboratory testing at 5 foot depth intervals. High

quality samples were analyzed in the laboratory to determine index properties, consolidation behavior, and undrained shear

strength characteristics. With these results, published correlations of SCPTu results to engineering parameters were verified and

refined for the Presumpscot Formation.

Findings from the study indicate that predicting classification of the Presumpscot clay from CPTu classification charts is best

performed using Robertson (1990) and Schneider et al.,(2008), both of which use the relationship between normalized tip

resistance and normalized pore pressure. Applying a k-value of 0.33 to measurements of tip resistance provides a reasonable

estimate of preconsolidation pressure and OCR at any depth. CPTu cone factors Nkt and N・u, used to estimate undrained shear

strength, were higher for the Presumpscot clay than most suggested values from similar studies in clay. Furthermore, su

determined from triaxial compression versus direct simple shear caused a difference in both Nkt and N・u of at least 5.0. Sitespecific

correlations resulted in the best CPTu correlation to engineering properties of the Presumpscot clay.


Format:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:830531b13833340d31d9b569b07d4084f816eed828f79777d7e1a21b53267c22
Download URL:
https://rosap.ntl.bts.gov/view/dot/31350/dot_31350_DS1.pdf
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