United States Department of Transportation
ROSA P serves as an archival repository of USDOT-published products including scientific findings, journal articles, guidelines, recommendations, or other information authored or co-authored by USDOT or funded partners.
As a repository, ROSA P retains documents in their original published format to ensure public access to scientific information.
i
Correlation of engineering parameters of the presumpscot formation to the seismic cone penetration test (SCPTU).
-
2015-08-01
Details:
-
Alternative Title:Technical report 15-12 : correlation of engineering parameters of the presumpscot formation to the seismic cone penetration test (SCPTU).
-
Creators:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Resource Type:
-
Geographical Coverage:
-
Corporate Publisher:
-
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:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type:
[PDF-8.19 MB]
