The electric cone penetration test (CPT) has been in use for over 40 years and is growing in popularity in North America. This paper provides some recent updates on the interpretation of some key g...

Interpretation of cone penetration tests — a unified approach

Significant advances have been made in recent years in research, development, interpretation, and application of cone penetration testing. The addition of pore pressure measurements during cone pen...

Interpretation of cone penetration tests. Part I: Sand

Estimation of the axial capacity of piles driven into sand involves considerable uncertainty, and design rules are generally not consistent with the physical processes involved. This Paper reviews current understanding of the factors that determine the axial capacity of piles driven into sand, and outlines a new framework for design which takes account of the physical processes, is consistent with the existing database of load test results, and is sufficiently flexible to permit refinement as new data become available. It allows for the effects of confining stress on the frictional and compressibility characteristics of sand, and hence on end-bearing capacity. In keeping with field observations, shaft friction is assumed to degrade with driving of the pile past a particular location, from an initial maximum value linked to the local end-bearing capacity. The resulting design approach is compared with field data, and effects of factors such as the direction of loading are discussed. L'estimation de la resi...

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Design of driven piles in sand

Existing methods for the evaluation of liquefaction potential using data obtained from the Cone Penetration Test (CPT) are reviewed. A modified CPT‐based method for the liquefaction assessment of sand is presented. Information available on the liquefaction of silty sands is reviewed, and a procedure for considering the influence of silt content is also presented. Field and laboratory data from Canada, Japan, China and the United States are presented to provide a preliminary evaluation of the proposed CPT‐based liquefaction assessment methods.

Liquefaction Potential of Sands Using the CPT

A soil engineering classification derived from the cone penetration test (CPT) involves the uncertainty of correlation between soil composition and soil mechanical behavior. This uncertainty results in overlaps of different soil types in currently used CPT soil classification systems. Accordingly, two statistical soil classification criteria, region estimation and point estimation, are suggested to address this problem. Further, a new fuzzy subset approach is introduced to develop a truly independent CPT soil engineering classification, and to establish a transition between the new fuzzy approach and conventional soil classifications by utilizing local site- and project-specific calibrations. CPT results conducted at the National Geotechnical Experimentation Site at Texas A&M University are used to demonstrate this new CPT soil engineering classification methodology.

B. Douglas

Papers

Soil classificaion using electric cone penetrometer