Accession Number:

ADA415896

Title:

A Statistical Micromechanical Theory of Cone Penetration in Granular Materials

Descriptive Note:

Technical rept.

Corporate Author:

ENGINEER RESEARCH AND DEVELOPMENT CENTER HANOVER NH COLD REGIONS RESEARCH AND ENGINEERING LAB

Personal Author(s):

Report Date:

2003-02-01

Pagination or Media Count:

42.0

Abstract:

A micromechanical theory of cone penetration in granular material is developed that takes into account the effects of soilpenetrometer friction, material compaction, and the statistics of microstructural element failure. Microstructural elements elements consist of particles connected to each other by cohesive or friction contacts. Soilpenetrometer friction and the deformation and failure of elements in contact with the penetrometer effective surface PES cause cone penetration resistance penetration force divided by the cone base area. The PES is the interface surface between the compacted material that forms around a cone penetrometer and the surrounding elements. The cone half-angle and the volume strain at which granular particles from failed elements lock up determine the PES area. The failure of elements during penetration produces a random roughness surface of elements next to the PES. Consequently, a finite probability exists that each element next to the PES will be in contact with it at any time. The probability of contact, dimensions, and failure strength of the elements determines the percentage of elements next to the PES that contribute to penetration resistance. The statistical interaction of elements with the PES causes the maximum penetration resistance to decrease with increasing penetrometer base area, asymptotically approaching the average value. The effects of decreasing soilpenetrometer friction and the increasing PES area as a function of cone half-angle produce a minimum penetration resistance at a cone half-angle of about 15 degrees. Element failure strength is described in terms of elastic-brittle and Mohr-Coulomb models.

Subject Categories:

  • Miscellaneous Materials
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE