Fundamental Penetration Mechanisms of a Flat-Plate in Saturated Clays
Abstract
Flat-plate penetrometers, have become an important part of in situ testing in geotechnical engineering. However, use of flat-plate penetrometers has been highly empirical, mainly due to the lack of knowledge of soil response to the flat-plate penetration. In this project, a numerical technique capable of computing strain paths for three-dimensional penetrometers was developed. A calibration chamber system for cohesive soils and model flat-plates were fabricated. Three dimensional strain path analyses were performed for several of the flat-plate penetrometers currently being used. Results show that flat-plates can induce large strains and strain reversals at levels comparable to those of cone penetration. The characteristics of the strain field during a flat-plate penetration is influenced by both the w/t ratio and the tip apex angle. Regardless of the geometry, the pore pressure and total stress peak at the tip of the penetrometer. The pore pressure and total stress decrease sharply as the soil element passes the tip of the flat-plate. The pore pressure and total stress around the flat-plate do not increase with the plate thickness as some had suggested. For a simple flat-plate (i.e., the flat Marchetti dilatometer), the penetration-induced pore pressure is positively related to the soil rigidity index in the horizontal direction. The excess pore pressure dissipation around the flat-plate in an anisotropically consolidated clay follows an axisymmetric pattern.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 28, 1990
- Accession Number
- ADA227018
Entities
People
- An-bin Huang
- Anurag Ahuja
- Robert D. Bunting
Organizations
- Clarkson University