A Fundamental Study of the Field Compressometer Test.

Abstract

The project consisted of both theoretical and experimental research components. The theoretical research involved the development of a simple elasto-plastic constitative model based on incremental plasticity and double-hardening concepts to model the behavior of geomaterials. The model has been tested under general loading conditions and has reproduced experimental results reasonably well. I has also been implemented in a finite element program to facilitate the analysis of practical soil-structure interaction problems such as the screw-plate compressometer (SPC) test. An optimization scheme has been developed to aid in parameter identification. Significant improvements in the test equipment and experimental procedures were made in order to take advantage of the SPC's full potential. Initial laboratory work indicated that the use of small load increments and low strain levels provided useful data for interpreting soil response to buried circular plates similar to the field compressometer. Proof testing indicated that the new drill rods and a tension cable reference system performed very well, and installation was much simpler and faster man previously. The deformation measuring system was improved The interaction of the drilling rods with the surrounding soil was an important factor in prototype field SPC testing. Soil stiffness and strength was found to control the load reaching the plate, and the stiffness of the soil controlled plate deformations. The load to the plate generally varied with time, depending on the rate of deformation and the relative stiffness of the various soil components. The use of friction reducers or drilling mud may reduce, but not entirely eliminate; the effect of friction. Such methods would also complicate the test.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Dec 08, 1995
Accession Number
ADA310019

Entities

People

  • R. D. Holtz
  • Srutarshi Banerjee

Organizations

  • University of Washington

Tags

Communities of Interest

  • Air Platforms
  • Human Systems

DTIC Thesaurus Topics

  • Air Force
  • Civil Engineering
  • Composite Materials
  • Control Systems
  • Data Acquisition
  • Elastic Properties
  • Finite Element Analysis
  • Geotechnical Engineering
  • Measurement
  • Mechanics
  • Plastic Properties
  • Pressure Measurement
  • Shape
  • Soil Structure Interactions
  • Stress Strain Relations
  • Test Equipment
  • Three Dimensional

Fields of Study

  • Engineering

Readers

  • Geotechnical Engineering.
  • Mechanical Engineering/Mechanics of Materials.
  • Systems Analysis and Design