Accession Number : ADA310019

Title :   A Fundamental Study of the Field Compressometer Test.

Descriptive Note : Final rept. 1 Oct 91-14 May 95,

Corporate Author : WASHINGTON UNIV SEATTLE DEPT OF CIVIL ENGINEERING

Personal Author(s) : Banerjee, S. ; Holtz, R. D.

PDF Url : ADA310019

Report Date : 08 DEC 1995

Pagination or Media Count : 119

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.

Descriptors :   *SOIL STRUCTURE INTERACTIONS, *SOIL MODELS, COMPRESSION, STRESS STRAIN RELATIONS, COMPUTER PROGRAMS, MATHEMATICAL MODELS, LOAD DISTRIBUTION, OPTIMIZATION, STRESS ANALYSIS, FINITE ELEMENT ANALYSIS, DEFORMATION, STIFFNESS, FIELD TESTS, SAND, BOUNDARY VALUE PROBLEMS, SHEAR STRESSES, DATA ACQUISITION, PARTIAL DIFFERENTIAL EQUATIONS, BURIED OBJECTS, SOIL DYNAMICS, FRICTION, HARDENING, SOIL TESTS, SOIL SETTLEMENT, FIELD EQUIPMENT, AXIAL LOADS, GRANULAR MATERIALS, CYCLIC LOADS, ELASTOPLASTICITY, SILT, CLAYEY SOILS, LOAD CELLS, OBJECT ORIENTED PROGRAMMING.

Subject Categories : Soil Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE