Constitutive Models for Static and Dynamic Response of Geotechnical Materials

Abstract

The objective of this research program has been to develop realistic macroscopic constitutive relations which describe static and dynamic properties of geotechnical materials (soils and rocks). To this end a coordinated theoretical and experimental activity has been followed. The theoretical work includes a balanced combination of statistical microscopic (at the grain size level) modeling and a nonclassical elasto-plastic macroscopic formulation. The latter includes the effects of internal friction, plastic compressibility, and pressure sensitivity, as well as anisotropy which is commonly observed in geotechnical materials. The following specific goals have been sought: (a) to develop three-dimensional constitutive relations under ordinary or high pressures (such as those induced by blasting or tectonic forces which may cause a large amount of densification by relative motion and possible crushing of grains); and (b) to examine and characterize the behavior of saturated granular materials under dynamic loading. The latter item includes characterization of possible liquefaction and subsidence which may be induced in granular materials under confining pressure by ground vibration or passage of waves. The theoretical work has been carefully coordinated with key experiments in order to: (a) understand the basic physics of the process, both at macroscopic and microscopic levels; (b) to verify the corresponding theoretical predictions; and (c) to establish relevant material parameters.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1983
Accession Number
ADA139293

Entities

People

  • S. Nemat-nasser

Organizations

  • Northwestern University

Tags

Communities of Interest

  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Air Force
  • Civil Engineering
  • Creep
  • Crystal Structure
  • Engineers
  • Failure Mode And Effect Analysis
  • Integral Equations
  • Materials
  • Mechanical Properties
  • Mechanics
  • Modulus Of Elasticity
  • Plastic Flow
  • Plastic Properties
  • Shear Modulus
  • Shear Stresses
  • Stress Strain Relations
  • Temperature Gradients

Readers

  • Geotechnical Engineering.
  • Mechanical Engineering/Mechanics of Materials.
  • Technical Research and Report Writing.