A Fundamental Investigation of Crack and Surrounding Damage in Stiff Clays
Abstract
The geotechnical engineering profession is quite familiar with stiff fissured and jointed clays where discontinuities are found on a macroscopic scale. however, there has not been, until recently, a systematic investigation of the crack propagation phenomena involved in the failure of such clays. This study presents the first phase of an investigation whose aim is to understand, describe and quantify the mechanisms involved in crack propagation. The experimental investigation indicated that in front of the crack. In this zone the structure of the clay is shown to be substantially altered. An image analyser is used to quantify the damage which appears as densified strips. Such strips result from the coalescence of clusters of clay particles which are uniformly distributed in the virgin material. Fracture is treated as an irreversible process within the framework of thermodynamics. A damage parameter is introduced and an equation of state is written in terms of entropy production. A generalized flux is identified as the centroidal movement of the damage zone, and the active part of the thermodynamic force is compared to the conventional J integral. Stress and energy analyses for the damage zone are performed. A constitutive model for describing the fracture is proposed. Keywords: Stiff clay; Damage propagation; Strip densification; Stress analysis; Energy balance; Constitutive model.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1988
- Accession Number
- ADA204053
Entities
People
- A. Lesser
- Adel S. Saada
- Alexander Chudnovsky
Organizations
- Case Western Reserve University