In Situ Constitutive Relations of Soils and Rocks.
Abstract
Current results of an ongoing SRI program to determine dynamic in situ stress-strain response at field sites are presented. The method used was the LASS technique (Lagrange analysis for stresses and strains). In this technique field measurements of radial stress and particle velocity histories induced by explosive loading are combined with a numerical analysis to solve the governing partial differential flow equations for the desired stress and strain trajectories. The first successful LASS field test, performed as an add-on to the WES CENSE II series, yielded reasonable radial stress-volume strain load-release paths for the CENSE II site material. Experimental and analytical studies of the mutual inductance particle velocity gage indicated that gage response can be improved by modifying the power supplies and that emplacing the gages in radial grout columns is acceptable. The analysis was refined and demonstrated to be capable of calculating stress-strain trajectories accurate to the 5 to 10 percent, given high quality stress and particle velocity histories from 5 to 8 gage locations. Shear response calculations are not yet satisfactory, but possible improvements are discussed. The major conclusion of this effort is that the LASS technique is ready for field use at sites of interest. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1976
- Accession Number
- ADA064123
Entities
People
- C. W. Smith
- Damian Curran
- J. T. Rosenberg
Organizations
- SRI International