Development of a Large-Scale Triaxial Testing Device for Wave Propagation Studies.
Abstract
Experimental and analytical studies have been undertaken to investigate the effects of the 3-D state of stress on the characteristics of seismic waves in soil. The initial experimental studies involve testing instrumented cubes of dry sand where the principal normal stresses are controlled independently. Compressing (P) and shear (S) waves are generated on the sides of the sand cube and propagate through the body of the sand. Wave lengths and frequencies are in the range of 0.5 to 2.0 ft and 300 to 1000 Hz, respectively. Accelerometers embedded in the sand body are used to monitor wave arrivals and amplitudes from which propagation velocities and attenuation under the various states of stress are calculated. The design and fabrication of the experimental facilities are presented. A metal-walled cube has been constructed with rubber membranes to apply confining pressures. In the center of each wall are excitation ports where impulses are applied to excite P- and S-waves in the sand at shearing strains below 0.01 percent. Analytical studies have concentrated on evaluating the disturbance created by an accelerometer, considered as a rigid body, on the wave front travelling through the soil. Two different approaches have been considered: the boundary integral equation method and a finite element formulation. Results are presented. The work described herein represents the first step in a long-range program to investigate experimentally the dynamic behavior of soils under arbitrary states of stresses and to study analytically the most appropriate procedures to model this behavior. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1980
- Accession Number
- ADA093400
Entities
People
- C. Suddhiprakarn
- D. P. Knox
- J. M. Roesset
- K. H. Stokoe
- S. E. Kopperman
Organizations
- University of Texas at Austin