ISSN: 0149-6115
Published Online: 6 August 2007
Page Count: 12

A Suction-Control Apparatus for the Measurement of P and S-wave Velocity in Soils

Alramahi, Bashar
Graduate Student,Civil and Environmental Engineering; Louisiana State University,

Alshibli, Khalid A.
Joint Associate Professor,Civil and Environmental Engineering; Louisiana State University-Southern University,

Fratta, Dante
Assistant Professor,Civil and Environmental Engineering and Geological Engineering; University of Wisconsin-Madison,

Trautwein, Stephen
President,Trautwein Soil Testing Equipment Company,

(Received 20 May 2006; accepted 17 June 2007)

Abstract

This paper presents a new apparatus for the measurement of P and S-wave velocities in unsaturated soil specimens under controlled net stress and matric suction conditions. The system consists of a triaxial cell modified to enable an independent control of the pore air and water pressures as well as the confining pressure, and to accommodate P and S-wave sources and receivers. The system also includes three servo-controlled pressure pumps, and a computer control system that drives the pressures and acquires volume changes. Three sets of experiments were conducted to verify the system performance. Specific matric suction values were applied while monitoring the stabilization process of capillary pressures using the P and S-wave velocity measurements. Both P and S-wave velocities increase due to the rise in interparticle forces resulting from the increase in matric suction.

Keywords:
unsaturated soils, matric suction control, non-destructive testing, elastic wave propagation, small-strain stiffness

Paper ID: GTJ100646
DOI: 10.1520/GTJ100646
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