SEDL / STP / STP1213-EB / STP13206S

Crosshole SH-Wave Measurements in Rock and Soil

Roblee, CJ
Civil Engineer, Caltrans, Office of Geotechnical Engineering, Sacramento, CA

Stokoe, KH
Professor, and Associate Professor, University of Texas, Austin, TX

Fuhriman, MD
Geotechnical Engineer, Fugro-McClelland (Southwest), Inc., Houston, TX

Nelson, PP
Professor, and Associate Professor, University of Texas, Austin, TX

Pages: 15    Published: Jan 1994

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Abstract

A method for in situ measurement of horizontally-polarized shear (SH) waves using the crosshole configuration is discussed. The unique feature of this method is that SH-waves are generated using the directional properties of a stress-wave field produced by an in-hole impulsive source. The source is oriented perpendicular to the alignment of the borehole array and directly impacts a small area of the borehole wall to produce the directional wave field. General tool configurations along with typical data for various geologic materials are presented for each of two operational sources which make use of this concept. One tool utilizes a stack of piezoelectric wafers as its active element. This source generates a high-frequency (1 to 25 kHz) signal which is appropriate for measurement within stiff materials such as rock. The other tool utilizes a solenoid as its active element and generates a low frequency (50 to 1000 Hz) signal which is appropriate for measurement within soil profiles. The inter-relationships between the SH-waves generated here and polarized shear waves using other sources and survey-configurations are also discussed.