Use of Soil Stiffness Gauge in Thermoplastic Pipe Installation

Abstract

The soil stiffness gauge is a new tool for measuring the stiffness of a soil layer quickly in the field. It is anticipated that this type of portable device will be utilized in a variety of geotechnical projects in the future, since stiffness is a better indicator of the quality of soil fill than dry density. This paper examines the usefulness of the soil stiffness gauge in thermoplastic pipe installation work. Comprehensive data obtained during the initial stage of the thermoplastic pipe deep burial project in Ohio are reviewed to discuss the ability of the soil stiffness gauge to realistically measure the stiffness of the backfill soil placed around thermoplastic pipe and the ability of the soil modulus derived from the soil stiffness gauge readings to predict the horizontal deflections of the thermoplastic pipe under moderate to deep soil cover.