Development of a Continuous Intrusion Miniature Cone Penetration Test System for Subsurface Explorations

Abstract

This paper describes the development of a continuous intrusion miniature cone penetration test system (CIMCPT) for shallow to semi-deep subsurface investigations. A novel feature of this new in situ testing system is the chain driven caterpillar-type continuous push device powered by a hydraulic motor to advance the cone penetrometer, which greatly increases productivity and serviceability. The system is housed in an environmentally controlled van body that is mounted on a one-ton, four-wheel drive, all-terrain vehicle. A new state-of-the-art data acquisition system using interface modules and a global positioning system, for real-time monitoring, acquiring, storing, and displaying data in real time on a computer screen in graphic form was developed and implemented. The miniature cone penetrometer has a projected cone area of 2 cm2 and a friction sleeve surface area equal to 40 cm2. It gives finer detailed soil profiles compared to the standard 10 cm2 cross-sectional area reference cone penetrometer. In situ calibration of the CIMCPT system with the standard 10 cm2 cone penetrometer indicated that the average tip resistance of the CIMCPT was 11 percent higher than that of the standard cone penetrometer. The average CIMCPT sleeve friction was 11 percent lower than that of the standard cone penetrometer.