Abstract
This paper describes the design, fabrication, and initial testing of an instrumented flat dilatometer test (iDMT) device. Compared to the DMT test involving pressure readings at two fixed displacements, this device is designed to have a direct displacement-measuring system and a larger displacement range to evaluate the continuous pressure-displacement relation of a soil, which may afford an opportunity to improve the interpretation to take non-linear soil behaviors into account rather than using linear elasticity in the DMT analysis. However, technical constraints are encountered in the iDMT blade machining using traditional technologies; alternatively, a 3D printing technology is successfully applied to fabricate the iDMT blade. Then, the calibrations of the iDMT device are performed, followed by an iDMT test in conjunction with a DMT test in a calibration chamber, demonstrating that the new iDMT device can be used to investigate non-linear soil behaviors, and the 3D printing technology is proved not only to be an expedient solution but also to be used as a routine tool in improving geotechnical testing apparatus.
