Acoustic emission distress monitoring in sensitive clay

Abstract

A commercial acoustic emission monitoring system (Model MS-1 Geo-monitor) was used to record acoustic emissions in undisturbed block samples of Champlain Sea clays that were deformed to a passive failure state in the laboratory. Laboratory cast samples of Ottawa sand, washed concrete sand, remoulded kaolin clay, and remoulded Champlain Sea clay were also used in order to correlate the acoustic response of various soils. The Geo-monitor system was capable of detecting and quantifying acoustic emissions in all soils tested. Acoustic emissions associated with failure in the coarse-grained soils ranged from 50 to 200 emissions per minute at an amplification of 1000 times. In the fine-grained soils, an amplification of 10 5 times was required and acoustic emissions of up to 25 emissions per minute were recorded under passive failure conditions. Keywords: acoustic monitoring, slopes, sensitive clay, laboratory study.