A literature review about the deployment of accelerometers as non-seismic soil landslide tilting sensors

Monitoring is an element of landslide early warning systems. Fukuzono’s method, based on displacement and velocity monitoring, is one of the most popular methods for slope time of failure (TOF) prediction. This critical literature review aimed to systematically analyze the state-of-the-art accelerometers used for slope monitoring and TOF prediction. Two peer-review online article platforms were used to build a database of 50 articles. Time history analysis showed that from 2014 onwards the interest in accelerometers has increased and using them as tilt sensors has become a well-accepted approach for geotechnical monitoring. However, special attention must be paid to calibration and noise reducing of low-cost sensors. Also, the installation setup may influence measurements. Alert thresholds and TOF prediction methods based on tilting rates for sensors buried at shallow depths have been proposed and few real validated cases are reported. These predictions attempt to find a simple relation between TOF and slope tilting rate, similar as Fukuzono’s method. Relations between tilting rate and surface displacement is an aspect that remains unclear. In order to clarify those aspects, more real slope cases should be reported. A more established use of accelerometers is as a chain of sensors buried in a borehole, similar to a permanent inclinometer. In these cases, accelerometer data are interpreted as displacement, in a more traditional way.

Keywords:
Geotechnical monitoring; Landslide early warning system; Time-of-failure prediction; Tilt angle