Investigation on Surface Tilting in the Failure Process of Shallow Landslides

Abstract

In recent decades, early warning systems to predict the occurrence of landslides using tilt sensors have been developed and employed in slope monitoring due to their low cost and simple installation. Although many studies have been carried out to validate the efficiency of these early warning systems, few studies have been carried out to investigate the tilting direction of tilt sensors at the slope surface, which have revealed controversial results in field monitoring. In this paper, the tilting direction and the pre-failure tilting behavior of slopes were studied by performing a series of model tests as well as two field tests. These tests were conducted under various testing conditions. Tilt sensors with different rod lengths were employed to investigate the mechanism of surface tilting. The test results show that the surface tilting measured by the tilt sensors with no rods and those with short rods located above the slip surface are consistent, while the tilting monitored by the tilt sensors with long rods implies an opposite rotational direction. These results are important references to understand the controversial surface tilting behavior in in situ landslide monitoring cases and imply the correlation between the depth of the slip surface of the slope and the surface tilting in in situ landslide monitoring cases, which can be used as the standard for tilt sensor installation in field monitoring.

Observations on soil-atmosphere interactions after long-term monitoring at two sample sites subjected to shallow landslides

“…Moreover, since the test sites are prone to rainfall-induced shallow landslides, whose development is strongly related to soil hydrological conditions, we will deepen the relationship between the field monitored data and the initiation or evolution of the shallow landslides, integrating also meteorological and hydrological time series with monitoring of displacements, tilting in shallow soil layers and lateral deformations (e.g. Qiao et al 2020).…”

MEMS technology and applications in geotechnical monitoring: a review

“…Using monitoring result of two sites, it is suggested that MEMS tilt sensors are an appropriate alternative of conventional extensometer in monitoring of tilt angle in surface layers with depth of 0.75 m [15]. This is a great achievement since traditional landslide protection strategies, such as retaining walls and/or earth anchors/piles, are costly and not effective for all scales of landslides [87].…”

Internet of Things Geosensor Network for Cost-Effective Landslide Early Warning Systems

“…As the exact geometry of the landslide is unknown, SN measurements can only semi-quantitatively monitor landslide movement. These mechanics are also described by Qiao et al (2020) who explored the direction and pre-failure tilting behavior of slopes and how this affects measured tilting angles of steel rods of different sizes [60,67]. As stated earlier, the sensor placement should generally be adapted according to the previously performed risk analysis.…”