The majority of the Landslide Early Warning Systems (LEWS) currently in operation are based on the monitoring of rainfall data alone and this limits their performance due to false alarms generated by rainfall thresholds that are inevitably set conservative. The accuracy of LEWS may be significantly enhanced by monitoring soil-based variables associated with the stress-strain response of the ground. This paper investigates whether slope pre-failure deformation can be used as additional precursor of landslide initiation. This would lead to a substantial improvement of LEWS accuracy especially if pre-failure deformation is combined with suction monitoring. Tests were carried out using a small-scale physical model of a slope built with unsaturated volcanic silt subjected to artificial rainfall. A new device named tensio-inclinometer was purposely developed to monitor simultaneously suction and suction-induced deformation. It combines a conventional tensiometer and an accelerometer installed at the top of the tensiometer shaft. It is shown that pre-failure deformation detected by the tilting of the tensiometer shaft is an adequate landslide precursor and that, combined with suction, can provide soil-based thresholds for early warning systems.

目前运行的大多数滑坡预警系统 (LEWS) 仅基于对降雨数据的监测，这限制了它们的性能，因为降雨阈值会产生错误警报，而这些阈值不可避免地被设定为保守的。通过监测与地面应力-应变响应相关的基于土壤的变量，LEWS 的准确性可以显着提高。本文研究了边坡破坏前的变形是否可以作为滑坡萌生的额外前兆。这将导致 LEWS 精度的显着提高，尤其是在故障前变形与吸力监测相结合的情况下。使用人工降雨的非饱和火山淤泥建造的斜坡的小规模物理模型进行了测试。专门开发了一种名为张力倾角仪的新设备，用于同时监测吸力和吸力引起的变形。它结合了传统的张力计和安装在张力计轴顶部的加速度计。结果表明，通过张力计轴倾斜检测到的破坏前变形是充分的滑坡前兆，并且与吸力相结合，可以为早期预警系统提供基于土壤的阈值。