Feasibility Study of an Active Sensing Approach to Detect Soil Slope Interlayer Slide Using Piezoceramic Buzzers

Abstract

For soil slope, interlayer slide along the soil-rock interface is the precursor and cause of large-scale landslide disasters. Deep stability status in the slope body is crucial and has always been highly valued in geotechnical engineering. Real-time monitoring of soil-rock interface and early warning of landslide disaster is of great importance for landslide disaster prevention, mitigation and relief. In order to explore the evolution process of the soil-rock interface from stability to slippage, a physical model test at conventional gravitational acceleration condition was performed in laboratory. In this study, an innovative active sensing approach based on four piezoceramic buzzers that attached on an aluminum bar was proposed to detect the soil slope interlayer slide. Among the four buzzers, one was employed as an actuator to generate stress wave, while other three were acted as sensors to receive the propagated signals. The installation of transducers, fabrication of the slope model and monitoring system were presented in detail. During the test, a horizontal thrust was applied on the trailing edge of the slope model using a hydraulic jack. The interlayer slide behavior was then carefully monitored by the propagated stress waves. It was found that the measured stress waves in both time and frequency domain had a negative correlation with the slope sliding distance. It can be attributed to that the interlayer slide attenuates wave energy and then decreases the signal intensity. Additionally, a wavelet packet analysis was employed to develop a slope slide index to evaluate the soil-rock interlayer slide. Experimental results demonstrated that the proposed method is novel yet effective for soil slope interlayer slide monitoring.