Experimental analysis of the feasibility of deep slide monitoring with low-cost piezoelectric diaphragms-based EMI technique

Slope instability, especially the soil slope instability, is a common occurrence in mountainous areas. It poses a huge threat to people's lives and properties under the slope body. Effective slope monitoring techniques can provide detailed information and precursor about the real-time deformation, which is of great importance to provide early warning to the public. In this paper, a novel electromechanical impedance (EMI)-based slope deep slide monitoring bar (DSMB) was proposed. The main purpose was to investigate the application of the EMI technique for deep slide detection. In this study, a small soil slope specimen with a DSMB embedded inside it was fabricated in laboratory. To verify the practicality of the low-cost piezoelectric diaphragms (commonly known as buzzers), four conventional lead zirconate titanate (PZT) patches and four buzzers were bonded onto the front surface and back surface of the bar at specific positions, respectively. The slope specimen was then subjected to a horizontal thrust to initiate an interlayer slide along the slip surface. The whole process was monitored with a precision impedance analyzer by measuring the admittance of these transducers at specific sliding displacement. In order to reduce the error and increase the reliability, the experiment was repeated three times under the same conditions. It was concluded that the conventional PZT patches and buzzers have similar sensitivities to interlayer slide damage. The results indicate that both the severity and sliding location could be identified via the two metrics including root mean square deviation (RMSD) and correlation coefficient deviation (CCD). The experimental results verify the feasibility and practicality of using novel and low-cost piezoelectric diaphragm-based EMI technique to detect the deep slide in soil slope.