Indoor Tests of Sensor-Enabled Piezoelectric Geocable–Geogrid Composite Structure for Slope Rehabilitation and Monitoring

Abstract

Geosynthetic materials are commonly used to reinforce soil structures and prevent geological disasters in engineering. Meanwhile monitoring soil reinforcement is essential for ensuring safe engineering activities. Few structures can effectively serve both functions. Therefore, this study combined a sensor-enabled piezoelectric geocable with a geogrid to obtain a sensor-enabled piezoelectric geogrid (SPGG) based on the impedance–strain relationship. Tension, pullout, and straight shear tests were conducted on this SPGG configuration. The tension test results indicated that the tensile strain–normalized impedance curves were exponential in form over the first 7% of strain and the rate of change in impedance was independent of the tension loading rate. Excellent correspondence between the peak strength and impedance inflection point was observed in the pullout and straight shear test results. Further validation of the proposed SPGG was performed using a reinforced soil slope model collapse test. The results indicated that the SPGG-obtained strains were similar to actual strain gauge measurements but provided a larger measurement range and that the SPGG was able to sense real-time vibrations during the slope collapse using a voltage analysis, confirming that the proposed SPGG can simultaneously provide soil reinforcement, strain monitoring of reinforcement materials, and vibration sensing. This research is expected to inform the development of a distributed, large range, and accurate method for monitoring the conditions of reinforced soil over their entire lifecycles.

Keywords: Reinforced soil slope, Distributed monitoring, Sensor-enabled piezoelectric geogrid (SPGG), Piezoelectric effect, Impedance strain effect