Design and verification of a wireless sensing system for monitoring large-range ground movement

Abstract

In this study, flex sensors and Bluetooth wireless transmission technology were combined to fabricate a wireless sensing system for monitoring ground movement. A typical hinge joint structure was designed and fabricated to embed flex sensors. A number of these typical hinge joint elements were used to measure distributed ground movement. Calibration tests show that minimum resolution, sensitivity, and measurement range of flex sensors were 0.5°, 2.0–2.3 count/° and −30°∼+70°, respectively. In experimental study, five flex sensors were placed inside a slope model for both soil settlement and horizontal displacement measurement. Calculated settlement of the data measured from flex sensors were verified with the output data of Linear Variable Displacement Transducer (LVDT), and the obtained maximum errors were less than 0.5 mm when the maximum ground displacement was approached. Besides, the calulated horizontal soil displacement from measurement of flex sensors has proved that flex sensors can be applied for monitoring soil movement when large ground deformation occurs.