Measurement Performance Evaluation of Tactile Pressure Sensor with Different Particle Sizes and Sensor Curvatures

In small-scale geotechnical experiments, using a tactile pressure sensor (TPS) to measure soil pressure distribution on a curved surface can effectively reduce errors of mismatch caused by size, stiffness, and incomplete fitting with the measured object. TPS has more benefits than soil pressure cells in measuring curve surface pressure, but some issues remain unclear, such as the effect of negative-piezoresistivity and particle size on the measurement. In this article, the author first puts forward a method to effectively reduce the errors of TPS in the low-pressure measurement zone. Then, through a load test in six types of narrow-graded sand, the ratio of the maximum particle size to the size of the sensor unit is obtained, and the effect of negative piezoresistivity on the measurement is evaluated. Finally, a small laboratory test proves that TPS can comprehensively and meticulously reflect the pressure on the pile. After careful calibration and considering the effect of deflection and particle size, it is shown that the measurement errors can be kept within an acceptable range.