Field instrumentations for the investigation of the behavior of geotextiles

Full scale trial constructions were performed to verify the deformational characteristics of the polyester mat which was used for the embankment reinforcement and to suggest appropriate installing method of measuring instruments on the geotextile. Various instrumentation equipment including surface settlement plates, hydraulic profile gauges and biaxial inclinometer casings were installed to observe the behavior of the ground under the soil embankment. 60 electrical resistance strain gauges and 9 vibrating wire displacement transducers were installed to measure the deformation of the PET mat directly. After the 2nd stage fill construction(height=3m), 93% of strain gauges and 78% of displacement transducers survived all perils of impact, dust, heavy rainfall, and so forth. Observed strain of PET mat under the 2nd stage embankment load was less than 1%. However, it was obvious that the tensile strain increased as vertical loads became larger.