| This paper discusses the detection of hidden deteriorations, deteriorations at invisible places on visual inspections, of reinforced soil walls (RSWs).The presence or absence of inspection methods which can detect the hidden deteriorations in daily inspections is important to make the shift to preventative maintenance. The fault tree discloses some difficult deteriorations events to detect by a visual inspection. Cavity of subsurface soil, fracture of reinforcement material, corrosion of reinforcement material, high tension of reinforcement material, and disappearance of filter fabric are hidden deterioration events. In these events, the cavity has a potential to cause road sag and the fracture has a potential to cause wall’s fall. The road sag could lead to vehicle accident. The wall’s fall could lead to not only third party damages but also destabilization of RSWs because of leakage of soil. Applicability of maintenance method to detect the cavity or the fracture on detail surveys after grasping signatures of the cavity or the fracture on daily inspections was confirmed by full scale model tests. Two types of reinforced soil wall were constructed at the Public Works Research Institute test pit. One was the geogrid type, and the other was terre armee type. Cavity of subsurface soil and fracture of reinforcement material were artificially-generated to each type of reinforced soil walls. Ground penetrating radar (GPR) and electrical resistance (ER) survey were conducted before and after generation of cavity. Vibration property of walls was analyzed before and after fractures of reinforcement materials. It was verified that GPR, ER, and vibration property of walls could detect hidden deteriorations. |
