Abstract
Many techniques that the strain gauge is stuck on the surface of geogrid have been used to verify the internal stress of the reinforcement soil wall. But, there are many problems in the strain gauge. geogrid laid in the whole surface in the soil is measured from the viewpoint of separation. A lot of strain gauges are necessary to lead the tendency. Wiring becomes complicated, and the measuring cost tends to grow big, too. The life of the strain gauge in the soil is about 2-3 years by the influence of the water and so on. It is possible with the optical fiber that all these problems are dissolved. This paper reports the adaptation result in the field.
