RECENT APPLICATIONS OF GRS TECHNOLOGY TO MITIGATE NATURAL DISASTERS IN JAPAN

摘要

The construction of permanent geosynthetic-reinforced soil (GRS) retaining walls (RWs) with a full-height rigid facing for railways, including high-speed train lines, started about twenty five years ago in Japan. The total length of this type of GRS RWs is now more than 125 km, replacing conventional gravity-type RWs or cantilever reinforced concrete RWs and steel-reinforced soil RWs. Many were also constructed to replace conventional type RWs and embankments that collapsed during recent earthquakes, heavy rains, floodings and storms. It is proposed to construct GRS coastal dikes with lightly steel-reinforced concrete facing connected to geosynthetic reinforcement layers as a tsunami barrier. By taking advantage of this technology, a number of bridge abutments with geosynthetic-reinforced backfill were constructed. The latest version, called the GRS integrated bridge, comprises a continuous girder integrated to a pair of RC facing, not using bearings, while the backfill is reinforced with geosynthetic reinforcement layers firmly connected to the back of the facings. The advantages of the GRS integral bridge are presented. It is proposed to apply this new bridge technology to the restoration of conventional type bridges that collapsed by earthquakes, floodings and tsunamis, as well as new construction of those that are highly resistant against these natural disasters.