Geosynthetic-Reinforced Soil Structures to Mitigate Natural Disasters

The total length of permanent geosynthetic-reinforced soil (GRS) retaining walls (RWs) with staged-constructed full-height rigid (FHR) facing for railways, including high-speed train lines, highways and so on is now more than 125 km in Japan. Many were also constructed replacing conventional type RWs and embankments that collapsed during recent earthquakes, heavy rains, floodings and storms. It is proposed to construct GRS coastal dikes with FHR facing connected to geosynthetic reinforcement layers as a tsunami barrier. Based on the GRS RW 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, and the \backfill reinforced with geosynthetic reinforcement layers firmly connected to the facing. The advantageous features of this new bridge system are summarized. It is proposed to apply this new bridge system to replace conventional type bridges that collapsed by earthquakes, flooding and tsunami and also to newly construct those having high resistance against these natural disasters.