Seismic design, construction and performance of geosynthetic-reinforced soil retaining walls and bridge abutments for railways in Japan

摘要

Permanent geosynthetic-reinforced soil (GRS) retaining walls (RWs) with staged-constructed full-height rigid (FHR) facing for railways, including high-speed train lines, and motorways and others have been constructed for a total length of more than 135 km in Japan. A series of small and full-scale model tests and numerical analyses were performed for the last nearly three decades to develop this technology. During the 1995 Kobe and the 2011 Great East Japan Earthquakes, a number of GRS RWs of this type performed very well. A number of embankments and conventional type RWs that collapsed by these and other earthquakes, as well as heavy rains and floods, were reconstructed to GRS RWs of this type. Based on this technology, the GRS integral bridge system was developed, which comprises a continuous girder integrated to a pair of RC facing not using bearings and backfill reinforced with geogrid layers firmly connected to the facings. The first prototype was constructed in 2011 - 2012 for a new high-speed train line in Hokkaido, Japan. This technology will be used to reconstruct two conventional type bridges that fully collapsed by tsunami during the 2011 Great East Japan Earthquake and to newly construct bridges to be highly cost-effective while highly seismic-resistant.