The southern part between Shin-Aomori Station (at the north end of Main Island) and Shin-Hakodatehokuto Station (at the south end of Hokkaido Island) of a new high-speed train line called Hokkaido Shinkansen was nearly completed by the end of 2014 and will be opened in 2016. In a range of 37.3 km at the south end of Hokkaido Island, a number of various types of geosynthetic-reinforced soil (GRS) structure were constructed: i.e., 1) GRS retaining walls (RWs) having full-height rigid facing for a length of about 3.5 km, having fully replaced the conventional type RWs; 2) in total 29 GRS bridge abutments, having fully replaced the conventional type bridge abutments; 3) a GRS integral bridge, the world-first one at Kikonai; 4) three GRS box culvert structures integrated to adjacent GRS RWs; and 5) nine GRS protection structures at the tunnel entrance. These GRS structures have been constructed most densely ever for railways, which is definitely so for high speed trains. This paper describes the design and construction of these GRS structures with several lessons learned from this project are summarized.
