The RRR CONSTRUCTION SYSTEM (Reinforced Road with Rigid Facing Construction System) is a reinforced soil construction system developed jointly by the Railway Technical Research Institute and the Institute of Industrial Science, University of Tokyo. It consists of reinforced soil structures characterized by a full-height rigid facing to which many layers of planar reinforcements or several medium to large diameter reinforcements are firmly connected. Those structures have exhibited a high stability against numerous past severe earthquakes and heavy rainfalls or tsunamis while being more cost-effective than conventional structures, thus have become the standard reinforced soil structures for conventional and high-speed railways in Japan. Four types of structures have been developed so far: RRR-A (Geosynthetic-reinforced soil (GRS) bridge abutments and GRS integral bridges), RRR-B (GRS retaining walls), RRR-C (Nail reinforced soil retaining walls), and RRR-D (GRS river and coastal dykes to prevent water-front disasters).

The RRR Association was established in 1991 to promote and develop the RRR construction system, and comprises 66 corporate members that include general contractors, design consultants, and material manufacturers.

Document Download (PDF)