Development of earthquake-proof road retaining wall and related evaluation method

Abstract

Natural disasters can result in significant damage across the world and leave communities grappling with the social, economic and environmental consequences for years. Developing countries, in particular, can struggle to recover from the damage left in the wake of disasters. A partnership involving academic institutions in Japan is delving into the capacity of gabion structures to provide improved natural disaster protection for communities in developing countries.For this project Japan’s National Research Institute for Earth Science and Disaster Resilience (NIED) is working alongside Kochi University and Saga University as well as industrial partners comprising two design consultants, a manufacturer and a construction company, and also Tribhuvan University in Nepal, who coordinate the in-country work. Professor Hiroshi Nakazawa, who heads up NIED’s Department of Earthquake Disaster Mitigation and is leading the team, is focused on both project coordination and estimating the earthquake resistance of gabion retaining wall using a full-scale model test. Nakazawa’s colleague Professor Tadashi Hara of Kochi University is tasked with completing a factor analysis on gabion retaining wall based on damage survey and proposal for construction of improved gabion wall in Nepal, and another colleague Professor Daisuke Suetsugu of Saga University is undertaking a fundamental study of gabions through laboratory tests and evaluation of the advanced design method. Nakazawa outlines that after the 2015 Nepal earthquake, the team had an opportunity for earthquake reconnaissance which really kicked off their latest study. ‘We investigated a large number of ground disasters in mountain areas and noticed there are many gabion structures used as retaining wall and guard rail along a highway. In light of this, we determined the subject of our research would be establishing reasonable construction procedures and guidelines on a seismic gabion structure and this would be based on its actual use and failure mechanism.’