*Sadatoshi Ohmori¹, Devini Abeyawardena¹, Nobuharu Isago², Susumu Yumiba³ (1. Penta-Ocean Construction Co., Ltd., 2. Tokyo Metropolitan University, 3. Ministry of Land, Infrastructure, Transport and Tourism Kyushu Regional Development Bureau)

*Ryo Kashiwagi¹, Yutaro Goto¹, Yuzi Oosaki² (1. JRTT, 2. PCKK)

*Takeshi Fujita¹, Ko-ichiro Mizuno¹, Ko-zo Abe¹ (1. East Japan Railway Company)

*Koichiro Mizuno¹, Takeshi Fujita¹, Kozo Abe¹, Tsubasa Abe¹ (1. East Japan Railway Company)

*Katsumi Kamemura¹ (1. Fukada Geological Institute)

*Naoto Yoshino¹, Takehiro Kanii¹ (1. Toda Corporation)

*Tatsushi Kajio¹ (1. Ministry of Land, Infrastructure, Transport and Tourism Kyushu Regional Development Bureau Oita Office of River and National Highway)