*Kiyonobu Kasama¹, Zentaro Furukawa¹, Yuichi Yahiro¹, Takahiro Sato², Hikaru Mouri², Hiroaki Nakayama³, Hidekazu Matsubara⁴, Shinichi Tsukamoto⁵ (1. Kyushu University, 2. Kumamoto University, 3. The Japan Iron and Steel Federation, 4. Japanese Association for Steel Pipe Piles, 5. OYO Corporation)

*Tomoya Ito¹, Taketo Hayashi¹, Takeharu Konami¹ (1. OKASANLIVIC.CO.,LTD.)

*Yujin Suda¹, Hiroto Koide¹, Toshikazu Sawamatsu¹, Toshiaki Mabuchi¹ (1. Public Works Research Institute)

*Tianle Xue¹, Takeshi Ishiguro¹, Tuyoshi Kameda¹, Hiroshi Yamanokuchi¹, Yuji Hayashi¹ (1. MAEDA CORPORATION)

*Mikio Kubo¹, Masaaki Yokoyama¹, Jun Harada¹, AUNG HLAHLA¹, Tomoyuki Obata¹ (1. JSCE)

*Ryutaro Tamura¹, Ryunosuke Kido², Yasuo Sawamura², Makoto Kimura² (1. Ministry of Land, Infrastructure, Transport and Tourism, 2. Kyoto University Graduate School)