1. 1) Japan Institute of Construction Engineering (2002): Manual of Structure Investigation of River Levees (in Japanese).
2. 2) Japan Institute of Construction Engineering (2012): Manual of Structure Investigation of River Levees (revised edition) (in Japanese).
3. 3) Kodaka, T., Itabashi, K., Nakasima, K., Makita, Y., Lee, K.-T., Uemura, T., Tsubota, K. and Kato, M. (2010): Evaluation of deformation and strength characteristics of sandy gravel in river embankments, Japanese Geotechnical Journal, 5(2), 193-205 (in Japanese).
4. 4) Kodaka, T., Cui, Y., Lee, K.-T., Kanematsu, Y. and Kobyashi, Y. (2013): Effects of test conditions of triaxial test on the strength coefficients of river soils, Advances in river engineering, 19, 81-87 (in Japanese).