Ph.D. Student, Research Institute of Civil Engineering and Mechanics, Centre National de la Recherche Scientifique, Université de Nantes, 58 rue Michel Ange, BP 420, Saint-Nazaire Cedex F-44606, France; Associate Professor, Faculty of Bridge and Road Engineering, Univ. of Science and Technology—Univ. of Danang, 54 Nguyen Luong Bang St., Lien Chieu District, Da Nang City, Vietnam. (At 2018-09)