Phongsatorn Chanpen
School of Engineering and Technology, Walailak University, Nakhon Si Thammarat
Thailand

Thanongsak Imjai
School of Engineering and Technology, Walailak University, Nakhon Si Thammarat
Thailand

Surin Sutthiprabha
Department of Civil Engineering, Rajamangala University of Technology Tawan-Ok, Bangkok, Uthenthawai Campus
Thailand