1. Assistant Professor, Dept. of Civil Engineering, Gumushane Faculty of Engineering, Karadeniz Technical Univ., 29000 Gumushane, Turkey. E-mail: yetgins@hotmail.com
2. Research Assistant, Dept. of Civil Engineering, Gumushane Faculty of Engineering, Karadeniz Technical Univ., 29000 Gumushane, Turkey. E-mail: ahmcavdar@hotmail.com