1. School of Civil and Resource Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, P. R. China
2. XCMG Construction Machinery Co. Ltd., Dahuangshan Road, Gulou District, Xuzhou, Jiangsu 221004, P. R. China
3. Tangshan Jidong Equipment and Engineering Co., Ltd., Qiancao Road, Caofeidian District, Tangshan, Heibei 063200, P. R. China