Funding for this research was provided by:
National Natural Science Foundation of China (41472329)
Chengdu University of Technology (SKLGP2017K022)
Institute of Rock and Soil Mechanics, Chinese Academy of Sciences (Z016009)
Guangxi Natural Science Foundation (2016GXNSFGA380008)
Innovation Project of Guangxi Graduate Education (YCBZ2018025)
Article History
Received: 8 November 2018
Accepted: 17 July 2019
First Online: 22 July 2019