1. Faculty of Engineering China University of Geosciences (Wuhan) Wuhan 430074 China
2. Department of Scientific Protection and Research Shaanxi Institute for the Preservation of Cultural Heritage Xi'an 710075 China
3. Institute of Conservation and Restoration Chinese Academy of Cultural Heritage Beijing 100029 China
4. Department of Protection Research Institution of Dazu Rock Carvings Chongqing 402360 China