ABSTRACT
Yang et al. (2010) and Li et al. (2010) deeply studied the weathering law and the stress state of the surrounding rock by means of the direct-viewing analysis of integrity characteristics for underground cavities, which were filled with water and not filled with water. They indicated that it is the key factors to the long-term stability of ancient underground cavern group that the caverns in Longyou are filled with water. Li et al. (2005) carried out the cause analysis of cavern roof falling off, sidewall collapsing and rock pillar cracking, as well as the weathering phenomenon induced by dry-wet alternating change of the surrounding rock in the Longyou Grottoes from the perspective of engineering
1 INTRODUCTION
The part caverns in the Longyou Grottoes (i.e. Phoenix Mountain ancient underground cavities) are closely related to underground water and groundwater environment, in which some still have encountered the hydraulic unloading and loading processes again due to pumping and filling water. In order to discuss the hydraulic and water environment influence on grotto caverns, many researchers carried out further study in the weathering and the stability of the surrounding rock of caverns under different filling water, anhydrous state and different water environments (Yang et al. 2010).
