Abstract: To provide basis for the stability assessment and protection work design of Pilu Cave,high density electrical technique was applied to the geophysical prospecting of rock fracture and landslide disaster in the grotto.The effects of fracture development,engineering and hydrologic and geologic conditions on the deformation of grotto and ground surface were explored.Results indicated that rock fractures in the Liubenzhen Sculptures Grotto and Thousand Buddha Cave are well developed,and will develop further under the action of surface water erosion and plant’s root growth, posing severe adverse impact on the stability of the cave. Connected groundwater and vertically-developed water-bearing fracture zone are main factors affecting the stability of landslide, and the water-bearing fracture zone together with the weak contact zone of different rocks forms the attachment surface of the landslide’s back edge, which is unfavorable for the slope stability.

Key words: high-density electrical method, grotto, conservation work, geological survey