Stability Study of the Roof Plate of the Yuanjue Cave Based on the Equivalent Support Stiffness Method

As precious cultural heritage sites, the state of preservation of cave temples is closely related to the geological and climatic conditions in which they are located. This paper constructed an analytical method of sized slate stability based on the equivalent support stiffness method. The stability analysis of the roof slab of Yuanjue Cave was carried out by establishing a three-dimensional numerical calculation model. Through comparative analysis of the results of stress and displacement fields under different conditions, the stress and deformation characteristics of the roof slab of Yuanjue Cave were revealed, as well as the study of the main factors affecting the stability of the roof slab of Yuanjue Cave and the key slate to be monitored. The main research results are as follows. The stress deformation of the roof plate of Yuanjue cave is mainly divided into the initial uniform change stage, the medium-term stable change stage or the medium-term accelerated change stage, and the later rapid change stage. With the increase in the number of overhanging and broken slates and the increase in the damage factor of cracked slates, the vertical stress extremum of the stones increases continuously, and the equivalent support stiffness decreases, which aggravates the uneven stress deformation of the roof of the Yuanjue Cave. This study provides a reliable reference basis for the stability analysis and evaluation of the roof slab of a large number of cave temples existing in the Sichuan and Chongqing areas in China.