A comprehensive stability evaluation method integrating similarity analysis, numerical simulation, and theoretical analysis and its application in Cave 32, the North Grotto Temple, China

Abstract

The grotto temples are rock-cut architecture originally constructed for religious purposes. These caves, carved in cliffs, have been eroded by natural forces and destroyed by human activities over an extended period. Accurate stability assessment serves as the foundation for the preventive protection of the caves. However, an integrated evaluation system has not been developed to date due to diverse variations in the mechanisms of disease formation, influencing factors, material properties, and structural characteristics. In this paper, we proposed a comprehensive stability assessment method for grottoes, integrating similarity analysis, numerical simulation, and theoretical analysis. The methodology comprises four key steps: (i) We collected essential attribute parameters related to grotto stability from representative grottoes in China to establish a database. Through similarity calculation of these control parameters between the research object and database, a distance discrimination model incorporating expert experience was trained for the cave's initial and rapid stability grading; (ii) Establishment of a refined 3D numerical model of the cave based on point cloud data obtained through laser scanners and UAV, and numerical analysis to determine the stress and displacement distribution and identify potential failure zones; (iii) the Limit Equilibrium Method (LEM) further was employed for quantitative calculations of stability factor of vulnerable zones revealed by numerical modeling; (iv) Methodology comparison and discussion to obtain the comprehensive results. The established procedure has been successfully applied in Cave 32 of the North Grotto Temple in China, which demonstrates its potential as a pioneering framework for the precise evaluation of similar cases, contributing to the preservation of stone cultural relics.