Evaluation of the Arching Effect in Cavity with Various Initial Shapes Based on Principal Stress Vector Field

Abstract

The arching effect arises during the formation and development of underground cavities and is closely associated with the final collapse of sinkholes. When the arching effect can no longer sustain the weight of the overburden soil or move upward to the surface, where the conditions prevent its further formation, cavity collapse occurs. Therefore, identifying the top boundary of the arching effect, discerning its shape and size, and tracking its evolution throughout the sinkhole formation and development process are critical and highly anticipated tasks. This paper proposes a method for identifying the position of the arching effect in finite element analysis based on singular points where the magnitudes of principal stresses are equal within the principal stress vector field. Concurrently, the arching effect surface is visualized using the principal stress vector field and applied to several cavities with different initial shapes. The characteristics and differences in the arching effect surfaces are analyzed and compared. Results show that varying initial cavity shapes lead to different positions and forms of the arching effect, providing new insights into the study of arching effects in sinkholes.