Abstract
Caving mining is widely used for deep ore extraction because of its high productivity and cost efficiency. However, accurately predicting the three-dimensional (3D) caving morphology and collapse height remains challenging for safe mine design. Classical arch theories are limited to 2D plane-strain conditions, while conventional numerical methods are either computationally expensive or unable to capture the progressive nature of 3D rock caving. In this study, a 3D continuum-based numerical framework is developed to simulate rock caving by defining tension-induced detachment of plasticized rock mass as the primary failure mechanism. Progressive collapse is represented through an iterative element-removal scheme implemented in FLAC3D. The proposed method is first verified against classical caving arch theories for different undercut spans, showing good agreement with the self-stable arch theory. It is then applied to the 37-2# orebody of the Anhui Taiping Mine to simulate the evolution of the caving zone and quantify its height, volume, and spatial morphology during staged mining. The results show that the caving zone expands upward progressively and develops an arch-like geometry in cross-section. Sensitivity analyses indicate that the internal friction angle has the strongest influence on caving height and volume, as it controls shear resistance, stress arching, and tensile stress redistribution at the caving boundary. The proposed approach provides an efficient and mechanically interpretable tool for evaluating caving behavior and supporting risk assessment and backfill design in underground mining.