The model of spatial analogous hyperboloid for three-dimensional rock strata movement in mining engineering

Abstract

Based on a large number of field investigations and the analysis of the "analogous hyperbolic" overall movement model proposed by the author, this paper further extends it to three-dimensional space, and proposes a full-space "analogous hyperboloid"three-dimensional movement model of the mining strata.There are two types of hyperboloids, "quasi-single-leaf"and "quasi-double-leaf", which can approximately describe the three-dimensional movement and surface subsidence characteristics of full-space mining strata under different lithological conditions.The "analogous single leaf hyperboloid" model is a horizontal moving boundary model of the spatial rock layer, which is implicit in the thick loose layer overlying rock; the "analogous double leaf hyperboloid" model is the vertical movement of the spatial surface subsidence and the overlying fissure arch and caving arch.The boundary models are approximately symmetrical with the "origin" in the main key layer, and are embodied in external forms such as surface subsidence under mining disturbance and arch caving of the surrounding rock in the stope. Through theoretical analysis, similar model test and 3DEC numerical simulation, this paper deduces and proves in detail the "analogous hyperboloid" model of spatially mined rock strata movement and surface subsidence under the condition of near-horizontal coal seam mining in thick loose layers.At the same time, this study analyzed the composition conditions, influencing factors and overall migration law of the co-asymptotic conical surface "analogous hyperboloid" model.Results show that under the condition of near-horizontal coal seam mining with thin bedrock and thick loose layer, the "quasi-hyperboloid" theoretical model is in good alignment with the 3DEC simulation results, indicating that the overlying rock migration and surface subsidence in space mining are "analogous hyperboloid" feature.

Keywords

• fracture and movement of overlying strata
• surface subsidence
• analogous hyperboloid
• three-dimensional mobile model
• similarity model test
• three-dimensional distinct element code