关键词: 损伤本构模型, 随机性, 陷落柱, 数值模拟

Abstract: The key to predicting the water inrush or not from karst collapsed column is to accurately describe mechanical properties and damage depth of rock under the mining influence. A modified parallel rod model is established based on the dissipative structure theory, and the damage evolution equation is obtained according to the data of acoustic emission (AE) and stress-strain curve. By combining Drucker-Prager (D-P) yield criterion with the corresponding non-association flow law, the D-P elastic-plastic double scalar stochastic damage constitutive model was established. The damage law of WDX40 karst collapse column in 51510 working face of Chengzhuang coal mine is studied by the newly established constitutive model. The main conclusions are as follows. Rock material can be regarded as a structure which has the characteristic of non-uniform energy dissipation, showing the "elastic modulus degradation" under cyclic loading. The D-P stochastic damage model can well reflect the "nonlinear" and "random" characteristics of rock, and the rationality of the stress-strain curve is calculated in the probability sense. The depth of compressive damage in the karst collapsed column shows an asymmetric inverted saddle-shaped distribution, and the depth in the side-wall away from the starting cut is the largest, which is 1.75 times the depth of complete floor

Key words: constitutive model, randomness, karst collapse column, numerical simulation