Numerical simulation on coupling method between mining-induced stress and goaf compression

The goaf stress recovery under the effect of overlying strata subsidence has notable effect on mining-induced stress field. Based on the coupling effect between ground stress and goaf compression,the mechanical characteristics and properties back-analysis method of caved rock are studied,the tension-weakening characteristics of rock mass in fractured zone are analyzed,and hereby the coupling simulation method between mining-induced stress and goaf com- pression is proposed and verified using a simulation case study. The results show that the mechanical behavior of the compressed caved zone follows an exponential growth,the compression stiffness nonlinearly increases with the compres- sion strain. The mechanical properties of caved zone obtained from back-analysis agree with the analytical results, which contribute to the simulation of the mechanical behavior of goaf. The tension-weakening model,which is developed from strain-softening model by adding the tension-weakening algorithm,can describe the weakening of Young’ s modulus,hereby achieve to describe the mechanical behavior of fractured rock mass rigorously. Based on the mechani- cal behavior simulation of caved and fractured zone,the proposed method can conduct the coupling numerical simula- tion of mining-induced stress field and the overlying “two-zone”.