基于采空区刚度演化的采场围岩稳定性分析OA

In order to investigate the influence of the stiffness of goaf on the stability of surrounding rock in mining area,three numerical models with different goaf stiffness were constructed using PHASE 2D finite element software.ModelⅠhad the highest goaf stiffness,ModelⅡthe lowest,and ModelⅢthe medium.The development of the plastic zone in front of the working face,the vertical displacement of the immediate roof and the overlying strata,and the abutment pressure of the min-ing face were studied.The results showed that:when the mining face advanced 150 m,the widths of the plastic zones in front of the mining face for Models Ⅰ,Ⅱ,and Ⅲ were 2.08 mm,3.56 mm and 3.13 mm,respectively.Hence,the greater goaf stiffness,the smaller plastic zone in front of face.The maximum vertical displacement of the immediate roof were 38.8 mm,106.6 mm,and 96.8 mm,respectively,while the maximum vertical displacement of the overlying strata were 44.85 mm,148.25 mm,and 137.36 mm.As the mining face advanced,the abutment pressure coefficient in front of the face increased first before it is stabilized.The peak values were 2.1,3.7,and 3.4 for Models Ⅰ,Ⅱ,and Ⅲ,respectively.As a result,in-creasing the goaf stiffness is beneficial to improving the stability of the surrounding rock in mining areas.