为探究超临界CO₂注入废弃采空区引起的地表形变特征，利用FLAC^3D模拟研究了地表形变一般特征与演变过程，并从形变范围、形变量等5个方面探讨了孔隙率、CO₂注入速率和封存深度对地表形变特征的影响。结果表明：CO₂注入废弃采空区后引起的地表形变呈“倒碗”形隆起形态，并经历孕育阶段、活跃阶段和稳定阶段的演变过程；随着地表点远离采空区，其在孕育阶段和稳定阶段的位移量占比逐渐增大；地表变形范围随着CO₂封存深度的增加明显减小，受孔隙率和CO₂注入速率变化影响较小；地表位移量随着孔隙率和CO₂封存深度的增大而逐渐减小，受CO₂注入速率变化影响较小；地表形变持续时间与孔隙率和CO₂注入速率正相关，与CO₂封存深度负相关；地表点在孕育阶段和稳定阶段的位移量占比与所需时步数与孔隙率和封存深度正相关，与CO₂注入速率负相关。

In order to explore the characteristics of surface deformation caused by supercritical CO₂ injection into abandoned goaf, the general characteristics and evolution process of surface deformation were studied by FLAC^3D simulation. The effects of porosity, CO₂ injection rate and storage depth on surface deformation characteristics were discussed from five aspects, such as deformation range and deformation amount. The results show that the surface deformation caused by CO₂ injection into the abandoned goaf is in the form of “inverted bowl” uplift, and experiences the evolution process of incubation stage, active stage and stable stage. As the surface point is far away from the goaf, the proportion of its displacement in the incubation stage and the stable stage gradually increases. The surface deformation range decreases significantly with the increase of CO₂ storage depth, and is less affected by the change of porosity and CO₂ injection rate. The surface displacement gradually decreases with the increase of porosity and CO₂ storage depth, and is less affected by the change of CO₂ injection rate. The duration of surface deformation is positively correlated with porosity and CO₂ injection rate, and negatively correlated with CO₂ storage depth. The proportion of the displacement of the surface point in the incubation stage and the stable stage is positively correlated with the number of time steps required and the porosity and storage depth, and negatively correlated with the CO₂ injection rate.