关键词: 相似模拟, 围岩蠕变, 循环加卸载, 应变分析, 裂缝发展

Abstract: In order to study the creep effect of roadway excavation in underground rock mass under complex ground stress, the model made of similar materials was loaded and unloaded by a self-developed analog test device. The experimental results show that, after a long period of graded cyclic loading and unloading, the tunnel subsidence occurs at 80% of the compressive strength of the model, and the radius of the tunnel decreases by 1.8%. The strain of surrounding rock exhibits creep characteristics with time, and goes through several stages, such as instantaneous strain, steady strain, hysteretic elastic recovery strain and residual strain. With the increase of load step by step, the strain value and elastic recovery strain both increased, but the increment of strain at each stage gradually decreased, reflecting the transition from elastic deformation to plastic deformation, showing a certain degree of permanent deformation. The trend of volume strain at each point is roughly the same as that of strain variation. Due to the application of load, the original stress state of surrounding rock is changed, resulting in stress concentration, and the creep of surrounding rock is caused by long-term cyclic loading and unloading, which promotes the emergence and expansion of cracks. In addition, the formation and development of cracks further aggravated the deformation of the roadway, resulting in the overall subsidence of the roadway and its shape becoming irregular. This study provides theoretical basis and experimental data support for similar simulation research on stable deformation and failure of deep roadway．