Abstract: In order to investigate the zonal disintergration of surrounding rock in deep tunnel, a 3D linear elastic model is built based on linear elastic theory of thick-walled cylinder. The internal wall of model is subjected to decreasing uniform pressure to simulate the processes of cavern static excavation. The end of model is subjected to increasing uniform pressure to simulate the stress concentration effect which causes by cavern static excavation. The external wall of model is subjected to increasing pressure to simulate the stress concentration effect and stress redistribution which caused by cavern static excavation. Based on the elasticity theory and boundary conditions, the stress field, strain field and displacement field around circular opening induced by excavation are determined. We address the following features of the model: tension-compression region, strain gradient, elastic energy of compression and tension from decreasing uniform internal pressure, increasing stress redistribution and increasing uniform external pressure and axial pressure. The results show that the relative change between elastic energy of tension and elastic energy of compression would like to reflect energy release rate and quantity during the processes of cavern static excavation. The stress redistribution and axial pressure are the main factors leading to zonal disintegration. The model provides theoretical basis to study failure of surrounding rock in deep tunnel.

Key words: rock mechanics, thick-walled cylinder, 3D analytical model, deep rock mass, zonal disintegration