The study of rock burst position and failure mechanism along the axial direction can provide basic information for the prediction and precaution of rock burst in deep tunnel.The beam-column mechanical model was established based on structure

stress and deformation features of the surrounding rock in deep tunnel.By using the elastic theory and force method

the deflection and slope equations for the first order statically indeterminate beam-column were derived

and the analytical expression for critical force calculation was presented.On the basis of the measured data of the excavation disturbed zone（EDZ）in the tunnel of JinPing II hydropower station

the method for section size determination in beam-column model was provided.The critical lengths

beyond which the stability issue must be taken into account

and the characteristic lengths

at which the critical state of stability is reached

for the surrounding rock were calculated.Finally

a conceptual model representing the evolution process of rock burst in deep tunnel was put forward.And the influences of excavation and dynamic disturbance on the initiation and propagation of internal cracks

structure form of surrounding rock and failure mode of rock burst during construction were discussed.