Aiming at the disadvantages of rockburst proneness criterion in application of tunnel boring machine(TBM) tunnel construction stage

a novel rockburst predictive method applying to tunnel construction stage is proposed

considering the key influence factors of rockburst such as the in-situ stress

the rockmass integrality

the rock strength and construction disturbance during tunnel construction. Firstly

the uniaxial rockmass strength based on Hoek-Brown strength criterion is estimated

by introducing five parametric attributes of rock strength

brittleness coefficient

the quantitative geological strength index (GSI)

the excavation disturbance factor D and the maximum in-situ stress .Then

a novel rockburst predictive index is put forward by the strength-stress ratio method of engineering rockmass; and the corresponding threshold values of the new index are presented. Case studies for application further verified the feasibility and reliability of the novel index

so as to provide a practical method for the study of rockburst prediction.