It is difficult to estimate the detailed rock strength of excavating face timely and effectively when tunnel boring machine(TBM) advances

which results in it difficult to predict the risk of rockburst and TBM jamming. Based on previous research results and engineering practices

a method for estimating rock strength using TBM parameters is proposed for real-time in-situ estimation of rock strength. The equation of real-time estimation is established by the mechanical analysis between TBM specifications

excavation parameters and the rock strength. Then the relationships between the constants in the equations and the TBM specifications such as excavation(tunnel) diameter

cutter diameter are determined in this study on the basis of data collected at several tunnels. Typical TBM case studies for application further verified the wide suitability and reliability of the novel equations. The proposed method appears to be promising and feasible for real-time in-situ estimation of rock strength.