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Abstract Considering the deterioration effect on rock mass parameters caused by construction disturbance，the disturbance factor D is proposed in the Hoek-Brown empirical criterion(2002 edition)，but it is only a rough qualitative description. The wave velocity drop l obtained from sonic wave testing is employed to optimize the disturbance factor D；and the optimized Hoek-Brown empirical criterion can be used to get the solution to the characteristic formula of rock mass elastoplastic deformation caused by excavation disturbance. Thus，the radius of plastic ring can be represented more accurately. In order to verify the rationality of that theory，various monitoring methods，such as sonic wave testing and displacement monitoring methods，etc.，have been applied and the finite element numerical simulation method is used to compare with the monitoring methods as well. In addition，taking into account the site effect of deformation characteristics induced by excavation disturbance，an empirical formula of deformation and excavation disturbance fitted with different lithologies and excavation methods is put forward. The calculation results of an engineering example indicate that the optimization of disturbance factor D from the Hoek-Brown empirical criterion(2002 edition) is reasonable；and it can calculate the eigenvalue of rock mass elastoplastic deformation caused by excavation disturbance and accurately obtain the radius of plastic ring. Furthermore，the empirical formula of deformation and excavation disturbance obtained by fitting can satisfy different engineering demands with certain rationality. This study can provide a methodological reference for researching the Hoek-Brown empirical criterion and the characteristics of rock mass elastoplastic deformation caused by excavation disturbance in underground caverns.
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Received: 25 February 2010
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