Abstract：Rockburst is a kind of dynamic instability phenomenon of surrounding rock in underground projects in deep high-geostress zone. The prediction of possibility and classification of rockburst are basic issues in many underground projects. Based on the fuzzy probability theory，a new fuzzy probability model is established to predict rockburst occurrence and its intensity. Some main control factors of rockburst，such as the maximum tangential stress of the cavern wall ，the uniaxial compressive strength and the uniaxial tensile strength of rock，the elastic energy index of rock，are chosen in the analysis. Three factors including ， and are regarded as the evaluating indices. And rockburst intensity is classified as the non-rockburst，slight rockburst，medium rockburst and serious rockburst in the prediction model. In order to assess the index weight scientifically and to avoid the uncertainties while determining the index weight，the fuzzy weight is introduced into the rockburst prediction model. The fuzzy probability model not only holds the merits of classical fuzzy comprehensive evaluation method，but also overcomes its limitations in practice. Rockburst predictions of Dongguashan deep hard rock mine，Qinling Tunnel and an underground hydropower station are performed by this model. Furthermore，23 underground rock projects at home and abroad are also evaluated with the proposed method. The prediction results agree well with the practical records. It shows that the fuzzy probability model is reasonable and effective to predict the possibility and classification of rockburst in deep underground engineering.
