Unifying the extension theory and evaluation methods of tunnel surrounding rock masses stability

the surrounding rock masses stability types are determined synthetically by selecting some synthetical characteristic parameters that can reflect the stability of surrounding rock masses on the basis of the geological documentation of muck and the boring parameters of the tunnel boring machine （TBM） during the tunnel construction of double-shield TBM. The concept of membership degree and one kind of method that can determinate the selected patameters weight introducted

the extension evaluation method of tunnel surrounding rock masses stability classification is set up based on the operation of matter-element theory

extension set and dependent function. The surrounding rock masses stability classification of two sections of tunnels is carried on by applying the method based on the extension theory during the construction of double-shield TBM in the Yellow River Diversion Project of Shanxi province; and the rational result is in conformity with the reality.