Abstract: The specific wear indexes (SWI, the ratio of cutter wear increase to the rock breaking volume) of every disc cutter are classified and summarized according to stratum boring based on stratumwise summation method. The SWI regression equation, adapting for 4 kinds of homogeneous strata and with boring parameters as independent variable, is achieved. A quantitative prediction method for disc cutter wear based on SWI in composite strata is proposed by combining SWI regression equation and stratumwise summation method of wear. The results show that: 1) The relationship between cutter wear and cutter assembling position and that between cutter wear and tunneling length are taken account simultaneously in SWI, of which the physical significance is explicit. 2) With a fine accuracy of prediction, the SWI regression equation is able to provide alarm value for predicting cutters’ wear limit. The relationship between function coefficients and lithology is discussed; and then the optimal tunneling parameter adjusting methods for minimizing the disc cutter wear in different strata are put forward. The practice shows that the abovementioned disc cutter wear prediction method is of highprecision.

Key words: composite strata, shield tunneling, disc cutter wear, specific wear index (SWI), stratumwise summation method