Abstract:The basic principle and general scheme of disc cutters layout of shield machines were summarized, and a method of solution for general double spirals coefficients were proposed according to the optimal cutter distance and adjacent cutter phase-difference. Consequently, a different layout pattern in double spirals was provided and discussed in detail with the Shiziyang shield tunneling engineering as the case of application. Moreover, the sequence and efficiency of rock-breaking when the cutter head rotating normally and reversely were analyzed. Analysis of the statistical data of the Shiziyang tunnel construction shows that there exists a significant local wearing at the crossing of two spirals. The shield cutter layout in reverse cross double spirals pattern can raise the rock-broken efficiency when the cutter head rotating reversely, but the cutters will be worn out quickly and unevenly.