Abstract:

The rock is simulated by JHC constitutive model, the rock broken by shield cutter group under different modes are numerically stimulated by dynamic analysis software LSDYNA; and then the timedependent threedimensional load and load spectrogram of disc cutter and cutterhead of shield are derived by mechanical analysis of disc cutter and cutterhead and Fourier transform, by taking Su’ai shield tunnel and cutterhead of TBM under modal system for examples. The analytical results show that: 1) The loads of disc cutter and the cutterhead show mutagenicity，randomness and impact during rock breaking; the load of disc cutter varies suddenly and the disc cutter vibrates seriously when the disc cutter cutting the interface of hard rock and soft rock. 2) The loading frequency of the cutterhead, 0-5 Hz and belongs to low frequency, coincides with that of disc cutter; the soft rock and hard rock only affect the amplitude of disc cutter load, and affect the distribution of the frequency little. Furthermore, the positions of maximum stress and strain of cutterhead under heterogeneous stress condition are determined by statics analysis of cutterhead in heterogeneous strata. The results can provide reference for cutterhead test system of physical modeling experiment of rock broken by disc cutter of Su’ai Tunnel.

Key words: composite strata, shield, model test, load on cutterhead, cutterhead vibration, LSDYNA