Abstract: In order to study the quantitative relationship between shield tunneling parameters in composite strata on the particle characteristics of muck, the experimental study and statistical analysis are conducted. Firstly, the muck sample particles are collected in field shield tunneling test under different effective thrust forces and rotation speeds of cutterhead. And then the statistical analysis of particle screening results is carried out, and the prediction equation of particle grading of muck is proposed. Finally, the multiple regression prediction and influence analysis are carried out for the coefficients of the grading prediction equation, and the correlation between the coefficients of the equation and the tunneling parameters is quantitatively studied. The results show that: (1) When the rotation speed of cutterhead or effective thrust force of shield increases, the characteristic particle size of muck sample decreases, the coarse particle 〖HJ2.7mm〗content in muck decreases, the fine particle content increases, and the particle size distribution range of muck sample widens. (2) The particle size of muck particles has an upper limit, and RosinRammler distribution function is more suitable for analyzing the grading characteristics of shield broken rock particles. (3) Within a certain range of tunneling parameters, the prediction model of particle grading equation coefficients of shield muck is more accurate, which can better reflect the influence of tunneling parameters on the equation coefficients in engineering practice.

Key words: shield, composite strata, tunneling parameters, muck, particle characteristic, gradation curve equation