EFFECTS OF THE MECHANICAL PARAMETERS OF SURROUNDING ROCK ON SPECIFIC CHISELING WORK AND ATTRITION VALUE OF TBM

This paper explores the effects of rock physical mechanical parameters on the specific chiseling work and attrition value of tunnel boring machine(TBM). It is based on the Zhong Tianshan tunnel of the second line of Nan Jiang railway with TBM. A series of in-situ and laboratory experiments are carried out on the tunnel surrounding rock. The basic mechanical parameters are obtained. They include the longitudinal wave velocity,the uniaxial compressive strength,the uniaxial tensile strength,the static modulus of elasticity,and the cohesive force. Then correlation analysis between the basic mechanical parameters and those of the specific chiseling work and attrition value is carried out using the software SPSS22. The results show that the single factor correlation is weak. On the premise of taking the specific chiseling work and the attrition value as dependent variables respectively and mechanical parameters as the independent variable,we carried out multi-factor regression analysis and polynomial fitting of the data by stepwise method. The results show that the dependent variable is highly correlated with the uniaxial compressive strength and the rock mass integrity coefficient. During the validation of the fitting model,under the condition of uniaxial compressive strength greater than 100 MPa and K_V greater than 0.5,the use of fitting model has a higher accuracy.