The Research On Tuff Wear Resistance Of Daiyun Mountain Tunnel In The Railway Xiangtang To Putian

In the process of tunnel construction by TBM, the hob which contacts the tunnel face directly is the main wear part, so it is necessary to study the correlation of rock wear resistance. Through rock experiment, analyze the relationship between index of wear resistance and other index, and combine the theory to explain their correlation.Firstly, analyze the mechanism of hob breaking rock and rock abrasion. Analysis illustrate that hob in the cutter head works as three dimensional movement which forward along the central axis of cutter head, spin along the central axis of cutter heard and rotation. It squeezes and rolls rock based on the propulsion and rolling force from power system, propulsion should be more than rock compressive strength, rolling force should be more than rock tensile strength or shear strength. The interaction between rock and hob, hob wears with adhesive wear, abrasive wear and surface fatigue.Then, experiment research on the18groups of tuff rock samples, including abrasion test, basic physical properties test, mechanical properties test and rock identification. The basic physical properties test involves dry density, water absorption, and acoustic velocity; mechanical properties test involves uniaxial compression strength and deformation, uniaxial tensile strength, and triaxial compression; rock identification involves rock hand specimens observation, rock thin section identification.Finally, fit the correlation between index of wear resistance and other experiment index by the Origin software, select the highest determination coefficient as the optimal fitting standard, and analyze the correlation based on theory. Research illustrates that the wear resistance of tuff has significant correlation with dry density, acoustic velocity, elastic modulus, passion ratio, uniaxial compression strength, uniaxial tensile strength and the C,φ under triaxial peak strength; the wear resistance of tuff has low correlation with unconfined residual strength, its correlation need further research; the mineral component of tuff has a significant influence on its wear resistance, especially in quantity, particle size and arrangement of mineral component; the structure of tuff mineral component also a significant influence on its wear resistance, vitric tuff’s index of wear resistance is higher than crystal tuff, lithic tuff has the lowest index of wear resistance. The index of wear resistance of tuff is a comprehensive index, it is affected by basic physical properties, mechanical properties and its mineral component structure.