Shield Tunneling Parameters Control in Medium-Strong Weathered Muddy Siltstone Composite Stratum

Shield tunneling parameters are an important factor affecting construction safety and construction efficiency during shield tunnel construction. Based on the three-dimensional particle flow discrete element method, a numerical model of rock breaking by full cutterhead cutter in composite stratum was established. By analyzing the rock-breaking force of the cutterhead under different tunneling parameters of the shield, the relationship between the maximum tunneling speed of the shield and the rotating speed of the cutterhead was determined, and the division range of the shield tunneling parameter control zone in the medium-strength weathered argillaceous siltstone composite formation was proposed. The values of shield tunneling parameters can be divided into three areas: maximum penetration speed control area, rock-breaking force control area and shield design parameters control area. In the maximum penetration speed control area: cutterhead rotating speed 0 < w < 0.05, maximum tunneling speed 0 < v < 175w; in the rock breaking force control area: cutterhead rotating speed 0.05 < w < 1.55, maximum tunneling speed 0<v<-8.527w²+61.058 w+5.945; in shield design parameters control area: cutterhead rotating speed 1.55<w<3, maximum tunneling speed 0<v<80.