Force transmission characteristics for the non-equidistant arrangement thrust systems of shield tunneling machines

Earth Pressure Balance shield tunneling has been successfully adopted for urban tunneling and has resulted in increases in working speed, savings of man-hours and improved safety. Based on the ellipse eccentricity, the ellipse matrix equation for non-equidistant systems has been constructed. Through the analysis of the matrix, the characteristics of force ellipse eccentricity were investigated in detail. The distinction from the equidistant system was studied by applying the force ellipse to the thrust systems of shield machines in engineering applications. It provides a new arrangement for the thrust system hydraulic cylinders, under large change-of-direction forces or uneven geological bodies, which may prevent the segments from cracking due to an over-offset load.