Research on Strata Deformation Induced by EPB Tunneling in Round Gravel Stratum and Its Control Technology

Recently, many studies have been conducted on the stratum deformation induced by earth pressure balance (EPB) shield tunneling in soft soil and sand. Movement laws vary largely among different strata. However, at present, relevant research mainly focuses sand, whereas little attention has paid to movement law of round gravel with higher instability. In this study, a field monitoring test was carried out EPB machine when it passes through stratum. Based analysis results under chamber pressures, thrust force, torque cutter, grouting pressure, volume, relationships between parameters their influence disturbance surrounding mass were investigated. It found that surface shape section south north lines conforms Gaussian curve. The vertical tunnel axis is largest. maximum value observed cutter head reaches section. horizontal stage tail pass strata not only related properties but also strong positive correlation parameters. main factor affecting before arrival head, volume during