The shield driving parameters are closely related to geological conditions

and its calculation and surface deformation pattern in thick alluvial loess-clay have significantly regional characteristics which vary greatly from place to place.The setting range of shield driving parameters and its modified formulas were determined through statistical analysis of the field measured data of 6.68 m-diameter shield tunnels in the Jinan rail transit line R1.The correlation between driving parameters and its influence law on surface deformation were explored.The results demonstrate that the correction coefficient of theoretical calculation for thrust force

cutterhead torque

and chamber earth pressure ar

e 0.677

0

.753

0.882

1

.260

0.985

1

.641

respectively.The synchronous grouting amount and excavated earth amount present strong linear correlations with the shield driving speed.The shield driving parameters have significant effects on surface deformation.The maximum ground settlement and ground loss ratio increase with the decrease of chamber earth pressure.Both of the maximum ground settlement and ground loss ratio decrease as a quadratic function of driving speed

and decrease linearly with the increase of synchronous grouting rate.