Abstract: During double-o-tube DOT tunnel construction, rolling will inevitably occur due to the following reasons: different subsoil condition; manufacturing errors of machine; different pull forces at the two sides; effect of assembled segments; loss of grouts; and operation problems. Several countermeasures to correct rolling have been proposed. Loading using lead block at the elevated side is the most easy and economic method. In engineering practice, the weight of loading is determined by the experience of operating workers and/or through the observation of returned rolling angle. There is no prediction method before loading applying. Moreover, loading correction will also cause additional movement of surrounding ground. This paper analyzes the weight-correcting angle relation and deformation around DOT shield by employing FEM. For the allowable angle of 0.6 degree, the applied load should be 350 kN. Correcting 0.6 degree causes about 85 mm of additional surface settlement. These results can give a guide to the construction management.

Key words: DOT shield, rolling, single side loading, effect of loading, finite element method, settlement