Evaluation of the effect of rolling correction of double-o-tunnel shields via one-side loading

During construction of a double-o-tunnel (DOT), rolling will inevitably occur due to the following: (i) nonuniformity of subsoil condition, (ii) manufacturing errors in the DOT shield machine, (iii) different pulling forces at two sides of the DOT, (iv) effect of assembled segments, (v) loss of grout, and (vi) inappropriate operation. In engineering practice, rolling correction using a one-side load at the elevated side is a cost-effective method. The weight of the one-side load is determined by the experience of the engineers and (or) through observation of the returned rolling angle. However, these methods cannot predict the value of the one-side load before applying it. This paper presents a series of finite element analyses that was performed to investigate the relationship among the one-side load, rolling angle, and subsoil deformation. The analytical results show that the proposed approach can predict field-observed data well. It is concluded that analytical results can be used as guidance for DOT construction.