Abstract The mechanical pre- cutting method is a predominant method for tunnels in soft rock, by which the formed pre-lining can effectively control stress release and stress redistribution, significantly reduce the height of the load-carrying arch and thus control deformation of the rock mass. However, pre-cutting technology has some difficulties regarding completing troughs, water sealing and mass equipment handling. A new thought for the development of a pre-cutting machine is proposed based on the above and the first generation of a linear drilling-type precutting machine is developed. Trough cutting and concrete pouring are carried out under the protection of a driving box, with little trough deformation and a uniform texture of the concrete arch shell. Industrial tests shows that this new type of machine can truly realize the original intention of pre-cutting technology and possesses unique advan? tages.
Abstract：
The mechanical pre- cutting method is a predominant method for tunnels in soft rock, by which the formed pre-lining can effectively control stress release and stress redistribution, significantly reduce the height of the load-carrying arch and thus control deformation of the rock mass. However, pre-cutting technology has some difficulties regarding completing troughs, water sealing and mass equipment handling. A new thought for the development of a pre-cutting machine is proposed based on the above and the first generation of a linear drilling-type precutting machine is developed. Trough cutting and concrete pouring are carried out under the protection of a driving box, with little trough deformation and a uniform texture of the concrete arch shell. Industrial tests shows that this new type of machine can truly realize the original intention of pre-cutting technology and possesses unique advan? tages.
2017, Vol. 54 