Microtunneling method and device

Abstract

A microtunneling method including placing a boring machine in a starting shaft; jacking the boring machine from the starting shaft along a tunnel towards a target shaft; while electrically rotating a cutter head at a front end of the boring machine about an axis of the tunnel; and pumping a slurry that transports cuttings from the cutter head out of the tunnel, wherein a synchronous reluctance motor rotates the cutter head. To reduce environmental burden, the invention further proposes that electric energy for the boring machine for the jacking and the pumping is buffered.

What is claimed is: 
     
         1 . A microtunneling method, comprising:
 placing a boring machine in a starting shaft of a tunnel;   jacking the boring machine from the starting shaft of the tunnel towards a target shaft of the tunnel; while   electrically rotating a cutter head at a front end of the boring machine about an axis of the boring machine; and   pumping a slurry that transports cuttings from the cutter head out of the tunnel, wherein a synchronous reluctance motor rotates the cutter head.   
     
     
         2 . The microtunneling method according to  claim 1 , wherein electric energy for the boring machine, for the jacking and the pumping is buffered. 
     
     
         3 . The microtunneling method according, to  claim 2 , wherein a power generator providing the electric energy starts automatically when a battery for buffering the electric energy runs low. 
     
     
         4 . The microtunneling method according to  claim 1 , wherein the tunnel is a utility tunnel. 
     
     
         5 . The microtunneling method according to  claim 1 , wherein a voltage of the electric energy is stepped up at the starting shaft and stepped down for the synchronous reluctance motor. 
     
     
         5 . The microtunneling method according to  claim 1 , wherein cans of the boring machine or pipe segments are successively inserted into the tunnel at the starting shaft following the cutter head and jacked towards the target shaft together with the cutter head. 
     
     
         6 . A microtunneling method, comprising:
 placing a boring machine in a starting shaft;   jacking the boring machine from the starting shaft along a tunnel towards a target shaft; while   electrically rotating a cutter head at a front end of the boring machine about an axis of the tunnel; and   pumping a slurry that transports cuttings from the cutter head out of the tunnel.   
     
     
         7 . A microtunneling device, comprising:
 a boring machine including a cylindrical housing, a cutter head arranged at a front end of a can cutter head can, and an electric motor configured to rotate the cutter head about an axis of the cutter head can;   a jacking station adapted to jacking the boring machine from a starting shaft towards a target shaft of a tunnel;   a power generator providing electric energy for the electric motor;   at least one pump configured to pump a slurry that transports cuttings from the cutter head out of the tunnel; and   a control container configure to control the microtunneling device and arranged at a ground surface above the tunnel,   wherein the motor is a synchronous reluctance motor.   
     
     
         8 . The microtunneling device according to  claim 7 , further comprising: a battery configured to store the electric energy. 
     
     
         9 . The microtunneling device according to  claim 7 , further comprising:
 a skid including at least one of the at least one pump,   a power transformer or a frequency converter configures to transform the electric energy for the at least one of the at least one pump.   
     
     
         10 . The microtunneling device according to  claim 7 , wherein the boring machine includes units contained in separate cans.