Safety of unshielded tunnel boring machines and rodless shaft boring machines for rock - Safety requirements
|Publication Date:||20 October 2008|
|ICS Code (Tunnel construction):||93.060|
1.1 Field of application This standard is applicable to unshieldsed tunnel boring machines, TBM's, and rodless shaft boring machines, SBM's, and their towed or attached back-up equipment for driving tunnels or shafts in rock where the whole area is excavated in one or more steps by mechanical means. It specifies essential safety requirements for the design, construction and maintenance of such machines when used in non-explosive atmosphere together with the methods of verification. The standard specifies monitoring for hazardous atmosphere. For TBM's and SBM's which are to be used continuously in explosive atmosphere, additional relevant standards also apply. This European Standard deals with all significant hazards pertinent to unshielded tunnel boring machines and rodless shaft boring machines for rock, when they are used as intended and under the conditions foreseen by the manufacturer (see clause 4). This European Standard specifies the appropriate technical measures to eliminate or reduce risks arising from the significant hazards. 1.2 Description of the machines The general term ""unshielded tunnel boring machines"" encompasses various kinds of machines for mechanical excavation of underground openings such as tunnels and inclined shafts. This is done in a continuous process, without blasting, using a rotating cutter head. Depending on the hardness of the material being excavated, tools of different types are used to cut the rock. Normally, rolling discs are employed in medium to very hard rock. All tunnel boring machines, TBM's, and rodless shaft boring machines, SBM's, have the tools mounted on a cutter head which rotates under thrust against the rock. The torque required to rotate the cutter head is developed by electric or hydraulic motors and the thrust is normally delivered by hydraulically powered cylinders. The torque and thrust reactions created by a TBM or SBM have to be resisted by anchoring the complete machine inside the bore itself by ...