| 摘要 |
The subject matter of the invention is a device for drilling two galleries facing each other and extending on either side of a pipe (5), which comprises a thrust assembly (10) provided with two mobile thrust plates (11a, 11b) for axial thrust from a first and a second side of the thrust assembly, a support frame (15) for the thrust assembly and sliding tubes, two drilling heads (12a, 12b) and sliding support tubes (13a, 13b) positioned between the mobile thrust plates (11a, 11b) of the thrust assembly and the drilling heads (12a, 12b). The invention further concerns a method for drilling galleries from a pipe using a micro tunnel-boring machine which comprises a step of simultaneously digging two galleries along the same axis and in opposite directions while balancing the thrust forces of the micro tunnel-boring machine on each side so as to limit the stresses on the pipe to the difference between the thrust forces on each side. |
