发明名称 |
Center-cut method for tunnel excavation utilizing large unloaded blast holes and a circular pre-split |
摘要 |
Disclosed herein is a center-cut blasting method for tunnel excavation. The center-cut blasting method includes the step of drilling a single central center-cut hole at the center of a center-cut region, drilling a plurality of auxiliary center-cut holes comprised of large unloaded auxiliary holes and loaded auxiliary holes that are alternately arranged around the central center-cut hole to be situated in a circle having a predetermined diameter, and drilling a plurality of spreader center-cut holes outside the auxiliary center-cut holes to be situated in concentric circles centered by the central center-cut hole. Thereafter, the center-cut holes are loaded with delay detonators and explosives and the center-cut holes are stemmed with stemming material at their entrances. The loaded auxiliary holes of the auxiliary center-cut holes are blasted so as to create a circular pre-split. After that, the central center-cut hole is blasted so as to create initial dual free surfaces. The spreader center-cut holes are sequentially blasted with a time delay so as to create final dual free surfaces.
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申请公布号 |
US6431075(B2) |
申请公布日期 |
2002.08.13 |
申请号 |
US20000750842 |
申请日期 |
2000.12.28 |
申请人 |
SHIM DONG SOO;MOOJIN NEOTECH CO., LTD. |
发明人 |
SHIM DONG SOO;LIM HAN UK;CHO YOUNG DONG |
分类号 |
F42D1/00;(IPC1-7):F42D3/00 |
主分类号 |
F42D1/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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