| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a tunnel excavation device for renewing an existing duct, capable of efficiently excavating a ground on the outer periphery of the existing duct and scraping a hardened layer of back-filling agent or the like fixed to the outer peripheral face of the existing duct when renewing the existing duct such as a deteriorating sewer into a new duct. <P>SOLUTION: While a cutter bit mounted at the front end of an outer cylinder 3 so as to propel inner and outer cylinders 3, 6 covering the rear end of the existing duct P1 to the front side of a shield body 1 integrally with the shield body 1 excavates a ground on the outer periphery of the existing duct P1, a scraping blade 9 mounted at the front end of the inner cylinder 6 and a jet water injection nozzle 10 scrape the back-filling agent hardened layer on the outer peripheral face of the existing duct P1. The inner and outer cylinders 3, 6 are vertically and horizontally flexible relative to the shield body 1 for accurate excavation along the flexuous outer peripheral faces of a snaking part and a curving construction part when existing in the existing duct P1. <P>COPYRIGHT: (C)2012,JPO&INPIT |
