Method and apparatus for controlled pumping of bentonite around a pipe jacked tunnel
US5632575A · kind A · utility
16Cited by
9References
10Claims
0Family size
Inventors
Key dates
| Filing date | Aug 30, 1994 |
| Grant date | May 27, 1997 |
| Priority date | — |
| Expiry date | Aug 30, 2014 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21D11/105
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An apparatus and method for selectively injecting a liquid bentonite slurry around an exterior of a tunnel liner segment which is pressed into a tunnel being concurrently excavated during a pipe jacking installation. The bentonite slurry lubricates the exterior of the tunnel liner reducing the force required to press the tunnel liner into the tunnel. The apparatus allows an operator of the pipe jacking operation to selectively inject bentonite around individual tunnel liner segment or to allow the apparatus to selectively inject bentonite as required by a preset injection pressure threshold value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.