TOMAS - Cut and cover tunnel technology

The TOMAS Surface Tunneling technology is based on three innovations:

1. Building a semi circular tunnel from the surface in soils with high water table without draining or pumping out the sub-surface water.
2. Removing the soil mixed with water within a half round shield with standard cutter dredging technology adapted for this application.
3. Using standard segmented tunneling sections to shape the tunnel, but fixing these segments with post-tensioning under a continuous precast or cast on site concrete beam fixed and supported or held by rakes of piles.

Benefits of this technology are:

- Short construction time because of fast building (50-80 mtrs/day)
- Low investment cost
- Limited construction space required
- No ground dewatering required
- Soil removal by dredging is the cheapest way of moving soil
- Material transport can be done through finished tunnel
- Minimum impact on the environment
- Use is made of well-known technologies
- Innovative construction method with international potential

Current contact for technology licensing:
Ing. Jaap H. Ketel,
NEDLAND BV
3831 PB LEUSDEN
The Netherlands
Tel. +31.33.43 43 500
Fax. +31.33.43 43 501
Mob. +31.6.532 61 771