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