Description
The additives and the polymers have been developed by CONDAT to cope with complicated geologies such as sticky, abrasive or very permeable ground.
In the most complicated cases:
- very abrasive rocks
- very sticky clay
- ground supersaturated with water...
the use of additives and polymers can provide effective treatment as a complement to the foam. These additives for foaming agents improve the productivity of tunnel boring machines.
Clayey ground
In the case of clayey ground, sticking is a phenomenon that can reduce the speed of the tunnel boring machine and create clogging at the centre of the head or in the chamber. In parallel with the foam, it is possible to use an anti-sticking additive which is diluted online in the foaming solution.
Granular ground
For granular ground saturated in water, segregation between water and mud can occur. In this case, a polymer can be injected into the excavation chamber to correct the free water content and obtain homogeneous spoil.
