Supporting, sealing and water tightening
Injection operations cover an extensive range of applications, from waterproofing to crack sealing and ground-rock consolidations. Water inflows in tunnel structures represent major hazards, also hindering and delaying excavation and rifting processes. Sika provides an extensive range of solutions including services and tools to make tunnelling operations safe, fast and dry. Sika injection systems contain powerful technology to consolidate and stabilise the ground to prevent and/or solve any water income and any ground/rock consolidation need.
Synthetic injections
There are three key success factors to ensure the effectiveness and durability of injection works. The injection materials, the injection equipment and the injection method. These must all be used in the right combination and this is what Sika provides for tunnelling and mining applications including:
- Cavity & void filling
- Soil/ground stabilisation
- Rock mass stabilisation
- Permanent ground consolidation
- Waterstopping – under hydrostatic pressure
- Controlling over-blasting
- Underpinning
Water sealing injections
The SikaFix® range includes 2-component polyurethane resins which penetrate and cure to consolidate and stabilise fault zones. In situations with high water ingress, SikaFix® 2-component PU is a particularly powerful solution due to its special formulation, giving slight foaming properties in contact with water to expand and very effectively stop the inrush. This modular system also includes accelerators which can be used to increase the foaming factor and to adjust the time needed for this expansion.
Consolidation and filling cavities
The SikaFix® range also has a silicate based injection that is designed with a high expansion factor. This helps to fill and stabilise large voids and to give additional support to the roof and ribs of the excavated structure. The stabilising effects of the SikaFix® range ensure a faster and safer construction process. The range also includes polyurethane foam resin designed for the filling and stabilisation of smaller voids and smaller cavities. It also expands both with and without water.