Tunneling

Tunnelling and Underground Construction

1-component Hydro-Active polyurethane injection resins

Easy to use, environmentally friendly polyurethane injection resins. Our one-component polyurethane injection resins come in 3 distinct ranges for different applications during tunnelling operations:

• Water cutting and water control
• Waterproofing of the concrete structure
• Consolidation and stabilisation of unstable zones in the drill face area.

Requiring simple 1-component injection equipment, our 1-component injection resins have adjustable reaction times to allow full adjustability during the application. Several specially developed tunnelling techniques such as Combi-Grouting in rock faces allow time and money to be saved in case of problems during the tunnelling operation.

2-component polyurethane injection resins for Rock Stabilisation

Fast reacting 2-component polyurethane injection resins for void filling, structural void filling, anchoring rock bolts and rock consolidation. Alternative ultra fast reacting resins are available to provide fast waterproofing of large leaks in combination with large voids. Variable reaction times and expansion rates allow the right product to be chosen to solve the problem at hand. 2-component resins are fast track solutions when it is impossible for the construction or tunnel operation to wait for cement to cure to sufficient strength.

2-component Organo-mineral injection resins

CFC-free, foaming or non foaming organo-mineral resins are used for fast consolidation and void filling in large areas where low polymerisation temperatures are required. Ideally suited for prevention and repair of collapses in tunnels and in specific mining applications.

Poly-acrylate resins

2-component low viscosity poly-acrylate injection resins are used for waterproofing curtain injections, soil coagulation and repairing leaks in tunnel liners between shotcrete faces in NATM tunnels.

Epoxy injection resins

2-component epoxy injection resins for structural injections in concrete tunnel segments or in-situ poured concrete.

Colloidal silicas

Advanced technology alternative for classic water glass and silicate injection grouts. Colloidal silica grouts have lower overall pH and are less susceptible to syneresis than normal sodium-silicate grouts. Low viscous liquids, colloidal silicate grouts are used for temporary waterproofing soils and areas before the tunnel shield.

Tunnelling operations, excavation and other underground construction operations quite often run into loose soil, fractured rock, collapse or large water inflows. Even with the best possible preparation and engineering studies, these problems can cause delays or stop the operation all together until a remedial action is found or taken.

Delays caused by collapses or water leaks, push back the other operations, cause logistical problems and need to be solved as soon as possible to allow normal operations to continue.

Although many problems can be solved using standard techniques and cement injections, chemical grouts are sometimes necessary because of the amount and velocity of the in flowing water, permeability of the soil or curing time restriction of the selected mineral grout.

Le Fong have over 10 years experience in manufacturing high grade chemical grouts for waterproofing, water blocking and consolidation of underground constructions and tunnels. The solution however is not only restricted to selecting the correct grout, you also need the equipment, tools and expertise to apply the grout successfully.

The long standing expertise of Le Fong in consulting, engineering and application of the selected grout using techniques, which have been proven by the large number of references, such as:

• Stabilisation, consolidation and void filling
• Pre and post grouting
• Umbrella injections
• Combi-Grouting
• Water control
• Rock bolting