In tunneling and mining operations, water ingress and unconsolidated geology can present significant challenges. These conditions not only jeopardize the safety and integrity of the construction but also lead to costly delays and increased operational risks.
SikaInject® products together with the expertise of Sika offer a comprehensive solution for ground consolidation, stabilization, and effective water-stopping, ensuring that your underground projects proceed smoothly and securely.
Content index:
The Challenges: Water Ingress and Unstable Geology
The Use of Injection to Solve Problems
SikaInject®: Advanced Injection Materials for Tunnels and Mining
Types of Injection Methods and Their Uses
Choose the Right Products for Your Specific Problems
Advantages with Sika Injection Solutions
The Challenges: Water Ingress and Unstable Geology
Water ingress into tunnels, drifts, shafts or other underground structures can lead to serious issues such as erosion, weakening of the structure, and dangerous working conditions. Unconsolidated geology, with loose or fragmented rock formations, further complicates construction efforts by creating instability and increasing the risk of collapse.
The Use of Injection to Solve Problems
Injection techniques are crucial in addressing a range of challenges in tunnels and mines, including stopping water inrush, filling cavities, ground consolidation, soil stabilization, TBM heading support, and controlling over-blast. These solutions enhance structural stability and operational safety in underground environments.
Stopping water inrush
Ground consolidation
TBM heading injection
Cavity and void filling
Soil stabilization
Control of over-blast
SikaInject®: Advanced Injection Materials for Tunnels and Mining
SikaInject® products are specially formulated to address these critical challenges through a range of injection applications, including pre-injections and post-injections. Whether you need to stabilize the ground before excavation or stop water ingress after construction has begun, SikaInject® provides the reliability and performance required for successful tunneling and mining operations.
We provide the following four groups of technologies for different uses:
- Mineral, "inorganic" solutions
- Nanometric, colloidal silica
- Fast-setting microcement injection for pre-excavation grouting
- Non-foaming polyurethane resin for consolidation of unstable soil and rock
- Stopping unexpected high water-flow
- Modular system -- foam/ resin
- Foaming silicate for filling of big cavities and stabilizing of loose rock, waterproofing
- Non-foaming silicate resin, stabilizing, over-blast control, underwater applications
- TBM consolidation/ anchoring/ bolting
- Acrylate injection resins for consolidation of soil with low permeability
- Curtain injections, waterproofing
Types of Injection Methods and Their Uses
Pre-injection
Proactive ground consolidation and stabilization
Pre-injection is used before excavation begins. This method is essential for proactively consolidating and stabilizing loose ground and reducing or preventing water ingress during the tunneling or mining process.
Ground consolidation:
The injection material penetrates the ground, fills voids and binds loose soil or rock particles together. This results in a solidified mass that provides a stable base for subsequent excavation.
Water-stopping:
Pre-injection fills water-bearing areas. Thus, it reduces water inrush or ideally creates a waterproof barrier that prevents water from entering the excavation site, ensuring a dry, safe working environment and protecting the structural integrity of the tunnel or mine drift.
Post-injection
Reactive water-stopping and structural repair
Post-injection is used when water ingress or ground instability is detected after excavation has begun. This method is to provide a rapid and effective response, sealing leaks, filling voids, and stabilizing compromised ground conditions.
Structural stabilization:
Post-injection solutions reinforce weakened areas by filling voids and cracks, restoring stability to the structure and extending its service life.
Water-stopping:
The injection material is applied into existing cracks, joints, and voids, where they react to form a watertight seal. This stops the flow of water, preventing further damage and ensuring the safety of the operation.
Pre-Injection vs. Post-Injection
Pre-injection
- Purpose: prevent issues before they arise
- Typical area: in front of the tunnel face
- Dominated by cementitious injections
- Pre-injection is like an insurance, to avoid problems in the future
- Minimal risk of uncontrolled water inrushes
- Substantially improved stability through poor ground
- "Dry" working conditions in the tunnel
- No, or little influence on the surroundings
Pre-injection can solve almost all problems.
Target of 100% sealing is not realistic.
Post-injection
- Purpose: address challenges as they arise
- Typical area: somewhere on the tunnel surface
- Dominated by chemical injections
- Almost all tunnels require some kind of post-injection works either with micro-cements, PU or acrylates for leak sealing, repair or ground stabilization methods
- It is much easier to achieve good results with post-injection if the tunnel has been pre-injected
Post-injection alone may become more difficult, costly and is sometimes impossible.
As a supplement, it is very effective.
Choose the Right Products for Your Specific Problems
Pre-injection or post-injection?
Which materials should you use for your tunneling or mining project to address which problems?
If you want to get competent advice, contact our waterproofing and injection expert for solid technical advice.
Sika has extensive experience in a variety of project types across different countries. We also have local technical departments ready to support you on your job sites.
Author
Matthias Ohnesorge
Corporate Product Engineer
Target Market Waterproofing
Sika Services AG
Advantages With Sika Injection Solutions
Since Sika was founded in 1910, the company has been involved in the largest and most challenging underground construction projects around the globe. Delivering reliable and innovative solutions for the world’s mines and tunnels has been amongst the top business priorities ever since.
Today there are local Sika companies in over 100 countries with more than 160 production facilities supporting our global service and distribution network. Sika brings more than 100 years of underground construction expertise to your project – Building Trust.
Sika's injection expertise
- Site inspection and selection of the appropriate concept
- Selection of the correct material and application method
- Selection of the most cost-effective materials and methods to maximize our customers' benefits
- Detailed product and application documentation
Global presence and local support
- Local presence in more than 100 countries with 160 production facilities and regional technical service support centers
- Providing the most efficient logistics and supply routes
- Specialized tunneling and mining teams in all regions
On-site support
- Local Sika expert teams
- On site testing and support
- Quality control procedures and checklists
Technical and practical training
- Sika provides local training sessions at your site, specifically to enhance and optimize the full benefits of using Sika materials, technologies and application systems
