1.Project Summary
Wanfeng supplied ground- support products and technical support for contract 1103 of Hong Kong’ s Shatin to Central Link railway tunnel. The approximately 3.88-kilometre contract section linked Hin Keng and Diamond Hill and ran under developed areas with varying ground conditions. It was excavated using both tunnel boring machine (TBM) and drill- and-blast construction methods. Ground reinforcement, pre-support and excavation stabilization were required through some sections of weaker or variable rock.
Provided products and solutions included self-drilling anchors, fiberglass rock bolts, self-drilling friction bolts, lattice girders and pipe umbrella support. They were used to enhance ground stability, control deformation related to excavation and safely advance through sections of poor or changing ground conditions.
2.Project Details
Project: Shatin to Central Link—SCL Contract 1103
Location: Hong Kong, China
Tunnel section: Hin Keng to Diamond Hill
Approximate total length: 17 km
Contract length: ~3,877 m
TBM size: ~7.4 m in diameter
Construction: TBM and drill-and-blast excavation
Application: Underground railway tunnel ground support
Products supplied: Anchors, fiberglass rock bolts, friction bolts, lattice girders and pipe umbrella systems
3. Project Background
Hong Kong’s Shatin to Central Link railway was constructed to serve numerous districts throughout the city. Spanning a total length of about 17 kilometres, the railway line would link together the areas of East Kowloon, the New Territories, and northern Hong Kong Island.
To pass beneath existing urban areas, much of the railway route had to be constructed underground.
Contract 1103 included tunnel construction between Hin Keng Station and Diamond Hill Station including tunnels associated with the Fung Tak Public Transport Interchange. Contract 1103 connected to Diamond Hill Station, a major public transportation hub located in the East Kowloon district of Hong Kong.
The two tunnel tubes were excavated using a 7.4 metre tunnel boring machine along a section approximately 1,695 metres long. A second section approximately 2,182 metres long was excavated using drill- and-blast techniques.
4. Engineering Challenges
Tunnelling beneath densely urbanised areas called for predictable ground support and deformation control. Ground movement was also controlled by zones of weaker ground and changes in geology throughout the tunnel alignment.
This project’s three main challenges were:
4.1 Changing Ground Conditions
Along the tunnel route there were changes to rock and soil conditions. This meant tunnel support had to accommodate both stable rock formations and weaker, more deformable ground conditions.
4.2 Certified Products Only
Products used for ground support on major projects in Hong Kong are subject to strict certification processes. Specifications, test and certification reports and auditable manufacture records were all submitted and assessed by our engineers.
4.3 Stable Excavation
The drill-and-blast excavation method can cause instability around the tunnel perimeter. Pre-support and effective reinforcement were key in ensuring stability around the excavated tunnel profile.
5. Ground-Support Case Study – Wanfeng
Solution Summary
Wanfeng provided a full suite of tunnel reinforcement products to accommodate varying geologic conditions and applications.
5.1 Self-Drilling Anchors
Self-drilling anchors featured a mechanical design that combined drilling, anchoring, and grouting into one process. Suitable for fractured or loose ground conditions where a conventional borehole could cave-in prior to anchoring, this system allowed for improved installation efficiency while actively reinforcing the surrounding groundmass.
5.2 Fiberglass Rock Bolts
Made from fiberglass, these rock bolts offered corrosion resistance, high tensile strength, and excellent cuttability. Fiberglass bolts were used in applications involving temporary rock support and areas where the reinforcement would need to be excavated by a tunnel boring machine (TBM).
5.3 Self-Drilling Friction Bolts
Self-drilling friction bolts provide immediate support to the surrounding ground through full contact with the borehole wall. This installation speed allowed the system to be used in both spot rock stabilization applications and short-cycle tunneling excavation.
5.4 Lattice Girders
Lattice girders are passive support installed around the perimeter of the excavated tunnel. Used in combination with shotcrete and rock reinforcement, lattice girders help maintain tunnel geometry while distributing loads around the perimeter of the excavation.
5.5 Pipe Umbrella Pre- Support System
Pipe umbrella units were installed ahead of the tunnel face in unstable soil or weak rock conditions. Installed parallel to the tunnel length above the planned excavation, these pipes created a canopy of support above the tunnel work area. The umbrella helped move loads away from the unsupported tunnel face and limit deformation caused by excavation.
6. Quality & Technical Support Assurance
For projects such as infrastructure applications, performance claims should be backed up with clear and auditable documentation. The support provided by Wanfeng’ for this project included relevant product specifications, material paperwork, quality-control documentation and installation guidance.
Technical support was also provided during installation and coordination of systems, by experienced personnel who assisted the construction team to install the specified support products in line with engineering specifications.
7. Project Result
Active reinforcement combined with passive support and advance pre-support gave the tunnel works at SCL 1103 a complete ground-control solution.
Benefits of supplied systems include:
This tunnel-support project highlights Wanfeng’ successful integration of engineered products with quality documentation and application specific technical support for complex underground railway projects.
8. Why Select Wanfeng for Tunnel Ground Support?
Wanfeng provides ground-support products for tunnel applications including railways, highways, mines, underground caverns and other geotechnical projects.
We offer:
Searching for ground support products for your next underground project? Let Wanfeng know about your geologic conditions, engineering requirements and procurement needs.
9. FAQ
Q1: What ground-support products were utilized on the SCL 1103 tunnel?
Ans: The ground-support solution consisted of self-drilling anchors, fiberglass rock bolts, self-drilling friction bolts, lattice girders and pipe umbrella components which were used for rock reinforcement, stabilization of the excavation profile and advance ground control.
Q2: Why would pipe umbrella systems be installed in poor ground conditions?
Ans: Pipe umbrella systems create a reinforced canopy installed ahead of the excavation face. It redistributes loads along the longitudinal direction of the tunnel, increases stability of the working zone and limits ground deformation during excavation.
Q3: Are tunnel support products customizable?
Ans: Yes. With proper engineering review and available manufacturing capacity, tunnel support product length, diameter, steel grade, connection style, surface treatment and accessories can be modified to your project’s needs.
