Home page

Shenzhen Metro Project | ~137 MPa Hard Rock

Shenzhen Metro Project

UCS ≈ 137 MPa, extremely hard rock

Tool life extended by 3×+, tunneling efficiency significantly improved

Category:

Tunneling Cutting Picks – Application Cases

Client Background

During construction of a Shenzhen metro project, the tunnel encountered the hardest rock stratum recorded in the project, equivalent to F14 grade with a UCS of approximately 137.2 MPa. During excavation, severe sparking occurred at the cutting face, commonly referred to on site as the “firewheel phenomenon.”

More than twenty cutting tool brands were tested successively, all of which failed within minutes. As a result, the project owner prepared to abandon the original excavation scheme.

Customized solutions

Facing extreme operating conditions that push the limits of comprehensive performance, Xinda has introduced a super-wear-resistant series of cutting picks specifically developed for extremely hard rock:

Optimized alloy: Use ultra-coarse-grained cemented carbide to withstand high-intensity impacts.

Strong dental body: Advanced heat treatment process prevents the shank from fracturing under extreme impact.

Reliable welding: Automated welding technology ensures that the alloy tip does not come loose even under extreme operating conditions.

Implementation Results

Key Challenge Overcome

The cutting picks maintained effective cutting performance over an extended service period, without rapid or widespread failure, enabling continuous and stable excavation operations.

Solution Continuity Secured

The solution successfully enabled the project to pass through the most challenging rock formations, ensuring continuity of the overall construction scheme and avoiding substantial losses associated with higher-cost alternative solutions.