Recently, a large-diameter single-shield TBM jointly built by CRCHI and China Railway 11th Bureau Group for the Fuzhou Binhai Express Line helped the right line of the Zhenfengshan Tunnel achieve a smooth breakthrough, making it the first section on the entire line to complete both the 4.53-kilometer-long Daxiangshan Tunnel and the 1.5-kilometer-long Zhenfengshan Tunnel.

CRCHI Single-Shield TBM Helps Tunnel Breakthrough

The Daxiangshan Tunnel and Zhenfengshan Tunnel completed this time are rare mountain tunnels in China's urban rail transit constructed using long-distance, large-diameter TBM methods. The geological environment along the tunnel section is complex, presenting multiple construction challenges, including long-distance crossing of full-face extremely hard rock (maximum rock strength exceeding 220 MPa), passing through several fault fracture zones and densely jointed zones, crossing beneath the Shenhai Expressway, and passing near existing railways and elevated structures, greatly increasing construction difficulty.

To adapt to complex geology and changes in the surrounding environment, with strong support and assistance from the owner, experts, and the construction unit, CRCHI completed a variety of targeted designs for the single-shield TBM, including an ultra-heavy-duty cutterhead, a high-performance main machine, a rapid mucking system, and multi-level reinforcement measures, meeting the needs for rapid excavation in long-distance hard rock, efficient muck transport, and rapid backfilling.

CCTV Special Report

Since launch, the single-shield TBM has overcome adverse conditions such as a narrow site, passing beneath a mountaintop reservoir, railways, the Shenhai Expressway, elevated structures, shallow cover sections, fault fracture zones, and densely jointed zones. It has tackled one "hardest bone" after another along the entire line and conquered one construction "natural hazard" after another in the mountains. Under the meticulous organization and construction of China Railway 11th Bureau Group, the CRCHI single-shield TBM set the Fuzhou Binhai Express Line TBM records for the highest single-day excavation advance of 23.4 meters and the highest single-month excavation advance of 450 meters. It also set an industry record of 2,000 consecutive rings of single-line excavation with "zero fragmentation and zero leakage," overcoming multiple cutting-edge technical challenges in China and attracting a CCTV special report.

Single-Shield TBM Factory Acceptance

CRCHI provided comprehensive support services for equipment construction, effectively solving a series of construction challenges such as a small launch site, crossing fault fracture zones, passing beneath important structures, long-distance hard rock excavation, and efficient rock breaking, providing strong guarantees for the tunnel section breakthrough and the smooth implementation of the project.