On the morning of November 11th, accompanied by the resounding roar of the tunnel boring machine (TBM), the "Yimeng" shield TBM, with a diameter of 3.82 meters, successfully broke through the rock. This breakthrough signifies the completion of the dual-line connection for the Shandong Guoneng Feixian County Heat Source Long-Distance Heating Pipeline Project, which tunnels under the Beng River in Linyi.

The project employed a slurry shield TBM to navigate the challenging task of crossing the river—a feat considering the project's significant burial depth, hard strata, and complex geology in the heating industry. The excavation involved weathered limestone with an average rock stratum strength of 80Mpa. The shield tunneling process traversed adverse and intricate geology, including moderately differentiated limestone, fractured zones, karst cave groups, and a composite stratum of upper-soft and lower-hard ground along the Beng River bed. Notably, the tunnel connects to the bottom of the Beng River, with a shallowest burial depth of only 1.2 meters. The cave formations exhibit developed fissures, high pressure, abundant water, and pose a considerable water permeability risk.

To address the unique geological challenges posed by the Beng River, Tangxing Technology developed the "Yimeng" small-diameter hard rock shield TBM. With a length of 53 meters, an excavation diameter of 3.82 meters, and a total weight of 185 tons, this TBM features a composite hard rock cutter head design. The innovative use of high-pressure sealing technology, reliable main drive technology, and small-diameter assembly technology distinguishes the "Yimeng" shield TBM as the smallest diameter shield TBM currently operating in Shandong Province.

This project, a focal point in Linyi's "14th Five-Year Plan" energy development initiative, holds significant implications. Upon completion, it will address heating source constraints in the northern urban area of Linyi, ensuring the fulfillment of mid- and long-term heating development needs for the Beicheng New Area.