China has set a new benchmark in underground rescue operations with its remarkable recovery of a stalled 16‑m diameter tunnel boring machine (TBM) beneath the Yangtze River. During construction of the 6.4‑km Jiangyin–Jingjiang Yangtze River Tunnel, the TBM suffered a catastrophic failure 54 meters below ground in water‑saturated, high‑pressure soft sediments. Normally these conditions make retrieval or repair impossible. Instead of abandoning the USD 50‑million machine, engineers launched a second TBM from the opposite bank and executed an extraordinarily precise underground docking, achieving just 2 mm of vertical deviation while navigating beneath one of the world’s largest rivers. The successful interception enabled crews to safely access the failed machine and continue tunneling, demonstrating unprecedented precision in long-distance TBM guidance and confirming that deep underwater TBM rescue is technically feasible. (Source: Geoengineer.org)
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