Abstract: Adverse geological conditions such as isolated boulders and aged pile foundations pose challenges to shield tunneling speed and construction safety. To address this issue, a passive source seismic wave detection method using shield tunneling noise as source is proposed. Focusing on propagation patterns and characteristics of shield tunneling noise in soft soil environments, a passive source wavefield recovery method is proposed, and an advance observation technique for lead and wavefields suitable for shield tunneling environment is established. Based on effective passive source seismic data, this approach is characterized . Key findings include: (1) The proposed approach extracts effective reflection waves from tunneling noise for geological exploration, providing a novel approach for advance geological prediction in shield tunnels. (2) A noise source detection imaging method incorporating cross-correlation interferometry and diffractive superposition offset imaging is developed, achieving visualized imaging of adverse geological conditions ahead of tunnel face. (3) Field tests conducted at Suzhou East tunnel of the Tongzhou-Suzhou-Jiaxing-Ningbo high-speed railway successfully mapped pile foundation distribution patterns on both sides of the tunnel, with numerical simulations verifying the results′ consistency and providing reliable geological information for construction.

Key words: shield tunnel, passive source seismic wave method, adverse geological detection, pile foundation detection, high-speed railway tunnel