关键词: 软岩隧道, 预应力锚索, 锚固性能, 参数设计, 工程应用

Abstract: Effective rapid support technology using high-strength prestressed anchor cables is crucial for soft rock tunnels.  A case study is conducted on the Muzailing highway tunnel, detailing the construction technology and critical aspects of the anchor cable system. The study includes an examination of cable support performance through field tensioning tests, proposes a basic design principle for support parameters, and identifies key design parameters. In summary, the use of high strength prestressed anchor cables in the Muzailing highway tunnel has yielded significant results. Some conclusions are drawn as follows: (1) The high-strength prestressed anchor cable system is composed of high-strength steel strands, base plates, anchorage, resin anchorage agents, and surface collaborative support components. Critical construction tasks include drilling, resin anchoring, prestress tensioning, monitoring, and fitting installation. (2) The prestressed anchor system provides rapid and high-strength support, with a 1.7 m-length anchor achieving a force greater than 300 kN. Installation of a 10 m anchor cable is completed within 1 h. (3) Numerical calculations of excavation with anchor cable support under severe compression show that the anchor cable system effectively controls deformation. (4) The advance support technology using high-strength prestressed anchor cables in the Muzhailing highway tunnel effectively controls the deformation of surrounding rock and accelerates construction progress.

Key words: soft rock tunnel, prestressed anchor cable, anchorage performance, parameter design, engineering application