高速铁路浅埋偏压隧道安全进洞方案研究

A safe entrance scheme of shallow buried biastunnels on high-speed railways

摘要:

针对傍山浅埋偏压、局部出露地表隧道工程合理施工方案的选取问题,结合现场工程地质及施工环境条件,提出“先在出露地表侧预设钢格栅混凝土护拱,随后反压回填土石,采用暗挖法进洞”的护拱暗挖技术方案,并与放坡明挖、支挡明挖方案进行对比分析。研究结果表明,明挖施工方案虽技术成熟,但用于此类隧道面临着靠山侧高陡边坡开挖及防护工程量大、生态环境扰动范围广、施工及运营风险高等问题;护拱暗挖进洞方案开挖及防护工程量小、环境保护效果好、安全风险低,可保障傍山浅埋、局部出露地表隧道的安全快速进洞。研究成果可为类似条件下的隧道工程建设提供参考。

Abstract:

In this paper, the selection of reasonable construction scheme for shallow buried bias tunnels with partially exposed surface was discussed. Combined with the on-ite engineering geology and construction environmental conditions, a technical scheme with the arch tunneling method was proposed: steel grating concrete retaining arches were preinstalled on the exposed surface side, then the earth rock was backfilled as back pressure, finally the tunnel portal was constructed by the tunneling method. The comparison results between the proposed scheme and the open-cut construction schemes showed that, although the open-cut construction scheme is technically mature, it is faced with some problems, i.e., large quantities of excavation and protection, wide range of ecological environment disturbance, high construction and operation risks, etc. The arch tunneling construction scheme can not only overcome these problems, but also ensure the safe and rapid entrance of shallow buried bias tunnels. The research results can provide a reference for tunnel construction under similar conditions.