沿海复合地层泥水盾构施工适应性分析

Adaptability Analysis of Slurry Shield Construction in Coastal Composite Strata

以沿海广深港客运专线狮子洋隧道为工程依托,分析软土地层、软硬不均地层、全断面硬岩地层、断层破碎带4种典型地层条件下,大直径盾构隧道掘进中遇到的问题。结果表明:软土地层适合采用泥水平衡盾构掘进,掘进速度较快;在软硬不均地层中掘进时须对边刀间距进行优化并适当调整刮刀与滚刀的高差;全断面硬岩地层中掘进速度较慢,刀具磨损严重;在断层破碎带施工时须加强刀盘驱动系统和推进系统的最大承受荷载,根据地层变化不断优化掘进参数,维持掌子面的泥水压力,保证复杂地质条件及恶劣工况下盾构的掘进。研究结果对类似工程特别是沿海地区盾构隧道施工有借鉴意义。

Taking Shiziyang Tunnel of coastal Guangzhou-Shenzhen-Hong Kong passenger dedicated railway as the engineering dependence,the problems encountered in large-diameter shield tunnel excavation were analyzed under four typical stratigraphic conditions including soft soil stratum,soft-hard uneven stratum,full-section hard rock stratum and fault fractured zone.The results show that mud-water balance shield tunneling is suitable for soft soil stratum,and the tunneling speed is fast.It is necessary to optimize the spacing of edge cutters and adjust the height difference between scraper and hob properly when tunneling in soft-hard uneven stratum.Tunneling speed is slow and tool wear is serious in full-section hard rock stratum.In the construction of fault fractured zone,the maximum tolerable load of cutter head drive system and propulsion system should be strengthened,tunneling parameters should be continuously optimized according to stratum changes,mud-water pressure on the tunnel face should be maintained,which could guarantee the shield tunneling under complex geological conditions and adverse working conditions.The research results can be used as a reference in similar projects,especially in the construction of shield tunnels in coastal areas.