高速铁路隧道超浅埋下穿高速公路盖挖法修建技术研究

高速铁路隧道下穿高速公路施工,存在交角越来越小、埋深越来越浅、隧道断面越来越大、施工周期越来越长、安全风险越来越高的特点。文章依托某高速铁路隧道超浅埋下穿高速公路的实际情况,系统研究了下穿段的建造技术,提出了盖挖法修建技术,其技术内容为:分区域封闭隧道上方高速公路的部分路面,未封闭路面保持车辆正常通行;分区域施工封闭区域的围护结构和路面盖板,使下穿段高速公路全部铺设盖板,恢复整个下穿段高速公路的正常通行;在围护结构和盖板的保护下开挖基坑,在基坑内施作隧道主体结构;回填隧道主体结构顶部与盖板之间的空隙,从而完成超浅埋下穿高速公路大跨度盖挖法的隧道施工。本技术通过分区域封闭隧道上方的高速公路路面,不影响道路的正常交通,占用道路时间短,无需道路改移,施工方法安全可靠,隧道施工对周边环境影响极小。

Study on Cover-cut Method for the Super-Shallow High-speed Railway Tunnels beneath an Expressway

The construction of high-speed railway tunnel beneath an expressway is characterized by small intersec⁃tion angle,shallow buried depth,large section,long construction period and high safety risk.Based on the situation of certain super-shallow high-speed railway tunnel beneath an expressway,it systematically studies the construc⁃tion technology and proposes a cover-cut method:partial road of expressway above the tunnel is closed by regions and the unclosed road keeps normal traffic;the envelop enclosure and cover plate of road in the closed area are con⁃structed by regions to make the whole section of expressway underneath be paved with the cover plate and resume normal traffic;the foundation pit is excavated under the protection of envelop enclosure and the cover plate,and the tunnel main structure is constructed in foundation pit;gap between top of tunnel main structure and cover plate is filled so as to complete the cover-cut construction of the super-shallow tunnel with large span beneath an express⁃way.With this technology,the road of expressway above the tunnel is closed by regions,with short occupation time,no effect on normal traffic,unnecessity of road change,and little environmental impact.