浅谈膨胀土超浅埋、大断面隧道进洞施工关键技术

Discussion on the Key Technology of the Super Shallow Buried and Large Section Tunnel Entry Construction with Expansive Soil

蒙华铁路红土岭隧道出口段采取洞口排水及黏土层封闭、加强地表及洞内监控量测、采用长大管棚超前支护、三台阶临时仰拱开挖、钢格栅柔性支护,及时形成洞口锁口圈等一系列工艺方法,确保膨胀土超浅埋大断面隧道安全进洞,可为类似隧道施工提供借鉴。

A series of technological methods are adopted in the exit section of the Hongtuling tunnel of the Inner Mongolia-Jiangxi railway,such as the drainage at the entrance of the tunnel and closure of the clay layer, strengthening the monitoring and measurement of the surface and the inside of the tunnel, adopting long pipe shed advanced support, three-step temporary inverted arch excavation, flexible steel grille support, timely forming the entrance lock ring and so on, so as the safe entry of super shallow buried and large section tunnel with expansive soil, which can provide reference for the similar tunnel construction.