STEEL PIPE MULTI STEP GROUTING DEVICE OPEN AND CUT AND NATM COMPLEX EXCAVATION TUNNEL CONSTRUCTION METHOD

摘要

The present invention has a purpose to provide an open cut excavation using a steel pipe multi-stage grouting device and a method to construct an NATM complex excavation tunnel. The present invention is configured to proceed an excavation process without an open cutting of a middle part of a tunnel by reinforcing a tunnel crown part and a steel pipe multi-stage with an installation of reinforcing iron bars, shotcretes and reinforcing supports as there is a worry of occurring public discontent due to a delay of the process due to a delay of compensation for an entrance road site in an open cutting section, and noise and vibration from the construction of a pithead part. To achieve the above purpose, in accordance to the present invention, the open cut excavation using a steel pipe multi-stage grouting device and a method to construct an NATM complex excavation tunnel comprises the steps of: forming a boring hole by boring an upper half of a tunnel, and inserting a steel pipe multi-stage grouting device into the boring hole and filing the steel pipe multi-stage grouting device with mortar; installing a lattice support to a half part of a tunnel separated at a certain distance from the steel pipe multi-stage grouting device, arranging reinforcing iron bars on the lattice support, installing wire meshes on the reinforcing iron bars, installing plywood on the wire meshes, installing a shotcrete injection hole on the plywood, casting a first shotcrete on the lattice supports, casting a second shotcrete on the first shotcrete, removing the plywood, casting a third shotcrete in the shotcrete injection hole, and constructing a lining concrete for casting and curing concrete on the lattice support.