Tunnel excavation method of soft ground of city area

摘要

Tunnel excavation method of soft ground of city area in order to make stable and short time excavation of tunnel with shallow depth from the ground surface in soft ground where the building,;In this method, the concrete wall body 4 is placed in a space formed by excavating the advanced gangway 2 by a sidewall gangway method, and the tunnel-excavation is performed. Next, the center-side top portion 8 of the tunnel is excavated, A steel rib 10b provided with an arching correction means 16 is installed on the inner circumferential surface of a space formed by excavating the annular portion 12 of both side walls to form a steel rib 10a on the concrete wall body 4 The steel ring 10a is integrally connected to the steel rib 10a and the arching correction means 16 changes the curvature of the steel ribs 10a and 10b to be in close contact with the inner circumferential surface of the tunnel A plurality of steel pipes 18 are buried in the ground along the outer surface of the steel ribs 10a and 10b provided in a semicircular shape so as to be installed on the inner periphery of the tunnel, Excavation surface reinforcement to stabilize In order to make it happen.