Construction method conversion construction method of super-large-span tunnel in V-level to IV-level surrounding rock section

Abstract

The invention discloses a construction method conversion construction method of a super-large-span tunnel in a V-level to IV-level surrounding rock section. The elevation of an excavation arching lineis controlled to be consistent; in transition section construction, a left pilot tunnel temporary middle wall and a right pilot tunnel temporary middle wall on the two sides of a pilot and a rear pilot in a surrounding rock double-side-wall pilot tunnel method simultaneously move towards the middle of the tunnel until the left pilot tunnel temporary middle wall is in contact with the right pilottunnel temporary middle wall, and foot locking anchor rods are applied to the two sides of a temporary inverted arch; and then the right pilot tunnel temporary middle wall is removed, and the left pilot tunnel temporary middle wall is reserved as a middle temporary middle wall of a CRD method. According to the method, a double-side-wall pilot tunnel method is transversely transited to the CRD method through a gradual change method, the time interval between construction method conversion is avoided, and disturbance of later removal of temporary supports of the double-side-wall pilot tunnel method to surrounding rock is reduced; and therefore the construction speed is increased, the construction period is shortened, enforced idleness due to poor organization of work is avoided, and economicbenefits of tunnel construction are improved.

Description

technical field [0001] The invention relates to traffic fields such as highway tunnels and underground engineering technology, and in particular relates to a construction method for super-large-span highway tunnels in the construction method conversion of level V to level IV surrounding rock sections. Background technique [0002] In the process of highway tunnel and underground engineering traffic construction, it is often necessary to select different excavation methods according to different geological conditions of the surrounding rock of the tunnel, but the conversion between different excavation methods has been ignored, and there is no domestic design of ultra-long-span highway tunnels. , Construction codes and standards. In actual construction, the conversion of construction methods has no basis and is chaotic, and problems such as conservative, slow speed, and high risk often occur in the replacement process of construction methods. [0003] In the conversion proce...

AI Technical Summary

Problems solved by technology

Moreover, when the temporary mid-wall moves sideways, due to the constant changes in the length and curvature of the mid-wall, the steel frame processing plant needs to continue to design and process, thus increasing the construction cost and prolonging the construction period

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