A method for dismantling tall and large cores in extra-large cross-section underground tunnels

Abstract

The invention provides a method for removing the tall core soil of an extra-large cross-section underground excavation tunnel, comprising the following steps: Step 1: excavating longitudinally along the upper part of the upper core soil side of the tunnel to form a first pilot pit; the first pilot pit is horizontal state; step 2: Excavate the upper core soil on the other side of the upper part longitudinally along the tunnel to form the second pilot pit in a horizontal state; push the first pilot pit and the second pilot pit to the excavation direction and excavate the upper core soil to form Vertical to the transverse channel of the first pilot pit and the second pilot pit; step 3: digging the first pilot pit to form a first step group comprising several steps, each step length of forming the first step group is 3-5m; step 4: Remove the upper core soil horizontally to form a full section of steps with a length of 6m; Step 5: Excavate downwards under the second pilot pit to form a second set of steps including several steps; Step 6: Invert the core soil Excavate and construct the second lining of the inverted arch; step 7: carry out the construction of the second lining of the large section of the tunnel.

Description

technical field [0001] The invention relates to the field of tunnel construction, in particular to a method for dismantling tall cores of super-large cross-section underground excavation tunnels. Background technique [0002] With the rapid development of our country, the construction of urban rail transit in the construction of municipal infrastructure involves more and more large-section shallow-buried tunnels, which has become a major feature of urban construction. How to quickly and safely Building underground tunnels in cities has become an urgent problem to be solved. [0003] In the prior art, there are mainly the following two methods for excavating tunnels: the CD method of ordinary excavation for extra-large section underground excavation tunnels is to divide the large section into left and right side walls, and carry out in sections, and complete the excavation of the left side wall to form the left side support and the central tunnel. Temporary support for parti...

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Problems solved by technology

[0004] The purpose of the present invention is to solve the problems in the prior art that the demolition of the high core soil of the tunnel is high risk, difficult, and difficult to remove the temporary support. In view of this, the purpose of the present invention is to provide a method for the removal of the large core of the super-large section underground excavation tunnel , this method can effectively improve the construction progress, and at the same time avoid the problem of difficult demolition due to the high core soil, ensure the construction traffic organization, convenient transportation, and the core soil can play a supporting role for the longest time limit, greatly improving construction safety and ensuring the building above Safety

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