Method for constructing reinforced surrounding rock inside precast-segment tunnels

Abstract

The invention discloses a method for constructing reinforced surrounding rock inside precast-segment tunnels. The method includes: embedding a precast formwork shell used for anchor rod construction in a precast reinforced concrete segment, drilling a hole in the surrounding rock via the precast formwork shell, and arranging one thrust piece at an end port of the precast formwork shell during the drilling process so as to reduce impact from transverse vibration of a drilling rod to the precast formwork shell; arranging one hollow grouting anchor rod in the hole drilled in the surrounding rock after the hole is drilled, arranging a grout stopping device on the hollow grouting anchor rod and connecting the same with a grouting joint pipe, and grouting the hole drilled on the surrounding rock to reinforce the same; after the grouting, taking down the grouting joint pipe, and arranging a detachable water stopping device at the end port of the precast formwork shell. The method has the advantages that a main structure of a tunnel and the anchor rod are tightly combined and form a bearing body commonly with the reinforced surrounding rock, influence from the construction to stability of the precast-segment tunnel is low, and the water stopping device is replaceable and good in waterproof effect.

Description

technical field [0001] The invention belongs to the technical field of underground engineering construction, and in particular relates to a construction method for reinforcing surrounding rock in a prefabricated segment tunnel. Background technique [0002] A coal mine transportation inclined shaft is excavated by a TBM roadheader. The shield tunnel is constructed with reinforced concrete prefabricated segments. That is, the reinforced concrete prefabricated segment meets the opening construction requirements in consideration of the lateral direction), and the reserved opening size is 4.4m in height and 7.5m in width (the ring width of the reinforced concrete segment is 1.5m); ② requires first-class waterproofing. [0003] However, the above-mentioned design requirements have the following problems in the specific construction: first, the surrounding rock of the coal seam (at the opening) is broken and has poor stability, and there is a risk of landslide in the surrounding r...

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Problems solved by technology

[0003] However, the above-mentioned design requirements have the following problems in the specific construction: first, the surrounding rock of the coal seam (at the opening) is broken and has poor stability, and there is a risk of landslide in the surrounding rock during the opening construction; second, the size of the opening is large and needs to be removed 5-ring width size segment, and the height reaches 4.4m, so the cross-section of the reinforced concrete precast segment is extremely unstable

The disadvantage of using this reinforcement method is that directly drilling holes on the segment has a great impact on the integrity of the segment, and at the same time, the holes left by directly drilling anchor rods on the segment cannot meet the first-level waterproof requirements. Requirements, so that there is a hidden danger of water seepage in the tunnel

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