Large cross-section weak surrounding rock tunnel three-step and six-part short-distance construction method

A technology of weak surrounding rock and construction method, applied in the direction of tunnel, tunnel lining, earthwork drilling and mining, etc., can solve the problems of poor self-stabilizing ability of weak surrounding rock, large deformation of initial support, slow progress of construction period, etc., which is beneficial to control The effect of deformation, less one-time investment and large construction space

Active Publication Date: 2012-07-11
CCCC SECOND HIGHWAY ENG CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the construction problems encountered in the current construction of high-speed railway large-section soft surrounding rock tunnels, provide a new construction method, and optimize the traditional three-step sub-section flow operation technology to solve the complex process of the existing technology , the shortcoming of the slow progress of the construction period, overcomes the construction problems such as poor self-stabilization ability of the weak surrounding rock, large initial support deformation, etc., effectively uses resources, saves costs, and realizes safe, fast and economical construction of large-section tunnels

Method used

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  • Large cross-section weak surrounding rock tunnel three-step and six-part short-distance construction method
  • Large cross-section weak surrounding rock tunnel three-step and six-part short-distance construction method
  • Large cross-section weak surrounding rock tunnel three-step and six-part short-distance construction method

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Effect test

Embodiment 1

[0035] The construction method of three steps and six sections of large section and weak surrounding rock tunnel is short-distance construction method. The excavation section is divided into three steps and six working faces. Excavation, support operation, inverted arch and filling operation are carried out at the same time. The schedule of each process is reasonable, and the secondary The lining is followed up in a timely manner, and the construction of the upper, middle and lower steps is promoted synchronously, such as figure 1 , figure 2 , image 3 As shown, it mainly includes the following steps:

[0036] (1) The upper step 1 of the upper arc-shaped pilot pit is excavated in the circumferential direction, and the earthwork excavated by the upper step 1 is transferred to the lower step;

[0037] (2) After the upper step 1 lags by 4.5-5m, excavate the left part 2 of the middle step, and transfer the excavated earthwork to the lower step;

[0038] (3) After the left part...

Embodiment 2

[0044] In step 1, the upper step 1 of the upper arc-shaped pilot pit in the circumferential excavation is performed by using the steel frame erected in the previous cycle as a small conduit of Φ42 ahead of the tunnel arch, which is carried out after the arch is supported in advance.

[0045] The advanced small pipe is made of hot-rolled seamless steel pipe with Φ42mm and wall thickness of 3.5mm, with a length of 3.5m, a circumferential spacing of 30-50cm, and its longitudinal overlap length is not less than 1m; 12°, can be adjusted according to the actual situation. The drilling direction should be straight. The diameter of the drilled hole is not less than 45 mm; the leading small conduits are installed within 120° of the arc of the tunnel arch, with a total of 38 pieces, the circumferential spacing is 40 cm, and the longitudinal overlap length is not less than 1 meter.

[0046]The excavation contour shape and section size of the upper step 1 shall be staked out accordin...

Embodiment 3

[0055] In step 2, the excavation height of the left part 2 of the middle step is controlled at 3.3-4m. After excavation, the initial support of the working part is carried out in time according to the method described in Example 2, that is, the initial spraying of 4cm thick concrete, hanging steel mesh, and lengthening Steel frame, and at the lower part of the arch foot of the steel frame close to the edges of both sides of the steel frame, press the inclination angle of 45° and 60° to set up locking anchors 7, the length of the anchors is 4m, and each ring is 8, the locking anchors 7 Firmly welded with the steel frame to increase the support force of the arch foot.

[0056] In step 3, the excavation height of the right part 3 of the middle step is controlled at 3.3-4.0m, and the method used is the same as the excavation and support method of the left part 2 of the middle step, and the lower part of the arch foot of the steel frame is close to the edges of both sides of the ste...

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Abstract

The invention discloses a large cross-section weak surrounding rock tunnel three-step and six-part short-distance construction method, which comprises the steps as follows: (1) annularly excavating an upper step of an upper part arc pilot tunnel, transferring excavated earthwork of the upper step to a lower step; (2) excavating a left part of a middle step about 4.5-5 meters behind the upper step, and transferring excavated earthwork to the lower step; (3) excavating a right part of the middle step about 3-4 meters behind the left part of the middle step, and transferring excavated earthwork to the lower step;(4) excavating a left part of the lower step about 6-8 meters behind the left part of the middle step or about 3-4 meters behind the right part of the middle step, and conveying excavated earthwork of the left part of the lower step out of the tunnel; (5) excavating a right part of the lower step about 3-4 meters behind the left part of the lower step, and conveying excavated earthwork of the lower step out of the tunnel; and (6) excavating the rest part of the tunnel bottom about 20-25 meters behind the right part of the lower step, excavating continuously according to the steps in a circulating and interlacing manner, and finally realizing tunnel excavating construction. The method can be used for building a large cross-section tunnel in a safe, rapid and economic manner.

Description

technical field [0001] The invention relates to a tunnel excavation construction method, in particular to a short-distance construction method for three steps and six sections of a high-speed railway large-section soft geological surrounding rock tunnel. Background technique [0002] In recent years, the state has stepped up the construction of railway passenger dedicated lines in the western region, which has many mountains and complex geology. The number of many long tunnels has increased, and the average length of line tunnels is 30%-70% of the entire line. The surrounding rock grades IV and V account for a large proportion of the tunnel body geology, and the construction safety risk is high. For the excavation section is 138m 2 -146m 2 For railway tunnels with large excavation sections and weak geological surrounding rocks, reliable construction methods must be adopted to ensure the safety of tunnel construction. [0003] In order to control and reduce the safety ac...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): E21D9/00E21D11/10
Inventor 夏润禾何建宏许前顺边玉良丰小平李军周云徐向叶
Owner CCCC SECOND HIGHWAY ENG CO LTD
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