Radial pre-grouting method before excavation of the lower steps of tunnels in confined water strata

A bench excavation and pre-grouting technology, applied in tunnels, earth-moving drilling, mining equipment, etc., can solve the problems of difficulty in ensuring grouting effect, increasing water seepage pressure of surrounding rock under the bench, increasing the difficulty of radial grouting, etc. , to improve the support operation environment, ensure the support quality, and improve the effect of grouting

Active Publication Date: 2020-04-17
中铁二局第二工程有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] Radial grouting for tunnels in confined water formations is carried out after excavation of the surrounding rock. When the step method is used for construction, the radial grouting construction of the upper step is completed after the excavation of the upper step, and the leakage point of the upper step surrounding rock is checked. Grouting plugging; after the excavation of the lower bench, the radial grouting water plugging is carried out on the seepage point of the lower bench. Grouting is difficult, and it is difficult to guarantee the grouting effect

Method used

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  • Radial pre-grouting method before excavation of the lower steps of tunnels in confined water strata
  • Radial pre-grouting method before excavation of the lower steps of tunnels in confined water strata

Examples

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Effect test

Embodiment 1

[0027] The radial pre-grouting method before the excavation of the lower step of the tunnel in the confined water stratum includes:

[0028] S1: After the initial support is excavated for the upper step, grouting holes for the upper step are opened, and the leakage point of the initial support is first drained with a grouting pipe, and then the upper step is radially grouted with the grouting pipe to the upper step. The thickness of the consolidation ring is 3m; the arrangement of radial grouting holes on the upper steps and the grouting process are determined according to the location, characteristics, water seepage and water pressure of the leakage point.

[0029] S2: Use the grouting pipe to carry out radial pre-grouting on the surrounding rock of the lower step 2m away from the working face, and the thickness of the consolidation circle of the lower step is 7m. According to the cracks at the seepage point of the upper step and the direction of the structural surface, the s...

Embodiment 2

[0033] The radial pre-grouting method before the excavation of the lower step of the tunnel in the confined water stratum includes:

[0034] S1: After the initial support is excavated for the upper step, grouting holes for the upper step are opened, and the leakage point of the initial support is first drained with a grouting pipe, and then the upper step is radially grouted with the grouting pipe to the upper step. The thickness of the consolidation ring is 4m; the arrangement of radial grouting holes on the upper steps and the grouting process are determined according to the location, characteristics, water seepage and water pressure of the leakage point.

[0035] S2: Use the grouting pipe to perform radial pre-grouting on the surrounding rock of the lower step 5m away from the working face, and the thickness of the consolidation circle of the lower step is 8.5m. According to the cracks at the seepage point of the upper step and the direction of the structural surface, the s...

Embodiment 3

[0038] The radial pre-grouting method before the excavation of the lower step of the tunnel in the confined water stratum includes:

[0039] S1: After the initial support is excavated for the upper step, grouting holes for the upper step are opened, and the leakage point of the initial support is first drained with a grouting pipe, and then the upper step is radially grouted with the grouting pipe to the upper step. The thickness of the consolidation ring is 5m; the layout of radial grouting holes on the upper steps and the grouting process are determined according to the location, characteristics, water seepage and water pressure of the leakage point.

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Abstract

The invention provides a radial pre-grouting method before excavation of a lower bench of a confined water stratum tunnel. The radial pre-grouting method before excavation of the lower bench of the confined water stratum tunnel comprises the following steps that S1, after the excavation of the upper bench and initial support are completed, upper bench grouting holes are formed, a leakage point ofthe initial support is drained by using a grouting pipe, then upper bench radial grouting is carried out on the upper bench, the thickness of an upper bench consolidation ring is 3-5m, and the arrangement of the upper bench radial grouting holes and grouting process are determined according to the position of the leakage point, characteristics, water percolating capacity and water pressure; S2, lower bench radial pre-grouting is carried out on the surrounding rock, beyond 2m from a tunnel face, of the lower bench, the thickness of the lower bench consolidation ring is 7-10m; and the fissure water percolating direction and a lower bench water outlet point are inferred according to the upper bench leakage point fissure and structural plane trend, and lower bench pre-grouting holes are formedaccordingly, and the number of the pre-grouting holes is determined according to the water percolating capacity of the leakage point associated with the upper bench. According to the radial pre-grouting method before excavation of the lower bench of the confined water stratum tunnel, the difficulty of performing radial grouting again after excavation of the lower bench is reduced, the secondary grouting speed is improved, and the grouting effect is improved.

Description

technical field [0001] The invention belongs to the technical field of tunnels and underground engineering, and in particular relates to a radial pre-grouting method before the excavation of lower steps of tunnels in pressurized water formations. Background technique [0002] Radial grouting for tunnels in confined water formations is carried out after excavation of the surrounding rock. When the step method is used for construction, the radial grouting construction of the upper step is completed after the excavation of the upper step, and the leakage point of the upper step surrounding rock is checked. Grouting plugging; after the excavation of the lower bench, radial grouting is performed on the seepage point of the lower bench to block water. Grouting is difficult, and it is difficult to guarantee the grouting effect. Contents of the invention [0003] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a radi...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): E21D9/00
CPCE21D9/001
Inventor 杨文富沙宗天刘凯陈通廖乙宇李强吕德斌彭唯泽
Owner 中铁二局第二工程有限公司
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