Expansion tunnel surrounding rock stress-strain analysis method

A technology of surrounding rock stress and analysis method, applied in the direction of analyzing materials, using stable tension/pressure testing materials, instruments, etc., can solve the problem of difficult to meet engineering needs, theoretical calculation and analysis can not identify or reflect expansion strain distribution, instability, etc.

Active Publication Date: 2021-07-06
RES INST OF HIGHWAY MINIST OF TRANSPORT
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] In the surrounding rock stability control technology of tunnel engineering, the stress-strain analysis of the surrounding rock is the foundation and basis of the tunnel stability control technology. However, due to the complex properties of the surrounding rock, the stress-strain analysis of the surrounding rock has always been the focus of attention in the field of engineering technology, especially in In the field of expansive rock tunnel engineering, expansive rock tunnels experience expansion deformation and expansion pressure under the action of groundwater, which leads to a high risk of instability for the tunnel lining structure. Since rock expansion is a special mechanical behavior, the relationship between expansion stress and strain is affected by the water content of the rock. Due to the influence and restriction of the rate and stress environment, the existing theoretical calculation and analysis cannot identify or reflect the distribution of expansion strain, and rock expansion can only be reflected in the form of expansion stress, resulting in the theoretical calculation and analysis of the distribution of stress and strain in the surrounding rock of expansive rock tunnels. There is a certain gap in the actual situation, it is difficult to meet the needs of the project

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  • Expansion tunnel surrounding rock stress-strain analysis method
  • Expansion tunnel surrounding rock stress-strain analysis method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0067] Example 1: After the tunnel lining support is completed, the surrounding rock expands under the action of groundwater. The expansion behavior is a limited behavior. The behavior type includes expansion deformation and expansion stress. The expansion behavior type of a certain point in the tunnel surrounding rock is determined by its The relationship between the state of the stress environment and the maximum expansion force of the rock at the time of confinement is determined. The stress field and strain field generated by the expansion of the surrounding rock are based on the existing stress field and displacement field of the surrounding rock of the tunnel. The two do not interfere with each other and are independent of each other. Stability depends on expansion stress and existing ground stress.

[0068] Therefore, the premise of analyzing the stress-strain of the surrounding rock after expansion is to understand the properties of the surrounding rock before expansion...

Embodiment 2

[0177] Embodiment 2: Taking the tunnel surrounding rock of gypsum expansive rock as an example, the excavation surface of the tunnel is circular, and the tunnel radius is r 0 = 8m, the elastic modulus of surrounding rock E = 5GPa, Poisson's ratio μ = 0.3, cohesion C = 600kPa, where the internal friction angle Rock bulk density γ=22kN / m 3 , buried depth h=200m.

[0178] The in-situ stress is the self-weight of the rock mass, the stress in the surrounding rock of the tunnel is regarded as the hydrostatic pressure, and the in-situ stress σ 0 =γh=22×200=4.4MPa, tunnel support force p i =0.2MPa, the maximum expansion force of rock σ pmax =0.8MPa, the maximum confinement expansion strain is 0.01, the total expansion energy N p It is 40MN.m, above are the basic parameters of surrounding rock.

[0179] (1) Judgment of the properties of the surrounding rock after the tunnel lining is completed

[0180] Assuming that the surrounding rock is in an elastic state after the tunnel li...

Embodiment 3

[0222] Embodiment 3: The surrounding rock of the tunnel is gypsum expansive rock, the excavation surface of the tunnel is circular, and the radius of the tunnel is r 0 =8m, the elastic modulus of surrounding rock E=5GPa, Poisson’s ratio μ=0.3, cohesion C=700kPa, and the internal friction angle is

[0223] The tunnel surrounding rock stress is regarded as hydrostatic pressure, and the ground stress σ 0 =γh=2.0MPa, tunnel support force p i =0.3MPa, the maximum expansion force of rock σ pmax =0.9MPa, the maximum confinement expansion strain is 0.09; total expansion energy N p It is 90MN.m, above are the basic parameters of surrounding rock.

[0224] (1) Judgment of the properties of the surrounding rock after the tunnel lining is completed

[0225] Assuming that the surrounding rock is in an elastic state after the tunnel lining is completed, the stresses of the surrounding rock are:

[0226]

[0227]

[0228] According to the Mohrcoullen rock yield criterion, the su...

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Abstract

The invention relates to the technical field of tunnel engineering surrounding rock stability control, in particular to an expansion tunnel surrounding rock stress-strain analysis method which comprises the following steps: (1) judging the properties of surrounding rock before tunnel surrounding rock expansion; (2) dividing the properties of the surrounding rock before expansion into elasticity and shaping, and calculating corresponding parameters according to different properties; and (3) judging the character of the tunnel surrounding rock after expansion, determining the expansion deformation radius, and obtaining the tunnel displacement. Compared with the prior art, the method has the beneficial effects that the method aims to bring the surrounding rock expansion behavior characteristics into the expansive rock tunnel surrounding rock stress-strain analysis, the change of the surrounding rock stress state and the strain state in the tunnel surrounding rock expansion process can be truly reflected, and quantitative calculation of the surrounding rock character change by the expansion stress and the expansion strain can be realized.

Description

technical field [0001] The invention relates to the technical field of stability control of surrounding rock of tunnel engineering, in particular to an analysis method for stress and strain of surrounding rock of an expansive tunnel. Background technique [0002] In the surrounding rock stability control technology of tunnel engineering, the stress-strain analysis of the surrounding rock is the foundation and basis of the tunnel stability control technology. However, due to the complex properties of the surrounding rock, the stress-strain analysis of the surrounding rock has always been the focus of attention in the field of engineering technology, especially in In the field of expansive rock tunnel engineering, expansive rock tunnels experience expansion deformation and expansion pressure under the action of groundwater, which leads to a high risk of instability for the tunnel lining structure. Since rock expansion is a special mechanical behavior, the relationship between e...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N3/08G01D21/02
CPCG01N3/08G01D21/02E21D9/00G01N2203/0075
Inventor 许崇帮高晓静李磊秦幼林
Owner RES INST OF HIGHWAY MINIST OF TRANSPORT
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