Safety early warning method and device for full-section tunneling of tunnel featuring dynamic water and weak surrounding rock

Patent metadata

Field	Value
Publication number	US-11634987-B2
Application number	US-202117478307-A
Country	US
Kind code	B2
Filing date	Sep 17, 2021
Priority date	Oct 13, 2020
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

A safe early warning method and device for full-section tunneling of a tunnel featuring dynamic water and weak surrounding rock, comprising establishing a dynamic coordinate system with an origin thereof moving along a tunnel excavation line, recording the moving distance of the origin, conducting three-dimensional laser scanning with the origin as a center to obtain point cloud data including coordinate data, collecting surrounding rock data; conducting deformation fitting on the point cloud data, calculating a fitting residual error, removing a noisy point, and conducting preprocessing; combining data of preprocessed point cloud, surrounding rock, and the tunnel excavation line to construct a tunnel excavation dynamic model; conducting stress analysis according to the model and determining whether to send out a safety early warning signal. The device comprises a three-dimensional laser scanner, a geological radar device, a displacement module, an industrial computer, a data transmission module, an alarm, and a server.

First claim

What is claimed is:

1. A safety early warning method for full-section tunneling of a tunnel featuring dynamic water and weak surrounding rock, comprising:
S 100 , establishing a dynamic coordinate system, moving an origin of the dynamic coordinate system along a tunnel excavation line as tunnel excavation construction progresses, recording a distance of movement of the origin, conducting a three-dimensional laser scanning in real-time with the origin as a center to obtain point cloud data which include coordinate data, and collecting surrounding rock data in real-time;
S 200 , preprocessing the point cloud data, then conducting deformation fitting, calculating a fitting residual error, and removing a noisy point by taking a set multiple of the fitting residual error deviating from its mean value as a noisy point criterion;
S 300 , combining the preprocessed point cloud data, surrounding rock data, and the tunnel excavation line to construct a tunnel excavation dynamic model; and
S 400 , conducting stress analysis according to the tunnel excavation dynamic model, and determining whether to send out a safety early warning signal according to results of the stress analysis, wherein the stress analysis is conducted as follows:
calculating stress components of a tunnel section in all directions by the following formula:
σ x =2 Re[ f ( x+yi )]−Re[( x−yi ) f ( x+yi )+ w ( x+yi )]

σ y =2 Re[ f ( x+yi )]+Re[( x−yi ) f ( x+yi )+ w ( x+yi )]

σ xy =Im[( x−yi ) f ( x+yi )+ w ( x+yi )]

wherein σ x indicates a stress component in a horizontal direction, σ y indicates a stress component in a vertical direction, σ xy indicates a stress component in a 45-degree inclination direction, Re indicates taking a real part of a complex function, Im indicates taking an imaginary part of the complex function, x indicates the horizontal width of the tunnel, y indicates the vertical height of the tunnel, i represents an imaginary number, and f(x+yi) and w(x+yi) represent a complex stress function:

f
⁡
(

x
+
yi

)

=

1

2
⁢

π
⁡
(

1
+

3
-
γ

1
+
γ

)

⁢

(

F
x

+

iF
y

)

⁢

ln
⁡
(

x
+
yi

)

⁢

w
⁡
(

x
+
yi

)

=

1

2
⁢

π
⁡
(

1
+

3
-
γ

1
+
γ

)

⁢

(

F
x

+

iF
y

)

⁢

ln
⁡
(

x
+
yi

)

,

wherein F x represents a surface force in the horizontal direction, F y indicates a surface force in the vertical direction, and γ represents Poisson's ratio, and
sending out a safety early warning when any of the calculated stress components of the tunnel section in all directions reaches or exceeds a stress threshold of surrounding rock.

2. The safety early warning method for full-section tunneling of the tunnel featuring dynamic water and weak surrounding rock according to claim 1 , wherein in S 100 , the three-dimensional laser scanning is conducted with a three-dimensional laser scanner, the point cloud data obtained by scanning are coordinate data of discrete three-dimensional point sets, the surrounding rock data are collected by a geological radar device, and the surrounding rock data include the dynamic water shape and surrounding rock state of a tunnel face, and the surrounding rock state of a tunnel sidewall, a vault and a bottom face around the origin.

3. The safety early warning method for full-section tunneling of the tunnel featuring dynamic water and weak surrounding rock according to claim 2 , wherein in S 200 , the preprocessing is normalization processing that is conducted as follows:
S 210 , constructing a triangular mesh model according to the coordinate data of the discrete three-dimensional point sets, determining the centroid of point sets in each triangle range in the triangular mesh model, and translating all points in the triangle range in the coordinate system to move the centroid to the origin of coordinates;
S 220 , scaling the coordinate system to a certain size, and selecting an appropriate isotropic scaling factor to scale point cloud coordinates in equal proportion so that the average distance from all points to the origin is 1; and
S 230 , outputting three-dimensional point set data of the processed triangular mesh model.

4. The safety early warning metho

Assignees

• Inst Rock & Soil Mech Cas

Inventors

• Luo Hongming
• Gao Jun
• Chen Shanxiong
• Lin Xiao
• Jiang Lingfa
• Yang Liyun
• Chen Min
• Tang Yu
• Liu Dean
• Wang Sheng
• Peng Xuejun
• Yang Wenguo
• Xie Xiaobo
• Li Xingli
• Wu Dexing
• Xiang Xiaozhen

Classifications

• E21F17/18 Primary

  Special adaptations of signalling or alarm devices (for mine lifts B66B; gas-sensitive devices per se G01N) · CPC title

• G06T17/205

  Re-meshing · CPC title

• E21F17/185 Primary

  Rock-pressure control devices with or without alarm devices; Alarm devices in case of roof subsidence (props with load-measuring devices E21D15/46) · CPC title

• G06T2207/10044

  Radar image · CPC title

• E21D9/003

  Arrangement of measuring or indicating devices for use during driving of tunnels, e.g. for guiding machines · CPC title