Tunnel model test supporting structure wall surface full-field deformation test method

Abstract

The invention discloses a tunnel model test supporting structure wall surface full-field deformation test method, and relates to the technical field of tunnel similar model test design, and the method comprises the following steps: S1, building a tunnel model, filling the model with a soil body, and installing a supporting structure; s2, deformation measurement is carried out, the tunnel model is excavated, and a tunnel supporting structure wall surface image containing distance information is shot; and S3, deformation analysis: splicing the images into a ring for data analysis. According to the tunnel model test supporting structure wall surface full-field deformation testing method, three parts of tunnel model, deformation measurement and deformation analysis are adopted, non-contact high-density deformation measurement of a tunnel model supporting structure can be achieved, full-field strain, displacement, deformation, stress and the like of the supporting structure can be analyzed, and the testing accuracy is improved. The problems of complex operation, large interference and the like of tunnel model test supporting structure measurement are solved, and the method has the advantages of simplicity in operation and rapidness in measurement under the condition of meeting measurement requirements.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel similarity model test design, in particular to a tunnel model test support structure wall full-field deformation test method. Background Art

[0002] In order to study the deformation and stress of the surrounding rock and supporting structure after tunnel excavation, similar model test methods are often used for exploration. In the test, multi-point displacement meters, strain gauges and optical fibers are laid out to measure the strain of the supporting structure. These methods are all contact measurements, and the measuring elements need to be buried inside the structure. The measuring elements themselves will affect the redistribution of stress and deformation of the tunnel surrounding rock to varying degrees, thereby affecting the measurement accuracy. Furthermore, in order to obtain more continuous measurement results, the density of the measurement elements is often large, which will inevitably increase the impact on the measurement accuracy. Therefore, non-contact high-density full-field deformation measurement of tunnel support structures is particularly important, and there is currently no suitable test method. Summary of the invention

[0003] The purpose of the present invention is to provide a tunnel model test support structure wall full-field deformation testing method, which can realize non-contact high-density deformation measurement of the tunnel model support structure and analyze the full-field strain, displacement, deformation, stress, etc. of the support structure.

[0004] To achieve the above object, the present invention provides a tunnel model test support structure wall full-field deformation test method, comprising the following steps:

[0005] S1. Establish a tunnel model, fill the model with soil and install the supporting structure;

[0006] S2, deformation measurement, excavating the tunnel model and taking images of the tunnel support structure wall containing distance information;

[0007] S3, deformation analysis, data analysis of images spliced ​​into rings.

[0008] Preferably, S2 includes the following steps:

[0009] S21, excavating the first footage of the tunnel, taking a wall image of the tunnel support structure containing distance information for this footage;

[0010] S22, excavating the next footage of the tunnel, and photographing the wall surface images of the tunnel support structure containing distance information of all the footages that have been excavated;

[0011] S23, repeat S21-S22 until the tunnel excavation is completed;

[0012] S24, the single footage images are stitched into a ring, and the images in the rings of each footage are stitched into a whole;

[0013] S25, obtaining a deformation cloud map of the wall surface of all supporting structures of the excavated part of each footage;

[0014] S26, after the excavation is completed, a first level load is applied to the top of the soil in the model box, and an image of the wall surface of the entire tunnel support structure containing distance information is taken;

[0015] S27, applying the next level of load on the top of the model box soil, and taking an image of the wall surface of the entire tunnel support structure containing distance information;

[0016] S28, stitching the entire tunnel support structure wall image containing distance information;

[0017] S29, repeat S26-S28 until the last level of load application is completed;

[0018] S210. Obtain deformation cloud diagrams of the tunnel support structure wall under different levels of loads.

[0019] Preferably, in S1, the opening of the model box is sealed.

[0020] Preferably, after excavation in S2 is completed, a load is applied to the top of the soil in the model box to measure the deformation of the supported tunnel under different vertical loads.

[0021] Preferably, the analysis cloud diagram in S3 includes deformation, stress and strain analysis.

[0022] Therefore, the present invention adopts the above-mentioned tunnel model test support structure wall full-field deformation testing method, which can realize non-contact high-density deformation measurement of the tunnel model support structure, and can analyze the full-field strain, displacement, deformation, stress, etc. of the support structure, overcoming the difficult problems of complex measurement operation and large interference of the tunnel model test support structure. Under the condition of meeting the measurement requirements, it has the advantages of simple operation and fast measurement.

[0023] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a tunnel model diagram of the present invention;

[0025] Figure 2 is a cross-sectional view of a tunnel model of the present invention;

[0026] Figure 3 is an image stitching flow chart of an embodiment of the present invention;

[0027] Figure 4 It is a schematic diagram of a specific embodiment of the present invention;

[0028] Reference numerals

[0029] 1. Soil; 2. Model box; 3. Tunnel support structure; 4. Support structure for the first footage; 5. Support structure for the second footage; 6. Support structure for the last footage; 7. Wall image containing distance information in one area of ​​a single footage; 8. Illustration of wall images containing distance information in all areas of a single footage; 9. Single footage images stitched into a ring; 10. Stitching combination of two footage images; 11. Stitching combination of three footage images; 12. Stitching combination of wall images of the entire tunnel support structure. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0031] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0032] Example

[0033] See also Figure 1-4 The present invention provides a tunnel model test support structure wall full-field deformation test method, comprising the following steps:

[0034] S1. Establish a tunnel model, including a model box 2, soil and a support structure, fill the model with soil 1 and install a tunnel support structure 3. The opening of the model box 2 is sealed with a rubber pad and a sealing ring to prevent leakage of soil samples during the test.

[0035] S2. Deformation measurement, including taking images containing distance information. The images containing distance information can be taken using equipment based on binocular vision distance measurement technology, such as digital image correlation (DIC) equipment.

[0036] S21, excavating the first footage of the tunnel, forming the first footage support structure 4, and photographing the wall surface image of the tunnel support structure containing distance information of this footage;

[0037] S22, excavating the next footage of the tunnel to form a second footage support structure 5, and photographing the wall images of the tunnel support structure containing distance information of all the footages that have been excavated;

[0038] S23, repeat S21-S22 until the tunnel excavation is completed, forming the last advance support structure 6;

[0039] S24, the single footage images are stitched into a ring, and the images in the rings of each footage are stitched into a whole;

[0040] S25, obtaining a deformation cloud map of the wall surface of all supporting structures of the excavated part of each footage;

[0041] S26, after the excavation is completed, a first level load is applied to the top of the soil in the model box, and an image of the wall surface of the entire tunnel support structure containing distance information is taken;

[0042] S27, applying the next level of load on the top of the model box soil, and taking an image of the wall surface of the entire tunnel support structure containing distance information;

[0043] S28, stitching the entire tunnel support structure wall image containing distance information;

[0044] S29, repeat S26-S28 until the last level of load application is completed;

[0045] S210. Obtain deformation cloud diagrams of the tunnel support structure wall under different levels of loads.

[0046] Steps S21-25 measure the deformation caused by tunnel excavation, and steps S26-210 measure the deformation of the supported tunnel under different vertical loads.

[0047] S3, deformation analysis, data analysis is performed on the images spliced ​​into a ring. The analyzed image is a complete ring, and the cloud map structure is analyzed, including deformation, stress, strain analysis, etc.

[0048] like Figure 4 As shown in the schematic diagram of the specific embodiment, after S21 is implemented, a deformation cloud diagram of a partial area of ​​the single-foot support structure can be obtained, such as Figure 3 After S22-S23 are implemented, a deformation cloud map showing the splicing of wall images containing distance information in all regions of the single footage 8 can be obtained, such as Figure 3 The single footage images in the figure are stitched into ring 9; after S24-S25 are implemented, the deformation cloud map of the wall surface of all supporting structures in the excavated part of each footage can be obtained, such as Figure 3The two-footage image mosaic combination 10, the three-footage image mosaic combination 11, and the entire tunnel support structure wall image mosaic combination 12, that is, the full-field deformation of the tunnel support structure under the excavation unloading action of each excavation step; when the excavation is completed and the loading continues, after implementing S26-S210, the deformation cloud map of the tunnel support structure wall under different levels of load can be obtained, that is, the deformation response of the tunnel support structure under different ground stress levels.

[0049] Therefore, the present invention adopts the above-mentioned tunnel model test support structure wall full-field deformation test method, which consists of three parts: tunnel model, deformation measurement and deformation analysis. It can realize non-contact high-density deformation measurement of the tunnel model support structure, and can analyze the full-field strain, displacement, deformation, stress, etc. of the support structure. It overcomes the difficult problems of complex measurement operation and large interference of the tunnel model test support structure. Under the condition of meeting the measurement requirements, it has the advantages of simple operation and fast measurement.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A tunnel model test support structure wall full-field deformation test method, characterized in that: The following steps are involved: S1. Establish a tunnel model, fill the model with soil and install the supporting structure; S2, deformation measurement, excavating the tunnel model and taking images of the tunnel support structure wall containing distance information; S3, deformation analysis, data analysis of images spliced ​​into rings.

2. A tunnel model test support structure wall full-field deformation test method according to claim 1, characterized in that: S2 includes the following steps: S21, excavating the first footage of the tunnel, taking an image of the wall surface of the tunnel support structure containing distance information for this footage; S22, excavating the next footage of the tunnel, and photographing the wall surface images of the tunnel support structure containing distance information of all the footages that have been excavated; S23, repeat S21-S22 until the tunnel excavation is completed; S24, the single footage images are stitched into a ring, and the images in the rings of each footage are stitched into a whole; S25, obtaining a deformation cloud map of the wall surface of all supporting structures of the excavated part of each footage; S26, after the excavation is completed, a first level load is applied to the top of the soil in the model box, and an image of the wall surface of the entire tunnel support structure containing distance information is taken; S27, applying the next level of load on the top of the model box soil, and taking an image of the wall surface of the entire tunnel support structure containing distance information; S28, stitching the entire tunnel support structure wall image containing distance information; S29, repeat S26-S28 until the last level of load application is completed; S210. Obtain deformation cloud diagrams of the tunnel support structure wall under different levels of loads.

3. A tunnel model test support structure wall full-field deformation test method according to claim 2, characterized in that: In S1, the opening of the model box is sealed.

4. A tunnel model test support structure wall full-field deformation test method according to claim 3, characterized in that: After the excavation in S2 was completed, a load was applied to the top of the soil in the model box, and the deformation of the supported tunnel under different vertical loads was measured.

5. A tunnel model test support structure wall full-field deformation test method according to claim 4, characterized in that: The analysis cloud diagram in S3 includes deformation, stress and strain analysis.

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