A lining support structure suitable for partial excavation of indoor model test tunnels

Abstract

The invention discloses a lining support structure suitable for the partial excavation of an indoor model test tunnel, comprising a large-span thermotropic shape memory polymer material vault template, a thermotropic shape memory polymer material left arch waist template, a thermotropic shape memory polymer material right arch waist template and a thermotropic shape memory polymer material inverted arch template, and both ends of the large-span thermotropic shape memory polymer material vault template are respectively connected with the thermotropic shape memory polymer material left arch waist template and the thermotropic shape memory polymer material right arch waist template through a flange plate between the vault and arch waist templates. The lining support structure suitable for the partial excavation of an indoor model test tunnel of the invention changes the span of the large-span thermotropic shape memory polymer material vault template by adjusting the temperature, which is conducive to the piece-by-piece assembly of the internal lining, making it more in line with the actual construction process, and improving the test accuracy by bolting the annular unit to obtain accurate and reliable experimental results.

Description

Technical Field

[0001] The invention relates to the technical fields of tunnel engineering and geotechnical engineering, and in particular to a lining support structure suitable for partial excavation of an indoor model test tunnel. Background Art

[0002] In recent years, with the rapid development of science and technology and the national economy, the number of highway and railway tunnels has shown a sharp increase, and the types of tunnels and construction methods have become more and more diverse. The safety and economy of tunnel construction have attracted more attention and attention. In order to effectively evaluate the safety and economy of the construction process, it is necessary to simulate and analyze the tunnel construction process through various means. Among them, indoor model tests have become a popular means of studying and analyzing tunnel construction problems due to their low cost, obvious effect, and simple operation. In the actual construction process, tunnel excavation and support is a dynamic nonlinear process. If the simulation of the excavation and support process is significantly different from the actual process, the test results obtained by the indoor model test will be significantly different from the true values ​​obtained in the actual construction process.

[0003] Indoor tunnel model tests mainly use two methods to achieve tunnel excavation and support: one is the pre-embedded method, that is, the prefabricated steel or gypsum lining and the internal filling blocks of the lining are embedded in the model in advance during the model casting process, and the tunnel excavation simulation is achieved by taking out the internal filling blocks; the other is the assembled method, that is, the soil is excavated after the model casting is completed, and then the prefabricated lining blocks are installed. Method 1 is simple to operate, no soil falls during the unloading process, and since there is no over-excavation or under-excavation, no cavity disease occurs on the back of the lining. However, the simulated excavation process is contrary to the actual situation, and the unloading effect may not affect the test due to the excessive overall stiffness of the lining. Method 2 is consistent with the actual construction process, but it also has certain defects, such as how to pass the large-span arch template with an earth pressure box or strain gauge on the top through the previous ring to complete the lining when assembling the internal lining. Summary of the invention

[0004] The purpose of the present invention is to provide a lining support structure suitable for the partial excavation of an indoor model test tunnel. By adjusting the temperature, the span of a large-span thermotropic shape memory polymer arch template can be changed, which is conducive to the piece-by-piece assembly of the internal lining, making it more in line with the actual construction process. The test accuracy is improved by tightening the annular unit with bolts, and accurate and reliable experimental results can be obtained, which can solve the problems in the prior art.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a lining support structure suitable for the partial excavation of an indoor model test tunnel, comprising a large-span thermotropic shape memory polymer material vault template, a thermotropic shape memory polymer material left arch waist template, a thermotropic shape memory polymer material right arch waist template and a thermotropic shape memory polymer material inverted arch template, wherein both ends of the large-span thermotropic shape memory polymer material vault template are respectively connected with the thermotropic shape memory polymer material left arch waist template and the thermotropic shape memory polymer material right arch waist template by bolts through a flange plate between the vault and arch waist templates, and the thermotropic shape memory polymer material left arch waist template and the thermotropic shape memory polymer material inverted arch template are respectively connected with the thermotropic shape memory polymer material left arch waist template and the thermotropic shape memory polymer material inverted arch template by bolts. One end of the right arch waist formwork is connected to the two ends of the thermotropic shape memory polymer material inverted arch formwork by bolts through the flange between the arch waist and inverted arch formwork, the adjacent large-span thermotropic shape memory polymer material arch crown formworks are connected by bolts through the flange at the arch crown between the front and rear rings and the flange at the arch shoulder between the front and rear rings, the adjacent left arch waist formworks of the thermotropic shape memory polymer material are connected by bolts through the flange at the arch waist between the front and rear rings, the adjacent right arch waist formworks of the thermotropic shape memory polymer material are also connected by bolts through the flange at the arch waist between the front and rear rings, and the adjacent thermotropic shape memory polymer material inverted arch formworks are connected by bolts through the flange at the invert between the front and rear rings.

[0006] Preferably, the flanges between the vault and waist templates, the flanges at the vault between the front and rear rings, and the flanges at the shoulders between the front and rear rings are all welded to the large-span thermotropic shape memory polymer vault templates.

[0007] Preferably, the flanges between the arch crown and waist formworks, the flanges between the waist and inverted arch formworks, and the flanges at the waist between the front and rear rings are all welded to the left waist formwork made of thermotropic shape memory polymer material and the right waist formwork made of thermotropic shape memory polymer material.

[0008] Preferably, the flange between the arch waist inverted arch formwork and the flange at the inverted arch between the front and rear rings are welded to the inverted arch formwork made of thermotropic shape memory polymer material.

[0009] Compared with the prior art, the present invention has the following beneficial effects:

[0010] The lining support structure of the present invention is suitable for the partial excavation of an indoor model test tunnel. By adjusting the temperature, the span of a large-span thermotropic shape memory polymer arch template is changed, which is beneficial to the piece-by-piece assembly of the internal lining, making it more in line with the actual construction process. The test accuracy is improved by tightening the annular unit with bolts, and accurate and reliable experimental results can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1It is a schematic plan view of the tunnel lining of the present invention in an initial state;

[0012] Figure 2 It is a schematic diagram of the structure of the combination of the present invention;

[0013] Figure 3 It is a schematic diagram of the structure of combination 2 of the present invention;

[0014] Figure 4 It is a schematic diagram of the structure of combination four of the present invention;

[0015] Figure 5 It is a schematic diagram of a temporary deformed M-shaped structure of the combination of the present invention;

[0016] Figure 6 It is a schematic diagram of a temporary deformed inverted U-shaped structure of the combination of the present invention;

[0017] Figure 7 It is a schematic diagram of the combined four-brick temporary deformed U-shaped structure of the present invention.

[0018] In the figure: 1. Large-span thermotropic shape memory polymer vault formwork; 2. Left waist formwork made of thermotropic shape memory polymer; 3. Right waist formwork made of thermotropic shape memory polymer; 4. Invert formwork made of thermotropic shape memory polymer; 5. Flange between vault and waist formworks; 6. Flange between waist and invert formworks; 7. Flange at vault between front and rear rings; 8. Flange at shoulder between front and rear rings; 9. Flange at waist between front and rear rings; 10. Flange at invert between front and rear rings. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] See also Figure 1-7A lining support structure suitable for partial excavation of an indoor model test tunnel comprises a large-span thermotropic shape memory polymer material arch template 1, a thermotropic shape memory polymer material left arch waist template 2, a thermotropic shape memory polymer material right arch waist template 3 and a thermotropic shape memory polymer material inverted arch template 4. The large-span thermotropic shape memory polymer material arch template 1 can reduce its radial span through heating, load and cooling treatment to ensure that it can pass through the closed previous ring lining. When the top of the large-span thermotropic shape memory polymer material arch template 1 contacts the surrounding rock at the top of the next ring after deformation, the temperature is increased again to restore the large-span thermotropic shape memory polymer material arch template 1 to the initial stage, and the space between the two rings is tightened. The flange 7 at the arch between the front and rear rings and the flange 8 at the arch shoulder between the front and rear rings complete the partial assembly of the lining and the annular closure. The thermotropic shape memory polymer material has good shape memory ability. In the initial state, the material can change its shape under high temperature and external force. After cooling, the temporary shape will be retained. When the temperature is raised again, the temporary shape will be perfectly restored to the initial state in a short time. Both ends of the large-span thermotropic shape memory polymer material arch template 1 are respectively connected with the thermotropic shape memory polymer material left arch waist template 2 and the thermotropic shape memory polymer material right arch waist template 3 by bolts through the flange 5 between the arch arch waist template. The thermotropic shape memory polymer material left arch waist template 2 and the thermotropic shape memory polymer material right arch waist template One end of the polymer material right arch waist formwork 3 is respectively connected to the two ends of the thermotropic shape memory polymer material arch back formwork 4 by bolts through the flange plate 6 between the arch waist and arch back formworks, and the adjacent large-span thermotropic shape memory polymer material arch top formworks 1 are connected by bolts through the flange plate 7 at the arch between the front and rear rings and the flange plate 8 at the arch shoulder between the front and rear rings. The flange plate 5 between the arch waist formworks, the flange plate 7 at the arch between the front and rear rings, and the flange plate 8 at the arch shoulder between the front and rear rings are all welded to the large-span thermotropic shape memory polymer material arch top formwork 1. The adjacent thermotropic shape memory polymer material left arch waist formworks 2 are connected by bolts through the flange plate 9 at the arch waist between the front and rear rings. The adjacent thermotropic shape memory polymer material right arch waist formworks 3 is also connected by bolts through the flange 9 at the waist between the front and rear rings, the flange 5 between the arch top waist template, the flange 6 between the waist inverted arch template and the flange 9 at the waist between the front and rear rings are all welded to the left waist template 2 of the thermotropic shape memory polymer material and the right waist template 3 of the thermotropic shape memory polymer material, the adjacent thermotropic shape memory polymer material inverted arch templates 4 are connected by bolts through the flange 10 at the inverted arch between the front and rear rings, the flange 6 between the waist inverted arch template and the flange 10 at the inverted arch between the front and rear rings are all welded to the thermotropic shape memory polymer material inverted arch template 4, different construction methods are selected, and the required deformed template shape is also different, but generally inverted U-shaped, M-shaped or U-shaped. Under normal circumstances,The largest independent formwork in the whole unit cannot pass through the internal space of the completely closed previous ring lining formwork.

[0021] Assembly principle of lining support structure: The flange 5 between the large-span thermo-shaped memory polymer material vault formwork 1 and the vault waist formwork, the flange 7 between the front and rear rings at the vault, and the flange 8 between the front and rear rings at the shoulder are welded to form combination 1, and the flange 5 between the thermo-shaped memory polymer material left waist formwork 2 and the vault waist formwork, the flange 6 between the waist and back arch formwork, and the flange 9 between the front and rear rings at the waist are welded to form combination 2. In the initial state, the diameter of combination 1 and combination 2 under deformation temperature and external force conditions is The span is reduced, and then it is placed in a freezer with a temperature of 1°C to cool, and a deformed template is obtained. The flange 5 between the right arch waist template 3 of the thermo-induced shape memory polymer material and the arch top arch waist template, the flange 6 between the arch waist and inverted arch template, and the flange 9 at the arch waist between the front and rear rings are welded to form a combination three, and the flange 6 between the thermo-induced shape memory polymer material inverted arch template 4 and the flange 10 between the arch waist and inverted arch template and the front and rear rings are welded to form a combination four. The combination one, combination two, combination three and combination four are welded through the arch The bolts on the flange 5 between the top arch waist template and the flange 6 between the arch waist and inverted arch template are connected to form a closed integral unit. By tightening the bolts on the flange 7 at the arch top between the front and rear rings, the flange 8 at the arch shoulder between the front and rear rings, the flange 9 at the arch waist between the front and rear rings and the flange 10 at the inverted arch between the front and rear rings, the front and rear ring lining templates are connected tightly to complete the tight closure between the rings. When the top of the combination contacts the exposed top surrounding rock of the next ring after deformation, a piece of asbestos is placed near the lining of the previous ring in the combination, and then When the temperature is raised for the second time, combination one will return to the initial stage, that is, return to the original design form of the lining, and tighten the flange between the front and rear rings to complete the partial assembly of the top lining and the annular closure state; when the outer surface is deformed with a layer of asbestos, when the bottom of combination four contacts the exposed bottom surrounding rock of the rear ring, the temperature is raised again, combination four will return to the initial stage, that is, return to the original design form of the lining, and tighten the flange between the front and rear rings to complete the partial assembly of the bottom lining and the annular closure state.

[0022] Taking the step excavation method as an example, two rings of excavation will be carried out in this partial excavation example, and the tunnel is not transparent after the excavation is completed. The second ring of large-span thermotropic shape memory polymer material arch template 1 is prepared: the electric heating resistance wire with a temperature reaching the deformation temperature of the thermotropic shape memory polymer material is placed near the combination one, and the material is applied with a jack. Considering the limited height and span after the upper step excavation, the large-span thermotropic shape memory polymer material arch template 1 is fixed into an M shape, cooled with 1°C ice water, wiped dry, and a temporary M-shaped template is obtained. The second ring of thermotropic shape memory polymer material inverted arch template 4 is prepared: the method is the same as above, but considering the installation of the inverted arch, the soil inside the ring All the excavations have been completed, so the thermotropic shape memory polymer material arch template 4 can be temporarily prepared into a U shape, and a layer of asbestos can be wrapped on its outer surface. The first ring soil excavation support simulation: first, the first ring upper step is excavated. After the tunnel is excavated to the preset size, the first ring initial state combination 1 is installed in the hole, and then the first ring lower step soil is excavated. Similarly, after the hole is excavated to the preset limit, the initial state combination 2, initial state combination 3, and initial state combination 4 are installed in the tunnel, and the various parts are closed by adjusting bolts to form a closed and complete first ring lining, completing the first ring excavation support simulation, the second ring soil upper step excavation support template Simulation: First, excavate the soil within the boundary range of the upper step of the second ring. After the excavation is completed, send the temporary M-shaped template through the inside of the first ring lining to the upper step of the second ring, and place a piece of asbestos near the lining of the previous ring in combination one. Then use the electric heating resistance wire to increase the temperature of the temporary M-shaped structure to restore the structure to its initial state, and then use the temporary support rod to fix combination one. Finally, tighten the bolts of the flange 7 at the arch crown between the front and rear rings and the flange 8 at the arch shoulder between the front and rear rings to achieve the purpose of closing the ring seam. Simulation of excavation support for the lower step of the second ring soil: excavate the lower step. After the excavation of the soil on both sides of the lower step is completed, send combination two and combination three through the first ring to the inside of the second ring. , install and fix combination 2 and combination 3 in sequence, remove temporary support rods, remove all remaining soil, and use the same method to send combination 4 with a layer of asbestos on the outer surface to the second ring space, and then use the electric heating resistance wire inserted into the gap between combination 4 and the asbestos to temporarily increase the temperature of the U-shaped structure, so that combination 4 returns to its initial state, and then tighten the bolts on flange 5 between the arch crown and waist formwork, flange 6 between the arch waist and inverted arch formwork, flange 7 at the arch between the front and rear rings, flange 8 at the arch shoulder between the front and rear rings, flange 9 at the arch waist between the front and rear rings and flange 10 at the inverted arch between the front and rear rings, so as to achieve the purpose of closing the rings and annular joints. At this point, the tunnel section excavation and support are completed.

[0023] In summary, the lining support structure of the present invention, which is suitable for the partial excavation of the indoor model test tunnel, changes the span of the large-span thermotropic shape memory polymer arch template 1 by adjusting the temperature, which is beneficial to the piece-by-piece assembly of the internal lining, making it more in line with the actual construction process, and improves the test accuracy by bolting the annular unit, so that accurate and reliable experimental results can be obtained.

[0024] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0025] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A lining support structure suitable for partial excavation of an indoor model test tunnel, comprising a large-span thermotropic shape memory polymer material vault formwork (1), a thermotropic shape memory polymer material left arch formwork (2), a thermotropic shape memory polymer material right arch formwork (3) and a thermotropic shape memory polymer material invert arch formwork (4), characterized in that: Both ends of the large-span thermotropic shape memory polymer arch template (1) are respectively connected to the left arch template (2) of the thermotropic shape memory polymer material and the right arch template (3) of the thermotropic shape memory polymer material by bolts through the flange plate (5) between the arch templates. One end of the left arch template (2) of the thermotropic shape memory polymer material and the right arch template (3) of the thermotropic shape memory polymer material are respectively connected to the two ends of the thermotropic shape memory polymer material inverted arch template (4) by bolts through the flange plate (6) between the arch templates. The memory polymer material arch templates (1) are connected by bolts through the arch flanges (7) between the front and rear rings and the shoulder flanges (8) between the front and rear rings; the adjacent thermotropic shape memory polymer material left arch waist templates (2) are connected by bolts through the arch waist flanges (9) between the front and rear rings; the adjacent thermotropic shape memory polymer material right arch waist templates (3) are also connected by bolts through the arch waist flanges (9) between the front and rear rings; and the adjacent thermotropic shape memory polymer material inverted arch templates (4) are connected by bolts through the inverted arch flanges (10) between the front and rear rings; The flanges (5) between the arch and waist templates, the flanges (7) between the front and rear rings at the arch, and the flanges (8) between the front and rear rings at the shoulder are all welded to the large-span thermotropic shape memory polymer arch template (1); The flanges (5) between the arch crown and waist templates, the flanges (6) between the waist and inverted arch templates, and the flanges (9) between the front and rear rings at the waist are all welded to the left waist template (2) made of thermotropic shape memory polymer material and the right waist template (3) made of thermotropic shape memory polymer material; The flange plate (6) between the arch waist inverted arch templates and the flange plate (10) at the inverted arch between the front and rear rings are welded to the inverted arch template (4) made of thermotropic shape memory polymer material; The large-span thermotropic shape memory polymer material vault template (1) can reduce its radial span through heating, loading and cooling treatment to ensure that it can pass through the closed previous ring lining. When the top of the large-span thermotropic shape memory polymer material vault template (1) contacts the surrounding rock at the top of the next ring after deformation, the temperature is raised again to restore the large-span thermotropic shape memory polymer material vault template (1) to the initial stage, and the flanges (7) at the vault between the front and rear rings and the flanges (8) at the spandrel between the front and rear rings are tightened, thus completing the partial assembly of the lining and the annular closure. The assembly principle of the lining support structure: A large-span thermotropic shape memory polymer material vault template (1) is welded to a flange (5) between the vault and waist template, a flange (7) at the vault between the front and rear rings, and a flange 8 at the shoulder between the front and rear rings to form a combination; The left arch waist template (2) made of thermotropic shape memory polymer material is welded to the flange plate (5) between the arch top arch waist template, the flange plate (6) between the arch waist and inverted arch templates, and the flange plate (9) at the arch waist between the front and rear rings to form a second combination; In the initial state, the radial span of combination 1 and combination 2 is reduced under the deformation temperature and external force conditions, and then they are placed in a refrigerator at a temperature of 1°C for cooling to obtain a deformed template, and the right arch waist template (3) of the thermotropic shape memory polymer material is welded with the flange plate (5) between the arch top and arch waist template, the flange plate (6) between the arch waist and inverted arch templates, and the flange plate (9) at the arch waist between the front and rear rings to form combination 3; The thermo-induced shape memory polymer material inverted arch template (4) is welded to the flange plate (6) between the arch waist inverted arch template and the flange plate (10) at the inverted arch between the front and rear rings to form a fourth assembly; The combination 1, combination 2, combination 3 and combination 4 are connected by bolts on the flange plate (5) between the arch crown and waist templates and the flange plate (6) between the arch waist and inverted arch templates to form a closed integral unit, and the front and rear ring lining templates are tightly connected by tightening the bolts on the flange plate (7) at the arch crown between the front and rear rings, the flange plate (8) at the arch shoulder between the front and rear rings, the flange plate (9) at the arch waist between the front and rear rings, and the flange plate (10) at the inverted arch between the front and rear rings to complete the tight closure between the rings; After deformation, when the top of the first combination contacts the exposed top surrounding rock of the next ring, place a piece of asbestos near the lining of the previous ring of the first combination, and raise the temperature again. The first combination will return to the initial stage, that is, return to the original design form of the lining, and tighten the flange between the front and rear rings to complete the partial assembly of the top lining and the annular closure state; When the outer surface is deformed with a layer of asbestos, and the bottom of the combination four contacts the exposed bottom surrounding rock of the next ring, the temperature is raised again, and the combination four will return to the initial stage, that is, return to the original design form of the lining, and tighten the flange between the front and rear rings to complete the segmented assembly of the bottom lining and the annular closure state.

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