Experimental device for longitudinal and transverse physical similarity model of tunnel considering stratum uncertainty

Abstract

The present application belongs to the technical field of tunnel physical similarity model experiments, and proposes a tunnel longitudinal and transverse physical similarity model experimental device that takes into account the uncertainty of the strata, which is applied to the simulation of the influence of the spatial variability of variable strata and soil parameters on the longitudinal and transverse structures of tunnels in the field of geotechnical engineering, including a tunnel excavation simulation module, an external detachable frame, a replaceable model window, a grid partition, and a window blocking device. The device of the present application discretizes the simulated soil units into independent grid units through the longitudinal or transverse partitions of the grid partition, and realizes the simulation of the spatial variability of variable strata and soil parameters by filling different unit soils during the filling process, innovatively realizing the simulation of tunnel excavation and uncertain strata that are densely distributed in a criss-cross pattern, and greatly promoting the study of the stress-deformation characteristics of tunnel structures with complex and criss-cross distribution in uncertain strata.

Description

Technical Field

[0001] The present application belongs to the technical field of tunnel physics similarity model experiments. Background Art

[0002] The rock and soil in nature have experienced a long and complex stress history and the influence of geological factors. The strata have significant uncertainty, which is mainly divided into the variability of strata distribution and the spatial variability of geotechnical parameters. The variability of strata distribution is often also called strata heterogeneity; there are differences in soil properties at different spatial locations, and this difference is called the spatial variability of soil parameters. Strata uncertainty is widely accepted, but the construction and service environment of underground tunnel projects is hidden, the strata around the tunnel are unevenly distributed, and the soil parameters have obvious spatial variability. A large number of studies have shown that strata uncertainty has a significant impact on tunnel structure, and this impact cannot be ignored.

[0003] With the rapid development of underground space in my country, underground space tunnels are crisscrossed. How to better comprehensively consider the uncertainty of the strata and the densely distributed crisscrossed tunnel structure in the model experiment is one of the problems that need to be solved in the current physical similarity model experiment! The existing model experiment equipment in the physical similarity model can usually only simply stratify the strata, and cannot well characterize the spatial variability of variable strata and rock and soil parameters. For this reason, traditional methods often use numerical simulation to characterize the spatial variability of rock and soil parameters. At present, a large number of research methods mainly use random finite element or random finite difference method, which is an analysis framework that combines finite element analysis or finite difference analysis, random field theory and Monte Carlo simulation. However, the accuracy of the calculation results of random finite element or random finite difference cannot be well verified.

[0004] At present, the physical similarity model device usually simplifies the soil into layered soil, which cannot well consider the spatial variability of the parameters of the variable strata and soil. In addition, it lacks the coupling simulation of the longitudinal and transverse structures of the tunnel and the uncertain strata, and cannot well simulate and analyze the increasingly complex tunnel engineering. In summary, due to the more complex structure in the existing tunnel field, the existing tunnel engineering experimental model box generally cannot meet the needs of better considering the spatial variability of the variable strata and soil parameters. Summary of the invention

[0005] The purpose of the present application is to overcome the shortcomings of the prior art. The novel simulation device of the present application is an alternative to the random finite element or random finite difference numerical simulation method, and can also simulate the influence of variable strata and spatial variability of soil parameters on the complex longitudinal and transverse distribution tunnel structure in physical similarity model experiments. The present application can be used to study model experiments related to the analysis of the influence of stress and deformation of the longitudinal and transverse structures of tunnels under uncertain strata. When conducting indoor scaled model experiments, the external detachable frame, tunnel excavation simulation module, replaceable model window, grid partition and window blocking device of the application are assembled into a model box that takes into account variable strata and spatial variability of soil parameters, which is suitable for studying the mechanical response of the longitudinal and transverse structures of tunnels under uncertain strata.

[0006] The technical solution of this application is as follows:

[0007] A tunnel longitudinal and transverse physical similarity model experimental device taking into account stratum uncertainty is used in the simulation of the influence of variable strata and spatial variability of soil parameters on the longitudinal and transverse structure of the tunnel in the field of geotechnical engineering. The device includes a tunnel excavation simulation module, an external detachable frame, a replaceable model window, a grid partition and a window blocking device.

[0008] The tunnel excavation simulation module includes a tunnel model 5 and a liquid sac 6; both ends of the tunnel model 5 are installed on an external detachable frame; the liquid sac 6 wraps the tunnel model 5 all around, and an opening is provided at the bottom of the tunnel model 5, and the drainage port of the liquid sac 6 is inserted through the bottom opening of the tunnel model 5 and extends out from the inner arc surface of the arch bottom of the tunnel model 5.

[0009] The external detachable frame includes a transparent plate 1, anchor bolts 2, and a bottom plate 3; multiple transparent plates 1 are interconnected by anchor bolts 2 and fixed on the bottom plate 3 to form a detachable model box; the transparent plates 1 connected to both ends of the tunnel model are provided with reserved rectangular holes for installing replaceable model windows; and there are reserved grooves 4 on the transparent plates 1 for embedding grid partitions.

[0010] The replaceable model window includes a transparent rectangular plate 7 and an anchoring device 8; the transparent rectangular plate 7 matches the reserved rectangular hole of the transparent plate 1 of the external detachable frame, and is installed on the reserved rectangular hole of the transparent plate 1 through the anchoring device 8; at the same time, the transparent rectangular plate 7 is provided with an opening, and its opening shape and size match the size of the studied tunnel model 5 for fixing the end of the tunnel model 5, facilitating the installation of monitoring equipment inside the tunnel and preventing the soil around the tunnel model 5 from leaking out; the transparent rectangular plate 7 is provided with a reserved groove 4 corresponding to the transparent plate 1 to facilitate the installation of the grid partition.

[0011] The grid partitioning partitions include longitudinal partitions 9 and transverse partitions 10 ; the division of the model box area is achieved by embedding the longitudinal partitions 9 or the transverse partitions 10 into the reserved grooves 4 of the transparent plate 1 .

[0012] The window blocking device includes a transparent shielding plate 11 and an anchoring device 12; the shape of the transparent shielding plate 11 matches the shape of the opening of the transparent rectangular plate 7, and the transparent shielding plate 11 is installed in the holes of the transparent rectangular plate 7 at both ends of the tunnel model 5 not installed through the anchoring device 12.

[0013] Furthermore, the size and quantity of the transparent plates 1 can be customized according to the size of the experimental model box, the buried depth of the tunnel and the thickness requirements of the model stratum.

[0014] Furthermore, the transparent plate 1 can simulate different tunnel burial depths by adjusting the position of the transparent plate 1 with reserved rectangular holes.

[0015] Furthermore, the tunnel model 5 adopts different types of tunnels as needed, and the length of the tunnel model is determined according to the research issues in the longitudinal and transverse directions.

[0016] Furthermore, the liquid-carrying bladder 6 simulates the stratum loss effect of tunnel excavation through the liquid discharge process.

[0017] Furthermore, when the mesh partition is used in the longitudinal and transverse model experiments of the tunnel, the longitudinal partition 9 or the transverse partition 10 is used alone according to the research needs, and the two cannot be used at the same time.

[0018] Furthermore, the window blocking device needs to block the transparent plate 1 in the transverse direction of the tunnel when conducting a longitudinal tunnel experiment, and vice versa.

[0019] Compared with the prior art, this application has the following beneficial effects:

[0020] The present application provides a physical similarity model experimental device that can simultaneously consider the uncertainty of the strata and the vertical and horizontal staggered tunnels. The simulated soil units are discretized into independent grid units through the longitudinal or horizontal partitions of the grid partition partitions. During the filling process, the simulation of variable strata and spatial variability of soil parameters is achieved by filling different unit soils. The present application innovatively realizes the simulation of uncertain strata under the condition of dense distribution of vertical and horizontal staggered tunnels. The application of this device will greatly promote the study of the stress and deformation characteristics of tunnel structures with complex vertical and horizontal staggered distribution in uncertain strata.

[0021] Further improvements include adjusting the number and size of transparent plates in the external detachable frame to achieve simulation of different tunnel depths and soil layers at different depths; and simulation of tunnel models with different similarity ratios, sizes and shapes can be achieved through the openings of the transparent rectangular plates at both ends of the tunnel through customized replaceable model windows. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1This is an overall schematic diagram of the device of this application.

[0023] Figure 2 This is a schematic diagram of the structure breakdown of the device of this application.

[0024] Figure 3 This is a diagram of the tunnel excavation simulation module of the device of this application.

[0025] Figure 4 A schematic diagram of a replaceable model window of the device of the present application.

[0026] Figure 5 This is a schematic diagram of the working of the grid partition and fill of the device of the present application.

[0027] Reference numerals:

[0028] 1-transparent plate, 2-anchor bolts, 3-bottom plate, 4-reserved grooves, 5-tunnel model, 6-liquid capsule, 7-transparent rectangular plate,

[0029] 8-anchoring device, 9-longitudinal partition, 10-transverse partition, 11-transparent shielding plate, 12-anchoring device. DETAILED DESCRIPTION

[0030] The technical solution provided by the present application will be further described below in conjunction with specific embodiments and accompanying drawings. The advantages and features of the present application will become more apparent with the following description.

[0031] The present application is a tunnel longitudinal and transverse physical similarity model experimental device that takes into account the uncertainty of the strata, which is characterized by including an external detachable frame, replaceable model windows, grid partitions and window blocking devices, etc. The purpose is to provide a tunnel physical similarity model experiment that effectively considers the parameter space variability of variable strata and soil, and can be used to study the model experiment related to the analysis of the influence of stress and deformation of the longitudinal and transverse structures of tunnels under uncertain strata. The overall schematic diagram of the device in the application is shown in the figure. Figure 1 shown.

[0032] like Figure 1 , Figure 2 As shown, the tunnel longitudinal and transverse physical similarity model experimental device considering stratum uncertainty includes an external detachable frame, a tunnel excavation simulation module, a replaceable model window, a grid partition and a window blocking device.

[0033] like Figure 1 , Figure 2 , Figure 4As shown, the external detachable frame includes a transparent plate 1, anchor bolts 2, and a base plate 3; multiple transparent plates 1 are assembled into a model box through the anchor bolts 2 and the base plate 3; a rectangular replaceable model window needs to be reserved for the specific transparent plates 1 at the buried depth positions at both ends of the shield tunnel model 5; multiple transparent plates 1 can be arbitrarily combined according to research needs to realize the simulation of changes in different tunnel buried depths; a reserved groove 4 needs to be opened on the inner side of the transparent plate 1 for the installation and sliding of the grid partition.

[0034] like Figure 1 , Figure 2 , Figure 3 As shown, the tunnel excavation simulation module includes a tunnel model 5 and a liquid-carrying sac 6; the tunnel model 5 can adopt tunnel models of various shapes, including circular, horseshoe-shaped, rectangular, etc.; the liquid-carrying sac 6 fully wraps the outer side of the tunnel model 5, and its drainage port extends into the inner side of the tunnel through the lower part of the tunnel model 5, and the stratum loss effect during the tunnel excavation process is simulated by the drainage method.

[0035] like Figure 1 , Figure 2 As shown, the replaceable model window includes a transparent rectangular plate 7 and an anchoring device 8; the transparent rectangular plate 7 is installed on the reserved opening of the specific transparent plate 1 at the buried depth of the tunnel through the anchoring device 8; corresponding openings are made on the transparent rectangular plate 7 according to the shape and size of the tunnel model 5; after the transparent rectangular plate 7 is installed and fixed, it is convenient to install relevant monitoring equipment and prevent the exposure of the model soil.

[0036] like Figure 1 , Figure 2 , Figure 5 As shown, the grid division partition includes a longitudinal partition 9 and a transverse partition 10; according to the longitudinal and transverse problems of the tunnel research, the longitudinal partition 9 or the transverse partition 10 is used separately; the longitudinal partition 9 or the transverse partition 10 can be installed on the reserved groove 4 of the transparent plate 1, and can slide along the track of the reserved groove to realize the division of the soil grid; the order of filling is from left to right and from bottom to top in layers and blocks; the height of one layer of filling is the height of the longitudinal partition 9 or the transverse partition 10, and after filling one layer, the longitudinal partition 9 or the transverse partition 10 is moved upward along the reserved groove 4 and the next layer of model soil is filled in the same order.

[0037] like Figure 1 , Figure 2 As shown, the window blocking device includes a transparent shielding plate 11 and an anchoring device 12. The transparent shielding plate 11 is installed in the hole of the transparent rectangular plate 7 of the replaceable model window through the anchoring device 12; the shape and size of the transparent shielding plate 11 need to match the transparent rectangular plate 7; the transparent rectangular plates 7 at both ends of the tunnel model 5 that are not installed need to be blocked by the transparent shielding plate 11.

[0038] Specifically, a plurality of transparent plates 1 in the external detachable frame are assembled and fixed on the bottom plate 3 by anchor bolts 2 to form the basic outline of the model box; rectangular holes are reserved on the transparent plates 1 at specific positions according to the buried depth of the actual research object tunnel to install replaceable model windows and window blocking devices; at the same time, the transparent plates 1 and the transparent rectangular plates 7 of the replaceable model windows need to have reserved grooves 4 to facilitate the subsequent installation of grid partitions; when installing soil grid partitions, longitudinal partitions 9 or transverse partitions 10 are installed according to the requirements of the experimental design, and the longitudinal partitions 9 or transverse partitions 10 are first installed on the bottom plate 3 along the reserved grooves 4, and different types of model soils are filled in the spaces separated by different partitions according to the experimental needs, and the soil is filled according to certain rules; after the filling is completed, the window blocking devices at the corresponding positions are removed according to the actual unidirectional excavation or bidirectional excavation, and the tunnel excavation simulation is carried out, and the tunnel model 5 and the liquid sac 6 are installed in place according to the experimental design requirements, and the corresponding monitoring equipment is installed, so as to realize the experimental simulation of tunnel excavation in soil with parameter space variability.

[0039] The present application is a tunnel longitudinal and transverse physical similarity model experimental device that takes into account the uncertainty of the strata, and is suitable for exploring the longitudinal and transverse mechanical characteristics of the tunnel structure under uncertain strata conditions. The device can fully consider the variability of the strata in actual engineering and the spatial variability of soil parameters, and can be flexibly adjusted according to the actual tunnel burial depth, size and various similarity ratios required for the research, and has wide applicability.

[0040] The above description is only a description of the preferred embodiments of the present application, and is not intended to limit the scope of the present application. Any changes or modifications made by any person skilled in the art based on the above disclosed technical contents shall be deemed as equivalent effective embodiments and shall fall within the scope of protection of the technical solution of the present application.

Claims

1. The tunnel longitudinal and transverse physical similarity model experimental device considering the uncertainty of the stratum is applied to the simulation of the influence of the spatial variability of variable strata and soil parameters on the longitudinal and transverse structure of the tunnel in the field of geotechnical engineering. It is characterized by: The device includes a tunnel excavation simulation module, an external detachable frame, a replaceable model window, a grid partition and a window blocking device; The tunnel excavation simulation module comprises a tunnel model (5) and a liquid-carrying sac (6); both ends of the tunnel model (5) are mounted on an external detachable frame; the liquid-carrying sac (6) fully wraps the tunnel model (5), and an opening is provided at the bottom of the tunnel model (5); a liquid discharge port of the liquid-carrying sac (6) is inserted through the bottom opening of the tunnel model (5) and extends from the inner arc surface of the arch bottom of the tunnel model (5); The external detachable frame comprises a transparent plate (1), anchor bolts (2), and a bottom plate (3); a plurality of transparent plates (1) are connected to each other by anchor bolts (2), fixed to the bottom plate (3), and assembled into a detachable model box; the transparent plates (1) connected to the tunnel modules are all provided with reserved rectangular holes for installing replaceable model windows; the transparent plates (1) are provided with reserved grooves (4) for embedding grid partition plates; The replaceable model window comprises a transparent rectangular plate (7) and an anchoring device (8); the transparent rectangular plate (7) matches the reserved rectangular hole of the transparent plate (1) of the external detachable frame, and is installed on the reserved rectangular hole of the transparent plate (1) through the anchoring device (8); at the same time, the transparent rectangular plate (7) is provided with an opening, the shape and size of which match the size of the studied tunnel model (5) and are used to fix the end of the tunnel model (5), so as to facilitate the installation of monitoring equipment inside the tunnel and prevent the soil around the tunnel model (5) from leaking out; the transparent rectangular plate (7) is provided with a reserved groove (4) corresponding to the transparent plate (1) so as to facilitate the installation of the grid partition plate; The grid partitioning partitions include longitudinal partitions (9) and transverse partitions (10); the longitudinal partitions (9) or transverse partitions (10) are embedded in the reserved grooves (4) of the transparent plate (1), thereby achieving regional division of the model box; The window blocking device comprises a transparent shielding plate (11) and an anchoring device (12); the shape of the transparent shielding plate (11) matches the shape of the opening of the transparent rectangular plate (7), and the transparent shielding plate (11) is installed in the hole of the transparent rectangular plate (7) where the tunnel model (5) is not installed through the anchoring device (12).

2. The tunnel longitudinal and transverse physical similarity model experimental device considering stratum uncertainty as claimed in claim 1, characterized in that: The size and quantity of the transparent plates (1) are customized according to the size of the experimental model box, the buried depth of the tunnel and the thickness requirements of the model strata.

3. The tunnel longitudinal and transverse physical similarity model experimental device considering stratum uncertainty according to claim 1, characterized in that: The transparent plate (1) can simulate different tunnel burial depths by adjusting the position of the transparent plate with reserved rectangular holes.

4. The tunnel longitudinal and transverse physical similarity model experimental device considering stratum uncertainty according to claim 1, characterized in that: The tunnel model (5) adopts different types of tunnels according to needs, and the length of the tunnel model is determined according to the research problems in the longitudinal and transverse directions.

5. The tunnel longitudinal and transverse physical similarity model experimental device considering stratum uncertainty according to claim 1, characterized in that: The liquid-carrying sac (6) simulates the stratum loss effect of tunnel excavation through the liquid discharge process.

6. The tunnel longitudinal and transverse physical similarity model experimental device considering stratum uncertainty according to claim 1, characterized in that: When the grid partition is used to conduct longitudinal and transverse model experiments in a tunnel, the longitudinal partition (9) or the transverse partition (10) is used alone according to research needs, and the two cannot be used at the same time.

7. The tunnel longitudinal and transverse physical similarity model experimental device considering stratum uncertainty according to claim 1, characterized in that: The window blocking device needs to block the transparent plate in the transverse direction of the tunnel when conducting a tunnel longitudinal experiment, and vice versa.

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