Autonomous regulation and control model test device and test method for shield tunnel deformation

Abstract

The invention discloses an autonomous regulation and control model test device and method for shield tunnel deformation, and the device mainly comprises a model test box structure, a tunnel active internal pressure regulation and control composite reinforcement system and a tunnel active external pressure regulation and control system. The tunnel bearing capacity is improved by adopting a method of recovering partial transverse ellipse change by active internal pressure and synchronously sticking aramid fiber cloth on an interface according to the displacement adjustment recovery condition of the ellipse change tunnel and the change condition of a soil body around the tunnel, and the soil body is controlled transversely or longitudinally, so that active adjustment of deformation or settlement of the shield tunnel is realized. The shield tunnel and soil body self-regulation and control system has the advantages that the problem of fast and efficient reinforcement of the shield tunnel is effectively solved, a complete shield tunnel and soil body self-regulation and control system is formed, the system is specially used for fast and accurate intervention aiming at potential structure risks caused by tunnel deformation, and the external load resisting capacity of the shield tunnel is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel engineering in rock and soil and underground engineering, and in particular relates to an autonomous control model test device and a test method for shield tunnel deformation. Background Art

[0002] Shield tunnel technology is widely used in urban rail transit construction due to its high mechanization level and safety construction advantages; however, shield tunnels that have been in operation for many years may have problems such as water leakage, cracks and large deformation of the lining structure. At present, internal reinforcement is mainly carried out by steel plates or external reinforcement is carried out by grouting the outside of the tunnel. Although the above methods are effective, they are mostly passive reinforcement. Therefore, exploring the active control technology of tunnels has become a new method with great potential in the field of tunnel maintenance and reinforcement.

[0003] In response to various structural defects that occur during the construction and operation of shield tunnels, research usually focuses on passive repair and reinforcement strategies. The elliptical deformation that has occurred cannot be changed. In order to solve this problem more effectively, this study adopts a comprehensive autonomous adjustment and control strategy, focusing on regulating the deformation of the shield tunnel in different directions, fundamentally improving the structural stability and extending its service life.

[0004] At present, for the shield tunnel model test, the "A Modular Soil Box for Subway Similarity Simulation Test" with application number 201910558112.1 is designed with four side box panels using steel plates as baffles, and observation windows are opened on the side box panels. However, the side box panels are not transparent as a whole, which is not intuitive and is not conducive to observing and recording changes in the model structure and its surrounding soil. In the "A Bag-Type Grouting Anchor" with application number 202311106365.8, the bag is mainly used for grouting to achieve different anchoring effects, but the airbag in this patent can increase or decrease its volume for tunnel deformation recovery, and at the same time play a certain buffering role; the "A Multidimensional Active Control Method for Regulating Tunnel Vector Deformation by Flexible Body Expansion" with application number 202110544145.8 regulates tunnel deformation by flexible body expansion, but when it acts on the bottom of the tunnel, it is easy to cause the arch bottom to rise while the arch top does not move; but when this patent acts on the arch bottom, there is an internal support system inside to ensure that the tunnel does not deform, thereby achieving the effect of overall lifting; the "A Model Test Device and Test Method for Shield Tunnel Lining" with application number 202210817169.0 uses a repair and reinforcement method that mainly uses manual alternate gluing of aramid fiber cloth to the inner surface of the segment, but fails to use an internal pressure device to lift the aramid fiber cloth until it solidifies, making the fiber cloth gluing effect more firm.

[0005] However, the existing shield tunnel reinforcement test devices are unclear in terms of the tunnel repair mechanism, and there is a lack of clear understanding of the soil change process. These devices have not been able to effectively adapt to the skylight time constraints of shield tunnels that require rapid repair. Therefore, it is urgent to develop a highly visualized shield tunnel active control model test device for in-depth experimental research. This device will enable researchers to observe and analyze the behavior and response of the tunnel under various stress conditions in real time, thereby providing a theoretical basis and practical guidance for the rapid repair of shield tunnels. Summary of the invention

[0006] The purpose of the present invention is to provide an autonomous control model test device and a test method for shield tunnel deformation in response to the shortcomings of passive repair technology. The device can comprehensively consider the active and appropriate repair and reinforcement of shield segment deformation, active compensation measures for soil loss, etc., and has significant scientific research significance for improving the test level in this field.

[0007] The technical solution of the present invention is as follows: a shield tunnel deformation self-regulating model test device, including a model test box structure, the model test box structure is an outer frame mainly composed of channel steel and corner columns, and the interior is surrounded by organic glass panels to form a rectangular structure; it also includes a tunnel active internal pressure regulation composite reinforcement system and a tunnel active external pressure regulation system;

[0008] The tunnel active internal pressure control composite reinforcement system comprises an arc-shaped base frame, a jack, an arc-shaped lifting frame and an aramid fiber cloth, the outer arc surfaces of the arc-shaped lifting frame and the arc-shaped base frame are respectively placed on the inner surfaces of the upper and lower shield segments, a jack for lifting is arranged between the arc-shaped lifting frame and the arc-shaped base frame, and the outer arc surfaces of the arc-shaped base frame and / or the arc-shaped lifting frame are paved with an aramid fiber cloth;

[0009] The tunnel active external pressure control system comprises a drill bit and a drill rod with one end connected to the drill bit, a plurality of deformable bodies are distributed and fixed on the drill rod along the length direction, and the deformable body comprises an air bag equipped with an air injection system;

[0010] The tunnel active internal pressure control composite reinforcement system is arranged inside the tunnel, and the tunnel active external pressure control system is arranged on the side or / and below the tunnel;

[0011] The deformable body is fixed on the outside of the drill pipe by a metal sleeve, and the airbag is fixed to the metal sleeve at the edge with a clamp. The gas injection joint is connected through a pipeline and is responsible for injecting gas into the airbag. The externally connected pressure gauge measures the internal gas pressure in real time. Side foundation pit modules are set on both sides of the model test box structure. The side foundation pit modules include a simulation device of the ground-connected wall, and a 20mm thick PE board is used to simulate the ground-connected wall.

[0012] In the above model test device, the tunnel active external pressure control system is vertically arranged on the opposite sides of the outside of the tunnel deformation part, and the tunnel active external pressure control system is horizontally arranged below the outside of the tunnel deformation part.

[0013] In the above-mentioned model test device, the drill rod is a segmented structure, and two adjacent sections of the drill rod are threadedly connected to connect the segmented drill rods in series as a whole. A deformable body is fixed on each section of the drill rod, and a gas injection joint is led out from the airbag end of the deformable body. The gas injection joints between adjacent airbags are connected by connecting pipes to connect the airbags in series, and the airbag at the starting end is equipped with a gas injection system.

[0014] In the above model test device, a mounting sleeve is installed on the gas injection joint or the connecting pipe, and a bursting valve is installed on the mounting sleeve.

[0015] Furthermore, in order to facilitate the control of the pressure of active lifting and the regulation of the lifting range, a pressure gauge can be placed on the upper part of the jack to measure the change process of the lifting pressure and displacement;

[0016] Furthermore, the aramid fiber cloth can be used for the reinforcement of the tensile area of ​​the segment vault as well as the segment vault bottom;

[0017] Furthermore, in order to prevent the epoxy resin pasted on the aramid fiber cloth on the inner surface of the tunnel from accidentally pasting on the curved plate lifting frame, a layer of polytetrafluoroethylene plastic film is placed between the aramid fiber cloth and the curved plate lifting frame to play an isolating role;

[0018] Furthermore, the aramid fiber cloth is applied to the arc-shaped lifting frame and the arc-shaped bottom frame by a jack, so as to ensure that the aramid fiber cloth is more firmly attached during the local internal pressure lifting and simultaneous pasting;

[0019] Furthermore, in order to observe the soil pressure on the shield segment under the action of internal pressure lifting, several soil pressure boxes were placed around the segment to measure the confining pressure;

[0020] Furthermore, in order to facilitate the measurement of the displacement of the segment, a displacement meter is arranged inside the segment to measure the changes in the vertical and lateral convergence during the jacking process inside the segment, and at the same time, the active regulation of the segment by the airbag during the expansion process can be measured;

[0021] Furthermore, according to the displacement change of the pipe segment, multiple airbags can be arranged in series or in parallel to play a role of active compensation and regulation.

[0022] The present invention also provides a test method of an autonomous control model test device using shield tunnel deformation, comprising the following steps:

[0023] 1) Lay the soil layer in the model test box to the opening of the plexiglass, then put the assembled elliptical shield segments into the soil box, fill the soil layer with a height of 1 times the hole diameter, and tamp it;

[0024] 2) Place the tunnel active internal pressure control composite reinforcement system in the shield segment, and start the tunnel active internal pressure control composite reinforcement system to repair the elliptical deformation of the shield segment;

[0025] 3) Drill into the tunnel active external pressure control system in the horizontal direction below the outside of the tunnel, and inflate the airbag in the tunnel active external pressure control system, and lift the tunnel to a predetermined position through the tunnel active external pressure control system below. The elliptical tunnel will generally sink, and this step will lift the tunnel to its original position;

[0026] 4) Drill into the tunnel active external pressure control system vertically on opposite sides of the tunnel outside, and inflate the airbags in the tunnel active external pressure control system. After the shield segments are reset by the tunnel active external pressure control systems on both sides, the empty areas generated on both sides of the shield segments are filled.

[0027] In the above test methods, the specific use methods of the tunnel active internal pressure control composite reinforcement system and the tunnel active external pressure control system are as follows:

[0028] The arc-shaped bottom frame and the arc-shaped lifting frame are placed inside the shield lining, the outer arc surfaces of the arc-shaped lifting frame and the arc-shaped bottom frame are respectively placed on the inner surfaces of the upper and lower shield segments, a jack is vertically arranged between the arc-shaped lifting frame and the arc-shaped bottom frame, and an aramid fiber cloth adhered with epoxy resin is placed on the outer arc surface of the arc-shaped lifting frame and / or the arc-shaped bottom frame;

[0029] Start the jack to carry out the lifting work, and stick the aramid fiber cloth to the inner surface of the shield segment by means of the arc-shaped lifting frame and / or the arc-shaped bottom frame. At the same time, control the lifting force of the jack to restore the elliptical shield segment to a perfect circle or lift it to the designated position of the shield segment;

[0030] An active external pressure control system is drilled into the tunnel laterally below the outside of the tunnel. Specifically, the end of the drill rod is driven to drill into a designated position below the shield segment in the direction of the hole left in the ground-connected wall through the drill bit, so that the airbag reaches the predetermined position that needs to be actively lifted; the airbag is inflated to lift the sunken shield segment, and the lifting amount is actively controlled by controlling the inflation amount;

[0031] By the same method as above, the tunnel active external pressure control system 3 is vertically drilled on opposite sides of the tunnel exterior, and then the airbags on both sides are inflated. When the shield segments are reset, empty areas are generated on both sides of the exterior. The airbags on both sides squeeze the soil to fill the generated empty areas, thereby ensuring the stability of the external support environment during and after the tunnel repair process.

[0032] In the side foundation pit simulation module, multiple soil pressure boxes are set up step by step from top to bottom to measure the pressure changes of the soil.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The present invention adopts a method of actively regulating both inside and outside the pipe segment to ensure that the aramid fiber cloth and the repaired tunnel are firmly bonded under the condition of continuous stable pressure, and the fixing of the aramid fiber cloth and the tunnel repair are completed simultaneously. There is no need to repair the tunnel first and then paste the aramid fiber cloth, which saves manpower, material resources and time. It has the characteristics of adjustable pressure, stable pressure and guaranteed bonding, and has broad application prospects.

[0035] (2) The integrated design of the drilling rig and the airbag changes the traditional design of the airbag and drill rod. The front end of the drill rod is responsible for drilling, and an air inlet line is set on the bag sleeve to inflate the airbag, so that the goal of actively adjusting the displacement of the soil can be achieved in one drilling. This changes the original multi-step operation mode of drilling a hole first, removing the drill rod, and then placing the airbag.

[0036] (3) The present invention connects the airbag to the drill pipe body by means of a sleeve connection, and different airbag positions can be set or adjusted according to different geological conditions to achieve different control effects.

[0037] (4) The jack used in the present invention can adjust the height according to the requirements of the test lifting height. By adjusting the position of the jack, the jack applies a force to the vertical axis of the pipe segment to ensure uniform lifting.

[0038] (5) The present invention simulates the foundation pit on the side and, through the setting of the ground-connected wall, makes it possible for the drilling rig to drill through the hole in the ground-connected wall, thus changing the method of long-distance drilling from the ground, shortening the construction distance and making the positioning more accurate.

[0039] (6) The arch bottom of the pipe segment of the present invention can also be reinforced with aramid fiber cloth, and the effect of synchronous repair and reinforcement of the pipe segment arch top and arch bottom can be achieved.

[0040] (7) The model test box in the present invention is easy to assemble and disassemble, and can be modified according to the specific requirements of the test. It is multifunctional and suitable for research under different geological conditions, and then various geotechnical tests related to shield tunnel repair and reinforcement, cave filling, bag grouting, etc. under different working conditions can be carried out. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0042] Figure 1 It is a front view of the model test device for shield tunnel lining in Example 1 of the present invention;

[0043] Figure 2 is a three-dimensional schematic diagram of the structure of the model test box in Example 1 of the present invention;

[0044] Figure 3 It is a schematic diagram of the active control system for shield tunnel lining in Example 1 of the present invention;

[0045] Figure 4 Schematic diagram of the active internal pressure control device for a shield tunnel in Example 1 of the present invention;

[0046] Figure 5 is a schematic diagram of the tunnel active external pressure control system in Example 1 of the present invention;

[0047] Figure 6 Detailed schematic diagram of the tunnel active external pressure regulating airbag in Example 1 of the present invention;

[0048] Figure 7 It is a schematic diagram of the side foundation pit module of the shield tunnel in Example 1 of the present invention;

[0049] Figure 8 is a schematic diagram of the change of the stratum morphology in Example 1 of the present invention;

[0050] Fig. 9 It is a schematic diagram of embodiment 3 of the present invention.

[0051] In the figure: 1—model test box structure; 2—tunnel active internal pressure control composite reinforcement system; 3—tunnel active external pressure control system; 4—lateral foundation pit module; 11—middle column; 12—corner column; 13—side channel steel; 14—transverse channel steel; 15—plexiglass panel; 20—pressure gauge; 21—shield segment (shield tunnel lining); 22—aramid fiber cloth; 23—arc-shaped lifting frame; 24—jack; 25—limiting fixed seat; 26—arc-shaped base frame; 27—epoxy resin; 28—arc-shaped lifting frame arc plate; 29—rib plate; 30—deformed body; 31—drill bit; 32—connection Drill rod; 33—air bag; 34—connecting pipe; 35—pressure gauge; 36—gas injection joint; 37—clamp; 38—burst valve; 39—installation sleeve; 41—foundation pit; 42—ground-connected wall; 43—circular hole; 61—karst cave; 71—surface stratigraphic line before internal pressure lifting; 72—surface stratigraphic line after internal pressure lifting; 73—tunnel before internal pressure lifting; 74—tunnel after internal pressure lifting; 75—tunnel vault stratigraphic line before internal pressure lifting; 76—tunnel vault stratigraphic line after internal pressure lifting; 77—tunnel arch bottom stratigraphic line before internal pressure lifting; 78—tunnel arch bottom stratigraphic line after internal pressure lifting; 79—earth pressure box. DETAILED DESCRIPTION

[0052] Example 1

[0053] like Figure 1As shown, a model test device for autonomous control of a shield tunnel includes a model test box structure 1, a tunnel active internal pressure control composite reinforcement system 2, a tunnel active external pressure control system 3, a side foundation pit module 4 and other components.

[0054] like Figure 2 The model test box structure 1 shown is surrounded by a fully transparent organic glass panel 15 to form a rectangular parallelepiped structure, and circular holes matching the shield segments 21 are opened on the front and rear panels; the outer periphery is made of overlapping steel frames, the middle columns 11 and the corner columns 12 are arranged vertically, the channel steels 14 are arranged horizontally, and the side channel steels 13 are arranged horizontally. The channel steels are connected by high-strength bolts, which makes it easy to adjust the size of the model test box according to test needs.

[0055] like Figure 3 As shown, in the shield tunnel lining active control module 2, there is an elliptical shield segment 21 in the stratum, and the shield segment can be restored to a standard circular tunnel by using an arc-shaped jacking frame 23 and an arc-shaped bottom frame 26 under the jacking action of a jack 24. As shown in the figure, the arc-shaped jacking frame 23 and the arc-shaped bottom frame 26 are fixedly connected at the top and bottom respectively by connecting high-strength bolts to prevent the arc-shaped jacking frame 23 from becoming unstable.

[0056] like Figure 4 As shown, the outer surface of the aramid fiber cloth 22 is coated with epoxy resin glue 27 for tunnel reinforcement, and is flattened and placed on the outer surface of the arc plate 28 of the arc jacking frame. In order to prevent the epoxy resin pasted on the aramid fiber cloth 22 on the inner surface of the tunnel from accidentally pasting on the arc plate jacking frame 23, a layer of polytetrafluoroethylene plastic film is placed between the aramid fiber cloth and the arc plate jacking frame to play an isolating role. During the jacking process of the jack 24, the force is transmitted to the inner surface of the fiber cloth and the pipe segment through the rib plate 29, ensuring that the aramid fiber cloth 22 is pasted synchronously under local internal pressure, so that the pasting and pasting are more firm. It is different from the traditional method of jacking first and then pasting, and solves the problem of how to effectively improve the pasting effect of the fiber cloth. As a flexible reinforcement material, the aramid fiber cloth 22 has extremely high tensile strength. It is used to reinforce the tensile area of ​​concrete, which is easy to construct and has a fast reinforcement speed, and can improve the strength of the shield pipe segment.

[0057] like Figure 5 and Figure 6The figure shows a schematic diagram of a tunnel active external pressure control system 3. In this embodiment, the tunnel active external pressure control system 3 is arranged in 1D below the tunnel. The tunnel active external pressure control system 3 includes a drill bit 31 and a drill rod 32 with one end connected to the drill bit 31. A plurality of deformable bodies 30 are fixedly arranged along the length direction of the drill rod 32. The deformable body 30 includes an air bag 33 equipped with an air injection system. The rear end of the drill rod 34 is matched with a power source. The drill bit 31 drills in the soil layer under the action of power. The deformable body 30 is fixed on the outside of the drill rod 34 by a metal sleeve. The air bag 33 is fixed to the metal sleeve at the edge by a clamp 37. The gas injection joint 36 is connected by a pipeline and is responsible for injecting gas into the air bag 33. The externally connected pressure gauge measures the internal gas pressure in real time. The drill rod 32 selects a segmented structure. Two adjacent sections of the drill rod 32 are threadedly connected to connect the segmented drill rod 32 in series as a whole. A deformable body 30 is fixed on each section of the drill rod 32. A gas injection joint 36 is led out from the end of the airbag 33, and the gas injection joints 36 between adjacent airbags 33 are connected by connecting pipes 34 to connect the airbags 33 in series. The airbag 33 at the starting end is equipped with a gas injection system. A mounting sleeve 39 is installed on the gas injection joint 36 or the connecting pipe 34. The mounting sleeve 39 can be selectively welded on the deformable body 30. A bursting valve 38 is installed in the middle position of the mounting sleeve 39. The bursting pressure of the bursting valve 38 is related to the pressure of the airbag 33. The bursting valve 38 can only burst when the airbag 33 is completely filled with gas to achieve the goal of controlling the displacement of the soil body. The higher the pressure, the better, but it cannot be greater than the pressure at which the airbag 33 is burst. The function of the bursting valve 38 is that the bursting valve 38 opens after the previous airbag 33 is filled and reaches the set pressure, and the gas is sent to the next airbag 33 through the connecting pipe 34 to inflate the next airbag 33. By analogy, the series-connected airbags 33 are inflated to make the deformable bodies 30 expand one by one and squeeze the surrounding soil.

[0058] like Figure 7 As shown, the side foundation pit simulation module 4 is arranged on the inner side of the outer frame and on the side of the shield segment 21. The side foundation pit simulation module 4 divides the soil into two parts through the ground connection wall 42, the left side is the test main part, and the right side is the foundation pit 41 part. A groove 43 (opening) is opened in the lower part of the ground connection wall 42 to facilitate the operation of the tunnel active external pressure control system 3. The ground connection wall 42 is inserted into the organic glass panel 15 through a slot for fixing. The ground connection wall 42 is a 20mm thick PE sheet. Three isolation supports 44 are set on the side of the foundation pit to ensure the safety of the foundation pit support.

[0059] like Figure 8As shown, the present invention is mainly aimed at the schematic diagram of the stratum morphology changes caused by the new method of active repair and reinforcement management of the elliptical tunnel. The stratum line 71 before local internal pressure lifting is "V"-shaped, and the surface line 72 after partial internal pressure lifting deformation is almost horizontal. The tunnel 73 constructed by the shield segment 21 is elliptical before loading, and becomes a circular tunnel 74 after partial internal pressure lifting deformation. The original soil layer 75 in the upper part of the tunnel is transformed into the deformed soil layer 76. Similarly, under the action of the tunnel active external pressure control system 3, the soil layer at the bottom of the tunnel is changed from the original soil layer 77 to the subsequent soil layer 78. A plurality of soil pressure boxes 79 are provided to facilitate understanding of the pressure changes of the soil after the active control method is adopted.

[0060] The test method using the above-mentioned shield tunnel deformation self-regulating model test device comprises the following steps:

[0061] 1) Lay the soil layer in the model test box 1 to the position of the organic glass opening, then put the assembled elliptical shield segment 21 into the soil box, fill it with soil layer of 1 times the hole diameter, and tamp it;

[0062] 2) placing the tunnel active internal pressure control composite reinforcement system 2 in the shield segment 21, and starting the tunnel active internal pressure control composite reinforcement system 2 to repair the elliptical deformation of the shield segment 21;

[0063] 3) Drill into the tunnel active external pressure control system 3 laterally below the outside of the tunnel, and inflate the airbag 33 in the tunnel active external pressure control system 3, so that the tunnel is lifted to a predetermined position through the tunnel active external pressure control system 3 below. The elliptical tunnel generally sinks, and this step lifts the tunnel to its original position;

[0064] Specifically, the arc-shaped bottom frame 26 and the arc-shaped lifting frame 23 are placed inside the shield lining, the outer arc surfaces of the arc-shaped lifting frame 23 and the arc-shaped bottom frame 26 are respectively placed on the inner surfaces of the upper and lower shield segments 21, the jack 24 is vertically placed between the arc-shaped lifting frame 23 and the arc-shaped bottom frame 26, and the aramid fiber cloth 22 with epoxy resin 27 is placed on the outer arc surface of the arc-shaped lifting frame 23 and / or the arc-shaped bottom frame 26;

[0065] The jack 24 is started to perform the lifting work, and the aramid fiber cloth 22 is adhered to the inner surface of the shield segment 21 by means of the arc-shaped lifting frame 23 and / or the arc-shaped bottom frame 26. At the same time, the lifting force of the jack 24 is controlled to restore the elliptical shield segment 21 to a perfect circle or lift it to a designated position of the shield segment 21;

[0066] The active external pressure control system 3 of the tunnel is drilled in the horizontal direction below the outside of the tunnel, specifically: the end of the drill rod 32 is driven to drill into the designated position below the shield segment 21 in the horizontal direction from the hole left in the ground connection wall 42 through the drill bit 31, so that the airbag 33 reaches the predetermined position that needs to be actively lifted; the airbag 33 is inflated to lift the sunken shield segment 21, and the lifting amount is actively controlled by controlling the inflation amount;

[0067] In the side foundation pit simulation module, multiple soil pressure boxes 79 are arranged step by step from top to bottom to measure the pressure change of the soil.

[0068] Example 2

[0069] The difference between this embodiment and embodiment 1 is that the tunnel active external pressure control system 3 of this embodiment also adopts the vertical drilling method to control the soil displacement, so as to achieve the effect of filling the soil voids on both sides of the shield segment 21. Based on this idea, the shield segment 21 can be elliptical in any direction, and this method can be used to control the filling and compaction of local soil voids. In this embodiment, the tunnel active external pressure control system 3 is drilled vertically on both sides of the tunnel, and the soil on both sides of the shield segment 21 is squeezed by inflating the airbag, so that the voids on both sides of the shield segment 21 are filled and compacted during the process of restoring the round shape.

[0070] Example 3

[0071] like Fig. 9 As shown, the difference between this embodiment and embodiment 1 is that the tunnel active external pressure control system 3 of this embodiment also adopts the vertical drilling method to control the soil displacement, so as to achieve the overall displacement effect of actively controlling the shield segment 21. Based on this idea, the shield segment 21 can be locally actively controlled in any orientation when it undergoes elliptical change. In this embodiment, the tunnel active external pressure control system 3 is drilled vertically on the right side of the tunnel diagram, and the shield segment 21 is squeezed by inflating the airbag to move the shield segment 21 to the left, or the soil on the right side of the shield segment 21 is squeezed to fill and compact the empty area on the right side of the shield segment 21.

[0072] It should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting the intention that the claimed invention requires more features than those expressly recited in each claim. Rather, as reflected in the claims, inventive aspects lie in less than all of the features of the previously disclosed embodiments. Therefore, the claims that follow the detailed description are hereby expressly incorporated into the detailed description, with each claim itself serving as a separate embodiment of the present invention.

Claims

1. A shield tunnel deformation self-regulating model test device, comprising a model test box structure (1), wherein the model test box structure (1) is an outer frame mainly formed by lap-jointing channel steel (13) and corner columns (12), and the interior is surrounded by organic glass panels to form a rectangular parallelepiped structure; the characteristics are: It also includes a tunnel active internal pressure control composite reinforcement system (2) and a tunnel active external pressure control system (3); The tunnel active internal pressure control composite reinforcement system (2) comprises an arc-shaped base frame (26), a jack (24), an arc-shaped lifting frame (23) and an aramid fiber cloth (22); the outer arc surfaces of the arc-shaped lifting frame (23) and the arc-shaped base frame (26) are respectively placed on the inner surfaces of the shield segments (21) on the upper and lower sides; a jack (24) for lifting is arranged between the arc-shaped lifting frame (23) and the arc-shaped base frame (26); and the outer arc surfaces of the arc-shaped base frame (26) and / or the arc-shaped lifting frame (23) are paved with an aramid fiber cloth (22); The tunnel active external pressure control system (3) comprises a drill bit (31) and a drill rod (32) with one end connected to the drill bit (31), a plurality of deformable bodies (30) are distributed and fixed on the drill rod (32) along the length direction, and the deformable body (30) comprises an air bag (33) equipped with an air injection system; The tunnel active internal pressure control composite reinforcement system (2) is arranged inside the tunnel, and the tunnel active external pressure control system (3) is arranged on the side or / and below the tunnel.

2. The shield tunnel deformation self-regulating model test device according to claim 1, characterized in that: The tunnel active external pressure control system (3) is respectively arranged vertically on two opposite sides of the outside of the tunnel deformation part, and the tunnel active external pressure control system (3) is arranged horizontally below the outside of the tunnel deformation part.

3. The shield tunnel deformation self-regulating model test device according to claim 1, characterized in that: The drill rod (32) is a segmented structure. Two adjacent segments of the drill rod (32) are threadedly connected to connect the segmented drill rods (32) in series as a whole. A deformable body (30) is fixed on each segment of the drill rod (32). A gas injection joint (36) is led out from the end of the airbag (33) of the deformable body (30). The gas injection joints (36) between adjacent airbags (33) are connected through a connecting pipe (34) to connect the airbags (33) in series. The airbag (33) at the starting end is equipped with a gas injection system.

4. The self-regulating model test device for shield tunnel deformation according to claim 3 is characterized by: The gas injection joint (36) or the connecting pipe (34) is provided with a mounting sleeve (39), and a bursting valve (38) is provided on the mounting sleeve (39).

5. The shield tunnel deformation self-regulating model test device according to claim 1, characterized in that: A plurality of earth pressure boxes (79) are placed around the pipe segments in the model test box structure (1) to measure the tunnel confining pressure.

6. The shield tunnel deformation self-regulating model test device according to claim 1, characterized in that: The lower surface of the arc-shaped lifting frame (23) and the upper surface of the arc-shaped base frame (26) are both lifting planes, and the jack (24) is located between the two lifting planes. Two jacks (24) of the same type are distributed and arranged between the two lifting planes, and their acting force is to lift synchronously to prevent the arc-shaped lifting frame (23) from tipping over.

7. The shield tunnel deformation self-regulating model test device according to claim 1, characterized in that: A jack limit fixing seat (25) is provided at the upper end of the arc-shaped base frame (26), and the base of the jack (24) is placed on the jack limit fixing seat (25); a pressure gauge (20) is additionally provided on the upper part of the jack (24).

8. The shield tunnel deformation self-regulating model test device according to claim 1, characterized in that: A layer of polytetrafluoroethylene plastic film is placed between the aramid fiber cloth (22) and the arc-shaped plate lifting frame (23).

9. A test method using an autonomous control model test device for shield tunnel deformation, characterized in that: The following steps are involved: 1) Lay a soil layer in the model test box (1) to the position of the organic glass opening, then put the assembled shield segment (21) that has been elliptical into the soil box, fill it with a soil layer of 1 times the hole diameter, and tamp it; 2) placing the tunnel active internal pressure control composite reinforcement system (2) in the shield segment (21), and starting the tunnel active internal pressure control composite reinforcement system (2) to repair the elliptical deformation of the shield segment (21); 3) drilling into the tunnel active external pressure control system (3) in the horizontal direction below the outside of the tunnel, and inflating the airbag (33) in the tunnel active external pressure control system (3), so as to lift the tunnel to a predetermined position through the tunnel active external pressure control system (3) below; 4) Drilling into the tunnel active external pressure control system (3) vertically on opposite sides of the tunnel exterior, and inflating the airbag (33) in the tunnel active external pressure control system (3), after the shield segment (21) is reset by the tunnel active external pressure control systems (3) on both sides, the empty areas generated outside the shield segment (21) on both sides are filled.

10. The test method according to claim 9, characterized in that: The specific use methods of the tunnel active internal pressure control composite reinforcement system (2) and the tunnel active external pressure control system (3) are as follows: The arc-shaped bottom frame (26) and the arc-shaped lifting frame (23) are placed inside the shield lining, the outer arc surfaces of the arc-shaped lifting frame (23) and the arc-shaped bottom frame (26) are respectively placed on the inner surfaces of the shield segments (21) on the upper and lower sides, a jack (24) is vertically arranged between the arc-shaped lifting frame (23) and the arc-shaped bottom frame (26), and an aramid fiber cloth (22) adhered with epoxy resin (27) is placed on the outer arc surfaces of the arc-shaped lifting frame (23) and / or the arc-shaped bottom frame (26); The jack (24) is started to perform lifting work, and the aramid fiber cloth (22) is adhered to the inner surface of the shield segment (21) by means of the arc-shaped lifting frame (23) and / or the arc-shaped bottom frame (26). At the same time, the lifting force of the jack (24) is controlled so that the elliptical shield segment (21) is restored to a perfect circle or lifted to a designated position of the shield segment (21); An active external pressure control system (3) is drilled into the tunnel in the horizontal direction below the outside of the tunnel, specifically: the end of the drill rod (32) is driven to drill into a designated position below the shield segment (21) in the horizontal direction from the hole left in the ground-connected wall (42) through the drill bit (31), so that the air bag (33) reaches a predetermined position that needs to be actively lifted; the air bag (33) is inflated so that the subsided shield segment (21) is lifted, and the lifting amount is actively controlled by controlling the inflation amount; By the same method as above, the tunnel active external pressure control system (3) is vertically drilled into opposite sides of the tunnel exterior, and then the air bags (33) on both sides are inflated. When the shield segment (21) is reset, empty areas are generated on both sides of the exterior. At the same time, the air bags (33) on both sides squeeze the soil to fill the generated empty areas, thereby ensuring the stability of the external support environment during and after the tunnel repair process. In the side foundation pit simulation module, a plurality of soil pressure boxes (79) are arranged step by step from top to bottom to measure the pressure change of the soil body.

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