Coupling loading test device for simulating thrust force of shield segment and brush pressure of shield tail

Abstract

The application provides a coupling loading test device for simulating the thrust force of a shield segment and the brush pressure of a shield tail, comprising: a fixing device for limiting the displacement of a segment test piece, a counterforce device for providing a counterforce for loading, a horizontal loading device for simulating the thrust force of a shield machine, a vertical loading device for simulating the brush pressure of a shield tail, and a testing device for detecting the strain distribution of the segment test piece; the segment test piece is installed on the fixing device, one side of the segment test piece is in contact with a horizontal limiting block, the other side is in abutment with the horizontal loading device, the outer side of the segment test piece is in abutment with the vertical loading device, and the horizontal and vertical loading devices perform coupling loading on the segment test piece under the balance of the counterforce device. The device is used for simulating the combined action of the thrust force of a shield segment and the brush pressure of a shield tail in the process of shield propulsion, and is used for studying the stress condition, deformation characteristics and failure mode of the shield segment under the load.

Description

Technical Field

[0001] This invention relates to a coupled loading test device for simulating the thrust of tunnel segments and the pressure of the tail brush. Background Technology

[0002] The so-called shield tunnel segment is the main assembly component in shield tunneling. It is the innermost barrier of the tunnel, which bears the responsibility of resisting soil pressure, groundwater pressure and some special loads. It is the permanent lining structure of shield tunnel.

[0003] The tail brush, also known as the tail sealing brush, is an important component of tunnel boring machines (TBMs). It prevents soil, sand, groundwater, injected grout, and mud from the excavation face from flowing into the TBM through the tail gap. While the tail brush itself has a certain degree of elasticity, its stiffness increases and its elasticity decreases over time. When the TBM performs attitude corrections, the tail brush may compress the tunnel lining segments, causing excessive localized stress and potentially leading to cracking or even damage to the segments.

[0004] Therefore, a coupled loading test device and method for simulating the thrust of shield tunnel segments and the pressure of the tail brush is needed to simulate the combined effect of thrust and tail brush pressure on shield tunnel segments during shield tunneling, and to study the stress, deformation characteristics and failure modes of shield tunnel segments under this load. Summary of the Invention

[0005] The main technical problem to be solved by this invention is to provide a coupled loading test device for simulating the jacking force and tail brush pressure of shield tunnel segments, so as to simulate the combined action of jacking force and tail brush pressure on shield tunnel segments during shield tunneling, and to study the stress, deformation characteristics and failure mode of shield tunnel segments under this load.

[0006] To solve the above-mentioned technical problems, the present invention provides a coupled loading test device for simulating the jacking force of shield tunnel segments and the tail brush pressure, comprising: a fixing device for limiting the displacement of the segment specimen, a reaction force device for providing a reaction force for loading, a horizontal loading device for simulating the jacking force of the shield machine, a vertical loading device for simulating the tail brush pressure, and a test device for detecting the strain distribution of the segment specimen.

[0007] The segment specimen is installed on the fixing device. One side of the segment specimen is in contact with the horizontal limiting block, the other side of the segment specimen is in contact with the horizontal loading device, and the outer side of the segment specimen is in contact with the vertical loading device. The horizontal and vertical loading devices are coupled to load the segment specimen under the balance of the reaction device.

[0008] In a preferred embodiment: the fixing device includes a rotating baffle, a base, tie bolts, and a horizontal limiting block;

[0009] The rotating baffle is rotatably connected to the base to form a rotating support; the tie bolt passes through the two symmetrically distributed rotating supports to limit the relative horizontal displacement of the two rotating supports; the horizontal limiting block is fixed to the reaction device by bolts.

[0010] In a preferred embodiment: the reaction device includes a reaction frame, a horizontal loading reaction beam, and a vertical loading reaction beam;

[0011] The reaction frame includes a crossbeam and a column, with the two reaction frames placed in parallel; the horizontal loading reaction beam is fixed to one side column of the two reaction frames by bolts; the vertical loading reaction beam is fixed to the crossbeam of the two reaction frames by bolts.

[0012] In a preferred embodiment: the horizontal loading device includes a horizontal jack and a pressure sensor;

[0013] One end of the horizontal jack is fixed to the horizontal loading reaction beam, and the other end is connected to a pressure sensor. The other end of the pressure sensor abuts against the annular surface of the segment specimen.

[0014] In a preferred embodiment: the vertical loading device includes a vertical jack, a pressure sensor, and a load distribution beam;

[0015] The load distribution beam is placed on the tunnel segment specimen. The load distribution beam is customized according to the size of the test tunnel segment to ensure that the load distribution beam fits the tunnel segment specimen so that the load is evenly distributed. One end of the vertical jack is fixed to the vertical loading reaction beam, and the other end is connected to the pressure sensor. The other end of the pressure sensor abuts against the load distribution beam.

[0016] In a preferred embodiment: the testing apparatus includes strain gauges, strain rosettes, and a crack tester;

[0017] The strain gauges are arranged at intervals and adhered to the surface of the tube segment specimen; the strain rosettes are adhered to the annular surface of the tube segment specimen that abuts against the horizontal loading device and the inner surface of the tube segment specimen, and are used to measure the principal strain distribution in the weak parts of the tube segment specimen; the crack tester is used to measure the cracks that appear in the tube segment specimen during loading.

[0018] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0019] 1. The test device is simple and easy to operate. The tunnel segment specimen is fixed by a fixing device, and the combined action of the jacking force and the tail brush pressure on the shield tunnel segment is simulated by horizontal and vertical loading devices. The surface strain of the tunnel segment specimen is measured by strain gauges, and the principal strain of the weak part of the tunnel segment specimen is measured by strain rosettes. By comparing the cracks that appear during the loading process, the stress condition, deformation characteristics and failure mode of the shield tunnel segment can be clarified.

[0020] 2. The two symmetrically distributed bases in the fixing device can be adjusted according to the size of the segment specimen, and are applicable to segment specimens of any size.

[0021] 3. The horizontal and vertical loading devices can be connected to different positions of the horizontal and vertical loading reaction beams as needed to accommodate loading of segment specimens of different sizes.

[0022] 4. The load distribution beam is customized according to the size of the segment specimen, and a horizontal platform is added at each of its four division points to ensure that the load is transferred vertically and evenly downward. Attached Figure Description

[0023] Figure 1 A front view of a preferred embodiment of a test apparatus for simulating the coupled loading of shield tunnel segment thrust and tail brush pressure is shown.

[0024] Figure 2 A side view of a preferred embodiment of a coupled loading test apparatus for simulating the thrust of a tunnel segment and the pressure of the tail brush is shown.

[0025] Figure 3 A schematic diagram of the inner side surface of a segment according to a preferred embodiment is shown;

[0026] Figure 4 A schematic diagram of the annular surface of a segment specimen in a preferred embodiment abutting against a horizontal loading device is shown.

[0027] In the diagram: Fixing device—1; Reaction device—2; Horizontal loading device—3; Vertical loading device—4; Rotating baffle—11; Base—12; Tie bolt—13; Horizontal limit block—14; Reaction frame—21; Horizontal loading reaction beam—22; Vertical loading reaction beam—23; Horizontal jack—31; Pressure sensor—32, 42; Vertical jack—41; Load distribution beam—43; Strain gauge—51; Strain rosette—52. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed", "equipped", "sleeved / connected", "connected", etc., should be interpreted broadly. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0031] refer to Figures 1-4 This embodiment provides a coupled loading test device for simulating the thrust of a tunnel segment and the pressure of the tail brush, including: a fixing device 1 for limiting the displacement of the segment specimen, a reaction device 2 for providing a reaction force for loading, a horizontal loading device 3 for simulating the thrust of the tunnel machine, a vertical loading device 4 for simulating the pressure of the tail brush, and a test device for detecting the strain distribution of the segment specimen.

[0032] The segment specimen is installed on the fixing device 1. One side of the segment specimen is in contact with the horizontal limiting block, and the other side of the segment specimen is in contact with the horizontal loading device 3. The outer side of the segment specimen is in contact with the vertical loading device 4. The horizontal and vertical loading devices 4 perform coupled loading on the segment specimen under the balance of the reaction device 2.

[0033] The fixing device 1 includes a rotating baffle 11, a base 12, a tie bolt 13, and a horizontal limiting block 14; the rotating baffle 11 is rotatably connected to the base 12 to form a rotating support; the tie bolt 13 passes through the two symmetrically distributed rotating supports to limit the relative horizontal displacement of the two rotating supports; the horizontal limiting block 14 is fixedly connected to the reaction device 2 by bolts.

[0034] The reaction device 2 includes a reaction frame 21, a horizontal loading reaction beam 22, and a vertical loading reaction beam 23; the reaction frame 21 includes a crossbeam and a column, and the two reaction frames 21 are placed in parallel; the horizontal loading reaction beam 22 is fixedly connected to one side column of the two reaction frames 21 by bolts; the vertical loading reaction beam 23 is fixedly connected to the crossbeam of the two reaction frames 21 by bolts.

[0035] The horizontal loading device 3 includes a horizontal jack 31 and a pressure sensor 32; one end of the horizontal jack 31 is fixedly connected to the horizontal loading reaction beam 22, and the other end is connected to the pressure sensor 32, and the other end of the pressure sensor 32 abuts against the annular surface of the segment specimen.

[0036] The vertical loading device 4 includes a vertical jack 41, a pressure sensor 42, and a load distribution beam 43. The load distribution beam 43 is placed on the tunnel segment specimen and is customized according to the size of the test tunnel segment to ensure that the load distribution beam 43 fits snugly with the tunnel segment specimen so that the load is evenly distributed. One end of the vertical jack 41 is fixedly connected to the vertical loading reaction beam 23, and the other end is connected to the pressure sensor 42. The other end of the pressure sensor 42 abuts against the load distribution beam 43.

[0037] The testing device includes strain gauges 51, strain rosettes 52, and a crack tester; the strain gauges 51 are arranged at intervals and are attached to the surface of the segment specimen; the strain rosettes 52 are attached to the annular surface of the segment specimen that abuts against the horizontal loading device 3 and the inner surface of the segment specimen, and are used to measure the principal strain distribution in the weak parts of the segment specimen; the crack tester is used to measure the cracks that appear in the segment specimen during loading.

[0038] During the test, the segment specimen is first placed horizontally, the segment specimen is installed on the fixing device 1, and one side of the segment specimen is pressed against the horizontal limiting block 14. Then the tie bolts passing through the two bases 12 are locked to ensure that the segment specimen does not cause support displacement during the loading process.

[0039] Next, the load distribution beam 43 in the vertical loading device 4 is installed on the outer surface of the segment specimen. The vertical jack 41 is fixed to the vertical loading reaction beam 23, so that the vertical jack 41 and the load distribution beam 43 are aligned to ensure that the load is transmitted vertically and evenly downward. The pressure sensor 42 is connected to the vertical jack 41, and the vertical jack 41 is adjusted so that the pressure sensor 42 presses against the load distribution beam 43.

[0040] Next, the horizontal jack is fixed to the horizontal loading reaction beam 22, the pressure sensor 32 is connected to the horizontal jack, and the horizontal jack is adjusted so that the pressure sensor 32 presses against one side of the tube segment specimen.

[0041] Then, the horizontal jacks were adjusted to apply a horizontal load to the segment specimen to simulate the thrust of the tunnel boring machine and maintain it at a certain pressure. Then, the vertical jacks 41 were adjusted to apply a vertical load to the segment specimen step by step to simulate the tail brush pressure until failure, thereby obtaining the relationship between the strain distribution of the segment specimen and the tail brush pressure. Finally, by observing whether cracks appeared at each loading level, the relationship between crack appearance and principal strain was studied.

[0042] The above description is merely a preferred embodiment of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention by those skilled in the art within the scope of the technology disclosed in the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. A coupled loading test device for simulating the jacking force of tunnel segments and the pressure of the shield tail brush, characterized in that... include: Fixing device for limiting the displacement of tunnel segment specimens, reaction force device for providing reaction force for loading, horizontal loading device for simulating the thrust of a tunnel boring machine, vertical loading device for simulating the tail brush pressure of the shield, and testing device for detecting the strain distribution of tunnel segment specimens. The segment specimen is mounted on a fixing device. One side of the segment specimen's annular surface contacts the horizontal limiting block, and the other side of the annular surface abuts against the horizontal loading device. The outer side of the segment specimen abuts against the vertical loading device. The horizontal and vertical loading devices perform coupled loading on the segment specimen under the balance of the reaction force device. The fixing device includes a rotating baffle, a base, tie bolts, and a horizontal limiting block. The rotating baffle is rotatably connected to the base to form a rotating support; the tie bolt passes through the two symmetrically distributed rotating supports, limiting the relative horizontal displacement of the two rotating supports; the horizontal limiting block is fixed to the reaction device by bolts; the reaction device includes a reaction frame, a horizontal loading reaction beam and a vertical loading reaction beam; The reaction frame includes a crossbeam and a column, with the two reaction frames placed in parallel; the horizontal loading reaction beam is fixed to one side column of the two reaction frames by bolts; the vertical loading reaction beam is fixed to the crossbeam of the two reaction frames by bolts; the horizontal loading device includes a horizontal jack and a first pressure sensor. One end of the horizontal jack is fixed to the horizontal loading reaction beam, and the other end is connected to one end of the first pressure sensor. The other end of the first pressure sensor abuts against the annular surface of the segment specimen. The vertical loading device includes a vertical jack, a second pressure sensor, and a load distribution beam. The load distribution beam is placed on the tunnel segment specimen. The load distribution beam is customized according to the size of the test tunnel segment to ensure that the load distribution beam fits the tunnel segment specimen so that the load is evenly distributed. One end of the vertical jack is fixed to the vertical loading reaction beam, and the other end is connected to one end of the second pressure sensor. The other end of the second pressure sensor abuts against the load distribution beam. The testing device includes strain gauges, strain rosettes, and crack testers. The strain gauges are arranged at intervals and adhered to the surface of the tube segment specimen; the strain rosettes are adhered to the annular surface of the tube segment specimen that abuts against the horizontal loading device and the inner surface of the tube segment specimen, and are used to measure the principal strain distribution in the weak parts of the tube segment specimen; the crack tester is used to measure the cracks that appear in the tube segment specimen during loading. During the test, the segment specimen is first placed horizontally, the segment specimen is installed on the fixing device, and one side of the segment specimen is pressed against the horizontal limiting block. Then the tie bolts that pass through the two bases are locked. Next, the load distribution beam in the vertical loading device is installed on the outer side of the segment specimen. The vertical jack is fixed to the vertical loading reaction beam so that the vertical jack is aligned with the load distribution beam. The second pressure sensor is connected to the vertical jack. The vertical jack is adjusted so that the pressure sensor presses against the load distribution beam. Next, the horizontal jack is fixed to the horizontal loading reaction beam, the first pressure sensor is connected to the horizontal jack, and the horizontal jack is adjusted so that the pressure sensor presses against one side of the annular surface of the tube segment specimen. Then, the horizontal jacks were adjusted to apply a horizontal load to the segment specimen to simulate the top thrust of the tunnel boring machine. The vertical jacks were then adjusted to apply a vertical load to the segment specimen step by step to simulate the tail brush pressure until failure, thereby obtaining the relationship between the strain distribution of the segment specimen and the tail brush pressure. Finally, by observing whether cracks appear at each loading level, the relationship between crack occurrence and principal strain was studied.

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