A measuring device and construction method for the compression amount of a yielding support buffer layer in a tunnel

Abstract

The present application discloses a measuring device and construction method for the compression amount of a tunnel yielding support buffer layer, which is used to measure the compression deformation amount of the buffer layer located between the primary support and the secondary lining. The device includes a measuring body and a double-layer protection component. The measuring body has a first end and a second end. The double-layer protection component is sleeved outside the measuring body and includes an inner protection sleeve and an outer protection sleeve nested with each other. One end of the inner protection sleeve is fixedly connected to the first fixing member, and the other end passes through the buffer layer and extends into the outer protection sleeve. One end of the outer protection sleeve is fixedly arranged on the wall surface of the buffer layer facing the secondary lining, and the other end extends towards the secondary lining and protrudes, and is fixedly connected to the second end of the measuring body through a second fixing member. The present application realizes the measurement and monitoring of the compression deformation amount of the tunnel buffer layer, and provides a basis for the evaluation index and dynamic design of the buffer layer support effect.

Description

Technical Field

[0001] This application relates to the technical field of tunnel surrounding rock monitoring, and particularly to a device and construction method for measuring the compression amount of a yielding support buffer layer in a tunnel. Background Technique

[0002] Under complex geological and high in-situ stress conditions, the soft surrounding rock has a large deformation and a long duration. The strong rigid support system has poor deformation ability, resulting in serious damage and intrusion of the primary support during the construction period of soft rock underground engineering, and frequent cracking, spalling, and floor heave diseases of the lining structure during the operation period. The buffer layer support absorbs excessive deformation energy of the surrounding rock by arranging buffer materials or buffer structures with high compression amount and constant resistance mechanical properties between the support structure layers. Especially in the working condition of formation bias pressure, it plays a good role in adjusting the uniformity inside the lining structure and has received more and more attention.

[0003] However, as a relatively new technical means and a concealed structure, after the buffer layer is applied to a real tunnel, its compression deformation amount, as an important evaluation index for the buffer layer support effect and the basis for dynamic design, has always lacked relevant monitoring and measuring devices and suitable measuring methods. The compression deformation measurement of the buffer layer support is affected by on-site construction, especially the casting of the secondary lining, and it is difficult to construct and observe. Currently, more estimations of the buffer layer compression amount are based on experience and numerical simulation results, lacking the verification of actual monitoring data. Summary of the Invention

[0004] In order to solve the above problems, the embodiments of this application provide a device and construction method for measuring the compression amount of a yielding support buffer layer in a tunnel. The technical solution is as follows:

[0005] In the first aspect of this application, a device for measuring the compression amount of a yielding support buffer layer in a tunnel is provided, which is used to measure the compression deformation amount of the buffer layer located between the primary support and the secondary lining. It includes a measuring body and a double-layer protection component. The measuring body has a first end and a second end. The first end is fixedly arranged on the wall surface of the primary support facing the buffer layer through a first fixing member, and the second end extends through the buffer layer towards the secondary lining and is fixed. The double-layer protection component is sleeved outside the measuring body and includes an inner protection sleeve and an outer protection sleeve nested with each other. One end of the inner protection sleeve is fixedly connected to the first fixing member, and the other end passes through the buffer layer and extends into the outer protection sleeve. And the inner protection sleeve slides in the outer protection sleeve along with the compression deformation of the buffer layer. One end of the outer protection sleeve is fixedly arranged on the wall surface of the buffer layer facing the secondary lining, and the other end extends towards the secondary lining and protrudes. Wherein, the second end of the measuring body is fixedly connected to the end of the outer protection sleeve away from the buffer layer through a second fixing member.

[0006] For example, in a device for measuring the compression amount of a tunnel yielding support buffer layer provided in an embodiment, a sealing ring is provided between the end of the inner protective sleeve away from the first fixing member and the inner wall of the outer protective sleeve.

[0007] For example, in a device for measuring the compression amount of a tunnel yielding support buffer layer provided in an embodiment, the inner protective sleeve is sleeved outside the measurement body, the outer protective sleeve is sleeved outside the inner protective sleeve, and the second end of the measurement body passes through the inner protective sleeve and extends into the outer protective sleeve.

[0008] For example, in a device for measuring the compression amount of a tunnel yielding support buffer layer provided in an embodiment, the measurement body is compressed as the buffer layer deforms, and the measuring range of the measurement body is not less than 1.5 times the designed yielding amount of the buffer layer.

[0009] For example, in a device for measuring the compression amount of a tunnel yielding support buffer layer provided in an embodiment, the measurement body is a wire rope displacement sensor, a multi-point displacement meter, a crack meter, a laser displacement sensor or a magnetostrictive sensor.

[0010] For example, in a device for measuring the compression amount of a tunnel yielding support buffer layer provided in an embodiment, the inner protective sleeve and the outer protective sleeve are of a cylindrical structure to provide a linear measurement channel for the measurement body.

[0011] For example, in a device for measuring the compression amount of a tunnel yielding support buffer layer provided in an embodiment, the length of the inner protective sleeve is less than the length of the outer protective sleeve, and the diameter of the inner protective sleeve is less than the diameter of the outer protective sleeve.

[0012] For example, in a device for measuring the compression amount of a tunnel yielding support buffer layer provided in an embodiment, the second end of the measurement body is fixed to the end of the outer protective sleeve away from the buffer layer by bolts or glue, or the second end of the measurement body is welded to the steel arch and the steel mesh.

[0013] For example, in a device for measuring the compression amount of a tunnel yielding support buffer layer provided in an embodiment, the first fixing member is fixed by being embedded in the initial support, or the first fixing member is fixed by expansion bolts after the initial support is completed, or the first fixing member is welded to the tunnel steel frame or the steel mesh.

[0014] The second aspect of the present application provides a construction method for a device for measuring the compression amount of a tunnel pressure-relieving support buffer layer, including the following steps: S1: Conduct initial support construction, fix the first fixing member, and install the measurement body and the inner protective sleeve at the first fixing member; S2: Conduct buffer layer construction; S3: Conduct secondary lining construction, install the outer protective sleeve, install a sealing ring between the end of the inner protective sleeve away from the first fixing member and the inner wall of the outer protective sleeve, and install a second fixing member at the end of the outer protective sleeve away from the buffer layer, and fixedly connect it to the second end of the measurement body; wherein, the measurement body is pre-stretched to the designed range and contracts as the buffer layer compresses during the compression process of the buffer layer.

[0015] The beneficial effects brought by a device for measuring the compression amount of a tunnel pressure-relieving support buffer layer and a construction method provided by some embodiments of the present application are as follows: The present application realizes the monitoring and measurement of the compression deformation amount of the tunnel buffer layer, provides a basis for the evaluation index and dynamic design of the buffer layer support effect, and overcomes the influence of the secondary lining pouring on the deformation amount measurement, ensuring the authenticity and accuracy of the measurement results. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present specification or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a schematic structural diagram of a device for measuring the compression amount of a tunnel pressure-relieving support buffer layer of the present application;

[0018] Figure 2 It is a cross-sectional view of a tunnel pressure-relieving support buffer layer of the present application;

[0019] Figure 3 It is a flowchart of a construction method for a device for measuring the compression amount of a tunnel pressure-relieving support buffer layer of the present application. Detailed Embodiments

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0021] Unless otherwise defined, the technical terms or scientific terms used in this disclosure shall have the ordinary meanings as understood by those of ordinary skill in the field to which this disclosure pertains. The terms "first", "second" and similar terms used in this disclosure do not denote any order, quantity or importance, but are only used to distinguish different components. The terms such as "comprising" or "including" mean that the elements or items appearing before this term cover the elements or items listed after this term and their equivalents, without excluding other elements or items. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left" and "right" are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationships may also change accordingly.

[0022] In a first aspect of the present application, there is provided a device 100 for measuring the compression amount of a tunnel yielding support buffer layer, as Figure 1 shown, which is used to measure the compression deformation amount of the buffer layer 400 located between the primary support 200 and the secondary lining 300, and to feedback the compression amount data to a storage device in real time. The device includes a measuring body 110 and a double-layer protection assembly 120. The measuring body 110 has a first end 111 and a second end 112. The first end 111 is fixedly arranged on the wall surface of the primary support 200 facing the buffer layer 400 through a first fixing member 113. The second end 112 extends through the buffer layer 400 towards the secondary lining 300 and is fixed. The double-layer protection assembly 120 is sleeved outside the measuring body 110 and includes an inner protection sleeve 121 and an outer protection sleeve 122 which are nested with each other. One end of the inner protection sleeve 121 is fixedly connected to the first fixing member 113, and the other end passes through the buffer layer 400 and extends into the outer protection sleeve 122. And the inner protection sleeve 121 slides in the outer protection sleeve 122 along with the compression deformation of the buffer layer 400. One end of the outer protection sleeve 122 is fixedly arranged on the wall surface of the buffer layer 400 facing the secondary lining 300, and the other end extends towards the secondary lining 300 and protrudes. Wherein, the second end 112 of the measuring body 110 is fixedly connected to the end of the outer protection sleeve 122 far from the buffer layer 400 through a second fixing member 114.

[0023] Specifically, as Figure 2 shown, under the action of the deformation of the tunnel surrounding rock, the primary support 200 is compressed and drives the buffer layer 400 to compress towards the secondary lining 300. The inner protection sleeve 121 slides towards the secondary lining 300 in the outer protection sleeve 122 along with the compression deformation of the buffer layer 400, and the measuring body 110 shrinks along with the compression of the buffer layer 400.

[0024] According to the above embodiments, by providing an inner protective sleeve 121 in the buffer layer 400 section, the measuring body 110 is protected from damage caused by external pressure, water, etc. in the primary support 200 and the buffer layer 400, and a straight measuring channel is provided for the measuring body 110 to prevent the measuring result from being distorted due to the bending of the measuring body 110; by providing an outer protective sleeve 122 in the secondary lining 300 section, the measuring body 110 is prevented from being affected by on-site construction, especially the pouring of the secondary lining, and the measuring body 110 can be compressed with the deformation of the surrounding rock within the outer protective sleeve 122 to prevent the measuring body 110 from being unable to move due to the solidification of concrete during the construction process; the first end 111 of the measuring body 110 is fixed by the first fixing member 113 to monitor the displacement of the buffer layer 400 near the secondary lining 300 side, and the second end 112 of the measuring body 110 is fixed by the second fixing member 114 to monitor the displacement of the buffer layer 400 near the primary support 200 side.

[0025] For example, in a tunnel yielding support buffer layer compression amount measuring device provided by an embodiment, as Figure 1 shown, a sealing ring 123 is provided between the end of the inner protective sleeve 121 away from the first fixing member 113 and the inner wall of the outer protective sleeve 122.

[0026] According to the above embodiments, by providing a sealing ring 123 between the end of the inner protective sleeve 121 and the inner wall of the outer protective sleeve 122, dust and water generated during the construction process are prevented from entering the inner protective sleeve 121, and the measuring body 110 is prevented from being damaged by the heat released during the hydration of concrete.

[0027] For example, in a tunnel yielding support buffer layer compression amount measuring device provided by an embodiment, as Figure 1 shown, the inner protective sleeve 121 is sleeved outside the measuring body 110, the outer protective sleeve 122 is sleeved outside the inner protective sleeve 121, and the second end 112 of the measuring body 110 passes through the inner protective sleeve 121 and extends into the outer protective sleeve 122.

[0028] For example, in a tunnel yielding support buffer layer compression amount measuring device provided by an embodiment, as Figure 1 shown, the measuring body 110 is compressed with the deformation of the buffer layer 400, and the measuring range of the measuring body 110 is not less than 1.5 times the designed yielding amount of the buffer layer 400.

[0029] For example, in a tunnel yielding support buffer layer compression amount measuring device provided by an embodiment, the measuring body 110 includes, but is not limited to, a wire-pulling sensor, a multi-point displacement meter, a crack gauge, a laser displacement sensor, or a magnetostrictive sensor, ensuring that the measuring body 110 has reliable accuracy, low cost, and good reliability.

[0030] For example, in the compression amount measuring device of the tunnel yielding support buffer layer provided in an embodiment, as Figure 1 shown, the inner protective sleeve 121 and the outer protective sleeve 122 are of a cylindrical structure to provide a linear measurement channel for the measurement body 110.

[0031] For example, in the compression amount measuring device of the tunnel yielding support buffer layer provided in an embodiment, as Figure 1 shown, the length of the inner protective sleeve 121 is less than that of the outer protective sleeve 122, and the diameter of the inner protective sleeve 121 is less than that of the outer protective sleeve 122.

[0032] Among them, the outer protective sleeve 122 should simulate the influence of the deformation of the outer protective sleeve 122 generated by the pouring of the secondary lining on its inner diameter through numerical simulation to prevent the measurement body 110 from being unable to move due to the solidification of concrete during the construction process. The outer protective sleeve 12 and the tunnel secondary lining 300 deform in coordination. The deformation amount of the tunnel secondary lining is extremely small relative to the deformation amount of the buffer layer and can be ignored.

[0033] For example, in the compression amount measuring device of the tunnel yielding support buffer layer provided in an embodiment, as Figure 1 shown, the second end 112 of the measurement body 110 is fixedly connected to the end of the outer protective sleeve 122 away from the buffer layer 400 by bolts or glue, or the second end 112 of the measurement body 110 is welded to the steel arch and the steel bar mesh.

[0034] For example, in the compression amount measuring device of the tunnel yielding support buffer layer provided in an embodiment, as Figure 1 shown, the first fixing member 113 is fixed by being embedded in the primary support 200, or the first fixing member 113 is fixed by expansion bolts after the primary support 200 is completed, or the first fixing member 113 is welded to the tunnel steel frame or the steel bar mesh.

[0035] Among them, when the first fixing member 113 is embedded in the primary support 200 or fixed by expansion bolts after the primary support 200 is completed, the displacement of the buffer layer 400 close to the secondary lining 300 side is monitored by being fixedly connected to the first end 110 of the measurement body 110; when the first fixing member 113 is welded to the tunnel steel frame or the steel bar mesh, the measurement principle is: the displacement of the tunnel steel frame or the steel bar mesh is equal to the displacement of the primary support 200 away from the tunnel inner wall side, and at the same time, the inner side displacement of the primary support 200 is equal to the displacement of the buffer layer 400 close to the secondary lining 30 side. Spot welding is used during welding; after welding, use a small wrench to tap the welding position to check whether it is firmly welded.

[0036] The compression amount measuring device for the tunnel yielding support buffer layer of the present application realizes the monitoring and measurement of the compression deformation amount of the tunnel buffer layer, provides a basis for the evaluation index and dynamic design of the buffer layer support effect, and overcomes the influence of the secondary lining pouring on the deformation amount measurement, ensuring the authenticity and accuracy of the measurement results.

[0037] The second aspect of the present application provides a construction method for a compression amount measuring device for a tunnel yielding support buffer layer, as Figure 3 shown, including the following steps:

[0038] S1. Construct the primary support 200, fix the first fixing member 113, and install the measurement body 110 and the inner protective sleeve 121 at the first fixing member 113;

[0039] S2. Construct the buffer layer 400;

[0040] S3. Construct the secondary lining 300, install the outer protective sleeve 122, install a sealing ring 123 between the end of the inner protective sleeve 121 away from the first fixing member 113 and the inner wall of the outer protective sleeve 122, and install a second fixing member 114 at the end of the outer protective sleeve 122 away from the buffer layer 400, and fixedly connect it to the second end 112 of the measurement body 110.

[0041] Among them, the measurement body 110 is pre-stretched to the designed range and shrinks as the buffer layer 400 compresses during the compression process of the buffer layer 400.

[0042] Specifically, as Figure 2As shown in the figure, the compression measurement device and construction method of the tunnel pressure-relieving support buffer layer of the present application are used to measure the compression of the pressure-relieving support buffer layer of a certain tunnel. Among them, the thickness of the initial support 200 of the tunnel is 20 cm, the thickness of the buffer layer 400 is 10 cm, and the thickness of the secondary lining 300 is 60 cm. A crack gauge is used to measure the deformation of the tunnel pressure-relieving support buffer layer 400. Through preliminary calculation, the deformation of the buffer layer 400 is obtained as 30 mm. Therefore, a crack gauge with a measuring range of 50 mm is selected. The diameter of the selected crack gauge is 26.5 mm, the diameter of the inner protective sleeve 121 is selected as 30 mm, and the diameter of the outer protective sleeve 122 is selected as 32 mm. The materials are all aluminum alloy. Through numerical simulation, the inner protective sleeve 121 can slide freely in the outer protective sleeve 122 after the construction of the secondary lining 300; when the initial support 200 is constructed, the first fixing piece 113 is buried, and then the measuring body 110 and the inner protective sleeve 121 are fixed by welding on the first fixing piece 113. The inner protective sleeve 121 is perpendicular to the initial support 200 and can measure the deformation of the buffer layer 400 along the thickness direction; then the construction of the buffer layer 300 is carried out, and during this period, attention should be paid to protecting the measuring body 110 and the inner protective sleeve 121 from being damaged; when the secondary lining 300 is constructed, the outer protective sleeve 122 and the sealing ring 123 are installed. The inner protective sleeve 121 is fastened to the outer protective sleeve 122 by screws. The outer protective sleeve 122 deforms synchronously with the secondary lining 300, so as to measure the actual deformation of the buffer layer 300.

[0043] Although the embodiments of the present application have been disclosed as above, they are not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present application. For those familiar with the field, other modifications can be easily achieved. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present application is not limited to the specific details and the illustrations shown and described here.

Claims

1. A measuring device for the compression amount of a tunnel pressure-relieving support buffer layer, characterized in that, Used for measuring the compression deformation of the buffer layer between the primary support and the secondary lining, including: A measuring body having a first end and a second end. The first end is fixedly arranged on the wall surface of the primary support facing the buffer layer through a first fixing member, and the second end extends through the buffer layer towards the secondary lining and is fixed; A double-layer protection assembly sleeved outside the measuring body, including an inner protection sleeve and an outer protection sleeve nested with each other. One end of the inner protection sleeve is fixedly connected to the first fixing member, and the other end passes through the buffer layer and extends into the outer protection sleeve. And the inner protection sleeve slides in the outer protection sleeve with the compression deformation of the buffer layer. One end of the outer protection sleeve is fixedly arranged on the wall surface of the buffer layer facing the secondary lining, and the other end extends towards the secondary lining and protrudes; Wherein, the second end of the measuring body is fixedly connected to the end of the outer protection sleeve far from the buffer layer through a second fixing member; A sealing ring is arranged between the end of the inner protection sleeve far from the first fixing member and the inner wall of the outer protection sleeve; The measuring body is compressed with the deformation of the buffer layer, and the measuring range of the measuring body is not less than 1.5 times of the designed yielding amount of the buffer layer.

2. The compression amount measuring device for the tunnel yielding support buffer layer according to claim 1, wherein The inner protection sleeve is sleeved outside the measuring body, the outer protection sleeve is sleeved outside the inner protection sleeve, and the second end of the measuring body passes through the inner protection sleeve and extends into the outer protection sleeve.

3. The compression amount measuring device for the tunnel yielding support buffer layer according to claim 1, characterized in that The measuring body is a wire-pulling sensor, a multi-point displacement meter, a crack gauge, a laser displacement sensor or a magnetostrictive sensor.

4. The compression amount measuring device for the tunnel yielding support buffer layer according to claim 1, characterized in that The inner protection sleeve and the outer protection sleeve are of a cylindrical structure to provide a linear measuring channel for the measuring body.

5. The compression amount measuring device for the tunnel yielding support buffer layer according to claim 4, characterized in that, The length of the inner protection sleeve is less than the length of the outer protection sleeve, and the diameter of the inner protection sleeve is less than the diameter of the outer protection sleeve.

6. The compression amount measuring device for the tunnel yielding support buffer layer according to claim 1, wherein, The second end of the measuring body is fixed to the end of the outer protection sleeve far from the buffer layer through bolts or glue, or the second end of the measuring body is welded to the steel arch and the steel bar mesh.

7. The compression amount measuring device for the tunnel yielding support buffer layer according to claim 1, characterized in that, The first fixing member is fixed by being embedded in the primary support, or the first fixing member is fixed by expansion bolts after the primary support is completed, or the first fixing member is welded to the tunnel steel frame or the steel bar mesh.

8. The construction method of the measuring device for the compression amount of the tunnel yielding support buffer layer according to any one of claims 1-7, characterized in that Including the following steps: S1: Construct the primary support, fix the first fixing member, and install the measuring body and the inner protection sleeve at the first fixing member; S2: Construct the buffer layer; S3: Construct the secondary lining, install the outer protection sleeve, install a sealing ring between the end of the inner protection sleeve far from the first fixing member and the inner wall of the outer protection sleeve, install a second fixing member at the end of the outer protection sleeve far from the buffer layer, and fixedly connect it to the second end of the measuring body; Wherein, the measuring body is pre-stretched to the designed measuring range and contracts with the compression of the buffer layer during the compression process of the buffer layer.

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