A kind of tunnel model segment local transverse expansion force quantitative loading mechanism

Abstract

The application discloses a kind of tunnel model segment local transverse expansion force quantitative loading mechanism, including hard arc plate, spring dynamometer, pivot, rotating handle, limiting plate, limiting cylinder, locking screw and mounting bracket, the lower end of pivot is inserted into the limiting hole of limiting plate, and the upper end passes through limiting cylinder, rotating handle is installed in the upper end of pivot, the cylinder wall of limiting cylinder is equipped with screw hole and locking screw is installed in the screw hole, hard arc plate is placed outside tunnel model segment and with face face contact, the upper end and the lower end of hard arc plate are connected with the one end of spring dynamometer respectively by connecting piece, the other end of spring dynamometer is connected with pivot.The application can realize the loading of tunnel model segment local transverse expansion force by rotating rotating handle, and keep stable by locking screw locking, determine the loading force size by spring dynamometer, realize quantitative loading purpose, facilitate quantitative analysis expansion force and the interaction and deformation relationship of tunnel model segment.

Description

Technical Field

[0001] This invention relates to an expansion force loading mechanism for tunnel models, and more particularly to a quantitative loading mechanism for local lateral expansion force of tunnel model segments, belonging to the field of tunnel model research. Background Technology

[0002] The shield tunneling method plays a vital role in modern tunnel construction, particularly in projects such as urban subways, integrated utility tunnels, and large underwater tunnels. Tunnels constructed using shield tunneling equipment are subject to long-term soil expansion pressure. To ensure tunnel safety, it is necessary to simulate various real-world environments using tunnel models, thereby researching methods to ensure safe tunnel construction and use.

[0003] A tunnel model segment is a device that simulates the lining structure of a tunnel. It is cylindrical in shape and filled with soil. The soil is placed inside a soil box, and the box plate is connected to a jack to form an expansion force loading device for tunnel simulation tests.

[0004] In actual construction, one may encounter soils with expansive properties, such as mudstone and silty mudstone, which all possess expansive characteristics. Expansive rocks are a special type of soft rock, exhibiting properties that are neither rock nor soil, and they are extremely closely related to water, exhibiting exceptionally strong hydrophilicity. Due to their high content of hydrophilic minerals, they undergo significant volume changes with variations in humidity, and generate substantial internal stress when deformation is constrained.

[0005] To simulate the above-mentioned expansive soil application environment, it is necessary to apply local lateral expansion force to the tunnel model segments. The traditional loading method is to place equivalent expansive soil with expansive properties around the tunnel model segments and qualitatively simulate the expansion load of the expansive rock layer on the segments by controlling the mix ratio and water content.

[0006] While the aforementioned traditional loading method can achieve the loading of local lateral expansion forces on tunnel model segments in experiments, it also has the following drawbacks:

[0007] Only qualitative loading can be performed, not quantitative loading. That is, the specific magnitude of the loading force cannot be determined because it is difficult to measure the magnitude of the expansion force applied to the tunnel segment when an appropriate amount of expansive soil is added. Therefore, it is difficult to quantitatively analyze the interaction and deformation relationship between the expansion force and the tunnel model segment. Summary of the Invention

[0008] The purpose of this invention is to provide a quantitative loading mechanism for the local lateral expansion force of tunnel model segments in order to solve the above-mentioned problems.

[0009] The present invention achieves the above objectives through the following technical solutions:

[0010] A quantitative loading mechanism for local lateral expansion force of a tunnel model segment is disclosed. A pressure plate is positioned above the cylindrical tunnel model segment with a vertical central axis. A central through-hole is located at the center of the pressure plate. The outer diameter of the tunnel model segment is smaller than the diameter of the central through-hole. The mechanism includes a rigid arc-shaped plate, a spring force gauge, a rotating shaft, a rotating handle, a limiting plate, a limiting cylinder, locking screws, and a mounting bracket. The limiting plate is installed in the lower part of the tunnel model segment and has a limiting hole. The limiting cylinder, with a vertical central axis, is mounted on the pressure plate via the mounting bracket and is located directly above the tunnel model segment. The lower end of the vertical rotating shaft is inserted into the limiting hole. The upper end of the rotating shaft passes through the central through hole of the limiting cylinder from bottom to top. The rotating handle is installed on the upper end of the rotating shaft. The cylinder wall of the limiting cylinder is provided with a horizontal screw hole and the locking screw is installed in the screw hole. The curvature of the rigid arc plate is the same as that of the tunnel model segment. The rigid arc plate is placed outside the tunnel model segment and contacts the outer wall surface of the tunnel model segment. The upper and lower ends of the rigid arc plate are respectively connected to one end of the horizontal spring force gauge through connecting parts. The other end of the spring force gauge is connected to the rotating shaft through a metal wire or pull rope (preferably a metal wire). The spring force gauge is located between the inner wall of the tunnel model segment and the rotating shaft and corresponds to the vertical middle section of the tunnel model segment.

[0011] Preferably, in order to facilitate the direct connection between the rigid arc plate and the connectors without being affected by the tunnel model segments, the vertical height of the rigid arc plate is higher than that of the tunnel model segments. The middle of the upper end and the middle of the lower end of the rigid arc plate are bent inward toward the tunnel model segments to form connecting parts. One end of each of the two connectors is connected to the two connecting parts, and the other end of each connector is connected to one end of the spring force gauge.

[0012] Specifically, the connector is a rigid connecting rod, metal wire, or connecting rope, preferably a rigid connecting rod, such as an iron bar, which can be welded to a rigid curved plate (such as an iron plate) to achieve better force transmission.

[0013] Preferably, for ease of connection and better force transmission, the rigid arc plate is made of iron, and the spring force gauge is connected to the rotating shaft by iron wire.

[0014] Preferably, in order to achieve quantitative loading of expansion force at any position in the circumference of the tunnel model segment, the centerline of the rotating shaft coincides with the centerline of the tunnel model segment.

[0015] Preferably, to facilitate a faster understanding of the applied force, the spring balance is an electronic spring balance.

[0016] The beneficial effects of this invention are as follows:

[0017] This invention utilizes a design that incorporates a rigid arc-shaped plate, a spring force gauge, a rotating shaft, a rotating handle, a limiting plate, a limiting cylinder, a locking screw, and a mounting bracket. By rotating the handle, local lateral expansion force can be applied to the tunnel model segments, and the locking screw ensures stability. The spring force gauge quickly determines the magnitude of the applied force, thus achieving quantitative loading and facilitating quantitative analysis of the interaction and deformation relationship between the expansion force and the tunnel model segments. This mechanism is easy to assemble and disassemble, simple and reliable to use, and does not affect the overall expansion force loading device in tunnel simulation tests. It is reusable and can meet the quantitative loading requirements of local lateral expansion force under various working conditions and combinations of working conditions. Attached Figure Description

[0018] Figure 1 This is a top view of the overall expansion force loading device, including the local lateral expansion force quantitative loading mechanism for tunnel model segments as described in this invention.

[0019] Figure 2 This is a top view schematic diagram of the quantitative loading mechanism for local lateral expansion force of tunnel model segments according to the present invention;

[0020] Figure 3 This is a top view of the tunnel model segment local lateral expansion force quantitative loading mechanism described in this invention, and a cross-sectional view along the AA direction. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings:

[0022] like Figure 1 As shown, the overall expansion force loading device for tunnel simulation test includes a base 1, a soil box 3, and jacks 2. A pressure plate 4 is provided on the top of the soil box 3, and a central through hole 40 is provided at the center of the pressure plate 4. A cylindrical tunnel model segment 5 with a vertical central axis is located below the pressure plate 4. The outer diameter of the tunnel model segment 5 is smaller than the diameter of the central through hole 40 of the pressure plate. Multiple jacks 2 apply pressure from the front, back, left, right, and top to simulate soil expansion force. The soil box 3 is filled with soil. The local transverse expansion force quantitative loading mechanism 6 of the tunnel model segment described in this invention is installed in the middle of the overall expansion force loading device.

[0023] like Figures 2-3As shown, the local lateral expansion force quantitative loading mechanism 6 of the tunnel model segment of the present invention includes a rigid arc plate 64, a spring force gauge 66, a rotating shaft 63, a rotating handle 61, a limiting plate 60, a limiting cylinder 62, a locking screw 68, and a mounting bracket 69. The limiting plate 60 is installed in the lower part of the tunnel model segment 5 by the mounting screw 600. The limiting plate 60 is provided with a limiting hole (not shown in the figure). The limiting cylinder 62, whose central axis is vertical, is installed on the pressure plate 4 by the mounting bracket 69 (the mounting bracket 69 is connected to the hole wall of the central through hole 40 of the pressure plate) and is located in the tunnel model segment 5. Directly above, the lower end of the vertical rotating shaft 63 is inserted into the limiting hole, and the upper end of the rotating shaft 63 passes through the central through hole of the limiting cylinder 62 from bottom to top. The rotating handle 61 is installed on the upper end of the rotating shaft 63. The cylinder wall of the limiting cylinder 62 is provided with a horizontal screw hole (not shown in the figure) and the locking screw 68 is installed in the screw hole. The curvature of the rigid arc plate 64 is the same as the curvature of the tunnel model tube segment 5. The rigid arc plate 64 is placed outside the tunnel model tube segment 5 and contacts the outer wall surface of the tunnel model tube segment 5. The upper and lower ends of the rigid arc plate 64 are respectively connected to one end of the horizontal spring force gauge 66 through the connector 65. The other end of the spring force gauge 66 is connected to the rotating shaft 63 through the metal wire 67 (or the pull rope). The spring force gauge 66 is located between the inner wall of the tunnel model tube segment 5 and the rotating shaft 63 and corresponds to the vertical middle section of the tunnel model tube segment 5.

[0024] As a preferred option, such as Figure 3 As shown, to facilitate the direct connection between the rigid arc plate 64 and the connector 65 without being affected by the tunnel model segment 5, the vertical height of the rigid arc plate 64 is higher than that of the tunnel model segment 5. The upper middle part and the lower middle part of the rigid arc plate 64 are bent towards the interior of the tunnel model segment 5 to form a connecting part 640. One end of the two connectors 65 is connected to the two connecting parts 640 respectively, and the other end of the two connectors 65 is connected to one end of the spring force gauge 66. The connector 65 is a rigid connecting rod, metal wire or connecting rope, preferably a rigid connecting rod, such as an iron bar. The rigid arc plate 64 is an iron plate, and the spring force gauge 66 is connected to the rotating shaft 63 by an iron wire, that is, the metal wire 67 is an iron wire. The center line of the rotating shaft 63 coincides with the center line of the tunnel model segment 5. The spring force gauge 66 is an electronic spring force gauge.

[0025] like Figures 1-3As shown, during the test, expansion force is applied according to the specific working conditions. To determine which local area of ​​the tunnel model segment 5 requires lateral expansion force, the rigid arc plate 64 is moved to that area. The locking screw 68 is loosened, and the rotating handle 61 is turned, causing the metal wire 67 to wind around the rotating shaft 63. Simultaneously, the spring force gauge 66 is pulled. The spring force gauge 66 transmits the tension to the rigid arc plate 64 through the connecting piece 65, causing the rigid arc plate 64 to apply lateral pressure to the corresponding area of ​​the tunnel model segment 5, thus simulating lateral expansion force. Furthermore, because the rigid arc plate 64 cannot push the tunnel model segment 5, the spring force gauge 66 is stretched and displays the tension magnitude. The operator compares the displayed tension magnitude with the preset expansion force magnitude. When the two are the same or close, the rotating shaft 63 is stopped, and the locking screw 68 is rotated to lock the rotating shaft 63. At this point, the quantitative loading of the local lateral expansion force on the tunnel model segment 5 is completed.

[0026] When conducting the next test, loosen the locking screw 68, rotate the shaft 63 in the opposite direction to fully reset the spring balance 66, and then move the rigid arc plate 64 to the corresponding local area of ​​the tunnel model segment 5 as needed. Repeat the above process to achieve a similar quantitative loading.

[0027] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the technical solutions of the present invention. Any technical solution that can be implemented based on the above embodiments without creative effort should be considered to fall within the scope of protection of the patent of the present invention.

Claims

1. A quantitative loading mechanism for local lateral expansion force of a tunnel model segment, wherein a pressure plate is provided above the cylindrical tunnel model segment with a vertical central axis, and a central through hole is provided at the center of the pressure plate, the outer diameter of the tunnel model segment being smaller than the diameter of the central through hole of the pressure plate, characterized in that: The tunnel model segment local transverse expansion force quantitative loading mechanism comprises a hard arc plate, a spring dynamometer, a rotating shaft, a rotating handle, a limiting plate, a limiting cylinder, a locking screw and a mounting bracket, the limiting plate is mounted at the lower part in the tunnel model segment, the limiting plate is provided with a limiting hole, the limiting cylinder with a vertical central axis is mounted on the pressing plate through the mounting bracket and located directly above the tunnel model segment, the lower end of the vertical rotating shaft is inserted into the limiting hole, the upper end of the rotating shaft passes through the central through hole of the limiting cylinder from bottom to top, the rotating handle is mounted on the upper end of the rotating shaft, the cylinder wall of the limiting cylinder is provided with a transverse screw hole and the locking screw is mounted in the screw hole, the arc of the hard arc plate is the same as the arc of the tunnel model segment, the hard arc plate is placed outside the tunnel model segment and in surface contact with the outer wall surface of the tunnel model segment, the upper end and the lower end of the hard arc plate are connected with one end of the transverse spring dynamometer through connecting pieces respectively, the other end of the spring dynamometer is connected with the rotating shaft through a metal wire or a pull rope, the spring dynamometer is located between the inner wall of the tunnel model segment and the rotating shaft and corresponds to the vertical middle segment of the tunnel model segment; the vertical height of the hard arc plate is higher than the vertical height of the tunnel model segment, the upper middle part and the lower middle part of the upper end and the lower end of the hard arc plate are respectively bent to form connecting parts in the direction of the inside of the tunnel model segment, one end of two connecting pieces is connected with two connecting parts respectively, and the other end of two connecting pieces is connected with one end of the spring dynamometer.

2. The mechanism for quantitatively loading the local transverse expansion force of the tunnel model segment according to claim 1, characterized in that: The connecting piece is a hard connecting rod, a metal wire or a connecting rope.

3. The mechanism for quantitatively loading the local transverse expansion force of the tunnel model segment according to claim 1 or 2, characterized in that: The hard arc plate is an iron plate, the spring dynamometer and the rotating shaft are connected through an iron wire.

4. The mechanism for quantitatively loading the local transverse expansion force of the tunnel model segment according to claim 1 or 2, characterized in that: The central line of the rotating shaft coincides with the central line of the tunnel model segment.

5. The mechanism for quantitatively loading the local transverse expansion force of the tunnel model segment according to claim 1 or 2, characterized in that: The spring dynamometer is an electronic spring dynamometer.

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