Monitoring device for rock surrounding soil pressure of highway tunnel

Abstract

The utility model discloses a road tunnel surrounding rock soil pressure monitoring device. The device comprises a soil pressure box; the supporting ring is arranged on the soil pressure box in a sleeving manner; the supporting ring is arranged on the assembling side of the base plate; the supporting rods are arranged on the non-assembling side of the base plate; spherical lap joint blocks are arranged at the four corners of the connecting plate. The spherical lap joint blocks at the four corners of the connecting plate freely move in the sliding grooves in the four supporting rods, and the relative position and angle of the connecting plate can be freely changed according to the surrounding rock structure at the designated position, so that the connecting plate is tightly attached to supporting structures such as an arch frame under the condition that the top earth pressure box is tightly attached to the surrounding rock; more stable monitoring conditions are provided for the earth pressure cell, and the monitoring stability is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel monitoring equipment, and the main body is an earth pressure monitoring device based on a rock surrounding rock tunnel, in particular to a monitoring device for the earth pressure of a highway tunnel surrounding rock. Background Technique

[0002] To ensure the construction safety of highway tunnels during the construction period, the monitoring of the earth pressure of the surrounding rock has become one of the important means for tunnel monitoring during the construction period.

[0003] The vibrating wire earth pressure cell is one of the most commonly used earth pressure monitoring devices at present. The change in the stress of the vibrating wire inside the earth pressure cell will cause a corresponding change in its natural vibration frequency. Therefore, by measuring the change in the vibrating wire frequency, the change in the pressure received by the diaphragm of the pressure cell can be known, and then the corresponding earth pressure value can be obtained by combining the corresponding conversion formula.

[0004] When burying the earth pressure cell in the tunnel, it is generally necessary to ensure that one side surface of the earth pressure cell is in close contact with the surrounding rock. Usually, the surface of the earth pressure cell is perpendicular to the direction of the surrounding rock pressure to obtain the best monitoring effect. However, for rock tunnels, the exposed surface of the surrounding rock is generally not smooth under the action of blasting and extends at a specific angle. Therefore, there is often a situation where the earth pressure cell cannot be stably fixed after being attached to the surrounding rock, resulting in inaccurate measurement results. In addition, affected by the overexcavation of the tunnel, when the earth pressure cell is in close contact with the surrounding rock, it is difficult to fix the other surface of the earth pressure cell.

[0005] The prior art CN220473194U discloses a fixed installation bracket for an earth pressure cell. A steel bar ring is provided on the bottom plate, and the area inside this steel bar ring is the area for assembling the earth pressure cell, so that the earth pressure cell located inside the steel bar ring can be firmly fixed on the bottom plate. The steel bar ring is fixed on the bottom plate to enhance the connection strength between the earth pressure cell and the steel plate, preventing displacement or deformation during the measurement process. One end of two groups of support components is respectively vertically fixed on the other assembly surface of the bottom plate, and the distance between these two steel bars is approximately equal to the diameter of the earth pressure cell to ensure that the earth pressure cell can be stably placed on the bottom plate. In addition, the positions of the two parallel vertical steel bars welded on the bottom plate are close to the edge, thereby enhancing the stability of the entire bracket structure.

[0006] The prior art CN221222042U discloses a fixing device for ensuring uniform stress on a tunnel earth pressure cell, which includes a force - transfer plate Ⅰ, a force - transfer plate Ⅱ, a force - transfer plate Ⅲ, and a force - transfer plate Ⅳ that are all square. The force - transfer plate Ⅰ and the force - transfer plate Ⅳ are both in contact with the tunnel surrounding rock surface and the tunnel primary lining surface; the top of the force - transfer plate Ⅱ is connected to the force - transfer plate Ⅰ, and the bottom is in contact with one side of the earth pressure cell, and the other side of this earth pressure cell is in contact with the top of the force - transfer plate Ⅲ; the bottom of the force - transfer plate Ⅲ is connected to the force - transfer plate Ⅳ; rubber retaining rings are wrapped between the force - transfer plate Ⅰ and the force - transfer plate Ⅱ, and between the force - transfer plate Ⅲ and the force - transfer plate Ⅳ; solid smooth metal rods are provided at the four corners of the force - transfer plate Ⅱ; hollow smooth metal rods are provided at the four corners of the force - transfer plate Ⅲ, and solid smooth metal rods are sleeved inside the hollow smooth metal rods.

[0007] The prior art CN217084438U discloses an earth pressure cell fixing device, which includes a mounting base. A telescopic device is arranged on the mounting base, and a fixing tray for fixing the earth pressure cell is arranged at the front end of the telescopic device; the mounting base includes a first mounting arm and a second mounting arm. A chute is arranged on the first mounting arm, and the second mounting arm is slidably arranged in the chute; the telescopic device includes a sliding rod and a sleeve rod. One end of the sliding rod is connected to the mounting base, and the other end of the sliding rod is movably inserted into the sleeve rod. A fixing piece for limiting and fixing is arranged between the sliding rod and the sleeve rod; the fixing tray includes a tray base, the tray base is connected to the front end of the sleeve rod through a spherical joint, and a chassis for placing the earth pressure cell and a clamping mechanism for clamping and fixing the earth pressure cell are arranged on the tray base.

[0008] Although the above - mentioned prior art has improved the installation stability and stress uniformity of the earth pressure cell to a certain extent, when facing the protruding and irregular rock surfaces caused by surrounding rock blasting commonly found in rock tunnels, it is still difficult to achieve the close fitting of the earth pressure cell with the surrounding rock and the other support structure at the designated position simultaneously, and the measurement of earth pressure is unstable.

[0009] Therefore, it is necessary to provide a monitoring device for the earth pressure of highway tunnel surrounding rock to solve the above - mentioned technical problems. Utility Model Content

[0010] The utility model overcomes the deficiencies of the prior art and provides a monitoring device for the earth pressure of highway tunnel surrounding rock to achieve stable measurement of earth pressure.

[0011] To achieve the above - mentioned purpose, the technical solution adopted by the utility model is: A monitoring device for the earth pressure of highway tunnel surrounding rock, including:

[0012] An earth pressure cell;

[0013] A support ring sleeved on the earth pressure cell;

[0014] A backing plate, and the support ring is arranged on the assembly side of the backing plate;

[0015] A plurality of support rods, and a plurality of the support rods are arranged on the non-assembly side of the backing plate;

[0016] A connecting plate, and spherical lap joints are arranged at the four corners of the connecting plate;

[0017] Wherein, the support rod includes: a chute opened inside the support rod, and a plurality of clamping grooves arranged at intervals on the inner wall of the chute;

[0018] In the adjustable state of the device, the spherical lap joint slides along the axial direction of the chute;

[0019] In the fixed state of the device, the connecting plate is attached to the steel arch or steel mesh of the tunnel support structure, and an iron fixing piece is inserted into the clamping groove, and the spherical lap joint is locked at a preset position by welding.

[0020] In a preferred embodiment of the present invention, a wire groove is opened on the side wall of the support ring, and the lead wire of the earth pressure cell is led out through the wire groove and connected to an external monitoring system.

[0021] In a preferred embodiment of the present invention, the opening of the chute faces the inner side of the support rod, and the cross-sectional radius of the chute is larger than the radius of the spherical lap joint.

[0022] In a preferred embodiment of the present invention, the backing plate has a circular structure, and the connection points of a plurality of the support rods and the backing plate are equally angularly distributed along the circumference of the backing plate, and the included angle between adjacent connection points is 90°.

[0023] In a preferred embodiment of the present invention, the contact surfaces between the inner walls of the clamping grooves and the iron fixing pieces are all rough surfaces.

[0024] In a preferred embodiment of the present invention, the iron fixing piece has a circular thin plate structure.

[0025] In a preferred embodiment of the present invention, the connection positions of a plurality of the support rods and the backing plate are located in the area 0-2 cm inward from the edge of the backing plate.

[0026] In a preferred embodiment of the present invention, a plurality of the clamping grooves are equally spaced along the axial direction of the support rod.

[0027] In a preferred embodiment of the present invention, the length of the support rod is determined according to the reserved deformation amount in the tunnel design.

[0028] In a preferred embodiment of the present invention, in the adjustable state of the device, the connecting plate moves along the axial direction of the support rod.

[0029] The utility model solves the defects existing in the background technology and has the following beneficial effects:

[0030] (1) The utility model provides a monitoring device for the surrounding rock earth pressure of a highway tunnel, enabling one side surface of the earth pressure cell to closely adhere to the surrounding rock, and the other side to be closely attached and fixed by support structures such as steel reinforcement meshes and steel arches. The spherical lap joints at the four corners of the connecting plate can freely move within the internal chutes of the four support rods, and the relative position and angle of the connecting plate can be freely changed according to the surrounding rock structure at the designated position, so that the connecting plate can also be closely attached to the support structures such as the arch frame while the earth pressure cell at the top closely adheres to the surrounding rock, providing a more stable monitoring condition for the earth pressure cell and improving the monitoring stability.

[0031] (2) The utility model can meet the measurement requirements of the surrounding rock earth pressure of the tunnel under different overbreak and underbreak conditions. Since the lengths of the four support rods are related to the reserved deformation amount of the tunnel, and the position of the connecting plate can move along the axial direction of the support rod, the stable placement of the earth pressure cell can be achieved according to the current blasting excavation situation of the tunnel.

[0032] (3) The utility model is easy to install. After determining the installation position of the earth pressure cell, the position of the connecting plate can be initially determined by using a circular iron fixing piece, and then the positions of the connecting plate, the tunnel steel reinforcement, and the fixing piece can be further reinforced by welding to achieve the stable installation of the earth pressure cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The following further illustrates the utility model in conjunction with the drawings and embodiments;

[0034] Figure 1 is a three-dimensional structure diagram of a preferred embodiment of the utility model;

[0035] Figure 2 is a top view structure diagram of a preferred embodiment of the utility model;

[0036] Figure 3 is a top view structure diagram of the connecting plate of a preferred embodiment of the utility model;

[0037] Figure 4 is a top view structure diagram of the support ring of a preferred embodiment of the utility model;

[0038] Figure 5 is a structure diagram of the iron fixing piece of a preferred embodiment of the utility model;

[0039] Figure 6 is an installation schematic diagram of a preferred embodiment of the utility model.

[0040] In the figure: 1. Earth pressure cell; 2. Support ring; 3. Backing plate; 4. Support rod; 5. Connection plate; 41. Chute; 42. Card slot; 43. Iron fixing piece; 51. Spherical lap block; 6. Wire groove; 7. Lead wire. Detailed implementation mode

[0041] Now, the present utility model will be further described in detail with reference to the accompanying drawings and embodiments. These drawings are all simplified schematic diagrams, only showing the basic structure of the present utility model in a schematic way, so they only show the components related to the present utility model.

[0042] In a highway tunnel, a steel mesh and a steel arch are used as the initial support system. Through combined force, the deformation of the surrounding rock is controlled, the support stiffness is enhanced, the surrounding rock is quickly stabilized, and a basic support is provided for the subsequent secondary lining. The earth pressure refers to the force exerted by the soil on a building or structure. In this embodiment, it specifically refers to the force exerted by the surrounding rock soil of the tunnel on the support structure.

[0043] When the present utility model monitors the earth pressure of the surrounding rock, one side surface of the earth pressure cell is closely attached to the surrounding rock, and the other side is fixed by closely attaching to support structures such as a steel mesh and a steel arch to ensure the stable installation of the device and provide a more stable monitoring condition for the earth pressure cell.

[0044] As Figure 1 shown, a monitoring device for the earth pressure of the surrounding rock in a highway tunnel includes: an earth pressure cell 1, a support ring 2, a backing plate 3, a plurality of support rods 4 and a connection plate 5.

[0045] Among them, the earth pressure cell 1 is an instrument used for measuring the internal stress of the medium in geotechnical engineering, as well as the contact stress between the surrounding rock and the support structure, and between the shotcrete and the cast-in-place concrete. Among them, the surrounding rock refers to the surrounding rock mass whose stress state changes due to excavation in a rock underground project. It should be noted that the pressure cell used for monitoring the earth pressure between the surrounding rock and the support is also called the earth pressure cell 1.

[0046] As Figure 1 and Figure 4 shown, the support ring 2 is arranged on one assembly surface of the backing plate 3. The support ring 2 is a circular ring structure and is sleeved on the earth pressure cell 1 to ensure the stability of the position of the earth pressure cell 1. The size of the earth pressure cell 1 should be adapted to the size of the support ring 2. A wire groove 6 is opened on the side wall of the support ring 2, and the lead wire 7 of the earth pressure cell 1 is led out through the wire groove 6 and connected to an external monitoring system.

[0047] The backing plate 3 in this embodiment is circular, and 4 support rods 4 are arranged at the non-assembly side edge position of the backing plate 3. The top of the support rod 4 is welded and fixed to the surface of the backing plate 3.

[0048] As Figure 2 and Figure 3As shown, the connecting plate 5 is a square plate structure, and spherical lapping blocks 51 are provided at its four corners.

[0049] As Figure 1 and Figure 5 shown, the support rod 4 further includes: a quasi-cylindrical chute 41 opened inside the support rod 4, and a plurality of card slots 42 spaced on the inner wall of the chute 41. The plurality of card slots 42 are equidistantly distributed along the axial direction of the support rod 4. The card slots 42 have a certain depth for inserting a circular iron fixing piece 43 and can maintain temporary stability to fix the position of the spherical lapping block 51 in the chute 41.

[0050] It should be noted that the contact surfaces between the inner walls of the card slots 42 and the iron fixing piece 43 are all rough surfaces formed by sandblasting to improve the stability when the iron fixing piece 43 is inserted.

[0051] The utility model has two working states, including:

[0052] In the adjustable state of the device, the spherical lapping block 51 slides axially along the chute 41, that is, the 4 spherical lapping blocks 51 of the connecting plate 5 freely move in the chutes 41 inside the 4 support rods 4 to change the relative position and angle of the connecting plate 5.

[0053] In the fixed state of the device, the connecting plate 5 is attached to the steel arch or steel mesh of the tunnel support structure, and an iron fixing piece 43 is inserted into the card slot 42, and the spherical lapping block 51 is locked at a preset position by welding.

[0054] The spherical lapping blocks at the four corners of the connecting plate 5 of the utility model can freely move in the chutes 41 inside the 4 support rods, and the relative position and angle of the connecting plate 5 can be freely changed according to the surrounding rock structure at the specified position, so that the connecting plate 5 is also closely attached to the support structure such as the arch when the top earth pressure cell 1 is close to the surrounding rock, giving the earth pressure cell 1 more stable monitoring conditions and improving the monitoring stability.

[0055] In this embodiment, the support rod 4 is perpendicular to the backing plate 3 during welding, and the connection points of the 4 support rods 4 and the backing plate 3 are equally angularly distributed along the circumference of the backing plate 3, and the included angle between adjacent connection points is 90°. The connection position of the support rod 4 and the backing plate 3 is located in the area 0 - 2 cm inward from the edge of the backing plate 3, that is, as close as possible to the edge of the backing plate 3, but not exceeding the range of the backing plate 3. The length of the support rod 4 is determined according to the reserved deformation amount in the tunnel design to prevent the support rod 4 from being unable to be welded to the tunnel primary support steel mesh.

[0056] The opening of the sliding groove 41 faces the inner side of the support rod 4. The inner cross-section of the sliding groove 41 is circular, and the cross-sectional radius of the sliding groove 41 is larger than the radius of the spherical lap joint 51, preventing the spherical lap joint 51 from sliding out of the clamping groove 42, so that the connecting plate 5 can be adjusted arbitrarily in position and angle in the support rod 4. At the same time, the inner cross-sectional radius of the sliding groove 41 should be smaller than the radius of the support rod.

[0057] Figure 6 Fig. shows the installation schematic diagram of the present invention. Among them, the outer ring is the tunnel surrounding rock, and the inner ring cross-shaped structure is a steel arch or a steel mesh. When the present invention is used, first, according to the spatial dimensions between the on-site surrounding rock and the support structure such as a steel arch or a steel mesh, a spacer 3 with appropriate dimensions is selected to ensure that the earth pressure cell 1 and the support ring 2 arranged around it can be stably placed on the spacer 3 and the overall structure is kept stable.

[0058] Since the distance between the tunnel surrounding rock and the steel arch or the steel mesh is usually small, the connecting plate 5 should be adjusted to a position close to the spacer 3 in the initial state to adapt to the limitation of the installation space. If the device needs to be installed on a steel arch, the whole device should be spanned and placed above the steel arch first, and then subsequent adjustment operations are carried out.

[0059] Subsequently, the earth pressure cell 1 is fixed firmly in the support ring 2 by pasting or other fixing methods, and its lead wire 7 is led out along the wire groove 6 opened on the side wall of the support ring 2 for connection to an external monitoring system.

[0060] Next, it is preferred that one side of the earth pressure cell 1 is in close contact with the surface of the surrounding rock, and then the relative positions between the connecting plate 5 and the steel arch or the steel arch are adjusted as a whole, so that the connecting plate 5 is in contact with the surface of the support structure as much as possible. If the connecting plate 5 is not completely attached at this time, the positions of the four spherical lap joints 51 in the corresponding sliding grooves 41 of the support rod 4 can be adjusted respectively until a good contact state is achieved; then an iron fixing piece 43 is inserted into the corresponding clamping groove 42, and the spherical lap joint 51 is locked in the set position by welding to complete the fixation.

[0061] If the connecting plate 5 is basically attached to the surface of the support structure, welding fixation can be directly carried out without additional adjustment of the spherical lap joint 51.

[0062] Finally, depending on the on-site installation situation, if necessary, the part of the support rod 4 that exceeds the actual required length can be cut off to improve the overall compactness and safety of the device, thus completing the installation process of the entire monitoring device.

[0063] Compared with the traditional fixing device of the earth pressure cell 1, since the four spherical lapping blocks 51 on the connecting plate 5 can all move, it can better adapt to the installation conditions of the complex extension structural plane of the tunnel surrounding rock, and flexibly adjust the installation attitude of the earth pressure cell 1 according to the actual environment and install it stably. This can not only ensure the accuracy of the tunnel monitoring data, but also facilitate the installation of on-site construction personnel and further improve the survival rate of the earth pressure cell 1.

[0064] Based on the ideal embodiments of the present utility model as inspiration, through the above description, relevant personnel can completely make various changes and modifications without departing from the technical idea of this utility model. The technical scope of this utility model is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A monitoring device for the surrounding rock pressure of a highway tunnel, characterized in that, Comprising: Earth pressure cell (1); Support ring (2), sleeved on the earth pressure cell (1); Backing plate (3), the support ring (2) is arranged on the assembly side of the backing plate (3); A plurality of support rods (4), a plurality of the support rods (4) are arranged on the non-assembly side of the backing plate (3); Connecting plate (5), spherical lap joints (51) are arranged at the four corners of the connecting plate (5); Wherein, the support rod (4) includes: a chute (41) opened inside the support rod (4), and a plurality of clamping grooves (42) spaced apart on the inner wall of the chute (41); In the adjustable state of the device, the spherical lap joint (51) slides along the axial direction of the chute (41); In the fixed state of the device, the connecting plate (5) fits against the steel arch or steel mesh of the tunnel support structure, and an iron fixing piece (43) is inserted into the clamping groove (42), and the spherical lap joint (51) is locked at a preset position by welding.

2. The monitoring device for the surrounding rock pressure of a highway tunnel according to claim 1, characterized in that: A wire groove (6) is opened on the side wall of the support ring (2), and the lead wire (7) of the earth pressure cell (1) is led out through the wire groove (6) and connected to an external monitoring system.

3. The monitoring device for the surrounding rock pressure of a highway tunnel according to claim 1, characterized in that: The opening of the chute (41) faces the inner side of the support rod (4), and the cross-sectional radius of the chute (41) is larger than the radius of the spherical lap joint (51).

4. The monitoring device for the surrounding rock pressure of a highway tunnel according to claim 1, characterized in that: The backing plate (3) has a circular structure, and the connection points of the plurality of support rods (4) and the backing plate (3) are equally angularly distributed along the circumference of the backing plate (3), and the included angle between adjacent connection points is 90°.

5. The monitoring device for the surrounding rock pressure of a highway tunnel according to claim 1, characterized in that: The contact surfaces between the inner wall of the clamping groove (42) and the iron fixing piece (43) are all rough surfaces.

6. The monitoring device for the surrounding rock pressure of a highway tunnel according to claim 1, wherein: The iron fixing piece (43) has a circular thin plate structure.

7. The monitoring device for the surrounding rock pressure of a highway tunnel according to claim 1, characterized in that: The connection positions of the plurality of support rods (4) and the backing plate (3) are located in the area 0-2 cm inward from the edge of the backing plate (3).

8. The monitoring device for the surrounding rock pressure of a highway tunnel according to claim 1, characterized in that: The plurality of clamping grooves (42) are equally spaced along the axial direction of the support rod (4).

9. The monitoring device for the surrounding rock pressure of a highway tunnel according to claim 1, characterized in that: The length of the support rod (4) is determined according to the reserved deformation amount in the tunnel design.

10. The monitoring device for the surrounding rock pressure of a highway tunnel according to claim 1, characterized in that: In the adjustable state of the device, the connecting plate (5) moves along the axial direction of the support rod (4).

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