A tunnel surrounding rock pressure monitoring device

Abstract

The utility model discloses a tunnel surrounding rock pressure monitoring devices belongs to the tunnel construction monitoring technical field. The device includes mounting bracket and the earth pressure cell of being located in the mounting bracket, the mounting bracket includes lower base plate, upper base plate and spacing ring, upper base plate is arranged side by side with lower base plate, and is connected with lower base plate through a plurality of fastening components, one end of spacing ring is fixedly connected with upper base plate, and is located between upper base plate and lower base plate, the earth pressure cell is located between upper base plate and lower base plate, and is located the inside of spacing ring. Through the earth pressure cell response upper base plate bears the surrounding rock pressure, and then indirectly realizes the surrounding rock pressure amount of measurement acting on the lining steel frame, solves the uneven stress problem that the earth pressure cell directly contacts surrounding rock and monitors surrounding rock pressure, makes the surrounding rock pressure more representative that is monitored.

Description

Technical Field

[0001] This utility model relates to a tunnel surrounding rock pressure monitoring device, belonging to the field of tunnel construction monitoring technology. Background Technology

[0002] During tunnel construction, when encountering adverse geological conditions, it is necessary to monitor the surrounding rock pressure in order to understand the stress state and changing trend of the surrounding rock in real time, thereby grasping the stress situation of the tunnel support structure and judging the stress stability of the tunnel support structure.

[0003] Currently, most methods involve directly contacting the earth pressure cell with the surrounding rock to monitor the rock pressure. This monitoring method can easily lead to uneven stress distribution on the earth pressure cell, resulting in a decrease in the representativeness of the rock pressure monitored by the earth pressure cell. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a tunnel surrounding rock pressure monitoring device.

[0005] This utility model is achieved through the following technical solution: A tunnel surrounding rock pressure monitoring device includes a mounting frame and an earth pressure cell disposed within the mounting frame. The mounting frame includes a lower base plate, an upper base plate, and a limiting ring. The upper base plate and the lower base plate are arranged side by side and connected to the lower base plate by multiple fastening components. One end of the limiting ring is fixedly connected to the upper base plate and is located between the upper base plate and the lower base plate. The earth pressure cell is located between the upper base plate and the lower base plate and is located inside the limiting ring.

[0006] The earth pressure cell is cylindrical and fits with a limiting ring with a clearance.

[0007] The lower base plate is fixedly mounted on the back of the lining steel frame.

[0008] The diameter of the earth pressure cell is in the range of 0.6b to 0.8b, where b is the width of the lining steel frame.

[0009] Both the upper and lower substrates are made of steel plates with a thickness of 0.8cm to 1.0cm.

[0010] The length and width of the upper substrate are the same as the length and width of the lower substrate.

[0011] The length of the upper substrate is 1.5b, where b is the width of the lining steel frame, and the width of the upper substrate is 1.5 times the outer diameter of the limiting ring.

[0012] The height of the limiting ring is 0.8 times the height of the earth pressure cell.

[0013] The beneficial effects of this utility model are as follows: the earth pressure box is placed in the mounting frame, the earth pressure box is limited laterally by the limiting ring, and the earth pressure box is limited longitudinally by the cooperation of the upper and lower base plates. The earth pressure box senses the surrounding rock pressure borne by the upper base plate, thereby indirectly realizing the measurement of the surrounding rock pressure acting on the lining steel frame. This solves the problem of uneven force distribution that occurs when the earth pressure box directly contacts the surrounding rock to monitor the surrounding rock pressure, making the monitored surrounding rock pressure more representative. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the assembly structure of the present invention and the lining steel frame; Figure 2 for Figure 1 Top view; Figure 3 This is a schematic diagram of the structure of the present invention for monitoring the surrounding rock pressure of a newly built tunnel.

[0015] In the figure: 1-mounting frame, 11-lower base plate, 12-upper base plate, 13-limiting ring, 14-fastening assembly, 2-earth pressure box, 3-lining steel frame, 4-newly built tunnel, 5-arch waist pressure measuring point, 6-arch shoulder pressure measuring point, 7-arch crown pressure measuring point. Detailed Implementation

[0016] The technical solution of this utility model is further described below, but the scope of protection is not limited to what is described.

[0017] like Figures 1 to 3 As shown, the tunnel surrounding rock pressure monitoring device of this utility model includes a mounting frame 1 and an earth pressure cell 2 disposed within the mounting frame 1. The mounting frame 1 includes a lower base plate 11, an upper base plate 12, and a limiting ring 13. The upper base plate 12 is arranged side by side with the lower base plate 11 and is connected to the lower base plate 11 by multiple fastening components 14. One end of the limiting ring 13 is fixedly connected to the upper base plate 12 and is located between the upper base plate 12 and the lower base plate 11. The earth pressure cell 2 is located between the upper base plate 12 and the lower base plate 11 and is located inside the limiting ring 13. Specifically, the fastening components 14 include bolts, nuts, spring washers, and flat washers. The upper base plate 12 can move freely along the bolt axis.

[0018] When installing the tunnel surrounding rock pressure monitoring device, the lower base plate 11 is first welded and fixed to the lining steel frame 3, ensuring that the lower base plate 11 is perpendicular to the pressure direction. Then, the mounting frame 1 is assembled, and during the assembly of the mounting frame 1, the earth pressure cell 2 is placed inside the mounting frame 1. The earth pressure cell 2 is limited laterally (radially) by the limiting ring 13, and the earth pressure cell 2 is limited longitudinally (axially) by the cooperation of the upper base plate 12 and the lower base plate 11. The earth pressure cell 2 senses the surrounding rock pressure borne by the upper base plate 12, thereby indirectly realizing the measurement of the surrounding rock pressure acting on the lining steel frame 3. This method of measuring surrounding rock pressure has the following advantages: First, it solves the problem of uneven stress distribution that occurs when the earth pressure cell 2 directly contacts the surrounding rock to monitor the surrounding rock pressure, making the monitored surrounding rock pressure more representative.

[0019] Secondly, the earth pressure monitoring mechanism is easy to install. It does not require professional personnel to provide on-site guidance, nor does it require complicated procedures such as backfilling around the earth pressure box 2. The complete set of tunnel surrounding rock pressure monitoring devices only needs to be welded and fixed to the lining steel frame 3 before the lining steel frame 3 is installed, which can truly ensure that the installation quality and installation progress are controllable.

[0020] The earth pressure box 2 is cylindrical and fits with the limiting ring 13 with a clearance. The earth pressure box 2 and the limiting ring 13 fit with a clearance, and the height of the limiting ring 13 is 0.8 times the height of the earth pressure box 2, to ensure that the earth pressure box 2 can be properly placed inside the limiting ring 13 without deflection, and can normally monitor the pressure of the surrounding rock of the tunnel lining.

[0021] The lower base plate 11 is welded and fixed to the back of the lining steel frame 3.

[0022] The diameter of the earth pressure cell 2 is in the range of 0.6b to 0.8b, where b is the width of the lining steel frame 3. For example... Figure 1 As shown, when the lining steel frame 3 is an I20a I-beam, its width b (i.e., leg width) is 10cm, then the diameter of the earth pressure box 2 can be selected within the range of 6cm to 8cm.

[0023] The range of earth pressure cell 2 should be 1.2 to 1.5 times the estimated pressure. The sensitivity and error of earth pressure cell 2 should be selected in accordance with the requirements of the relevant industry specifications. For example, in highway tunnels, the testing accuracy of earth pressure cell 2 should meet the requirement of 0.01 MPa specified in Article 18.1.7 of the "Technical Specification for Highway Tunnel Construction" (JTGT3660-2020).

[0024] Both the upper substrate 12 and the lower substrate 11 are made of steel plates with a thickness of 0.8cm to 1.0cm.

[0025] The length and width of the upper substrate 12 are the same as the length and width of the lower substrate 11.

[0026] The length of the upper substrate 12 is 1.5b, where b is the width of the lining steel frame 3, and the width of the upper substrate 12 is 1.5 times the outer diameter of the limiting ring 13.

[0027] The height of the limiting ring 13 is 0.8 times the height of the earth pressure box 2.

[0028] like Figure 3 As shown, tunnel surrounding rock pressure monitoring devices are installed at the arch waist pressure measuring point 5, arch shoulder pressure measuring point 6, and arch crown pressure measuring point 7 of the newly built tunnel 4, respectively, to monitor the surrounding rock pressure at the arch waist, arch shoulder, and arch crown of the newly built tunnel 4.

Claims

1. A tunnel surrounding rock pressure monitoring device, characterized in that: The device includes a mounting frame (1) and a soil pressure box (2) disposed within the mounting frame (1). The mounting frame (1) includes a lower base plate (11), an upper base plate (12), and a limiting ring (13). The upper base plate (12) is arranged side by side with the lower base plate (11) and is connected to the lower base plate (11) by a plurality of fastening components (14). One end of the limiting ring (13) is fixedly connected to the upper base plate (12) and is located between the upper base plate (12) and the lower base plate (11). The soil pressure box (2) is located between the upper base plate (12) and the lower base plate (11) and is located inside the limiting ring (13).

2. The tunnel surrounding rock pressure monitoring device as described in claim 1, characterized in that: The earth pressure box (2) is cylindrical and is fitted with a limiting ring (13) with a clearance.

3. The tunnel surrounding rock pressure monitoring device as described in claim 2, characterized in that: The lower base plate (11) is fixedly mounted on the back of the lining steel frame (3).

4. The tunnel surrounding rock pressure monitoring device as described in claim 3, characterized in that: The diameter of the earth pressure cell (2) is in the range of 0.6b to 0.8b, where b is the width of the lining steel frame (3).

5. The tunnel surrounding rock pressure monitoring device as described in claim 1, characterized in that: Both the upper substrate (12) and the lower substrate (11) are made of steel plates with a thickness of 0.8cm to 1.0cm.

6. The tunnel surrounding rock pressure monitoring device as described in claim 3, characterized in that: The length and width of the upper substrate (12) are the same as the length and width of the lower substrate (11).

7. The tunnel surrounding rock pressure monitoring device as described in claim 6, characterized in that: The length of the upper substrate (12) is 1.5b, where b is the width of the lining steel frame (3); The width of the upper substrate (12) is 1.5 times the outer diameter of the limiting ring (13).

8. The tunnel surrounding rock pressure monitoring device as described in claim 1, characterized in that: The height of the limiting ring (13) is 0.8 times the height of the earth pressure box (2).

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