Contact channel temperature monitoring device in tunnel freezing construction

Abstract

The utility model relates to the technical field of tunnel connection channel construction, and discloses a connection channel temperature monitoring device in tunnel freezing construction, which is based on tunnels, a connection channel is excavated between two parallel tunnels, and segments are welded and laid in corresponding segments of end ports of the connection channel of the tunnels. A prestressed support is arranged in the pipe piece for supporting, and a formwork supporting frame is erected in the connecting channel. A plurality of groups of temperature measuring drill holes are formed in the frozen wall around the contact channel in a distributed and through manner, and a weak fiber grating temperature optical cable penetrates into each group of temperature measuring drill holes. According to the contact channel temperature monitoring device in the tunnel freezing construction, the problems that in the construction process, the conditions of severe tunnel environment, sudden power failure and the like occur frequently, and at the moment, an electronic temperature sensor is difficult to transmit temperature information in real time, so that monitoring information is lost, and the construction safety is reduced are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel communication channel construction, in particular to a communication channel temperature monitoring device during tunnel freezing construction. Background Art

[0002] The excavation of connecting passages in tunnels usually adopts the freezing method. During the freezing process, it is necessary to conduct more comprehensive temperature field monitoring at different positions of the frozen wall to ensure that the conditions for freezing excavation are met and to ensure construction safety during the excavation process.

[0003] Traditional temperature detection mostly involves drilling holes of different depths at specific locations on the frozen wall and inserting electronic temperature sensors. The sensors in each hole are about 1m or 0.5m apart. This layout method is point monitoring, which cannot fully obtain the temperature field information of the frozen wall. In addition, the tunnel environment is relatively harsh during construction, and sudden power outages often occur. At this time, it is difficult for electronic temperature sensors to transmit temperature information in real time, resulting in the loss of monitoring information and reduced construction safety. Utility Model Content

[0004] In view of the deficiencies in the prior art, the present invention provides a temperature monitoring device for a communication channel during tunnel freezing construction, which solves the problems mentioned in the above background.

[0005] The utility model provides the following technical solution: a temperature monitoring device for a connecting channel during tunnel freezing construction, based on a tunnel, wherein a connecting channel is excavated between two parallel tunnels, and pipe segments are welded and laid in corresponding sections at the end openings of the connecting channel. Prestressed brackets are provided inside the pipe segments for support, and a formwork frame is erected inside the connecting channel;

[0006] A plurality of groups of temperature measuring boreholes are distributedly drilled in the frozen wall surrounding the communication channel, a weak fiber Bragg grating temperature cable is passed through each group of the temperature measuring boreholes, a passing optical cable is fused to the end of the weak fiber Bragg grating temperature cable, and a weak fiber Bragg grating demodulator is installed along the tunnel at one end of the passing optical cable away from the weak fiber Bragg grating temperature cable. The weak fiber Bragg grating demodulator is provided with a temperature reading interface.

[0007] Preferably, the grating spacing on the weak fiber Bragg grating temperature cable is 0.1 m.

[0008] Preferably, the top of the inner wall of the communication channel is supported by a thick steel plate through a formwork frame, and multiple groups of steel pipes are distributed between the formwork frame and the thick steel plate.

[0009] Preferably, a wooden template is pressed against the side of the inner wall of the communication channel, and the wooden template is arranged between the formwork frame and the inner wall of the communication channel.

[0010] Preferably, a channel port is opened on the pipe segment of the inner wall of the tunnel, and the size of the channel port corresponds to the size of the interior of the communication channel.

[0011] Preferably, the prestressed support includes a first channel steel, a second channel steel, a first mounting part, a second mounting part, a jack and a diagonal brace. The first channel steel and the second channel steel are both provided with two diagonally installed frame structures. Second mounting parts are provided at the corners on both sides of the first channel steel at the top. The first mounting part is installed in the middle of the first channel steel at the top. Jacks are installed at the ends of the first mounting part and the second mounting part. Diagonal braces are used to support the first and second mounting parts. The first mounting parts are installed on the second channel steels on both sides, and diagonal braces are provided between the second channel steel and the first mounting part installed thereon for support. Three supporting legs are provided on the first channel steel at the bottom, and the ends of the jacks and the supporting legs are provided with supports to contact the steel sheets in the tunnel.

[0012] Preferably, the formwork frame includes a crown frame and a steel arch frame, the steel arch frame is installed on the top of the crown frame, there are two crown frames, and they are separated on both sides of the inner wall of the connecting channel, a support rod is arranged between the two crown frames, an I-beam is arranged on the steel arch frame, and a support rod is arranged between the I-beam and the steel arch frame for support, and multiple groups of pipe grooves are opened on the outer edge of the steel arch frame.

[0013] Preferably, a steel section is provided at the bottom of the arch frame, and a wooden pad is sandwiched between the steel section and the arch frame.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. The temperature monitoring device for the communication channel during the freezing construction of the tunnel is designed by setting up drilling holes around the communication channel after freezing, and installing weak fiber Bragg grating temperature cables in the holes. Thanks to the advantage that a single fiber Bragg grating temperature cable can etch a grating area every 0.1m, quasi-distributed temperature monitoring can be performed on each temperature measurement borehole to obtain more complete temperature field information. Furthermore, the unique advantage of fiber optic sensing that does not require power supply can be utilized to overcome the relatively harsh construction environment on site, complete real-time monitoring of the communication channel, and improve construction safety.

[0016] 2. The temperature monitoring device for the connecting channel during the freezing construction of the tunnel sets pipe segments in the tunnel and uses prestressed supports for support. This ensures that before the temperature measurement drilling, the ends of the connecting channel in the excavation section will not collapse due to insufficient freezing, thereby ensuring that the tunnel has sufficient support capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1This is a schematic diagram of the temperature monitoring system connection of the utility model;

[0018] Figure 2 This is a schematic diagram of the segmented construction structure of the tunnel connecting channel of the utility model;

[0019] Figure 3 This is a schematic diagram of the cross-sectional structure of the communication channel of the present utility model;

[0020] Figure 4 This is a schematic diagram of the cross-sectional structure of the communication channel of the utility model;

[0021] Figure 5 This is a schematic diagram of the prestressed support structure of the utility model;

[0022] Figure 6 This is a schematic diagram of the internal support structure of the communication channel of the utility model;

[0023] Figure 7 This is a schematic diagram of the formwork support structure of the utility model.

[0024] In the figure: 1. Tunnel; 2. Communication channel; 3. Prestressed support; 31. First channel steel; 32. Second channel steel; 33. First connecting piece; 34. Second connecting piece; 35. Jack; 36. Diagonal brace; 37. Support leg; 4. Wooden formwork; 5. Thick steel plate; 6. Formwork frame; 61. Arch frame; 62. Steel arch frame; 63. I-beam; 64. Support rod; 65. Strut; 66. Wooden pad; 67. Pipe trough; 7. Temperature measurement drilling hole; 8. Low-pressure fiber Bragg grating temperature cable; 9. Passage optical cable; 10. Low-pressure fiber Bragg grating demodulator; 11. Temperature reading interface; 12. Channel port; 13. Steel pipe; 14. Steel section. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] See also Figure 1-7 A temperature monitoring device for a connecting channel during tunnel freezing construction is provided, based on a tunnel 1. A connecting channel 2 is excavated between two parallel tunnels 1. Tube segments are welded and laid in the corresponding sections of the end openings of the connecting channel 2 in the tunnel 1. Prestressed supports 3 are provided inside the segments for support. A formwork frame 6 is set inside the connecting channel 2.

[0027] A plurality of groups of temperature measuring boreholes 7 are distributedly drilled in the frozen wall around the communication channel 2. A weak fiber Bragg grating temperature cable 8 is inserted into each group of temperature measuring boreholes 7. A pass optical cable 9 is fused to the end of the weak fiber Bragg grating temperature cable 8. The pass optical cable 9 is arranged along the tunnel 1 at one end away from the weak fiber Bragg grating temperature cable 8 and is installed with a weak fiber Bragg grating demodulator 10. The weak fiber Bragg grating demodulator 10 is provided with a temperature reading interface 11. The technology of using the weak fiber Bragg grating temperature cable 8 to monitor the communication channel 2 in the freezing construction method is proposed to solve the disadvantages of traditional point temperature monitoring, thereby obtaining a more comprehensive frozen wall temperature field, ensuring that the excavation condition temperature is reached, and ensuring construction safety during the excavation process.

[0028] Among them; the grating spacing on the weak fiber Bragg grating temperature cable 8 is 0.1m, and the temperature of the frozen wall of the communication channel 2 can be detected every 0.1m, which improves the detection density and obtains more complete temperature field information.

[0029] Among them, the top of the inner wall of the connecting channel 2 is supported by a thick steel plate 5 through a formwork frame 6, and multiple groups of steel pipes 13 are distributed between the formwork frame 6 and the thick steel plate 5. The multiple groups of steel pipes 13 are used to support the thick steel plate 5, which increases the coverage area of the formwork frame 6 during support, thereby increasing the force range of the thick steel plate 5.

[0030] Among them, a wooden template 4 is pressed against the side of the inner wall of the communication channel 2, and the wooden template 4 is set between the formwork frame 6 and the inner wall of the communication channel 2. The wooden template 4 is used to assist the straight wall section in the communication channel 2 so that the straight wall section of the communication channel 2 will not collapse during excavation.

[0031] Among them, a channel port 12 is opened on the pipe segment of the inner wall of the tunnel 1, and the size of the channel port 12 corresponds to the size inside the communication channel 2. When constructing the communication channel 2, the pipe segment at the corresponding position is opened along the edge, and a weak fiber optic Bragg grating temperature cable 8 is set. This is used to compare and determine whether the installation position of the weak fiber optic Bragg grating temperature cable 8 is accurate, so as to avoid the weak fiber optic Bragg grating temperature cable 8 and the communication channel 2 from crossing and affecting the construction.

[0032] Among them, the prestressed bracket 3 includes a first channel steel 31, a second channel steel 32, a first mounting member 33, a second mounting member 34, a jack 35 and a diagonal brace 36. The first channel steel 31 and the second channel steel 32 are both provided with two diagonally installed frame structures. The second mounting members 34 are provided at the corners on both sides of the first channel steel 31 at the top. The first mounting member 33 is installed in the middle of the first channel steel 31 at the top. The ends of the first mounting member 33 and the second mounting member 34 are both installed with jacks 35. The first mounting member 33 and the second mounting member 34 are connected by a The tunnel 1 is supported by diagonal braces 36. The first connecting parts 33 are installed on the second channel steels 32 on both sides, and diagonal braces 36 are provided between the second channel steels 32 and the first connecting parts 33 installed thereon for support. Three support legs 37 are provided on the first channel steel 31 at the bottom. The ends of the jacks 35 and the support legs 37 are provided with supports to contact the pipe segments in the tunnel 1. The prestressed brackets 3 are combined with the pipe segments to support the tunnel 1, so that before the temperature measurement drilling, the ends of the connecting channel 2 in the excavation section will not cause the tunnel 1 to collapse due to insufficient freezing and drilling.

[0033] Among them; the formwork frame 6 includes a crown frame 61 and a steel arch frame 62, the steel arch frame 62 is installed on the top of the crown frame 61, the number of the crown frames 61 is two, and they are separated on both sides of the inner wall of the communication channel 2, a support rod 65 is arranged between the two crown frames 61, an I-beam 63 is arranged on the steel arch frame 62, and a support rod 64 is arranged between the I-beam 63 and the steel arch frame 62 for support. A plurality of groups of pipe grooves 67 are provided on the outer edge of the steel arch frame 62. When the communication channel 2 is constructed, the temperature monitoring capability of the weak fiber grating temperature cable 8 is used to determine the freezing condition of the tunnel 1. Combined with the load-bearing capacity of the formwork frame 6, the safety of the communication channel 2 can be quickly judged.

[0034] wherein; the bottom of the frame 61 is provided with a steel section 14, and a wooden pad 66 is sandwiched between the steel section 14 and the frame 61 of the spherical frame. The steel section 14 is provided on the concrete surface of the poured bottom plate, and then the steel section 14 is used to support the bottom end of the spherical frame 61, thereby increasing the contact area of the bottom of the spherical frame 61 to avoid depression of the concrete surface.

[0035] Temperature measurement principle of weak fiber Bragg grating temperature cable 8:

[0036] Since the wavelength of weak fiber Bragg grating is affected by temperature and strain, but in the temperature optical cable, the grating area is in a relaxed state, so the influence of strain is eliminated. The following formula can be obtained:

[0037] Δλ B =K t ΔT

[0038] Where Δλ B is the wavelength variation (read from the weak fiber Bragg grating demodulator 10), K tis the temperature coefficient of the weak fiber Bragg grating (provided by the manufacturer and is a constant), and ΔT is the temperature change value.

[0039] Assuming the ambient temperature is T0, put it into the hole to be measured, then the temperature of a certain point in the hole to be measured is

[0040] The temperature inside the borehole can therefore be determined.

[0041] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A temperature monitoring device for a communication channel during tunnel freezing construction, based on a tunnel (1), characterized in that: A connecting channel (2) is excavated between the two parallel tunnels (1), and pipe segments are welded and laid in the corresponding sections of the end openings of the connecting channel (2) of the tunnel (1), and prestressed supports (3) are provided inside the pipe segments for support, and a formwork frame (6) is set up inside the connecting channel (2); A plurality of groups of temperature measuring boreholes (7) are distributedly drilled in the frozen wall surrounding the communication channel (2), a weak fiber Bragg grating temperature optical cable (8) is inserted into each group of the temperature measuring boreholes (7), a passing optical cable (9) is fused to the end of the weak fiber Bragg grating temperature optical cable (8), and a weak fiber Bragg grating demodulator (10) is installed on the end of the passing optical cable (9) away from the weak fiber Bragg grating temperature optical cable (8) along the tunnel (1), and the weak fiber Bragg grating demodulator (10) is provided with a temperature reading interface (11).

2. A communication channel temperature monitoring device during tunnel freezing construction according to claim 1, characterized in that: The grating spacing on the weak fiber Bragg grating temperature optical cable (8) is 0.1 m.

3. The device for monitoring the temperature of a communication channel during tunnel freezing construction according to claim 1, characterized in that: The top of the inner wall of the communication channel (2) is supported by a thick steel plate (5) through a formwork frame (6), and multiple groups of steel pipes (13) are distributed between the formwork frame (6) and the thick steel plate (5).

4. The device for monitoring the temperature of a communication channel during tunnel freezing construction according to claim 1, characterized in that: A wooden template (4) is pressed against the side surface of the inner wall of the communication channel (2), and the wooden template (4) is arranged between the formwork frame (6) and the inner wall of the communication channel (2).

5. The device for monitoring the temperature of a communication channel during tunnel freezing construction according to claim 1, characterized in that: A channel port (12) is provided on the pipe segment of the inner wall of the tunnel (1), and the size of the channel port (12) corresponds to the size of the interior of the communication channel (2).

6. The device for monitoring the temperature of a communication channel during tunnel freezing construction according to claim 1, characterized in that: The prestressed support (3) comprises a first channel steel (31), a second channel steel (32), a first connecting piece (33), a second connecting piece (34), a jack (35) and a diagonal brace (36). The first channel steel (31) and the second channel steel (32) are both provided with two diagonally mounted members to form a frame structure. The second connecting pieces (34) are both provided at the corners on both sides of the first channel steel (31) at the top. The first connecting piece (33) is installed in the middle of the first channel steel (31) at the top. The ends of the first connecting piece (33) and the second connecting piece (34) are connected to the first channel steel (31). The first and second connecting parts (33 and 34) are supported by a slanting brace (36). The first connecting parts (33) are installed on the second channel steels (32) on both sides, and a slanting brace (36) is provided between the second channel steels (32) and the first connecting parts (33) installed thereon for support. The first channel steel (31) at the bottom is provided with three supporting legs (37). The ends of the jacks (35) and the supporting legs (37) are provided with supports to contact the steel sheets in the tunnel (1).

7. The device for monitoring the temperature of a communication channel during tunnel freezing construction according to claim 1, characterized in that: The formwork frame (6) includes a frame (61) and a steel arch frame (62). The steel arch frame (62) is installed on the top of the frame (61). There are two frame frames (61) and they are located on both sides of the inner wall of the communication channel (2). A support rod (65) is provided between the two frame frames (61). An I-beam (63) is provided on the steel arch frame (62). A support rod (64) is provided between the I-beam (63) and the steel arch frame (62) for support. A plurality of pipe grooves (67) are provided on the outer edge of the steel arch frame (62).

8. The device for monitoring the temperature of a communication channel during tunnel freezing construction according to claim 7, characterized in that: A section steel (14) is provided at the bottom of the arch frame (61), and a wooden pad (66) is sandwiched between the section steel (14) and the arch frame (61).

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