Safety monitoring device and method for construction of box culvert under railway

Abstract

The present application relates to the technical field of railway box culvert, and more particularly to a safety monitoring device and method for an existing box culvert during construction of a box culvert underpassing a railway, which comprises a shell, two support rods fixedly connected to the upper surface of the shell, a top plate fixedly connected to the side surface of the support rod, a probe arranged above the shell, a moving mechanism arranged on the lower surface of the shell for movement, an elongation mechanism arranged on the side surface of the shell for elongation, a measuring mechanism arranged on the upper surface of the top plate for rotation of the probe, and a power mechanism arranged on the upper surface of the shell for power supply. The moving mechanism is arranged, which is conducive to moving the shell inside the box culvert when needed. An electric signal is generated by a remote controller to start a motor inside the shell. The motor drives the rotation of a rotating shaft, and the rotating shaft drives the rotation of a moving wheel to realize the movement of the shell inside the box culvert and the comprehensive monitoring of the inside of the box culvert.

Description

Technical Field

[0001] This invention relates to the field of railway box culvert technology, and more specifically to a safety monitoring device and method for existing box culverts during the construction of box culverts under railways. Background Technology

[0002] A box culvert refers to a culvert whose tunnel body is constructed using reinforced concrete box-shaped pipe sections. A box culvert consists of one or more square or rectangular cross-sections, generally made of reinforced concrete or masonry. During the construction of railway box culverts, to ensure the safe use of the railway, safety monitoring of existing box culverts is necessary. This monitoring requires a safety monitoring device for existing box culverts under railway construction. This device is primarily composed of an outer shell assembly, monitoring components, connection assemblies, and transmission components. It offers advantages such as ease of use, accurate monitoring results, and applicability to various railway box culvert types.

[0003] Common safety monitoring devices used during the construction of box culverts under railways generally have the following defects:

[0004] Firstly, during the construction of box culverts under railways, the safety monitoring devices for existing box culverts require operators to use connecting rods to send the monitoring devices into the box culvert for testing. However, since box culverts are generally long, it is not possible to send the monitoring devices into the box culvert, resulting in incomplete monitoring of the inside of the box culvert.

[0005] Secondly, when the safety monitoring device for the existing box culvert is used to test the width of the working side wall inside the box culvert during the construction of the common box culvert under the railway, infrared measurement is used. However, since the bottom of the box culvert may be uneven, the measurement results will be biased, which is not conducive to monitoring the width inside the box culvert.

[0006] Thirdly, when constructing box culverts under railways, the safety monitoring devices for existing box culverts use probes to record and transmit the internal conditions of the box culverts. However, because the probes are fixed in orientation, they record directly in a single direction, resulting in incomplete recording of the internal conditions of the box culverts and hindering comprehensive monitoring of the internal conditions.

[0007] In summary, common safety monitoring devices used during the construction of box culverts under railways generally have shortcomings in their application, such as incomplete monitoring of the box culvert's interior, incomplete monitoring of the box culvert's width, and incomplete recording of the box culvert's internal condition. Summary of the Invention

[0008] In order to overcome the above-mentioned defects of the prior art, the present invention provides a safety monitoring device and method for existing box culverts during the construction of box culverts under railways, so as to solve the problems existing in the background art.

[0009] The present invention provides the following technical solution: a safety monitoring device and method for existing box culverts during the construction of box culverts under railways, comprising an outer shell, two support rods fixedly connected to the upper surface of the outer shell, a top plate fixedly connected to the side of the support rods, a probe disposed on the upper surface of the outer shell, a moving mechanism for moving the probe disposed on the lower surface of the outer shell, an extension mechanism for extending the probe disposed on the side of the outer shell, a measuring mechanism for rotating the probe disposed on the upper surface of the top plate, and a power mechanism for providing power disposed on the upper surface of the outer shell;

[0010] The moving mechanism includes four moving slots formed on the upper surface of the housing. Each moving slot has a rotating shaft rotatably connected to its side wall, and a moving wheel is fitted on the outer wall of the rotating shaft.

[0011] Furthermore, the probe is located above the camera, directly above the top panel.

[0012] Furthermore, the four movable slots are respectively located at the four corners of the lower surface of the housing, the lower ends of the movable wheels extend from inside the movable slots and contact the ground, and the rotation of the rotating shaft can be driven by a motor controlled by an electrical signal.

[0013] Furthermore, the elongation mechanism includes a telescopic groove formed on the side of the outer shell, two movable plates are slidably connected inside the telescopic groove, each movable plate has a threaded hole through its side, a lifting plate is slidably connected to the side of the support rod, a threaded rod is rotatably connected inside the telescopic groove, the two ends of the threaded rod are respectively located inside the threaded hole, a first bevel gear is sleeved on the outer wall of the threaded rod, a transmission rod is rotatably connected to the upper surface of the outer shell, the upper end of the transmission rod is sleeved with the first gear and passes through the lifting plate and is fixedly connected with a limiting rod, and the lower end of the transmission rod extends into the telescopic groove and is sleeved with a second bevel gear.

[0014] Furthermore, an electric telescopic rod is installed on the upper surface of the housing, the telescopic end of the electric telescopic rod is fixedly connected to the lower surface of the lifting plate, the first bevel gear meshes with the second bevel gear, the telescopic groove penetrates the side wall of the housing, and the outer wall of the threaded rod is double-threaded and threadedly connected to two threaded holes.

[0015] Furthermore, the measuring mechanism includes a rotating rod rotatably connected to the surface of the top plate, a connecting rod fixedly connected to the side of the rotating rod, the other end of the connecting rod being fixedly connected to the probe, and the lower end of the rotating rod penetrating the top plate and having a limiting groove.

[0016] Furthermore, the limiting groove and the limiting rod are adapted to each other and both have rectangular cross-sections.

[0017] Furthermore, the power mechanism includes two support blocks fixedly connected to the upper surface of the housing. A support platform is fixedly connected to the side of the support block, and a motor is installed on the side of the support platform. A power rod is rotatably connected to the upper surface of the housing. The upper end of the power rod is fixedly connected to the end of the output shaft of the motor, and a second gear is sleeved on the outer wall of the power rod.

[0018] Furthermore, the first gear meshes with the second gear, and the thickness of the first gear is greater than the thickness of the second gear.

[0019] Furthermore, the following steps are included:

[0020] S1: First, place the outer shell directly inside the box culvert that needs to be monitored;

[0021] S2: Start the motor. The motor drives the power rod and the second gear to rotate. The second gear drives the first gear and the transmission rod to rotate. Start the electric telescopic rod. The electric telescopic rod drives the lifting plate and the transmission rod to move down, so that the first bevel gear meshes with the second bevel gear. The transmission rod drives the second bevel gear to rotate. The second bevel gear drives the first bevel gear and the threaded rod to rotate. Since the outer wall of the threaded rod has a double-threaded design and is threaded to two threaded holes, the rotation of the threaded rod drives the two moving plates to move out of the telescopic groove and contact the inner wall of the box culvert, so as to achieve the purpose of measuring the width of the inner wall of the box culvert.

[0022] S3: Start the electric telescopic rod. The electric telescopic rod pushes the lifting plate and the transmission rod upward, so that the first bevel gear and the second bevel gear separate. The limiting rod enters the limiting groove. The transmission rod rotates and drives the rotating rod to rotate through the limiting rod and the limiting groove. The rotating rod rotates and drives the probe to rotate through the connecting rod, so as to realize the imaging and comparison of the internal state of the box culvert.

[0023] S4: An electrical signal is generated via remote control to start the motor inside the outer shell. The motor drives the rotating shaft to rotate, which in turn drives the moving wheels to rotate, enabling the outer shell to move inside the box culvert and achieve comprehensive monitoring of the inside of the box culvert.

[0024] The technical effects and advantages of this invention are as follows:

[0025] 1. By setting up a moving mechanism, this invention facilitates the movement of the outer shell inside the box culvert when it is necessary to move the outer shell. An electrical signal is generated by a remote control to start the motor inside the outer shell. The motor drives the rotating shaft to rotate, and the rotating shaft drives the moving wheels to rotate, thereby enabling the outer shell to move inside the box culvert. This allows for comprehensive monitoring of the box culvert's interior without the need for manual insertion of the outer shell into the box culvert using a connecting rod, making it simple and convenient.

[0026] 2. This invention, by incorporating an extension mechanism, facilitates the measurement of the culvert's interior when necessary. The motor is activated, driving the power rod and second gear to rotate. The second gear, in turn, drives the first gear and transmission rod to rotate. This activates the electric telescopic rod, which in turn moves the lifting plate and transmission rod downwards, causing the first and second bevel gears to mesh. The transmission rod then drives the second bevel gear to rotate, which in turn drives the first bevel gear and threaded rod to rotate. Since the threaded rod has a double-threaded outer wall and is threaded to two threaded holes, its rotation causes two moving plates to move out of the telescopic groove and contact the inner wall of the culvert, achieving the purpose of measuring the width of the culvert's inner wall and making the measurement of the culvert's interior more accurate.

[0027] 3. This invention, by incorporating a measuring mechanism, facilitates monitoring of the internal condition of the box culvert. Activating the electric telescopic rod pushes the lifting plate and transmission rod upwards, causing the first and second bevel gears to separate. The limiting rod enters the limiting groove, and the rotation of the transmission rod, through the limiting rod and limiting groove, drives the rotating rod to rotate. The rotation of the rotating rod, through the connecting rod, drives the probe to rotate, enabling the imaging and comparison of the internal condition of the box culvert. This allows for comprehensive detection of the box culvert's interior, resulting in more accurate monitoring results.

[0028] 4. By incorporating a power mechanism, this invention facilitates the control of the extension mechanism and measuring mechanism by using an electric telescopic rod to control the up-and-down movement of the transmission rod. This allows for the control of multiple mechanisms using a single power source, thus saving on the use of power sources. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0030] Figure 2 This is a schematic diagram of the moving mechanism structure of the present invention.

[0031] Figure 3 for Figure 2 An exploded view of the moving slot structure in the diagram.

[0032] Figure 4 This is a schematic diagram of the elongation mechanism of the present invention.

[0033] Figure 5 for Figure 4 An exploded view of the expansion joint structure.

[0034] Figure 6 This is a schematic diagram of the measuring mechanism structure of the present invention.

[0035] Figure 7 for Figure 2 A schematic diagram of the limiting groove structure.

[0036] Figure 8 This is a schematic diagram of the power mechanism structure of the present invention.

[0037] Figure 9 This is a flowchart illustrating the operation of the present invention.

[0038] The attached figures are labeled as follows: 1. Outer shell; 2. Support rod; 3. Top plate; 4. Probe; 5. Moving mechanism; 501. Moving groove; 502. Moving wheel; 503. Rotating shaft; 6. Extension mechanism; 601. Moving plate; 602. Threaded hole; 603. Lifting plate; 604. Telescopic groove; 605. Threaded rod; 606. First bevel gear; 607. Transmission rod; 608. Second bevel gear; 609. First gear; 610. Limiting rod; 7. Measuring mechanism; 701. Rotating rod; 702. Connecting rod; 703. Limiting groove; 8. Power mechanism; 801. Support block; 802. Support platform; 803. Motor; 804. Power rod; 805. Second gear. Detailed Implementation

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The safety monitoring device and method for existing box culverts during the construction of underpass railway box culverts involved in the present invention are not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1

[0041] Reference Figure 1-9This invention provides a safety monitoring device and method for existing box culverts during the construction of box culverts under railways. The device includes a housing 1, with two support rods 2 fixedly connected to the upper surface of the housing 1. A top plate 3 is fixedly connected to the side of the support rods 2. A probe 4 is installed above the housing 1. A moving mechanism 5 is provided on the lower surface of the housing 1. An extension mechanism 6 is provided on the side of the housing 1. A measuring mechanism 7 for rotating the probe 4 is provided on the upper surface of the top plate 3. A power mechanism 8 for providing power is provided on the upper surface of the housing 1. By providing the moving mechanism 5, the extension mechanism 6, the measuring mechanism 7, and the power mechanism 8, the housing 1 can move inside the box culvert, the width inside the box culvert can be measured, and comprehensive monitoring of the inside of the box culvert can be performed, saving the use of a power source.

[0042] The moving mechanism 5 includes four moving slots 501 formed on the upper surface of the outer shell 1. A rotating shaft 503 is rotatably connected to the side wall of each moving slot 501. A moving wheel 502 is sleeved on the outer wall of the rotating shaft 503. The moving mechanism 5 is convenient for moving the outer shell 1 inside the box culvert when it is necessary. An electrical signal is generated by the remote control to start the motor inside the outer shell 1. The motor drives the rotating shaft 503 to rotate, and the rotating shaft 503 drives the moving wheel 502 to rotate, so as to move the outer shell 1 inside the box culvert. This enables comprehensive monitoring of the inside of the box culvert without the need for manual delivery of the outer shell 1 into the box culvert for monitoring, which is simple and convenient.

[0043] Reference Figure 1 The probe 4 is located above the camera and directly above the top plate 3. The probe 4 can record the internal state of the box culvert and transmit it to the surveyors.

[0044] Reference Figure 2 and Figure 3 Four movable slots 501 are respectively located at the four corners of the lower surface of the outer casing 1. The lower ends of the movable wheels 502 extend from the inside of the movable slots 501 and contact the ground. The rotation of the rotating shaft 503 can be driven by the motor controlled by an electrical signal. The movable mechanism 5 can be operated by sending an electrical signal through a remote control.

[0045] Reference Figure 4The extension mechanism 6 includes a telescopic groove 604 formed on the side of the outer casing 1. Two movable plates 601 are slidably connected inside the telescopic groove 604. Each movable plate 601 has a threaded hole 602 penetrating its side. A lifting plate 603 is slidably connected to the side of the support rod 2. A threaded rod 605 is rotatably connected inside the telescopic groove 604. Both ends of the threaded rod 605 are located inside the threaded holes 602. A first bevel gear 606 is sleeved on the outer wall of the threaded rod 605. A transmission rod 607 is rotatably connected to the upper surface of the outer casing 1. A first gear 609 is sleeved on the upper end of the transmission rod 607, which penetrates the lifting plate 603 and is fixedly connected to a limiting rod 610. The lower end of the transmission rod 607 extends into the telescopic groove 604 and is sleeved with a second bevel gear 608. The extension mechanism 6 facilitates adjustments when the casing needs to be adjusted. When measuring inside the culvert, the motor 803 is started. The motor 803 drives the power rod 804 and the second gear 805 to rotate. The second gear 805 drives the first gear 609 and the transmission rod 607 to rotate. The electric telescopic rod is started. The electric telescopic rod drives the lifting plate 603 and the transmission rod 607 to move down, so that the first bevel gear 606 meshes with the second bevel gear 608. The transmission rod 607 drives the second bevel gear 608 to rotate. The second bevel gear 608 drives the first bevel gear 606 and the threaded rod 605 to rotate. Since the outer wall of the threaded rod 605 has a double-threaded design and is threaded to two threaded holes 602, the rotation of the threaded rod 605 drives the two moving plates 601 to move out of the telescopic groove 604 and contact the inner wall of the culvert, so as to achieve the purpose of measuring the width of the inner wall of the culvert, making the measurement of the inside of the culvert more accurate.

[0046] Reference Figure 5 An electric telescopic rod is installed on the upper surface of the outer shell 1. The telescopic end of the electric telescopic rod is fixedly connected to the lower surface of the lifting plate 603. The first bevel gear 606 meshes with the second bevel gear 608. The telescopic groove 604 penetrates the side wall of the outer shell 1. The outer wall of the threaded rod 605 is double-threaded and threadedly connected to two threaded holes 602. When the threaded rod 605 rotates, it will drive the two moving plates 601 to move out from inside the telescopic groove 604 and contact the inner wall of the box culvert.

[0047] Reference Figure 6The measuring mechanism 7 includes a rotating rod 701 rotatably connected to the upper surface of the top plate 3. A connecting rod 702 is fixedly connected to the side of the rotating rod 701. The other end of the connecting rod 702 is fixedly connected to the probe 4. The lower end of the rotating rod 701 passes through the top plate 3 and has a limiting groove 703. The measuring mechanism 7 is provided so that when it is necessary to monitor the internal condition of the box culvert, the electric telescopic rod can be activated. The electric telescopic rod pushes the lifting plate 603 and the transmission rod 607 upward, causing the first bevel gear 606 to separate from the second bevel gear 608. The limiting rod 610 enters the limiting groove 703. The rotation of the transmission rod 607 drives the rotating rod 701 to rotate through the limiting rod 610 and the limiting groove 703. The rotation of the rotating rod 701 drives the probe 4 to rotate through the connecting rod 702, so as to realize the imaging and comparison of the internal condition of the box culvert. This allows for comprehensive detection of the internal condition of the box culvert, and the monitoring results are more accurate.

[0048] Reference Figure 7 The limiting groove 703 is adapted to the limiting rod 610 and both have rectangular cross sections, so that the transmission rod 607 rotates through the limiting rod 610 and the limiting groove 703 to drive the rotating rod 701 to rotate.

[0049] Reference Figure 8 The power mechanism 8 includes two support blocks 801 fixedly connected to the upper surface of the outer casing 1. A support platform 802 is fixedly connected to the side of the support block 801. A motor 803 is installed on the side of the support platform 802. A power rod 804 is rotatably connected to the upper surface of the outer casing 1. The upper end of the power rod 804 is fixedly connected to the end of the output shaft of the motor 803. A second gear 805 is sleeved on the outer wall of the power rod 804. The power mechanism 8 is provided to facilitate the control of the up and down movement of the transmission rod 607 through the electric telescopic rod, thereby realizing the control of the operation of the extension mechanism 6 and the measuring mechanism 7. Using one power source to control the operation of multiple mechanisms saves the use of power sources.

[0050] Reference Figure 8 The first gear 609 meshes with the second gear 805. The thickness of the first gear 609 is greater than the thickness of the second gear 805. When the transmission rod 607 drives the first gear 609 to move up and down, the second gear 805 always meshes with the first gear 609.

[0051] Reference Figure 9 This includes the following steps:

[0052] S1: First, place the outer casing 1 directly inside the box culvert that needs to be monitored;

[0053] S2: Start motor 803. Motor 803 drives power rod 804 and second gear 805 to rotate. Second gear 805 drives first gear 609 and transmission rod 607 to rotate. Start electric telescopic rod. Electric telescopic rod drives lifting plate 603 and transmission rod 607 to move down, so that first bevel gear 606 meshes with second bevel gear 608. Transmission rod 607 drives second bevel gear 608 to rotate. Second bevel gear 608 drives first bevel gear 606 and threaded rod 605 to rotate. Since the outer wall of threaded rod 605 has double-threaded and is threaded to two threaded holes 602, the rotation of threaded rod 605 drives two moving plates 601 to move out from inside telescopic groove 604 and contact the inner wall of box culvert, so as to achieve the purpose of measuring the width of the inner wall of box culvert.

[0054] S3: Start the electric telescopic rod. The electric telescopic rod pushes the lifting plate 603 and the transmission rod 607 upward, causing the first bevel gear 606 to separate from the second bevel gear 608. The limiting rod 610 enters the limiting groove 703. The rotation of the transmission rod 607 drives the rotating rod 701 to rotate through the limiting rod 610 and the limiting groove 703. The rotation of the rotating rod 701 drives the probe 4 to rotate through the connecting rod 702, so as to realize the imaging and comparison of the internal state of the box culvert.

[0055] S4: An electrical signal is generated by the remote control to start the motor inside the outer shell 1. The motor drives the rotating shaft 503 to rotate, and the rotating shaft 503 drives the moving wheel 502 to rotate, so that the outer shell 1 can move inside the box culvert and realize comprehensive monitoring of the inside of the box culvert. Through the above steps, the outer shell 1 can realize comprehensive monitoring of the internal status of the box culvert.

[0056] The working principle of this invention is as follows: When it is necessary to move the outer shell 1 inside the box culvert, an electrical signal is generated by the remote control to start the motor inside the outer shell 1. The motor drives the rotating shaft 503 to rotate, and the rotating shaft 503 drives the moving wheel 502 to rotate, so as to move the outer shell 1 inside the box culvert and realize comprehensive monitoring of the inside of the box culvert. There is no need to manually send the outer shell 1 into the box culvert for monitoring using a conveyor rod, which is simple and convenient.

[0057] When it is necessary to measure the inside of the box culvert, the motor 803 is started. The motor 803 drives the power rod 804 and the second gear 805 to rotate. The second gear 805 drives the first gear 609 and the transmission rod 607 to rotate. The electric telescopic rod is started. The electric telescopic rod drives the lifting plate 603 and the transmission rod 607 to move down, so that the first bevel gear 606 and the second bevel gear 608 mesh. The transmission rod 607 drives the second bevel gear 608 to rotate. The second bevel gear 608 drives the first bevel gear 606 and the threaded rod 605 to rotate. Since the outer wall of the threaded rod 605 has a double-threaded design and is threaded to two threaded holes 602, the rotation of the threaded rod 605 drives the two moving plates 601 to move out of the telescopic groove 604 and contact the inner wall of the box culvert, so as to achieve the purpose of measuring the width of the inner wall of the box culvert, making the measurement of the inside of the box culvert more accurate.

[0058] When monitoring the internal condition of the box culvert is required, the electric telescopic rod is activated. The electric telescopic rod pushes the lifting plate 603 and the transmission rod 607 upward, causing the first bevel gear 606 to separate from the second bevel gear 608. The limiting rod 610 enters the limiting groove 703. The rotation of the transmission rod 607 drives the rotating rod 701 to rotate through the limiting rod 610 and the limiting groove 703. The rotation of the rotating rod 701 drives the probe 4 to rotate through the connecting rod 702, realizing the imaging and comparison of the internal condition of the box culvert. This allows for comprehensive detection of the internal condition of the box culvert, and the monitoring results are more accurate.

Claims

1. A safety monitoring device for existing box culverts during the construction of box culverts under railways, comprising a housing (1), characterized in that: Two support rods (2) are fixedly connected to the upper surface of the outer shell (1). A top plate (3) is fixedly connected to the side of the support rods (2). A probe (4) is provided above the outer shell (1). The probe (4) is a camera. The probe (4) is located directly above the top plate (3). A moving mechanism (5) for moving is provided on the lower surface of the outer shell (1). An extension mechanism (6) for extending is provided on the side of the outer shell (1). A measuring mechanism (7) for rotating the probe (4) is provided on the upper surface of the top plate (3). A power mechanism (8) for providing power is provided on the upper surface of the outer shell (1). The moving mechanism (5) includes four moving slots (501) formed on the lower surface of the outer shell (1). Each moving slot (501) has a rotating shaft (503) rotatably connected to its side wall. A moving wheel (502) is sleeved on the outer wall of the rotating shaft (503). The extension mechanism (6) includes a telescopic groove (604) opened on the side of the outer shell (1). Two movable plates (601) are slidably connected inside the telescopic groove (604). Each movable plate (601) has a threaded hole (602) through its side. A lifting plate (603) is slidably connected to the side of the support rod (2). A threaded rod (605) is rotatably connected inside the telescopic groove (604). The two ends of the threaded rod (605) are respectively located inside the threaded hole (602). A first bevel gear (606) is sleeved on the outer wall of the threaded rod (605). A transmission rod (607) is rotatably connected to the upper surface of the outer shell (1). A first gear (609) is sleeved on the upper end of the transmission rod (607) and passes through the lifting plate (603) and is fixedly connected to a limiting rod (610). The lower end of the transmission rod (607) extends into the telescopic groove (604) and is sleeved with a second bevel gear (608). An electric telescopic rod is installed on the upper surface of the outer shell (1). The telescopic end of the electric telescopic rod is fixedly connected to the lower surface of the lifting plate (603). The first bevel gear (606) meshes with the second bevel gear (608). The telescopic groove (604) penetrates the side wall of the outer shell (1). The outer wall of the threaded rod (605) is double-threaded and threadedly connected to two threaded holes (602). The measuring mechanism (7) includes a rotating rod (701) rotatably connected to the upper surface of the top plate (3). A connecting rod (702) is fixedly connected to the side of the rotating rod (701). The other end of the connecting rod (702) is fixedly connected to the probe (4). The lower end of the rotating rod (701) passes through the top plate (3) and is provided with a limiting groove (703). The limiting groove (703) is adapted to the limiting rod (610) and both have rectangular cross sections. The power mechanism (8) includes two support blocks (801) fixedly connected to the upper surface of the outer shell (1). A support platform (802) is fixedly connected to the side of the support block (801). A motor (803) is installed on the side of the support platform (802). A power rod (804) is rotatably connected to the upper surface of the outer shell (1). The upper end of the power rod (804) is fixedly connected to the end of the output shaft of the motor (803). A second gear (805) is sleeved on the outer wall of the power rod (804). The first gear (609) meshes with the second gear (805). The thickness of the first gear (609) is greater than the thickness of the second gear (805).

2. The safety monitoring device for existing box culverts during the construction of box culverts under railways as described in claim 1, characterized in that: The four movable slots (501) are respectively located at the four corners of the lower surface of the outer shell (1). The lower end of the movable wheel (502) extends out from the inside of the movable slot (501) and contacts the ground. The rotation of the rotating shaft (503) can be driven by the motor controlled by the electrical signal.

3. The monitoring method for the safety monitoring device of the existing box culvert during the construction of the box culvert under the railway as described in any one of claims 1-2, characterized in that: Includes the following steps: S1: First, place the outer shell (1) directly inside the box culvert that needs to be monitored; S2: Start the motor (803). The motor (803) drives the power rod (804) and the second gear (805) to rotate. The second gear (805) drives the first gear (609) and the transmission rod (607) to rotate. Start the electric telescopic rod. The electric telescopic rod drives the lifting plate (603) and the transmission rod (607) to move down, so that the first bevel gear (606) meshes with the second bevel gear (608). The transmission rod (607) drives the second bevel gear (608) to rotate. The second bevel gear (608) drives the first bevel gear (606) and the threaded rod (605) to rotate. Since the outer wall of the threaded rod (605) is double-threaded and threadedly connected to the two threaded holes (602), the rotation of the threaded rod (605) drives the two moving plates (601) to move out from the inside of the telescopic groove (604) and contact the inner wall of the box culvert, so as to achieve the purpose of measuring the width of the inner wall of the box culvert. S3: Start the electric telescopic rod. The electric telescopic rod pushes the lifting plate (603) and the transmission rod (607) to move upward, so that the first bevel gear (606) and the second bevel gear (608) separate. The limiting rod (610) enters the limiting groove (703). The transmission rod (607) rotates and drives the rotating rod (701) to rotate through the limiting rod (610) and the limiting groove (703). The rotating rod (701) rotates and drives the probe (4) to rotate through the connecting rod (702), so as to realize the imaging and comparison of the internal state of the box culvert. S4: The remote control generates an electrical signal to start the motor inside the outer shell (1). The motor drives the rotating shaft (503) to rotate, and the rotating shaft (503) drives the moving wheel (502) to rotate, so that the outer shell (1) can move inside the box culvert and achieve comprehensive monitoring of the inside of the box culvert.

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