Bridge displacement detection device and method for bridge construction

Abstract

The invention provides a bridge displacement detection device and method for bridge construction, and belongs to the technical field of bridge displacement detection. According to the bridge construction bridge displacement detection device and method, a bridge body and two bridge pier bodies are included, a displacement detection mechanism is arranged between the two bridge pier bodies, the displacement detection mechanism comprises a sliding rail and a rectangular frame, the sliding rail is arranged below the bridge body, and hoops are fixedly arranged at the two ends of the sliding rail. By arranging the displacement detection mechanism, a recorded value is a transverse line under the condition that the bridge body does not perform displacement deformation, and the recorded value is synchronously changed under the condition that the bridge body has displacement deformation, so that the displacement condition of the bridge body is recorded; compared with the prior art, the method has the advantages that vehicles do not need to be forbidden to pass when bridge displacement detection is carried out, and the convenience degree is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bridge displacement detection, in particular to a bridge displacement detection device for bridge construction and a method thereof. BACKGROUND

[0002] In the bridge construction and operation period health monitoring, the detection of the vertical displacement of the beam body is crucial, which is a key indicator for evaluating the structural stiffness, bearing capacity and safety state. Although the existing simple mechanical type dial gauge contact measurement is stable and reliable, it can only perform single-point static measurement and cannot realize continuous scanning of the bridge bottom contour, and is easily disturbed by the bridge vibration caused by vehicle passing, resulting in data distortion.

[0003] In the prior art, there are also some automatic detection devices that attempt to combine mechanical and electronic components, but the core sensing part still relies on electronic sensors, and the problems of long-term stability, environmental tolerance and poor electromagnetic interference resistance have not been fundamentally solved. In addition, it is difficult to accurately capture the slow and trend displacement deformation of the structure under the adverse working conditions of vehicle passing, and it is very easy to be disturbed by vibration noise. SUMMARY

[0004] In order to make up for the above shortcomings, the present application provides a bridge displacement detection device for bridge construction and a method thereof, which overcomes the above technical problems or at least partially solves the above problems.

[0005] The present application is implemented as follows:

[0006] The present application provides a bridge displacement detection device for bridge construction and a method thereof, which includes a bridge body and two pier bodies, a displacement detection mechanism is arranged between the two pier bodies, the displacement detection mechanism includes,

[0007] A slide rail is arranged below the bridge body, two ends of the slide rail are fixedly provided with clamps, the two clamps are fixedly arranged on the two pier bodies respectively, and a sliding seat is arranged on the surface of the slide rail;

[0008] A rectangular frame is fixedly arranged on the top of the sliding seat, a slide rod is slidingly arranged on each vertical end of the rectangular frame, a contact head is arranged on the top of the slide rod, the top of the contact head abuts against the bottom of the bridge body, a slide is integrally formed on the central axis of the rectangular frame, a sliding block is slidingly arranged on the slide, and a lever is hinged to the sliding block.

[0009] In a preferred scheme, a reset plate is fixedly arranged on the surface of the slide rod, a first spring is arranged between the reset plate and the rectangular frame, and a second spring is arranged between the sliding block and the rectangular frame.

[0010] In a preferred scheme, a straight slot is fixed on the slide bar, and rigid short arms are fixed on both ends of the lever, and slide shafts are fixed on the rigid short arms, and the two slide shafts are respectively arranged in the straight slot.

[0011] In a preferred scheme, an articulated rod is articulated in the interior of the slide block, one end of the articulated rod is fixedly connected with the lever, the other end of the articulated rod is coaxially fixed with a first bevel gear, a support frame is fixed on the rear side of the slide block, a spline sleeve is rotatably arranged on the support frame, a second bevel gear is coaxially fixed on the surface of the spline sleeve, and the first bevel gear and the second bevel gear are engaged.

[0012] In a preferred scheme, a support seat is fixed on the rear side of the rectangular frame, a spline shaft is rotatably arranged on the support seat, and the spline sleeve is slidably sleeved on the surface of the spline shaft.

[0013] In a preferred scheme, a screw rod is coaxially fixed on the bottom of the spline shaft, a lifting block is slidably arranged on the slide rail, a lifting frame is fixed on the rear side of the lifting block, the lifting frame is threadedly sleeved on the surface of the screw rod, and a recording pen is arranged on the rear side of the lifting frame.

[0014] In a preferred scheme, two support tables are fixed on the top of the slide base, a winding drum is rotatably arranged on the support table, two pressing rollers are arranged on the top of the slide base, and the two pressing rollers are respectively located on the two sides of the recording pen.

[0015] In a preferred scheme, a winding and unwinding mechanism is arranged on the slide base, the winding and unwinding mechanism comprises two transmission rods, the transmission rods are rotatably arranged in the interior of the slide base, one end of the transmission rod is coaxially fixedly connected with the winding drum, two first spur gears are arranged below the slide base, a toothed plate is fixed on the slide rail, and the two first spur gears are engaged with the toothed plate.

[0016] In a preferred scheme, two ratchets and two circular tables are rotatably arranged on the bottom of the slide base, the circular table is fixedly connected with the first spur gear, a pawl is articulated on the bottom of the circular table, a torsion spring is arranged between the pawl and the circular table, a second spur gear is coaxially fixed on the surface of the ratchet, a third spur gear is rotatably arranged on the bottom of the slide base, the second spur gear and the third spur gear are engaged, and the third spur gear is coaxially fixedly connected with the transmission rod.

[0017] A bridge construction bridge displacement detection method is suitable for the bridge construction bridge displacement detection device, and comprises the following steps:

[0018] S1: a positioning step, the slide rail is fixed between two pier bodies through a clamp, and the two contacts on the slide base are tightly abutted on the starting measurement position of the bottom of the bridge body.

[0019] S2: scanning driving step, driving the sliding seat to move uniformly along the length direction of the slide rail, and driving the two contacts to scan along the bottom of the bridge body;

[0020] S3: differential measurement step, in the scanning process, when the two contacts move synchronously due to the vibration of the bridge body, the differential lever remains horizontal, and when the two contacts generate height difference due to the displacement deformation of the bridge body, the driving lever rotates around the hinge point;

[0021] S4: signal conversion and recording step, relying on the swing of the lever to draw a continuous detection curve with the horizontal position of the sliding seat as the horizontal coordinate and the vertical displacement difference of the bridge body as the vertical coordinate.

[0022] The bridge displacement detection device and method provided by the application have the following beneficial effects.

[0023] 1. The displacement detection mechanism is arranged, so that when the bridge body does not displace, the recorded value is a horizontal line, and when the bridge body displaces, the recorded value changes synchronously, so that the displacement of the bridge body is recorded, which is convenient for subsequent observation by the naked eye or analysis by an intelligent camera, and compared with the prior art, the vehicle is not required to be prohibited from passing when the bridge displacement is detected, so that the convenience is greatly improved.

[0024] 2. The winding and unwinding mechanism is arranged, so that when the sliding seat slides along the slide rail, the two first spur gears move synchronously with the sliding seat, the first spur gears and the toothed plate are meshed and connected, so that the two first spur gears rotate in the same direction at the same time, so as to drive the transmission rod and the winding drum to rotate, and the two winding drums are wound and unwound at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the application, and therefore should not be regarded as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0026] Figure 1 It is a schematic diagram of the overall three-dimensional structure provided by the embodiment of the application.

[0027] Figure 2 It is a schematic diagram of the structure of the slide rail and the clamp provided by the embodiment of the application.

[0028] Figure 3 It is a rear view of the rectangular frame provided by the embodiment of the application.

[0029] Figure 4 The structural schematic diagram of the slide rod and the straight slot is provided for the embodiment of the present application.

[0030] Figure 5 The structural schematic diagram of the lever is provided for the embodiment of the present application.

[0031] Figure 6 The partial sectional view of the sliding block is provided for the embodiment of the present application.

[0032] Figure 7 The exploded view of the spline sleeve and the second bevel gear is provided for the embodiment of the present application.

[0033] Figure 8 The structural schematic diagram of the lifting frame and the lead screw is provided for the embodiment of the present application.

[0034] Figure 9 The structural schematic diagram of the ratchet wheel and the pawl is provided for the embodiment of the present application.

[0035] In the figure: 1, bridge body; 2, pier body; 301, slide rail; 302, clamp; 303, slide seat; 304, rectangular frame; 305, slide rod; 306, contact; 307, slide; 308, sliding block; 309, lever; 310, reset plate; 311, first spring; 312, second spring; 313, straight slot; 314, rigid short arm; 315, slide shaft; 316, articulated rod; 317, first bevel gear; 318, support frame; 319, spline sleeve; 320, second bevel gear; 321, support seat; 322, spline shaft; 323, lead screw; 324, lifting block; 325, lifting frame; 326, recording pen; 327, support table; 328, winding drum; 329, compression roller; 401, transmission rod; 402, first spur gear; 403, toothed plate; 404, ratchet wheel; 405, circular table; 406, pawl; 407, torsional spring; 408, second spur gear; 409, third spur gear. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0037] REFERENCE Figures 1-9This invention provides a technical solution: a bridge displacement detection device and method for bridge construction, comprising a bridge body 1 and two pier bodies 2. A displacement detection mechanism is provided between the two pier bodies 2. The displacement detection mechanism includes a slide rail 301 and a rectangular frame 304. The slide rail 301 is located below the bridge body 1. Clamps 302 are bolted to both ends of the slide rail 301. The two clamps 302 are respectively bolted to the two pier bodies 2. A sliding seat 303 is slidably disposed on the surface of the slide rail 301. The rectangular frame 304 is bolted to the top of the sliding seat 303. Sliding rods 305 are slidably disposed on both vertical ends of the rectangular frame 304. A contact 306 is disposed at the top of the sliding rod 305. The contact 306 is a rolling contact. The ball bearings are set, with the top of the contact 306 abutting against the bottom of the bridge body 1. A slide rail 307 is integrally formed on the central axis of the rectangular frame 304, and a slider 308 is slidably mounted on the slide rail 307. A lever 309 is hinged to the slider 308. A reset plate 310 is fixed to the surface of the slide rod 305. A first spring 311 is set between the reset plate 310 and the rectangular frame 304, and a second spring 312 is set between the slider 308 and the rectangular frame 304. By setting a displacement detection mechanism, after the user assembles the slide rail 301 and the two clamps 302 with bolts, the two clamps 302 are fixed with bolts and pre-drilled bolt holes on the pier body 2. At this time, the two contacts 306 abut against the bottom of the bridge body 1, and the first spring 309 is fixed to the bottom of the bridge body 1. Spring 311 is currently in a compressed state. At this time, the slide block 303 is driven by an external force to move along the slide rail 301 (e.g., a ball screw assembly). With the two contacts 306 abutting against the bottom of the bridge body 1, they move along the direction of the bridge body 1. When a vehicle passes over the bridge body 1, the bridge experiences dynamic excitation such as vehicle load, causing the bridge body 1 to vibrate at high frequency and small amplitude. At this time, the two contacts 306 generate vertical reciprocating motion with the same phase and amplitude. The slider 308 moves along the slide rail 307, while the hinge point of the lever 309 remains unchanged. When the bridge body 1 undergoes permanent vertical deflection deformation due to foundation settlement, prestress loss, or long-term load, the bridge bottom outline changes. When the two contacts 306... When the bridge moves to the deformation point, a height difference is generated between the two contacts 306. At this time, the slider 308 slides on the slide rail 307, and the lever 309 rotates. The rotation angle of the lever 309 represents the height difference between the two contacts 306. While the slide block 303 moves, the recording pen 326 draws a line on the recording paper. If the bridge body 1 does not undergo displacement deformation, the recorded value is a horizontal line. When the bridge body 1 undergoes displacement deformation, the recorded value changes synchronously, thereby recording the displacement of the bridge body 1. This facilitates subsequent observation by the naked eye or analysis by a smart camera. Compared with the existing technology, it is not necessary to prohibit vehicles from passing during bridge displacement detection, which greatly improves convenience.

[0038] With reference to Figures 1-9 The straight slot 313 is arranged on the slide rod 305, and the rigid short arms 314 are arranged at the two ends of the lever 309, and the slide shafts 315 are arranged on the rigid short arms 314. The two slide shafts 315 are arranged in the straight slot 313 respectively. When the slide rod 305 moves in the vertical direction, the straight slot 313 moves in the vertical direction through the rigid short arms 314. At this time, the inner wall of the straight slot 313 extrudes the slide shaft 315, so that the slide shaft 315 drives the rigid short arm 314 to swing. The greater the displacement of the bridge, the greater the height difference between the two contacts 306, and the greater the swing angle of the lever 309.

[0039] With reference to Figures 1-9 The hinged rod 316 is hingedly connected to the inside of the sliding block 308 through a bearing, one end of the hinged rod 316 is fixedly connected with the lever 309, and the other end of the hinged rod 316 is coaxially and fixedly provided with the first bevel gear 317. The support frame 318 is fixedly arranged on the rear side of the sliding block 308 through bolts, the spline sleeve 319 is rotatably arranged on the support frame 318, the surface of the spline sleeve 319 is coaxially and fixedly provided with the second bevel gear 320, the first bevel gear 317 is meshed with the second bevel gear 320, and the support seat 321 is fixedly arranged on the rear side of the rectangular frame 304 through bolts. The spline shaft 322 is rotatably arranged on the support seat 321 through a bearing, and the spline sleeve 319 is slidably arranged on the surface of the spline shaft 322. When the lever 309 swings, the hinged rod 316 is driven to rotate, the hinged rod 316 drives the first bevel gear 317 to rotate, and the second bevel gear 320 drives the spline sleeve 319 to rotate through the meshing connection of the first bevel gear 317 and the second bevel gear 320, and the spline sleeve 319 drives the spline shaft 322 to rotate.

[0040] With reference to Figures 1-9 The spline shaft 322 is coaxially and fixedly provided with the lead screw 323, the lifting block 324 is slidably arranged on the slide 307, the lifting frame 325 is fixedly arranged on the rear side of the lifting block 324, the lifting frame 325 is threadedly arranged on the surface of the lead screw 323, and the recording pen 326 is clamped and arranged on the rear side of the lifting frame 325 through a clamping port. When the spline shaft 322 rotates, the lead screw 323 is driven to rotate through the lead screw 323, and the lifting frame 325 drives the recording pen 326 to move in the vertical direction through the threaded connection of the lead screw 323 and the lifting frame 325 and the limiting cooperation of the slide 307 and the lifting block 324. The greater the displacement of the bridge, the greater the moving stroke of the recording pen 326.

[0041] With reference to Figures 1-9The top of the sliding base 303 is fixed with two support tables 327 by bolts, the support tables 327 are provided with two winding drums 328 which rotate, the top of the sliding base 303 is provided with two pressing rollers 329 which are made of elastic material, the two pressing rollers 329 are respectively located at the two sides of the recording pen 326, one of the two winding drums 328 is provided with a recording paper which is fixed at one end and the other end is fixed to the other winding drum 328, by setting the winding drum 328, when the sliding base 303 moves, the two winding drums 328 rotate in the same direction at the same time, so that the winding drum 328 which is wound with the recording paper is unwound, the other winding drum 328 is wound, so that the recording pen 326 can record the displacement of the bridge without moving in the horizontal direction, the pressing roller 329 can always keep the tension of the recording paper by the elastic abutment with the recording paper;

[0042] With reference to Figures 1-9 The sliding base 303 is provided with a winding and unwinding mechanism, the winding and unwinding mechanism comprises two transmission rods 401 which are rotatably arranged in the inside of the sliding base 303 by bearings, one end of the transmission rod 401 is fixedly connected with the winding drum 328 in the same axis, the lower side of the sliding base 303 is provided with two first spur gears 402, the slide rail 301 is fixed with a toothed plate 403, the two first spur gears 402 are engaged with the toothed plate 403, by setting the winding and unwinding mechanism, when the sliding base 303 slides along the slide rail 301, the two first spur gears 402 move synchronously with the sliding base 303, by the engagement connection of the first spur gear 402 and the toothed plate 403, the two first spur gears 402 rotate in the same direction at the same time, so as to drive the transmission rod 401 and the winding drum 328 to rotate, realizing that the two winding drums 328 are wound and unwound at the same time;

[0043] With reference to Figures 1-9The bottom of the sliding seat 303 is rotationally provided with two ratchets 404 and two circular tables 405, the circular table 405 is fixedly connected with the first spur gear 402, the bottom of the circular table 405 is hingedly provided with a ratchet claw 406, a torsion spring 407 is arranged between the ratchet claw 406 and the circular table 405, the surface of the ratchet 404 is coaxially and fixedly provided with a second spur gear 408, the bottom of the sliding seat 303 is rotationally provided with a third spur gear 409, the second spur gear 408 and the third spur gear 409 are engaged, the third spur gear 409 is coaxially and fixedly connected with the transmission rod 401, by arranging the ratchet 404 and the ratchet claw 406, when the bridge displacement is detected, the first spur gear 402 drives the circular table 405 to rotate, at this time, the circular table 405 drives the ratchet claw 406 to rotate, the ratchet claw 406 is resisted by the ratchet on the ratchet 404, so that the ratchet 404 is simultaneously rotated, through the engagement connection of the second spur gear 408 and the third spur gear 409, the third spur gear 409 drives the transmission rod 401 to rotate, so that the two winding drums 328 simultaneously one is unwound and one is wound, after the bridge displacement detection is completed, the sliding seat 303 moves reversely, at this time, the first spur gear 402 reversely rotates, so as to drive the circular table 405 to rotate in the reverse direction, at this time, since the ratchet 404 is installed on the sliding seat 303 through the one-way bearing, the ratchet claw 406 rotates by itself, and the ratchet 404 remains stationary;

[0044] A bridge displacement detection method for bridge construction is suitable for a bridge displacement detection device for bridge construction, and comprises the following steps:

[0045] S1: a mounting and positioning step, the slide rail 301 is fixed between two pier bodies 2 through the clamp 302, so that the two contacts 306 on the sliding seat 303 are tightly abutted on the starting measurement position at the bottom of the bridge body 1;

[0046] S2: a scanning and driving step, the sliding seat 303 is uniformly driven to move along the length direction of the slide rail 301, so as to drive the two contacts 306 to scan along the bottom of the bridge body 1;

[0047] S3: a differential measurement step, during the scanning process, when the two contacts 306 synchronously move due to the vibration of the bridge body 1, the differential lever 309 remains horizontal, when the two contacts 306 generate a height difference due to the displacement deformation of the bridge body 1, the driving lever 309 rotates around the hinged point;

[0048] S4: a signal conversion and recording step, the continuous detection curve with the horizontal position of the sliding seat 303 as the abscissa and the vertical displacement difference of the bridge body 1 as the ordinate is drawn according to the swing of the lever 309.

[0049] Specifically, the working process or working principle of the bridge displacement detection device and method is as follows: in use, the user assembles the slide rail 301 and the two clamps 302 through bolts, and then fixes the two clamps 302 on the bridge pier body 2 through bolts and bolt holes pre-formed on the bridge pier body 2. At this time, the two contacts 306 abut against the bottom of the bridge body 1, and the first spring 311 is in a compressed state. At this time, the sliding block 303 is driven to move along the slide rail 301 (for example, a ball screw assembly) by an external force, the two first spur gears 402 move synchronously with the sliding block 303, the meshing connection between the first spur gear 402 and the toothed plate 403 enables the two first spur gears 402 to rotate in the same direction at the same time, the first spur gear 402 drives the circular truncated cone 405 to rotate, the circular truncated cone 405 drives the pawl 406 to rotate at this time, the pawl 406 abuts against the ratchet teeth on the ratchet wheel 404, thereby driving the ratchet wheel 404 to rotate at the same time, the meshing connection between the second spur gear 408 and the third spur gear 409 enables the third spur gear 409 to drive the transmission rod 401 to rotate, thereby enabling the two winding drums 328 to simultaneously perform one unwinding and one winding, and the recording pen 326 draws on the recording paper. Under the condition that the two contacts 306 abut against the bottom of the bridge body 1, they move along the direction of the bridge body 1. When a vehicle passes above the bridge body 1, the bridge bears the dynamic excitation of the vehicle load, and the bridge body 1 produces high-frequency and small-amplitude vibration. At this time, the two contacts 306 produce vertical reciprocating motion with the same phase and amplitude, and the sliding block 308 moves along the direction of the slide 307. The hinge point of the lever 309 remains unchanged. When the bridge body 1 produces permanent vertical deflection deformation due to foundation settlement, prestress loss, or long-term load, the bridge bottom contour line changes. When the two contacts 306 move to the deformation position, a height difference is generated between the two contacts 306. When the sliding rod 305 moves in the vertical direction, the straight slot 313 moves in the vertical direction. At this time, the inner wall of the straight slot 313 extrudes the sliding shaft 315, so that the sliding shaft 315 drives the rigid short arm 314 to swing. The more serious the bridge displacement deformation is, the greater the height difference between the two contacts 306 is, and the greater the swing angle of the lever 309 is. When the lever 309 swings, the hinged rod 316 rotates, the first bevel gear 317 rotates, the meshing connection between the first bevel gear 317 and the second bevel gear 320 enables the second bevel gear 320 to drive the spline sleeve 319 to rotate, the spline sleeve 319 drives the spline shaft 322 to rotate, the spline shaft 322 drives the lead screw 323 to rotate when it rotates, and the meshing connection between the lead screw 323 and the lifting frame 325, as well as the limiting cooperation between the slide 307 and the lifting block 324, enables the lifting frame 325 to drive the recording pen 326 to move in the vertical direction, thereby drawing a continuous detection curve with the horizontal position of the sliding block 303 as the abscissa and the bridge vertical displacement difference as the ordinate on the recording paper.

Claims

1. A bridge displacement detection device for bridge construction, comprising a bridge body (1) and two pier bodies (2), characterized in that: A displacement detection mechanism is provided between the two bridge pier bodies (2), the displacement detection mechanism comprising, The slide rail (301) is located below the bridge body (1). The two ends of the slide rail (301) are fixed with clamps (302). The two clamps (302) are respectively fixed on the two pier bodies (2). The surface of the slide rail (301) is slidably provided with a sliding seat (303). A rectangular frame (304) is fixed on the top of a slide block (303). A slide rod (305) is slidably provided on both vertical ends of the rectangular frame (304). A contact (306) is provided on the top of the slide rod (305). The top of the contact (306) abuts against the bottom of the bridge body (1). A slide rail (307) is integrally formed on the central axis of the rectangular frame (304). A slider (308) is slidably provided on the slide rail (307). A lever (309) is hinged on the slider (308).

2. The bridge displacement detection device for bridge construction according to claim 1, characterized in that, A reset plate (310) is fixed on the surface of the slide bar (305), a first spring (311) is provided between the reset plate (310) and the rectangular frame (304), and a second spring (312) is provided between the slider (308) and the rectangular frame (304).

3. The bridge displacement detection device for bridge construction according to claim 1, characterized in that, The slide bar (305) is fixed with a straight groove (313), and both ends of the lever (309) are fixed with rigid short arms (314). The rigid short arms (314) are fixed with sliding shafts (315), and the two sliding shafts (315) are respectively slidably disposed inside the straight groove (313).

4. A bridge displacement detection device for bridge construction according to claim 1, characterized in that, The slider (308) is internally hinged with a hinge rod (316). One end of the hinge rod (316) is fixedly connected to the lever (309). The other end of the hinge rod (316) is coaxially fixed with a first bevel gear (317). A support frame (318) is fixedly mounted on the rear side of the slider (308). A spline sleeve (319) is rotatably mounted on the support frame (318). A second bevel gear (320) is coaxially fixed on the surface of the spline sleeve (319). The first bevel gear (317) and the second bevel gear (320) mesh with each other.

5. A bridge displacement detection device for bridge construction according to claim 4, characterized in that, A support base (321) is fixedly provided on the rear side of the rectangular frame (304), and a spline shaft (322) is rotatably provided on the support base (321). The spline sleeve (319) is slidably sleeved on the surface of the spline shaft (322).

6. A bridge displacement detection device for bridge construction according to claim 5, characterized in that, A lead screw (323) is coaxially fixed at the bottom of the spline shaft (322), a lifting block (324) is slidably arranged on the slide rail (307), a lifting frame (325) is fixedly arranged on the rear side of the lifting block (324), the lifting frame (325) is threaded onto the surface of the lead screw (323), and a recording pen (326) is arranged on the rear side of the lifting frame (325).

7. A bridge displacement detection device for bridge construction according to claim 6, characterized in that, The top of the slide (303) is fixed with two support platforms (327), and a roller (328) is rotatably mounted on the support platform (327). The top of the slide (303) is provided with two pressure rollers (329), which are located on both sides of the recording pen (326).

8. A bridge displacement detection device for bridge construction according to claim 7, characterized in that, The slide block (303) is provided with a winding and unwinding mechanism, which includes two transmission rods (401). The transmission rods (401) are rotatably disposed inside the slide block (303). One end of the transmission rod (401) is coaxially and fixedly connected to the drum (328). Two first spur gears (402) are provided below the slide block (303). A toothed plate (403) is fixed on the slide rail (301). Both first spur gears (402) mesh with the toothed plate (403).

9. A bridge displacement detection device for bridge construction according to claim 8, characterized in that, The bottom of the slide (303) is rotatably provided with two ratchet wheels (404) and two frustums (405). The frustums (405) are fixedly connected to the first spur gear (402). The bottom of the frustums (405) is hinged with a pawl (406). A torsion spring (407) is provided between the pawl (406) and the frustums (405). The surface of the ratchet wheel (404) is coaxially fixed with a second spur gear (408). The bottom of the slide (303) is rotatably provided with a third spur gear (409). The second spur gear (408) and the third spur gear (409) mesh with each other. The third spur gear (409) is coaxially fixedly connected to the transmission rod (401).

10. A method for detecting bridge displacement during bridge construction, applicable to the bridge displacement detection device described in any one of claims 1-9, characterized in that, Includes the following steps: S1: Installation and positioning steps: Fix the slide rail (301) between the two pier bodies (2) with clamps (302), so that the two contacts (306) on the slide block (303) are tightly abutted against the starting measurement position at the bottom of the bridge body (1); S2: Scan driving step, drive slide (303) to move at a constant speed along the length direction of slide rail (301), drive two contacts (306) to scan along the bottom of bridge body (1); S3: Differential measurement steps. During the scanning process, when the two contacts (306) move synchronously due to the vibration of the bridge body (1), the differential lever (309) remains horizontal. When the two contacts (306) generate a height difference due to the displacement deformation of the bridge body (1), the lever (309) is driven to rotate around the hinge point. S4: Signal conversion and recording steps rely on the swing of lever (309) to draw a continuous detection curve with the horizontal position of slide (303) as the abscissa and the vertical displacement difference of bridge body (1) as the ordinate.

Images