Repeated moving wheel load loading test platform for simulating bridge deck fatigue and use method

Abstract

The invention provides a repeated moving wheel load loading test platform for simulating bridge deck fatigue and a use method, the repeated moving wheel load loading test platform for simulating bridge deck fatigue comprises a simulation bridge body device and a foundation, the simulation bridge body device comprises a bridge deck structure test piece, and the simulation bridge body device further comprises a simulation vehicle moving device; the simulation vehicle moving device comprises a moving wheel loading system, a guide rail supporting system and a variable frequency motor. The using method comprises the following steps that firstly, the large steel wheels in the moving wheel loading system are embedded into the steel guide rails; secondly, the height of a transverse linkage beam is adjusted through a connecting hole plate and a bolt set, pressure is applied through a steel cushion block, and the compression amount of a spring in a shock absorption assembly is adjusted so that a large steel wheel can make light contact with a steel guide rail; and thirdly, the variable frequency motor is connected with the movable wheel loading system through a crank connecting rod device, and the variable frequency motor is started to make the movable wheel loading system reciprocate. The device is novel in conception and ingenious in design, more accurately simulates the rolling fatigue loading effect of the wheels on the bridge deck structure, and has both economical efficiency and practicability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bridge engineering, in particular to a repeated moving wheel load loading test platform for simulating bridge deck fatigue and a use method thereof. BACKGROUND

[0002] With the sustained growth of the national economy, the road traffic flow and vehicle load have increased significantly. Under this heavy traffic condition, bridge deck structures such as concrete bridge deck slabs and orthotropic steel bridge deck slabs generally face severe fatigue deterioration problems. Improving the durability of bridge deck structures, prolonging their service life and ensuring the overall safety of bridges have become key tasks that need to be solved urgently.

[0003] At present, numerical simulation technology still faces many challenges in structural fatigue analysis, such as high-cycle calculation model evolution logic, fine analysis of local stress, accurate simulation of residual stress, reasonable consideration of multi-axial fatigue effect, reasonable representation of material fatigue model and reliable evaluation of fatigue life, etc. At present, there are three types of bridge deck structure fatigue loading equipment that can be used to simulate the wheel passing effect:

[0004] (1) Multi-actuator phase difference sequential loading: This method sets the phase difference between multiple actuators to simulate the continuous passing of wheels by discrete loading. The main limitation is that the loading is discontinuous, only approximate simulation of wheel passing can be achieved, and further consideration of the most unfavorable load effect caused by local stress is not possible.

[0005] (2) Pavement accelerated test device: mainly used for pavement accelerated test design, but its small wheel load and low frequency characteristics make the test period and cost difficult to bear, so there is no practical application report.

[0006] (3) Wheel load walking type fatigue test machine: Japan developed various types of wheel load walking type fatigue test machines in the 1990s. Although this type of equipment has promoted the research of bridge deck fatigue, its quantity in Japan is limited and has not been standardized, the equipment manufacturing cost is high, the energy consumption is large during operation and the maintenance cost is high, resulting in high overall test cost and poor economic efficiency. SUMMARY

[0007] In view of the problems existing in the prior art, the present application aims to provide a repeated moving wheel load loading test platform for simulating bridge deck fatigue and a use method thereof, which can more accurately simulate the rolling fatigue loading effect of wheels on bridge deck structures and ensure that the load application scheme has both economy and practicality.

[0008] In order to achieve the above object, the application provides a repeated moving wheel load test platform for simulating bridge deck fatigue, which comprises a simulated bridge body device and a foundation, the simulated bridge body device comprises a bridge deck structure test piece, the bridge deck structure test piece is installed on the foundation, and the repeated moving wheel load test platform further comprises a simulated vehicle moving device, the simulated vehicle moving device comprises a moving wheel load system, a guide rail support system and a variable frequency motor.

[0009] The variable frequency motor is connected with the moving wheel load system through a crank connecting rod device, the guide rail support system comprises vertical upright counterforce beams which are fixed to the foundation and are distributed in a matrix, a horizontal connection beam for sleeving a support unit is fixedly installed on the vertical upright counterforce beams through an adjustable height connecting hole plate and a bolt set, two longitudinal counterforce beams are installed in the support unit in parallel and are located below the horizontal connection beam, and a steel guide rail is embeddedly installed in each longitudinal counterforce beam through a filling block fixed between the horizontal connection beam and the longitudinal counterforce beam.

[0010] The moving wheel load system comprises loading wheels, an isolation bed plate and large steel wheels, the loading wheels are installed below the isolation bed plate, a steel cushion block is applied above the isolation bed plate for providing vertical pressure required by the test, limiters are installed around the steel cushion block for limiting, positioning frames are welded at four corners below the isolation bed plate, the large steel wheels are horizontally installed outside the positioning frames, and all the large steel wheels can realize light contact on the steel guide rail by adjusting the spring compression amount of the shock absorbing assembly, and most of the pressure generated by the steel cushion block is transmitted to the bridge deck structure test piece through the loading wheels.

[0011] As a preferred solution of the above solution, the inner side end of the large steel wheel is fixed to one end of a rotary leveling unit, the other end of the rotary leveling unit is rotatably installed in the positioning frame, the inner side end of the shock absorbing assembly is obliquely inserted into the positioning frame and connected with the rotary leveling unit, the outer side end of the shock absorbing assembly is gradually obliquely upward, the lower end of the spring of the shock absorbing assembly is pressed on the inclined surface of the positioning frame, and the upper end of the spring is locked on the shaft rod of the shock absorbing assembly through a nut.

[0012] Further preferably, the loading wheels adopt rubber wheels or steel wheels, and form a single-axle single-wheel loading group, a single-axle double-wheel loading group or a multi-axle double-wheel loading group.

[0013] Further preferably, the crank connecting rod device comprises a crank and a connecting rod, the connecting rod is adapted to test platforms with different lengths by being inserted into multiple independent connecting holes on the crank at different positions.

[0014] Further preferably, the limiters are six in total, four of which are installed at four corners of the isolation bed plate and are in an "L" shape, and the remaining two are installed between the longer sides of the isolation bed plate and are in a rectangular shape.

[0015] Further preferably, the support unit is sleeved and fixed on the horizontal connection beam by means of a steel frame beam structure which penetrates through the front, back, left and right.

[0016] Further preferably, the simulated bridge body device further comprises an I-beam girder and a concrete base, the concrete base is connected with the foundation, the upper end flange of the I-beam girder is fixedly connected with the bridge deck structure test piece, and the lower end flange is fixedly connected with the concrete base.

[0017] Meanwhile, the application also provides a use method of the repeated moving wheel load loading test platform for simulating the fatigue performance of the bridge deck structure, comprising the following steps:

[0018] The first step is to embed the large steel wheel in the steel guide rail, at this time, the moving wheel load system is in an empty load state, and the large steel wheel can only move longitudinally;

[0019] The second step is to adjust the height of the transverse connecting beam through the connecting hole plate and the bolt set, so that the large steel wheel in the moving wheel load system is in contact with the bridge deck structure test piece and exerts pressure through the steel cushion block, and the compression amount of the spring in the shock avoidance assembly is adjusted so that the large steel wheel is in light contact on the steel guide rail, and most of the pressure generated by the steel cushion block is transmitted to the bridge deck structure test piece through the loading wheel;

[0020] The third step is that the variable frequency motor is connected with the moving wheel load system through the crank connecting rod device, and the variable frequency motor is started to make the moving wheel load system reciprocate.

[0021] The application has the following beneficial effects:

[0022] (1) The variable frequency motor is connected with the moving wheel load system through the crank connecting rod device, the reciprocating motion of the moving wheel load system is realized, the continuity of loading is ensured, the light contact of all the large steel wheels on the steel guide rail is realized by adjusting the compression amount of the spring of the shock avoidance assembly, and the simulation reality of the wheel and bridge interaction is effectively improved;

[0023] (2) The transverse connecting beam is fixedly installed through the connecting hole plate and the bolt set with adjustable height, is suitable for test platforms with different heights, and exerts the steel cushion block above the isolation bed plate to provide the required vertical pressure in the test, realizes convenient assembly of the device, and ensures that the load application scheme has both economy and practicability.

[0024] In summary, the application has the following advantages: novel concept, ingenious design, effectively improved simulation reality of the wheel and bridge interaction, convenient assembly of the device, load application scheme with both economy and practicability, significantly reduced construction difficulty, and easy implementation. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is the overall installation device diagram of the application.

[0026] Figure 2 is the structure diagram of the moving wheel load system of the application.

[0027] Figure 3 is the installation completion diagram of the simulated bridge device and the guide rail support system in the application.

[0028] Figure 4 This is a side view of the simulated bridge device and guide rail support system in this invention.

[0029] Figure 5 The present invention is a test specimen of a bridge deck structure with the loading wheels not in contact with the overall installation device.

[0030] Figure 6 In this invention, the variable frequency motor is connected to the mobile wheel-mounted system via a crank-connecting rod device. Detailed Implementation

[0031] like Figures 1-6 As shown, a repeated moving wheel load test platform for simulating the fatigue performance of bridge deck structures includes a simulated bridge body device and a foundation 6. The simulated bridge body device includes a bridge deck structure specimen 5, which is installed on the foundation 6. Preferably, the simulated bridge body device also includes an I-beam main beam 7 and a concrete base 8. The concrete base 8 is connected to the foundation 6. The upper flange of the I-beam main beam 7 is fixedly connected to the bridge deck structure specimen 5, and the lower flange is fixedly connected to the concrete base 8.

[0032] A test platform for repeated moving wheel load to simulate the fatigue performance of bridge deck structures also includes a simulated vehicle moving device, which includes a moving wheel load system 1, a guide rail support system 2, and a variable frequency motor 3.

[0033] The variable frequency motor 3 is connected to the mobile wheel-mounted system 1 through a crank-connecting rod device. The crank-connecting rod device includes a crank 31 and a connecting rod 32. The connecting rod 32 is adapted to test platforms of different lengths by being inserted into multiple independent connecting holes on the crank 31 at different positions.

[0034] The guide rail support system 2 includes vertical reaction beams 25 fixed to the foundation 6 and distributed in a matrix. A transverse connecting beam 24 is fixedly installed on the vertical reaction beam 25 through an adjustable height connecting plate 26 and a bolt group 27. A support unit 23 is fitted on the transverse connecting beam 24. Preferably, the support unit 23 is a steel frame beam structure that runs through the front, back, left and right sides.

[0035] Two longitudinal reaction beams 21 are installed in parallel within the support unit 23 and located below the transverse connecting beam 24. They are fixed by padding blocks 28 between the transverse connecting beam 24 and the longitudinal reaction beams 21, and each longitudinal reaction beam 21 is embedded with a steel guide rail 22.

[0036] The mobile wheel-mounted system 1 includes loading wheels 12, isolation bed 15 and large steel wheels 11. The loading wheels 12 are installed under the isolation bed 15 and steel pads 16 are applied above the isolation bed 15 to provide the vertical pressure required for the test. The loading wheels 12 are made of rubber wheels or steel wheels, forming a single-axle single-wheel loading group, a single-axle double-wheel loading group or a multi-axle double-wheel loading group.

[0037] The position limiter 17 is installed around the steel pad 16 for position limiting. Preferably, there are six position limiters 17, four of which are installed at the four corners of the isolation bedplate 15 in "L" shape, and the remaining two are installed between the longer sides of the isolation bedplate 15 in rectangular shape.

[0038] The positioning frame 14 is welded at the four corners below the isolation bedplate 15. The large wheels 11 are horizontally installed outside the positioning frame 14, and can be in light contact with the steel rail 22 by adjusting the compression amount of the spring of the shock absorbing assembly 13, and the pressure generated by the steel pad 16 is mostly transmitted to the bridge structure test piece 5 through the loading wheel 12. Preferably, the inner side end of the large wheel 11 is fixed to one end of the rotary leveling unit 18, the other end of the rotary leveling unit 18 is rotatably installed in the positioning frame 14, the inner side end of the shock absorbing assembly 13 is obliquely inserted into the positioning frame 14 and connected to the rotary leveling unit 18, the outer side end of the shock absorbing assembly 13 is gradually inclined upward, the lower end of the spring of the shock absorbing assembly 13 is pressed on the inclined surface of the positioning frame 14, and the upper end of the spring is locked on the shaft of the shock absorbing assembly 13 through a nut.

[0039] A method for using the repeated moving wheel load test platform for simulating the fatigue performance of a bridge structure as described above, comprising the following steps:

[0040] The first step is to embed the large wheels 11 in the steel rail 22 in the moving wheel load system 1, at this time the moving wheel load system 1 is in an empty state and the large wheels 11 can only move longitudinally;

[0041] The second step is to adjust the height of the transverse connecting beam 24 through the connecting hole plate 26 and the bolt set 27, so that the large wheels 11 in the moving wheel load system 1 are in contact with the bridge structure test piece 5 and apply pressure through the steel pad 16, and the compression amount of the spring in the shock absorbing assembly 13 is adjusted so that the large wheels 11 are in light contact with the steel rail 22, and the pressure generated by the steel pad 16 is mostly (more than 90%) transmitted to the bridge structure test piece 5 through the loading wheel 12;

[0042] The third step is to connect the moving wheel load system 1 through the crank connecting rod device by the variable frequency motor 3, and start the variable frequency motor 3 to make the moving wheel load system 1 reciprocate.

Claims

1. A repeated moving wheel load test platform for simulating fatigue performance of a bridge deck structure, comprising a simulated bridge body device and a foundation (6), the simulated bridge body device comprising a bridge deck structure test piece (5), the bridge deck structure test piece (5) being installed on the foundation (6), characterized in that: Also include a simulation vehicle moving device, the simulation vehicle moving device includes a moving wheel load system (1), a guide rail support system (2) and a variable frequency motor (3); The variable frequency motor (3) is connected with the moving wheel load system (1) through a crank connecting rod device, the guide rail support system (2) includes vertical vertical counterforce beams (25) fixed with the foundation (6) and matrix distribution, the vertical vertical counterforce beams (25) are fixedly installed with the horizontal contact beams (24) for supporting units (23) through the adjustable height connecting hole plates (26) and bolt groups (27), two longitudinal counterforce beams (21) are installed in the supporting units (23) and are located below the horizontal contact beams (24), the longitudinal counterforce beams (21) are embeddedly installed with the steel guide rails (22) through the filling blocks (28) fixed between the horizontal contact beams (24) and the longitudinal counterforce beams (21). The moving wheel load system (1) includes loading wheels (12), isolation bed plates (15) and large steel wheels (11), the loading wheels (12) are installed below the isolation bed plates (15), and steel pads (16) are applied above the isolation bed plates (15) to provide the vertical pressure required by the test, limiters (17) are installed around the steel pads (16) to limit, positioning frames (14) are welded at four corners below the isolation bed plates (15), the large steel wheels (11) are horizontally installed outside the positioning frames (14), and all the large steel wheels (11) can be lightly contacted on the steel guide rails (22) by adjusting the spring compression amount of the shock avoidance assembly (13), and most of the pressure generated by the steel pads (16) is transmitted to the bridge deck structure test piece (5) through the loading wheels (12).

2. The moving wheel load test platform for simulating fatigue performance of bridge deck structure according to claim 1, characterized in that: The inner side end of the large steel wheel (11) is fixed at one end of the rotary leveling unit (18), the other end of the rotary leveling unit (18) is rotatably installed in the positioning frame (14), the inner side end of the shock avoidance assembly (13) is obliquely inserted into the positioning frame (14) and connected with the rotary leveling unit (18), the outer side end of the shock avoidance assembly (13) is gradually inclined upward, the lower end of the spring of the shock avoidance assembly (13) is pressed on the inclined surface of the positioning frame (14), and the upper end of the spring is locked on the shaft rod of the shock avoidance assembly (13) through a nut.

3. The moving wheel load test platform for simulating fatigue performance of bridge deck structure according to claim 1, characterized in that: The loading wheels (12) adopt rubber wheels or steel wheels, and form single-axle single-wheel loading groups, single-axle double-wheel loading groups or multi-axle double-wheel loading groups.

4. The moving wheel load test platform for simulating bridge fatigue according to claim 1, wherein: The crank connecting rod device includes a crank (31) and a connecting rod (32), the connecting rod (32) is adapted to test platforms of different lengths by being inserted into multiple independent connecting holes on the crank (31) at different positions.

5. The moving wheel load test platform for simulating bridge fatigue according to claim 1, wherein: The limiters (17) are six in total, four of which are installed at four corners of the isolation bed plates (15) and are in the shape of "L", and the remaining two are installed between the longer sides of the isolation bed plates (15) and are in the shape of rectangle.

6. The moving wheel load test platform for simulating bridge fatigue according to claim 1, wherein: The supporting units (23) are fixed on the horizontal contact beams (24) by being sleeved with steel frame beam structures penetrating through front, back, left and right.

7. The moving wheel load test platform for simulating bridge fatigue according to claim 1, wherein: The simulation bridge device further comprises an I-beam girder (7) and a concrete base (8), the concrete base (8) is connected with the foundation (6), the upper end flange of the I-beam girder (7) is fixedly connected with the bridge deck structure test piece (5), and the lower end flange is fixedly connected with the concrete base (8).

8. A method of using the moving wheel load test platform for simulating the fatigue performance of a bridge deck structure according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: Firstly, embed the large steel wheel (11) in the steel guide rail (22), at this time the mobile wheel load system (1) is in empty load and the large steel wheel (11) can only move longitudinally; Secondly, adjust the height of the transverse connecting beam (24) through the connecting hole plate (26) and the bolt set (27), so that the large steel wheel (11) in the mobile wheel load system (1) is in contact with the bridge deck structure test piece (5) and exerts pressure through the steel cushion block (16), and the compression amount of the spring in the shock avoidance assembly (13) is adjusted so that the large steel wheel (11) is in light contact on the steel guide rail (22), and the pressure generated by the steel cushion block (16) is mostly transmitted to the bridge deck structure test piece (5) through the loading wheel (12); Thirdly, connect the mobile wheel load system (1) through the crank connecting rod device, start the variable frequency motor (3) to make the mobile wheel load system (1) reciprocate.

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