An experimental device and experimental method for the friction coefficient after the installation of a rotating body bridge spherical hinge

Abstract

This application belongs to the technical field of bridge engineering and discloses an experimental device and an experimental method for the friction coefficient after the installation of a rotating bridge spherical hinge, including a cross-shaped reaction frame, a support steel cylinder, an active pressure jack, and a tension and compression dual-action jack. The vertical rotation of the spherical hinge is realized through the active pressure jack and the tension and compression dual-action jack, and an experimental method for the friction coefficient of the rotating spherical hinge is developed. Using this method, the friction coefficient can be experimentally determined after the installation of the spherical hinge, and then the rotation force can be accurately determined, and the reasonable drag steel strands and jack types can be configured to avoid the problem that cannot be adjusted after the pier and beam are poured.

Description

Technical Field

[0001] The present application belongs to the technical field of bridge engineering, and specifically relates to an experimental device and an experimental method for the friction coefficient of a swivel bridge ball joint after installation. Background Art

[0002] The rotation construction of the bridge is realized by the core function of the relative rotation of the upper and lower parts of the swivel ball joint. Therefore, the friction coefficient performance index after the installation of the swivel ball joint has a decisive influence on the rotation construction. The current friction coefficient is measured by weighing experiments after the upper T-structure is completed. However, even if the friction coefficient obtained in the experiment at this stage is too large, there is no possibility of adjustment. Therefore, it is necessary to develop a new experimental device and experimental method for measuring the friction coefficient. Summary of the invention

[0003] The purpose of the present application is to solve the problems of the prior art and to provide an experimental device and an experimental method for the friction coefficient of a swivel bridge after the ball joint is installed.

[0004] In order to solve the technical problem, the technical solution of the present application is: an experimental device for the friction coefficient of a swivel bridge after installation, comprising a cross-shaped reaction frame, four supporting steel cylinders, four embedded anchor bars, an active pressure jack, a fixed hinge support, four embedded pin seats, four tension and compression double-acting jacks, four movable pin hinges, four displacement meters and a control component, wherein the four reaction arms of the cross-shaped reaction frame are respectively arranged on the four supporting steel cylinders, the cross-shaped reaction frame and the four supporting steel cylinders are respectively fixed by four embedded anchor bars embedded in the edge of the lower pedestal, a ball joint is arranged at the center of the lower pedestal, and an active pressure jack is fixed at the top center of the ball joint. The top of the active pressurizing jack is connected to the bottom center of the cross-shaped reaction frame through a fixed hinge support, four embedded pin seats are respectively embedded in the top edge of the ball joint, the top of the embedded pin seat is connected to the tension and compression double-acting jack, the top of the tension and compression double-acting jack is connected to the movable pin hinge, the top of the movable pin hinge is buckled at the bottom of the reaction arm of the cross-shaped reaction frame, and four displacement meters are installed around the ball joint on the top of the lower support platform, and the connecting line relative to the two displacement meters and the connecting line relative to the two embedded pin seats are respectively parallel to the straight line where one of the reaction arms of the cross-shaped reaction frame is located, and the active pressurizing jack, tension and compression double-acting jack and displacement meter are respectively connected to the control component.

[0005] Preferably, the cross-shaped reaction frame is composed of four reaction arms cross-arranged to form a cross-box structure, and the four reaction arm bottom plates are respectively provided with sliding grooves, and the movable pin hinges can be movably buckled in the sliding grooves.

[0006] Preferably, the movable pin hinge is an I-shaped cross-section, and the movable pin hinge includes a first movable pin hinge, a second movable pin hinge, a third movable pin hinge and a fourth movable pin hinge.

[0007] Preferably, the slide groove includes a first slide groove, a second slide groove, a third slide groove and a fourth slide groove, and the tops of the first movable pin hinge, the second movable pin hinge, the third movable pin hinge and the fourth movable pin hinge correspond to the movable buckles in the first slide groove, the second slide groove, the third slide groove and the fourth slide groove respectively.

[0008] Preferably, the support steel cylinder includes a first support steel cylinder, a second support steel cylinder, a third support steel cylinder and a fourth support steel cylinder, the embedded anchor bar includes a first embedded anchor bar, a second embedded anchor bar, a third embedded anchor bar and a fourth embedded anchor bar, the embedded pin seat includes a first embedded pin seat, a second embedded pin seat, a third embedded pin seat and a fourth embedded pin seat, the displacement meter includes a first displacement meter, a second displacement meter, a third displacement meter and a fourth displacement meter, the first embedded anchor bar and the second embedded anchor bar are coaxially connected to the first support steel cylinder and the second support steel cylinder respectively, the first embedded anchor bar and the second embedded anchor bar are coaxially connected to the first support steel cylinder and the second support steel cylinder respectively, and the first embedded anchor bar and the second embedded anchor bar are coaxially connected to the first support steel cylinder and the second support steel cylinder respectively. The connecting line of the first embedded anchor bar and the second embedded anchor bar is parallel to the connecting line of the first embedded pin seat and the second embedded pin seat, the connecting line of the first embedded pin seat and the second embedded pin seat is parallel to the connecting line of the first displacement meter and the second displacement meter, the third embedded anchor bar and the fourth embedded anchor bar are coaxially connected to the third supporting steel cylinder and the fourth supporting steel cylinder respectively, the connecting line of the third embedded anchor bar and the fourth embedded anchor bar is parallel to the connecting line of the third embedded pin seat and the fourth embedded pin seat, and the connecting line of the third embedded pin seat and the fourth embedded pin seat is parallel to the connecting line of the third displacement meter and the fourth displacement meter.

[0009] Preferably, the first embedded pin seat, the second embedded pin seat, the third embedded pin seat and the fourth embedded pin seat are correspondingly orthogonally arranged at a radius of 3 / 4 from the center of the spherical joint plane.

[0010] Preferably, the installation method of the experimental device comprises the following steps:

[0011] Step 1: After the steel bars of the lower cap are tied, four pre-embedded anchor bars are embedded in the lower cap at the positions corresponding to the cross-shaped reaction frame cable holes;

[0012] Step 2: Install four embedded pin seats corresponding to the edge of the ball joint, and then pour the concrete of the lower cap and the ball joint;

[0013] Step 3: After the concrete reaches the required strength, install four supporting steel cylinders and a cross-shaped reaction frame in sequence, and lock the cross-shaped reaction frame with four embedded anchor bars;

[0014] Step 4: Install the active pressure jack at the center of the ball joint, and connect it to the bottom center of the cross-shaped reaction frame through a fixed hinge support. Install four tension-compression double-acting jacks at the four embedded pin seats respectively. The lower end of the tension-compression double-acting jack is pin-connected with the embedded pin seat, and the upper end of the tension-compression double-acting jack is pin-connected with the movable pin hinge. The top of the movable pin hinge is buckled at the bottom of the reaction arm of the cross-shaped reaction frame.

[0015] Step 5: Install four displacement gauges around the spherical hinge for measuring the pressure value or the tensile force value.

[0016] Preferably, an experimental method for the friction coefficient after installation of a rotating bridge spherical hinge is used for the implementation of the experimental device for the friction coefficient after installation of a rotating bridge spherical hinge as described above, and includes the following steps:

[0017] Step 1: Select two opposite tension-compression double-acting jacks as the experimental axis, and apply pressure with the active pressure jack N , and apply equal pressure with the other two tension-compression double-acting jacks perpendicular to the experimental axis F ;

[0018] Step 2: Apply a downward pressure with one of the tension-compression double-acting jacks on the experimental axis, and apply an upward tensile force with the other tension-compression double-acting jack. The force values are equal and the directions are opposite. Increase the pressure value and the tensile force value step by step by 1 kN, synchronously record the displacement values of the corresponding displacement gauges, and plot the force-displacement curve; after the force-displacement curve shows an inflection point, record the pressure value F 1 and the tensile force value F 2, and the first group of experiments is completed;

[0019] Step 3: Apply forces in the opposite directions with the two tension-compression double-acting jacks on the experimental axis until the force-displacement curve shows an inflection point again, and record F 1’, F 2’, and the second group of experiments is completed;

[0020] Step 4: Select the other two tension-compression double-acting jacks as the new experimental axis, measure the displacement values with the corresponding displacement gauges, and complete the third and fourth groups of experiments according to Steps 2 and 3 to obtain F 3, F 4, F 3’, F 4’;

[0021] Step 5: Calculate the friction coefficient of the spherical hinge through the pressure values and tensile force values obtained in Steps 2 to 4.

[0022] Preferably, the specific content of Step 5 is:

[0023] Assume that the self-weight of the upper half of the spherical hinge is G , the spherical radius of the spherical hinge is R , the plane radius is r , and the distances from the two opposite tension-compression double-acting jacks to the center of the spherical hinge are L 1, L 2. For the first group of experiments, calculate the friction coefficient:

[0024] Half opening angle of the spherical crown of the friction surface: ;

[0025] Maximum experimental frictional torque: ;

[0026] Total vertical load on the friction surface: ;

[0027] Coefficient of friction: ;

[0028] Four groups of coefficients of friction are obtained by grouped calculation μ 1, μ 2, μ 3, μ 4;

[0029] Coefficient of friction of spherical hinge: .

[0030] Compared with the prior art, the advantages of the present application are as follows:

[0031] (1) The present application proposes an experimental device for the coefficient of friction after the installation of a spherical hinge of a rotating bridge, including a cross-shaped reaction frame, a supporting steel cylinder, an active pressure jack, and a tension-compression dual-action jack. The vertical rotation of the spherical hinge is realized through the active pressure jack and the tension-compression dual-action jack, and an experimental method for the coefficient of friction of the rotating spherical hinge is developed. By using this method, the coefficient of friction can be experimentally measured after the installation of the spherical hinge, and then the rotation force can be accurately determined, and the reasonable drag steel strands and jack types can be configured to avoid the problem that cannot be adjusted after the pier and beam are poured;

[0032] (2) The present application discloses an experimental method for the coefficient of friction after the installation of a spherical hinge of a rotating bridge. First, two opposite tension-compression dual-action jacks are selected as the experimental axes, and the active pressure jack applies pressure N , and the other two tension-compression dual-action jacks perpendicular to the experimental axis apply equal pressure F . One of the tension-compression dual-action jacks on the experimental axis applies a downward pressure, and the other tension-compression dual-action jack applies an upward tension. The force values are equal and the directions are opposite. By cooperating with the force-displacement curve to obtain the inflection point, the obtained maximum frictional torque is more accurate;

[0033] (3) The method of the present application obtains four groups of coefficients of friction through four tension-compression dual-action jacks μ 1, μ 2, μ 3, μ 4, and after averaging, the coefficient of friction of the spherical hinge obtained is more accurate, reducing the experimental error. Description of the drawings

[0034] Figure 1 is a schematic three-dimensional structure diagram of an experimental device for the coefficient of friction after the installation of a spherical hinge of a rotating bridge according to the present application;

[0035] Figure 2Schematic cross-sectional structure diagram of an experimental device for the friction coefficient after the installation of a rotating bridge spherical hinge in this application;

[0036] Figure 3 Partial top view structure diagram of an experimental device for the friction coefficient after the installation of a rotating bridge spherical hinge in this application;

[0037] Figure 4 Schematic structure diagram of the cross-shaped reaction frame in this application;

[0038] Figure 5 Calculation principle diagram of an experimental method for the friction coefficient after the installation of a rotating bridge spherical hinge in this application.

[0039] Explanation of reference numerals:

[0040] 1. Cross-shaped reaction frame, 2. Support steel cylinder, 3. Embedded anchor bar, 4. Active pressure jack, 5. Fixed hinge support, 6. Embedded pin seat, 7. Pull-press dual-action jack, 8. Movable pin hinge, 9. Displacement meter, 10. Lower bearing platform, 11. Spherical hinge;

[0041] 1-1. Reaction arm;

[0042] 1-1-1. First chute, 1-1-2. Second chute, 1-1-3. Third chute, 1-1-4. Fourth chute;

[0043] 2-1. First support steel cylinder, 2-2. Second support steel cylinder, 2-3. Third support steel cylinder, 2-4. Fourth support steel cylinder;

[0044] 3-1. First embedded anchor bar, 3-2. Second embedded anchor bar, 3-3. Third embedded anchor bar, 3-4. Fourth embedded anchor bar;

[0045] 6-1. First embedded pin seat, 6-2. Second embedded pin seat, 6-3. Third embedded pin seat, 6-4. Fourth embedded pin seat;

[0046] 8-1. First movable pin hinge, 8-2. Second movable pin hinge, 8-3. Third movable pin hinge, 8-4. Fourth movable pin hinge;

[0047] 9-1. First displacement meter, 9-2. Second displacement meter, 9-3. Third displacement meter, 9-4. Fourth displacement meter. Detailed implementation method

[0048] The present application will be described in detail below in conjunction with the accompanying drawings and specific embodiments, but the present application is not limited to these embodiments. The present application covers any alternatives, modifications, equivalent methods, and solutions made within the essence and scope of the present application. In order to enable the public to have a thorough understanding of the present application, specific details are described in detail in the following embodiments of the present application, and those skilled in the art can fully understand the present application without these detailed descriptions.

[0049] Embodiment 1

[0050] As Figures 1 - 4 shown, the present application discloses an experimental device for the friction coefficient after the installation of a rotating body bridge spherical hinge, including a cross-shaped reaction frame 1, four support steel cylinders 2, four embedded anchor bars 3, an active pressure jack 4, a fixed hinge support 5, four embedded pin seats 6, four tension-compression dual-action jacks 7, four movable pin hinges 8, four displacement gauges 9, and a control component. The four reaction arms 1-1 of the cross-shaped reaction frame 1 are respectively arranged on the four support steel cylinders 2, and the cross-shaped reaction frame 1 and the four support steel cylinders 2 are respectively fixed by the four embedded anchor bars 3 embedded at the edge of the lower bearing platform 10. A spherical hinge 11 is arranged at the center position of the lower bearing platform 10, and the center of the top of the spherical hinge 11 is fixed with an active pressure jack 4. The top of the active pressure jack 4 is connected to the center of the bottom of the cross-shaped reaction frame 1 through a fixed hinge support 5. Four embedded pin seats 6 are respectively embedded at the top edge of the spherical hinge 11. The top of the embedded pin seat 6 is connected to a tension-compression dual-action jack 7, and the top of the tension-compression dual-action jack 7 is connected to a movable pin hinge 8. The top of the movable pin hinge 8 is buckled to the bottom of the reaction arm 1-1 of the cross-shaped reaction frame 1. Four displacement gauges 9 are installed around the spherical hinge 11 on the top of the lower bearing platform 10. The connection lines of the opposite two displacement gauges 9 and the connection lines of the opposite two embedded pin seats 6 are respectively parallel to the straight line where one of the reaction arms 1-1 of the cross-shaped reaction frame 1 is located. The active pressure jack 4, the tension-compression dual-action jack 7, and the displacement gauge 9 are respectively connected to the control component.

[0051] Embodiment 2

[0052] Preferably, as Figure 4 shown, the cross-shaped reaction frame 1 is composed of four cross-shaped reaction arms 1-1 arranged in a cross-shaped box structure. Sliding grooves are respectively opened on the bottom plates of the four reaction arms 1-1, and the movable pin hinge 8 can be movably buckled in the sliding grooves.

[0053] Preferably, as Figure 4 shown, the movable pin hinge 8 has an I-shaped cross-section, and the movable pin hinge 8 includes a first movable pin hinge 8-1, a second movable pin hinge 8-2, a third movable pin hinge 8-3, and a fourth movable pin hinge 8-4.

[0054] Preferably, as Figure 4As shown, the chute includes a first chute 1-1-1, a second chute 1-1-2, a third chute 1-1-3, and a fourth chute 1-1-4. The tops of the first movable pin hinge 8-1, the second movable pin hinge 8-2, the third movable pin hinge 8-3, and the fourth movable pin hinge 8-4 are respectively and movably latched in the first chute 1-1, the second chute 1-2, the third chute 1-3, and the fourth chute 1-4.

[0055] Embodiment 3

[0056] Preferably, as Figure 3 shown, the support steel cylinder 2 includes a first support steel cylinder 2-1, a second support steel cylinder 2-2, a third support steel cylinder 2-3, and a fourth support steel cylinder 2-4. The embedded anchor bars 3 include a first embedded anchor bar 3-1, a second embedded anchor bar 3-2, a third embedded anchor bar 3-3, and a fourth embedded anchor bar 3-4. The embedded pin seats 6 include a first embedded pin seat 6-1, a second embedded pin seat 6-2, a third embedded pin seat 6-3, and a fourth embedded pin seat 6-4. The displacement gauges 9 include a first displacement gauge 9-1, a second displacement gauge 9-2, a third displacement gauge 9-3, and a fourth displacement gauge 9-4. The first embedded anchor bar 3-1 and the second embedded anchor bar 3-2 are coaxially connected to the first support steel cylinder 2-1 and the second support steel cylinder 2-2 respectively. The line connecting the first embedded anchor bar 3-1 and the second embedded anchor bar 3-2 is parallel to the line connecting the first embedded pin seat 6-1 and the second embedded pin seat 6-2. The line connecting the first embedded pin seat 6-1 and the second embedded pin seat 6-2 is parallel to the line connecting the first displacement gauge 9-1 and the second displacement gauge 9-2. The third embedded anchor bar 3-3 and the fourth embedded anchor bar 3-4 are coaxially connected to the third support steel cylinder 2-3 and the fourth support steel cylinder 2-4 respectively. The line connecting the third embedded anchor bar 3-3 and the fourth embedded anchor bar 3-4 is parallel to the line connecting the third embedded pin seat 6-3 and the fourth embedded pin seat 6-4. The line connecting the third embedded pin seat 6-3 and the fourth embedded pin seat 6-4 is parallel to the line connecting the third displacement gauge 9-3 and the fourth displacement gauge 9-4.

[0057] The line connecting the first embedded anchor bar 3-1 and the second embedded anchor bar 3-2 passes through the center of the active pressure jack 4.

[0058] The line connecting the third embedded anchor bar 3-3 and the fourth embedded anchor bar 3-4 passes through the center of the active pressure jack 4.

[0059] Preferably, as Figure 2 、 3 shown, the first embedded pin seat 6-1, the second embedded pin seat 6-2, the third embedded pin seat 6-3, and the fourth embedded pin seat 6-4 are orthogonally arranged at a distance of 3 / 4 of the radius from the center of the plane of the spherical hinge 11.

[0060] Embodiment 4

[0061] Preferably, as Figure 1 and 2 shown, the installation method of the experimental device includes the following steps:

[0062] Step 1: After the steel bars of the lower bearing platform 10 are tied, four embedded anchor bars 3 are pre-embedded in the lower bearing platform 10 at the positions corresponding to the cable-passing holes of the cruciform reaction frame 1;

[0063] Step 2: Four embedded pin seats 6 are installed corresponding to the edge of the spherical hinge 11, and then the concrete of the lower bearing platform 10 and the spherical hinge 11 is poured;

[0064] Step 3: After the concrete reaches the strength, four support steel cylinders 2 and the cruciform reaction frame 1 are installed in sequence, and the cruciform reaction frame 1 is locked by the four embedded anchor bars 3;

[0065] Step 4: An active pressure jack 4 is installed at the center position of the spherical hinge 11, and the bottom center of the cruciform reaction frame 1 is connected through a fixed hinge support 5. Four tension and compression dual-action jacks 7 are installed at the positions of the four embedded pin seats 6 respectively. The lower end of the tension and compression dual-action jack 7 is pin-connected to the embedded pin seat 6, and the upper end of the tension and compression dual-action jack 7 is pin-connected to a movable pin hinge 8. The top of the movable pin hinge 8 is buckled to the bottom of the reaction arm 1-1 of the cruciform reaction frame 1;

[0066] Step 5: Four displacement gauges 9 are installed around the spherical hinge 11 for measuring the pressure value or the tensile value.

[0067] Example 5

[0068] Preferably, as Figure 2 and 5 shown, an experimental method for the friction coefficient after the installation of the spherical hinge of a rotating bridge, which is used for the implementation of the experimental device for the friction coefficient after the installation of the spherical hinge of a rotating bridge as described above, includes the following steps:

[0069] Step 1: Select two relatively tension and compression dual-action jacks 7 as the experimental axes, and the active pressure jack 4 applies pressure N , and the other two tension and compression dual-action jacks 7 perpendicular to the experimental axis apply equal pressure F ;

[0070] Step 2: Initialize the force and displacement measurement. One of the tension and compression dual-action jacks 7 of the experimental axis applies a downward pressure, and the other tension and compression dual-action jack 7 applies an upward tensile force. The force values are equal and the directions are opposite. Increase the pressure value and the tensile force value step by step by 1 kN, synchronously record the displacement values of the corresponding displacement gauges 9, and draw a force-displacement curve; after the force-displacement curve shows an inflection point, record the pressure value F 1 and the tensile force value F 2, and the first group of experiments is completed;

[0071] Step 3: Apply forces in the opposite direction to the two tension-compression double-acting jacks 7 of the experimental axis until the inflection point appears again on the force-displacement curve, and record F 1’ F 2’, and the second group of experiments is completed;

[0072] Step 4: Select another two tension-compression double-acting jacks 7 as the new experimental axes, measure the displacement values with the corresponding displacement gauges 9, and complete the third and fourth groups of experiments according to Steps 2 and 3 to obtain F 3 F 4 F 3’ F 4’;

[0073] Step 5: Calculate the friction coefficient of the spherical hinge based on the pressure values and tensile force values obtained in Steps 2 to 4.

[0074] The specific content of Step 5 is as follows:

[0075] Assume that the self-weight of the upper half of the spherical hinge 11 is G , the spherical radius of the spherical hinge 11 is R , the plane radius is r , and the distance from the center of the spherical hinge 11 to the two opposite tension-compression double-acting jacks 7 is L 1 L 2. For the first group of experiments, calculate the friction coefficient:

[0076] Half opening angle of the spherical crown of the friction surface: ;

[0077] Maximum experimental frictional moment: ;

[0078] Total vertical load on the friction surface: ;

[0079] Friction coefficient: ;

[0080] Calculate the friction coefficients μ1, μ2, μ3, and μ4 in groups;

[0081] Friction coefficient of the spherical hinge: .

[0082] The self-weight of the upper half of the spherical hinge 11 includes the cast concrete and the jacks.

[0083] The working principle of this application is as follows:

[0084] As Figures 1 - 5As shown in the figure, this application proposes an experimental device for the friction coefficient after the installation of the spherical hinge of a swivel bridge, including a cross-shaped reaction frame 1, four support steel cylinders 2, four embedded anchor bars 3, an active pressure jack 4, a fixed hinge support 5, four embedded pin seats 6, four tension-compression dual-action jacks 7, four movable pin hinges 8, four displacement gauges 9 and a control component. A chute is opened on the bottom plate of the cross-shaped reaction frame 1. The movable pin hinge 8 has an I-shaped cross-section and is buckled in the chute. The installation method of the experimental device is as follows: First, after the steel bars of the lower bearing platform 10 are tied, four embedded anchor bars 3 are embedded in the lower bearing platform 10 at the positions corresponding to the cable-passing holes of the cross-shaped reaction frame 1. Secondly, four orthogonally arranged embedded pin seats 6 are installed corresponding to the circle with a radius of 3 / 4 of the spherical hinge plane center. Then, 4 groups of support steel cylinders 2, the cross-shaped reaction frame 1, and the embedded anchor bars 3 are locked in sequence. Subsequently, an active pressure jack 4 is installed at the center position of the spherical hinge 11, and 4 tension-compression dual-action jacks 7 are installed at the positions corresponding to the embedded pin seats 6. The lower ends are pin-connected to the embedded pin seats 6, and the upper ends are pin-connected to the movable pin hinges 8. Finally, 4 orthogonally arranged displacement gauges 9 are installed around the spherical hinge 11. The friction coefficient experimental method: The friction coefficient is experimentally measured in two orthogonal directions. Select the experimental axis, the active pressure jack 4 applies a pressure N, and the two jacks perpendicular to the experimental axis apply equal pressures F. The first tension-compression dual-action jack on the experimental axis applies a downward pressure, and the second tension-compression dual-action jack applies an upward pull. The force values are basically equal and in opposite directions. The pressure value and the pull value are increased step by step by 1 kN, and the displacement values of the first displacement gauge and the second displacement gauge are synchronously recorded, and a force-displacement curve is plotted. After the force-displacement curve shows an obvious inflection point, record the pressure value F 1 and the pull value F 2, and this group of experiments is completed. Then, the first tension-compression dual-action jack and the second tension-compression dual-action jack apply forces in the opposite direction until the force-displacement curve shows an inflection point again, and record F 1’, F 2’, and the second group of experiments is completed. Select the orthogonal direction as the new experimental axis, and complete the third group and the fourth group of experiments according to the above method to obtain the critical force F 3, F 4, F 3’, F 4’ for generating the rigid body rotation of the spherical hinge. Calculate the friction coefficients of the 4 groups by grouping and perform mean processing to obtain the friction coefficient of the spherical hinge.

[0085] The present application provides an experimental device for the friction coefficient after the installation of a rotating bridge spherical hinge, which includes a cross-shaped reaction frame, a support steel cylinder, an active pressure jack, and a tension-compression dual-action jack. The vertical rotation of the spherical hinge is achieved through the active pressure jack and the tension-compression dual-action jack. An experimental method for the friction coefficient of the rotating spherical hinge is developed. By using this method, the friction coefficient can be experimentally determined after the installation of the spherical hinge, and then the rotation force can be accurately determined, and the dragging steel strands and jack types can be reasonably configured to avoid the problem that cannot be adjusted after the pier and beam are cast.

[0086] The present application discloses an experimental method for the friction coefficient after the installation of a rotating bridge spherical hinge. First, two opposite tension-compression dual-action jacks are selected as the experimental axes. The active pressure jack applies a pressure N, and the other two tension-compression dual-action jacks perpendicular to the experimental axes apply equal pressures F. One of the tension-compression dual-action jacks on the experimental axis applies a downward pressure, and the other tension-compression dual-action jack applies an upward tension. The force values are equal and the directions are opposite. By cooperating with the force-displacement curve to obtain the inflection point, the maximum frictional torque obtained is more accurate.

[0087] The method of the present application obtains 4 groups of friction coefficients through four tension-compression dual-action jacks μ 1. μ 2. μ 3. μ 4. Perform mean processing to obtain a more accurate friction coefficient of the spherical hinge and reduce the experimental error.

[0088] The above has made a detailed description of the preferred embodiments of the present application. However, the present application is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can be made without departing from the purpose of the present application.

[0089] Many other changes and modifications can be made without departing from the concept and scope of the present application. It should be understood that the present application is not limited to specific embodiments, and the scope of the present application is defined by the appended claims.

Claims

1. An experimental device for the friction coefficient after the installation of a rotating body bridge spherical hinge, characterized in that: It includes a cross-shaped reaction frame (1), four support steel cylinders (2), four embedded anchor bars (3), an active pressure jack (4), a fixed hinge support (5), four embedded pin seats (6), four tension-compression dual-action jacks (7), four movable pin hinges (8), four displacement gauges (9) and a control component. The four reaction arms (1-1) of the cross-shaped reaction frame (1) are respectively arranged on the four support steel cylinders (2). The cross-shaped reaction frame (1) and the four support steel cylinders (2) are respectively fixed by four embedded anchor bars (3) embedded at the edge of the lower bearing platform (10). A spherical hinge (11) is arranged at the center position of the lower bearing platform (10). The center of the top of the spherical hinge (11) is fixedly provided with an active pressure jack (4). The top of the active pressure jack (4) is connected to the center of the bottom of the cross-shaped reaction frame (1) through a fixed hinge support (5). Four embedded pin seats (6) are respectively embedded at the top edge of the spherical hinge (11). The top of the embedded pin seat (6) is connected to a tension-compression dual-action jack (7). The top of the tension-compression dual-action jack (7) is connected to a movable pin hinge (8). The top of the movable pin hinge (8) is buckled at the bottom of the reaction arm (1-1) of the cross-shaped reaction frame (1). Four displacement gauges (9) are installed around the spherical hinge (11) on the top of the lower bearing platform (10). The connection lines of the opposite two displacement gauges (9) and the connection lines of the opposite two embedded pin seats (6) are respectively parallel to the straight line where one of the reaction arms (1-1) of the cross-shaped reaction frame (1) is located. The active pressure jack (4), the tension-compression dual-action jack (7) and the displacement gauge (9) are respectively connected to the control component.

2. The experimental device for the friction coefficient after installation of the swing bridge spherical hinge according to claim 1, characterized in that: The cross-shaped reaction frame (1) is composed of four reaction arms (1-1) arranged in a cross to form a cross-shaped box structure. Chute grooves are respectively opened on the bottom plates of the four reaction arms (1-1). The movable pin hinge (8) can be movably buckled in the chute grooves.

3. The experimental device for the friction coefficient after installation of the swing bridge hinge according to claim 2, wherein: The movable pin hinge (8) has an I-shaped cross-section. The movable pin hinge (8) includes a first movable pin hinge (8-1), a second movable pin hinge (8-2), a third movable pin hinge (8-3) and a fourth movable pin hinge (8-4).

4. The experimental device for the friction coefficient after installation of a rotating bridge spherical hinge according to claim 3, characterized in that: The chute grooves include a first chute groove (1-1-1), a second chute groove (1-1-2), a third chute groove (1-1-3) and a fourth chute groove (1-1-4). The tops of the first movable pin hinge (8-1), the second movable pin hinge (8-2), the third movable pin hinge (8-3) and the fourth movable pin hinge (8-4) can be respectively movably buckled in the first chute groove (1-1-1), the second chute groove (1-1-2), the third chute groove (1-1-3) and the fourth chute groove (1-1-4).

5. The experimental device for the friction coefficient after installation of the swing bridge hinge according to claim 2, characterized in that: The support steel cylinder (2) includes a first support steel cylinder (2-1), a second support steel cylinder (2-2), a third support steel cylinder (2-3), and a fourth support steel cylinder (2-4). The embedded anchor bars (3) include a first embedded anchor bar (3-1), a second embedded anchor bar (3-2), a third embedded anchor bar (3-3), and a fourth embedded anchor bar (3-4). The embedded pin seats (6) include a first embedded pin seat (6-1), a second embedded pin seat (6-2), a third embedded pin seat (6-3), and a fourth embedded pin seat (6-4). The displacement gauges (9) include a first displacement gauge (9-1), a second displacement gauge (9-2), a third displacement gauge (9-3), and a fourth displacement gauge (9-4). The first embedded anchor bar (3-1) and the second embedded anchor bar (3-2) are coaxially connected to the first support steel cylinder (2-1) and the second support steel cylinder (2-2) respectively. The line connecting the first embedded anchor bar (3-1) and the second embedded anchor bar (3-2) is parallel to the line connecting the first embedded pin seat (6-1) and the second embedded pin seat (6-2). The line connecting the first embedded pin seat (6-1) and the second embedded pin seat (6-2) is parallel to the line connecting the first displacement gauge (9-1) and the second displacement gauge (9-2). The third embedded anchor bar (3-3) and the fourth embedded anchor bar (3-4) are coaxially connected to the third support steel cylinder (2-3) and the fourth support steel cylinder (2-4) respectively. The line connecting the third embedded anchor bar (3-3) and the fourth embedded anchor bar (3-4) is parallel to the line connecting the third embedded pin seat (6-3) and the fourth embedded pin seat (6-4). The line connecting the third embedded pin seat (6-3) and the fourth embedded pin seat (6-4) is parallel to the line connecting the third displacement gauge (9-3) and the fourth displacement gauge (9-4).

6. The experimental device for the friction coefficient after installation of a rotating bridge spherical hinge according to claim 5, characterized in that: The first embedded pin seat (6-1), the second embedded pin seat (6-2), the third embedded pin seat (6-3), and the fourth embedded pin seat (6-4) are arranged orthogonally at a position 3 / 4 of the radius from the center of the plane of the spherical hinge (11).

7. An experimental device for the friction coefficient after installation of a rotating bridge spherical hinge according to any one of claims 1 to 6, characterized in that: The installation method of the experimental device includes the following steps: Step 1: After the steel bars of the lower bearing platform (10) are tied, four embedded anchor bars (3) are embedded in the lower bearing platform (10) at the positions of the cable passing holes of the corresponding cruciform reaction frame (1). Step 2: Four embedded pin seats (6) are installed corresponding to the edge of the spherical hinge (11), and then the concrete of the lower bearing platform (10) and the spherical hinge (11) is poured. Step 3: After the concrete reaches the strength, four support steel cylinders (2) and the cruciform reaction frame (1) are installed in sequence, and the cruciform reaction frame (1) is locked by the four embedded anchor bars (3). Step 4: An active pressure jack (4) is installed at the center position of the spherical hinge (11), and the bottom center of the cruciform reaction frame (1) is connected through a fixed hinge support (5). Four tension and compression double-acting jacks (7) are installed at the positions of the four embedded pin seats (6). The lower end of the tension and compression double-acting jack (7) is pin-connected to the embedded pin seat (6), and the upper end of the tension and compression double-acting jack (7) is pin-connected to the movable pin hinge (8). The top of the movable pin hinge (8) is buckled to the bottom of the reaction arm (1-1) of the cruciform reaction frame (1). Step 5: Install four displacement gauges (9) around the spherical hinge (11).

8. An experimental method for the friction coefficient after the installation of a rotating body bridge hinge, characterized in that, The implementation of an experimental device for the friction coefficient after the installation of a rotating body bridge spherical hinge according to any one of claims 1 to 6 includes the following steps: Step 1: Select two opposite tension-compression double-acting jacks (7) as the experimental axis, and apply pressure with the active pressure jack (4). N Apply equal pressure to the other two tension-compression double-acting jacks (7) perpendicular to the experimental axis. F ; Step 2: Apply a downward pressure to one of the tension-compression double-acting jacks (7) of the experimental shaft, and apply an upward pulling force to the other tension-compression double-acting jack (7). The force values are equal and the directions are opposite. Increase the pressure value and the pulling force value step by step at 1 kN, synchronously record the displacement values of the corresponding displacement gauges (9), and plot the force-displacement curve; after the inflection point appears on the force-displacement curve, record the pressure value F 1 and the pulling force value F 2, and the first group of experiments is completed; Step 3: Apply forces in the opposite direction to the two tension-compression double-acting jacks (7) of the experimental shaft until an inflection point appears again in the force-displacement curve, and record F 1’ F 2’, and the second group of experiments is completed; Step 4: Select the other two tension-compression double-acting jacks (7) as the new experimental axes, and the corresponding displacement gauges (9) measure the displacement values. Complete the third and fourth groups of experiments according to Steps 2 and 3 to obtain F 3、 F 4、 F 3’、 F 4’; Step 5: Calculate the friction coefficient of the spherical hinge based on the pressure value and the tensile force value obtained in Steps 2 to 4.

9. The experimental method for the friction coefficient after the installation of a rotating bridge spherical hinge according to claim 8, characterized in that, The specific content of Step 5 is as follows: Assume that the self-weight of the upper part of the spherical hinge (11) is G , the spherical radius of the spherical hinge (11) is R , the plane radius is r , and the distance from the center of the spherical hinge (11) to the centers of the two opposite tension-compression double-acting jacks (7) is L 1. L 2. For the first set of experiments, calculate the friction coefficient: Semi-apex angle of spherical crown of friction surface: ; Experimental maximum frictional torque: ; Vertical total load on the friction surface: ; Coefficient of friction: ; The friction coefficients are calculated in groups to obtain 4 groups μ 1、 μ 2、 μ 3、 μ 4; Ball joint friction coefficient: .

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