Asymmetric U-shaped steel and beam falling prevention device

Abstract

The utility model discloses asymmetric U-shaped steel and a beam falling prevention device. The utility model discloses a U-shaped connecting plate which comprises an upper plate and a lower plate which are arranged in parallel, the upper plate and the lower plate are connected through a connecting plate to form a U-shaped structure, the opening direction of the U-shaped structure is the first direction, and the width of the upper plate in the second direction perpendicular to the first direction is larger than that of the lower plate in the second direction perpendicular to the first direction. The U-shaped steel has the characteristic that the upper part and the lower part of the U-shaped steel are not equal in width, so that the arrangement of a daily working condition activity structure is facilitated, the size of the lower part is small, the influence on a lower support plate and a padstone is reduced, the requirement of the support on the size of the U-shaped steel is better met, and the difficulty in mounting the support possibly caused by overlarge size of the lower support plate of the support is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of bridge engineering, and particularly relates to an asymmetric U-shaped steel and a falling prevention beam device. Background Technique

[0002] The falling prevention beam device is used for preventing the upper structure of a bridge from falling caused by an earthquake and mitigating the impact damage to other falling prevention beam devices during an earthquake in a bridge engineering structure. When the support bolts are sheared and lose the horizontal bearing capacity, the horizontal force of the upper structure is transmitted to the lower structure through the falling prevention beam device to achieve the engineering application purpose.

[0003] Due to its good elastoplastic deformation ability, ultimate tensile ability and economy, U-shaped steel has been applied in the construction of high-speed railway bridges. At present, it is widely used to combine U-shaped steel with connecting parts to form an independent falling prevention beam device and apply it to bridges. This U-shaped falling prevention beam device takes into account the movement amount in the longitudinal direction of the bridge during design and also considers the matching with the bridge support in terms of height. Therefore, it has good performance in device installation, adaptability to the movement amount in the longitudinal direction under normal working conditions, and the ability to prevent the beam from falling under earthquake conditions. The U-shaped steel used in this product has the same width at the upper and lower parts. Since the longitudinal movement amount of the bridge is considered in the upper part of the U-shaped steel, the width dimension of the U-shaped steel is relatively large. This independent falling prevention beam device requires an independent connecting device, and the material utilization rate of the connecting parts is relatively low, and the economy is slightly poor. Secondly, during installation, the workload of installing this device needs to be considered independently. In addition, since the movement amount under normal working conditions needs to be considered in the upper part, it is relatively wide, and the lower part is designed to have the same width as the upper part, so the size is also relatively large, which also has a greater impact on the size of the installation cushion stone.

[0004] If the U-shaped steel is integrated with the support to enable the support to have the function of preventing the beam from falling, the workload of independently installing the falling prevention beam device can be saved, and the U-shaped steel can also share certain connecting parts with the support, improving the material utilization rate and also improving the economy to a certain extent. However, the U-shaped steel designed with this design idea has a relatively large lower part size, and the lower part size of the U-shaped steel will directly affect the lower part size of the support, which will lead to a relatively large lower plate size of the support and there are certain problems with the installation space. Moreover, due to the increase in the lower support plate of the support, the manufacturing cost of the support will also increase. Therefore, the U-shaped steel designed with this design idea is not suitable for directly being used on the support.

[0005] Patent CN 116956448 A discloses the idea of determining the size of U-shaped steel only from the perspective of mechanical calculation, gives a recommended calculation formula for the anti-falling beam force-displacement, and verifies the accuracy of the recommended formula through experiments. However, the U-shaped steel structure disclosed in this patent has the same width at the top and bottom, which is more suitable for being made into an anti-falling beam product independently, lacking consideration of the actual conditions for installation on the bearing, such as the adaptability of the U-shaped steel to the longitudinal movement amount under daily working conditions, and also not considering the problems of the matching between the size of the U-shaped steel and the size of the bearing body, and the influence of the size of the U-shaped steel on the size of the lower bearing plate of the bearing. Summary of the Invention

[0006] The purpose of the present invention is to solve the deficiencies existing in the above-mentioned background technology, and provide an asymmetric U-shaped steel and an anti-falling beam device with a simple structure, so as to consider adapting to the longitudinal movement amount under daily working conditions and the anti-falling beam ability under seismic conditions, and minimize the influence on the plane size of the lower bearing plate of the bearing or the lower connecting parts of the anti-falling beam device, and further reduce the influence on the size of concrete structures such as cushion stones.

[0007] The technical solution adopted by the present invention is: an asymmetric U-shaped steel, including an upper plate and a lower plate arranged in parallel, the upper plate and the lower plate are connected by a connecting plate to form a U-shaped structure, the opening direction of the U-shaped structure is the first direction, and the width of the upper plate along the second direction perpendicular to the first direction is greater than the width of the lower plate along the second direction perpendicular to the first direction.

[0008] Furthermore, the connecting plate is an arc-shaped plate with a gradually changing width, and the sides at both ends of the connecting plate where the width changes are smoothly transitioned.

[0009] Furthermore, the connection positions of the two ends of the connecting plate with the upper plate and the lower plate are both smoothly transitioned.

[0010] Furthermore, the relationship between the width of the lower plate, the thickness of the U-shaped steel plate, the total height of the U-shaped steel, the displacement of the anti-falling beam and the anti-falling beam force is

[0011] F s = 0.26×B 1.29 - 2×H 0.9 + 0.14×T 2.15 + 0.5×S 0.6

[0012] Wherein, F S is the anti-falling beam force, B is the width of the lower plate, H is the total height of the U-shaped steel, T is the thickness of the U-shaped steel plate, and S is the displacement of the anti-falling beam.

[0013] Furthermore, the width of the upper plate is 100 mm to 500 mm.

[0014] Further, the upper plate, the lower plate, and the connecting plate have the same thickness, and the thickness of the upper plate is 10 mm to 40 mm.

[0015] Further, the vertical height between the top surface of the upper plate and the bottom surface of the lower plate is 100 mm to 300 mm.

[0016] Further, a plurality of first bolt holes are provided on the upper plate, and the first bolt holes are waist-shaped holes.

[0017] Still further, a plurality of second bolt holes are provided on the lower plate, and the second bolt holes are round holes.

[0018] A beam fall prevention device includes the asymmetric U-shaped steel as described above. The upper plate of the asymmetric U-shaped steel is used to connect the bottom of the beam body, and the lower plate of the asymmetric U-shaped steel is connected to the top of the bridge pier.

[0019] The beneficial effects of the present utility model are as follows:

[0020] The asymmetric U-shaped steel of the present utility model has the characteristic of unequal width up and down, which is beneficial to setting the activity amount structure under daily working conditions. The lower size is small, reducing the influence on the lower bearing plate and the cushion stone, and better conforming to the size requirements of the bearing for the U-shaped steel, reducing the possible difficulty in installing the bearing caused by the too large size of the lower bearing plate of the bearing.

[0021] The present utility model considers the activity amount of the U-shaped steel in the longitudinal direction of the bridge under daily working conditions and the beam fall prevention ability under seismic conditions. At the same time, through the special design of the U-shaped steel structure, the influence on the plane size of the lower bearing plate of the bearing or the lower connecting member of the beam fall prevention device can be minimized, and further the influence on the size of the cushion stone and other concrete structures can be reduced.

[0022] The width of the lower plate of the U-shaped steel of the present utility model can be obtained based on the beam fall prevention force calculation formula. This method is simpler and easier to be mastered and applied by technicians in the industry. Moreover, the beam fall prevention displacement parameter is introduced into the formula, and the calculation result is more reasonable.

[0023] The parameter design of the U-shaped steel of the present utility model fully considers the parameter performance such as the beam fall prevention ability, as well as the structural factors such as the bolt installation space, the total height of the bearing body, the size of the lower bearing plate, the influence of the cushion stone size, and the installation space. The designed U-shaped steel is more suitable for use on the bearing. When separately made into a beam fall prevention device, due to the smaller size of the lower connecting member, the influence on the size of the cushion stone is also smaller. Description of the Drawings

[0024] Figure 1 It is a structural schematic diagram of the present utility model.

[0025] Figure 2 It is a side view of the present utility model.

[0026] Figure 3 Schematic diagram of the dimensions, bolt holes and first-order counterbores of the upper plate of the present utility model.

[0027] Figure 4 Schematic diagram of the dimensions, bolt holes and first-order counterbores of the lower plate of the present utility model.

[0028] Figure 5 Schematic diagram of the second-order counterbore of the lower plate of the present utility model.

[0029] In the figure, 1 - upper plate; 2 - lower plate; 3 - connecting plate; 4 - side; 5 - connection point; 6 - first bolt hole; 7 - second bolt hole. Detailed implementation mode

[0030] The following further explains the detailed implementation mode of the present utility model with reference to the attached drawings. It should be noted here that the description of these implementation modes is used to help understand the present utility model, but does not constitute a limitation to the present utility model. In addition, the technical features involved in the various implementation modes of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0031] As Figures 1-5 shown, the present utility model provides an asymmetric U-shaped steel for bridges, including an upper plate 1 and a lower plate 2 arranged in parallel. The upper plate 1 and the lower plate 2 are integrally connected by a connecting plate 3 to form a U-shaped structure. The opening direction of the U-shaped structure (i.e., the direction perpendicular to the cross-section of the upper plate, the lower plate and the connecting plate at the same time) is the first direction (i.e., the width direction parallel to the side of the upper plate in the figure), and the direction perpendicular to the first direction is the second direction (i.e., the length direction in the figure). The width B1 of the upper plate 1 along the second direction is greater than the width B of the lower plate 2 along the second direction, that is, the U-shaped steel is an upper and lower asymmetric structure with the central horizontal plane between the upper plate 1 and the lower plate 2 as the reference. This special structure takes into account the movement amount of the U-shaped steel in the longitudinal direction of the bridge under normal working conditions and the anti-falling beam ability under seismic conditions. At the same time, through the special design of the U-shaped steel structure, the influence on the plane size of the lower support plate of the support or the lower connecting piece of the anti-falling beam device can be minimized, and then the influence on the size of the concrete structure such as the bearing pad can be reduced.

[0032] During implementation and application, the U-shaped steel can be integrated with the bridge support to form an anti-falling beam acting on the bridge. At this time, the upper plate is connected to the upper support plate of the support, and the lower plate is connected to the lower support plate of the support or other structural members; the U-shaped steel can be used as an independent anti-falling beam product. At this time, the U-shaped steel is the U-shaped steel anti-falling beam. The upper plate is connected to the bottom of the beam body, and the lower plate with a smaller bottom width dimension is connected to the concrete structure such as the bearing pad or the top of the bridge pier, which can effectively reduce the size of the lower structure, improve the space utilization rate and reduce the cost.

[0033] As a preferred solution, the U-shaped steel has a left-right symmetric structure with respect to a vertical plane perpendicular to the centers of the upper plate, the lower plate, and the connecting plate, that is, the width of the lower plate is smaller than that of the upper plate, and at the same time, it is symmetrically arranged left and right with respect to the upper plate, forming a left-right symmetric structure. The lengths of the upper plate and the lower plate in the first direction can be the same, or can be designed differently according to actual installation requirements. On this basis, the connecting plate 3 is designed as a circular arc plate with a gradually changing width, and the sides 4 at the width-changing positions at both ends of the connecting plate 3 are all smoothly transitioned (that is, the starting point and the ending point of the gradually changing width are arc-transitioned), and the joints 5 between the ends of the connecting plate 3 and the upper plate 1 and the lower plate 2 are all smoothly transitioned (that is, the side surface of the U-shaped steel is tangent to the surface), so as to avoid the sudden change of stiffness and strength from affecting the mechanical properties of the U-shaped steel.

[0034] As a preferred solution, a plurality of first bolt holes 6 are provided on the upper plate 1, and the first bolt holes are waist-shaped holes arranged in the second direction. The waist-shaped holes can also be processed with a counterbore according to installation requirements; a plurality of circular second bolt holes 7 are provided on the lower plate 2, and the second bolt holes can be processed with a counterbore according to installation requirements. When processing the counterbore, the edge of the counterbore extends to the side surfaces of the upper plate and the lower plate.

[0035] As a preferred solution, in terms of dimension design, the total height of the U-shaped steel (that is, the vertical height H between the top surface of the upper plate and the bottom surface of the lower plate) is calculated from structural dimensions such as the bolt length and the height of the support body, and the preferred dimension is 100 mm to 300 mm. The plate thickness and the lower width are mainly calculated by mechanical strength and stiffness, and at the same time, the structural dimensions of the lower support plate of the support are considered for calculation. The plate thickness T is preferably 10 mm to 40 mm; the upper width (that is, the total width of the U-shaped steel) is calculated by combining the design movement with the determined lower dimensions, and is preferably 100 mm to 500 mm; this U-shaped steel is applicable to the anti-falling beam displacement of 10 mm to 100 mm and the daily working condition movement of 5 mm to 80 mm.

[0036] By setting Q355 steel plates with a thickness of 10 mm to 40 mm at different heights and widths, no less than 200 finite element calculation models are established and analyzed and calculated. The anti-falling beam forces of each model under ±10 mm, ±20 mm... ±100 mm can be analyzed, and a part of them are selected to make test pieces to verify the accuracy of the finite element calculation through tests. According to the characteristic dimensions of each model and the anti-falling beam force results obtained from the finite element analysis and calculation, through data analysis and using the incomplete induction method, the characteristic dimensions of each influencing factor can be raised to the power and then multiplied by the influence coefficient, and finally these values are accumulated to obtain the calculation formula (numerical calculation) of the lower plate width and the anti-falling beam force as follows

[0037] F s =0.26×B 1.29 -2×H 0.9+0.14×T 2.15 +0.5×S 0.6

[0038] Where: F S is the anti-falling beam force, B is the width of the lower plate, H is the total height of the U-shaped steel, T is the thickness of the U-shaped steel plate, and S is the anti-falling beam displacement

[0039] The present utility model also provides a design method for an asymmetric structure U-shaped steel for the above-mentioned bridge, comprising the following steps:

[0040] S1. Determine the bolt size of the U-shaped steel according to the anti-falling beam force.

[0041] S2. Calculate the dimensions such as the plate thickness, lower length, hole diameter, and bolt length of the U-shaped steel through strength calculation based on the bolt size and the material properties of the U-shaped steel.

[0042] S3. Calculate the height dimension of the U-shaped steel based on the bolt length, plate thickness, and the height of the support body.

[0043] S4. Calculate the key lower width dimension of the U-shaped steel according to the height, plate thickness, material properties, and required anti-falling beam displacement of the U-shaped steel. The anti-falling beam force calculation formula is:

[0044] F s = 0.26×B 1.29 - 2×H 0.9 + 0.14×T 2.15 + 0.5×S 0.6 .

[0045] S5. Calculate the upper width and upper length dimensions of the U-shaped steel according to the lower width, lower length, and daily working condition activity of the U-shaped steel.

[0046] S6. After obtaining the complete characteristic dimensions of the U-shaped steel, verify the requirements such as the installation space of the bolts again. If the requirements are not met, perform counterboring (i.e., machining a counterbore). The counterbore can be a first-order counterbore 7.1 and a second-order counterbore 7.2 according to the actual situation to complete the design of the U-shaped steel. The characteristics of the first-order counterbore are: the edge of the counterbore extends to the side of the U-shaped steel all the time; the characteristics of the second-order counterbore are: the edge of the counterbore also needs to extend to the side of the U-shaped steel, and the two-order counterbores are adjacent.

[0047] In the utility model, the upper width of the U-shaped steel is larger than the lower width. The manufacturing process of the U-shaped steel can adopt bending the steel plate into shape, and the unfolded characteristic dimensions can be deduced from the characteristic dimensions of the finished U-shaped steel obtained by calculation. For the simple supported beam bearing of a railway, it can be considered to set 2 completely identical U-shaped steels for each bearing. If so, when calculating, half of the designed anti-falling beam force can be taken into the calculation. 2 bolts are set for each U-shaped steel. Combining with the strength grade of the bolts, the nominal diameter of the bolts can be calculated. Adding 2 mm to the nominal diameter of the bolts gives the bolt hole diameter. The height of the U-shaped steel is determined according to the height of the bearing. Using the anti-falling beam force calculation formula disclosed in the utility model and combining with the relevant structural dimension requirements of the bolts, the lower width and the steel plate thickness dimension of the U-shaped steel can be calculated. When designing the upper dimensions, the same number of bolts as the lower part is also used for the upper part. When designing the upper bolt holes, the long slot hole scheme can be adopted to meet the requirements of the daily working condition activity. The width dimension of the long slot hole can be directly the same as that of the lower bolt hole, and the length can be taken as the width dimension plus 2 times the designed activity. The total width dimension of the upper steel plate is mainly determined according to the dimension of the long slot hole and the relevant structural requirements that the bolt connection needs to meet.

[0048] The utility model also provides an anti-falling beam device, which includes the asymmetric U-shaped steel designed as above. The upper plate of the asymmetric U-shaped steel is used to directly or indirectly connect the bottom of the beam body, and the lower plate of the asymmetric U-shaped steel is used to directly or indirectly connect the top of the bridge pier. Using the asymmetric U-shaped steel for the anti-falling beam can make the anti-falling beam force reach the design requirement and meet a certain shock absorption function.

[0049] The above is only the specific implementation manner of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the utility model should be covered within the protection scope of the utility model. The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

Claims

1. An asymmetric U-shaped steel, characterized in that: It includes an upper plate and a lower plate arranged in parallel. The upper plate and the lower plate are connected by a connecting plate to form a U-shaped structure. The opening direction of the U-shaped structure is the first direction. The width of the upper plate along the second direction perpendicular to the first direction is greater than the width of the lower plate along the second direction perpendicular to the first direction. A number of first bolt holes are provided on the upper plate, and the first bolt holes are waist-shaped holes. A number of second bolt holes are provided on the lower plate, and the second bolt holes are round holes.

2. The asymmetric U-shaped steel according to claim 1, characterized in that: The connecting plate is an arc-shaped plate with a gradually changing width, and the sides at the width-changing positions at both ends of the connecting plate are smoothly transitioned.

3. The asymmetric U-shaped steel according to claim 1, characterized in that: The connection positions of the end of the connecting plate with the upper plate and the lower plate are both smoothly transitioned.

4. The asymmetric U-shaped steel according to claim 1, wherein: The relationship formula between the width of the lower plate, the thickness of the U-shaped steel plate, the total height of the U-shaped steel, the displacement of the anti-falling beam and the anti-falling beam force is F s = 0.26 × B 1.29 - 2 × H 0.9 + 0.14 × T 2.15 + 0.5 × S 0.6 Among them, F S is the anti-falling beam force, B is the width of the lower plate, H is the total height of the U-shaped steel, T is the thickness of the U-shaped steel plate, and S is the anti-falling beam displacement.

5. The asymmetric U-shaped steel according to claim 1, wherein: The width of the upper plate is 100 mm to 500 mm.

6. The asymmetric U-shaped steel according to claim 1, characterized in that: The upper plate, the lower plate and the connecting plate have the same thickness, and the thickness of the upper plate is 10 mm to 40 mm.

7. The asymmetric U-shaped steel according to claim 1, wherein: The vertical height between the top surface of the upper plate and the bottom surface of the lower plate is 100 mm to 300 mm.

8. A beam anti-falling device, characterized in that: It includes the asymmetric U-shaped steel as described in claim 1. The upper plate of the asymmetric U-shaped steel is used to connect the bottom of the beam body, and the lower plate of the asymmetric U-shaped steel is used to connect the top of the bridge pier.

Images