Counter-force self-balancing full-scale bending test platform for simply supported beam

Abstract

The utility model discloses a counter-force self-balancing full-scale bending test platform for a simply supported beam, which relates to the technical field of bridge engineering tests and specifically comprises a ground beam base, a ground beam, a test beam, a middle bearing component, a jack, a counter-force component, a concrete cast-in-place reinforcing layer and the like. The jack applies load downwards to the test beam through the self-balancing test platform, so that the stress test of the test beam is completed, the test mode is simple in operation, high in safety performance and reliable in test data, the test progress is accelerated, and meanwhile, the test fund is saved.

Description

Technical Field

[0001] The utility model belongs to the technical field of bridge engineering tests, and particularly relates to a reaction force self-balancing full-scale bending test platform for a simply supported beam. Background Art

[0002] For a new process or new structural system, in order to obtain real data, a model that is exactly the same as the actual one is generally used to carry out various working condition tests. This test model is a full-scale model, and this test is a full-scale test. The full-scale test of a simply supported beam structure is the test method that can most truly reflect the structural bearing capacity, deformation, crack resistance and other stress characteristics. At present, the stress performance destructive test of the full-scale hollow slab after reinforcement is generally carried out outdoors, and the loading methods of the test generally include the ordinary weight block pressure method and the column foundation reaction device method.

[0003] The common weight pressing method refers to placing heavy objects such as concrete blocks on the top surface of the full-scale hollow slab, and realizing step-by-step loading by continuously piling up the heavy objects. Since the bearing capacity of the full-scale beam is generally high, it is often necessary to apply nearly 100 tons of weight to complete the destructive test, which causes the heavy objects to be stacked very high. When the test beam is loaded to the point of destruction, it will produce sudden deformation, which is likely to cause the heavy objects to collapse, which is very dangerous. In addition, the method of adding heavy objects also has problems such as heavy hoisting weight, high hoisting difficulty, uneven test load, and low accuracy.

[0004] The column foundation reaction device is generally composed of double columns, upper beams, jacks, column foundations and other parts. The test beam is placed between the double columns and under the upper beam, and the jack is placed on the top of the test beam and under the upper beam. The action end of the jack is abutted against the lower end face of the upper beam. The column foundation is set on both sides of the test beam. The upper beam is erected on the column foundation and fixedly connected to the column foundation by a tie rod. The jack relies on the reaction of the upper beam to apply load to the test beam downward to complete the test of the test beam. Among them, the column foundation can be set by gravity or pile foundation. For full-scale tests, the foundation is generally large, requiring large-scale excavation or drilling by a drilling rig, which is complex and expensive to construct.

[0005] For outdoor tests, the investment and construction of the test platform is a one-time investment, and the probability of secondary use is very low. Therefore, developing a reasonable, reliable and economical full-scale bending test platform is the key to saving money in the research project. Utility Model Content

[0006] The purpose of the utility model is to provide a reaction force self-balancing full-scale bending test platform for simply supported beams. Compared with the traditional common weight block pressure test and column foundation reaction force device test, the test platform has simple test operation, high safety performance, cost saving and reliable test data. The specific technical solution is as follows:

[0007] A reaction force self-balancing full-scale bending test platform for a simply supported beam, comprising:

[0008] There are two ground beam foundations;

[0009] The ground beam, whose opposite ends are respectively erected on the two ground beam bases, is made of abandoned old beams, and the top surface of the abandoned old beam is set as the bottom surface and abuts against the upper surface of the ground beam base;

[0010] A middle bearing assembly, which is respectively arranged on opposite ends of the ground beam;

[0011] A test beam, whose opposite ends are mounted on the middle bearing assembly, and the middle bearing assembly is located between the ground beam and the test beam;

[0012] a jack, which is arranged on the test beam;

[0013] A reaction force assembly includes a reaction force beam and a pull rod, wherein the reaction force beam includes an upper reaction force beam and a ground reaction force beam, wherein the upper reaction force beam is arranged above the test beam, and the jack acts on the lower surface of the upper reaction force beam, and the ground reaction force beam is arranged below the ground beam, and the opposite ends of the upper reaction force beam and the opposite ends of the ground reaction force beam are connected by the pull rod. Under the action of the jack, the upper reaction force beam is slowly lifted up, and the ground reaction force beam is pulled by the pull rod to abut against the lower surface of the ground beam, and the ground beam begins to be subjected to force, which constrains the upper reaction force beam to be lifted upward, thereby providing a self-balancing reaction force for the jack, so that the jack applies a downward force to load the test beam.

[0014] Preferably, the test beam is an abandoned old beam.

[0015] Preferably, a plurality of the ground beams are arranged side by side to form a test platform.

[0016] Preferably, a cast-in-place concrete reinforcement layer is commonly provided on the top surfaces of the plurality of ground beams.

[0017] Preferably, the middle bearing assembly includes a cap beam and a rubber bearing, the cap beams are respectively provided on the top surfaces of the opposite ends of the ground beam, the rubber bearings are installed on the cap beams, and the test beam is supported on the rubber bearings.

[0018] Preferably, the ground reaction beam is installed in a limiting groove, and the ground reaction beam is limited by the limiting groove.

[0019] Preferably, the ground reaction beam comprises three I-beams, and the top surfaces and bottom surfaces of the three I-beams are respectively welded by welding rods to form the three I-beams into a whole.

[0020] Preferably, the upper reaction beam comprises three I-beams, and the top surfaces and bottom surfaces of the three I-beams are respectively welded by welding rods to form the three I-beams into a whole.

[0021] Preferably, the ground beam base portion is pre-buried under the ground.

[0022] Compared with the existing technology, the utility model has the following beneficial effects:

[0023] The utility model provides a reaction force self-balancing full-scale bending test platform for simply supported beams. The test platform is built by using abandoned old beams (blank plates). The jack uses the self-balancing test platform to apply a load downward to the test beam, thereby completing the force test of the test beam. The test method is simple to operate, has high safety performance, and reliable test data, which speeds up the progress of the test and saves test funds. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0025] Figure 1 It is a three-dimensional structural schematic diagram of the bending test platform of the utility model.

[0026] Figure 2 It is a front view of the bending test platform of the utility model.

[0027] Description of main reference numerals:

[0028] 1-ground beam base, 2-ground beam, 3-cap beam, 4-test beam, 5-reaction beam, 51-upper reaction beam, 52-ground reaction beam, 6-pull rod, 7-jack, 8-cast-in-place concrete reinforcement layer, 9-limiting groove. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0030] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "top", "bottom", "top surface", "bottom surface", "inside", "outside", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0031] In the description of the present utility model, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If the terms "first", "second", "third" are described, they are only used for the purpose of description and distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The following is a description of the embodiments of the present invention based on its overall structure.

[0033] Example

[0034] like Figure 1 to Figure 2 As shown, a reaction force self-balancing full-scale bending test platform for a simply supported beam specifically comprises: a ground beam base 1, a ground beam 2, a test beam 4, a middle bearing component, a jack 7, a reaction force component and a cast-in-place concrete reinforcement layer 8, etc.

[0035] The ground beam 2 is supported on the ground beam base 1, and the ground beam base 1 is pre-buried in the soil with a portion appropriately exposed.

[0036] The test platform is generally formed by 2-3 pieces of the ground beams 2 arranged in parallel. Furthermore, the ground beams 2 are selected from abandoned old beams, and the original top surface of the abandoned old beams is set as the bottom surface of the test platform, that is, the abandoned old beams are turned over for use.

[0037] A layer of cast-in-place concrete reinforcement layer 8 is provided on the top surface of the ground beam 2, and the cast-in-place concrete reinforcement layer 8 is combined with the ground beam 2 to form a coordinated force-bearing whole, which can further improve the bearing capacity of the ground beam 2. The cast-in-place concrete reinforcement layer 8 is poured on multiple parallel ground beams 2 to fix the multiple parallel ground beams 2 into a whole, thereby ensuring the strength of the ground beam 2 and increasing its overall bearing capacity.

[0038] The ground beam 2 is provided with a middle bearing assembly, which includes a cap beam 3 and a rubber bearing. After the construction of the cast-in-place concrete reinforcement layer 8 is completed, the cap beam 3 is set at both ends of the ground beam 2, wherein the width of the cap beam 3 is generally 50cm-100cm and the height is about 100cm, and the height is mainly to leave a test space.

[0039] The cap beam 3 is provided with a rubber support, the test beam 4 is supported on the cap beam 3 and transmits force through the rubber support, and the jack 7 is provided on the top surface of the test beam 4. During implementation, the test beam 4 is supported on the cap beam 3 located at both ends of the ground beam 2, and at this time, the test beam 4, the cap beam 3 and the ground beam 2 directly leave a test space.

[0040] Furthermore, the reaction force assembly includes a reaction force beam 5 and a pull rod 6, and the reaction force beam 5 includes an upper reaction force beam 51 and a ground reaction force beam 52, and the upper reaction force beam 51 is located above the ground reaction force beam 52, and the two ends are connected by the pull rod 6. In this preferred embodiment, the four-point loading method is taken as an example, and two reaction force beams 5 are set on a test platform, which include two upper reaction force beams 51 and two ground reaction force beams 52.

[0041] The upper reaction beam 51 is arranged above the test beam 4, the jack 7 acts on the lower surface of the upper reaction beam 51, and the ground reaction beam 52 is arranged below the ground beam 2. In this test, the ground reaction beam 52 is arranged slightly below the ground, and the ground beam 2 is hoisted after the ground reaction beam 52 is pre-placed. During the test, the ground reaction beam 52 does not need to be disassembled, and the ground reaction beam 52 is limited by the limit groove 9.

[0042] The opposite ends of the upper reaction beam 51 and the opposite ends of the ground reaction beam 52 are connected by the pull rod 6. When the jack 7 is lifted, the upper reaction beam 51 is slowly lifted up, and the ground reaction beam 52 is pulled by the pull rod 6 to abut against the lower surface of the ground beam 2. The ground beam 2 begins to be subjected to force, which restricts the upper reaction beam 51 to be lifted upward, providing a self-balancing reaction force for the jack 7, so that the jack 7 applies a downward force to load the test beam 4.

[0043] In the present invention, the ground reaction beam 52 and the upper reaction beam 51 are both formed by welding I-beams.

[0044] The working principle of a reaction force self-balancing full-scale bending test platform for simply supported beams is as follows:

[0045] The platform is a self-balancing loading platform. After the jack 7 works, the upper reaction beam 51 is slowly lifted up. Through the pulling of the pull rod 6, the ground reaction beam 52 is slowly pulled up until it reaches the bottom surface of the ground beam 2. The platform system begins to self-balance the force. Since the stiffness and bending bearing capacity of the ground beam 2 are much greater than those of the test beam 4, the upward bending deformation of the ground beam 2 can be ignored, and a self-balancing reaction force can be provided for the upper reaction beam 51. Therefore, the jack 7 can apply a downward force to the test beam 4 through the upper reaction beam 51 to load the test beam 4 to realize the test.

[0046] Specifically, taking a hollow slab with a span of 16m as an example, a full-scale bending test platform is designed.

[0047] The ground beam foundation 1 is only used to bear the deadweight of the test platform and the test beam 4. There is no additional test load during the loading process. Therefore, the ground beam foundation 1 does not need to be too large. The cross-sectional width of the ground beam foundation 1 is 0.9m, the thickness is 0.5m, and the length is consistent with the width of the ground beam 2. No reinforcement is required.

[0048] The ground beam 2 is two pieces of abandoned old beams identical to the test beam 4 (disassembled from the old bridge, just flip the top and bottom surfaces). By using the abandoned old beams, the test cost can be greatly saved and the test progress can be accelerated. The thickness of the cast-in-place concrete reinforcement layer 8 is 10 cm, and C40 concrete is used. The longitudinal reinforcement is set in a way that HRB400 grade steel bars with a diameter of 25 mm are set at intervals of 10 cm. Shear bars are implanted in a plum blossom shape at intervals of 0.4 m on the top surface of the abandoned old beam, so that the cast-in-place concrete reinforcement layer 8 and the ground beam 2 work together and improve the stiffness and bearing capacity of the ground beam 2.

[0049] The cap beam 3 is 0.6m wide and 1.0m high, leaving sufficient operation and observation space for test personnel.

[0050] After reinforcement, the test beam 4 is hoisted and placed on the cap beam 3, and loading begins for a destructive test. The measuring instruments for the displacement of the test beam 4 need to be independent of the self-balancing system.

[0051] The ground reaction beam 52 is subjected to the uniform load of the ground beam 2, and the upper reaction beam 51 is subjected to the concentrated load of the jack 7. The forces on the two are different, and the upper reaction beam 51 is subjected to a greater force. One ground reaction beam 52 is composed of three pieces of I-beams of type 20b, and steel bars are welded on the top and bottom surfaces to form a whole. One ground reaction beam 51 is composed of three pieces of I-beams of type 36a, and steel bars are welded on the top and bottom surfaces to form a whole.

[0052] The pull rod 6 is PSB930 type finely rolled threaded steel bar with a diameter of 28 mm.

[0053] The threaded steel matching nut can be connected to the ground reaction beam 51 and the upper reaction beam 52 after being tightened at the beam end of the pull rod 6.

[0054] After the test is finished, the upper reaction beam 51 and the test beam 4 can be disassembled by unscrewing the nut. After the test beam 4 is replaced, the force test of the next test beam 4 can be carried out.

[0055] The utility model provides a reaction force self-balancing full-scale bending test platform for simply supported beams. The test platform is built by using abandoned old beams (blank plates). The jack uses the self-balancing test platform to apply a load downward to the test beam, thereby completing the force test of the test beam. The test method is simple to operate, has high safety performance, and reliable test data, which speeds up the progress of the test and saves test funds.

[0056] The foregoing descriptions of specific exemplary embodiments of the present invention are for the purpose of explanation and illustration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is obvious that many changes and variations can be made based on the above teachings. Although an embodiment of the present invention has been shown and described, this specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. The specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can make modifications, substitutions, variations and various selections and changes to the embodiments without creative contribution as needed after reading this specification without departing from the principles and purpose of the present invention, but they are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A self-balancing full-scale bending test platform for simply supported beams, characterized in that: include: Two ground beam bases (1); The ground beam (2) has two opposite ends respectively mounted on the two ground beam bases (1); the ground beam (2) is made of discarded old beams, and the top surface of the discarded old beam is set as the bottom surface and abuts against the upper surface of the ground beam base (1); A middle bearing assembly, which is respectively arranged on two opposite ends of the ground beam (2); A test beam (4), whose opposite ends are mounted on the middle bearing assembly, and the middle bearing assembly is located between the ground beam (2) and the test beam (4); A jack (7) disposed on the test beam (4); A reaction force assembly comprises a reaction force beam (5) and a pull rod (6), wherein the reaction force beam (5) comprises an upper reaction force beam (51) and a ground reaction force beam (52), wherein the upper reaction force beam (51) is arranged above the test beam (4), the jack (7) acts on the lower surface of the upper reaction force beam (51), the ground reaction force beam (52) is arranged below the ground beam (2), and the opposite ends of the upper reaction force beam (51) are in contact with the ground reaction force beam (52). The two opposite ends of the ground beam (2) are connected by the pull rod (6). Under the action of the jack (7), the upper reaction beam (51) is slowly lifted up, and the ground reaction beam (52) is pulled by the pull rod (6) to abut against the lower surface of the ground beam (2). The ground beam (2) begins to be subjected to force, which constrains the upper reaction beam (51) to lift upward, providing a self-balancing reaction force for the jack (7), so that the jack (7) applies a downward force to load the test beam (4).

2. A reaction force self-balancing full-scale bending test platform for simply supported beams according to claim 1, characterized in that: The test beam (4) is an abandoned old beam.

3. The reaction force self-balancing full-scale bending test platform of a simply supported beam according to claim 1, characterized in that: A test platform is formed by arranging a plurality of ground beams (2) side by side.

4. The reaction force self-balancing full-scale bending test platform of a simply supported beam according to claim 1, characterized in that: A layer of cast-in-place concrete reinforcement layer (8) is commonly provided on the top surfaces of the plurality of ground beams (2).

5. The reaction force self-balancing full-scale bending test platform of a simply supported beam according to claim 1, characterized in that: The middle bearing assembly comprises a cap beam (3) and a rubber support, the cap beams (3) are respectively provided on the top surfaces of the two opposite ends of the ground beam (2), the rubber support is mounted on the cap beam (3), and the test beam (4) is supported on the rubber support.

6. The reaction force self-balancing full-scale bending test platform of a simply supported beam according to claim 1, characterized in that: The ground reaction force cross beam (52) is installed in the limiting groove (9), and the ground reaction force cross beam (52) is limited by the limiting groove (9).

7. The reaction force self-balancing full-scale bending test platform of a simply supported beam according to claim 1, characterized in that: The ground reaction beam (52) comprises three I-beams, the top surfaces and bottom surfaces of the three I-beams being welded by welding rods respectively so that the three I-beams form a whole.

8. The reaction force self-balancing full-scale bending test platform of a simply supported beam according to claim 1, characterized in that: The upper reaction force cross beam (51) comprises three I-beams, and the top surfaces and bottom surfaces of the three I-beams are respectively welded by welding rods so that the three I-beams form a whole.

9. The reaction force self-balancing full-scale bending test platform of a simply supported beam according to claim 1, characterized in that: The ground beam base (1) is partially pre-buried under the ground.

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