An effectiveness test method for super-span floor support plate counter-pulling system

Abstract

The application provides a kind of super-span floor support plate counter-pulling system effectiveness test method, S1 builds test platform, set up non-pulling experimental group and non-pulling control group;S2 measures deflection on the test platform equivalent to load yellow sand;S3 deflection value and limit value comparison, if the deflection of each point of the pulling experimental group is less than the limit value, and the deflection of each point of the non-pulling control group exceeds the limit value, then determine that the counter-pulling system is effective. This method can quickly, accurately and at low cost verify the performance of the counter-pulling system, and provide reliable basis for the construction scheme.

Description

Technical Field

[0001] This invention belongs to the field of building structure testing and construction inspection technology, and relates to a method for testing the effectiveness of a large-span steel truss floor deck anti-tension support system. It is applicable to large-span steel structure projects where it is inconvenient to install supports under the floor deck and upper anti-tension supports are used. Background Technology

[0002] Currently, in steel structure construction, temporary supports are set up for large-span steel truss floor slabs before construction. The safety of the support system needs to be verified. Traditional in-situ load tests are costly, time-consuming, and have poor load control accuracy, making it difficult to simulate the most unfavorable simply supported conditions. Summary of the Invention

[0003] This invention employs equivalent material loading, providing a test method for the effectiveness of a super-span floor decking anti-tension system. This method enables rapid, accurate, and low-cost verification of the deformation performance of the support system and the floor decking, providing a reliable basis for construction plans.

[0004] A test method for the effectiveness of a super-span floor deck anti-tension system. S1. Set up the experimental platform and define the taut experimental group and the non-taut control group; S2 was loaded with equivalent yellow sand on the test platform and the deflection was measured. If the deflection value of S3 is compared with the limit value, and the deflection of each point in the taut experimental group is less than the limit value, while the deflection of each point in the non-taut control group exceeds the limit value, then the anti-tension system is deemed effective.

[0005] Furthermore, in the aforementioned method for testing the effectiveness of a super-span floor deck anti-tension system, the test platform in S1 includes: a simulated main beam, an I-beam main beam, an I-beam secondary beam, a floor deck, concrete supports, and formwork; The simulated structure's main beams are set on a flat ground, with one beam on each side. The floor decking is laid flat on the simulated main beam, with its length direction perpendicular to the simulated main beam; the concrete supports are set on the simulated main beam, along the length direction of the main beam; the I-beam main beam is set on the concrete supports, along the length direction of the floor decking; the I-beam secondary beam is set on the I-beam main beam and parallel to the simulated main beam; the line connecting the middle concrete supports on the simulated main beam serves as the boundary, with one side designated as the tensioned experimental group and the other side as the non-tensioned control group, and the floor decking and I-beam secondary beam of the tensioned experimental group are set as a counter-tension system; after the platform is completed, formwork is erected around the edge of the platform.

[0006] Preferably, in the above-mentioned method for testing the effectiveness of a super-span floor deck anti-tension system, the concrete supports in S1 are 300×300×250mm cube-shaped concrete supports, with 3 on each side, for a total of 6 supports.

[0007] Preferably, in the aforementioned method for testing the effectiveness of a super-span floor decking anti-tension system, the floor decking is fixed to the main beam of the simulated structure using studs, with its length direction perpendicular to the main beam of the simulated structure.

[0008] Preferably, in the aforementioned method for testing the effectiveness of a super-span floor deck anti-tension system, the anti-tension system uses angle steel and hooks to hold the chord reinforcement of the floor deck as anti-tension supports, and the hook spacing is set to two hooks spaced one apart.

[0009] Furthermore, in the aforementioned method for testing the effectiveness of a super-span floor decking anti-tension system, step S2 includes: The first load was a static load of sand; after the load stabilized, the deflection at mid-span of the main beam, secondary beam, anti-tension support, and floor deck was measured. The second sand pile load was applied, followed by dynamic load loading. After the load stabilized, the deflection at mid-span of the main beam, secondary beam, anti-tension support, and floor deck was measured. Preferably, in the aforementioned method for testing the effectiveness of a super-span floor deck anti-tension system, the static load height of the yellow sand in S2 is calculated using the equivalent simulated concrete self-weight of yellow sand.

[0010] Preferably, in the aforementioned method for testing the effectiveness of a super-span floor deck anti-tension system, the static load height of the yellow sand pile in S2 is 320mm.

[0011] Furthermore, in the aforementioned method for testing the effectiveness of a super-span floor decking anti-tension system, the deflection measurement points in S2 are arranged at the junction of the main and secondary beams, at the anti-tension support, and at the mid-span of the floor decking.

[0012] Furthermore, in the aforementioned test method for the effectiveness of a super-span floor decking anti-tension system, the limit value is taken as 1 / 250 of the calculated span based on the concealed working condition of the floor decking bottom surface.

[0013] The beneficial effects of this invention are: 1. Yellow sand is used to simulate concrete load, which is easy to obtain, low in cost, and ensures uniform loading. 2. Set up a control experiment to visually demonstrate the deformation reduction effect of the anti-tension system; 3. The test cycle is short and can be implemented on-site, providing direct data support for the plan, and the data directly guides the construction; 4. Designed according to the most unfavorable simply supported working condition, the test results are safe and reliable; 5. No lower support required, suitable for high-altitude, large-span, and no-lower-work-space conditions. Attached Figure Description

[0014] Figure 1 An experimental platform of the present invention; Detailed Implementation

[0015] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a more comprehensive explanation of the effectiveness testing method for a super-span floor decking anti-tension system proposed in this invention. The advantages and features of this invention will become clearer from the following description and claims. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of this invention.

[0016] Implementation method: This experiment was conducted on the anti-tension system of the floor decking of the Shanghai International Gymnastics Center, and the floor decking with a maximum span of 5482mm was selected as the test object.

[0017] S1 constructed an experimental platform and set up a taut experimental group and a non-taut control group. A 6.6m × 6m test platform was constructed based on the span of the floor decking. The test platform included a simulated main beam 1, an I-beam main beam 2, concrete supports 3, I-beam secondary beams 4, the floor decking, and formwork. Figure 1 As shown, Figure 1 This is an experimental platform of the present invention.

[0018] The simulated structure main beam 1 is made of HW400 steel and is set on a flat ground, with one beam on each side. The floor decking is laid flat on the simulated main beam 1, with its length direction perpendicular to the simulated main beam. A total of 10 deckings are laid and fixed with studs. The concrete supports 3 are set on the main beam 1 of the simulated structure, and are arranged along the length of the main beam 1, with 3 on each side; the concrete supports are 300×300×250mm concrete piers; the pier curing, stud welding and measuring point arrangement are completed before the test. The I-beam main beam 2 is set on the concrete support 3, along the floor decking laying direction, and is the main beam of the anti-tension system, using 25B I-beams; the I-beam secondary beam 4 is made of 18# I-beams, set on the I-beam main beam 2, and parallel to the simulated structural main beam 1, with two beams placed per span; the line connecting the middle concrete support on the left and right simulated structural main beams is set as the boundary, one side is the tension test group 6, and the other side is the non-tension control group 7. The floor decking and the I-beam secondary beam of the tension test group 6 are set as an anti-tension system, and the anti-tension supports 5 are arranged according to the actual project; after the platform is completed, the template is erected around the edge of the platform, and the test platform is completed.

[0019] The anti-tension support 5 uses angle steel and hooks to hold the chord reinforcement of the floor deck, with the hooks spaced two hooks apart and one hook spaced apart. This technology is existing technology, and the specific structure and connection method will not be described in detail here.

[0020] Since the floor decking in the actual project is supported by continuous beam spans, and the maximum span is set 0.5m longer than the actual span, and the tensile force is generated quickly after the concrete is poured, based on the above, when loading yellow sand, only the static load and dynamic load of the concrete are converted without adding a safety factor. Therefore, the formwork height is set to 500mm and reinforced to prevent yellow sand from scattering.

[0021] S2 was subjected to an equivalent load of yellow sand on the test platform, and the deflection was measured. On the floor deck, yellow sand was evenly spread manually to avoid local accumulation. The height of the sand pile was calculated to simulate the self-weight of the concrete. After static stabilization, the deflection was measured. Then, yellow sand was applied again to simulate dynamic load. According to the specifications, the dynamic load was taken as 2.5 kN / m² and the yellow sand as 14 kN / m². 3 The concrete density is 25 kN / m³. 3 The floor deck height is 0.18m. Calculate the static load height of yellow sand: 25 kN / m 3 ×0.18*1 / 14=0.32m; Dynamic load sand height: 2.5 * 1 / 14 = 0.18 m.

[0022] The first sand loading is a static load: lay a 320mm high sand layer, and after the load stabilizes, measure the deflection at mid-span of the I-beam main beam, I-beam secondary beam, anti-tension support, and floor deck; if the measurement results meet the requirements, then carry out the second sand loading. Second dynamic load application: 180mm high yellow sand was laid at the mid-span. After the load stabilized, the deflection at the mid-span of the main beam, secondary beam, anti-tension support, and floor deck was measured again. Measurement points were set at the junction of the main and secondary beams, at the anti-tension support, and at the mid-span of the floor slab.

[0023] Comparison of S3 deflection value and limit value According to the T / CECS1069-2022 standard, the deflection is determined by the calculated floor deck span value * 1 / 250 (in mm). With a counter-tensioning system, the deflection is much less than the limit; without a counter-tensioning system, the deflection exceeds the limit. This result indicates that the counter-tensioning system is effective.

[0024] Large-area floor decking construction can only proceed after the anti-tension system has passed the test.

[0025] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents. The foregoing description is merely a description of preferred embodiments of the invention and is not intended to limit the scope of the invention in any way. Any changes or modifications made by those skilled in the art based on the foregoing disclosure shall fall within the scope of the claims.

Claims

1. A test method for the effectiveness of a super-span floor decking anti-tension system, characterized in that: S1. Set up the experimental platform and define the taut experimental group and the non-taut control group; S2 was loaded with equivalent yellow sand on the test platform and the deflection was measured. If the deflection value of S3 is compared with the limit value, and the deflection of each point in the taut experimental group is less than the limit value, while the deflection of each point in the non-taut control group exceeds the limit value, then the anti-tension system is deemed effective.

2. The method of claim 1, wherein the method further comprises: determining the effective value of the super-span floor support plate counter-pulling system based on the first and second effective values. The test platform in S1 includes: a simulated main beam, an I-beam main beam, an I-beam secondary beam, a floor deck, concrete supports, and formwork; The simulated structure's main beams are set on a flat ground, with one beam on each side. The floor decking is laid flat on the simulated main beam, with its length direction perpendicular to the simulated main beam; the concrete supports are set on the simulated main beam, along the length direction of the main beam; the I-beam main beam is set on the concrete supports, along the length direction of the floor decking; the I-beam secondary beam is set on the I-beam main beam and parallel to the simulated main beam; the line connecting the middle concrete supports on the simulated main beam serves as the boundary, with one side designated as the tensioned experimental group and the other side as the non-tensioned control group, and the floor decking and I-beam secondary beam of the tensioned experimental group are set as a counter-tension system; after the platform is completed, formwork is erected around the edge of the platform.

3. The method of claim 2, wherein the method further comprises: determining the effective value of the super-span floor support plate counter-pulling system based on the first and second effective values. The concrete supports in S1 are 300×300×250mm cube-shaped concrete supports, with 3 on each side, for a total of 6.

4. The method of claim 2, wherein the method further comprises: determining the effective value of the super-span floor support plate counter-pulling system based on the effective value of the super-span floor support plate counter-pulling system and the effective value of the super-span floor support plate counter-pulling system. The floor decking is fixed to the main beam of the simulated structure with studs, and its length direction is perpendicular to the main beam of the simulated structure.

5. The method of claim 2, wherein the method further comprises: determining the effective value of the super-span floor support plate counter-pulling system based on the effective value of the super-span floor support plate counter-pulling system and the effective value of the super-span floor support plate counter-pulling system. The anti-pull system uses angle steel and hooks to hold the chord steel bars on the floor deck as anti-pull supports, with the hook spacing set to two hooks spaced one apart.

6. The method of claim 1, wherein the method further comprises: determining the effective value of the super-span floor support plate counter-pulling system based on the effective value of the super-span floor support plate counter-pulling system and the effective value of the super-span floor support plate counter-pulling system. S2 includes: The first load was a static load of sand; after the load stabilized, the deflection at mid-span of the main beam, secondary beam, anti-tension support, and floor deck was measured. The second sand pile load was applied, followed by dynamic loading. After the load stabilized, the deflection at mid-span of the main beam, secondary beam, anti-tension support, and floor deck was measured.

7. The method of claim 1, wherein the method further comprises: determining the effective value of the super-span floor support plate counter-pulling system based on the effective value of the super-span floor support plate counter-pulling system and the effective value of the super-span floor support plate counter-pulling system. The static load height of the yellow sand in S2 is calculated by using the equivalent simulated self-weight of the concrete with yellow sand.

8. The method of claim 7, wherein the method further comprises: determining the effective value of the super-span floor support plate counter-pulling system based on the effective value of the super-span floor support plate counter-pulling system and the effective value of the super-span floor support plate counter-pulling system. The static load height of the yellow sand pile in S2 is 320mm.

9. The method for testing the effectiveness of a super-span floor decking anti-tension system as described in claim 1, characterized in that, The deflection measurement points in S2 are arranged at the junction of the main and secondary beams, at the anti-tension support, and at the mid-span of the floor deck.

10. The method for testing the effectiveness of a super-span floor decking anti-tension system as described in claim 1, characterized in that, The limit is taken as 1 / 250 of the calculated span for the concealed working condition of the bottom surface of the floor deck.

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