Fabricated beam and plate and splicing mode thereof

Abstract

The invention discloses an assembly type beam and plate and a splicing method thereof, and relates to the field of building energy-saving assembly type structures, the splicing mode of a prefabricated concrete floor is divided into a one-way plate and a two-way plate, the splicing mode of the one-way plate is that two splicing plates at the half position of the total length are spliced in a step sawtooth shape and are anchored through split bolts, and the splicing mode of the two-way plate is that two splicing plates are spliced in a step sawtooth shape at the half position of the total length; the vertical constraint of the prefabricated concrete beam to the floor slab is strong, but the rotation constraint of the prefabricated concrete beam to the floor slab is weak, the plate blocks of the prefabricated concrete floor slab are divided according to the plastic hinge line position of the plastic hinge line theory under the effect of four-side simple support, and the joint of the four plate blocks adopts the same splicing mode as that of a one-way plate. The splicing position of the prefabricated concrete beams is located at the middle point of the inflection point (the bending moment is 0) and the middle position of the beams (the shearing force is 0), and the prefabricated concrete beams are connected in a step sawtooth-shaped splicing mode and anchored through split bolts. And the overlapping junction of the beam and the plate is aligned with the overhanging part of the pre-embedded U-shaped steel of the prefabricated concrete beam by adopting a prefabricated concrete floor reserved hole, and is fastened and connected by using a bolt. The splicing mode can be used for standardized mass production, is not influenced by other uncertain factors such as weather, is more reliable in quality aspect, can effectively save human resources, shortens the construction period, greatly reduces the generation of construction wastes, saves water, electricity and materials, and is environment-friendly.

Description

Technical Field

[0001] An assembled and spliced ​​beam and plate and a method thereof. Background Art

[0002] Prefabricated reinforced concrete structure is one of the important directions of building structure development in my country. It is conducive to the development of my country's building industrialization, improving production efficiency and saving energy, developing green and environmentally friendly buildings, and is conducive to improving and ensuring the quality of construction projects. Compared with cast-in-place concrete construction methods, prefabricated structures are conducive to green construction, because prefabricated construction can better meet the requirements of green construction such as land saving, energy saving, material saving, water saving and environmental protection, and reduce the negative impact on the environment, including reducing noise, preventing dust, reducing environmental pollution, clean transportation, reducing site interference, saving water, electricity, materials and other resources and energy, and following the principle of sustainable development. Summary of the invention

[0003] The purpose of the present invention is to provide a method for splicing assembled beams and plates and beam-slabs, which can save construction time and cost by making the construction of prefabricated components more convenient.

[0004] To achieve the above-mentioned purpose, the present invention provides a prefabricated beam and plate and a beam-plate splicing method, specifically: the splicing method of the precast concrete floor slab is divided into two forms: one-way slab and two-way slab. The splicing method of the one-way slab is a step-zigzag splicing of two splicing plates at half of the total length, and anchored with tension bolts. The precast concrete beam has a strong vertical constraint on the floor slab but a weak rotation constraint on it; the plate division of the precast concrete floor slab is divided according to the position of the plastic hinge line of the plastic hinge line theory under the action of four-sided simple support, and the connection of the four plates adopts the same splicing method as the one-way slab. The splicing position of the precast concrete beam is located at the midpoint between the inflection point (bending moment is 0) and the middle position of the beam (shear force is 0). The connection method between the precast concrete beams is a step-zigzag splicing, and anchored with tension bolts. The precast concrete floor slab reserved holes are used at the overlapped junction of the beam and the slab to align with the outer part of the precast concrete beam embedded U-shaped steel, and are fastened with bolts.

[0005] For the above-mentioned two forms of concrete two-way slab and one-way slab, when the ratio of the long side to the short side of the floor slab is less than 2, it is a two-way slab; when the ratio of the long side to the short side of the floor slab is between 2 and 3, it should be considered as a two-way slab; when the ratio of the long side to the short side of the floor slab is greater than 3, it is a one-way slab.

[0006] The above-mentioned one-way slab splicing method is that the entire one-way slab is spliced ​​together by two prefabricated slabs, and an overhanging structure of a certain size is reserved at the splicing position of the two slabs. The splicing surface is a serrated structure with reserved bolt holes, which is convenient for fastening the overhanging parts of the slabs with bolts after splicing.

[0007] The above-mentioned restraining effect of the precast concrete beam on the floor slab will cause vertical and horizontal displacements of the floor slab and the beam under the uniformly distributed load; the vertical and horizontal displacements of the floor slab will increase with the increase of load, but the horizontal displacement of the slab in the yield state and the limit state is less than one tenth of the vertical displacement, so the influence of the horizontal displacement on the internal force distribution of the floor slab can be ignored, and the horizontal displacement of the floor slab is positively correlated with the rotation constraint of the beam on the slab, so the influence of the rotation constraint of the beam on the slab can be ignored. Therefore, when analyzing the floor slab, it can be analyzed according to the theoretical model of the bearing capacity of a simply supported rectangular slab on four sides.

[0008] The above-mentioned plate division method of the two-way slab is based on the position of the plastic hinge line in the plastic hinge line theory. The plastic hinge line theory is a common method for the ultimate load analysis of reinforced concrete slabs. It studies various possible failure patterns of the slab and determines the possible allowable displacement field. According to the upper limit theorem of the structural limit analysis method, the ultimate load value of the reinforced concrete slab can be obtained. The ultimate load obtained by the plastic hinge line theory is its upper limit value. The plastic hinge line theory can accurately give the ultimate bearing capacity of the reinforced concrete slab, and the actual failure pattern of the reinforced concrete slab is also consistent with the failure mechanism given by the calculation. The reinforced concrete slab forms several plastic hinge lines under the limit state. The plastic hinge lines divide the slab into several plates. All longitudinal steel bars passing through the plastic hinge lines have reached yield, and the resistance bending moment along the section of the plastic hinge line has reached the ultimate bending moment value. The plastic hinge line that bears positive bending moment is called a positive plastic hinge line, and its crack appears on the lower surface of the slab; the plastic hinge line that bears negative bending moment is called a negative plastic hinge line, and its crack appears on the upper surface of the slab.

[0009] In the above-mentioned overlapping method between the two-way plate plates, the two-way plate is divided into 4 pieces according to the position of the plastic hinge line, and a certain size of overhanging structure is reserved at the splicing position between the plates. The splicing surface is a serrated structure with reserved bolt holes, which is convenient for fastening the overhanging parts between the plates with bolts after splicing.

[0010] The splicing position of the above-mentioned precast concrete beam is located at the midpoint between the inflection point (bending moment is 0) and the middle position of the beam (shear force is 0). The rotation constraint of the column on the beam and the vertical constraint at the support are strong. Therefore, the support form at both ends of the beam is equivalent to a fixed support. The inflection point of the fixed-supported beam at both ends under the action of uniformly distributed load is (1 / 2-√6 / 6)l away from the end support, where l is the length of the beam, and the position where the shear force of the fixed-supported beam at both ends under the action of uniformly distributed load is zero is located in the middle of the span of the beam. Therefore, considering the positions with smaller bending moment and shear force, the midpoint of the two is selected as the splicing position of the beam.

[0011] In the above-mentioned splicing method of precast concrete beams, a certain size of overhanging structure is reserved at the splicing position between the precast concrete beams, and the splicing surface thereof is a serrated structure with reserved bolt holes, so as to facilitate fastening with bolts after the splicing is completed.

[0012] In the above-mentioned splicing method at the junction of the beam and the slab, U-shaped steel is embedded in the precast concrete beam and extends outward to a certain size from the top of the beam. The reserved holes in the precast concrete floor slab are used to align the protruding part of the embedded U-shaped steel in the precast concrete beam at the overlap junction of the beam and the slab, and are fastened with bolts.

[0013] Compared with the prior art, the advantages of the present invention are:

[0014] Prefabricated building components can be mass-produced in a standardized manner, are not affected by weather or any other uncertain factors, are more reliable in quality, can effectively save human resources, shorten construction time, and increase human control over the construction period. The production efficiency is much higher than manual work.

[0015] After the prefabricated components are processed, they are directly transported to the construction site for assembly. This construction technology reduces material waste during the construction process, and also greatly reduces the generation of construction waste, saving water, electricity, materials and the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of splicing the precast concrete one-way slab of the present invention;

[0017] Figure 2 It is a schematic diagram of the division of the concrete two-way slab of the present invention;

[0018] Figure 3 It is a schematic diagram of splicing the precast concrete bidirectional slab of the present invention;

[0019] Figure 4 It is a schematic diagram of the force analysis and splicing of the precast concrete beam of the present invention;

[0020] Figure 5 It is a schematic diagram of the splicing at the junction of the concrete beam and slab of the present invention. DETAILED DESCRIPTION

[0021] refer to Figure 1 The splicing method of the one-way plate is that the entire one-way plate is made up of two prefabricated plates, and a certain size of overhanging structure is reserved at the splicing part of the two plates. The splicing surface is a serrated structure with reserved bolt holes, which is convenient for fastening with bolts after splicing.

[0022] refer to Figure 2The plate division method of the two-way slab is based on the position of the plastic hinge line in the plastic hinge line theory. The plastic hinge line theory is a commonly used method for the ultimate load analysis of reinforced concrete slabs. It studies various possible failure patterns of the slab and determines the possible allowable displacement field. According to the upper limit theorem of the structural limit analysis method, the ultimate load value of the reinforced concrete slab can be obtained. The ultimate load obtained according to the plastic hinge line theory is its upper limit value. The plastic hinge line theory can give the ultimate bearing capacity of the reinforced concrete slab more accurately, and the actual failure pattern of the reinforced concrete slab is also consistent with the failure mechanism given by the calculation. The reinforced concrete slab forms several plastic hinge lines under the limit state. The plastic hinge lines divide the slab into several plates. All longitudinal steel bars passing through the plastic hinge lines have reached yield, and the resistance bending moment along the section of the plastic hinge line has reached the ultimate bending moment value. The plastic hinge line that is subjected to positive bending moment is called a positive plastic hinge line, and its cracks appear on the lower surface of the slab; the plastic hinge line that is subjected to negative bending moment is called a negative plastic hinge line, and its cracks appear on the upper surface of the slab. Among them, Figure 2 Where n represents the position parameter of the two-way plate; μ is the orthogonal parameter, i.e., the ratio of the yield moments in the two directions of the two-way plate; M x M is the yield moment of the plate along the long side; y is the yield moment of the plate along the short side.

[0024] refer to Figure 3 The overlapping method of the two-way plate is to divide it into 4 pieces according to the position of the plastic hinge line. An overhanging structure of a certain size is reserved at the joint between the plates. The joint surface is a serrated structure with reserved bolt holes, which is convenient for fastening with bolts after the splicing is completed.

[0025] refer to Figure 4 The splicing position of the precast concrete beam is located at the midpoint between the inflection point (bending moment is 0) and the middle position of the beam (shear force is 0). The rotation constraint of the column on the beam and the vertical constraint at the support are strong. Therefore, the support form at both ends of the beam is equivalent to a fixed support. The inflection point of the fixed beam at both ends under the uniform load is (1 / 2-√6 / 6)l away from the end support, where l is the beam length, and the position where the shear force of the fixed beam at both ends under the uniform load is zero is located in the middle of the beam span. Therefore, considering the position with smaller bending moment and shear force, the midpoint of the two is selected as the splicing position of the beam. At the same time, a certain size of overhanging structure is reserved at the splicing part between the precast concrete beams. The splicing surface is a serrated structure with reserved bolt holes, which is convenient for fastening with bolts after splicing.

[0026] refer to Figure 5 In the above-mentioned splicing method of the junction of the beam and the slab, the U-shaped steel is embedded in the precast concrete beam and extends outward from the top of the beam to a certain size. The reserved holes in the precast concrete floor slab are used to align the protruding part of the embedded U-shaped steel in the precast concrete beam at the overlap junction of the beam and the slab, and are fastened with bolts.

Claims

1. An assembled beam and plate and a method for splicing the same, characterized in that: The splicing methods of precast concrete floor slabs are divided into two forms: one-way slabs and two-way slabs. The splicing method of the one-way slab is to splice the two splicing plates in a step-zigzag manner at half the total length, and anchor them with tension bolts. The precast concrete beam has a strong vertical constraint on the floor slab but a weak rotation constraint on it; the plate division of the precast concrete floor slab is divided according to the position of the plastic hinge line in the plastic hinge line theory under the action of four-sided simple support, and the connection of the four plates adopts the same splicing method as the one-way slab. The splicing position of the precast concrete beam is located at the midpoint between the inflection point (bending moment is 0) and the middle position of the beam (shear force is 0). The connection method between the precast concrete beams is a step-zigzag splicing, and anchored with tension bolts. The precast concrete floor slab reserved holes are used at the overlap junction of the beam and the slab to align with the outer extension of the precast concrete beam embedded U-shaped steel, and then fastened with bolts.

2. According to the two forms of concrete two-way slab and one-way slab as described in claim 1, it is characterized in that: When the ratio of the long side to the short side of the floor slab is less than 2, it is a two-way slab; when the ratio of the long side to the short side of the floor slab is between 2 and 3, it should be considered as a two-way slab; when the ratio of the long side to the short side of the floor slab is greater than 3, it is a one-way slab.

3. The one-way slab splicing method according to claim 1 is characterized in that: The entire one-way slab is made up of two prefabricated slabs spliced ​​together, and an overhanging structure of a certain size is reserved at the splicing position of the two slabs. The splicing surface is a serrated structure with reserved bolt holes, which is convenient for fastening with bolts after splicing.

4. The restraining effect of the precast concrete beam on the floor slab according to claim 1 is characterized in that: Under the action of uniformly distributed load, the floor slab and beam will produce vertical and horizontal displacements; the vertical and horizontal displacements of the floor slab will increase with the increase of load, but the horizontal displacement of the plate in the yield state and the limit state is less than one tenth of the vertical displacement, so the influence of the horizontal displacement on the internal force distribution of the floor slab can be ignored, and the horizontal displacement of the floor slab is positively correlated with the rotation constraint of the beam on the slab, so the influence of the rotation constraint of the beam on the slab can be ignored. Therefore, when analyzing the floor slab, it can be analyzed according to the four-sided simply supported rectangular slab model.

5. The plate division method of the two-way slab according to claim 1 is based on the position of the plastic hinge line in the plastic hinge line theory, characterized in that: The plastic hinge line theory is a commonly used method for ultimate load analysis of reinforced concrete slabs. It studies various possible failure patterns of the slab and determines the possible allowable displacement field. According to the upper limit theorem of the structural limit analysis method, the ultimate load value of the reinforced concrete slab can be obtained. The ultimate load obtained according to the plastic hinge theory is its upper limit value. The plastic hinge theory can give the ultimate bearing capacity of the reinforced concrete slab more accurately, and the actual failure diagram of the reinforced concrete slab is also consistent with the failure mechanism given by the calculation. The reinforced concrete slab forms several plastic hinges under the limit state. The plastic hinges divide the slab into several plates. All longitudinal steel bars passing through the plastic hinges have reached yield, and the resistance bending moment along the section of the plastic hinge has reached the ultimate bending moment value. The plastic hinge that is subjected to positive bending moment is called a positive plastic hinge, and its cracks appear on the lower surface of the slab; the plastic hinge that is subjected to negative bending moment is called a negative plastic hinge, and its cracks appear on the upper surface of the slab.

6. The overlapping method between the two-way plate segments according to claim 1 is characterized in that: The two-way slab is divided into four pieces according to the position of the plastic hinge line. An overhanging structure of a certain size is reserved at the joint between the plates. The joint surface has a serrated structure and reserved bolt holes, which is convenient for fastening with bolts after the splicing is completed.

7. The splicing position of the precast concrete beam according to claim 1 is located at the midpoint between the inflection point (bending moment is 0) and the middle position of the beam (shear force is 0), characterized in that: The rotational constraint of the column on the beam and the vertical constraint at the support are strong, so the support form at both ends of the beam is equivalent to a fixed support. The inflection point of the fixed-supported beams at both ends under the uniformly distributed load is (1 / 2-√6 / 6)l away from the end support, where l is the length of the beam, and the position where the shear force of the fixed-supported beams at both ends under the uniformly distributed load is zero is located in the middle of the beam span. Therefore, considering the positions with smaller bending moments and shear forces, the midpoint of the two is selected as the splicing position of the beam.

8. The method for splicing precast concrete beams according to claim 1 is characterized in that: An overhanging structure of a certain size is reserved at the joints between precast concrete beams. The joint surface has a serrated structure and reserved bolt holes, which facilitates fastening with bolts after the joints are completed.

9. The method for splicing the interface between beams and plates according to claim 1 is characterized in that: U-shaped steel is embedded in the precast concrete beam and extends outward to a certain size from the top of the beam. The reserved holes in the precast concrete floor slab are used to align the protruding part of the embedded U-shaped steel in the precast concrete beam at the overlap junction of the beam and the slab, and are fastened with bolts.

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