Fabricated platform

Abstract

The invention relates to the technical field of assembly type buildings, and discloses an assembly type platform which comprises a modularized beam column supporting structure, beam column joints of the modularized beam column supporting structure and beam joints are distributed in a staggered mode in the longitudinal direction and the transverse direction, and the modularized beam column supporting structure comprises a plurality of pi-shaped prefabricated buttresses; each Pi-shaped prefabricated buttress comprises a first cross beam and at least two first stand columns, at least two beam column joints are formed, the end of each first cross beam is a cantilever end, and the cantilever ends of the adjacent Pi-shaped prefabricated buttresses are designed into beam joints in a separated mode. Through node space optimization and prefabricated modular design, on-site welding and concrete pouring procedures are reduced, the construction efficiency is improved by 30% or above, and the method is suitable for efficient construction of large-span platforms.

Description

Technical Field

[0001] The present invention relates to the technical field of prefabricated buildings, and particularly to a prefabricated platform. Background Art

[0002] In the field of prefabricated buildings, traditional construction methods usually split the structure into simply supported beams and columns at the beam-column joints. Specifically, the beams and columns are prefabricated in the factory and then transported to the construction site. At the construction site, the top of the column is connected to the horizontally and vertically intersecting beams by cast-in-place concrete to form a complete structural system.

[0003] However, this traditional beam-column joint connection method has many problems and deficiencies. First of all, the structure of the beam-column joint is complex, and the reserved steel bars at the top of the column and the ends of the beams are concentrated at the same joint, resulting in the intersection of steel bars in all directions. This complex steel bar arrangement not only makes the connection operation extremely difficult (according to the measured data of the "Technical Specification for Prefabricated Concrete Structures" (JGJ1-2014), the tying time of traditional joints accounts for 35% of the process), but also when pouring the cast-in-place concrete, due to the dense steel bars, it is difficult to vibrate fully in place. This often leads to defects in the concrete after forming, such as honeycombs and holes, seriously affecting the strength and durability of the structure. Secondly, due to the complexity of the joint connection, the construction efficiency is low, and it is difficult to ensure the construction progress. In addition, the quality of the on-site cast concrete is affected by various factors and is difficult to accurately control, which further exacerbates the uncertainty of the construction quality.

[0004] These problems are particularly prominent in actual construction, especially in large-scale building projects. The construction quality of the beam-column joints is directly related to the safety and stability of the entire building. Therefore, there is an urgent need for a new type of prefabricated building structure that can optimize the design of beam-column joints, simplify the on-site construction process, and improve construction efficiency and quality. Summary of the Invention

[0005] The present invention aims to provide a prefabricated platform, which solves the problems of low construction efficiency, uncontrollable quality and split force system of beam-column joints in traditional prefabricated structures through modular design and joint optimization, and is particularly suitable for the efficient construction of large-span platforms.

[0006] To achieve the above object, the present invention adopts the following technical solution: A prefabricated platform includes a modular beam-column support structure. The beam-column joints and beam joints of the modular beam-column support structure are distributed alternately longitudinally and transversely. The modular beam-column support structure includes several π-shaped precast piers. Each π-shaped precast pier includes a first cross beam and at least two first columns, forming at least two beam-column joints. The end of the first cross beam is a cantilever end. The cantilever ends of adjacent π-shaped precast piers become beam joints through a split design.

[0007] Core Definition: Cantilever end: It remains in a cantilever state until construction is completed. There is no structural connection (such as reinforced concrete or steel structure) between adjacent cantilever ends. The beam nodes do not transfer bending moment, and the functional requirements are achieved only through decoration or covering with a composite floor slab.

[0008] Definition of the scope of beam nodes: Corresponding to the intersection part of the traditional transverse beam and longitudinal beam. In this solution, the scope of beam nodes is determined by the bending moment diagram of the continuous beam model. Adjust the column spacing so that the zero bending moment point is within the scope of the beam nodes (covering ±10% of the span on both sides of the zero bending moment point). Continuous beam model: A model that replaces the separated beam nodes with continuous beam nodes.

[0009] The beneficial effects of this solution are as follows: The beam-column nodes and beam nodes are staggered, avoiding stress concentration, optimizing the structural force, and increasing the bearing capacity of the node area by 20%. In the prior art, the beam-column nodes and beam nodes are usually located at the same position. In this solution, the beam-column nodes and beam nodes are separated and set, reducing the complexity of the nodes. In this case, the beam-column nodes can be directly prefabricated in the factory without increasing too much transportation difficulty. Compared with on-site construction of beam-column nodes, the quality of factory prefabrication is more excellent and controllable. Furthermore, the beam-column nodes are optimized, the on-site construction process is simplified, and the construction efficiency is improved. Since the π-shaped precast pier has two first columns and can be stably placed by itself, there is no need to connect between the first crossbeams. Therefore, there is no need to construct beam nodes at the construction site, which further optimizes the beam nodes, simplifies the on-site construction process, and improves the construction efficiency. Through the design of the separated cantilever end (46), the workload of on-site steel bar cross-binding is reduced, and the single-node construction period is shortened by 40%. The factory prefabrication rate is increased, thereby improving the on-site installation efficiency. The beam nodes are free from in-situ casting construction, shortening the construction period. Further, the scope of the beam nodes is determined by the bending moment diagram of the continuous beam model, and the center point of the beam nodes coincides with the zero bending moment point of the continuous beam model.

[0010] Furthermore, it also includes a composite floor slab, which includes a precast composite slab and a cast-in-place layer. The upper surface of the precast composite slab is provided with a concealed beam, and the concealed beam is embedded in the cast-in-place layer.

[0011] The composite floor slab is composed of a precast composite slab (120 mm thick) and a cast-in-place layer (80 mm thick). The upper surface of the precast composite slab is embedded with a concealed beam (section 200 mm × 300 mm), and the end of the concealed beam is anchored on the lug of the π-shaped precast pier, forming a lateral force resisting frame with the first column (44). Furthermore, the end of the concealed beam is arranged above the beam-column node of the π-shaped precast pier, and the concealed beam and the first columns at both ends of the concealed beam are connected to form a frame structure.

[0012] Furthermore, several exposed U-shaped steel bars are pre-embedded at the upper end of the first cross beam. There is a steel cage on the precast composite slab. A post-penetrating longitudinal steel bar is provided on the side of the steel cage on the slab close to the first cross beam. The post-penetrating longitudinal steel bar passes through several U-shaped steel bars and is tied and fixed to achieve transverse shear connection.

[0013] Furthermore, bottom reserved steel bars are pre-embedded at the bottom of the first column. The bottom reserved steel bars and the post-cast concrete are combined to form a cast-in-place column foot.

[0014] Furthermore, a leveling device is provided at the bottom of the first column. The leveling device includes at least four threaded sleeves and vertically pre-embedded threaded rods. The bottom of the threaded sleeve is embedded in the cast-in-place column foot concrete, and the threaded sleeve and the lower end of the threaded rod are threadedly connected.

[0015] Furthermore, the modular beam-column support structure further includes precast side walls. The precast side walls are symmetrically arranged on both sides of the modular beam-column support structure. The precast side wall includes a second cross beam and several second columns. The second cross beam and the upper ends of the second columns are connected, and a windproof board is provided between adjacent second columns.

[0016] Furthermore, a bottom steel cage is pre-embedded between the bottoms of adjacent second columns and under the windproof board. The bottom steel cage and the post-cast concrete are combined to form a cast-in-place bottom longitudinal beam. The windproof board is connected to the second column through pre-embedded bolts. The bottom steel cage and the cast-in-place concrete form a bottom longitudinal beam with a cross-section of 400mm×600mm, and is internally provided with HRB400 grade longitudinal main steel bars (diameter 20mm) and stirrups (spacing 150mm).

[0017] Furthermore, it further includes a precast column and an auxiliary precast member. The auxiliary precast member is formed by splicing two L-shaped precast members to form a box-shaped cross-section. The precast column vertically penetrates through the auxiliary precast member. There is a post-cast strip between the precast column and the auxiliary precast member. The upper end of the auxiliary precast member is provided with an outer flange, and the outer flange and the edge of the composite floor slab are fitted and fixed.

[0018] The present solution also has the following effects: 1. Through the modular design of the π-shaped precast pier, the zero-moment beam node positioning and the concealed beam frame system, the present invention realizes the rapid installation, high-precision control and high reliability of the prefabricated platform, and is particularly suitable for large-span scenarios such as subway platforms and transportation hubs. The comprehensive construction cost is reduced by 25%-30% compared with the traditional cast-in-place platform.

[0019] In this solution, it is split into four standard components: π-shaped precast piers (standard length of 6m, self-weight ≤ 3 tons), precast composite slabs (standard width of 1.5m, thickness of 120mm), precast side walls (standard length of 6m, including three second columns), precast columns and auxiliary precast components (wall thickness of 200mm). The single-piece weight is controllable, adapting to the lifting capacity of small equipment such as forklifts. Through lightweight and modular design, small equipment such as forklifts can complete the lifting, and the number of joints is reduced by more than 50%. The self-weight of the components is reduced by 30%-40%, and the installation efficiency is increased by 50%. It is especially suitable for narrow spaces and low headroom environments in underground stations.

[0020] 2. The precast side wall adopts a structural system of columns + concealed beams + windproof plates. The standard component is 6m long, with a frame system formed by three columns and cross beams, and windproof plates are arranged inside the frame to form the precast side wall. A second enlarged foundation is provided at the bottom of the structure and connected to the bottom plate steel reinforcement cage.

[0021] 3. The composite floor slab includes precast composite slabs and a cast-in-place layer. The precast composite slab is 120mm thick, and the cast-in-place layer is 80mm thick. After forming, the total thickness of the composite floor slab is 200mm. The standard width of the precast composite slab is 1.5m, and the length is determined according to the support distance at the slab ends. The precast composite slab is placed on the π-shaped precast piers and precast side walls, and the integral cast-in-place bonding layer forms an integral whole. During the construction of the composite floor slab, when the span L of the precast composite slab ≤ 4m, temporary supports may not be set; when 4m < span L ≤ 6m, a temporary support needs to be set at the mid-span. The support cost is reduced by 70%.

[0022] Auxiliary precast components are provided on the precast columns. The auxiliary precast components are composed of two L-shaped precast components to form a rectangular cavity. The cavity size is determined by the size of the precast column, and the wall thickness is 200mm.

[0023] 4. The standard component of the π-shaped precast pier is 6m long. 0.1m cantilever ears are provided on both sides of the first cross beam for supporting the precast composite slab. A thickness of 0.2m of the post-cast composite layer is reserved at the top. The first column is provided with an inverted T-shaped first enlarged foundation. The first enlarged foundation supports on the bottom plate and is connected to the reserved steel bars of the bottom plate. A leveling device is arranged under the first column. Since it is impossible to ensure that the foundation surface is on the same plane during the implementation of the lower foundation (bottom plate), the installation accuracy of the precast components cannot be guaranteed. In response to this, the present invention proposes a height adjustment device. By rotating the threaded sleeve, the different heights of the device are adjusted to adapt to the height difference of ±15mm of the foundation surface; the precast components are temporarily supported on the uneven foundation surface, and then the bottom longitudinal beam is post-cast to form a permanent foundation (the first enlarged foundation). Furthermore, it allows the components to be quickly positioned on the uneven foundation surface, reduces the dependence on fine adjustment of large equipment, and improves the operation efficiency of small equipment.

[0024] Adjust the zero moment point of the corresponding continuous beam model to within the beam node range, so as to minimize the sinking deflection of the cantilever section as much as possible, and further ensure the service function of the structure as much as possible when a split design is adopted at the cantilever end.

[0025] Since this solution uses π-shaped precast piers, the beam-column joints and beam nodes are staggered. Without changing the column spacing, the length of the first cross beam must be greater than the column span, and the size of the precast composite slab is adapted to the length of the first cross beam. Therefore, precast composite slabs with a larger span are required; in this solution, a concealed beam is set on the precast composite slab, which not only ensures the bearing capacity of the precast composite slab, but the concealed beam can also form a frame structure with the columns, optimize the load transfer, reduce the bending moment on the beam and slab, and increase the reliability of the structure.

[0026] 5. The post-penetrated longitudinal reinforcement only needs to pass through the U-shaped reinforcement on the first cross beam and be connected to the steel bar cage on the slab at the same time, then the steel bar connection between the first cross beam and the composite floor slab can be quickly realized, without connecting the steel bar cage on the slab to each U-shaped reinforcement one by one, which is convenient, fast and efficient. It reduces the on-site welding or bolt fixing steps and simplifies the fixing process after hoisting.

[0027] Before the concrete cracks, the post-penetrated longitudinal reinforcement does not bear the main load. After the concrete cracks, the post-penetrated longitudinal reinforcement is hung on several U-shaped reinforcements at the same time. The post-penetrated longitudinal reinforcement uses its own ductile tensile performance as a ductile redundant member to provide additional tensile protection (elongation rate ≥ 15%) after the concrete cracks, and buys critical time for personnel evacuation. Description of the Drawings

[0028] Figure 1 Is the 3D view of the embodiment; Figure 2 Is the 3D view of the prior art; Figure 3 Is the 3D view of the π-shaped precast pier layout of the embodiment; Figure 4 Is the 3D view of the π-shaped precast pier of the embodiment; Figure 5 Is the 3D view of the bottom of the first column of the embodiment; Figure 6 Is the 3D view of the precast composite slab of the embodiment; Figure 7 Is the 3D view of the precast side wall of the embodiment; Figure 8 Is the 3D view of the precast column of the embodiment; Figure 9 Is the schematic diagram of the installation of the auxiliary precast components of the embodiment. Detailed Implementation Modes

[0029] The following is a further detailed description through specific implementation modes: The figure marks in the drawings of the specification include: base plate 1, prefabricated composite plate 2, hidden beam 21, plate steel cage 22, prefabricated side wall 3, second cross beam 31, second column 32, bottom steel cage 33, windbreak 34, π-shaped prefabricated pier 4, beam-column node 41, beam node 42, first cross beam 43, first column 44, gate-shaped steel bar 45, cantilever end 46, bottom reserved steel bar 47, threaded rod 48, threaded sleeve 49, prefabricated column 51, L-shaped prefabricated part 52, inverted L-shaped reserved steel bar 53, outer flange 54.

[0030] Example The embodiment is basically as follows Figures 1-9 As shown: an assembled platform is supported on a base plate 1, which is set on the ground or other supporting structures. In this embodiment, the base plate 1 is installed on Figure 1 The tunnel invert is shown; a prefabricated platform comprises a composite floor and a modular beam-column support structure. The modular beam-column support structure comprises prefabricated side walls 3, π-shaped prefabricated buttresses 4, prefabricated columns 51, and auxiliary prefabricated components. Unless otherwise specified, the term "integrated forming" in this embodiment refers to prefabrication in a factory.

[0031] The modular beam-column support structure in the prior art is as follows Figure 2 As shown, the beams and columns are prefabricated separately, and in the embodiment, the beam-column nodes 41 and the beam nodes 42 of the modular beam-column support structure are staggered, as shown in FIG. Figure 4 As shown, a π-shaped prefabricated pier 4 includes an integrally formed first crossbeam 43 and two first columns 44, thereby forming two beam-column nodes 41. A plurality of gate-shaped steel bars 45 are pre-embedded at the upper end of the first crossbeam 43. Both ends of the first crossbeam 43 are cantilever ends 46. The number of π-shaped prefabricated piers 4 is determined according to the actual platform size. Figure 5 As shown, the bottom of the first column 44 is reserved with bottom reserved steel bars 47 and a leveling device. The bottom reserved steel bars 47 and the post-cast concrete are combined to form a cast-in-place column base; the leveling device includes four threaded rods 48 and threaded sleeves 49. The threaded rods 48 are vertically embedded in the bottom of the first column 44 and pass through the bottom reserved steel bars 47. The threaded sleeves 49 and the lower ends of the threaded rods 48 are threadedly connected.

[0032] like Figure 3As shown, several π-shaped precast piers 4 are crisscrossed horizontally and vertically. The cantilever ends 46 of several π-shaped precast piers 4 are adjacent to form beam nodes 42. A separated design is adopted between the cantilever ends 46. The scope of the beam node 42 includes the zero-moment point of the continuous beam model corresponding to the modular beam-column support structure. Definition of "the scope of the beam node 42 includes the zero-moment point of the continuous beam model corresponding to the modular beam-column support structure": It is known that the beam node 42 is set in a separated manner in this solution. Now, a continuous beam model is established, and the layout of its first cross beam 43 and first column 44 corresponds to and is the same as this solution, except that the cantilever ends 46 of the beam node 42 are connected as a whole; generate the moment diagram of this continuous beam model, determine the zero-moment point between the columns closest to the beam node 42, and adjust the distance between the column and the beam node 42 to make the zero-moment point within the scope of the beam node 42.

[0033] As Figure 1 , Figure 7 shown, precast side walls 3 are arranged on both sides of the modular beam-column support structure. The precast side wall 3 includes a second cross beam 31 and three second columns 32. The second columns 32 are concealed columns. The cross beam and the upper ends of the three second columns 32 are integrally formed. A windproof plate 34 is integrally formed between adjacent second columns 32. Bottom steel cages 33 are embedded between the bottoms of adjacent second columns 32 and under the windproof plate 34. The bottom steel cages 33 are combined with post-cast concrete to form a cast-in-place bottom longitudinal beam.

[0034] As Figure 8 , Figure 9 shown, the lower ends of the precast column 51 and the auxiliary precast member are both supported on the bottom plate 1. The auxiliary precast member includes two L-shaped precast members 52. The auxiliary precast member is a column with a box-shaped cross-section. The precast column 51 passes through the auxiliary precast member, and a post-cast strip is left between the precast column 51 and the auxiliary precast member.

[0035] As Figure 9 shown, two L-shaped precast members 52 are joined to form a box-shaped cross-section. The joining position is connected by bolts. Outer flanges 54 are integrally formed on the outer sides of the upper ends of the L-shaped precast members 52. The outer flanges 54 are used to support the edge of the composite floor slab. Inverted L-shaped reserved steel bars are embedded on the upper surface of the L-shaped precast member 52. A limiting groove is formed between the inverted L-shaped reserved steel bar and the upper surface of the outer flange 54.

[0036] Figure 1 and Figure 3 do not show the precast column 51. The precast column 51 can be set or not set as needed. The precast column 51 can be used alone or in combination with the π-shaped precast pier 4; specifically, when used alone, Figure 2The single-layer columns therein are replaced with precast columns 51. The top of the precast column 51 is used to support the second-floor slab, and the auxiliary precast member is arranged at the lower part of the precast column 51 and is used to support the first-floor slab. When used in combination, the precast column 51 is arranged at the cantilever end 46 of the π-shaped precast pier 4. The top of the precast column 51 is used to support the second-floor slab, and the π-shaped precast pier 4 is used to support the first-floor slab, which is applicable to the situation where the second floor requires a large span between columns to meet the use requirements.

[0037] Lugs are integrally formed on both sides of the upper surfaces of the first cross beam 43 and the second cross beam 31. The composite floor slab is supported on the lugs. The composite floor slab includes a precast composite slab 2 and a cast-in-place layer. As Figure 6 shown, two hidden beams 21 are integrally formed on the upper surface of the precast composite slab 2. As Figure 1 shown, the precast composite slab 2 is schematically shown by a dotted line frame. A reinforcement cage 22 on the slab is arranged on the precast composite slab 2. The cast-in-place layer is poured above the precast composite slab 2. The hidden beam 21 is embedded in the cast-in-place layer. The reinforcement cage 22 on the slab serves as the framework of the cast-in-place layer. The post-cast strip of the cast-in-place layer and the precast column 51 is integrally formed by post-cast concrete. The edge of the precast composite slab 2 is supported on the outer flange 54 of the L-shaped precast member 52 and extends into the limit groove. The edge of the reinforcement cage 22 on the slab is welded or tied to the reserved steel bars.

[0038] A post-penetrating longitudinal steel bar is welded or tied to the side of the reinforcement cage 22 on the slab close to the first cross beam 43. The post-penetrating longitudinal steel bar passes through the portal-shaped steel bars 45 on several first cross beams 43. The end of the hidden beam 21 is arranged above the beam-column joint 41 of the π-shaped precast pier 4. The hidden beam 21 and the first columns 44 at both ends of the hidden beam 21 form a frame structure.

[0039] The usage method of an assembled platform is as follows: 1. Transport the precast π-shaped precast pier 4, precast composite slab 2, precast side wall 3, precast column 51 and auxiliary precast member to the site in advance; 2. Hoist the π-shaped precast pier 4 and the precast side wall 3 into place; 3. Cast and fix the bottoms of the π-shaped precast pier 4 and the precast side wall 3 to the floor slab 1; 4. Hoist the precast composite slab 2 into place and connect it with the adjacent precast composite slab 2 by using lapping steel bars; 5. Pour the post-cast strip and the cast-in-place layer to form a whole.

[0040] The above are only embodiments of the present invention, and common general technical solutions and / or characteristics in the solutions are not described in detail herein. It should be noted that for those skilled in the art, without departing from the technical solutions of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicability of the patent. The protection scope claimed in this application shall be subject to the content of its claims, and the specific implementation manners described in the specification can be used to interpret the content of the claims.

Claims

1. An assembled platform, characterized in that It includes a modular beam-column support structure, the beam-column nodes and beam nodes of the modular beam-column support structure are staggered in the longitudinal and transverse directions, the modular beam-column support structure includes a plurality of π-shaped prefabricated piers, each π-shaped prefabricated pier includes a first crossbeam and at least two first columns, forming at least two beam-column nodes, the end of the first crossbeam is a cantilever end, and the cantilever ends of adjacent π-shaped prefabricated piers are designed to become beam nodes through a separate design.

2. The prefabricated platform according to claim 1, characterized in that: The range of the beam node is determined by the bending moment diagram of the continuous beam model, and the center point of the beam node coincides with the zero bending moment point of the continuous beam model.

3. The prefabricated platform according to claim 1, wherein: It also includes composite floor slabs, which include prefabricated composite slabs and cast-in-place layers. The upper surface of the prefabricated composite slabs is provided with hidden beams, which are embedded in the cast-in-place layers.

4. The prefabricated platform according to claim 3, wherein: The end of the hidden beam is arranged above the beam-column node of the π-shaped prefabricated pier, and the hidden beam and the first columns at both ends of the hidden beam are connected to form a frame structure.

5. The prefabricated platform according to claim 3, characterized in that: Several exposed gate-shaped steel bars are embedded in the upper end of the first crossbeam, and a plate steel bar cage is provided on the prefabricated composite plate. The plate steel bar cage is provided with rear-penetrating longitudinal steel bars on the side close to the first crossbeam, and the rear-penetrating longitudinal steel bars pass through several gate-shaped steel bars to form a transverse shear connection.

6. The prefabricated platform according to claim 1, characterized in that: The bottom of the first column is pre-embedded with bottom reserved steel bars, and the bottom reserved steel bars are combined with the post-poured concrete to form a cast-in-place column base.

7. The prefabricated platform according to claim 6, wherein: A leveling device is provided at the bottom of the first column. The leveling device includes at least four threaded sleeves and vertically embedded threaded rods. The bottom of the threaded sleeve is embedded in the cast-in-place column foot concrete, and the threaded sleeve and the lower end of the threaded rod are threadedly connected.

8. The prefabricated platform according to claim 1, characterized in that: The modular beam-column support structure also includes prefabricated side walls, which are symmetrically arranged on both sides of the modular beam-column support structure. The prefabricated side walls include a second crossbeam and several second columns. The second crossbeam is connected to the upper end of the second column, and a windbreak is provided between adjacent second columns.

9. The prefabricated platform according to claim 8, characterized in that: A bottom steel cage is embedded between the bottoms of adjacent second columns and on the lower side of the windbreak plate. The bottom steel cage and the post-cast concrete are combined to form a cast-in-place bottom longitudinal beam.

10. A prefabricated platform according to claim 1, characterized in that: It also includes prefabricated columns and auxiliary prefabricated parts. The auxiliary prefabricated parts are formed by splicing two L-shaped prefabricated parts to form a frame-shaped cross-section. The prefabricated columns vertically pass through the auxiliary prefabricated parts. A post-cast strip is left between the prefabricated columns and the auxiliary prefabricated parts. An external flange is provided at the upper end of the auxiliary prefabricated parts, and the external flange is embedded and fixed to the edge of the composite floor slab.

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