CN105625568B - Assembly concrete orthogonal spatial space lattice boxlike tube-in-tube structure - Google Patents

Abstract

The invention relates to a prefabricated concrete orthogonal space grid box-type tube-in-tube structure, the grid of the horizontal fasting floor is equal to the grid of the vertical grid frame, and they are rigidly connected at the intersection; The shear walls around the central reinforced concrete core tube are rigidly connected at the position of the hollow floor, and the floor is rigidly connected with the central core tube shear wall and the vertical grid frame respectively to form a grid box structure. The grid box structure and the central concrete core tube form an orthogonal box-type tube-in-tube structure. After the horizontal hollow floor and the vertical grid frame are prefabricated in units, they are then installed in layers; the amount of concrete poured after assembling the nodes accounts for the total Within 5% of the total, the amount of formwork used and man-hours are greatly reduced, the construction progress is improved, and the overall project cost is reduced by about 20%.

Description

Prefabricated Concrete Orthogonal Space Grid Box Tube-in-Tube Structure

technical field

The invention relates to a high-rise and super-high-rise concrete structure, in particular to a prefabricated monolithic concrete orthogonal space grid box-type tube-in-tube structure, which belongs to the technical field of construction.

technical background

In 2014, the Ministry of Housing and Urban-Rural Development issued the "Technical Regulations for Prefabricated Concrete Structures" (JGJ1-2014), mainly for traditional concrete structures, such as frame, frame. shear, frame. tube and other structural systems, as shown in Figure 1. Traditional concrete frame and core tube structure, the central core tube shear wall is cast on site, and the surrounding frame columns, beams, secondary beams and slabs are prefabricated. It is prefabricated layer by layer from bottom to top. Post-cast areas are set at the joints of the columns and beams, and the concrete is poured twice after the steel bars are connected to form a whole. For high-rise and super high-rise buildings, the surrounding frame beams and columns are often fat beams and columns, the light ones are several tons, the heavy ones are more than ten tons, and they are all single. It is difficult to transport, install and manufacture. For super high-rise buildings, traditional It is difficult to reduce the project cost to achieve the effect of energy saving and emission reduction if the structural system is assembled in an integrated construction.

Contents of the invention

The problem to be solved by the present invention is to address the above deficiencies, and to provide a prefabricated integral concrete orthogonal space grid box-type tube-in-tube structure and manufacturing method. After adopting the structure and method, the following objectives are achieved:

1. Buildings are unitized and assembled.

2. Reduce the amount of post-cast concrete engineering.

3. Improve the construction quality and speed up the construction progress.

4. Reduce project cost.

5. Factory prefabrication, on-site assembly, and civilized construction.

In order to solve the above technical problems, the present invention adopts the following technical solutions: prefabricated concrete orthogonal vertical space grid box-type tube-in-tube structure, characterized in that the grid of the horizontal hollow floor is equal to the grid of the vertical grid frame , and are rigidly connected to each other at the intersection;

The horizontal hollow floor and the vertical grid frame are unitized and prefabricated, and then installed in layers.

An optimized scheme, the floor and the shear wall around the central reinforced concrete core tube are rigidly connected at the location of the empty-web floor.

Further, the floor is rigidly connected with the shear wall of the central core tube and the vertical grid frame respectively to form a grid box structure.

Further, the grid box structure and the central concrete core tube form an orthogonal and positive box-type tube-in-tube structure.

Based on the above-mentioned prefabricated concrete orthogonally placed space grid box-type tube-in-tube structure, the manufacturing method of the fabricated concrete orthogonally placed space grid box-type tube-in-tube structure includes:

Divide the vertical grid frame and the horizontal hollow grid floor into several grid units, and then prefabricate the assembled units, and then install them layer by layer at the construction site.

Further, the prefabrication engineering volume accounts for 85% of the total engineering volume.

Further, the central concrete core tube is poured layer by layer from bottom to top on site;

A tower crane is installed inside the concrete core tube for hoisting and installation of assembled units.

Furthermore, after the construction of 2-3 floors of the core tube, the surrounding vertical grid frame assembly units are installed first, and the grid frame columns of each floor are prefabricated at 45° to assemble short cantilever beams at the floor level. The 45° included angle of the floor is spliced with hollow beams, and the installation frame is installed when the wall frame is installed;

After the surrounding grid frame of each layer is installed in place, the concrete hollow grid prefabricated units are installed layer by layer. After the tower crane is hoisted in place, the support frame is set to support in place at each section.

Further, a four-point-supported reinforced truss floor deck is placed at the support of the square grid hollow floor, and the formwork is only set at the splicing position.

Further, at the node position, the longitudinal reinforcement of the shear key and the upper reinforcement of the upper chord are all penetrated into the reserved stirrups, and then the reinforced truss floor deck is placed at the support position of the four corners of the grid, and then the longitudinal reinforcement of the upper chord of the vierendeel beam is set to be reserved. Inside the stirrups, the upper and lower chord splicing positions between the assembled units are connected with longitudinal steel bars. After the formwork is installed at the upper and lower chord splicing positions, the joints and floor decks are poured with a one-time post-poured concrete, and the hollow grid After the unit and the floor deck are poured concrete twice, the floor is formed as a whole, and the interlayer for laying horizontal pipelines is left in the middle. When the vertical and horizontal concrete grids are spliced, the concrete is poured and cured, and the concrete is formed. Orthogonal space network Box-in-tube structure.

The present invention adopts the above technical scheme, and compared with the prior art, has the following advantages:

1. The grid of the horizontally orthogonal and vertical hollow floor of the building structure of the present invention is equal to the grid of the vertical grid frame, and they are rigidly connected at the intersection to form a mechanical model of the space grid box structure, so that the structure The mechanical properties and lateral stiffness of the system have been greatly improved, so that the horizontal hollow floor and the vertical grid frame can be prefabricated and then installed in layers.

2. After the prefabricated unit is meshed, the cross-sectional size of the component is small, the weight is light, and the unit coverage area is large. The amount of concrete poured after assembling the joints accounts for less than 5% of the total.

3. The prefabricated components are also gridded, the integrity and spatial effect are enhanced, and the building area covered by the assembled components is also large. Except for the central core tube which is still cast on site (15%), the rest of the large-area (85%) components are prefabricated Prefabricated type, manufactured in the prefabrication field, prefabricated assembly integral construction according to the national industry standard (JGJ1-2014), after the splicing parts are strongly connected to the steel bars, the secondary pouring concrete is connected as a whole, which greatly reduces the workload of on-site pouring concrete , Only set the formwork at the splicing position, greatly reduce the amount of formwork usage and man-hours, improve the construction progress, save formwork and promote the development of construction industrialization.

4. The overall project cost decreased by about 20%.

5. Compared with the traditional concrete frame and core tube structure system, the lateral stiffness is increased by 20%-25%.

6. The thickness of the floor is reduced. Under the condition that the maximum height of the tower and the net height of the floors are the same, the storey height is reduced and the number of floors of the tower is increased.

7. The thickness of the floor δ=(1/25-1/30)L (depth), the indoor rooms can be divided freely, not subject to the restriction of "where there are walls, there must be beams", and the hollow center of the slab can pass through the horizontal pipeline.

The present invention will be further described below in conjunction with drawings and embodiments.

Description of drawings

Accompanying drawing 1 is the standard floor structure layout diagram of concrete frame core tube structure in traditional high-rise and super high-rise office buildings;

Accompanying drawing 2 is the standard floor structure layout diagram of the concrete orthogonally placed space grid box-type tube-in-tube structure in high-rise and super high-rise office buildings of the present invention;

Accompanying drawing 3 is the layout diagram of the prefabricated grid unit in Figure 2, A1 and A2 unit geometric dimensions are the same, but the reinforcement is different;

Accompanying drawing 4 is the plane geometric dimension drawing of prefabricated concrete A1, A2 mesh fasting unit in Fig. 3, and the supporting bracket is the supporting point for laying down the steel bar truss floor deck;

Accompanying drawing 5 is the steel bar truss floor deck plane and the section view of each grid of the floor in the present invention;

Accompanying drawing 6 is the detail structure of A node orthogonal to A unit in Fig. 4;

Attached drawing 7 is the section structure of joint A in Figure 6, the upper chord stirrups are reserved on the prefabricated parts, the floor deck is installed and the steel bars are patched, and then the higher level concrete is poured;

Accompanying drawing 8 is the entire floor formed after the concrete hollow grid unit and the floor slab are poured concrete twice in the present invention;

Accompanying drawing 9 is the detailed structure of A node and B node in Fig. 8, the post-cast concrete parts are indicated by thin dots, and the thick dotted line is the internal reinforcement of prefabricated components;

Accompanying drawing 10 is the middle and super high-rise (100m ≤ H ≤ 216m) assembled integral concrete orthogonal vertical space grid box-in-tube structure of the present invention, and a schematic layout diagram of the external grid frame prefabricated units A and B;

Accompanying drawing 11 is the structural diagram of unit A of prefabricated concrete grid in Fig. 10.

Detailed ways

Example 1, as shown in Figure 2, if the concrete is placed in a vertically spaced grid box-type tube-in-tube structure, if it is still cast on site, the workload of the formwork will be large. Although they are all small components, the number of nodes will increase significantly. As shown in Figure 2, the amount of concrete joints for each additional floor is more than three times that of the structure shown in Figure 1. If the site-cast formwork is still used, the amount of labor and time is large, and if the prefabricated assembly integral construction method is used, it will achieve twice the result with half the effort.

As shown in Figure 2, the concrete orthogonal space grid box-type tube-in-tube structure has a horizontal concrete hollow floor with a×a=2.8m×2.8m=9.84m ² square fasting grid, and the upper and lower chords of the hollow beam 1/3 is rigidly connected to the concrete shear wall of the core tube, and the other 2/3 of the vierendeel beams are rigidly connected to each other orthogonally, and the vierendeel beams are rigidly connected to the surrounding vertical grid frame columns in one-to-one correspondence. The size of the frame column grid It is equal to the fasting grid, that is, the vertical grid and the horizontal grid form a space grid box structure as a whole, which has the characteristics of a plate. Due to the grid, the nodes of each floor of the structure are smaller than those of the conventional structure shown in Figure 1. The nodes are multiplied, and then conventional on-site casting is labor-intensive, time-consuming, and material-intensive. For this purpose, an integrated industrial process of assembly is adopted. The specific implementation method is as follows:

1) Manufacture of prefabricated parts: the floor and the surrounding grid frame are prefabricated into units, and these units are prefabricated in the prefabrication yard. As shown in Figure 3, the floor is divided into 8 units of A ₁ and 10 units of A ₂ , and the grid frame There are 16 units A and 4 units B on each floor of the standard floor (a total of 4 corners on each floor), as shown in Figure 11. These prefabricated grid concrete units are prefabricated in batches from bottom to top according to the requirements of the construction drawing.

2) The central concrete core tube is poured layer by layer from bottom to top on site, and attention should be paid to the structure of the splicing position of each floor and the floor. A tower crane is installed in the concrete core tube for hoisting and installation of prefabricated units;

3) After the construction of the core tube (2-3 floors), first install the grid A and B units divided in Figure 10, and the prefabricated concrete grid unit A of the wall frame in Figure 11, and the grid frame columns of each layer are on the floor All elevations are prefabricated with short cantilever beams assembled at 45°, where they are spliced with the hollow beams at an angle of 45° to the floor. There should be special mounting brackets for the installation of wall frames to ensure the safe erection of the structure and the secondary pouring of concrete and maintenance. After the surrounding grid frame of each layer is installed in place, the precast concrete hollow grid A ₁ and A ₂ units shown in Figure 3 are installed layer by layer, and Figure 4 is the plan view of the precast concrete grid A ₁ (A ₂ ) unit. The plane area of the covered floor is 35m ² , the self-weight is less than 3T, and the integrity is good. After the tower crane is hoisted in place, there should be a special support frame (which can be lifted) to support in place at each section, as shown in Figure 5. Place four-point supporting steel truss floor slabs at the supports of the hollow floor of the square grid, and only set the formwork at the splicing position. Figure 6 shows the structure of the upper chord node at the shear key position of the prefabricated unit A. The center of the node is the shear key stirrup and Vertical steel bar, the upper end of this steel bar is bent at 90° in the reserved upper chord stirrup. Fig. 7 is the AA section of Fig. 6. At the joint position, the longitudinal bar of the shear key and the upper part of the upper chord are all penetrated into the reserved stirrup. Then place the reinforced truss floor deck at the support positions of the four corners of the grid, and then set the longitudinal reinforcement on the upper chord of the vierendeel beam in the reserved stirrup as shown in Figure 9, and set the vertical reinforcement at the splicing position of the upper and lower chords between units (lower chord) The upper and lower columns, the upper chord is only the lower one) equal strong connection, when the upper and lower chord splicing position formwork is installed, the splicing place and the floor slab are poured with a one-time higher level of concrete, as shown in Figure 9 marked with black fine dots, The sectional structure of the tower floor is formed as shown in Figure 8. The depth of the floor here is 11200, the thickness of the hollow plate is 450 (L/25), and the clearance in the middle is 2.55 m × 0.1 m , which is the interlayer for laying horizontal pipelines. After the splicing position with the horizontal concrete grid is completed, the concrete curing is completed, and the "concrete orthogonal space grid box-type tube-in-tube structure" is formed.

Those skilled in the art should realize that the above-mentioned specific implementation is exemplary only, in order to enable those skilled in the art to better understand the contents of the present invention, and should not be interpreted as limiting the protection scope of the present invention, such as the realization of assembly units For industrialized mass production, the construction unit only needs to start the casting of the central concrete core tube from the second step on site. As long as it is improved according to the technical solution of the present invention, it all falls within the scope of protection of the present invention.

Claims (7)

1. Prefabricated concrete orthogonal space grid box-in-tube structure, characterized in that: the grid of the horizontal fasting floor is equal to the grid of the vertical grid frame, and they are rigidly connected at the intersection; The horizontal hollow floor and the vertical grid frame are unitized and prefabricated, and then installed in layers; The manufacturing method of the prefabricated concrete orthogonal and vertical space grid box-type tube-in-tube structure includes: pouring the central concrete core tube layer by layer from bottom to top on site; A tower crane is installed in the central concrete core tube for hoisting and installation of assembled units; After the construction of 2-3 floors of the central concrete core tube, the surrounding vertical grid frame assembly units are installed first, and the grid frame columns of each layer are prefabricated at 45° assembled cantilever short beams at the elevation of the horizontal vierendeel floor. Here It is spliced with the hollow beam at an angle of 45° to the horizontal hollow floor, and the installation frame is set when the wall frame is installed; After the surrounding grid frame of each layer is installed in place, the concrete hollow grid prefabricated units are installed layer by layer. After the tower crane is hoisted in place, the support frame is set to support in place at each section. 2. The prefabricated concrete orthogonal space grid box-in-tube structure as claimed in claim 1, characterized in that: the horizontal fasting floor and the shear wall around the central concrete core tube are at the position of the horizontal fasting floor Rigid connection. 3. The prefabricated concrete orthogonal space grid box-in-tube structure according to claim 1, characterized in that: the horizontal fasting floor and the central concrete core tube shear wall and the vertical grid frame are respectively Two by two are rigidly connected to form a grid-like box structure. 4. The prefabricated concrete orthogonal and vertical space grid box-in-tube structure according to claim 1, characterized in that: the grid box structure and the central concrete core tube form an orthogonal and positive box-type tube-in-tube structure. 5. The prefabricated concrete orthogonal space grid box-type tube-in-tube structure according to any one of claims 1-4, characterized in that: the manufacturing method includes: Divide the vertical grid frame and the horizontal vierendeel floor into several grid units, and then prefabricate the assembled units, and then install them layer by layer at the construction site. 6. As claimed in claim 5, the prefabricated concrete orthogonal space grid box-type tube-in-tube structure is characterized in that the prefabricated engineering volume accounts for 85% of the total engineering volume. 7. As claimed in claim 1, the prefabricated concrete orthogonal space grid box-in-tube structure is characterized in that: at the node position, the longitudinal reinforcement of the shear key and the upper reinforcement of the upper chord all penetrate into the reserved stirrup, and then The reinforced truss floor deck is placed at the four-corner support positions of the grid, and then the vertical steel bars on the upper chord of the vierendeel beam are set in the reserved stirrups, and the longitudinal steel bars at the splicing positions of the upper and lower chords between the assembled units are connected, as the upper and lower chords After the formwork at the splicing position is installed, the splicing place and the steel truss floor deck are poured with the first-grade concrete at one time, and the concrete hollow grid prefabricated unit and the steel truss floor deck are poured with concrete twice to form a whole horizontal hollow floor. Leave the interlayer for the laying of horizontal pipelines, and when the vertical and horizontal concrete grids are spliced, the concrete curing is completed, that is, the concrete orthogonal space grid box-type tube-in-tube structure is formed.