Large-span reinforced concrete laminated open-web truss

Abstract

The utility model belongs to the technical field of building engineering, specifically discloses a large -span reinforced concrete laminated open web truss, including core tube overhanging support structure, reinforced concrete temporary support system and laminated open web truss system, the core tube overhanging support structure includes the cantilever wall of overhanging from core tube side wall, the cantilever wall top perpendicularly is provided with the stiff concrete column, the stiff concrete column top end is rigidly connected with the lower chord node of laminated open web truss system, the shear wall or super large section column of traditional self bottom slab deck rooting is supported with the open web truss by the cantilever support structure in the core tube from bottom, thereby ensuring the architectural effect of large space, the open web truss construction is supported with the reinforced concrete temporary frame support system, and the compressive resistance is high, the deformation under the combined gravity influence of layer-by-layer loading working condition is small, the engineering cost is reduced, and the engineering construction efficiency is improved.

Description

Technical Field

[0001] This utility model belongs to the field of building engineering technology, and specifically discloses a large-span reinforced concrete laminated hollow truss. Background Technology

[0002] With the development of technology and the updating of architectural concepts, the application of steel truss structures in large-span spatial buildings is becoming increasingly widespread. In large-span buildings, open-web trusses are a common structural form. Design units often only design the stacked open-web truss structure for the service stage after construction. However, during the construction stage, as the number of structural layers increases and the strength and stiffness of each component gradually form during the construction of each layer, the entire stress system will continuously undergo stress redistribution. Therefore, the bottom of the stacked open-web truss needs to be supported during construction until the structural system is formed and reaches the design strength.

[0003] Traditional concrete open-web trusses are supported by shear walls or ultra-large cross-section columns rooted in the foundation slab, resulting in a smaller building space below the open-web truss. For the construction support system of stacked open-web trusses, heavy-duty full-span support frames, Bailey bridges, lattice columns, or steel tube columns are generally used. The disadvantage is that during the loading process of high-clearance stacked open-web trusses, the support system undergoes large vertical deformation under the influence of truss loading and its own weight, making it impossible to effectively control the overall deflection of the open-web truss. If the high-clearance stacked open-web truss is made of reinforced concrete, the use of such supports will inevitably have an impact on structural safety. Utility Model Content

[0004] This utility model proposes a large-span reinforced concrete stacked hollow truss, which replaces the traditional shear wall or ultra-large section column rooted in the bottom slab with a cantilever support structure in the core tube to support the hollow truss, thereby ensuring the architectural effect of large space. The hollow truss construction adopts a reinforced concrete temporary frame support system, which has high compressive strength, small deformation under gravity under layer-by-layer loading conditions, reduces project cost, and improves project construction efficiency.

[0005] This utility model is implemented as follows: a large-span reinforced concrete laminated hollow truss, including a core tube cantilever support structure, a reinforced concrete temporary support system, and a laminated hollow truss system.

[0006] The cantilever support structure of the core tube includes a cantilever wall that cantilevers from the side wall of the core tube. A stiffened concrete column is vertically installed at the top of the cantilever wall, and the top of the stiffened concrete column is rigidly connected to the lower chord node of the laminated hollow truss system.

[0007] The reinforced concrete temporary support system is equipped with a sand box at the top to bear the truss load during the construction phase.

[0008] As a preferred embodiment of the large-span reinforced concrete laminated hollow truss of this utility model, the cantilever wall is a reinforced concrete shear wall with an internal H-shaped steel frame, and the H-shaped steel frame is welded to the main reinforcement of the core tube structure.

[0009] As a preferred embodiment of the large-span reinforced concrete laminated hollow truss of this utility model, the stiffened concrete column has an H-shaped steel core column built inside, the bottom of which is welded to the steel frame in the cantilever wall, and the top is connected to the lower chord of the hollow truss through a steel node plate.

[0010] As a preferred embodiment of the large-span reinforced concrete laminated hollow truss of this utility model, the sand box is a steel container with built-in quartz sand and an adjustable steel pad on the top for graded unloading to control the truss deflection.

[0011] As a preferred embodiment of the large-span reinforced concrete laminated hollow truss of this utility model, the support plate at the top of the sand box is clearance-fitted with the bottom surface of the lower chord of the laminated hollow truss system, and the bottom of the sand box is fixedly connected to the reinforced concrete temporary support system through a flange.

[0012] The beneficial effects of this utility model are:

[0013] 1. The support structure formed by cantilever walls and stiffened concrete columns ensures a large space effect under the open truss.

[0014] 2. By constructing the reinforced concrete temporary support system simultaneously with the substructure, effective integration can be achieved, thus accelerating the construction period.

[0015] 3. When unloading the reinforced concrete temporary support system, sand boxes are used to assist in controlling the unloading displacement in stages to enhance the overall safety and stability.

[0016] 4. The reinforced concrete temporary support system is a one-time investment, avoiding the uncontrollable defects of steel rental cycle and effectively reducing the cost of the measure. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0018] Figure 1 This is a construction schematic diagram of a large-span reinforced concrete laminated hollow truss according to the present invention.

[0019] Figure 2 This is a schematic diagram of the cantilever wall of this utility model.

[0020] Figure 3This utility model Figure 2 Enlarged structural diagram at point A in the middle.

[0021] Figure 4 This is a structural diagram of the reinforced concrete temporary support system of this utility model.

[0022] Figure 5 This is a structural diagram of the present invention after construction is completed.

[0023] The markings in the diagram are: 1. Core tube; 2. Cantilever wall; 3. Stiffened concrete column; 4. Stacked hollow truss system; 5. Sand box; 6. Reinforced concrete temporary support system. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and specific embodiments to aid in understanding its content. Unless otherwise specified, the methods used in this invention are conventional methods; the raw materials and apparatus used, unless otherwise specified, are conventional commercially available products.

[0025] Please see Figure 1-5 A large-span reinforced concrete laminated hollow truss includes a core tube cantilever support structure, a reinforced concrete temporary support system 6, and a laminated hollow truss system 4.

[0026] The cantilever support structure of the core tube includes a cantilever wall 2 that cantilevered from the side wall of the core tube 1. A stiffened concrete column 3 is vertically installed at the top of the cantilever wall 2. The top of the stiffened concrete column 3 is rigidly connected to the lower chord node of the laminated hollow truss system 4.

[0027] A sand box 5 is installed on top of the reinforced concrete temporary support system 6 to bear the truss load during the construction phase.

[0028] In this embodiment: the device is constructed to the cantilever wall 2 on the side wall of the core tube 1. Reinforced concrete columns 3 are anchored on the upper part of the cantilever wall 2. The reinforced concrete temporary support system 6 is constructed simultaneously with the cantilever structure of the core tube, enabling effective integration and accelerating the construction period. After the construction of the core tube cantilever support structure up to the cantilever wall columns and the reinforced concrete temporary support system 6 is completed, the upper layered open-web truss system is constructed. The layered open-web truss system 4 uses a reinforced concrete temporary frame support system, whose main material is reinforced concrete, and its compressive strength... It is far superior to steel structures. Under the condition of layer-by-layer loading, the deformation due to gravity is small. This structure can reduce the project cost, improve the project construction efficiency, and achieve better social and economic benefits. After the entire stacked hollow truss system is formed, the sand box 5 is used for staged unloading. After the deflection deformation of the upper stacked hollow truss system stabilizes, the reinforced concrete temporary support system 6 is removed, thus forming a large-span suspended stacked hollow truss structure system. The use of reinforced concrete temporary support system 6 avoids the defects of uncontrollable steel rental cycle and effectively reduces the cost of measures.

[0029] As a technical optimization of this utility model, the cantilever wall 2 is a reinforced concrete shear wall with an internal H-shaped steel frame, and the H-shaped steel frame is welded to the main reinforcement of the core tube 1.

[0030] In this embodiment: the H-shaped steel frame serves as a "rigid template" and is hoisted and positioned in advance before the reinforcement of the cantilever wall 2 is tied. The flanges are provided with through holes and are connected to the main reinforcement of the core tube 1 by through-hole plug welding (implied process). The web is welded to the stirrups of the hidden columns of the core tube 1 to form a "steel-reinforcement" composite frame. After the concrete is poured, the H-shaped steel frame and the concrete transfer shear force through shear studs (not marked but conventionally set), so that the cantilever wall 2 can bear the construction load (such as the self-weight of the truss template) before the strength is formed, shortening the construction waiting time.

[0031] As a technical optimization of this utility model, the rigid concrete column 3 has an H-shaped steel core column built in, the bottom of which is welded to the steel frame in the cantilever wall 2, and the top is connected to the lower chord of the hollow truss through a steel node plate.

[0032] In this embodiment: the bottom of the H-shaped steel core column of the rigid concrete column 3 is connected to the H-shaped steel frame of the cantilever wall 2 by full penetration groove welding to form an "integrated steel-wall node". The vertical load (such as the self-weight of the truss) is directly transferred to the frame of the cantilever wall 2 through the flange of the core column, and then distributed to the foundation through the main reinforcement of the core tube 1. The top steel node plate is bolted with bolt holes to the steel section of the lower chord of the truss. At the same time, the perimeter is sealed with fillet welds to form a rigid node, which can withstand the tension and bending moment of the lower chord of the truss and avoid the cracking risk of traditional concrete nodes.

[0033] As a technical optimization of this utility model, the sand box 5 is a steel container with built-in quartz sand and an adjustable steel pad on the top for graded unloading to control the truss deflection.

[0034] In this embodiment: the quartz sand (particle size 0.5–2mm) filled in the sand box 5 forms a bulk material support using the friction between sand particles. The bearing capacity is adjusted according to the diameter of the sand box 5. During construction, the lower chord of the truss is lifted by steel pads, so that the sand box 5 bears part of the construction load, reducing the initial stress on the cantilevered core tube structure. During unloading, the quartz sand is gradually released through the sand discharge holes at the bottom of the sand box 5. The flow of sand particles causes the stress gradient inside the sand box 5 to decrease, and the rate of truss load is transferred to the cantilevered core tube structure. After each unloading, the structure is left to stand for 12 hours. The mid-span deformation is monitored using a deflectometer (accuracy 0.01mm) to ensure that the deformation rate is ≤0.5mm / h, avoiding the structural impact caused by traditional one-time unloading. The steel pads achieve elevation control with an accuracy of ±1mm through M20 adjusting bolts (pitch 2mm), which can compensate for concrete shrinkage deformation in real time during the truss pouring process.

[0035] As a technical optimization of this utility model, the support plate at the top of the sand box 5 is fitted with the bottom surface of the lower chord of the laminated hollow truss system 4 with a clearance, and the bottom of the sand box 5 is fixedly connected to the reinforced concrete temporary support system 6 through a flange.

[0036] In this embodiment: a 5-10mm gap is reserved during the construction phase so that the lower chord of the truss is supported only by the stiffened concrete column 3 during pouring, ensuring that the cantilever structure first forms stiffness according to the design conditions (avoiding the temporary support being stressed in advance, which would cause the stress of the cantilever structure to be "short-circuited"). After the truss strength reaches the standard, the gap is eliminated by lifting with steel pads, and the temporary support begins to participate in the stress, realizing the stress sequence of "main body first, then support". The bottom flange of the sand box 5 is connected to the embedded steel plate of the temporary support column by high-strength bolts and welded stiffening ribs are set. This connection method can avoid the high temperature stress of traditional welded connections and is easy to disassemble, improving construction efficiency.

[0037] The gap between the support plate and the bottom surface of the lower chord is filled with elastic sealant after unloading to prevent rainwater from seeping into the sand box 5; the flange connection is treated with anti-corrosion (epoxy zinc-rich primer + polyurethane topcoat).

[0038] The working principle and usage process of this utility model are as follows: The device is constructed to the cantilever wall 2 that is cantilevered on the side wall of the core tube 1. A rigid concrete column 3 is anchored on the upper part of the cantilever wall 2. The cantilever wall 2 serves as a permanent support foundation. Its built-in H-shaped steel frame is welded to the main reinforcement of the core tube 1 to form a rigid connection node, ensuring that the cantilever end has initial anti-overturning stiffness. The H-shaped steel core column of the rigid concrete column 3 at the top of the cantilever wall 2 is welded to the steel frame of the cantilever wall 2 to form a "steel-concrete" combined force system, providing a support interface for subsequent truss installation.

[0039] The reinforced concrete temporary support system 6 is constructed simultaneously with the cantilevered core tube structure. After the cantilevered core tube support structure is completed and the cantilevered wall columns and the reinforced concrete temporary support system 6 are also completed, the upper layered hollow truss system 4 is constructed. After the entire layered hollow truss system 4 is formed, the sand box 5 is used for staged unloading. After the deflection deformation of the upper layered hollow truss system 4 stabilizes, the reinforced concrete temporary support system 6 is dismantled, thus forming a large-span suspended layered hollow truss structure system.

[0040] In the description of this utility model, it should be understood that the terms "left", "right", "up", "down", "top", "bottom", "front", "back", "inner", "outer", "back", "middle", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0041] However, the above description is only a specific embodiment of this utility model and should not be construed as limiting the scope of implementation of this utility model. Therefore, any substitution of equivalent components or equivalent changes and modifications made in accordance with the scope of protection of this utility model should still fall within the scope of the claims of this utility model.

Claims

1. A large-span reinforced concrete laminated open-web truss, characterized in that: It includes a cantilevered core tube support structure, a reinforced concrete temporary support system (6), and a stacked open-web truss system (4); The cantilever support structure of the core tube includes a cantilever wall (2) cantilevered from the side wall of the core tube (1), and a stiffened concrete column (3) is vertically installed at the top of the cantilever wall (2). The top of the stiffened concrete column (3) is rigidly connected to the lower chord node of the stacked hollow truss system (4). The reinforced concrete temporary support system (6) is equipped with a sand box (5) on top to bear the truss load during the construction phase.

2. A large-span reinforced concrete laminated open-web truss according to claim 1, characterized in that: The cantilever wall (2) is a reinforced concrete shear wall with an internal H-shaped steel frame, and the H-shaped steel frame is welded to the main reinforcement of the core tube (1).

3. A large-span reinforced concrete laminated open-web truss according to claim 1, characterized in that: The rigid concrete column (3) has an H-shaped steel core column inside, the bottom of which is welded to the steel frame inside the cantilever wall (2), and the top is connected to the lower chord of the hollow truss through a steel node plate.

4. A large-span reinforced concrete laminated open-web truss according to claim 1, characterized in that: The sand box (5) is a steel container with built-in quartz sand and an adjustable steel pad on top for graded unloading to control truss deflection.

5. A large-span reinforced concrete laminated open-web truss according to claim 1, characterized in that: The support plate at the top of the sand box (5) is fitted with the bottom surface of the lower chord of the laminated hollow truss system (4) with a clearance, and the bottom of the sand box (5) is fixedly connected to the reinforced concrete temporary support system (6) through a flange.

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