CN107143124B - A kind of super pressure scaffolding steel pipe - Google Patents

Abstract

The invention discloses an overpressure scaffold steel pipe that exceeds the traditional slenderness ratio and can withstand greater axial pressure. It includes a round pipe rod, a grouting chamber and a prestressed kit, wherein the circular pipe rod is arranged in parallel. There is a backing plate. The adjacent backing plate and the inner wall of the circular tube rod form the grouting chamber. The grouting chamber is filled with grouting material. The prestressed set is arranged on the inner wall of the circular tube rod. port, and one end of the prestressed set extending into the circular tube rod is in contact with the backing plate. Set up a grouting chamber inside the round tube member, pour high-strength mortar into it, and set a prestressed kit on at least one port of the round tube member. After the grouting material reaches the strength, tighten the bolts at the end, so that the round tube member can A certain amount of prestress is generated on the outer wall, and the rods treated in this way can have a pressure-bearing capacity several times greater than that of traditional rods.

Description

A kind of super pressure scaffolding steel pipe

Technical field

The invention relates to the field of scaffolding engineering in the technical fields of construction and civil engineering, and is specifically an overpressure scaffold steel pipe, an overpressure rod that can withstand greater axial force.

Background technique

The diameter of traditional commonly used scaffolding steel pipes is usually 48mm, and the wall thickness is usually 3.0mm-4.0mm. Since the erection of scaffolding requires almost no machinery and requires a lot of labor during installation, the weight of a single scaffolding steel pipe must be suitable for individual operation. The lighter the scaffolding steel pipe is, the easier it is to operate.

Traditional scaffolding steel pipes (taking 48*3.5 as an example) are limited by the slenderness ratio. According to Euler's critical force calculation, P _crb =π ² EI/L ² , (where, P _crb : critical bearing capacity of the rod; E: elasticity Modulus; I: moment of inertia; L: rod), for a riser with a height of three meters, the ultimate bearing capacity without lateral support is about 2.4 tons. In actual use, in order to increase the vertical bearing capacity of the vertical pole, a horizontal pole is usually installed every 1.2 meters. However, this not only greatly increases the use of crossbars, but also adds a lot of difficulties to the passage of people inside the rack and the transportation of items.

At present, the upper limit of the bearing capacity of existing scaffolding steel pipes is the Euler critical force. To increase the pressure bearing capacity, it is usually necessary to increase the cross-section to solve the stability problem, resulting in the use of more steel and the bulky appearance of the scaffolding steel pipes.

Contents of the invention

The purpose of the present invention is to provide an overpressure scaffold steel pipe that exceeds the traditional slenderness ratio, can withstand greater axial force, and breaks through the Euler critical stress. It also has the characteristics of saving materials, being lighter, and having a simple principle. , easy to make, the cost of steel pipes is greatly reduced compared to traditional scaffolding, and the erection workload is halved, making it more convenient to work in the scaffolding.

In order to achieve the above object, the present invention proposes an overpressure scaffolding steel pipe, which includes a round pipe rod, a grouting chamber and a prestressed kit, wherein the circular pipe rod is provided with pads in parallel, and the adjacent pads are The plate and the inner wall of the circular tube rod form the grouting chamber, the grouting chamber is filled with grouting material, the prestressed set is arranged at the port of the round tube rod, and the prestressed set extends One end inside the circular tube rod comes into contact with the backing plate.

Further, in the over-pressure scaffolding steel pipe, the prestressed kit includes an end plate and connecting bolts, wherein the end plate is fixed on the port of the circular tube rod, and the end plate extends along the circle. A connecting bolt hole is opened in the axial direction of the pipe rod, and the connecting bolt penetrates the connecting bolt hole and contacts the backing plate.

Further, in the overpressure scaffolding steel pipe, the prestressed kit includes internal threads and bolts with internal hexagonal grooves opened on the inner wall of the port of the round pipe rod, and the bolts with internal hexagonal grooves are The external thread matches the internal thread on the inner wall of the port of the round tube rod, and one end of the bolt with an internal hexagonal groove away from the port of the round tube rod contacts the backing plate.

Further, in the overpressure scaffolding steel pipe, the pad is a hemispherical pad.

Further, in the overpressure scaffolding steel pipe, the grouting material is high-strength mortar.

Further, in the overpressure scaffolding steel pipe, the round pipe rod is a hollow long rod.

Further, in the overpressure scaffolding steel pipe, a liner is provided on the inner wall of the circular pipe rod.

Further, in the overpressure scaffolding steel pipe, the lining pipe is one of a water glass lining pipe or a plastic corrugated pipe.

Compared with the existing technology, the main innovation points of this invention are:

1. Taking advantage of the good pressure resistance of high-strength mortar, use high-strength mortar as the filling material in the grouting chamber of the over-pressure scaffolding steel pipe to withstand pressure. The tensile capacity of the overpressure scaffolding steel pipe matches the compression capacity of the mortar.

2. When filling the mortar, first line the overpressure scaffolding steel pipe with a layer of water glass liner or plastic corrugated pipe, so that the high-strength mortar and the inner wall of the overpressure scaffolding steel pipe are infinitely close and can be misaligned with each other.

3. As a standard scaffolding tube, the weight per meter is effectively controlled, making it easier for workers to operate.

4. The overpressure scaffolding steel pipe port is equipped with a prestressed kit, and high-strength bolts are used to push back to provide pretension to the outer pipe of the overpressure scaffolding steel pipe.

5. The cost of the overpressure scaffolding steel pipe proposed by the present invention is close to the lowest and has good economic efficiency.

Description of drawings

Figure 1 is a schematic structural diagram of scheme 1 of the overpressure scaffolding steel pipe prestressed kit of the present invention;

Figure 2 is a schematic structural diagram of the first prestressed kit solution;

Figure 3 is a schematic structural diagram of scheme 2 of the overpressure scaffolding steel pipe prestressed kit of the present invention;

Figure 4 is a schematic structural diagram of the first prestressed kit solution.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

As mentioned in the background art, the upper limit of the load-bearing capacity of scaffold steel pipes in the prior art is the Euler critical force. Without adding additional steel materials, the pressure-bearing capacity of the scaffold steel pipe cannot be improved, that is, the Euler critical force cannot be exceeded. . In view of this, the inventor concluded through research and theoretical derivation that injecting high-strength mortar grouting material into the traditional scaffold steel pipe to obtain a scaffold steel pipe can greatly improve the critical bearing capacity of the scaffold steel pipe.

The critical force of an ordinary Euler rod under pressure is

Among them, P _crb : critical bearing capacity of the member; E: elastic modulus; I: moment of inertia; L: member;

However, materials with high yield strength can directly increase the critical bearing capacity. Pressure critical force Ncr:

Among them, A _b : the area of the filling rod; fy: the material yield strength; P _crb : the critical bearing capacity of the rod.

Therefore, the inventor proposed to inject high-yield strength materials such as high-strength mortar and other grouting materials into the scaffolding steel pipe to obtain an overpressure scaffolding steel pipe that breaks through the Euler critical force, making the overpressure scaffolding steel pipe with the same shape, material, and boundary conditions the same as the superpressure scaffolding steel pipe. Compared with traditional Euler rods (scaffolding steel pipes whose upper limit of bearing capacity is Euler's critical force), the critical pressure force can be greatly increased. The bearing method of the overpressure scaffold steel pipe of the present invention can increase the critical force it can bear to about 3 times (the increase in the critical force that can be carried is related to the material of the grouting material, etc.).

Based on the above, this application proposes an overpressure scaffolding steel pipe that exceeds the traditional slenderness ratio and can withstand greater axial force. It also has the characteristics of saving materials and being lighter.

Specifically, as shown in Figures 1 to 4, the present invention proposes an overpressure scaffold steel pipe, which includes a round tube rod 1 body, and the round tube rod 1 is a hollow elongated rod. A backing plate 3 is provided in the parallel tube cross section within the tube of the round tube rod 1 . Preferably, the pads 3 are disposed in both ends of the round tube rod 1 and close to the pipe port of the round tube rod 1. The two adjacent pads 3 and the inner wall of the round tube rod 1 together form a grouting chamber 2. The grouting chamber 2 is filled with grouting materials such as high-strength mortar. The high-strength mortar is a bonding material used for building masonry in buildings. It is synthesized by adding water to a certain proportion of sand and cementing materials (cement, lime plaster, clay, etc.) and belongs to the existing Technology, preferably but not limited to self-compacting high-strength mortar (such as a self-compacting high-strength mortar disclosed in Chinese Patent 200610027202.0), high-strength polymer mortar (such as brand: RJ-55, manufacturer: Beijing Rongdaxin New Technology Co., Ltd.) , high-strength epoxy mortar (such as brand: RJ-H90, manufacturer: Beijing Rongdaxin New Technology Co., Ltd.), etc. In order to make the high-strength mortar and the inner wall of the round pipe rod 1 infinitely close when filling the high-strength mortar, a liner (not shown) is pre-set on the inner wall of the round pipe rod 1. The liner can be a water glass liner or a liner. Small plastic bellows.

In order to improve the pressure-bearing capacity of traditional scaffolding steel pipes, in addition to pouring high-strength mortar in the round pipe member 1 to improve the pressure-bearing capacity, further, a prestressed kit is set at the port of the round pipe member 1 and the prestressed kit is tightened. By applying self-balancing prestress in equal and opposite directions to the round tube member 1 and the core 2 (the grouting chamber filled with high-strength mortar to achieve strength), the round tube member 1 and the core 2 are assembled into a self-prestressed super long The casing column has a finer ratio, thereby improving the rigidity and stability of the structure, adjusting its dynamic performance, and greatly improving the pressure bearing capacity of the overpressure scaffold steel pipe proposed by the present invention.

The structure of the above-mentioned prestressed kit can adopt either of the following two options:

As shown in Figures 1 and 2, the prestressed kit structure scheme 1: the prestressed kit includes an end plate 4 fixed on the port of the round tube member 1, and a hole is opened on the end plate 4 along the axial direction of the round tube member 1 Connecting bolt hole 9, a connecting bolt 5 penetrates the connecting bolt hole 9 and contacts the backing plate 3 located in the circular tube rod 1. When the high-strength mortar poured into the grouting chamber 2 reaches its strength, tighten the connecting bolts 5 on the prestressed kit to apply force on the circular tube member 1 and the core 2 (the grouting chamber filled with the high-strength mortar to reach its strength). Self-balancing prestressing in equal and opposite directions assembles the circular tube rod 1 and the core 2 into a self-prestressed super-large slenderness ratio casing column, which greatly improves the pressure bearing capacity of the overpressure scaffold steel pipe proposed by the present invention.

As shown in Figures 3 and 4, the second structural option of the prestressed kit: the prestressed kit includes an internal thread 6 opened along the circumferential direction of the inner wall of the port 1 of the circular pipe rod, and a hexagonal groove matching the internal thread 6. 8, the bolt 7 is tightened with the help of the hexagonal groove 8. The bolt 7 with the hexagonal groove is in close contact with the backing plate 3 located in the round pipe rod 1, so that the bolt with the hexagonal groove can be passed 7 Apply "prestress" to the round tube rod 1 and the grouting chamber 2 filled with high-strength mortar, thereby improving the pressure-bearing capacity of the round tube rod 1. In this solution, the pad 3 is preferably a hemispherical pad.

It is worth noting that a prestressed kit is provided on at least one port of the round tube member 1, that is, one end of the two ports of the round tube member 1 can be sealed and the other end can be provided with a prestressed kit, or both ports of the round tube member 1 can be provided with a prestressed set. Prestressed kit, and the prestressed kit structure at the two ends of the circular tube member 1 can adopt any one of the above two prestressed kit structure options 1 and 2 as needed.

To sum up, in the overpressure scaffolding steel pipe provided by the embodiment of the present invention, a grouting chamber is set inside the round pipe rod, and high-strength mortar is poured into it, and a prestressed kit is set at at least one port of the round pipe rod, and the grouting material After the strength is reached, tighten the bolts at the end, thereby generating a certain amount of prestress on the outer wall of the round tube rod. The rod after such treatment can have a pressure-bearing capacity several times greater than that of traditional rods.

Although the embodiments of the present invention have been shown and described above, those of ordinary skill in the art will understand that various changes, modifications, and modifications can be made to these embodiments without departing from the principles and spirit of the present invention. Alterations and modifications, the scope of the invention is defined by the appended claims and their equivalents.

Claims (4)

1. An overpressure scaffolding steel pipe, characterized in that it includes a round tube rod, a grouting chamber and a prestressed kit, wherein a plurality of pads are arranged in parallel inside the round tube pole, adjacent to the pads The grouting chamber is enclosed with the inner wall of the round tube rod, and grouting material is poured into the grouting chamber. The prestressed set is arranged at the port of the round tube pole, and the prestressed set extends to One end of the circular tube rod is in contact with the backing plate; The prestressed kit includes an end plate and connecting bolts, wherein the end plate is fixed on the port of the circular tube rod, and the end plate has connecting bolt holes along the axial direction of the circular tube rod, The connecting bolt penetrates the connecting bolt hole and contacts the backing plate; Or the prestressed kit includes internal threads and bolts with internal hexagonal grooves opened on the inner wall of the port of the circular pipe rod, and the external threads of the bolts with internal hexagonal grooves are in contact with the inner wall of the port of the circular pipe rod. Match the internal threads on the bolt, and the end of the bolt with the internal hexagonal groove away from the port of the circular tube rod is in contact with the backing plate; The grouting material is high-strength mortar; A liner is provided on the inner wall of the circular tube rod. 2. The overpressure scaffold steel pipe according to claim 1, characterized in that the pad is a hemispherical pad. 3. The overpressure scaffold steel pipe according to claim 1, characterized in that the round pipe rod is a hollow long rod. 4. The overpressure scaffold steel pipe according to claim 1, characterized in that the liner is a water glass liner or a plastic corrugated pipe.