CN110593897A - Prefabricated hollow concrete segment and prefabricating method - Google Patents

Abstract

The invention relates to a prefabricated hollow concrete segment and a prefabricating method, which are applied to underground engineering constructed by adopting a prefabricating and assembling method, wherein the segment comprises a segment framework, an air bag arranged in the segment framework and used for forming a hollow structure and a segment main body formed by pouring concrete in a layering way, wherein the air bag is arranged along the extension direction of the segment framework and is fixed by a hook on the segment framework.

Description

Prefabricated hollow concrete segment and prefabricating method

Technical Field

The invention relates to the technical field of civil engineering, in particular to a prefabricated hollow concrete segment and a prefabricating method.

Background

Based on the characteristics of good mechanical property and economical efficiency of reinforced (fiber) concrete materials, the tunnel with the prefabricated assembled duct pieces as a bearing structure comprises rail transit, a highway tunnel, a railway tunnel, a municipal pipeline and the like, and the most commonly used duct pieces are reinforced (fiber) concrete duct pieces. Adopt the rib plate formula structure different with the steel-pipe piece, steel (fibre) concrete section of jurisdiction generally is that the entity is whole to water to it is great to cause the section of jurisdiction dead weight, assembles and receives great restriction with the section of jurisdiction size, and then causes section of jurisdiction ring and unit length tunnel section of jurisdiction seam numerous, not only influences the structure atress, moreover because the seam is numerous, has increased the risk of operation in-process tunnel percolating water, consequently the tunnel is assembled and is needed to optimize the improvement with the concrete section of jurisdiction urgently. Meanwhile, concrete cracks generated in the concrete structure construction and operation process can reduce the bearing capacity of the segment structure and influence the durability of the segment structure.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a prefabricated hollow concrete segment and a prefabricating method.

The purpose of the invention can be realized by the following technical scheme:

the utility model provides a prefabricated empty stomach concrete section of jurisdiction, is applied to the underground works who adopts the construction of prefabricated concatenation method, and this section of jurisdiction includes section of jurisdiction skeleton, sets up the gasbag and the fashioned section of jurisdiction main part of layering concreting that are used for forming empty stomach structure in the section of jurisdiction skeleton, the gasbag set up along section of jurisdiction skeleton extending direction to fix through the couple on the section of jurisdiction skeleton.

The duct piece main body is made of steel/fiber reinforced concrete, fiber steel/fiber reinforced concrete or fiber concrete, wherein steel/fiber bars in the steel/fiber reinforced concrete duct piece main body and the fiber steel/fiber reinforced concrete duct piece main body are duct piece stress steel/fiber bars, and steel/fiber bars in the fiber concrete duct piece main body are construction steel/fiber bars for fixing the air bag through a hook.

Prefabricated section of jurisdiction skeleton constitute by many main muscle and ligature many annular stirrups between adjacent main muscle, the gasbag setting in the space that many main muscle and stirrup surround and form.

The fixed position of the air bag avoids the segment embedded part.

The air bag accounts for 20-40% of the volume of the segment, and the distance from the outer surface of the air bag to the outer boundary of the segment meets the requirements of segment stress and the thickness of a steel bar protection layer.

The outer surface of the air bag is streamline, and the material of the air bag is rubber, PVC composite material, waterproof fabric or metal.

The fiber doped in the concrete formed by the cast segment main body adopts steel fiber and synthetic fiber, the steel fiber is carbon steel fiber, low alloy steel fiber or stainless steel fiber, and the synthetic fiber is polyacrylonitrile fiber, polypropylene fiber, polyamide fiber or polyvinyl alcohol fiber.

The duct piece framework material is a steel bar or a fiber bar.

A prefabricating method for prefabricating an open-web concrete segment comprises the following steps:

1) binding a segment framework;

2) placing an uninflated air bag at a set position in the process of binding the segment framework;

3) the air bag hook is accurately positioned, and the air bag is inflated, so that the bearing capacity and the durability of the duct piece cannot be influenced by the implantation of the air bag;

4) adopting commercial concrete to perform hollow concrete segment pouring prefabrication;

5) and (5) demolding, curing and prefabricating the hollow concrete pipe piece.

Compared with the prior art, the invention has the following advantages:

according to the method, the air bag is placed in the concrete pipe to replace solid concrete, so that the prefabricated hollow concrete pipe is obtained, the accurate positioning of the air bag is utilized to ensure that the placing of the air bag does not influence the bearing capacity and durability of a concrete pipe ring, the self weight of the pipe can be reduced, the size of the prefabricated pipe is increased, the convenience of pipe construction is improved, the construction efficiency can be effectively improved, raw materials are saved, the construction cost is saved, the resource loss is reduced, green construction is realized, and the environmental influence is reduced; along with the increase of the load caused by the increase of the tunnel excavation section, the thickness of the segment is also continuously increased, so that the research and development of the hollow concrete segment have important theoretical significance and practical value.

Drawings

Fig. 1 is an elevation view of a prefabricated open-web concrete segment.

Fig. 2 is a cross-sectional view of 1-1 in fig. 1.

Fig. 3 is a cross-sectional view of 2-2 in fig. 1.

Fig. 4 is a cross-sectional view of 3-3 of fig. 1.

Fig. 5 is a cross-sectional view of 4-4 of fig. 1.

Fig. 6 is a cross-sectional view of 5-5 of fig. 1.

Fig. 7 is a cross-sectional view of 6-6 of fig. 1.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.

Examples

The invention provides a prefabricated hollow concrete segment and a prefabricating method, wherein the prefabricated hollow concrete segment can be applied to underground projects constructed by adopting a prefabricating and assembling method, and the prefabricated hollow concrete segment comprises but is not limited to shield tunnels, assembled ring-type pipe-jacking tunnels, prefabricated and assembled secondary linings by a drilling and blasting method, underground pipe galleries, prefabricated and assembled underground projects, underground complexes and the like.

The structure of the prefabricated hollow concrete pipe piece is shown in figures 1-7, the prefabricated hollow concrete pipe piece comprises a pipe piece framework, an air bag arranged in the pipe piece framework and used for forming a hollow structure and a pipe piece main body formed by pouring concrete, and the air bag is fixed through a hook on the pipe piece framework.

The prefabricated hollow concrete segment can be reinforced (fiber) concrete, fiber reinforced (fiber) concrete or fiber concrete, wherein the reinforced (fiber) concrete segment adopts a classic steel (fiber) bar and concrete mechanics calculation mode, the fiber reinforced (fiber) concrete segment considers that the fiber and the steel (fiber) bar are stressed together, the steel (fiber) bar amount configured on the segment can be effectively reduced, and the fiber concrete segment completely adopts the fiber to replace the steel (fiber) bar.

According to the stress characteristics of the segment structure, an air bag is arranged in the segment and is fixed on a segment steel (fiber) rib framework by a hook; wherein the steel (fiber) bars in the reinforced concrete segment and the fiber reinforced (fiber) reinforced concrete segment are segment stress steel (fiber) bars, and the steel (fiber) bars in the fiber reinforced concrete segment are construction steel (fiber) bars for positioning the air bag.

The section of jurisdiction atress and steel bar protection layer thickness requirement are satisfied to the distance that corresponds section of jurisdiction outer boundary in gasbag boundary, the shared section of jurisdiction volume of gasbag reaches 20% ~ 40%, can reduce the concrete volume greatly, the appearance and the location of gasbag should ensure not obviously influencing the section of jurisdiction bearing capacity, and adopt the streamlined of making things convenient for concrete placement, the protective layer thickness of section of jurisdiction reinforcing bar is ensured in the location of gasbag, do not influence the durability of section of jurisdiction structure, the section of jurisdiction inner structure characteristic need be considered in the appearance of gasbag, the built-in fitting that the section of jurisdiction corresponds needs to be dodged.

The air bag material can be rubber, PVC composite material, waterproof fabric, metal or other high polymer materials and the like, has pressure resistance and puncture resistance, avoids rupture and failure in the installation, positioning and concrete pouring processes of the air bag, and has no adverse effect on the environment in the tunnel operation process.

The invention increases the concrete heat dissipation area by the built-in air bag, reduces the volume of the concrete, thereby reducing the segment cracks possibly caused by the hydration heat of the large-volume concrete, and the air bag can obviously reduce the average density of the segments, the segment size can be increased by combining the construction capability of the current tunnel construction mechanical equipment, the number of single-ring and unit-length tunnel segments is reduced, the number of single-ring and unit-length tunnel segment joints is reduced, and the risk of water leakage of the tunnel joints is reduced.

The hook for positioning the air bag has enough strength and toughness, so that the air bag is prevented from deviating in the concrete pouring process, and the segment framework can be made of materials meeting the stress requirements such as reinforcing steel bars and fiber bars.

The fiber doped in the poured concrete can adopt common non-toxic fiber in fiber concrete, such as steel fiber (including carbon steel fiber, low alloy steel fiber, stainless steel fiber and the like) and synthetic fiber (including polyacrylonitrile fiber, polypropylene fiber, polyamide fiber, polyvinyl alcohol fiber and the like), and the fiber doped in the concrete needs to consider the stress requirement besides the control requirement of the segment concrete crack, correspondingly reduces the reinforcement amount of a steel (fiber) rib framework and facilitates the binding of steel (fiber) ribs.

The prefabricating method of the prefabricated hollow concrete segment is realized by the following steps:

(1) binding a segment steel (fiber) rib framework;

(2) an air bag is arranged in the process of binding a segment steel (fiber) rib framework;

(3) the air bag hook is accurately positioned, so that the bearing capacity and the durability of the duct piece cannot be influenced by the implantation of the air bag;

(4) adopting commercial concrete or fiber concrete to perform hollow concrete segment prefabrication;

(5) and (5) demolding, curing and prefabricating the hollow concrete pipe piece.

Claims (9)

1. The utility model provides a prefabricated empty stomach concrete section of jurisdiction, is applied to the underground works who adopts the construction of prefabricated concatenation method, its characterized in that, this section of jurisdiction include section of jurisdiction skeleton, set up the gasbag and the fashioned section of jurisdiction main part of layering concreting that are used for forming empty stomach structure in the section of jurisdiction skeleton, the gasbag along section of jurisdiction skeleton extending direction setting to fix through the couple on the section of jurisdiction skeleton.

2. The prefabricated open-web concrete duct piece of claim 1, wherein the duct piece body material is steel/fiber reinforced concrete, fiber steel/fiber reinforced concrete or fiber concrete, wherein the steel/fiber bars in the steel/fiber reinforced concrete duct piece body and the fiber steel/fiber reinforced concrete duct piece body are duct piece stress steel/fiber bars, and the steel/fiber bars in the fiber concrete duct piece body are construction steel/fiber bars for fixing the air bag through hooks.

3. The precast open-web concrete segment as recited in claim 1, wherein the precast segment frame is composed of a plurality of main ribs and a plurality of annular stirrups bound between the adjacent main ribs, and the air bag is disposed in a space surrounded by the main ribs and the stirrups.

4. The precast open-web concrete segment as recited in claim 3, wherein the fixed position of the air bag is free of segment embedment.

5. The prefabricated open-web concrete segment as claimed in claim 1, wherein the air bag accounts for 20-40% of the volume of the segment, and the distance from the outer surface of the air bag to the outer boundary of the segment meets the requirements of segment stress and the thickness of a steel bar protection layer.

6. The precast open-web concrete segment as recited in claim 1, wherein the outer surface of the air bag is streamlined and made of rubber, PVC composite, impermeable fabric or metal.

7. The precast open-web concrete segment as recited in claim 2, wherein the concrete formed by casting the segment body is doped with steel fibers and synthetic fibers, the steel fibers are carbon steel fibers, low alloy steel fibers or stainless steel fibers, and the synthetic fibers are polyacrylonitrile fibers, polypropylene fibers, polyamide fibers or polyvinyl alcohol fibers.

8. The precast open-web concrete segment as recited in claim 1, wherein the segment skeleton material is steel bars or fiber bars.

9. A prefabrication method for prefabricating a hollow concrete segment is characterized by comprising the following steps:

1) binding a segment framework;

2) placing an uninflated air bag at a set position in the process of binding the segment framework;

3) the air bag hook is accurately positioned, and the air bag is inflated, so that the bearing capacity and the durability of the duct piece cannot be influenced by the implantation of the air bag;

4) adopting commercial concrete to perform hollow concrete segment pouring prefabrication;

5) and (5) demolding, curing and prefabricating the hollow concrete pipe piece.