JP2023036518A - Construction method for ultra-long pre-stressed steel bundle - Google Patents

Abstract

To solve the problem that although a large part of a pre-stressed steel twist yarn in an existing construction method is provided in a vertical surface and a bottom surface, an artificial beam is usually adopted, a maximum length of the artificial beam is generally within 70 m, it is a large technique difficulty how to save time and labor and realize ultra-long pre-stressed bundle, tension, slurry and anchor sealing for an ultra-long pre-stressed steel bundle having a top face thin layer structure.SOLUTION: A construction method for an ultra-long pre-stressed steel bundle includes the steps of: positioning and assembling a pre-stressed tube; inserting an upper face pre-stressed steel bundle; pre-stressing and tensing the upper face; mortar-pressing an upper face pre-stressed bundle tube; and pre-stressing and anchor-embedding the upper face. Mechanical means can be adopted in place of artificial means. Power is provided by an insertion machine, a steel drawn line is penetrated, and efficiency is improved.SELECTED DRAWING: Figure 1

Description

The present invention relates to the construction field of bridge construction, and in particular to a method for construction of ultra-long prestressed steel bundles.

To ensure the safety and stability of large-span concrete structures, it is common to adopt prestressed concrete construction technology. For pipeline burying, cable penetration, tensioning, slurry heading and anchor sealing in prestressed concrete construction technology, it is a whole process that goes through the whole prestressed construction.

Most of the prestressed steel strands in the existing construction methods are placed on the vertical and bottom surfaces, and usually adopt artificial beams, and the maximum length of the artificial beams is generally within 70m. However, how to save time and labor to ensure the realization of ultra-long prestressed bundles, tension, slurry, and anchor sealing for the super-long prestressed steel bundles with thin top layer structure is a big technical difficulty. . On the top surface of the thin layer structure, the operation space is limited due to the manufacturing limit of the box beam top plate, and it takes time to manually operate it. Segment traction method is often used, which opens a traction hole in the bellows, creating a hidden danger in quality.

At present, the prestressing bundling machine is applied to the construction of ultra-long prestressed bundles, but in the process of threading the bundles, only one drive can be realized, and the steel bundles of multi-pair steel strands can only be operated repeatedly. can't In the process of passing the bundle, especially the last few steel strands, it is easy to collide with the pipe wall.
At the same time, the subsequent slurry heading and anchor sealing of prestressing is also difficult due to space limitations. Therefore, the prior art takes a long time to pass the super-long prestressed bundle, and it is difficult to guarantee the prestressed construction quality.

In addition, when constructing conventional large-span continuous beams, the maximum vertical prestressed steel bundle on the top surface is 200 m.
In Hakomuro, the interior space was limited by diaphragm beams. How to achieve bundling, tensioning, slurry crimping and anchor sealing of the top steel strand in a limited space is a technical problem to be solved.

There are currently no effective solutions to problems in the related art.

In view of the problems in the related art, the present invention proposes a construction method for ultra-long prestressed steel bundles to overcome the above-mentioned technical problems existing in the prior art.
Therefore, the specific technical solutions adopted by the present invention are as follows.

The construction method of ultra-long prestressed steel bundles is
positioning and assembling the prestress conduit 18;
inserting a top prestressed steel bundle;
tensioning the upper surface prestress;
mortar pressing the top prestress flux duct 18;
and embedding a top surface prestress anchor.
Preferably, the positioning and assembling of the prestress conduit 18 comprises:
forming a longitudinal prestress hole with a corrugated tube of plastic material;
alternately operating pipe assembly, steel bar restraint, and module assembly;
a step of reliably soldering with a well-shaped positioning steel bar and a steel bar;
inspecting for ruptures in the ripple tube to prevent blockage of the conduit due to mortar leaks in the ripple tube;
and c. preventing solidification of concrete in the tube by pulling on the bushing.
Preferably, the step of inserting said top surface prestressed steel bundle comprises:
By preparing an oblique preliminary hole on the extension line corresponding to the position of the construction hole, the tension rope 9
a step of combining
and d.
Preferably, the pull rope 9 uses a single steel wire and is mechanically threaded by a threader.
Preferably, the step of inserting said top surface prestressed steel bundle comprises:
a step of braiding a steel wire with a deviation of the steel drawn wire and processing the end of the steel bundle;
With the deep-buried anchor technology, the anchor receiving plate 11 is embedded in the groove inside the structure at a distance of 0.2 m from the outer circumference of the structure, and an extension cylinder is inserted between the anchor receiving plate 11 and the tensioning oil cap 17 during tensioning. placing and translating;
A reeving hole path is prepared at the front end of the tooth block, and the steel drawing wire of the entire bundle is drawn manually by assisting the machine. , cutting the steel wire with the wheel.
Preferably, the steps of forming a misaligned steel wire of the drawn steel wire and treating the end of the steel bundle include:
forming a cone at the front end by offset knitting from a steel wire;
forming a conical shape by conically weaving one end of the tension rope with a fine steel wire and a steel draw wire through which the entire bundle should be inserted;
cutting the steel draw wire in the unwoven portion after threading with the wheel.
Preferably, said top surface prestressing step comprises:
Preparing two oil cap spare eyelets on the beam face, passing steel wire cables through it, and installing a chain hoist with a lifting means upside down on the beam face;
lifting the taut oil cap 17 in the beam by means of a chain hoist on top of the beam and mounting a control platform or an inspection truck in the beam;
Attaching stop plates, anchors, clip transition rings, and completing the tensioning.
Preferably, the step of mortar pressing the top prestress flux duct 18 comprises:
a step of performing mortar pressing within 48 hours after tension construction;
cutting the exposed steel wire and embedding the anchor;
and arranging the mortar injection holes on the anchor receiving plate 11 .
Preferably, the method of mortar pressing comprises:
vacuum extraction, starting the vacuum pump to make the system negative pressure 0.07~0.1Mpa;
Stop the pump for 1 minute when the degree of vacuum in the tunnel becomes constant,
If the pressure drop is less than 0.02Mpa, it is determined that the hole is vacuum, and the pressure drop is 0.0
If greater than 2Mpa, determine that the hole passage is not fully sealed and needs inspection and correction before mortar injection.
Preferably, the top surface prestress anchor embedding step comprises:
fixing the taut end anchor embedding module 22 directly from the top surface to the top surface of the beam by iron wire to reduce the problem of narrow operating space;
installing a preliminary hole 15 in the upper surface of the deep-buried anchor mouth;
and pouring anchor-embedded concrete from the upper surface of the beam and shaking.

According to the above technical solution of the present invention, using the construction method of "pull + prepare + stretch", there are space restrictions and labor in constructing the upper surface ultra-long prestress steel bundle, and the hole wall by the steel drawn wire It solves the problems of easy destruction of the mortar, lack of mortar press, and difficulty of embedding anchors.
Moreover, it has the following technical effects.
1 Mechanical means may be employed in place of manual labor. The insertion machine provides power to realize the penetration of the steel drawing wire and improve the efficiency.
2 Make it "discrete → whole". By using a tension rope as a guide, it is possible to align the prestress bundle through the whole hole, and solve the problem that the cycle is long if repeated insertion work is performed using a single steel drawn wire. In addition, the full hole penetration can ensure the relative forward direction and relaxation between the steel drawn wires.
3 Prepare a reeving hole path in the beam plane. Both the steel draw wire and the threader are placed in the plane of the beam. The entire threading process basically takes place in the plane of the beam. Therefore, it is possible to effectively avoid adverse effects due to the limitation of the lower space.
4 The prestress connection end can be made into a conical end by steel wire slip knitting. It also has a protective cover on the front end, which effectively isolates the steel bundle and the hole wall.
To prevent stress concentration on an anchor receiving plate by adjusting the displacement of an anchor tool using a hole opening. The deep-buried anchor groove design simplifies the operation of embedding the anchor and guarantees the construction weight.
6. The application of this construction technology is highly efficient, rapid, and prestressed under the limited indoor space.
We have achieved the completion of high-quality prestressed construction, and this technology can be expanded horizontally.
It is applied to the construction of prestressed structures without construction conditions below, such as steel mixed beams, and has a wide range of applications.

In order to describe the embodiments of the present invention or the technical aspects in the prior art more clearly, the following briefly introduces the drawings that need to be used in the embodiments. Obviously, the drawings in the following description are just some embodiments of the present invention, and those skilled in the art can also derive other drawings based on these drawings without creative effort.

1 is a flow chart of a method for constructing an ultra-long prestressed steel bundle according to an embodiment of the present invention; FIG. 4 is a layout diagram of a box beam upper surface prestress according to an embodiment of the present invention; FIG. 4 is a schematic diagram showing a tension rope penetration according to an embodiment of the present invention; 1 is a schematic diagram showing prestressed steel bundle knitting according to an embodiment of the present invention; FIG. 1 is a schematic diagram showing a deep-buried anchor according to an embodiment of the present invention; FIG. FIG. 3 is a schematic diagram showing tension reeving according to an embodiment of the present invention; FIG. 4 is a schematic diagram showing upper surface tension according to an embodiment of the present invention; FIG. 3 is a schematic diagram showing anchor embedding according to an embodiment of the present invention;

[Description of symbols]
1 Box beam upper plate 2 Prestressed steel bundle 3 Anchor fixing tooth block 4 Tension oil cap 5 Diaphragm beam 6 Box beam bottom plate 7 Insertion machine 8 Preliminary hole path 9 Pulling rope 10 Hole path center line 11 Anchor receiving plate 12 Large anchor preliminary hole 13 Chain hoist 14 Suspension frame 15 Spare hole 16 Steel wire cable 17 Tensioning oil cap 18 Prestress pipe 19 Transition ring 20 Concrete injection hole 21 Beam body 22 Anchor embedding module 23 Anchor embedding concrete 24 Pipe center line

In order to further describe each embodiment, the drawings are part of the disclosure of the present invention and are mainly used to describe the embodiments, and together with related descriptions in the specification, explain the principle of operation of the embodiments. and, upon reference to these contents, those skilled in the art should be able to appreciate other possible embodiments and advantages of the present invention, the components in the figures being drawn in proportion. do not have. Similar component codes are commonly used to represent similar components.

The present invention provides a method for constructing ultra-long prestressed steel bundles.
The main steps of this construction method include pipe positioning and assembly, insertion of top prestressed steel bundle 2, top prestress tensioning, pipe mortar press into top prestress bundle, top prestress anchor embedding, and so on. Optimization and innovation are made to the overall construction procedure of the top prestressed steel bundle 2 . "Pulling (piercing the entire hole by mechanical movement of the pulling rope) + preparation (reeving,
Tensioning, use of spare holes in mortar press) + Tensioning (increased tension at the end of tensioning, embedding anchors in grooves) effectively improves work efficiency and eliminates limitations due to spatial inconvenience in top surface prestress construction. reduce and smooth the overall procedure construction of the upper surface steel bundle.
The main ideas of this method are: (1) "pulling": increasing the effect by "manually but mechanically completing the penetration of the pulling rope into the entire hole", (2) " Preparedness: Comprehensive consideration in top surface prestress construction, that is, comprehensive consideration of the number of preliminary hole positions, accuracy, and operability, reeving, tensioning, mortar pressing, and anchor embedding in each process (3) "Tensioning": tensioning of the upper surface ultra-long rope, limitation of the upper surface space in the process of embedding the anchor, positioning and anchoring of the end module,
Considering factors such as concrete pouring, it includes devising ways to avoid "edge failure" and improve construction quality.

The present invention will be described with reference to the drawings and examples. FIG. 1 shows a method of constructing an ultra-long prestressed steel bundle according to an embodiment of the present application. The method includes the following steps.
S1: Positioning and assembly of the prestress conduit 18;
Step S1 includes the following steps.
S11: Formation of longitudinal prestress holes with plastic corrugated tubes.
S12: Alternate operation of pipe assembly, steel bar restraint and module assembly.
S13: Reliably soldering with the U-shaped positioning steel bar and the steel bar.
In addition, according to the principle of one path for each 1m straight step and one path for each 0.5m curved step, in the process of arranging the pre-stress rippled pipe, it is possible to ensure the accuracy and reliability of the positioning of the hole and the prevention of floating and lateral bending. .
S14: Check for rupture in the rippled tube to prevent clogging of the rippled tube due to mortar leak.
S15: Prevent solidification of concrete in the pipe by pulling and pushing the cannula.

S2: Insertion of top prestressed steel bundle.
As shown in FIGS. 2-3, step S2 includes the following steps.
S21: Assemble the pulling rope 9 by preparing oblique spare holes on the extension line corresponding to the position of the construction hole (it can be operated by two people, greatly reducing labor intensity and improving production efficiency).
The pulling rope 9 is made of a single drawn steel wire and is mechanically inserted by a threading machine. Since one steel drawn wire has a smaller volume than the hole, the steel drawn wire can be easily installed through.
S22: Pierce the prestressed steel bundle 2 through the entire hole.
As shown in FIGS. 4-6, step S22 includes the following steps.
S221: Displaced steel wire knitting of steel drawn wire and end treatment of steel bundle.
Step S221 includes the following steps.
S2211: A cone is formed at the front end by slip knitting from a steel drawing wire.
S2211: A conical shape is formed by weaving one end of the tension rope and the steel draw wire through which the entire bundle should be inserted by a fine steel wire into a conical shape.
S2211: After inserting, cut off the drawn steel wire in the non-knitted portion with the wheel.
S222: With the deep-buried anchor technology, the anchor receiving plate 11 is 0.2m from the configuration outer edge line.
embedded in the recessed groove inside the distance structure (the open design reduces the friction between the pipe and the entire steel bundle), and an extension tube is inserted between the anchor receiving plate 11 and the tensioning oil cap 17 during tensioning. By installing and displacing the anchor, the gap between the displacement ring and the groove wall adjusts the positional deviation of the anchor, thereby ensuring that the anchor is positioned in the recessed groove of the anchor receiving plate 11, and stress concentration is reduced. To prevent.
S223: A reeving hole path is prepared at the front end of the tooth block, and the steel drawing wire of the entire bundle is manually drawn with the aid of the machine. The remaining steel wire is cut by the wheel.
In addition, both the steel drawing wire and the inserter are arranged in the beam plane. The insertion process is almost completed in the plane of the beam, effectively avoiding the influence of the lower space limitation.

S3: top surface prestress tension.
As shown in FIG. 7, step S3 includes the following steps.
S31: Prepare two oil cap spare holes on the beam surface, pass the steel wire cable through it, and install the chain hoist with the lifting means upside down on the beam surface.
S32: Lift the tension oil cap 17 in the beam with the chain hoist on the upper surface of the beam, place the operation table in the beam, or install the inspection truck (using double control during the tensioning process, mainly to control the tension stress). and use it to check the amount of tension extension).
S33: Install stop plate, anchoring device, clamping piece displacement ring, and complete tension work.
This makes it possible to ensure a smooth tensioning of the top-prestressed steel bundle during the tensioning process. The tension oil cap 17 can be passed through the end steel draw wire and perpendicular to the cross-section of the tension steel draw wire.

S4: Mortar pressing of the top prestress bundle duct 18 .
Step S4 includes the following steps.
S41: Mortar press is performed within 48 hours after tension construction.
The method of the mortar press is as follows.
S411: Vacuum extraction. Start the vacuum pump and set the system negative pressure to 0.07 to 0.1Mp
Let a.
S412: When the degree of vacuum in the tunnel becomes constant, the pump is stopped for 1 minute.
S413: If the pressure drop is less than 0.02Mpa, it is determined that the hole passage is vacuum; if the pressure drop is greater than 0.02Mpa, the hole passage is not completely sealed and needs to be inspected and corrected before mortar injection. Determine that there is.
S42: Cut off the exposed steel wire and embed the anchor.
S43: Arrange the mortar injection holes on the anchor receiving plate 11 .

S5: Top surface prestress anchor embedding.
As shown in FIG. 8, step S5 includes the following steps.
S51: The tension end anchor embedding module 22 is directly fixed on the upper surface of the beam by iron wire from the upper surface to reduce the problem of narrow operation space.
S52: Install a preliminary hole 15 on the upper surface of the deep-buried anchor port.
S53: Anchor-embedded concrete is injected from the upper surface of the beam and shaken tightly.
After the upper surface prestress tensioning is completed, the operation space at the site becomes narrow, and it becomes impossible to assemble the module and fix the module. Guarantee.

In order to facilitate the understanding of the above-mentioned scheme of the present invention, the working principle and operation method in the actual implementation process of the present invention will be described in detail below.
In practical application, first, when the insertion conditions are satisfied, the tension rope 9 is assembled by the insertion machine 7 on the upper surface of the beam using the preliminary hole 15 . Since the pulling rope 9 uses a single steel drawn wire, it has a certain hardness, and the single steel drawn wire has a smaller volume than the spare conduit, so that it can be easily inserted. Before the formal penetration, the penetration amount is determined according to the length of the pipeline and the preparatory length. All the inserted steel wires of the steel bundle are knitted together by a net bag along the cone. By connecting the front end and the tension rope to pull it by the machine and pull it in the opposite direction, it is possible to pull the steel drawn wire of the whole hole to a predetermined position at once. This solves the problems of smooth insertion of steel drawn wire, artificial low efficiency, and long cycle due to repeated insertion of single steel drawn wire. In addition, the full hole penetration can ensure the relative forward direction and relaxation between the steel drawn wires. Furthermore, since the pipe is prevented from being clogged by the collision of the steel bundle with the hole wall in the pipe, smooth insertion of the steel bundle can be ensured. At the end of the steel bundle of the inserted whole bundle, a steel wire net is knitted into a conical shape, and a conical protective cover is formed between the pulling rope 9 and the steel bundle, thereby separating the steel bundle and the hole wall. Prevent contact (that is, ensure that the tension rope is always in the center of the cross section in the pipeline and that there is an isolation layer between the pipe wall and the steel bundle), so that the steel bundle of the whole hole can be smoothly inserted into the hole. can be guaranteed. Next, by preparing a hole in the top plate 1 of the box beam, tensioning of the steel drawing wire and mortar pressing work are performed, so the operation space inside the box is narrow, and it is difficult to position and tension the oil cap. Solve a problem. Finally, by adding a groove to the front end of the tooth block as well as preparing a hole in the upper plate. To solve the problem of module strength of the anchor end of tooth block and difficult operation of concrete pouring. By applying construction methods such as "pull + prepare + stretch", pre-holes are installed in each part of the box beam, grooves are added, etc., and ultra-long prestressed steel bundles are inserted into the box beam, tension, mortar press,
To solve the problem that anchor embedding is difficult to operate due to space restrictions. In the construction process, the degree of difficulty in construction will be greatly reduced, and the construction cost will be reduced and the construction period will be shortened.

According to the above technical solution of the present invention, using the construction method of "pull + prepare + stretch", there are space restrictions and labor in constructing the upper surface ultra-long prestress steel bundle, and the hole wall by the steel drawn wire It solves the problems of easy destruction of the mortar, lack of mortar press, and difficulty of embedding anchors.

Moreover, it has the following technical effects.
1 Mechanical means may be employed in place of manual labor. The insertion machine provides power to realize the penetration of the steel drawing wire and improve the efficiency.
2 Make it "discrete → whole". By using a tension rope as a guide, it is possible to align the prestress bundle through the whole hole, and solve the problem that the cycle is long if repeated insertion work is performed using a single steel drawn wire. In addition, the full hole penetration can ensure the relative forward direction and relaxation between the steel drawn wires.
3 Prepare a reeving hole path in the beam plane. Both the steel draw wire and the threader are placed in the plane of the beam. The entire threading process basically takes place in the plane of the beam. Therefore, it is possible to effectively avoid adverse effects due to the limitation of the lower space.
4 The prestress connection end can be made into a conical end by steel wire slip knitting. It also has a protective cover on the front end, which effectively isolates the steel bundle and the hole wall.
To prevent stress concentration on an anchor receiving plate by adjusting the displacement of an anchor tool using a hole opening. The deep-buried anchor groove design simplifies the operation of embedding the anchor and guarantees the construction weight.
6. The application of this construction technology is highly efficient, rapid, and prestressed under the limited indoor space.
We have achieved the completion of high-quality prestressed construction, and this technology can be expanded horizontally.
It is applied to the construction of prestressed structures without construction conditions below, such as steel mixed beams, and has a wide range of applications.

The above are only preferred embodiments of the present invention, and should not be construed as limiting the present invention. should be included in the scope of protection.

Claims (10)

A method for constructing an ultra-long prestressed steel bundle, comprising:
positioning and assembling the prestress conduit 18;
inserting a top prestressed steel bundle;
tensioning the upper surface prestress;
mortar pressing the top prestress flux duct 18;
embedding a top surface prestress anchor;
A method for constructing an ultra-long prestressed steel bundle, characterized by: The steps of positioning and assembling the prestress conduit 18 include:
forming a longitudinal prestress hole with a corrugated tube of plastic material;
alternately operating pipe assembly, steel bar restraint, and module assembly;
a step of reliably soldering with a well-shaped positioning steel bar and a steel bar;
inspecting for ruptures in the ripple tube to prevent blockage of the conduit due to mortar leaks in the ripple tube;
preventing concrete solidification within the tube by pulling on the bushing;
The construction method for ultra-long prestressed steel bundles according to claim 1, characterized in that: The step of inserting the top surface prestressed steel bundle includes:
By preparing an oblique preliminary hole on the extension line corresponding to the position of the construction hole, the tension rope 9
a step of combining
drilling through the entire hole of the prestressed steel bundle 2;
The construction method for ultra-long prestressed steel bundles according to claim 1, characterized in that: The pulling rope 9 uses a single steel drawn wire and is mechanically penetrated by an inserter,
The construction method for ultra-long prestressed steel bundles according to claim 3, characterized in that: The step of inserting the top surface prestressed steel bundle includes:
a step of braiding a steel wire with a deviation of the steel drawn wire and processing the end of the steel bundle;
With the deep-buried anchor technology, the anchor receiving plate 11 is embedded in the groove inside the structure at a distance of 0.2 m from the outer circumference of the structure, and an extension cylinder is inserted between the anchor receiving plate 11 and the tensioning oil cap 17 during tensioning. placing and translating;
A reeving hole path is prepared at the front end of the tooth block, and the steel drawing wire of the entire bundle is drawn manually by assisting the machine. , cutting the steel drawn wire with the wheel;
The construction method for ultra-long prestressed steel bundles according to claim 3, characterized in that: The step of weaving the steel drawn wire with deviation and treating the end of the steel bundle,
forming a cone at the front end by offset knitting from a steel wire;
forming a conical shape by conically weaving one end of the tension rope with a fine steel wire and a steel draw wire through which the entire bundle should be inserted;
cutting the steel draw wire in the unwoven portion after threading with the wheel;
The construction method for ultra-long prestressed steel bundles according to claim 5, characterized in that: The top surface prestressing step includes:
Preparing two oil cap spare eyelets on the beam face, passing steel wire cables through it, and installing a chain hoist with a lifting means upside down on the beam face;
lifting the taut oil cap 17 in the beam by means of a chain hoist on top of the beam and mounting a control platform or an inspection truck in the beam;
attaching a stop plate, an anchor, a clip transition ring, and completing the tensioning;
The construction method for ultra-long prestressed steel bundles according to claim 1, characterized in that: The step of mortar pressing the upper surface prestress flux conduit 18 includes:
a step of performing mortar pressing within 48 hours after tension construction;
cutting the exposed steel wire and embedding the anchor;
arranging the mortar injection holes on the anchor receiving plate 11;
The construction method for ultra-long prestressed steel bundles according to claim 1, characterized in that: The mortar press method is
vacuum extraction, starting the vacuum pump to make the system negative pressure 0.07~0.1Mpa;
Stop the pump for 1 minute when the degree of vacuum in the tunnel becomes constant,
If the pressure drop is less than 0.02Mpa, it is determined that the hole is vacuum, and the pressure drop is 0.0
Determining that if greater than 2 MPa, the hole passage is not fully sealed and requires inspection and correction prior to mortar injection;
The construction method for ultra-long prestressed steel bundles according to claim 8, characterized in that: The step of embedding the top surface prestress anchor includes:
fixing the taut end anchor embedding module 22 directly from the top surface to the top surface of the beam by iron wire to reduce the problem of narrow operating space;
installing a preliminary hole 15 in the upper surface of the deep-buried anchor mouth;
pouring and shaking anchor-embedded concrete from the upper surface of the beam;
The construction method for ultra-long prestressed steel bundles according to claim 1, characterized in that:

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