Ultra-long prestress anti-floating anchor rod steel bar lengthening device and construction method

Abstract

The invention discloses a super-long prestress anti-floating anchor rod steel bar lengthening device and a construction method.The super-long prestress anti-floating anchor rod steel bar lengthening device comprises prestress steel bars, a connector, a corrugated pipe matched with the connector and a corrugated pipe matched with the steel bars, one ends of the two prestress steel bars are arranged in the connector in a sleeved mode, and the corrugated pipe matched with the connector is arranged on the connector in a sleeved mode; and the corrugated pipe matched with the reinforcing steel bar is sleeved on the prestressed reinforcing steel bar. The prestressed reinforcing steel bar connecting device has the beneficial effects that prestressed reinforcing steel bars are connected through the connectors, the corrugated pipes matched with the connectors and the corrugated pipes matched with the reinforcing steel bars, and the requirement for deformation generated during tensioning is met; the lubricating effect of the lubricating grease can better meet the deformation requirement of the prestressed reinforcement, and the corrugated pipe of the adaptive connector and the corrugated pipe of the adaptive reinforcement are prevented from being damaged when the prestressed reinforcement is deformed; through the buffering effect of the sponge strip, the connector is protected from being damaged during tension deformation; and the corrugated pipes at the joints are fixed by the heat shrink tubes and are connected into a whole, so that the effects of corrosion prevention and isolation can also be achieved.

Description

Technical Field

[0001] This invention relates to the field of building foundation treatment technology, and in particular to a device for extending ultra-long prestressed anti-buoyancy anchor bars and its construction method. Background Technology

[0002] Prestressed anti-buoyancy anchors, with their high load-bearing capacity, active deformation control capabilities, and economic advantages, have become a core anti-buoyancy method widely used in underground engineering in high-water-level areas. However, the standard length of conventional threaded steel bars in China is usually 12 meters, which is insufficient to meet the design requirements of ultra-long anchors, necessitating the use of mechanical connectors for extension. Since the connector diameter is larger than the steel bar itself, the corrugated pipe anti-corrosion system is interrupted at the joint, creating a weak point in corrosion protection. Existing wrapping methods such as heat-shrink tubing can create a "pseudo-anchoring section" at the connection point, interfering with the designed anchoring mechanism and hindering the free elongation of the steel bar during subsequent prestressing tensioning, thus reducing the effective length of the anchor. Using custom-made ultra-long steel materials presents the problems of increased costs and extended delivery cycles.

[0003] For example, a Chinese patent discloses an adjustable anchor for a PSB (Pre-stressed Bismuth Burner) threaded steel pre-stressed anti-buoyancy anchor rod (application number: CN202121531755.6). This invention addresses the problem of limited use of traditional anchor plates and heads and waste of PSB threaded steel when the end position of the PSB threaded steel pre-stressed anti-buoyancy anchor rod deviates. The present invention includes a PSB threaded steel pre-stressed anti-buoyancy anchor rod body, with the lower end of the rod extending into the anchor hole, and the upper end passing through a concrete pad layer above the anchor hole. An anchor body is formed between the PSB threaded steel pre-stressed anti-buoyancy anchor rod body and the anchor hole.

[0004] Therefore, there is an urgent need to develop a split-type variable diameter isolation technology that can adapt to tension deformation, maintain continuous corrosion protection throughout the entire section, and not interfere with the anchoring function. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide an ultra-long prestressed anti-buoyancy anchor bar splicing device and construction method to solve the above problems.

[0006] An ultra-long prestressed anti-buoyancy anchor bar extension device includes prestressed bars, connectors, a first corrugated pipe for adapting the connector, and a second corrugated pipe for adapting the bars. One end of each of the two prestressed bars is fitted inside the connector. The first corrugated pipe is fitted onto the connector, and the second corrugated pipe is fitted onto the prestressed bars.

[0007] Preferably, the space between the first bellows and the connector is filled with lubricating grease.

[0008] Preferably, the space between the prestressed steel bar and the second corrugated pipe is filled with lubricating grease.

[0009] Preferably, the connector has sponge strips at both ends.

[0010] Preferably, a heat shrink tubing is fitted onto the first corrugated pipe, and the heat shrink tubing extends and is fitted onto the second corrugated pipe.

[0011] Preferably, the prestressed steel bars are PSB1200 grade steel bars and are coated with epoxy anti-corrosion paint.

[0012] Preferably, the connector is a YGM connector, which has an internal thread that matches the prestressed steel bar.

[0013] Preferably, the ends of the two prestressed steel bars extend into the connector to the same length.

[0014] Preferably, both the first and second corrugated pipes are made of polyethylene.

[0015] A construction method for an ultra-long prestressed anti-buoyancy anchor bar splicing device, the method steps are as follows: S1. Connecting Reinforcing Bars: Connect two prestressed reinforcing bars using connectors to ensure that the connection lengths of the two prestressed reinforcing bars and the connectors are consistent and tightly fitted. S2. Install the corrugated tube: Apply lubricating grease to the surface of the connector and the inside of the first corrugated tube of the adapter connector. Slide the first corrugated tube of the adapter connector onto the connector. The first corrugated tube should be longer than the connector. Similarly, slide the second corrugated tube of the adapter steel bar onto the prestressed steel bar and fill it with lubricating grease. Connect the second corrugated tube to the connector. S3. Insert the sponge strip: Insert the sponge strip into both ends of the connector inside the first corrugated tube, that is, sandwiched between the first and second corrugated tubes; S4. Fixing: Place the heat shrink tubing longer than the first corrugated tube onto the connection point, heat it to shrink it, and firmly wrap and fix the connection device, so that the corrugated tubes at the connection point become one piece.

[0016] Preferably, the outer circumference of the connector is provided with a plurality of reinforcing ribs, the reinforcing ribs being triangular in shape.

[0017] Preferably, both ends of the connector are provided with a number of grooves and protrusions that mate with the grooves, so that connectors of different lengths can be assembled according to usage requirements.

[0018] Preferably, the heat shrink tubing is made of cross-linked polyolefin material.

[0019] Compared with existing technologies, the present invention has the following advantages: The present invention connects prestressed steel bars and meets the deformation requirements during tensioning by using a connector and a corrugated tube for the connector and a corrugated tube for the reinforcing bar; the lubricating effect of the lubricating grease better meets the deformation needs of the prestressed steel bars and avoids damage to the corrugated tubes of the connector and the reinforcing bar during deformation; the sponge strips are installed at both ends of the connector and wrapped inside the corrugated tubes, protecting the connector from damage during tension deformation through the buffering effect of the sponge strips; the heat shrink tubing fixes the corrugated tubes at the connection point and connects the corrugated tubes of the connector and the reinforcing bar into a whole, also serving as a corrosion-resistant barrier. Attached Figure Description

[0020] Figure 1 This is a structural diagram of the present invention; Figure 2 This is a structural diagram of the unfolded state of the present invention; Figure 3 and Figure 4 This is a structural diagram of the connector of the present invention; Figure 5 This is a structural diagram of the two connectors assembled according to the present invention; Figure 6 This is a schematic diagram of the cross-section of the reinforcing rib of the present invention.

[0021] The attached diagram is labeled as follows: 1. Prestressed steel bar; 2. Connector; 21. Reinforcing rib; 22. Groove; 23. Protrusion; 3. First corrugated pipe; 4. Second corrugated pipe; 5. Lubricating grease; 6. Sponge strip; 7. Heat shrink tubing. Detailed Implementation

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0023] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention 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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0026] like Figure 1 and combined Figures 2 to 6 As shown, an ultra-long prestressed anti-buoyancy anchor bar extension device includes a prestressed bar 1, a connector 2, a first corrugated pipe 3 adapted to the connector, and a second corrugated pipe 4 adapted to the bar. One end of each of the two prestressed bars 1 is respectively fitted inside the connector 2. The first corrugated pipe 3 is fitted on the connector 2, and the second corrugated pipe 4 is fitted on the prestressed bar 1.

[0027] Furthermore, lubricating grease 5 is filled between the first bellows 3 and the connector 2.

[0028] The benefits of adopting a further technical solution are that the lubricating grease 5 can better meet the deformation needs of the prestressed steel bar 1, and avoid damage to the first corrugated pipe 3 when the prestressed steel bar 1 deforms.

[0029] Furthermore, the space between the prestressed steel bar 1 and the second corrugated pipe 4 is filled with lubricating grease 5.

[0030] The benefits of adopting a further technical solution are that the lubricating grease 5 can better meet the deformation needs of the prestressed steel bar 1, and avoid damage to the second corrugated pipe 4 when the prestressed steel bar 1 deforms.

[0031] Furthermore, sponge strips 6 are provided at both ends of the connector 2.

[0032] The benefits of adopting a further technical solution are: the buffering effect of the sponge strip 6 protects the connector 2 from damage during tension deformation.

[0033] Furthermore, a heat shrink tube 7 is fitted onto the first corrugated pipe 3, and the heat shrink tube 7 extends and is fitted onto the second corrugated pipe 4.

[0034] The benefits of adopting a further technical solution: the heat shrink tubing 7 is fitted onto the first corrugated tube 3 and the second corrugated tube 4. After being heated and shrunk, it can further enhance the sealing and integrity of the connection, effectively prevent moisture intrusion, and improve the durability of the device.

[0035] Furthermore, the prestressed steel bar 1 is a PSB1200 grade steel bar and its surface is coated with epoxy anti-corrosion paint.

[0036] The following benefits are derived from the adoption of further technical solutions: Prestressed steel bar 1 uses PSB1200 grade steel bars, which have high strength and tensile properties, meeting the stress requirements of ultra-long prestressed anti-buoyancy anchor rods. Applying epoxy anti-corrosion coating to the surface enhances the corrosion resistance of the steel bars and extends their service life.

[0037] Furthermore, the connector 2 is a YGM connector, and the connector 2 has an internal thread that matches the prestressed steel bar 1.

[0038] The benefits of adopting a further technical solution are as follows: Connector 2 is a YGM connector, which has an internal thread that matches the prestressed steel bar 1, which can ensure a reliable threaded connection between the prestressed steel bar and the connector, and guarantee the connection strength and force transmission effect.

[0039] Furthermore, the ends of the two prestressed steel bars 1 extend into the connector 2 at the same length.

[0040] The benefits of adopting a further technical solution are as follows: the ends of the two prestressed steel bars 1 extend into the connector 2 at the same length, which can make the connector evenly stressed, avoid weak points in the connection due to uneven stress, and ensure the stability and reliability of the connection.

[0041] Furthermore, both the first corrugated pipe 3 and the second corrugated pipe 4 are made of polyethylene.

[0042] The benefits of adopting further technical solutions are as follows: the first corrugated pipe 3 and the second corrugated pipe 4 are made of polyethylene material, which has good corrosion resistance, flexibility and anti-aging properties, can effectively protect the internal connectors and prestressed steel bars, and is easy to install and bend.

[0043] A construction method for an ultra-long prestressed anti-buoyancy anchor bar splicing device, the method steps are as follows: S1. Connecting steel bars: Connector 2 is used to connect two prestressed steel bars 1, ensuring that the connection length of the two prestressed steel bars 1 and connector 2 is consistent and fits tightly. S2. Install the corrugated pipe: Apply lubricating grease 5 to the surface of connector 2 and the inside of the first corrugated pipe 3, and put the first corrugated pipe 3 on connector 2. The first corrugated pipe 3 should be longer than connector 2. Similarly, put the prestressed steel bar 1 on the second corrugated pipe 4 and fill it with lubricating grease 5. The second corrugated pipe 4 is connected to connector 2. S3. Insert the sponge strip: Insert the sponge strip 6 into both ends of the connector 2 inside the first corrugated pipe 3, that is, sandwiched between the first corrugated pipe 3 and the second corrugated pipe 4. S4. Fixing: Place the heat shrink tubing 7, which is longer than the first corrugated tube 3, on the connection point, heat it to shrink it, and firmly wrap and fix the connection device so that the corrugated tubes at the connection point become a whole.

[0044] Furthermore, the outer circumference of the connector 2 is provided with a plurality of reinforcing ribs 21, the reinforcing ribs 21 being triangular in shape.

[0045] The benefits of adopting further technical solutions: The triangular reinforcing ribs 21 provided on the outer circumference of connector 2 can enhance the structural strength and rigidity of the connector, improve its ability to resist external deformation during use, and ensure the stability of the connection part.

[0046] Furthermore, both ends of the connector 2 are provided with several grooves 22 and protrusions 23 that cooperate with the grooves 22, so that connectors of different lengths can be assembled according to usage requirements.

[0047] The adoption of further technical solutions has the following benefits: The design of the grooves 22 and protrusions 23 at both ends of the connector 2 allows for the assembly of connectors of different lengths according to usage requirements, increasing the flexibility and adaptability of the device and enabling it to meet the requirements for rebar extension of ultra-long prestressed anti-buoyancy anchor rods in different engineering scenarios.

[0048] Furthermore, the heat shrink tubing 7 is made of cross-linked polyolefin material.

[0049] The benefits of adopting further technical solutions: The heat shrink tubing 7 is made of cross-linked polyolefin material, which has high heat resistance, flexibility and shrinkage performance. After heating, it can tightly wrap around the corrugated tube to form a good sealing and protection effect, while having a long service life.

[0050] Compared with the prior art, the present invention has the following advantages: The present invention connects the prestressed steel bars 1 through the connector 2 and the first corrugated pipe 3 and the second corrugated pipe 4, and meets the deformation requirements generated during tensioning; the lubricating effect of the lubricating grease 5 can better meet the deformation needs of the prestressed steel bars 1, and avoid damage to the first corrugated pipe 3 and the second corrugated pipe 4 when the prestressed steel bars 1 deform; the sponge strip 6 is installed at both ends of the connector 2 and is wrapped inside the corrugated pipe. Through the buffering effect of the sponge strip 6, the connector 2 is protected from damage during tensioning deformation; the heat shrink tubing 7 fixes the corrugated pipe at the connection and connects the corrugated pipe 3 that adapts to the connector and the corrugated pipe 4 that adapts to the steel bars into a whole, which can also play a role in corrosion prevention and isolation.

[0051] Working principle: Step 1: Connecting the reinforcing bars: Use connector 2 to connect the two prestressed reinforcing bars 1, ensuring that the connection lengths of the two prestressed reinforcing bars 1 and connector 2 are consistent and tightly fitted. Step 2: Install the corrugated tube: Apply lubricating grease 5 to the surface of connector 2 and the inside of the first corrugated tube 3 used for the adapter connector. Put the first corrugated tube 3 used for the adapter connector onto connector 2. The first corrugated tube 3 used for the adapter connector should be longer than connector 2. Similarly, put the second corrugated tube 4 of the adapter steel bar 1 onto the prestressed steel bar and fill it with lubricating grease 5. The second corrugated tube 4 of the adapter steel bar is connected to connector 2. Step 3: Insert the sponge strip: Insert the sponge strip 6 into both ends of the connector 2 inside the first corrugated tube 3 of the adapter connector, that is, sandwiched between the first corrugated tube 3 of the adapter connector and the second corrugated tube 4 of the adapter steel bar. Step 4: Place the heat shrink tubing 7, which is longer than the first corrugated tube 3 of the adapter connector, onto the connection point, heat it to shrink it, and firmly wrap and fix the connection device so that the corrugated tube at the connection point becomes a whole.

[0052] Example 1: Application of Anti-buoyancy Engineering in Deep Foundation Pit This embodiment is applied to the construction of anti-buoyancy anchor bolts in a 30m deep underground foundation pit, which requires two 18m long prestressed steel bars to be extended into a 36m integral structure.

[0053] The prestressed steel bars are PSB1200 grade steel bars with a diameter of 25mm, and the surface is coated with epoxy paint for corrosion protection. The tensile strength of a single steel bar is ≥1200MPa.

[0054] The connector is a YGM25 type threaded connector, with internal threads that match the steel bars, and four triangular reinforcing ribs evenly distributed on the outer circumference, with a rib height of 8mm.

[0055] The first corrugated pipe is a polyethylene pipe with a diameter of 50mm and a length of 400mm; the second corrugated pipe is a polyethylene pipe with a diameter of 32mm and a length of 2000mm.

[0056] The heat shrink tubing is made of cross-linked polyolefin material, with a length of 500mm and a shrinkage rate of ≥50%.

[0057] In step S1, the length of each of the two steel bars extending into the connector is 100mm, and they are tightened to 350N・m using a torque wrench.

[0058] In step S2, lithium-based grease is used as the lubricant, and the filling amount is 60% of the volume of the first bellows to ensure that the connector surface is completely covered.

[0059] In step S3, the sponge strip is a closed-cell sponge with a diameter of 45mm and a length of 50mm, which is inserted into the gap between the two ends of the connector and the second corrugated tube.

[0060] In step S4, the heating temperature of the heat shrink tubing is controlled at 120-150℃, and it is heated evenly from the middle to both ends to form a sealing ring.

[0061] The device exhibited good integrity during the tension test. When tensioned to 1.2 times the design load, the deformation at the connection point was ≤2mm, and there was no water leakage at the heat shrink tubing seal, meeting the requirements for use in deep foundation pits with long-term water immersion.

[0062] Example 2: Application of Ultra-Deep Underground Utility Tunnel Engineering This embodiment is applied to an ultra-deep underground utility tunnel 50m underground. The extended anchor rods need to withstand a tensile force of 1500kN. The ultra-long connection is achieved by assembling two connector sections.

[0063] The prestressed steel bars are PSB1200 grade steel bars with a diameter of 32mm and an epoxy paint dry film thickness of ≥120μm.

[0064] The connector is assembled from two YGM32 connectors, each 150mm long. They are connected by three sets of grooves and protrusions at the ends, with a total length of 280mm after assembly. There are six triangular reinforcing ribs on the outer circumference.

[0065] The first corrugated pipe has a diameter of 63mm and a length of 500mm; the second corrugated pipe has a diameter of 40mm and a length of 3000mm, both made of high-density polyethylene.

[0066] The heat shrink tubing is 800mm long, has a wall thickness of ≥2mm, and a temperature range of -40℃ to 125℃.

[0067] In step S1, the length of the reinforcing bar inserted into the connector after assembly is 120mm, and the engagement depth of the groove and protrusion at the splice is ≥5mm.

[0068] In step S2, polyurea grease is used for filling, and the gap between the first corrugated pipe and the connector is filled with 70%. The filling length inside the second corrugated pipe is 1.5 times the length of the reinforcing bar extension.

[0069] In step S4, the heat shrink tubing is heated to form three sealing rings, each ring being ≥50mm wide, and an airtightness test is used to ensure there is no leakage.

[0070] In the 50m water head pressure test, there was no leakage at the connection. After 1 million fatigue tests, the connection strength retention rate was ≥95%, which meets the durability requirements of ultra-deep underground structures.

[0071] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A device for extending the reinforcing bars of an ultra-long prestressed anti-buoyancy anchor rod, characterized in that: It includes prestressed steel bars (1), connectors (2), a first corrugated pipe (3) for adapting the connector and a second corrugated pipe (4) for adapting the steel bars. One end of each of the two prestressed steel bars (1) is fitted inside the connector (2), the first corrugated pipe (3) is fitted on the connector (2), and the second corrugated pipe (4) is fitted on the prestressed steel bars (1). Lubricating grease (5) is filled between the first bellows (3) and the connector (2); The space between the prestressed steel bar (1) and the second corrugated pipe (4) is filled with lubricating grease (5). The connector (2) has sponge strips (6) at both ends.

2. The ultra-long prestressed anti-buoyancy anchor rod reinforcement splicing device as described in claim 1, characterized in that: A heat shrink tube (7) is fitted on the first corrugated tube (3), and the heat shrink tube (7) extends and is fitted on the second corrugated tube (4).

3. The ultra-long prestressed anti-buoyancy anchor rod rebar splicing device as described in claim 1, characterized in that: The prestressed steel bar (1) is a PSB1200 grade steel bar and its surface is coated with epoxy anti-corrosion paint.

4. The ultra-long prestressed anti-buoyancy anchor rod rebar splicing device as described in claim 1, characterized in that: The connector (2) is a YGM connector, and the connector (2) has an internal thread that matches the prestressed steel bar (1).

5. The ultra-long prestressed anti-buoyancy anchor rod rebar splicing device as described in claim 1, characterized in that: The ends of the two prestressed steel bars (1) extend into the connector (2) to the same length.

6. The ultra-long prestressed anti-buoyancy anchor rod reinforcement splicing device as described in claim 1, characterized in that: The first corrugated pipe (3) and the second corrugated pipe (4) are both made of polyethylene.

7. A construction method for an ultra-long prestressed anti-buoyancy anchor bar splicing device as described in any one of claims 1-6, characterized in that: The method and steps are as follows: S1. Connecting steel bars: Connect the two prestressed steel bars (1) with connector (2) to ensure that the connection length of the two prestressed steel bars (1) and connector (2) is consistent and fits tightly. S2. Install the corrugated pipe: Apply lubricating grease (5) to the surface of the connector (2) and the inside of the first corrugated pipe (3) of the adapter connector. Put the first corrugated pipe (3) of the adapter connector on the connector (2). The first corrugated pipe (3) of the adapter connector should be longer than the connector (2). Similarly, put the second corrugated pipe (4) of the prestressed steel bar (1) on the adapter steel bar and fill it with lubricating grease (5). The second corrugated pipe (4) of the adapter steel bar is connected to the connector (2). S3, Insert the sponge strip: Insert the sponge strip (6) into both ends of the connector (2) inside the first corrugated tube (3) of the adapter connector, that is, sandwiched between the first corrugated tube (3) of the adapter connector and the second corrugated tube (4) of the adapter steel bar; S4. Fixing: The heat shrink tube (7) of the first corrugated tube (3) longer than the adapter connector is placed on the connection, heated to shrink it, and firmly wraps and fixes the connection device, so that the corrugated tube at the connection is integrated.

8. The method for splicing ultra-long prestressed anti-buoyancy anchor bars as described in claim 7, characterized in that: The connector (2) has a number of reinforcing ribs (21) on its outer circumference, and the reinforcing ribs (21) are triangular in shape.

9. The method for splicing ultra-long prestressed anti-buoyancy anchor bars as described in claim 7, characterized in that: Both ends of the connector (2) are provided with several grooves (22) and protrusions (23) that cooperate with the grooves (22) to connect with each other, so that connectors of different lengths can be assembled according to the usage requirements.

10. The method for splicing ultra-long prestressed anti-buoyancy anchor bars as described in claim 7, characterized in that: The heat shrink tubing (7) is made of cross-linked polyolefin material.

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