Anti-floating structure of pre-stressed anchor rod

Abstract

The utility model discloses a pre-stressed anchor rod anti-floating structure which comprises a pre-stressed anchor rod and a bottom plate, and the pre-stressed anchor rod comprises an anchor rod body and a rib body. The device further comprises an anchor rod connecting device, the anchor rod connecting device comprises a first plate component, a second plate component and a connecting piece, and the second plate component is located above the first plate component. The first plate component is located in the anchor rod body, the second plate component is located in the bottom plate, one part of the connecting piece is located in the anchor rod body, and one part of the connecting piece is located in the bottom plate; an anchorage device is arranged above the second plate component, the rib body penetrates through the first plate component and the second plate component, and the top end of the rib body is fixedly connected with the anchorage device; the top ends of the anchorage devices and the top ends of the rib bodies are located in the bottom plate. The top of the anchor rod can be effectively protected from being damaged by local compression, the elevation control requirement for the top of the anchor rod body is lowered, and the construction efficiency and quality can be improved.

Description

Technical Field

[0001] This utility model relates to a prestressed anchor anti-buoyancy structure, belonging to the technical field of anti-buoyancy structures for underground building structures. Background Technology

[0002] Most basements have buoyancy issues. According to the "Technical Standard for Anti-buoyancy of Building Engineering" JGJ476-2019, projects with an anti-buoyancy design level of A or B should be designed to prevent cracking and should use prestressed anti-buoyancy anchors. Prestressed anti-buoyancy anchors can use steel strands or precision-rolled threaded steel as prestressing tendons.

[0003] Existing patent 1 (publication number CN214993801U) discloses a prestressed anti-buoyancy anchor technology that completes tensioning and locking before the basement floor slab is poured. It achieves the connection and anchoring of the anchor to the floor slab (basement floor slab) by setting a prestress transfer device at the top of the anchor. During tensioning, the top of the anchor has poor stability and is subjected to a large concentrated force. When the applied prestress is too high or the strength of the top of the anchor is insufficient, it is easy to cause local crushing and failure of the top of the anchor. To solve this problem, it is often necessary to set a reinforcing structure such as spiral steel bars at the top of the anchor to improve its compressive bearing capacity. Existing patent 2 (publication number CN115538430A) discloses a prestressed anti-buoyancy anchor scheme with spiral steel bars set at the top of the anchor body, thereby improving the compressive strength of the top of the anchor body.

[0004] Furthermore, in the existing patent 1, the design of the anti-buoyancy structure requires precise control of the elevation of the top of the anchor rod. This ensures that after the prestressing transfer device and anchor are installed at the top of the anchor rod, the entire prestressing transfer device, anchor, and reinforcement must be positioned within the basement floor slab at the designated elevation, preventing the anchor and reinforcement from being exposed on the upper surface of the basement floor slab. Simultaneously, if the elevation of the prestressing transfer device is lower than the designated elevation, it will affect the anchorage connection bearing capacity between the anchor rod and the basement floor slab. The precise control of the top elevation of the anchor rod during anchor construction is detrimental to improving construction efficiency and increases the workload for construction workers. Utility Model Content

[0005] To overcome the problems existing in prestressed anchor anti-buoyancy structures in the prior art, this utility model provides a prestressed anchor anti-buoyancy structure and its construction method. This not only reduces the requirements for the top elevation of the anchor rod but also improves the overall connection between the anchor rod and the base plate, which helps prevent or reduce the possibility of tension damage to the top of the anchor rod. The specific technical solution is as follows.

[0006] A prestressed anchor anti-buoyancy structure includes a prestressed anchor and a base plate. The prestressed anchor includes an anchor body and a reinforcing bar, the lower end of which is located inside the anchor body. The structure is characterized by:

[0007] It also includes an anchor bolt connection device, which comprises a first plate component, a second plate component, and a connector connecting the first plate component and the second plate component. The second plate component is located above the first plate component. The first plate component is located inside the anchor bolt body, and the second plate component is located inside the base plate. A portion of the connector is located inside the anchor bolt body, and a portion of the connector is located inside the base plate. An anchor is provided above the second plate component. The reinforcing bar passes through the first plate component and the second plate component, and the top end of the reinforcing bar is fixedly connected to the anchor. Both the anchor and the top end of the reinforcing bar are located inside the base plate.

[0008] In the above scheme, the top of the prestressed anchor rod is fixed to the second plate component of the anchor rod connection device via an anchor. The construction of the prestressed anchor rod and the prestressing tensioning are independent of the base slab. The basement base slab can be constructed as a whole after the prestressing tensioning is completed, avoiding the overlap between the construction of the prestressed anchor rod and the construction of the basement base slab. Using this technical solution, it is not necessary to precisely control the elevation of the top of the anchor rod; only the elevation of the second plate component of the anchor rod connection device needs to be adjusted, greatly simplifying the construction process and reducing the workload of construction personnel. Simultaneously, the first plate component and part of the connector of the anchor rod connection device are located inside the top of the anchor rod, which can diffuse the pressure of the anchor on the top of the anchor rod during prestressing tensioning. This provides a stronger and more stable effect than the spiral reinforcement in existing technologies, preventing damage to the anchor rod during prestressing tensioning.

[0009] Furthermore, the first plate component and the second plate component are circular, square, or polygonal. Both the first plate component and the second plate component are provided with through holes for the ribs to pass through.

[0010] Furthermore, the connector is a cylindrical structure, with its extension direction parallel to that of the anchor rod body. The reinforcing rib passes through the cylindrical structure, and the outer diameter of the second plate component is larger than the diameter of the cylindrical structure. The cross-section of the cylindrical structure is circular, rectangular, or polygonal. The cylindrical structure can better withstand prestress, ensuring uniform stress distribution on the first or second plate component; the second plate component can be better anchored in the base plate, transferring the buoyancy of the base plate to the prestressed anchor rod. Preferably, a through hole is provided on the side wall of the cylindrical structure. Through this through hole, grouting material for the anchor rod body can be injected into the cylindrical structure, and the concrete of the basement base plate can also be filled into the interior of the cylindrical structure through this through hole, improving the integrity of the anchor rod connection device and the base plate.

[0011] Furthermore, studs are fixedly installed on the outer wall of the cylindrical structure. The studs help to increase the interlocking and bonding effect between the cylindrical structure and the anchor bolt body (anchor bolt grout).

[0012] Furthermore, the connector comprises several columns, the cross-section of which is circular, square, T-shaped, elliptical, trapezoidal, or polygonal. To ensure balanced force distribution, three or more columns are typically evenly distributed.

[0013] Furthermore, the connector also includes a crossbar connecting the two columns. The connector formed by the columns and the crossbar constitutes a hollow support, which has good stability and ensures that the grout of the anchor body and the concrete of the base plate can fully fill the space between the columns. Preferably, reinforcing ribs are provided at both the top and bottom of the columns.

[0014] Furthermore, the reinforcing bars are made of steel strand or threaded steel. Steel strand is low-cost, simple to tension, and easy to operate as a prestressing reinforcing bar; threaded steel has high strength and good tensile properties, which helps to save materials and reduce costs.

[0015] This utility model features simple construction, reliable quality, and good economy. Compared with the prior art, it has the following advantages:

[0016] 1. By embedding an anchor bolt connection device at the top of the anchor bolt body, the anchor bolt body and the base plate can be better connected as a whole;

[0017] 2. The anchor bolt connection device is embedded in the top of the anchor bolt body for a certain length, which disperses the concentrated force at the top of the anchor bolt in the traditional method during the tensioning process, and can effectively protect the top of the anchor bolt from local pressure damage;

[0018] 3. The anchor bolt connection device is embedded in the top of the anchor bolt body, which can save the spiral reinforcement that is set in the top of the anchor bolt in the traditional way, and the anchor bolt connection device embedded in the top of the anchor bolt body has a better reinforcement effect on the top of the anchor bolt.

[0019] 4. It reduces the elevation control requirements for the top of the anchor bolt, making the height control of the anchor bolt more flexible, which helps to improve construction efficiency and reduce the workload of construction personnel. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the prestressed anchor bolt anti-buoyancy structure of Embodiment 1 of this utility model;

[0021] Figure 2 This is a schematic diagram of the anchor bolt connection device according to Embodiment 1 of this utility model;

[0022] Figure 3 yes Figure 2 Schematic diagram of section 1-1 in the diagram;

[0023] Figure 4 This is a schematic diagram of a modified example of the anchor bolt connection device of Embodiment 1 of this utility model;

[0024] Figure 5 This is a schematic diagram of the elevation adjustment auxiliary device used during the construction of the prestressed anchor anti-buoyancy structure of Embodiment 1 of this utility model;

[0025] Figure 6 This is a schematic diagram of the anchor bolt connection device according to Embodiment 2 of this utility model;

[0026] Figure 7 yes Figure 6 Schematic diagram of section 2-2 in the figure;

[0027] Figure 8 This is a schematic diagram of a modified example of the anchor bolt connection device of Embodiment 2 of this utility model.

[0028] In the diagram: 1. Base plate; 2. Anchor bolt body; 3. Reinforcing bar; 4. Anchor bolt connection device; 4.1 First plate component; 4.2 Second plate component; 4.3 Cylindrical structure; 4.3.1 Stud; 4.4 Column; 4.5 Horizontal bar; 4.6 Through hole; 4.7 Through hole; 4.8 Reinforcing rib; 5. Anchor hole; 6. Elevation adjustment auxiliary device; 6.1 Support component; 6.2 Adjusting sleeve; 6.3 Screw; 7. Anchor; 8. Waterproof layer; 9. Foundation; 10. Subbase. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings.

[0030] Example 1

[0031] See Figures 1-3 A prestressed anchor anti-buoyancy structure includes a prestressed anchor and a base plate 1. The prestressed anchor includes an anchor body 2 and a reinforcing bar 3, with the lower end of the reinforcing bar 3 located inside the anchor body 2. It also includes an anchor connection device 4, which includes a first plate component 4.1, a second plate component 4.2, and a connector connecting the first plate component 4.1 and the second plate component 4.2. The second plate component 4.2 is located above the first plate component 4.1. The first plate component 4.1 is located inside the anchor body 2, the second plate component 4.2 is located inside the base plate 1, a portion of the connector is located inside the anchor body 2, and a portion of the connector is located inside the base plate 1. An anchor 7 is provided above the second plate component 4.2. The reinforcing bar 3 penetrates the first plate component 4.1 and the second plate component 4.2, and the top end of the reinforcing bar 3 is fixedly connected to the anchor 7. Both the anchor 7 and the top end of the reinforcing bar 3 are located inside the base plate 1. Typically, a cushion layer 10 is laid on top of the foundation 9, a waterproof layer 8 is laid on top of the cushion layer 10, and a reinforced concrete base slab 1 is formed on top of the waterproof layer 8.

[0032] The first plate component 4.1 and the second plate component 4.2 can be circular, square, or polygonal in shape. Both the first plate component 4.1 and the second plate component 4.2 are provided with through holes 4.6 for the rib 3 to pass through.

[0033] The connector is a cylindrical structure 4.3, whose extension direction is parallel to that of the anchor rod body 2. The reinforcing rib 3 passes through the cylindrical structure 4.3, and the outer diameter of the second plate component 4.2 is larger than the diameter of the cylindrical structure 4.3. The cross-section of the cylindrical structure 4.3 is circular, rectangular, or polygonal. The cylindrical structure 4.3 can effectively withstand prestress, ensuring uniform stress distribution on the first plate component 4.1 or the second plate component 4.2. The second plate component 4.2 can be well anchored in the base plate 1, transferring the buoyancy of the base plate 1 to the prestressed anchor rod. Preferably, a through hole 4.7 is provided on the side wall of the cylindrical structure 4.3. Through this through hole 4.7, some grouting material of the anchor rod body 2 can be injected into the cylindrical structure 4.3, and the concrete of the basement base plate 1 can also be filled into the interior of the cylindrical structure 4.3 through this through hole 4.7, improving the integrity of the anchor rod connection device 4 and the base plate 1.

[0034] like Figure 4 As shown, preferably, a stud 4.3.1 is fixedly provided on the outer wall of the cylindrical structure 4.3. The stud 4.3.1 helps to increase the interlocking and bonding effect between the cylindrical structure 4.3 and the anchor body 2 (anchor grout).

[0035] Furthermore, reinforcement 3 is made of steel strand or rebar. Steel strand is low-cost, simple to tension, easy to operate, and has low cost as a prestressing reinforcement; rebar has high strength and good tensile properties, which helps to save materials and reduce costs.

[0036] See Figures 1-5 The construction method of the above-mentioned prestressed anchor anti-buoyancy structure mainly includes the following steps:

[0037] 1) Drill anchor holes 5 at the designated locations on the foundation 9 and place the reinforcing bars 3 into the anchor holes 5;

[0038] 2) Place the anchor bolt connection device 4, allowing the reinforcing bar 3 to pass through the first plate component 4.1 and the second plate component 4.2 of the anchor bolt connection device 4;

[0039] 3) Use the elevation adjustment auxiliary device 6 to fix the elevation of the anchor bolt connection device 4;

[0040] 4) Grout is injected into the anchor hole 5 to form the anchor rod body 2, and a certain amount of grout for the anchor rod body 2 is also injected into the cylindrical structure 4.3 through the through hole 4.7;

[0041] 5) After the anchor body 2 reaches the design strength, place the anchor 7 above the second plate component 4.2 and prestress the reinforcement 3. After tensioning, use the anchor 7 to lock the reinforcement 3.

[0042] 6) Construct the base plate 1, and house the second plate component 4.2, the anchor 7 and the top of the reinforcement 3 inside the base plate 1. The concrete of the base plate 1 will also be filled into the interior of the cylindrical structure 4.3 through the through hole 4.7.

[0043] like Figure 5 As shown, the elevation adjustment auxiliary device 6 includes a support member 6.1 and a height adjustment mechanism. The height adjustment mechanism includes an adjusting sleeve 6.2 and two screws 6.3. The two screws 6.3 are threaded to both ends of the adjusting sleeve 6.2, and the external threads of the two screws 6.3 rotate in opposite directions. When the construction worker rotates the adjusting sleeve 6.2, the overall length of the two screws 6.3 can be adjusted, thereby adjusting the height of the support member 6.1, which abuts against the lower surface of the second plate component 4.2. Those skilled in the art will understand that other structural forms of the elevation adjustment auxiliary device 6 can also be used, as long as the anchor bolt connection device 4 (second plate component 4.2) can be positioned at the set height.

[0044] The construction of anchor bolt body 2 and the tensioning process of reinforcement body 3 are both existing technologies.

[0045] In this embodiment, the top of the prestressed anchor rod rib 3 is fixed to the second plate component 4.2 of the anchor rod connection device 4 via the anchor 7. The construction of the prestressed anchor rod and the prestressing tensioning are independent of the base slab 1. The basement base slab 1 can be constructed as a whole after the prestressing tensioning is completed, avoiding the overlap between the construction of the prestressed anchor rod and the construction of the basement base slab 1. Using this embodiment, it is not necessary to precisely control the elevation of the top of the anchor rod body 2. Only the elevation of the second plate component 4.2 of the anchor rod connection device 4 needs to be adjusted, which greatly simplifies the construction process and reduces the workload of construction personnel. At the same time, the first plate component 4.1 and part of the connector of the anchor rod connection device 4 are located inside the top of the anchor rod body 2, which can play the role of the spiral steel bar in the prior art, that is, to improve the compressive bearing capacity of the top of the anchor rod body 2 and prevent damage to the anchor rod body 2 when the rib 3 is prestressed.

[0046] The anti-buoyancy principle of the anti-buoyancy structure in this embodiment is as follows: When the base plate 1 is subjected to upward buoyancy from groundwater, the base plate 1 transmits the upward buoyancy to the second plate component 4.2 and the cylindrical structure 4.3 of the anchor bolt connection device 4. The upward force on the second plate component 4.2 is directly transmitted to the anchor 7 and the reinforcing bar 3. The reinforcing bar 3 transmits the upward force to the anchor bolt 2. The anchor bolt 2 is anchored to the foundation 9, thereby resisting (counteracting) the upward force. In other words, the buoyancy of the basement base plate 1 is ultimately transmitted to the anchor bolt 2 and the foundation 9. Since the reinforcing bar 3 is in a tensile state after being prestressed, the tendency of the reinforcing bar 3 to recoil makes the anchor bolt always in a compressive state. Thus, the anchor bolt is less prone to cracks and fissures, thereby meeting the requirements of relevant standards.

[0047] The second plate component 4.2 of the anchor bolt connection device 4 serves as a support surface for the anchor 7 on the one hand, and on the other hand, it fixes the basement floor slab 1 together and transmits anti-buoyancy force.

[0048] Example 2

[0049] See Figures 6-7 The difference between Embodiment 2 and Embodiment 1 is that the connector is not a cylindrical structure, but rather includes several uprights 4.4. The cross-section of the uprights 4.4 is circular, square, T-shaped, elliptical, trapezoidal, or polygonal, etc. To ensure balanced force distribution, three or more uprights 4.4 are typically evenly distributed. Figure 8 As shown, preferably, the connector also includes a crossbar 4.5 connecting the two columns 4.4. The connector formed by the columns 4.4 and the crossbar 4.5 together constitutes a hollow support, which has good stability and ensures that the grout of the anchor body 2 and the concrete of the base plate 1 can be fully filled in the space between the columns 4.4. Preferably, the top and bottom ends of the columns 4.4 are provided with reinforcing ribs 4.8.

[0050] The embodiments of the present invention have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention is not limited to the specific embodiments described above; these embodiments are merely illustrative and not limiting. Those skilled in the art, under the guidance of the present invention, can make many modifications without departing from the spirit and scope of the claims, and all such modifications fall within the protection scope of the present invention.

Claims

1. A prestressed anchor anti-buoyancy structure, comprising a prestressed anchor and a base plate (1), wherein the prestressed anchor comprises an anchor body (2) and a reinforcing bar (3), the lower end of the reinforcing bar (3) being located inside the anchor body (2), characterized in that: It also includes an anchor bolt connection device (4), which includes a first plate component (4.1), a second plate component (4.2), and a connector connecting the first plate component (4.1) and the second plate component (4.2). The second plate component (4.2) is located above the first plate component (4.1). The first plate component (4.1) is located inside the anchor bolt body (2), and the second plate component (4.2) is located inside the base plate (1). A portion of the connector is located inside the anchor bolt body (2), and a portion of the connector is located inside the base plate (1). An anchor (7) is provided above the second plate component (4.2). The rib (3) passes through the first plate component (4.1) and the second plate component (4.2). The top end of the rib (3) is fixedly connected to the anchor (7). The top ends of the anchor (7) and the rib (3) are both located inside the base plate (1).

2. The prestressed anchor bolt anti-buoyancy structure according to claim 1, characterized in that, The first plate component (4.1) and the second plate component (4.2) are circular, square or polygonal.

3. A prestressed anchor bolt anti-buoyancy structure according to claim 1 or 2, characterized in that, The connector is a cylindrical structure (4.3), the extension direction of the cylindrical structure (4.3) is parallel to the extension direction of the anchor rod body (2), the rib (3) passes through the cylindrical structure (4.3), and the outer diameter of the second plate component (4.2) is larger than the diameter of the cylindrical structure (4.3).

4. The prestressed anchor bolt anti-buoyancy structure according to claim 3, characterized in that, The cylindrical structure (4.3) has through holes (4.7) on its sidewall.

5. The prestressed anchor bolt anti-buoyancy structure according to claim 3, characterized in that, The outer wall of the cylindrical structure (4.3) is fixedly provided with studs (4.3.1).

6. A prestressed anchor bolt anti-buoyancy structure according to claim 1 or 2, characterized in that, The connector consists of several columns (4.4), and the cross-section of the columns (4.4) is circular, square, T-shaped, elliptical, trapezoidal or polygonal.

7. A prestressed anchor bolt anti-buoyancy structure according to claim 6, characterized in that, The connector also includes a crossbar (4.5) that connects the two columns (4.4).

8. A prestressed anchor bolt anti-buoyancy structure according to claim 6, characterized in that, The top and bottom of the column (4.4) are provided with reinforcing ribs (4.8).

9. A prestressed anchor bolt anti-buoyancy structure according to claim 1, characterized in that, The reinforcing bar (3) is made of steel strand or threaded steel.

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