A pressure-type prestressed anti-buoyancy anchor and its construction method

Abstract

This invention relates to the field of building engineering technology, and particularly to a pressure-type prestressed anti-buoyancy anchor bolt, comprising a threaded steel bar, and an anchoring device, a pre-tightening device, a water-stop ring, a prefabricated bracket, a load-bearing body, and an end cap connected from top to bottom along the threaded steel bar. The anchoring device, pre-tightening device, prefabricated bracket, load-bearing body, and end cap are detachably connected to the threaded steel bar, and the water-stop ring is fixed at the borehole opening. A steel pipe is installed between the pre-tightening device and the prefabricated bracket, and a pressure-bearing anchoring section is formed between the load-bearing body and the cushion layer. This invention only requires the installation of a steel pipe within a certain depth range at the borehole opening, and the prestress can be balanced by the adhesion between the steel pipe and the grouting body interface. It does not have high requirements for the construction quality of the borehole opening, and greatly simplifies the prestressing application process.

Description

Technical Field

[0001] This invention relates to the field of building engineering technology, and in particular to a pressure-type prestressed anti-buoyancy anchor and its construction method. Background Technology

[0002] In the field of anti-buoyancy anchors in underground engineering, pressure-type anchors are also widely used as a type of anti-buoyancy anchor. However, because the reinforcing bars of pressure-type anchors must be completely unbonded, meaning the reinforcing bars are isolated from the grout, the elastic deformation of the reinforcing bars is significant when the anchor is subjected to tension. Combined with the shear deformation at the interface between the anchor body and the soil, this results in a significant increase in the tensile deformation at the anchor end. Therefore, when using pressure-type anchors for anti-buoyancy, pre-tensioning of the anchor body is necessary to eliminate elastic deformation in the anchor body.

[0003] In order to pre-tension the pressure-type anti-buoyancy anchor, the main method currently used is to set steel pads and steel blocks at the borehole opening. After tensioning the steel bars, nuts are used to lock them onto the steel pads or steel blocks. However, the above method has the following serious problems in actual engineering: (1) There is a lot of laitance at the anchor hole opening, and the mud content is often relatively high, which leads to a significant reduction in the strength of the grout at the hole opening. The compressive bearing capacity of the grout is lower than or even far lower than the design value of the compressive strength, which cannot meet the pre-tensioning requirements. (2) The soil at the hole opening is often softened by mud during construction. Due to the impact of the construction period, the strength of the soil at the hole opening is very low during pre-tensioning, forming a weak layer, which cannot meet the pre-tensioning requirements of the anti-buoyancy anchor. (3) Because the laitance and soil strength at the anchor hole opening are very low and cannot meet the pre-tensioning requirements of the anti-buoyancy anchor, the locking tension value of the pre-tensioning cannot meet the design requirements during actual construction on site. The pre-tensioning is ineffective and brings serious safety hazards to the project. Therefore, when using prestressed anti-buoyancy anchors, new technologies and methods must be developed or used to solve the problem of applying prestress to the anti-buoyancy anchors.

[0004] Based on this, in order to solve the problem of applying prestress to anti-buoyancy anchor bolts, this technical solution was invented. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a pressure-type prestressed anti-buoyancy anchor bolt, comprising a threaded steel bar, and an anchoring device, a pre-tightening device, a water-stop ring, an assembled bracket, a bearing body, and an end cap connected from top to bottom along the threaded steel bar. The anchoring device, pre-tightening device, assembled bracket, bearing body, and end cap are detachably connected to the threaded steel bar, and the water-stop ring is fixed to the drilled hole. A steel pipe is provided between the pre-tightening device and the assembled bracket, and an isolation sleeve is provided between the pre-tightening device and the bearing body. A pressure-bearing anchoring section is formed between the bearing body and the cushion layer.

[0006] This invention also provides a construction method for a pressure-type prestressed anti-buoyancy anchor, comprising the following steps:

[0007] S11. Anchor bolt fabrication: Install the bearing body and end cap at the bottom of the threaded steel bar in sequence, install the isolation sleeve and spiral reinforcement above the bearing body, and then install the prefabricated bracket to lock the threaded steel bar and isolation sleeve.

[0008] S12. Grouting pipe installation: The first grouting pipe and the second grouting pipe are installed through the bottom of the bearing body into the end cap. The first grouting pipe and the second grouting pipe are fixed by being tied at intervals with finely rolled threaded steel bars.

[0009] S13. Drilling and grouting: Drill holes at the preset positions to the preset elevation. Insert the processed anchor rods into the holes to the preset depth. Fit a water-stop ring at the hole opening, so that the ring plate of the water-stop ring rests on the pad layer. Insert a steel pipe from the top of the threaded steel bar. After the steel pipe passes through the upper and lower ring holes of the water-stop ring, it abuts against the prefabricated bracket and protrudes from the upper ring pipe of the water-stop ring. Grout is injected into the hole through the first grouting pipe. Grouting is stopped after grout continuously returns from the hole opening. After the design time interval is reached after the first grouting is completed, a second grouting is performed through the second grouting pipe.

[0010] S14. Prestressing tensioning: After the grouting body reaches the design requirements, a pre-tightening device is fitted on the top of the threaded steel bar. Then, a reaction frame is installed on the pad. The threaded steel bar is tensioned by using a through-hole jack. After the tension reaches the design requirements, the pre-tightening device is locked downwards.

[0011] S15. For the base slab construction, a waterproof membrane is laid on the cushion layer to form a waterproof layer, and the waterproof membrane overlaps on the ring plate of the water-stop ring; then a protective layer is poured on the waterproof membrane, followed by the installation of anchoring devices, and then the base slab construction is carried out.

[0012] Compared with the prior art, the pressure-type prestressed anti-buoyancy anchor provided by the present invention has the following advantages:

[0013] (1) Simplify the prestressing application process. Traditional methods use steel plates or steel blocks to apply prestress, which requires high flatness of the anchor bolt hole and special steel blocks. The technology of this invention only requires the installation of steel pipes within a certain depth range of the hole, and the prestress can be balanced by the adhesion between the steel pipe and the grouting body interface. The construction quality requirements of the hole are not high, which greatly simplifies the prestressing application process.

[0014] (2) The quality is more reliable. Traditional prestressing application methods mainly rely on the bearing capacity of the grout and soil at the bottom of the bearing plate or pier to balance the prestress. However, due to the floating grout at the borehole and the softening of the soil at the borehole, the bearing capacity cannot meet the requirements of the prestress after pretensioning and locking, resulting in a high risk of accidents. The method of the present invention relies on the bonding force at the interface between the steel pipe and the grout at the borehole to balance the prestress. Moreover, the diameter and length of the steel pipe can be adjusted according to the magnitude of the prestress, ensuring sufficient reaction force to balance the prestress. Furthermore, the bonding force at the interface between the steel pipe and the grout is very high, which easily meets the design requirements. Therefore, the quality of prestressing applied using the method of the present invention is more reliable. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a perspective view of a forged and cast integrated support body with a circular through-hole, as provided in Embodiment 1 of the present invention.

[0017] Figure 2 This is a top view of a forged and cast integrated support body with a circular through-hole, as provided in Embodiment 1 of the present invention.

[0018] Figure 3 A bottom view of a forged and cast integrated support body with a circular through-hole provided in Embodiment 1 of the present invention;

[0019] Figure 4 This is a cross-sectional view of a forged and cast integrated support body with a circular through-hole, as provided in Embodiment 1 of the present invention.

[0020] Figure 5 This is a side view of a forged and cast integrated support body with a circular through-hole, as provided in Embodiment 1 of the present invention.

[0021] Figure 6 This is another perspective view of the forged and cast integrated support body with a circular through-hole provided in Embodiment 1 of the present invention.

[0022] Figure 7 This is a top view of a welded integrated support body with a circular through-hole, as provided in Embodiment 2 of the present invention.

[0023] Figure 8 A bottom view of a welded integrated support body with a circular through-hole, provided in Embodiment 2 of the present invention;

[0024] Figure 9This is a cross-sectional view of a welded integrated support body with a circular through-hole, provided in Embodiment 2 of the present invention.

[0025] Figure 10 This is a perspective view of a welded integrated support body with a circular through-hole, as provided in Embodiment 2 of the present invention.

[0026] Figure 11 This is a top view of the welded integrated support body with a semi-circular notch for the pipe hole provided in Embodiment 3 of the present invention;

[0027] Figure 12 This is a bottom view of the welded integrated support body with a semi-circular notch for the pipe hole provided in Embodiment 3 of the present invention;

[0028] Figure 13 This is a front view of a welded integrated support body with a semi-circular notch for the pipe hole provided in Embodiment 3 of the present invention;

[0029] Figure 14 This is a left view of the welded integrated support body with a semi-circular notch for the pipe hole provided in Embodiment 3 of the present invention;

[0030] Figure 15 This is a perspective view of a welded integrated support body with a semi-circular notch for the pipe hole provided in Embodiment 3 of the present invention.

[0031] Figure 16 This is a structural schematic diagram of a pressure-type prestressed anti-buoyancy anchor provided in Embodiment 4 of the present invention;

[0032] Figure 17 for Figure 1 Section 1-1;

[0033] Figure 18 for Figure 1 Section 2-2;

[0034] Figure 19 for Figure 1 Section 3-3;

[0035] Figure 20 for Figure 1 Section 4-4;

[0036] Figure 21 for Figure 1 Section 5-5;

[0037] Figure 22 This is a schematic diagram of the anchoring device provided in Embodiment 4 of the present invention;

[0038] Figure 23 This is a front view of the equal-diameter water-stop ring with the same diameter as the upper and lower ring pipes provided in Embodiment 4 of the present invention.

[0039] Figure 24 This is a top view of the water-stop ring provided in Embodiment 4 of the present invention;

[0040] Figure 25 This is a front structural diagram of a variable diameter waterstop ring with an upper ring pipe diameter smaller than the lower ring pipe diameter provided in Embodiment 4 of the present invention.

[0041] Figure 26 This is a front structural diagram of the sleeve-type water-stop ring without the sleeve pipe installed according to Embodiment 4 of the present invention;

[0042] Figure 27 A front view of the sleeve-type water-stop ring provided in Embodiment 4 of the present invention.

[0043] Figure 28 This is a right view of the sleeve-type waterstop ring installed in Embodiment 4 of the present invention.

[0044] Figure 29 This is a front view of the sleeve-type waterstop ring installed in Embodiment 4 of the present invention.

[0045] Figure 30 This is a cross-sectional view of the end cap provided in Embodiment 4 of the present invention;

[0046] Figure 31 for Figure 20 AA cross-section view;

[0047] Figure 32 for Figure 20 BB cross-section;

[0048] Figure 33 for Figure 20 CC cross-section;

[0049] Figure 34 This is a top view of the assembled bracket provided in Embodiment 4 of the present invention;

[0050] Figure 35 This is a bottom view of the assembled bracket provided in Embodiment 4 of the present invention;

[0051] Figure 36 This is a top view of the first support member provided in Embodiment 4 of the present invention;

[0052] Figure 37 This is a front view of the assembled bracket provided in Embodiment 4 of the present invention;

[0053] Figure 38 This is a rear view of the assembled bracket provided in Embodiment 4 of the present invention.

[0054] Figure label:

[0055] Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0058] Example 1

[0059] This embodiment provides an integrated carrier 220, such as Figures 1 to 3 As shown, in this embodiment, the horizontal cross-section of the bearing cap 222 is circular, and the bearing plate 221 and the bearing cap 222 are integrally formed. In specific implementation, it can be integrally formed by forging and casting. After the bearing cap 222 is installed on the reinforcing bar, the connection force with the reinforcing bar is not less than the ultimate pull-out bearing capacity of the anchor rod used in the bearing body. Preferably, in this embodiment, the through hole 224 is a circular hole located near the edge of the bearing plate 221, or it can be a semi-circular hole located at the edge of the bearing plate 221.

[0060] In addition, in order to enhance the pull-out bearing capacity of the bearing, the existing bearing has stiffening ribs installed at the bottom of the bearing plate 221. However, the existing technology welds the external stiffening ribs to the bearing plate 221, which also causes the bearing to have a complicated production process.

[0061] To solve this technical problem, the present invention provides a reinforcing cone 226 at the bottom of the support plate 221, such as... Figures 4 to 5As shown, the vertical height of the reinforcing cone 226 increases linearly with a predetermined slope from the edge of the bearing plate 221 to the bearing cap 222, giving the bottom of the bearing plate 221 a slope. The reinforcing cone 226 is integrally formed with the bearing plate 221 and the bearing cap 222. By setting the reinforcing cone 226, the pull-out bearing capacity of the bearing body is improved. At the same time, the reinforcing cone 226 is set at the bottom of the bearing plate 221 and integrally formed with the bearing plate 221 and the circular bearing cap 222. Specifically, it can be integrally formed by forging and casting.

[0062] Preferably, such as Figure 6 As shown, the inner wall of the third through hole 223 of the bearing plate 221 and the bearing cap 222 is provided with continuous internal threads 225. Specifically, the outer surface of the fine-rolled threaded steel bar installed on the bearing body is provided with external threads, and the interior of the third through hole 223 is provided with matching internal threads 225. The external threads on the outer surface of the threaded steel bar are threadedly connected with the internal threads 225 inside the third through hole 223, ensuring the stability of the bearing body installation.

[0063] Example 2

[0064] This embodiment provides an integrated, one-piece carrier 220, such as... Figure 7 , Figure 8 and Figure 9 As shown, it includes a fixedly connected support plate 221 and support cap 222. The plane of the support plate 221 is perpendicular to the axial normal of the support cap 222. The support plate 221 and the support cap 222 are provided with a third through hole 223. The horizontal cross section of the support plate 221 is circular. The surface of the support plate 221 is provided with a through hole 224.

[0065] In specific implementation, the horizontal cross section of the bearing plate 221 is circular, and the bearing body is fixed to the threaded steel bar through the third through-bar hole 223. The bearing plate 221 is set upwards facing the drill hole opening. The area of ​​the circular bearing plate 221 is large enough, so through-bar holes 224 can be set on the surface of the bearing plate 221 to facilitate the installation of the grouting pipe.

[0066] In one embodiment, there are two through holes 224. Specifically, in actual construction, only two grouting pipes are generally installed for grouting, but the number can be adjusted according to the number of grouting pipes. Optionally, the through holes 224 can be symmetrically arranged around the center of the bearing plate 221, or they can be arranged without symmetry.

[0067] In one embodiment, such as Figure 8 and Figure 10As shown, the horizontal cross-section of the bearing cap 222 is hexagonal, and the bearing plate 221 is welded to the bearing cap 222. Specifically, the bearing cap 222 is a nut with a hexagonal cross-section, which is welded to the circular bearing plate 221 to form an integrated bearing body 220. At this time, an internal thread 225 is provided inside the third through hole 223 of the bearing cap 222 to match the external thread of the threaded steel bar. The hexagonal nut has the same strength as the threaded steel bar. After the bearing cap 222 is installed on the steel bar, the connection force between the bearing cap 222 and the steel bar is not less than the ultimate pull-out bearing capacity of the anchor rod used in the bearing body.

[0068] Preferably, such as Figures 7 to 10 As shown, the through hole 224 is a circular hole located near the edge of the support plate 221.

[0069] Example 3

[0070] In this embodiment, the through hole 224 is a semi-circular hole located at the edge of the support plate 221. Specifically, as shown... Figures 11 to 15 As shown, the through hole 224 is a semi-circular notch set at the boundary of the bearing plate 221. When the construction period is very tight, the grouting pipe can be directly clamped on the semi-circular notch for quick binding and fixing. The horizontal cross section of the bearing cap 222 is hexagonal.

[0071] The remaining structure is the same as that in Embodiment 1, and will not be described again here.

[0072] Example 4

[0073] This invention provides a pressure-type prestressed anti-buoyancy anchor bolt, such as... Figures 16 to 21 As shown, it includes a threaded steel bar 110, and an anchoring device 200, a pre-tightening device 210, a water-stop ring 240, an assembled bracket 260, an integrated bearing body 220, and an end cap 250 connected from top to bottom along the threaded steel bar 110. The anchoring device 200, the pre-tightening device 210, the assembled bracket 260, the integrated bearing body 220, and the end cap 250 are detachably connected to the threaded steel bar 110, and the water-stop ring 240 is fixed to the drill hole 104.

[0074] A steel pipe 112 is installed between the pre-tightening device 210 and the assembled bracket 260, and an isolation sleeve 111 is installed between the pre-tightening device 210 and the integrated bearing body 220. A pressure-bearing anchoring section 108 is formed between the integrated bearing body 220 and the pad layer 103. Specifically, both ends of the isolation sleeve 111 are sealed.

[0075] In one embodiment, such as Figure 22As shown, the anchoring device 200 includes a first nut 201 and a first steel pad 202. The first steel pad 202 is vertically connected to the first nut 201. The first steel pad 202 and the first nut 201 have a communicating first through hole 203. The inner wall of the first through hole 203 forms an internal thread 225, which is threaded to be adapted to the external thread of the threaded steel bar 110.

[0076] In one embodiment, the pre-tightening device 210 includes a second nut 211 and a second steel pad 212. The second steel pad 212 is perpendicularly connected to the second nut 211. The second steel pad 212 and the second nut 211 have a communicating second through hole 213. The inner wall of the second through hole 213 forms an internal thread 225, which is threaded to be adapted to the external thread of the threaded steel bar 110.

[0077] In one embodiment, the carrier is the integrated carrier 220 described in any of the embodiments of Embodiment 1, Embodiment 2 and Embodiment 3, which has the same structure and will not be described again here.

[0078] In one embodiment, a spiral rib 113 is sleeved on the outer side of the integrated support body 220. The diameter of the spiral rib 113 is greater than the longest length of the support plate 221 of the integrated support body 220. The spiral rib 113 is used to laterally or radially constrain the grouting body 105. Specifically, the spiral rib 113 is sleeved on the outer side of the integrated support body 220 of the present invention, and the diameter of the spiral rib 113 is greater than the longest length of the support plate 221 of the integrated support body 220. Preferably, the integrated support body 220 of the present invention is a circular integrated support body 220, and the diameter of the spiral rib 113 is greater than the diameter of the integrated support body 220. When the cross-section of the support plate 221 is elliptical, the diameter of the spiral rib 113 is greater than the length of the major axis of the integrated support body 220.

[0079] Specifically, since the top surface of the bearing plate 221 of the integrated bearing body 220 is a slope or sphere symmetrical along its long axis, it will cause a splitting effect on the grouting body 105 when it is squeezed. The spiral reinforcement 113 sleeved on the outside of the integrated bearing body 220 will generate a strong lateral or radial restraint effect on the grouting body 105, significantly improving the compressive bearing capacity of the grouting body 105, thereby fully ensuring the coordinated bearing of the pressure-bearing anchor section 108 and the tension-bearing anchor section 109, and greatly improving the pull-out bearing capacity of the tension-compression composite anti-buoyancy anchor.

[0080] In one embodiment, the water-stop ring 240 includes an upper ring pipe 241, a lower ring pipe 242, and a ring plate 243. The upper ring pipe 241 is located above the ring plate 243, and the lower ring pipe 242 is located below the ring plate 243. The ring plate 243 has a ring plate hole 243a. The upper ring pipe 241 and the lower ring pipe 242 are hollow to form an upper ring hole 241a and a lower ring hole 242a. The normal axes of the upper ring hole 241a, the ring plate hole 243a, and the lower ring hole 242a coincide.

[0081] Specifically, when the normal axes coincide, the plane of the ring plate 243 is perpendicular to the upper ring pipe 241 and the lower ring pipe 242. The water-stop ring 240 is embedded between the base plate 100 and the borehole 104, and a cushion layer 103 is also provided between the base plate 100 and the borehole 104. The ring plate 243 abuts against the cushion layer 103. The anchor rod 110 passes through the upper ring hole 241a, the ring plate hole 243a, and the lower ring hole 242a and is placed inside the borehole 104. The sidewalls of the upper ring pipe 241 and the lower ring pipe 242 effectively prevent groundwater from seeping between the base plate 100 and the cushion layer 103, and between the cushion layer 103 and the soil layer of the borehole 104, thus avoiding corrosion of the reinforcing steel.

[0082] Better, such as Figures 23 to 25 As shown, the diameter of the upper annular hole 241a is the same as the diameter of the annular plate hole 243a and the lower annular hole 242a, or the diameter of the upper annular hole 241a is smaller than the diameter of the annular plate hole 243a and the lower annular hole 242a.

[0083] In one embodiment, the water-stop ring 240 is further provided with a collar tube 244, which is installed outside the upper ring tube 241, such as... Figure 26 As shown, the upper ring pipe 241 is symmetrically provided with suspension rod mounting grooves 245, such as... Figure 27 As shown, the collar tube 244 has symmetrically opened lifting rod cover holes 246, and the lifting rod cover holes 246 are arranged opposite to the lifting rod placement groove 245.

[0084] In practice, the required diameter of the anchor bars 110 varies considerably, and different geological environments require different diameters of the anchor bars 110. Therefore, a hanging bar placement groove 245 is opened in the upper ring pipe 241. The hanging bar placement groove 245 abuts against the ring plate 243. The width of the hanging bar placement groove 245 can match the requirements of different anchor bar diameters 110, so that the horizontal hanging bars 247 can be stably installed and pressed against the ring plate 243. Preferably, the shape of the hanging bar placement groove 245 is rectangular, as the rectangular shape is more conducive to the placement of the anchor bars 110.

[0085] In one embodiment, such as Figure 28 , Figure 29As shown, the sleeve 244 is fitted over the upper sleeve 241 and is detachably connected to the waterstop ring 240. The sleeve 244 includes mutually perpendicular horizontal plates 244a and vertical plates 244b. The lifting bar cover hole 246 is opened at the bottom of the vertical plate 244b. The opening of the lifting bar cover hole 246 can perfectly match the cross-section of the horizontal lifting bar 247. The distance between the lifting bar cover holes 246 can be determined according to the diameter of the anchor bar 110. The lifting bar placement groove 245 of the upper sleeve 241 cooperates with the lifting bar cover hole 246 of the sleeve 244, which can meet the installation requirements of different types of reinforcing bars. Furthermore, it eliminates the need for additional molds for the upper sleeve 241; only the sleeve 244 needs to be produced according to different requirements, greatly reducing costs.

[0086] Preferably, such as Figure 27 As shown, the shape of the lifting bar cover hole 246 is either channel-shaped or semi-circular. Specifically, the cross-section of the anchor bar 110 is generally circular, and setting the lifting bar cover hole 246 to be channel-shaped or semi-circular can better accommodate the anchor bar 110.

[0087] In one embodiment, such as Figures 30 to 33 As shown, the end cap 250 includes a ball head 253, a threaded groove 251, flexible blades 254, and stiffening ribs 252. The ball head 253 is a hollow hemisphere. Two flexible blades 254 are connected to the upper part of the ball head 253. The horizontal cross-sectional diameter of the flexible blades 254 gradually increases upward. The cross-section of the ball head 253 and the flexible blades 254 after connection is "U". The threaded groove 251 is located at the inner center of the ball head 253. A stiffening rib 252 is provided between the ball head 253 and the threaded groove 251. The stiffening ribs 252 are symmetrically arranged around the threaded groove 251 at preset angles.

[0088] In one embodiment, such as Figures 34 to 38 As shown, the assembled bracket 260 includes a first bracket 260a, a second bracket 260b, and a connector 267. The first bracket 260a and the second bracket 260b are symmetrical in shape, and the connector 267 symmetrically and detachably connects the first bracket 260a and the second bracket 260b. Both the first bracket 260a and the second bracket 260b include an end face 261 and a rib arc surface 265. The rib arc surface 265 is perpendicularly connected to the bottom of the end face 261. The rib arc surface 265 of the first bracket 260a and the rib arc surface 265 of the second bracket 260b are spliced ​​to form a rib groove, which is located at the center of the spliced ​​end faces 261 of the first bracket 260a and the second bracket 260b.

[0089] In specific implementation, a semi-circular ribbed surface 265 of a certain length is provided at the bottom of the end face 261. The ribbed surface 265 of the first support member 260a and the ribbed surface 265 of the second support member 260b are spliced ​​to form a rib groove for placing the threaded steel bar 110, which is set at the center of the end face 261. The split first support member 260a and the second support member 260b are symmetrical in shape. When it is necessary to install the assembled support 260, the first support member 260a and the second support member 260b are directly spliced ​​at the designed position of the assembled support 260 of the threaded steel bar 110. The ribbed surface 265 is fastened to the threaded steel bar 110. The first support member 260a and the second support member 260b are symmetrically and detachably connected by the connector 267, which greatly simplifies the construction intensity and avoids damage to the anti-corrosion coating of the threaded steel bar 110.

[0090] Preferably, the shape of the end faces 261 of the first support member 260a and the second support member 260b after splicing is elliptical. Specifically, the elliptical shape of the end faces 261 of the first support member 260a and the second support member 260b after splicing reduces the cross-sectional area of ​​the assembled support 260 inside the drill hole 104, increases the area of ​​the gap between the end face 261 and the drill hole 104, and avoids an excessively large cross-section from obstructing the grouting body 105.

[0091] In one embodiment, the prefabricated bracket 260 is further provided with two pipe grooves 266. The pipe grooves 266 are semi-circular notches and are symmetrically arranged along the major axis of the elliptical end face 261 after the first bracket 260a and the second bracket 260b are joined. Specifically, in actual construction, the pipe grooves 266 allow the grouting pipes to pass through. The number of grouting pipes is generally two, so the two pipe grooves 266 can meet most construction needs. The number of pipe grooves 266 can also be designed according to specific circumstances and is not limited to two. The semi-circular notch shape of the pipe grooves 266 can be well adapted to the shape of the grouting pipes. When the grouting pipes are installed, the pipe grooves 266 engage with the grouting pipes, ensuring the overall installation direction of the grouting pipes and guaranteeing the accuracy of the grouting pipe installation position.

[0092] In one embodiment, the inside of the rib groove 264 is provided with a rib groove that matches the threaded steel bar 110. Specifically, the rib groove 264 of the assembled bracket 260 has a rib groove inside, which is adapted to the rib of the threaded steel bar 110. The adaptation of the rib groove inside the rib groove 264 to the rib of the threaded steel bar 110 ensures the firmness of the assembled bracket 260 installed on the threaded steel bar 110.

[0093] In one embodiment, such as Figure 37 and Figure 38As shown, the first support member 260a and the second support member 260b each include two locking surfaces 262, which are respectively connected to the two sides of the rib arc surface 265. The top of the locking surface 262 is connected to the bottom of the end face 261. At least one locking hole 263 is provided on the locking surface 262. The locking holes 263 of the first support member 260a and the second support member 260b are positioned opposite each other. The connecting member 267 passes through the locking holes 263 of the first support member 260a and the second support member 260b to symmetrically and detachably connect the first support member 260a and the second support member 260b.

[0094] In one embodiment, the connector 267 includes a screw rod 267a and a nut 267b.

[0095] In specific implementation, the first support member 260a and the second support member 260b are installed on the threaded steel bar 110 from both sides, so that the rib grooves on the inner walls of the rib grooves 264 of the first support member 260a and the second support member 260b match the ribs on the outer walls of the threaded steel bar 110. At the same time, the locking holes 263 of the first support member 260a and the second support member 260b are aligned. The locking holes 263 of the first support member 260a and the second support member 260b are connected by a screw rod 267a. The first support member 260a and the second support member 260b are then tightened with a nut 267b to form a complete assembled support 260. This splicing installation from both sides of the threaded steel bar 110 achieves efficient installation of the assembled support 260, while avoiding damage to the anti-corrosion coating on the surface of the threaded steel bar 110.

[0096] Example 5

[0097] This invention also provides a construction method for a pressure-type prestressed anti-buoyancy anchor, comprising the following steps:

[0098] S11, Anchor rod fabrication: Install an integrated bearing body 220 and an end cap 250 sequentially at the bottom of the threaded steel bar 110, install an isolation sleeve 111 and a spiral bar 113 above the integrated bearing body 220, and then install an assembled bracket 260 to lock the threaded steel bar 110 and the isolation sleeve 111.

[0099] In this embodiment, the integrated support body 220 is preferably a circular integrated support body 220. Since an isolation sleeve 111 needs to be installed between the circular integrated support body 220 and the pre-tightening device 210, but the pre-tightening device 210 is installed after grouting, the isolation sleeve 111 needs to be installed before the integrated support body 220 is installed, and the isolation sleeve 111 needs to be locked with the prefabricated bracket 260 to facilitate subsequent construction procedures.

[0100] S12. Grouting pipe installation: The first grouting pipe 106 and the second grouting pipe 107 are passed through the bottom of the integrated bearing 220 and installed into the end cap 250. The first grouting pipe 106 and the second grouting pipe 107 are fixed by being tied at intervals with finely rolled threaded steel bars 110.

[0101] In practice, the first grouting pipe 106 and the second grouting pipe 107 pass through the third through hole 223 of the integrated bearing 220 and abut against the inner wall of the flexible blade 254 of the end cap 250. In order to ensure that the first grouting pipe 106 and the second grouting pipe 107 do not shake and to facilitate installation, the first grouting pipe 106 and the second grouting pipe 107 are tied together at intervals using precision threaded steel bars 110.

[0102] S13. Grouting of borehole 104: Borehole 104 is drilled at a preset position. After borehole 104 reaches the preset elevation, the processed anchor rod is inserted into borehole 104 to the preset depth. A water-stop ring 240 is fitted into the borehole opening, so that the ring plate 243 of the water-stop ring 240 rests on the pad layer 103. A steel pipe 112 is fitted from the top of the threaded steel bar 110. The steel pipe 112 passes through the upper ring hole 241a and the lower ring hole 242a of the water-stop ring 240 and abuts against the prefabricated bracket 260, and protrudes from the upper ring pipe 241 of the water-stop ring 240. Grouting is performed into borehole 104 through the first grouting pipe 106. Grouting is stopped after grout continuously returns from the borehole opening. After the design time interval is reached after the first grouting is completed, a second grouting is performed through the second grouting pipe 107.

[0103] S14. Prestressing tensioning: After the strength of the grouting body 105 reaches the design requirements, the pre-tightening device 210 is fitted on the top of the threaded steel bar 110. Then, the reaction frame is installed on the pad layer 103. The threaded steel bar 110 is tensioned by using a through-hole jack. After the tension reaches the design requirements, the pre-tightening device 210 is locked downwards.

[0104] Specifically, the pre-tightening device 210 includes a second steel pad 212 and a second nut 211. The insertion sequence of the threaded steel bar 110 pre-tightening device 210 is the second steel pad 212 and the second nut 211.

[0105] S15. Construction of base slab 100: A waterproof membrane 102 is laid on the cushion layer 103 to form a waterproof layer. The waterproof membrane 102 overlaps on the ring plate 243 of the waterstop ring 240. Then, a protective layer 101 is poured on the waterproof membrane 102, followed by the installation of the anchoring device 200, and the construction of base slab 100 is carried out.

[0106] In practice, the waterproof membrane 102 is laid on the upper surface of the ring plate 243 of the waterstop ring 240 to prevent groundwater seepage. The anchoring device 200 includes a first nut 201 and a first steel washer 202. The first nut 201 and the first steel washer 202 are welded together, with the first steel washer 202 at the bottom and the first nut 201 at the top. The anchoring device 200 is used to fix the device to the top of the threaded steel bar 110, and then the base plate 100 is constructed.

[0107] Although this document frequently uses terms such as base plate, protective layer, waterproof membrane, bedding layer, borehole, grouting body, first grouting pipe, second grouting pipe, pressure-bearing anchorage section, tension-bearing anchorage section, threaded reinforcing bar, isolation sleeve, steel pipe, spiral reinforcement, anchoring device, first nut, first steel pad, first through-reinforcement hole, and pre-tightening device, the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pressure-type prestressed anti-buoyancy anchor bolt, characterized in that: It includes threaded steel bars, and anchoring devices, pre-tightening devices, steel pipes, water-stop rings, prefabricated brackets, isolation sleeves, bearing bodies, and end caps connected from top to bottom along the threaded steel bars. The anchoring devices, pre-tightening devices, prefabricated brackets, bearing bodies, and end caps are detachably connected to the threaded steel bars, and the water-stop rings are fixed to the drilled holes. A steel pipe is provided between the pre-tightening device and the assembled bracket, and an isolation sleeve is provided between the pre-tightening device and the bearing body. A pressure-bearing anchoring section is formed between the bearing body and the pad layer. The water-stop ring includes an upper ring pipe, a lower ring pipe, and a ring plate. The upper ring pipe is located above the ring plate, and the lower ring pipe is located below the ring plate. The ring plate has a ring plate hole. The upper ring pipe and the lower ring pipe are hollow to form an upper ring hole and a lower ring hole, respectively. The normal axes of the upper ring hole, the ring plate hole, and the lower ring hole coincide. The water-stop ring is also provided with a sleeve tube, which is installed on the outside of the upper ring tube. The upper ring tube is symmetrically provided with suspension rod placement grooves, and the sleeve tube is symmetrically provided with suspension rod cover holes. The suspension rod cover holes are arranged opposite to the suspension rod placement grooves. The assembled bracket includes a first bracket, a second bracket, and a connector. The first bracket and the second bracket are symmetrical in shape, and the connector symmetrically and detachably connects the first bracket and the second bracket. Both the first and second support members include an end face and a ribbed arc surface, with the ribbed arc surface perpendicularly connected to the bottom of the end face. The ribbed arc surface of the first and second support members are spliced ​​together to form a rib groove, which is located at the center of the spliced ​​end faces of the first and second support members. The spliced ​​end faces of the first and second support members are elliptical in shape. The assembled support for the anti-buoyancy anchor rod also includes two pipe grooves, which are semi-circular notches symmetrically arranged along the major axis of the elliptical end face of the spliced ​​first and second support members. The first and second support members each include two locking surfaces, which are respectively connected to both sides of the ribbed arc surface. Each locking surface has at least one locking hole, with the locking holes of the first and second support members positioned opposite each other. A connector passes through the locking holes of the first and second support members to symmetrically and detachably connect the first and second support members.

2. The pressure-type prestressed anti-buoyancy anchor bolt according to claim 1, characterized in that: The outer side of the carrier is fitted with a spiral rib, the diameter of which is greater than the longest length of the carrier plate. The spiral rib is used to radially constrain the grouting body.

3. The pressure-type prestressed anti-buoyancy anchor bolt according to claim 1, characterized in that: The inner wall of the reinforcing groove is provided with rib grooves that match the threaded reinforcing bars.

4. A construction method using pressure-type prestressed anti-buoyancy anchors as described in any one of claims 1 to 3, characterized in that, Includes the following steps: S11. Anchor rod fabrication: Install the bearing body and end cap at the bottom of the threaded steel bar in sequence, install the spiral reinforcement and isolation sleeve above the bearing body, and then install the prefabricated bracket at the designed position. S12. Grouting pipe installation: The first grouting pipe and the second grouting pipe are installed through the bottom of the bearing body into the end cap. The first grouting pipe and the second grouting pipe are fixed by being tied at intervals with finely rolled threaded steel bars and fixed on the prefabricated bracket. S13. Drilling and grouting: Drill a hole at a preset position to a preset elevation. Insert the processed anchor rod into the hole to a preset depth. Fit a water-stop ring at the hole opening, so that the ring plate of the water-stop ring rests on the pad layer. Insert a steel pipe from the top of the threaded steel bar. After the steel pipe passes through the upper and lower ring holes of the water-stop ring, it abuts against the assembled bracket and protrudes from the upper ring pipe of the water-stop ring. Grout is injected into the hole through the first grouting pipe. Grouting is stopped after grout continuously returns from the hole opening. After the design time interval is reached after the first grouting is completed, a second grouting is performed through the second grouting pipe. S14. Prestressing tensioning: After the grout strength reaches the design requirements, a pre-tightening device is fitted on the top of the threaded steel bar. Then, a reaction frame is installed on the pad layer. The threaded steel bar is tensioned by using a through-hole jack. After the tension reaches the design requirements, the pre-tightening device is locked downwards. S15. Base slab construction: A waterproof membrane is laid on the cushion layer to form a waterproof layer, and the waterproof membrane overlaps the ring plate of the water-stop ring; then a protective layer is poured on the waterproof membrane, followed by the installation of anchoring devices, and the base slab construction is carried out.

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