Construction method of one-time pre-embedded vertical prestressed basement outer wall

Abstract

The application discloses a construction method of a one-time embedded vertical prestressed force basement outer wall, which comprises the following steps: 1, setting up a tendon platform; 2, embedding a prestressed tendon; 3, pouring the basement outer wall; and 4, stretching the prestressed tendon. The prestressed tendon is embedded before the construction of the basement outer wall, vertical prestressed tendons are constructed in the outer wall, the prestressed tendon is integrated with the outer wall, the performance of the outer wall is improved, the building life is prolonged, the temperature deformation and crack resistance of the outer wall are reduced, and the seismic performance of the building is improved.

Description

Technical Field

[0001] This invention belongs to the field of wall prestressing tendon technology, specifically relating to a method for constructing basement exterior walls with one-time pre-embedded vertical prestressing. Background Technology

[0002] Currently, bonded prestressing has been applied in many areas, but primarily in large-span structures such as beams and slabs, with prestressing tendons typically arranged horizontally within concrete members. Its application in vertical members is relatively limited, mainly in basement exterior walls and frame columns. With increasingly scarce land available for construction, especially in urban centers, the excavation boundaries are significantly restricted by surrounding buildings, municipal roads, and urban pipe networks. To ensure sufficient building space, the net space of the foundation pit is compressed. Deep foundation pit projects also face challenges such as complex geological conditions, high groundwater levels, high bearing capacity requirements, and complex surrounding building environments. Therefore, there is a lack of a method for constructing basement exterior walls with one-time pre-embedded vertical prestressing, a rationally designed and simple method that integrates the prestressing tendons with the basement exterior wall for unified operation. Summary of the Invention

[0003] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing a method for constructing basement exterior walls with one-time pre-embedded vertical prestressing tendons. By pre-embedding prestressing tendons before constructing the basement exterior walls, vertical prestressing tendons are constructed within the exterior walls, making the prestressing tendons and exterior walls an integral whole. This improves the performance of the exterior walls, extends the building's lifespan, reduces temperature deformation and cracking of the exterior walls, improves the building's seismic performance, and facilitates widespread use.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a construction method for basement exterior walls with one-time pre-embedded vertical prestressing, characterized in that the method includes the following steps:

[0005] Step 1: Construct the lifting platform:

[0006] Step 101: Erecting the cable tower: Lay the first channel steel under the upper reinforcement of the raft foundation, lay the second channel steel above the upper reinforcement of the raft foundation, fix the vertical trestles under the second channel steel, the first channel steel and the second channel steel are arranged in a grid pattern, install the adjusting base support at multiple intersections of the first channel steel and the second channel steel, fix the vertical support pipe on the adjusting base support, install the cable tower on the vertical support pipe, and then lay steel plates on the cable tower to form a slack rail platform;

[0007] Step 102, Tie the reinforcing bar platform: Install wall ties on the foundation pit wall, and then fix horizontal steel pipes on the wall ties. The horizontal steel pipes are connected to the vertical steel pipes of the cable tower through fasteners.

[0008] Step 2: Embed prestressing tendons:

[0009] Step 201, Anchoring the fixed end of the prestressed tendon: Seal the fixed end of the prestressed tendon into the extrusion anchor, and then connect the lower end of the longitudinal through bar in the outer wall body and the extrusion anchor to the lower reinforcement of the raft slab.

[0010] Step 202: Pouring raft slab concrete: A waterstop steel plate is installed between the bottom of the two side formworks of the outer wall. Then, concrete is poured within the design range of the raft slab to the bottom of the adjusting support to form the raft slab. The concrete inside the outer wall is poured to the middle of the waterstop steel plate to form the foundation guide wall.

[0011] Step 203: Lay prestressed tendons and tie the outer wall reinforcement: Tie multiple horizontal through bars and multiple tie bars evenly between the two rows of longitudinal through bars along the height direction of the longitudinal through bars. Then, set multiple positioning brackets at intervals on the multiple horizontal through bars. Pass the upper end of the prestressed tendon through the positioning bracket and extend it upward to the side formwork of the outer wall to the bar-laying platform. Then, tie the prestressed tendon to the longitudinal through bars and the horizontal through bars from bottom to top.

[0012] Step 204: Embedding the tensioning end of the prestressing tendon: After the prestressing tendon is laid to the designed height of the outer wall, the hidden beam reinforcement is tied to the upper part of the outer wall, and the spiral reinforcement sleeved on the prestressing tendon is installed on the hidden beam reinforcement. Then, the extruded board located on the upper part of the spiral reinforcement is inserted through the tensioning end of the prestressing tendon.

[0013] Wherein, the tensioning end of the prestressing tendon extends upward to the outside of the extruded polystyrene board, the lower end of the extruded polystyrene board is located inside the exterior wall formwork, and the upper end of the extruded polystyrene board is located outside the exterior wall formwork;

[0014] Step 3: Pour concrete between the formwork of the basement exterior walls to the designed height of the exterior walls to form the exterior walls;

[0015] Step 4: Tensioning the prestressing tendons: After the concrete strength of the outer wall reaches 90%, install the bearing pad and single-hole anchor at the tensioning end of the prestressing tendon, tension the prestressing tendon and seal the anchor. Then, pour expansion concrete on the top of the outer wall to connect the single-hole anchor of the prestressing tendon with the outer wall as one unit, and make the top of the outer wall flat.

[0016] The above-mentioned method for constructing a basement exterior wall with one-time pre-embedded vertical prestress is characterized in that: in step 101, the upper surface of the second channel steel is flush with the upper surface of the raft slab.

[0017] The above-mentioned method for constructing a basement exterior wall with one-time pre-embedded vertical prestress is characterized in that: the wall connection includes an anchor plate tightly attached to the foundation pit wall and a hinged cylinder set on the anchor plate for connecting a horizontal steel pipe, the hinged cylinder being installed on one side of the anchor plate through a hinged support, and the anchor plate being provided with expansion bolts anchored into the foundation pit wall.

[0018] The above-mentioned method for constructing a basement exterior wall with one-time pre-embedded vertical prestress is characterized in that: the positioning bracket includes a first limiting plate arranged parallel to the horizontal through bar and multiple sets of limiting units arranged between the horizontal through bar and the first limiting plate, each set of limiting units includes two parallel second limiting plates, one end of the second limiting plate is connected to the first limiting plate, and a prestressing tendon is between the two second limiting plates.

[0019] The above-mentioned method for constructing a basement exterior wall with one-time pre-embedded vertical prestressing is characterized in that: the length of the prestressing tendon... satisfy ;in, This refers to the design length of the prestressed tendons inside the exterior wall. This refers to the operational length of the prestressing tendon. This refers to the anchorage length of the prestressing tendon extending into the raft slab.

[0020] The above-mentioned method for constructing a basement exterior wall with one-time pre-embedded vertical prestressing is characterized in that: in step 202, as the laying height of the prestressing tendons increases, the height of the tendon-laying platform is moved accordingly. When the laying height of the prestressing tendons is higher than the height of the lowest structural slab, an inter-floor support frame is installed between two adjacent structural slabs. The inter-floor support frame is fixedly connected to the cable-stayed tower, and a screw rod passing through the structural slab is installed on the inter-floor support frame. Nuts that abut against the upper and lower surfaces of the structural slab are respectively threaded onto the screw rod.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. Due to the narrow spacing of the troughs and the fact that the steel waist beams on the pit walls occupy part of the space of the troughs, this invention forms a rebar-laying platform by erecting cable-stayed towers on the raft slab, which facilitates the placement of excessively long prestressed tendons and makes it easier to promote and use.

[0023] 2. This invention facilitates the integration of the bottom of the cable-stayed tower with the steel reinforcement of the raft foundation by erecting the cable-stayed tower before the raft foundation is poured, thus ensuring the stability of the cable-stayed tower. Furthermore, the invention enables the one-time pre-embedding of prestressed tendons by erecting a rebar-laying platform in the limited space of the deep foundation pit. This allows for interleaved operations without affecting the process, ensuring the placement of prestressed tendons in the outer wall, reducing the difficulty of engineering construction, and achieving good results.

[0024] 3. The method of this invention is simple and easy to operate. By pre-embedding prestressing tendons before the construction of the basement exterior walls, vertical prestressing tendons are installed in the exterior walls, making the prestressing tendons and the exterior walls an integral whole. This improves the performance of the exterior walls, extends the building's lifespan, reduces temperature deformation and cracking of the exterior walls, and improves the building's seismic performance. At the same time, the use of prestressing tendons reduces the cross-sectional dimensions of the exterior walls, reduces the amount of steel reinforcement, lowers construction costs, and facilitates widespread use.

[0025] In summary, this invention achieves the construction of vertical prestressing tendons in the exterior wall by pre-embedding them before the construction of the basement exterior wall. This integrates the prestressing tendons with the exterior wall, improving the performance of the exterior wall, extending the building's lifespan, reducing temperature deformation and cracking of the exterior wall, and enhancing the building's seismic performance. It is also convenient for widespread use.

[0026] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0027] Figure 1 This is a flowchart of the construction method of the present invention.

[0028] Figure 2 This is a schematic diagram of the cable-stayed tower structure of the present invention.

[0029] Figure 3 This is a structural schematic diagram of step 203 of the present invention.

[0030] Figure 4 This is a schematic diagram of the structure of step four of the present invention.

[0031] Figure 5 This is a structural schematic diagram of the wall-connecting component of the present invention.

[0032] Figure 6 for Figure 5 The right view.

[0033] Figure 7 This is a schematic diagram of the positioning bracket of the present invention.

[0034] Figure 8 This is a schematic diagram of the structure of the top of the outer wall in step 204 of the present invention.

[0035] Figure 9 This is a schematic diagram of the structure at the top of the outer wall in step four of the present invention.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1. Raft foundation; 2. Upper reinforcement of raft foundation; 3. First channel steel; 4. Second channel steel; 5. Reinforcing bar; 6. Adjustable bottom support; 7. Vertical support pipe; 8. Cable-stayed tower; 9. Reinforcing bar platform; 10. Excavation trench; 11. Pit wall; 12. Steel wainscoting; 13. Wall ties; 14. Lower reinforcement of raft foundation; 15. Prestressed tendons; 16. Extrusion anchors; 17. Foundation guide wall; 18. Water-stop steel plate; 19. Longitudinal through reinforcement; 20. Horizontal through reinforcement; 21. Exterior wall; 22. Structural slab; 23. Inter-floor support frame; 24. Screw rod; 25. Hidden beam reinforcement; 26. Spiral reinforcement; 27. Extruded polystyrene board; 28. Bearing pad; 29. ​​Single-hole anchor; 30. Expansion concrete; 31. First limiting plate; 32. Second limiting plate; 33. Anchor plate; 34. Expansion bolt; 35. Hinge support; 36. Hinge sleeve; 37. Horizontal steel pipe; 38. Fastener. Detailed Implementation

[0038] like Figures 1 to 9 As shown, the present invention provides a method for constructing a basement exterior wall with one-time pre-embedded vertical prestressing, comprising the following steps:

[0039] Step 1: Construct the lifting platform:

[0040] Step 101: Erecting the cable tower: Lay the first channel steel 3 below the upper reinforcing bar 2 of the raft foundation, lay the second channel steel 4 above the upper reinforcing bar 2 of the raft foundation, fix the vertical trestles 5 below the second channel steel 4, the first channel steel 3 and the second channel steel 4 are arranged in a grid pattern, install the adjusting base support 6 at multiple intersections of the first channel steel 3 and the second channel steel 4, fix the vertical support pipe 7 on the adjusting base support 6, install the cable tower 8 on the vertical support pipe 7, and then lay steel plates on the horizontal steel pipe of the cable tower 8 to form a slack rail platform 9.

[0041] During actual construction, the cable-stayed tower 8 is a double-row ground-supported scaffold. Because the spacing of the trench 10 is narrow and the steel waist beam 12 on the pit wall 11 occupies part of the space of the trench 10, the cable-stayed tower 8 is erected on the raft 1 to form a prestressing tendon platform 9, which is convenient for placing excessively long prestressing tendons 15. The prestressing tendon platform 9 is surrounded by guardrails and safety nets to prevent items on the prestressing tendon platform 9 from falling from a height and to ensure the safety of construction personnel.

[0042] Step 102, Connecting the Reinforcing Bar Platform: Install wall ties 13 on the pit wall 11, and then fix horizontal steel pipes 37 on the wall ties 13. The horizontal steel pipes 37 are connected to the vertical steel pipes of the cable tower 8 through fasteners 38.

[0043] In this embodiment, in step 101, the upper surface of the second channel steel 4 is flush with the upper surface of the raft plate 1.

[0044] In actual construction, the upper reinforcing bars 2 and side formwork of the raft slab 1 are tied first, and then the cable tower 8 is installed. The first channel steel 3, the second channel steel 4, the stirrups 5 and the adjusting base 6 are all welded together. By setting the upper surface of the second channel steel 4 to be flush with the upper surface of the raft slab 1, it is easy to place the adjusting base 6 on the upper part of the raft slab 1 after the concrete of the raft slab 1 is poured, and the upper surface of the raft slab 1 is kept flat. By setting the first channel steel 3 and the second channel steel 4 in the raft slab 1, the stability of the rebar platform 9 is enhanced, and the load-bearing capacity of the raft slab 1 is improved. This prevents the cable tower 8 from displacing and tortuous deformation, thereby preventing the prestressed tendons 15 from affecting the rebar tying of the cable tower 8 and the outer wall 21 when the tendons are being cast, thus ensuring the stability of the building construction.

[0045] In this embodiment, the wall connection 13 includes an anchor plate 33 that is tightly attached to the foundation pit wall 11 and a hinged cylinder 36 that is disposed on the anchor plate 33 and used to connect the horizontal steel pipe 37. The hinged cylinder 36 is installed on one side of the anchor plate 33 through a hinge support 35. The anchor plate 33 is provided with expansion bolts 34 that are anchored into the foundation pit wall 11.

[0046] During actual construction, the wall ties 13 are arranged in a quincunx pattern on the foundation pit wall 11.

[0047] This invention addresses the challenges of compressed net space in foundation pits, especially in deep foundation pit projects, where complex geological conditions, high groundwater levels, high bearing capacity requirements, and complex surrounding building environments are present. By erecting the cable-stayed tower 8 before pouring the raft foundation 1, the bottom of the cable-stayed tower 8 can be integrated with the steel reinforcement of the raft foundation 1, ensuring the stability of the cable-stayed tower 8. Furthermore, by erecting the prestressing tendon platform 9 in the limited space of the deep foundation pit, the prestressing tendons 15 can be pre-embedded in one go. This allows for interleaved operations without affecting the process, ensuring the placement of the prestressing tendons 15 in the outer wall 21, and reducing the difficulty of construction.

[0048] Step 2: Embed prestressing tendons:

[0049] Step 201, Anchoring the fixed end of the prestressed tendon: Seal the fixed end of the prestressed tendon 15 into the extrusion anchor 16, and then connect the lower end of the longitudinal through bar 19 in the outer wall 21 and the extrusion anchor 16 to the lower reinforcement bar 14 of the raft slab.

[0050] In actual construction, tie wire is used to connect the lower end of the longitudinal through bar 19 and the extrusion anchor 16 to the lower reinforcement bar 14 of the raft slab.

[0051] Step 202: Pouring raft slab concrete: A waterstop steel plate 18 is installed between the bottom of the two side formworks of the outer wall 21. Then, concrete is poured within the design range of the raft slab 1 to the bottom of the adjusting base 6 to form the raft slab 1. The concrete inside the outer wall 21 is poured to the middle of the waterstop steel plate 18 to form the foundation guide wall 17.

[0052] During actual construction, the height of the foundation guide wall 17 is 300mm higher than the top of the raft slab 1.

[0053] Step 203: Lay prestressed tendons and tie external wall reinforcement: Tie multiple horizontal through bars 20 and multiple tie bars evenly between the two rows of longitudinal through bars 19 along the height direction of the longitudinal through bars 19. Then, set multiple positioning brackets at intervals on the multiple horizontal through bars 20. Pass the upper end of the prestressed tendon 15 through the positioning bracket and extend it upward from the side formwork of the external wall 21 to the bar-laying platform 9. Then, tie the prestressed tendon 15 to the longitudinal through bars 19 and the horizontal through bars 20 from bottom to top.

[0054] In actual construction, in order to facilitate the laying of prestressed tendons 15 and avoid scratching the outer sheath of prestressed tendons 15, the tie bars in the outer wall 21 need to be tied after the prestressed tendons 15 are laid. This is to ensure that the position of the prestressed tendons 15 remains straight. The laying of prestressed tendons 15 is carried out in sequence with the construction progress of the main building, which shortens the construction period.

[0055] In this embodiment, the positioning bracket includes a first limiting plate 31 arranged parallel to the horizontal through rib 20 and multiple sets of limiting units disposed between the horizontal through rib 20 and the first limiting plate 31. Each set of limiting units includes two parallel second limiting plates 32. One end of the second limiting plate 32 is connected to the first limiting plate 31, and a prestressed rib 15 is between the two second limiting plates 32.

[0056] During actual construction, a positioning bracket is placed every three horizontal through bars 20. The number of limiting units is the same as the number of a row of prestressed tendons 15 and they correspond one-to-one. By setting up positioning brackets, it is easy to ensure the straightness of the prestressed tendons 15.

[0057] In this embodiment, the length of the prestressing tendon 15 satisfy ;in, The design length of the prestressed tendon 15 inside the exterior wall 21. The operating length of prestressing tendon 15. The anchorage length of the prestressed tendon 15 extending into the raft slab 1.

[0058] In this embodiment, in step 202, as the laying height of the prestressing tendon 15 increases, the height of the tendon-laying platform 9 is moved accordingly. When the laying height of the prestressing tendon 15 is higher than the height of the lowest structural slab 22, an inter-floor support frame 23 is installed between two adjacent structural slabs 22. The inter-floor support frame 23 is fixedly connected to the cable tower 8, and a screw 24 passing through the structural slab 22 is installed on the inter-floor support frame 23. Nuts that abut against the upper and lower surfaces of the structural slab 22 are respectively installed on the screw 24.

[0059] In actual construction, the inter-floor support frame 23 is a double-row ground-supported scaffold.

[0060] Step 204, Pre-embed the tensioning end of the prestressing tendon: After the prestressing tendon 15 is laid to the designed height of the outer wall 21, tie the hidden beam steel bar 25 on the upper part of the outer wall 21, and install the spiral bar 26 sleeved on the prestressing tendon 15 on the hidden beam steel bar 25. Then, pass the extruded board 27 located on the upper part of the spiral bar 26 through the tensioning end of the prestressing tendon 15.

[0061] The tensioning end of the prestressing tendon 15 extends upward to the outside of the extruded polystyrene board 27, the lower end of the extruded polystyrene board 27 is located inside the template of the outer wall 21, and the upper end of the extruded polystyrene board 27 is located outside the template of the outer wall 21.

[0062] In actual construction, the portion of the prestressing tendon 15 extending beyond the extruded polystyrene plate 27 at its tensioning end is the operational length of the prestressing tendon 15. The lower end of the extruded polystyrene board 27 is at least 150mm away from the outer wall 21, so that a groove can be left after the outer wall 21 is poured as a tensioning pit for the prestressing tendon 15, thereby allowing the single-hole anchor 29 of the prestressing tendon 15 to be located in the tensioning pit.

[0063] Step 3: Pour concrete between the formwork of the outer wall 21 to the designed height of the outer wall 21 to form the outer wall 21. During actual construction, when vibrating the concrete of the outer wall 21 with a vibrator, the vibrator should not be directly in front of the prestressing tendon 15 to avoid displacement of the prestressing tendon 15.

[0064] Step 4: Tensioning the prestressing tendons: After the concrete strength of the outer wall 21 reaches 90%, install the bearing pad 28 and single-hole anchor 29 at the tensioning end of the prestressing tendon 15, tension the prestressing tendon 15 and seal the anchor. Then, pour expansion concrete 30 on the top of the outer wall 21 so that the single-hole anchor 29 of the prestressing tendon 15 is connected to the outer wall 21 as one unit, and the top of the outer wall 21 is flat.

[0065] During actual tensioning, a 60t front-clamping jack and a high-pressure oil pump are used for driving. The jack needs to be calibrated before tensioning. During tensioning, the principle of dual control of stress and theoretical elongation is adopted. The length of the tensioning end of the prestressing tendon 15 is measured before and after tensioning, and the elongation value is calculated. The deviation of the elongation value is controlled within ±6%. After tensioning, the exposed tensioning end is mechanically cut with steel strand, and the single-hole anchor 29 is sealed after being coated with anti-corrosion paint. The surface of the prestressing tendon 15 is ensured to be flat.

[0066] This invention employs a wedge-type single-hole anchor 29, which utilizes the wedge-tightening principle of the conical hole to anchor the steel strands. Specifically, the wedge-shaped wedges anchor the prestressing tendons 15 into the conical holes of the anchor plate. After the steel strand bundle is tensioned to the design stress value using a jack, the jack is slowly released. The wedges of the single-hole anchor 29 are then pulled into the conical holes of the anchor plate by the uniformly retracting prestressing tendons 15, forming an anchoring unit. The stress of the steel strand bundle is transmitted to the outer wall 21 through the anchor plate and anchor pad, forming permanent prestress.

[0067] This invention achieves the construction of vertical prestressed tendons 15 in the outer wall 21 before the construction of the basement outer wall 21, making the prestressed tendons 15 an integral part of the outer wall 21. This improves the performance of the outer wall 21, extends the building's lifespan, reduces temperature deformation and cracking of the outer wall 21, and improves the building's seismic performance. At the same time, the use of prestressed tendons 15 reduces the cross-sectional dimensions of the outer wall 21, reduces the amount of steel reinforcement, and lowers construction costs.

[0068] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for constructing basement exterior walls with one-time pre-embedded vertical prestressing, characterized in that, The method includes the following steps: Step 1: Construct the lifting platform: Step 101: Erecting the cable tower: Lay the first channel steel (3) under the upper reinforcing bar (2) of the raft foundation, lay the second channel steel (4) above the upper reinforcing bar (2) of the raft foundation, fix the vertical trestles (5) under the second channel steel (4), the first channel steel (3) and the second channel steel (4) are arranged in a grid pattern, install the adjusting base support (6) at multiple intersections of the first channel steel (3) and the second channel steel (4), fix the vertical support pipe (7) on the adjusting base support (6), install the cable tower (8) on the vertical support pipe (7), and then lay steel plates on the cable tower (8) to form a slack bar platform (9); Step 102, Tie the reinforcing bar platform: Install wall ties (13) on the pit wall (11), and then fix horizontal steel pipes (37) on the wall ties (13). The horizontal steel pipes (37) are connected to the vertical steel pipes of the cable tower (8) through fasteners (38). Step 2: Embed prestressing tendons: Step 201, Anchoring the fixed end of the prestressed tendon: Seal the fixed end of the prestressed tendon (15) into the extrusion anchor (16), and then connect the lower end of the longitudinal through bar (19) in the outer wall (21) and the extrusion anchor (16) to the lower reinforcement (14) of the raft slab. Step 202: Pouring raft concrete: Set a waterstop steel plate (18) between the bottom of the two side formworks of the outer wall (21), and then pour concrete into the raft (1) within the design range to the bottom of the adjustment base (6) to form the raft (1). The concrete inside the outer wall (21) is poured to the middle of the waterstop steel plate (18) to form the foundation guide wall (17). Step 203: Lay prestressed tendons and tie the outer wall reinforcement at the same time: Tie multiple horizontal through bars (20) and multiple tie bars evenly between the two rows of the longitudinal through bars (19) along the height direction of the longitudinal through bars (19), and then set multiple positioning brackets at intervals on the multiple horizontal through bars (20). Pass the upper end of the prestressed tendon (15) through the positioning bracket and extend it upward to the side template of the outer wall (21) onto the bar-laying platform (9). Then tie the prestressed tendon (15) to the longitudinal through bars (19) and the horizontal through bars (20) from bottom to top. Step 204: Embed the tensioning end of the prestressing tendon: After the prestressing tendon (15) is laid to the designed height of the outer wall (21), the hidden beam steel bar (25) is tied to the upper part of the outer wall (21), and the spiral bar (26) sleeved on the prestressing tendon (15) is installed on the hidden beam steel bar (25). Then, the extruded board (27) located on the upper part of the spiral bar (26) is inserted through the tensioning end of the prestressing tendon (15). Among them, the tensioning end of the prestressing tendon (15) extends upward to the outside of the extruded polystyrene board (27), the lower end of the extruded polystyrene board (27) is located inside the template of the outer wall (21), and the upper end of the extruded polystyrene board (27) is located outside the template of the outer wall (21). Step 3: Pour concrete between the formwork of the basement exterior wall (21) to the designed height of the exterior wall (21) to form the exterior wall (21). Step 4: Tensioning the prestressed tendons: After the concrete strength of the outer wall (21) reaches 90%, install the bearing pad (28) and single-hole anchor (29) at the tensioning end of the prestressed tendon (15), tension the prestressed tendon (15) and seal the anchor. Then pour expansion concrete (30) on the top of the outer wall (21) so that the single-hole anchor (29) of the prestressed tendon (15) is connected to the outer wall (21) as one unit, and the top of the outer wall (21) is flat.

2. The construction method for a basement exterior wall with one-time pre-embedded vertical prestressing as described in claim 1, characterized in that: In step 101, the upper surface of the second channel steel (4) is flush with the upper surface of the raft plate (1).

3. A method for constructing a basement exterior wall with one-time pre-embedded vertical prestressing as described in claim 1, characterized in that: The wall tie (13) includes an anchor plate (33) that is tightly attached to the pit wall (11) and a hinged tube (36) that is set on the anchor plate (33) and used to connect the horizontal steel pipe (37). The hinged tube (36) is installed on one side of the anchor plate (33) through a hinge support (35). The anchor plate (33) is provided with expansion bolts (34) that are anchored into the pit wall (11).

4. A method for constructing a basement exterior wall with one-time pre-embedded vertical prestressing as described in claim 1, characterized in that: The positioning bracket includes a first limiting plate (31) arranged parallel to the horizontal through bar (20) and multiple sets of limiting units arranged between the horizontal through bar (20) and the first limiting plate (31). Each set of limiting units includes two parallel second limiting plates (32), one end of the second limiting plate (32) is connected to the first limiting plate (31), and there is a prestressed tendon (15) between the two second limiting plates (32).

5. A method for constructing a basement exterior wall with one-time pre-embedded vertical prestressing as described in claim 1, characterized in that: The length of the prestressing tendon (15) satisfy ;in, The design length of the prestressed tendons (15) inside the exterior wall (21) is given. The operating length of the prestressing tendon (15) is... The anchorage length of the prestressed tendon (15) extending into the raft slab (1).

6. A method for constructing a basement exterior wall with one-time pre-embedded vertical prestressing as described in claim 1, characterized in that: In step 202, as the laying height of the prestressing tendon (15) increases, the height of the tendon-laying platform (9) is moved accordingly. When the laying height of the prestressing tendon (15) is higher than the height of the lowest structural slab (22), an inter-floor support frame (23) is installed between two adjacent structural slabs (22). The inter-floor support frame (23) is fixedly connected to the cable tower (8), and a screw rod (24) passing through the structural slab (22) is installed on the inter-floor support frame (23). Nuts that abut against the upper and lower surfaces of the structural slab (22) are respectively installed on the screw rod (24).

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