Construction method of vertical dry connection structure for precast shear wall

Abstract

The present invention discloses a construction method for a vertical dry connection structure of precast shear wall. In the upper and lower precast shear wall components of the dry connection structure, vertical stressed connection steel bars and vertical stressed connection steel pipes are alternately arranged. The vertical stressed connection steel bars in the precast shear wall components are inserted into the vertical stressed connection steel pipes in the corresponding precast shear wall components vertically. The vertical stressed connection steel bars are provided with external threads, the vertical stressed connection steel pipes are provided with internal threads, and the internal and external double-thread nuts have internal and external threads. The internal and external double-thread nuts are sleeved outside the vertical stressed connection steel bars and are sleeved in the inner cavity of the vertical stressed connection steel pipes. The vertical stressed connection steel bars, the internal and external double-thread nuts, and the vertical stressed connection steel pipes are connected by threads. It improves the construction efficiency, realizes reliable connection, facilitates the installation of wall panels, speeds up the structural construction speed, and improves the prefabrication level of the building structure.

Description

Technical Field

[0001] The invention belongs to the technical field of connection structures of prefabricated building structures, and particularly relates to a construction method for a vertical dry connection structure of a precast shear wall. Background Art

[0002] In recent years, precast concrete shear wall structures have been widely used in the field of building construction. Since they effectively improve the construction quality and efficiency, save materials, energy, reduce emissions, are environmentally friendly, save labor and improve working conditions, shorten the construction period, and are convenient for winter construction, etc., they are widely used in the industrialization of buildings in China.

[0003] In precast concrete shear wall components, the vertical connection of precast shear walls is one of the key technologies. The connection nodes of precast concrete components are the weak links of precast shear wall structures. The vertical steel bars in precast concrete components are the key to the connection. A mature and reliable node connection technology is the key to ensuring the integrity and safety of precast concrete structures. A superior precast concrete component steel bar connection technology should simultaneously have the characteristics of safe and reliable connection, easy prefabrication, production, transportation and construction, and low cost, which is also the development direction of efficient connection of precast concrete component steel bars.

[0004] At present in China, the commonly used vertical connection methods for precast shear walls are sleeve grouting connection and confined slurry anchor lap connection, etc. Sleeve grouting connection has the advantages of safety, reliability and wide application range. However, sleeve grouting connection has a high cost, and the vertical steel bars at the non-grouting end of the commonly used semi-grouting sleeves need to be processed, which not only increases the production cost, but also makes it difficult to guarantee the connection performance of the processed ends. Compared with sleeve grouting connection, confined slurry anchor connection has the advantage of low cost, but there are problems such as complex prefabrication processes, difficult positioning of spiral stirrups, low production efficiency, and great difficulties in transportation and installation. In addition, both sleeve grouting connection and confined slurry anchor connection have grouting holes and exhaust holes. The existence of grouting holes and exhaust holes will, on the one hand, increase the production processes of precast concrete components, and on the other hand, pressure grouting cannot ensure the denseness of the grouting material. Moreover, the connection joints of the longitudinal stressed steel bars of the shear wall in the above two methods are in the same plane, which poses certain safety hazards. And the grouting holes and the connecting hoses of the slurry outlet holes of the grouting sleeves extend out of the wall for grouting. When reserved operation holes for buried pipelines and construction holes for reserved scaffolding are reserved in the project, interference problems are very likely to occur. Moreover, at the position of the concealed column, the connection sleeves are arranged densely, resulting in too many connecting hoses for grouting holes and slurry outlet holes, reducing the bearing capacity strength of the concrete wall at this position and posing certain safety hazards. Summary of the Invention

[0005] The present invention provides a construction method for a vertical dry connection structure of precast shear walls, aiming to solve the deficiencies of sleeve grouting connection and grout anchor lap connection in the vertical connection of precast concrete shear walls in the prior art. Combining the mechanical connection principle, a vertical dry connection structure of precast shear walls with excellent comprehensive performance is proposed based on the safety of precast concrete shear wall structures and the simplicity of actual construction. As a more convenient, fast and reliable vertical connection method for shear walls, it realizes reliable connection, facilitates the installation of wall panels, speeds up the construction speed of the structure, and improves the prefabrication level of building structures.

[0006] The vertical dry connection structure of the precast shear wall of the present invention, including its precast shear wall components, comprises an upper precast shear wall component (1) and a lower precast shear wall component (2). The upper precast shear wall component (1) is hoisted to a predetermined position above the lower precast shear wall component (2) and aligned with the lower precast shear wall component (2); vertically stressed connecting steel bars (3) and vertically stressed connecting steel pipes (4) are alternately arranged in the upper precast shear wall component (1) and the lower precast shear wall component (2) respectively; the vertically stressed connecting steel bars (3) in the precast shear wall component are inserted into the vertically corresponding vertically stressed connecting steel pipes (4) in the precast shear wall component; the vertically stressed connecting steel bars (3) are provided with external threads, the vertically stressed connecting steel pipes (4) are provided with internal threads, and the internal and external double-thread nuts (9) are provided with internal threads and external threads; the internal and external double-thread nuts (9) are sleeved outside the vertically stressed connecting steel bars (3), and the internal and external double-thread nuts (9) are sleeved in the inner cavity (8) of the vertically stressed connecting steel pipes (4), and the vertically stressed connecting steel bars (3), the internal and external double-thread nuts (9) and the vertically stressed connecting steel pipes (4) are connected by threads.

[0007] In the above solution, preferably, the internal and external double-thread nuts (9) are composed of two semi-cylindrical ring-shaped semi-double-thread nuts.

[0008] It is also preferable that grooves (10) are respectively provided on the side walls on both sides of the open ends of the two semi-cylindrical ring-shaped semi-double-thread nuts, and the grooves (10) of the two semi-double-thread nuts are aligned and connected by connectors (11) provided in the grooves (10).

[0009] It is also preferable that the grooves (10) are arc-shaped grooves and the connectors (11) are arc-shaped plates.

[0010] It is also preferable that the grooves (10) open on the top surface of the semi-double-thread nuts.

[0011] The construction tool for the vertical dry connection structure of the precast shear wall of the present invention includes an auxiliary fastening tool (12), and the auxiliary fastening tool (12) includes two tool plates (120). During use, the two tool plates (120) respectively extend into the grooves (10) where the two semi double-threaded nuts are aligned.

[0012] The construction method for the vertical dry connection structure of the precast shear wall of the present invention includes the following steps:

[0013] The first step, positioning of the connecting members: Alternately arrange the vertical stressed connecting steel bars (3) and the vertical stressed connecting steel pipes (4) in the upper precast shear wall member (1) and the lower precast shear wall member (2).

[0014] The second step, pouring and precasting of the precast shear wall member.

[0015] The third step, curing and demolding inspection of the precast shear wall member.

[0016] The fourth step, hoisting construction and installation of the precast shear wall.

[0017] It includes: Hoisting the upper precast shear wall member (1) to a predetermined position above the lower precast shear wall member (2) and aligning it with the lower precast shear wall member (2); Inserting the vertical stressed connecting steel bar (3) in the upper precast shear wall member (1) into the vertical stressed connecting steel pipe (4) in the lower precast shear wall member (2) below it; Then inserting the internal and external double-threaded nut (9) into the inner cavity (8) of the vertical stressed connecting steel pipe (4) and sleeving and connecting the internal and external double-threaded nut (9) outside the vertical stressed connecting steel bar (3); Finally, sealing and compartment grouting the construction joint between the upper precast shear wall member (1) and the lower precast shear wall member (2) to achieve the mechanical dry connection of the precast shear wall.

[0018] Preferably in the above solution, when inserting the internal and external double-threaded nut (9) into the inner cavity (8) of the vertical stressed connecting steel pipe (4) and sleeving and connecting the internal and external double-threaded nut (9) outside the vertical stressed connecting steel bar (3), it is carried out through the auxiliary fastening tool (12); The auxiliary fastening tool (12) includes two tool plates (120). Insert the two tool plates (120) into the grooves (10) where the two semi double-threaded nuts are aligned respectively, and drive the internal and external double-threaded nut (9) to rotate by rotating the auxiliary fastening tool (12), so that the internal and external double-threaded nut (9) rotates into the vertical stressed connecting steel pipe (4).

[0019] It can also be preferably set that the number of the internal and external double-threaded nuts (9) is at least two, the end faces of adjacent internal and external double-threaded nuts (9) are flush, and the total length of all the internal and external double-threaded nuts (9) ≥ the length of the internal thread of the vertical stressed connecting steel pipe (4).

[0020] Preferably, before the curing and demolding inspection of the precast shear wall component in the third step, the internal thread on the inner wall of the vertical force-bearing connecting steel pipe (4) should be subjected to a pull-out test according to the connecting joint. The principle of the pull-out test is to randomly select at least two groups from the vertical force-bearing connecting steel bars (3), vertical force-bearing connecting steel pipes (4), and internal and external double-thread nuts (9) in the same inspection lot when they enter the site; then bind the steel bar skeletons of the local shear wall; bind the vertical force-bearing connecting steel pipe (4) to the steel bar skeleton, and pour concrete to form a reinforced concrete specimen. After curing until the concrete reaches final setting, insert the vertical force-bearing connecting steel bar (3) into the corresponding vertical force-bearing connecting steel pipe (4), and use the internal and external double-thread nuts (9) to complete the fastening connection; set ribbed structures on the outer wall of the vertical force-bearing connecting steel pipe (4); then conduct a pull-out test. When the vertical force-bearing connecting steel bar (3) is first pulled off, the pull-out requirement is met. When the vertical force-bearing connecting steel pipe (4) is first pulled out, increase the density and depth of the ribbed structure on the outer wall of the vertical force-bearing connecting steel pipe (4). When the vertical force-bearing connecting steel bar (3) is pulled out, increase the insertion depth of the vertical force-bearing connecting steel bar (3) until the pull-out requirement is met.

[0021] The beneficial effects of the present invention are:

[0022] The construction method of the precast shear wall vertical dry connection structure of the present invention can overcome the deficiencies and defects of the existing vertical connection of precast concrete shear walls. According to the mechanical connection principle and the method of embedding vertical force-bearing connecting steel pipes with internal threads at the end, an improved precast shear wall vertical dry connection structure and its construction method are proposed. It pre-embeds vertical force-bearing connecting steel pipes with internal threads at the ends replacing vertical force-bearing steel bars at intervals during the casting of upper and lower precast shear walls, and the upper and lower precast shear wall components can be spaced out with vertical steel bars with external threads at the ends. The vertical steel bars are all inserted into the corresponding vertical force-bearing connecting steel pipes with internal threads at the ends, and the vertical force-bearing connecting steel pipes and vertical steel bars are mechanically connected through internal and external double-thread nuts, greatly improving the construction efficiency; as a more convenient, fast and reliable vertical connection method for shear walls, it realizes reliable connection, facilitates the installation of wall panels, speeds up the construction speed of the structure, and improves the prefabrication level of the building structure. Description of the Drawings

[0023] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0024] Figure 1 It is a schematic diagram of the split structure of the vertical connection of the upper and lower shear wall components related to the present invention.

[0025] Figure 2 Related to the present inventionFigure 2 Schematic diagram of the C-C cross-sectional structure

[0026] Figure 3 This invention relates to Figure 2 Schematic diagram of the D-D cross-sectional structure

[0027] Figure 4 This invention relates to Figure 2 Schematic diagram of the A-A cross-sectional structure

[0028] Figure 5 This invention relates to Figure 2 Schematic diagram of the B-B cross-sectional structure

[0029] Figure 6 Schematic diagram of the structural combination for vertical connection of upper and lower shear wall members

[0030] Figure 7 This invention Figure 7 Schematic diagram of the enlarged I local structure

[0031] Figure 8 This invention Figure 7 and Figure 8 Schematic diagram of the split structure of the internal and external double-threaded nut monomer

[0032] Figure 9 This invention Figure 7 and Figure 8 Schematic diagram of the combined structure of the internal and external double-threaded nut monomer

[0033] Figure 10 This invention Figure 7 and Figure 8 Schematic diagram of the split structure of the internal and external double-threaded nut double body

[0034] Figure 11 This invention Figure 7 and Figure 8 Schematic diagram of the combined structure of the internal and external double-threaded nut double body

[0035] Figure 12 This invention Figure 7 and Figure 8 Schematic diagram of the vertical force-bearing connecting steel bars

[0036] Figure 13 This invention Figure 7 and Figure 8 Schematic diagram of the vertical force-bearing connecting steel pipes

[0037] Figure 14 This invention Figure 7 and Figure 8Schematic diagram of the combined structure of vertical force-bearing connecting steel bars, vertical force-bearing connecting steel pipes and internal and external double-thread nuts in it.

[0038] Figure 15 Schematic diagram of the disassembled structure of the auxiliary fastening tool of the present invention.

[0039] Figure 16 Schematic diagram of the combined structure of the auxiliary fastening tool of the present invention.

[0040] Figure 17 Schematic block diagram of the construction method flow of the present invention.

[0041] In the figure, 1 is the upper precast shear wall member, 2 is the lower precast shear wall member, 3 is the vertical force-bearing connecting steel bar, 4 is the vertical force-bearing connecting steel pipe, 5 is the major diameter of the internal thread of the vertical force-bearing connecting steel pipe, 6 is the minor diameter of the internal thread of the vertical force-bearing connecting steel pipe, 7 is the cushion block, 8 is the inner cavity, 9 is the internal and external double-thread nut, 10 is the groove, 11 is the connecting piece, 12 is the auxiliary fastening tool, and 120 is the tool plate. Specific embodiments

[0042] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0043] The following will, in conjunction with the drawings, detail the technical solutions provided by each embodiment of the present invention.

[0044] Embodiment 1

[0045] As Figures 1 to 9 As Figures 12 to 16, A precast shear wall vertical dry connection structure, including its precast shear wall components including an upper precast shear wall component 1 and a lower precast shear wall component 2. The upper precast shear wall component 1 is hoisted to a predetermined position above the lower precast shear wall component 2 and aligned with the lower precast shear wall component 2; vertically stressed connecting steel bars 3 and vertically stressed connecting steel pipes 4 are alternately arranged in the upper precast shear wall component 1 and the lower precast shear wall component 2 respectively; the vertically stressed connecting steel bars 3 in the precast shear wall component are inserted into the vertically corresponding vertically stressed connecting steel pipes 4 in the precast shear wall component; the vertically stressed connecting steel bars 3 are provided with external threads, the vertically stressed connecting steel pipes 4 are provided with internal threads, and the internal and external double-thread nuts 9 are provided with internal threads and external threads; the internal and external double-thread nuts 9 are sleeved outside the vertically stressed connecting steel bars 3, and the internal and external double-thread nuts 9 are sleeved in the inner cavity 8 of the vertically stressed connecting steel pipes 4, and the vertically stressed connecting steel bars 3, the internal and external double-thread nuts 9 and the vertically stressed connecting steel pipes 4 are connected by threads.

[0046] Example 2

[0047] Such as Figures 8 to 11 , For the precast shear wall vertical dry connection structure of Example 1, further, the internal and external double-thread nuts 9 are composed of two semi-cylindrical ring-shaped semi-double-thread nuts.

[0048] Such as Figures 8 to 11 , Further, grooves 10 are respectively arranged on the side walls on both sides of the open ends of the two semi-cylindrical ring-shaped semi-double-thread nuts, and the grooves 10 of the two semi-double-thread nuts are aligned and connected by a connecting piece 11 arranged in the grooves 10.

[0049] Such as Figures 8 to 11 , Further, the groove 10 is an arc-shaped groove, and the connecting piece 11 is an arc-shaped plate.

[0050] Such as Figures 8 to 11 , Further, the groove 10 opens on the top surface of the semi-double-thread nut.

[0051] Example 3

[0052] Such as Figure 15 And Figure 16 , The construction tool for any of the above precast shear wall vertical dry connection structures includes an auxiliary fastening tool 12, and the auxiliary fastening tool 12 includes two tool plates 120. During use, the two tool plates 120 respectively extend into the grooves 10 where the two semi-double-thread nuts are aligned.

[0053] Example 4

[0054] Such as Figure 17 As shown, the construction method of the precast shear wall vertical dry connection structure of Example 1 or Example 2 includes the following steps:

[0055] First step, positioning of connecting components: Alternately arrange the vertical load-bearing connecting steel bars 3 and the vertical load-bearing connecting steel pipes 4 in the upper precast shear wall component 1 and the lower precast shear wall component 2.

[0056] Second step, casting and precasting of precast shear wall components.

[0057] Third step, curing and demoulding inspection of precast shear wall components.

[0058] Fourth step, hoisting construction and installation of precast shear walls.

[0059] Including: Hoist the upper precast shear wall component 1 to a predetermined position above the lower precast shear wall component 2 and align it with the lower precast shear wall component 2; Insert the vertical load-bearing connecting steel bar 3 in the upper precast shear wall component 1 into the vertical load-bearing connecting steel pipe 4 in the lower precast shear wall component 2 below it; Then insert the internal and external double-threaded nut 9 into the inner cavity 8 of the vertical load-bearing connecting steel pipe 4 and sleevedly connect the internal and external double-threaded nut 9 outside the vertical load-bearing connecting steel bar 3; Finally, seal and grout the construction joint between the upper precast shear wall component 1 and the lower precast shear wall component 2 to achieve mechanical dry connection of the precast shear wall.

[0060] Example 5

[0061] For the construction method of the vertical dry connection structure of the precast shear wall in Example 3, further, when inserting the internal and external double-threaded nut 9 into the inner cavity 8 of the vertical load-bearing connecting steel pipe 4 and sleevedly connecting the internal and external double-threaded nut 9 outside the vertical load-bearing connecting steel bar 3, it is carried out through the auxiliary fastening tool 12; The auxiliary fastening tool 12 includes two tool plates 120. Insert the two tool plates 120 into the grooves 10 where the two half double-threaded nuts are aligned respectively, and drive the internal and external double-threaded nut 9 to rotate by rotating the auxiliary fastening tool 12, so that the internal and external double-threaded nut 9 rotates into the vertical load-bearing connecting steel pipe 4.

[0062] Further, the number of the internal and external double-threaded nuts 9 is set to at least two, the end faces of adjacent internal and external double-threaded nuts 9 are flush, and the total length of all the internal and external double-threaded nuts 9 ≥ the length of the internal thread of the vertical load-bearing connecting steel pipe 4.

[0063] Furthermore, in the third step, before the curing and demoulding inspection of the precast shear wall components, the internal threads on the inner wall of the vertical force-bearing connecting steel pipe 4 should be subjected to a tensile test according to the connecting joint. The principle of the tensile test is to randomly select at least two groups from the vertical force-bearing connecting steel bars 3, vertical force-bearing connecting steel pipes 4 and internal and external double-thread nuts 9 in the same batch of incoming inspection; then bind the steel bar skeletons of the local shear wall; bind the vertical force-bearing connecting steel pipe 4 to the steel bar skeleton, and pour concrete to form a reinforced concrete test piece. After curing until the concrete reaches final setting, insert the vertical force-bearing connecting steel bar 3 into the corresponding vertical force-bearing connecting steel pipe 4, and use the internal and external double-thread nuts 9 to complete the fastening connection; set a ribbed structure on the outer wall of the vertical force-bearing connecting steel pipe 4; then conduct a pull-out test. When the vertical force-bearing connecting steel bar 3 is first broken, the pull-out requirement is met. When the vertical force-bearing connecting steel pipe 4 is first pulled out, increase the density and depth of the ribbed structure on the outer wall of the vertical force-bearing connecting steel pipe 4. When the vertical force-bearing connecting steel bar 3 is pulled out, increase the insertion depth of the vertical force-bearing connecting steel bar 3 until the pull-out requirement is met.

[0064] Example 6

[0065] The above-mentioned precast shear wall vertical dry connection structure, construction tools and construction methods may include the following specific structures and step contents in specific construction:

[0066] In the first step, the split design of the precast shear wall components. Considering the building structure construction drawings and structural loads comprehensively, the cast-in-place reinforced concrete shear wall is split and deepened according to the "Design Code for Assembled Concrete Structures", and the deepened design drawing of the assembled structure is drawn to determine the processing details of each precast shear wall component, and determine the positions, diameters, strength grades, etc. of the vertical force-bearing connecting steel bars 3 with external threads at the ends and the vertical force-bearing connecting steel pipes 4 with internal threads at the ends of the precast shear wall components.

[0067] In the second step, the determination of the relevant properties of the vertical force-bearing internal thread connecting steel pipe, including:

[0068] (1) Positioning of the connecting components:

[0069] According to the positions of the vertical connection nodes of each precast shear wall determined in the first step, the diameters, spacings, major and minor diameters of the external threads of the vertical force-bearing connecting steel bars 3 with external threads at the ends, the vertical force-bearing connecting steel pipes 4 with internal threads at the ends are positioned based on the principle that the vertical force-bearing connecting steel bars 3 with external threads at the ends can be accurately inserted into the corresponding vertical force-bearing connecting steel pipes 4. The vertical force-bearing connecting steel pipes 4 with internal threads at the ends are alternately arranged with the vertical force-bearing connecting steel bars 3 in the precast shear walls of the same layer.

[0070] (2) Design of the vertical force-bearing connecting steel pipe:

[0071] The outer wall of the vertical force-bearing connecting steel pipe 4 can be provided with ribbed structures, and its end contains internal threads. The length of the internal threads is equal to the anchorage length of the vertical force-bearing connecting steel bar 3, and the anchorage length of the vertical force-bearing connecting steel bar 3 is the length l of its external threads. l , the length l of its external threads l can be calculated and determined according to the length calculated in the "Code for Design of Concrete Structures" (GB 50010-2010) by the following formula:

[0072]

[0073] l a = ξ a l ab (2)

[0074] l l = βξ 1 l a (3)

[0075] In the formula: α is the shape coefficient of the anchorage steel bar, and the value can be found in the "Code for Design of Concrete Structures" (GB 50010-2010); l ab is the basic anchorage length of the tension steel bar; f y is the design value of the tensile strength of the ordinary steel bar; f t is the design value of the axial tensile strength of the concrete; d is the diameter of the anchorage steel bar; l a is the anchorage length of the tension steel bar; ξ a is the anchorage length correction coefficient, and the value can be found in the "Code for Design of Concrete Structures" (GB 50010-2010); l l is the connection length of the longitudinal tension steel bar; β is the reliability index of the structural member, and the value can be found in the "Unified Standard for Reliability Design of Building Structures" (GB50068-2018); ξ 1 is the connection length correction coefficient of the longitudinal tension steel bar, and the value can be found in the "Code for Design of Concrete Structures" (GB 50010-2010).

[0076] According to the external thread length of the vertical force-bearing connecting steel bar 3 determined above, the length l of the extended steel bar of the vertical force-bearing connecting steel bar of the precast shear wall is determined by the following formula:

[0077] l = l l + l b + l c + l d (4)

[0078] In the formula: l b is the floor slab thickness; l c is the grouting thickness of the 10mm composite slab; l d is the grouting thickness of the upper and lower precast shear walls of 20mm.

[0079] (3) Determination of the material and dimensions of the vertical force-bearing connecting steel pipe:

[0080] According to the structural load, force-bearing form of the shear wall component and relevant codes, calculate the structural bearing capacity requirements. The selected vertical force-bearing connecting steel pipe 4 has a tensile strength not less than the structural calculated bearing capacity. The inner diameter D is equal to 2 times the diameter d of the connecting steel bar. The wall thickness is calculated and determined according to relevant codes to meet the bearing capacity check. The outer wall of the steel pipe has crescent-shaped ribs to improve the bond strength of the concrete. The connection joint design requires an anti-pullout test for the connection joint. The principle of the anti-pullout test is as follows: Randomly select three groups from the incoming vertical force-bearing connecting steel bars 3, vertical force-bearing connecting steel pipes 4 and internal and external double-thread nuts 9 in the same inspection lot. To simulate the real force, bind the steel bar skeletons of the local shear wall. Among them, the force-bearing steel pipes are bound to the steel bar skeletons, and concrete is poured to form reinforced concrete specimens. After curing until the concrete reaches final setting, insert the vertical force-bearing connecting steel bar 3 into the corresponding vertical force-bearing connecting steel pipe 4, and use the internal and external double-thread nuts 9 to complete the fastening connection. Then conduct a pull-out test. When the steel bar is first pulled off and meets the requirements, when the steel pipe is first pulled out, it is necessary to increase the rib density and depth of the outer wall of the steel pipe. When the steel bar is pulled out, it is necessary to increase the insertion depth of the connecting steel bar until the requirements are met. The connection schematic diagram of the vertical force-bearing connecting steel bar 3, vertical force-bearing connecting steel pipe 4 and internal and external double-thread nuts 9 can be seen in Figure 14 。

[0081] Thirdly, determine the relevant properties of the internal and external double-thread nuts. According to the analysis and research, it is determined that the internal and external double-thread nuts 9 are mainly under pressure. Therefore, ductile iron materials with better compressive performance are selected for production. Determine the external thread size properties of the internal and external double-thread nuts 9 according to the internal thread of the vertical force-bearing connecting steel pipe 4, and determine the internal thread size properties of the internal and external double-thread nuts 9 according to the external thread of the vertical force-bearing connecting steel bar 3, so that the three threads are matched and connected, as Figure 14 shown. The internal and external double-thread nuts 9 are overall hollow cylinders, with an inner diameter equal to d, an outer diameter equal to 1.5d, and a wall thickness equal to 0.5d. It consists of three parts, including a hollow semi-cylinder with a central angle of 180° with a through-arc groove 10 at both ends, and a hollow sector cylinder connector 11 with dimensions matching the through-arc groove 10. Its monomer is as Figure 8 and Figure 9 shown. Its connector 11 is used to connect two internal and external double-thread nuts 9. The length of the connector 11 is evenly distributed and penetrates through the through-arc grooves 10 of the two internal and external double-thread nuts 9, so that the two internal and external double-thread nuts 9 form a whole, see Figure 10 and Figure 11 。

[0082] Step 4: Determination of relevant properties of the auxiliary fastening tool. Since it is difficult to perform rotational fastening operations on the internal and external double-threaded nut 9, the auxiliary fastening tool 12 is used to assist in the rotational fastening of the internal and external double-threaded nut 9 for vertically stress-bearing connecting steel bar 3 and vertically stress-bearing connecting steel pipe 4. Since the auxiliary fastening tool 12 is mainly subjected to torque and shear forces, its material is preferably structural alloy steel with high shear strength and strong torsional resistance. The auxiliary fastening tool 12 is mainly formed by a circular hollow hexagonal prism at the end and can be divided into two halves. On each half, a tool plate 120 with the same size and shape as the connecting piece 11 of the hollow sector cylinder is connected. The tool plate 120 is a steel sheet, and its structure is as Figure 15 and Figure 16 .

[0083] Step 5: Casting and prefabrication of precast shear wall components. Determine the position, size, model, and other information of the vertically stress-bearing connecting steel bar 3 and the vertically stress-bearing connecting steel pipe 4 according to the processing details of the precast shear wall. Arrange the steel bar skeleton of the precast shear wall. Among them, the vertically stress-bearing connecting steel pipe 4 and the steel bar mesh can be tied and connected using horizontal stirrups and tie bars, so that the vertically stress-bearing connecting steel pipe 4 and the shear wall become an effective whole, and vertical lapped bars are made for the vertically stress-bearing connecting steel bar 3. The length of the lapped bars can be l l + 20 mm. The two ends of the vertically stress-bearing connecting steel pipe 4 can be blocked with rubber plugs, and then the mold for the precast concrete shear wall component is assembled using the flat mold method, and the concrete of the shear wall component is poured.

[0084] Step 6: Curing and demolding inspection of precast shear wall components. The steam curing method can be used to cure the poured shear wall components. After the concrete has initially set, the plugs at both ends of the vertically stress-bearing connecting steel pipe 4 are removed in a timely manner to avoid temperature stress damage to the connection quality of the steel pipe and the concrete caused by the air sealed inside the vertically stress-bearing connecting steel pipe 4 during the steam curing process, and anti-corrosion treatment is carried out on the lapped bars. After curing, the mold of the shear wall component is removed, and the surface, size, position of the vertically stress-bearing connecting steel bar 3 and the vertically stress-bearing connecting steel pipe 4 of the shear wall component are inspected, the vertically stress-bearing connecting steel bar 3 is straightened, protective facilities are installed, and then all the shear wall components are transported to the site in sequence according to the transportation plan.

[0085] Step 7: Hoisting and installation of precast shear walls. Before hoisting, straighten and remove rust from the vertical force-bearing connecting steel bars 3 again to ensure that the steel bars are accurately inserted into the corresponding vertical force-bearing connecting steel pipes 4. Place a cushion block 7 on the top of the lower-layer precast shear wall member 2. The thickness of the cushion block 7 can be 20 mm. According to the hoisting plan, hoist the upper-layer precast shear wall member 1 to align it with the predetermined position of the lower-layer precast shear wall member 2. Insert the vertical force-bearing connecting steel bars 3 and the corresponding vertical force-bearing connecting steel pipes 4 of the upper and lower precast shear walls one by one. Then, put the two half-structures of the internal and external double-threaded nut 9 over the vertical force-bearing connecting steel bar 3. Insert the hollow sector cylinder connector 11 of the auxiliary fastening tool 12 into the through-arc groove 10 of the internal and external double-threaded nut 9. Then, use a wrench to rotate the internal and external double-threaded nut 9 through the auxiliary fastening tool 12 into the vertical force-bearing connecting steel pipe 4 to effectively fasten and connect the vertical force-bearing connecting steel bar 3 and the vertical force-bearing connecting steel pipe 4. Stop rotating when the bottom surface of the first internal and external double-threaded nut 9 is flush with the bottom surface of the vertical force-bearing connecting steel pipe 4. Install the second internal and external double-threaded nut 9, ensuring that the through-arc grooves 10 of the two internal and external double-threaded nuts 9 are aligned. Insert the hollow sector cylinder connector 11 into the through-arc grooves 10 of the two internal and external double-threaded nuts 9. Then, insert the hollow sector cylinder connector 11 of the auxiliary fastening tool 12 in the same way, and push the hollow sector cylinder connector 11 into the middle of the through-arc grooves 10 of the two internal and external double-threaded nuts 9 to complete their connection. Then, use a wrench to rotate the internal and external double-threaded nut 9 through the auxiliary fastening tool 12 into the vertical force-bearing connecting steel pipe 4 and stop rotating when the bottom surface of the bottom of the second internal and external double-threaded nut 9 is flush with the bottom surface of the vertical force-bearing connecting steel pipe 4. Repeat the above steps until the total length of the internal and external double-threaded nuts 9 screwed into the vertical force-bearing connecting steel pipe 4 is not less than the internal thread length of the vertical force-bearing connecting steel pipe 4 to complete the connection. Repeat the above steps to complete the mechanical connection of other connection nodes in sequence. Finally, seal and grout the construction joint between the upper and lower precast shear walls. The width of the construction joint can be 20 mm. Complete the mechanical dry connection of the precast shear walls according to the above steps in sequence.

[0086] The above are only the embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A construction method for a vertical dry connection structure of precast shear walls. The vertical dry connection structure of precast shear walls includes precast shear wall components, which include an upper precast shear wall component (1) and a lower precast shear wall component (2). It is characterized in that the upper precast shear wall component (1) is hoisted to a predetermined position above the lower precast shear wall component (2) and aligned with the lower precast shear wall component (2); vertically stressed connecting steel bars (3) and vertically stressed connecting steel pipes (4) are alternately arranged in the upper precast shear wall component (1) and the lower precast shear wall component (2); the vertically stressed connecting steel bars (3) in the precast shear wall component are inserted into the vertically stressed connecting steel pipes (4) corresponding to them vertically in the precast shear wall component; the vertically stressed connecting steel bars (3) are provided with external threads, the vertically stressed connecting steel pipes (4) are provided with internal threads, and the internal and external double-thread nuts (9) are provided with internal threads and external threads; the internal and external double-thread nuts (9) are sleeved outside the vertically stressed connecting steel bars (3), and the internal and external double-thread nuts (9) are sleeved in the inner cavity (8) of the vertically stressed connecting steel pipes (4), and the vertically stressed connecting steel bars (3), the internal and external double-thread nuts (9) and the vertically stressed connecting steel pipes (4) are connected by threads; the internal and external double-thread nuts (9) are integrally a hollow cylinder, which consists of three parts, including a hollow semi-cylinder with a central angle of 180° with through-arc grooves (10) at both ends, and a hollow sector cylinder connector (11) with dimensions matching the through-arc grooves (10). The connector (11) is used to connect two internal and external double-thread nuts (9), and the length of the connector (11) is evenly distributed through the through-arc grooves (10) of the two internal and external double-thread nuts (9) to make the two internal and external double-thread nuts (9) form a whole; The construction method includes the following steps: The first step, positioning of connecting components: The vertically stressed connecting steel bars (3) and the vertically stressed connecting steel pipes (4) are alternately arranged in the upper precast shear wall component (1) and the lower precast shear wall component (2); The second step, casting and prefabrication of precast shear wall components; The third step, curing and demoulding inspection of precast shear wall components; The fourth step, hoisting construction and installation of precast shear walls; including: hoisting the upper precast shear wall component (1) to a predetermined position above the lower precast shear wall component (2) and aligning it with the lower precast shear wall component (2); inserting the vertically stressed connecting steel bars (3) in the upper precast shear wall component (1) into the vertically stressed connecting steel pipes (4) in the lower precast shear wall component (2) below it; Then, the internal and external double-threaded nut (9) is inserted into the inner cavity (8) of the vertical force-bearing connecting steel pipe (4) through the auxiliary fastening tool (12), and the internal and external double-threaded nut (9) is sleeved and connected outside the vertical force-bearing connecting steel bar (3); the auxiliary fastening tool (12) forms an end with a circular hollow hexagonal prism and is divided into two halves. Each half is connected with a tool plate (120) having the same size and shape as the connecting piece (11) of the hollow sector cylinder; the two tool plates (120) are respectively inserted into the grooves (10) aligned with the two half double-threaded nuts, and then the two half structures of the internal and external double-threaded nut (9) are sleeved outside the vertical force-bearing connecting steel bar (3). The hollow sector cylinder connecting piece (11) of the auxiliary fastening tool (12) is inserted into the through-arc groove (10) of the internal and external double-threaded nut (9), and then a wrench is used to rotate the internal and external double-threaded nut (9) through the auxiliary fastening tool (12) into the vertical force-bearing connecting steel pipe (4), so that the vertical force-bearing connecting steel bar (3) and the vertical force-bearing connecting steel pipe (4) are tightly connected; When the bottom surface of the first internal and external double-threaded nut (9) is flush with the bottom surface of the vertical force-bearing connecting steel pipe (4), stop rotating, install the second internal and external double-threaded nut (9), ensure that the through-arc grooves (10) of the two internal and external double-threaded nuts (9) are aligned, and insert the hollow sector cylinder connecting piece (11) into the through-arc grooves (10) of the two internal and external double-threaded nuts (9); then insert the hollow sector cylinder connecting piece (11) of the auxiliary fastening tool (12) in the same way, push the hollow sector cylinder connecting piece (11) into the middle of the through-arc grooves (10) of the two internal and external double-threaded nuts (9) to complete the connection between the two; then use a wrench to rotate the internal and external double-threaded nut (9) through the auxiliary fastening tool (12) into the vertical force-bearing connecting steel pipe (4) until the bottom surface of the bottom of the second internal and external double-threaded nut (9) is flush with the bottom surface of the vertical force-bearing connecting steel pipe (4), and then stop rotating; repeat the above steps until the total length of the internal and external double-threaded nuts (9) screwed into the vertical force-bearing connecting steel pipe (4) is not less than the internal thread length of the vertical force-bearing connecting steel pipe (4), and then stop to complete the connection; Finally, the construction joints of the upper precast shear wall component (1) and the lower precast shear wall component (2) are blocked and grouted in compartments to achieve the mechanical dry connection of the precast shear wall.

2. The construction method of the precast shear wall vertical dry connection structure as described in claim 1, characterized in that, the internal and external double-threaded nut (9) is composed of two semi-cylindrical ring-shaped half double-threaded nuts.

3. The construction method of the precast shear wall vertical dry connection structure as described in claim 2, characterized in that, grooves (10) are respectively arranged on the side walls on both sides of the open ends of the two semi-cylindrical ring-shaped half double-threaded nuts, and the grooves (10) of the two half double-threaded nuts are aligned and connected through the connecting pieces (11) arranged in the grooves (10).

4. The construction method of the precast shear wall vertical dry connection structure as described in claim 3, characterized in that, The groove (10) is an arc-shaped groove, and the connecting piece (11) is an arc-shaped plate.

5. The construction method of the precast shear wall vertical dry connection structure according to claim 3, characterized in that, The groove (10) opens on the top surface of the semi-double-threaded nut.

6. The construction method of the precast shear wall vertical dry connection structure according to claim 1, characterized in that, The number of the internal and external double-threaded nuts (9) is set to be at least two, the end faces of the adjacent internal and external double-threaded nuts (9) are flush, and the total length of all the internal and external double-threaded nuts (9) ≥ the length of the internal thread of the vertical force-bearing connecting steel pipe (4).

7. The construction method of the precast shear wall vertical dry connection structure according to claim 1, characterized in that, In the third step, before the curing and demoulding inspection of the precast shear wall component, the internal thread of the inner wall of the vertical force-bearing connecting steel pipe (4) should be subjected to a pull-out test according to the connection joint. The principle of the pull-out test is to randomly select at least two groups from the vertical force-bearing connecting steel bars (3), vertical force-bearing connecting steel pipes (4) and internal and external double-threaded nuts (9) in the same inspection lot when they enter the site; then bind the steel bar skeleton of the local shear wall; bind the vertical force-bearing connecting steel pipe (4) to the steel bar skeleton, and pour concrete to form a reinforced concrete specimen, cure until the concrete reaches final setting, insert the vertical force-bearing connecting steel bar (3) into the corresponding vertical force-bearing connecting steel pipe (4), and use the internal and external double-threaded nuts (9) to complete the fastening connection; set a ribbed structure on the outer wall of the vertical force-bearing connecting steel pipe (4); then conduct a pull-out test. When the vertical force-bearing connecting steel bar (3) is first pulled off, the pull-out requirement is met. When the vertical force-bearing connecting steel pipe (4) is first pulled out, increase the density and depth of the ribbed structure on the outer wall of the vertical force-bearing connecting steel pipe (4). When the vertical force-bearing connecting steel bar (3) is pulled out, increase the insertion depth of the vertical force-bearing connecting steel bar (3) until the pull-out requirement is met.

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