A bidirectional hollow slab composite shear wall with narrowed opening and stirrup connection
By setting openings and narrowing stirrup connections at the edge members of the shear wall, the reliability and integrity of the joints of the two-way hollow slab composite shear wall are improved, the design problems of the connection in the prior art are solved, the load-bearing capacity and seismic performance are improved, and the constructability and ductility design of the structure are realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANDONG AGRICULTURAL UNIVERSITY
- Filing Date
- 2025-06-24
- Publication Date
- 2026-05-26
AI Technical Summary
The existing double-sided hollow slab composite shear wall has difficulty meeting the reinforcement design requirements of cast-in-place edge members and double-sided hollow slab at the connection, resulting in poor overall shear wall integrity and insufficient load-bearing capacity and seismic performance.
The design of opening-narrowing stirrup connection is adopted. By setting opening-narrowing stirrups at the edge members at both ends of the shear wall, the reliability of the joint is improved, and the constraint effect on the core concrete is gradually reduced under large horizontal displacement, forming a vertical energy dissipation zone and avoiding shear brittle failure.
It improves the integrity, load-bearing capacity and seismic performance of the two-way hollow slab composite shear wall, realizes the constructability and ductility design of the structure, reduces the amount of materials used, and reduces the complexity and cost of construction.
Smart Images
Figure CN224281669U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of concrete composite shear wall building structure in civil engineering, specifically relating to a bidirectional hollow slab composite shear wall with narrowed opening and stirrup connection. Background Technology
[0002] Currently, shear wall structures are mainly used in high-rise and mid-rise residential buildings. However, composite shear wall structures significantly reduce on-site wet work, improve construction speed and quality, and increase the effective utilization rate of building materials compared to traditional cast-in-place shear walls. In addition, composite shear wall structures also feature standardized production, modularization, and industrialized construction, enabling the formation of a standardized system from design to construction, which aligns with the development direction of building industrialization.
[0003] As one of the configurations for precast wall panels, the bidirectional void design effectively avoids problems such as insufficient compaction and cavities in the post-cast concrete due to its vertical and horizontal continuity. Furthermore, the interaction between the concrete connecting ribs in the central cavity and the post-cast concrete allows the cast-in-place and precast layers to work together. For bidirectional void composite shear walls, there are two methods: those with extended horizontal reinforcement and those without. While extended horizontal reinforcement ensures the reliability of the connection at the confined edge members and the overall integrity of the shear wall, it increases construction complexity during precast component production and transportation, and can lead to yielding of some extended reinforcement, or even irreversible permanent deformation, making it difficult to achieve the intended design goals. On the other hand, if traditional rectangular closed stirrups are still used for the non-extended horizontal reinforcement method, it is difficult to meet the reinforcement design requirements at the connection between the cast-in-place edge members and the bidirectional void slab, failing to guarantee the constructability of the composite shear wall, especially the reliability of the joints, resulting in poor overall shear wall integrity and consequently reducing the shear wall's load-bearing capacity and seismic performance.
[0004] Therefore, there is an urgent need to design a new connection design to realize the construction of bidirectional hollow slab composite shear walls and meet the load-bearing and seismic requirements of this type of shear wall. Summary of the Invention
[0005] To address the difficulty in meeting the reinforcement design requirements at the connection between cast-in-place edge members and bidirectional vacuum slabs, this utility model provides a bidirectional vacuum slab composite shear wall with narrowed-opening stirrups. By setting narrowed-opening stirrups corresponding to the horizontal holes of the bidirectional vacuum slab at the edge members at both ends of the shear wall, the special structure of the narrowed-opening stirrups improves the reliability of the joint and the reinforcement design structure at the connection between the cast-in-place edge members and the bidirectional vacuum slab. This effectively improves the integrity, bearing capacity, and seismic performance of the bidirectional vacuum slab composite shear wall, and satisfies the constructability requirements of the new bidirectional vacuum slab composite shear wall.
[0006] As a secondary improvement, existing shear walls, as the main lateral resisting components, suffer from excessively high strength and stiffness in their main materials such as steel reinforcement and concrete, relying primarily on the material strength itself to resist external loads. The bidirectional hollow slab composite shear wall with opening-narrowing stirrups obtained through this invention, where the opening-narrowing stirrups gradually narrow from the closed end to the open end, gradually reduces the constraint effect of the opening-narrowing stirrups on the core concrete. This effect is manifested under significant horizontal lateral displacement, with the maximum stress location gradually shifting towards the open end of the opening-narrowing stirrups. This results in a vertical energy dissipation zone between the middle of the opening-narrowing stirrups and the open end, leading to micro-slippage at the joint and preventing brittle shear failure. This achieves an innovative connection method and ductile design for shear walls.
[0007] This utility model first provides a bidirectional hollow slab composite shear wall with opening and narrowing stirrups. The bidirectional hollow slab composite shear wall includes a bidirectional hollow slab and post-cast concrete inside and at both ends. Edge members are provided on both sides of the bidirectional hollow slab and at the ends of the post-cast concrete. The bidirectional hollow slab includes a first concrete slab and a second concrete slab arranged opposite to each other. The edge members include edge member longitudinal bars embedded in the post-cast concrete and opening and narrowing stirrups arranged in the horizontal direction. Multiple opening and narrowing stirrups are distributed in the vertical direction and are symmetrically arranged inside the post-cast concrete at both ends of the bidirectional hollow slab composite shear wall.
[0008] The bidirectional hollow slab composite shear wall is equipped with various types of steel bars, which together with the bidirectional hollow slab and the post-cast concrete form the bidirectional hollow slab composite shear wall.
[0009] The first concrete slab has a slightly longer lateral length than the second concrete slab. After installation, the first and second concrete slabs are symmetrically arranged on the outside of the wall.
[0010] One end of the narrowing stirrup is closed and has two opposite corners, while the other end is open. The open end has an outward bending section and a straight section after bending. The longitudinal bars of the inner edge members and the longitudinal bars of the outer edge members are respectively located inside the bending section and the straight section after bending and at the two corners of the closed end of the narrowing stirrup. Between the open end and the closed end, there are also two middle edge member longitudinal bars connected by a first horizontal tie bar. The longitudinal bars of the outer edge members and the longitudinal bars of the middle edge members are tied and fixed at the contact points with the narrowing stirrup.
[0011] More specifically, the narrowing stirrup is made by continuously bending a single steel bar, including a longitudinal section and horizontal sections connected to both ends of the longitudinal section, and gradually narrows inward from the closed end to the open end; the other end of the horizontal section is bent outward to form a bent section and a straight section after bending, forming a narrowing stirrup structure.
[0012] Preferably, one end of the horizontal section of the narrowing stirrup is connected to the longitudinal section and forms an angle of 70-80° with the longitudinal section. The other end of the horizontal section is bent outward to form a bent section and a straight section after bending. The length of the straight section after bending is the larger of 10 times the diameter of the narrowing stirrup and 75 mm.
[0013] The diameter of each segment of the narrowing stirrup is consistent and gradually narrows towards the opening end.
[0014] The included angle and the length of the straight section after the bend are set within the above range. The purpose is to standardize the production of the narrowed-opening stirrups and to effectively control the confinement effect of the narrowed-opening stirrups on the core area concrete through the included angle.
[0015] The longitudinal reinforcement of the edge member includes an inner edge member longitudinal reinforcement, a middle edge member longitudinal reinforcement, and an outer edge member longitudinal reinforcement. The inner edge member longitudinal reinforcement is located in the area enclosed by the bent section, the straight section after the bend, and the horizontal section of the opening narrowing stirrup. The outer edge member longitudinal reinforcement is located at the angle between its horizontal section and longitudinal section. The middle edge member longitudinal reinforcement is located inside the horizontal section and abuts against the horizontal section. The contact points of the outer edge member longitudinal reinforcement, the middle edge member longitudinal reinforcement, and the opening narrowing stirrup are fixed by binding with metal wire. The inner edge member longitudinal reinforcement is tightened and fixed by the hook of the opening narrowing stirrup.
[0016] The longitudinal bars of the central edge members are connected by a first horizontal tie bar, and the longitudinal bars of the central edge members abut against the horizontal section of the opening narrowing stirrup and are fixed by binding with metal wire.
[0017] Preferably, there are two longitudinal ribs in the middle edge members on each side of the bidirectional vacuum plate, and a first horizontal tie bar is set corresponding to the longitudinal ribs in the middle edge members. The first horizontal tie bar corresponds one-to-one with the opening narrowing stirrup. The longitudinal ribs in the middle edge members are tied and fixed to the first horizontal tie bar inside the opening narrowing stirrup.
[0018] Preferably, multiple sets of concrete ribs are arranged between the two opposite first and second concrete slabs of the bidirectional vacuum slab in the horizontal and vertical directions. Preferably, the concrete ribs are arranged at fixed intervals in both the horizontal and vertical directions. Vertical holes are formed between the concrete ribs in the horizontal direction, and horizontal holes are formed between the concrete ribs in the vertical direction. One end of the bent section of the narrowed-opening stirrup extends into the horizontal hole at the end of the bidirectional vacuum slab. The longitudinal reinforcement of the inner edge member is arranged in the first vertical hole at both ends of the transverse direction of the bidirectional vacuum slab. One side of the longitudinal section of the narrowed-opening stirrup, the longitudinal reinforcement of the middle edge member, and the longitudinal reinforcement of the outer edge member are all arranged on the outer side of both ends of the bidirectional vacuum slab.
[0019] The first horizontal tie bar at the edge member is used in conjunction with the opening narrowing stirrup to improve the restraint on the steel reinforcement of the shear wall edge member and the concrete of the core area, and to improve the problem that the longitudinal reinforcement of the edge member is detached and it is difficult to exert its tensile strength under large earthquake action.
[0020] More preferably, the number of horizontal holes is ≥7. Among the 2-3 horizontal holes from top to bottom and the 2-3 horizontal holes from bottom to top, each horizontal hole has two sets of opening narrowing stirrups on each side of its lateral side, and the remaining horizontal holes have one set of opening narrowing stirrups on each side of their lateral side.
[0021] Since the upper and lower ends of the wall are subjected to greater forces when shear failure occurs in the actual structure, this utility model improves the load-bearing capacity of the wall by setting up a stirrup reinforcement zone at the upper and lower ends of the bidirectional vacuum plate and setting multiple sets of corresponding narrowing stirrups in the horizontal holes at the top and bottom.
[0022] More preferably, the number of vertical holes is ≥3, including two outermost first vertical holes at the two ends and at least one second vertical hole between the two first vertical holes. The first vertical holes are provided with inner edge longitudinal ribs along the vertical direction. Each second vertical hole is provided with two wall distribution longitudinal ribs opposite each other along the vertical direction. The second horizontal tie connects the two opposite wall distribution longitudinal ribs inside the second vertical hole. The contact point between the wall distribution longitudinal ribs inside the second vertical hole and the second horizontal tie is fixed with metal wire.
[0023] The longitudinal reinforcement of the edge member and the wall distribution longitudinal reinforcement provided in the second vertical hole all have their top ends protruding through the top surface of the bidirectional vacuum plate.
[0024] Through the interaction between the concrete ribs and the surrounding cast-in-place concrete, one end of the bent section of the narrowing stirrup extends into the horizontal hole of the two-way slab, connecting with the internal wall, ensuring the integrity of the edge members and the internal wall, and jointly resisting seismic forces under small lateral displacements. As the narrowing stirrup gradually narrows towards the open end, its restraining effect on the core concrete gradually decreases. This effect becomes apparent under larger horizontal lateral displacements, with the maximum stress location gradually shifting towards the open end of the narrowing stirrup, resulting in a vertical energy dissipation zone between the middle of the narrowing stirrup and the open end, leading to slight slippage at the joints. This avoids significant shear failure and protects the edge members of the structure. After installation, the various reinforcing bars of the edge members are integrally cast-in-place to form the cast-in-place concrete.
[0025] Preferably, tie bars are embedded inside the concrete ribs, and horizontal steel bars are correspondingly provided in the first and second concrete slabs. The tie bars are integrally connected with the horizontal steel bars, and the horizontal steel bars are embedded inside the first and second concrete slabs. Their function is to connect the tie bars in the concrete ribs together with the horizontal steel bars in the first and second concrete slabs, so that the steel bars in the bidirectional hollow slab are woven together and share the load.
[0026] Preferably, a wire mesh is provided inside the first concrete slab and the second concrete slab, and the wire mesh is embedded inside the first concrete slab and the second concrete slab.
[0027] The steel wire mesh is used to enhance the crack resistance of the bidirectional vacuum plate and prevent cracks from occurring during transportation, which would affect the normal use of the bidirectional vacuum plate.
[0028] The bidirectional vacuum slab is prefabricated and is made by integrally casting concrete and using a bidirectional core-pulling method.
[0029] Furthermore, the opening narrowing stirrup is not only applicable to the planar structural system of the straight rectangular section shear wall, but also to the L-shaped corner wall with spatial stress effect. Specifically, longitudinal bars and rectangular closed stirrups are added in the out-of-plane direction of the longitudinal bars of the edge members. The longitudinal bars of the outer edge members and the longitudinal bars of the middle edge members are limited at the two corners of the rectangular closed stirrup, and the additional longitudinal bars limit the other two corners of the rectangular closed stirrup.
[0030] Open-ended narrowing stirrups can be used in conjunction with rectangular closed stirrups. In the main direction, the method of using open-ended narrowing stirrups is consistent with the planar structural system of a T-shaped rectangular section shear wall. In the out-of-plane direction, rectangular closed stirrups are used. The combined use of open-ended narrowing stirrups, traditional rectangular closed stirrups, and longitudinal reinforcement of edge members can also ensure the load-bearing capacity and ductility of the shear wall.
[0031] The construction method for the bidirectional hollow slab composite shear wall with narrowed opening and stirrup connection is as follows:
[0032] First, set the longitudinal reinforcement of the wall distribution and the longitudinal reinforcement of the edge members. Then, hoist the bidirectional vacuum slab onto the longitudinal reinforcement of the wall distribution and the edge members. During the process, the position of the vertical hole should be kept in line with the corresponding longitudinal reinforcement of the wall distribution or the longitudinal reinforcement of the inner edge member. During hoisting, symmetrically set the opening narrowing stirrups in the edge members on both sides of the end of the bidirectional vacuum slab superimposed shear wall. When hoisting the bidirectional vacuum slab, insert the opening narrowing stirrups into the horizontal holes at the end of the bidirectional vacuum slab. Set the opening narrowing stirrups at the corresponding positions of the edge member longitudinal reinforcements. That is, the inner edge member longitudinal reinforcement is limited to the area between the bent section, the straight section after the bend and the horizontal section of the opening narrowing stirrup. The middle edge member longitudinal reinforcement connected by the first horizontal tie is located inside the horizontal section of the opening narrowing stirrup and abuts against the horizontal section. The outer edge member longitudinal reinforcement is set at the angle between the horizontal section and the longitudinal section of the opening narrowing stirrup. After the bidirectional vacuum slab is hoisted, tie and fix the opening narrowing stirrups to the edge member longitudinal reinforcements. Finally, pour concrete integrally at the end edge members and the cavity of the bidirectional vacuum slab.
[0033] More specifically, the construction method for the bidirectional hollow slab composite shear wall with narrowed opening and stirrup connection includes the following steps:
[0034] 1) The bidirectional vacuum slab is used as the side formwork of the shear wall. The bidirectional vacuum slab is provided with concrete ribs and horizontal and vertical holes are formed between the concrete ribs.
[0035] As a preferred option, the two-way hollow slab has pre-installed horizontal steel bars and tie bars to resist shear failure, while also meeting the requirements for transportation and hoisting. Furthermore, the two-way hollow slab can serve as formwork, reducing the amount of formwork used, especially reducing the use of traditional wooden formwork.
[0036] 2) In the second vertical hole of the bidirectional vacuum slab, the wall distribution longitudinal reinforcement is set. The inner edge member longitudinal reinforcement is set in the first vertical hole at both ends. The middle edge member longitudinal reinforcement and the outer edge member longitudinal reinforcement are set on the outer side at both ends. The two opposite middle edge member longitudinal reinforcements are connected and tied together by the first horizontal tie bar. Then, the opening narrowing stirrups are set at both ends of the horizontal direction. The opening narrowing stirrup is open at one end and closed at the other end. The open end includes a bent section and a straight section after bending. The inner edge member longitudinal reinforcement is limited to the bent section and the straight section after bending. The middle edge member longitudinal reinforcement and the outer edge member longitudinal reinforcement are respectively set at the middle of the horizontal section of the opening narrowing stirrup and at the two corners of the closed end. The outer edge member longitudinal reinforcement, the middle edge member longitudinal reinforcement and the opening narrowing stirrup are tied together at the contact point. The inner edge member longitudinal reinforcement is tightened and fixed by the hook of the opening narrowing stirrup.
[0037] By setting longitudinal reinforcement bars distributed within the wall and longitudinal reinforcement bars of the edge members at the vertical holes and edge members of the bidirectional vacuum slab, it is helpful to resist bending failure. The open ends of the narrowed stirrups set at both ends extend into the first vertical hole of the bidirectional vacuum slab, and are connected to the longitudinal reinforcement bars of the inner edge members of the first vertical hole through their bent sections and straight sections after bending, thus realizing the effective connection between the edge members and the bidirectional vacuum slab.
[0038] 3) Concrete is poured inside and at both ends of the two-way hollow slab to obtain a two-way hollow slab composite shear wall with narrowed openings and stirrups.
[0039] The edge members and the two-way slab can share the load collaboratively under the connection of the narrowing stirrups. The two-way slab and the post-cast concrete work together through the interaction between the concrete ribs and the surrounding concrete. As the narrowing stirrups gradually narrow towards the open end, the constraint effect of the narrowing stirrups on the core concrete gradually decreases. This effect is manifested under large horizontal lateral displacement, and the location of maximum stress in the structure gradually shifts towards the open end of the narrowing stirrups, resulting in slight slippage at the joint, forming a vertical energy dissipation channel, avoiding shear brittle failure, and providing a certain degree of protection for the edge members.
[0040] The first horizontal tie bar is tied between the two longitudinal bars of the middle edge member and the corresponding opening narrowing stirrup, and the opening narrowing stirrup is tied and fixed at the contact point with the longitudinal bars of the outer edge member and the longitudinal bars of the middle edge member.
[0041] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0042] This invention provides a bidirectional hollow slab composite shear wall with opening and narrowing stirrups. By setting opening and narrowing stirrups within the edge members at both ends of the bidirectional hollow slab composite shear wall, with one end of the opening and narrowing stirrups extending into the bidirectional hollow slab, and setting longitudinal reinforcement of the edge members at corresponding positions of the opening and narrowing stirrups, this invention solves the construction difficulties of bidirectional hollow slab composite shear walls and achieves a balance between the constructability, good economy, and seismic performance of the novel composite shear wall structure.
[0043] Furthermore, compared to the additional U-shaped reinforcement connection method used for unreinforced precast wall panels and cast-in-place sections in engineering, the connection method using narrowed-opening stirrups can reduce the amount of steel used in the structure, save material costs, and contribute to the low-carbon and green development of building structures.
[0044] Furthermore, by setting longitudinal reinforcement of edge members at the corresponding positions of the narrowing stirrups and using them in conjunction with tie bars, the bearing capacity of the edge restraint members of the two-way hollow slab composite shear wall structure can be effectively ensured, thus guaranteeing an effective path for the transmission of structural forces.
[0045] Furthermore, in the bidirectional hollow slab composite shear wall with opening-narrowing stirrups, the confinement effect of the opening-narrowing stirrups on the core concrete gradually decreases as the opening-narrowing stirrups gradually narrow towards the opening end. This effect is manifested under large horizontal lateral displacement, and the position of maximum stress in the structure gradually shifts towards the opening end of the opening-narrowing stirrups, resulting in the formation of a vertical energy dissipation zone between the middle of the opening-narrowing stirrups and the opening end. This leads to slight slippage at the joint, realizing the innovation of shear wall connection method and ductile design, as well as effective control of failure mode and energy dissipation mode. Attached Figure Description
[0046] Figure 1 This is a three-dimensional schematic diagram of the double-sided hollow slab composite shear wall with narrowed opening and stirrup connection before and after casting, according to the present invention. Figure 1 In this context, A represents the area before concrete pouring. Figure 1 In this context, B represents the area after the concrete has been poured.
[0047] Figure 2 This is an enlarged view of the bottom of the bidirectional hollow slab composite shear wall with narrowed opening and stirrup connection according to this utility model.
[0048] Figure 3 This is a plan view of the reinforcement of a two-way hollow slab composite shear wall with narrowed opening and stirrup connection according to this utility model.
[0049] Figure 4 This is a three-dimensional schematic diagram of the bidirectional vacuum plate of this utility model;
[0050] Figure 5 This is a schematic diagram of the cross-sectional reinforcement of the bidirectional vacuum slab of this utility model;
[0051] Figure 6 for Figure 5 A cross-sectional view along the AA direction;
[0052] Figure 7 The bidirectional vacuum plate of this utility model is along Figure 6 Cross-sectional views in the BB direction (A) and CC direction (B);
[0053] Figure 8 A in the figure is a three-dimensional schematic diagram of the opening narrowing stirrup of this utility model; Figure 8 B in the figure is a physical picture of the opening narrowing stirrup of this utility model;
[0054] Figure 9 The hysteresis curve of the two-way hollow slab composite shear wall with narrowed opening and stirrup connection is shown in the test of the seismic performance of this utility model.
[0055] Figure 10 This is a three-dimensional schematic diagram of a bidirectional hollow slab composite shear wall with an L-shaped wall, featuring a narrowed opening and stirrup connection, according to the present invention.
[0056] Figure 11 for Figure 10 A close-up view of the bottom section.
[0057] In the diagram: 1 is a two-way slab with a vacuum core; 11-1 is the first concrete slab; 11-2 is the second concrete slab; 12 is a concrete rib; 13 is a tie bar; 14 is a horizontal reinforcing bar; 15 is the second vertical hole; 16 is the first vertical hole; 2 is the post-cast concrete; 3 is the opening-narrowing stirrup; 31 is the longitudinal section; 32 is the horizontal section; 33 is the bent section; 34 is the straight section after bending; 4 is the longitudinal reinforcement of the edge member; 41 is the longitudinal reinforcement of the inner edge member; 42 is the longitudinal reinforcement of the middle edge member; 43 is the longitudinal reinforcement of the outer edge member; 5 is the first horizontal tie bar; 51 is the second horizontal tie bar; 6 is a rectangular closed stirrup. Detailed Implementation
[0058] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0059] In this utility model, the direction of the extension of the longitudinal reinforcement 4 of the edge member is taken as the vertical direction, and the direction of the extension of the horizontal reinforcement 14 is taken as the horizontal direction.
[0060] In this scheme, the out-of-plane direction refers to the vertical direction of the first concrete slab 11-1 and the second concrete slab 11-2.
[0061] Structural Example 1
[0062] A type of double-sided hollow slab composite shear wall with narrowed opening and stirrup connection, the resulting double-sided hollow slab composite shear wall with narrowed opening and stirrup connection after construction is as follows: Figure 1-7 As shown, the bidirectional hollow slab composite shear wall includes a bidirectional hollow slab 1 and post-cast concrete 2 inside and at both ends, with edge members provided at both ends of the bidirectional hollow slab 1 and the ends of the post-cast concrete 2.
[0063] The bidirectional evacuation plate 1 includes a first concrete plate 11-1 and a second concrete plate 11-2 arranged opposite to each other.
[0064] The transverse length of the first concrete slab 11-1 is slightly greater than that of the second concrete slab 11-2. After installation, the first concrete slab 11-1 and the second concrete slab 11-2 are symmetrically arranged on the outside of the wall.
[0065] The bidirectional hollow slab composite shear wall is equipped with various types of steel bars, which together with the bidirectional hollow slab 1 and the post-cast concrete 2 constitute the bidirectional hollow slab composite shear wall.
[0066] The edge members include edge member longitudinal bars 4 embedded in the post-cast concrete 2 and opening narrowing stirrups 3 arranged in the horizontal direction. Multiple opening narrowing stirrups 3 are distributed in the vertical direction and are symmetrically arranged in the post-cast concrete 2 at both ends of the two-way hollow slab composite shear wall.
[0067] One end of the narrowing stirrup 3 is closed and has two opposite corners, while the other end is open. The open end has an outward bending section 33 and a straight section 34 after bending. The inner edge member longitudinal bar 41 and the outer edge member longitudinal bar 43 are respectively located inside the bending section 33 and the straight section 34 after bending and at the two corners of the closed end of the narrowing stirrup 3. Preferably, two middle edge member longitudinal bars 42 are connected by a first horizontal tie bar 5 between the open end and the closed end. The outer edge member longitudinal bar 43 and the middle edge member longitudinal bar 42 are tied and fixed at the contact point with the narrowing stirrup 3.
[0068] like Figure 8 A and Figure 8 As shown in B, the narrowing stirrup 3 is made by continuously bending a single steel bar, including a longitudinal section 31 and horizontal sections 32 connected to both ends of the longitudinal section 31, and gradually narrows inward from the closed end to the open end; the other end of the horizontal section 32 is bent outward to form a bent section 33 and a straight section 34 after bending, forming a narrowing stirrup structure.
[0069] The edge member longitudinal reinforcement 4 includes an inner edge member longitudinal reinforcement 41, a middle edge member longitudinal reinforcement 42, and an outer edge member longitudinal reinforcement 43. The inner edge member longitudinal reinforcement 41 is located in the area enclosed by the bent section 33, the straight section 34 after bending, and the horizontal section 32 of the opening narrowing stirrup 3. The outer edge member longitudinal reinforcement 43 is located at the angle between its horizontal section 32 and its longitudinal section 31. The middle edge member longitudinal reinforcement 42 is located inside the horizontal section 32 and abuts against the horizontal section 32. The contact points of the outer edge member longitudinal reinforcement 43, the middle edge member longitudinal reinforcement 42, and the opening narrowing stirrup 3 are fixed by binding with metal wire. The inner edge member longitudinal reinforcement 41 is tightened and fixed by the hook of the opening narrowing stirrup 3.
[0070] The longitudinal ribs 42 of the middle edge member are connected by the first horizontal tie bar 5, and the longitudinal ribs 42 of the middle edge member abut against the horizontal section 32 of the opening narrowing stirrup 3 and are fixed by binding with metal wire.
[0071] The bidirectional vacuum slab 1 has two longitudinal ribs 42 in the middle edge component on each side. A first horizontal tie bar 5 is set corresponding to the longitudinal rib 42 in the middle edge component. The first horizontal tie bar 5 corresponds one-to-one with the opening narrowing stirrup 3. The longitudinal rib 42 in the middle edge component is tied and fixed to the first horizontal tie bar 5 inside the opening narrowing stirrup 3.
[0072] Multiple sets of concrete ribs 12 are arranged horizontally and vertically between the two opposing first concrete slabs 11-1 and second concrete slabs 11-2 of the bidirectional vacuum slab 1. Preferably, the concrete ribs 12 are arranged at fixed intervals in both the horizontal and vertical directions. Vertical holes are formed between the concrete ribs 12 in the horizontal direction, and horizontal holes are formed between the concrete ribs 12 in the vertical direction. One end of the bent section 33 of the narrowed-opening stirrup 3 extends into the horizontal hole at the end of the bidirectional vacuum slab 1. The longitudinal reinforcement 41 of the inner edge member is arranged in the first vertical hole 16 at both ends of the bidirectional vacuum slab 1 in the horizontal direction. One side of the longitudinal section 31 of the narrowed-opening stirrup 3, the longitudinal reinforcement 42 of the middle edge member, and the longitudinal reinforcement 43 of the outer edge member are all arranged on the outer side of both ends of the bidirectional vacuum slab 1.
[0073] The first horizontal tie bar 5 at the edge member is used in conjunction with the opening narrowing stirrup 3 to improve the restraint on the steel reinforcement of the edge member and the concrete of the core area of the shear wall, and to improve the problem that the longitudinal reinforcement 4 of the edge member is detached under large earthquake action and it is difficult to exert its tensile strength.
[0074] As a further preferred embodiment, the number of horizontal holes is ≥7. Among the 2-3 horizontal holes from top to bottom and the 2-3 horizontal holes from bottom to top, each horizontal hole has two sets of opening narrowing stirrups 3 on each side of its lateral direction. The remaining horizontal holes have one set of opening narrowing stirrups 3 on each side of their lateral direction.
[0075] Since the upper and lower ends of the wall are subjected to greater forces when shear failure occurs in the actual structure, this utility model improves the wall's load-bearing capacity by setting up stirrup reinforcement zones at the upper and lower ends of the bidirectional vacuum plate 1 and setting multiple sets of corresponding narrowing stirrups 3 in the horizontal holes at the top and bottom.
[0076] As a further preferred embodiment, the number of vertical holes is ≥3, including two outermost first vertical holes 16 at both ends and at least one second vertical hole 15 between the two first vertical holes 16. The first vertical holes 16 are provided with inner edge members longitudinal ribs 41 along the vertical direction. Each second vertical hole 15 is provided with two wall distribution longitudinal ribs opposite each other along the vertical direction. The second horizontal tie rib 51 connects the two opposite wall distribution longitudinal ribs inside the second vertical hole 15. The contact points between the wall distribution longitudinal ribs inside the second vertical hole 15 and the second horizontal tie rib 51 are tied and fixed with metal wire.
[0077] In this embodiment, a total of 5 vertical holes are provided, namely the two outermost first vertical holes 16 at the ends, and the three second vertical holes 15 between the two first vertical holes 16.
[0078] The longitudinal reinforcement 4 of the edge member and the longitudinal reinforcement distributed inside the second vertical hole 15 have their top ends protruding through the top surface of the bidirectional vacuum plate 1.
[0079] Through the interaction between the concrete rib 12 and the surrounding post-cast concrete 2, one end of the bent section 33 of the opening narrowing stirrup 3 extends into the horizontal hole of the two-way slab 1 and connects with the inner wall to ensure the integrity of the edge members and the inner wall, and to cooperate in resisting seismic forces with small lateral displacement.
[0080] As the narrowing stirrups 3 gradually narrow towards the open end, their restraining effect on the core concrete gradually decreases. This effect is manifested under significant horizontal lateral displacement, causing the location of maximum stress in the structure to gradually shift towards the open end of the narrowing stirrups 3. This results in a vertical energy dissipation zone forming between the middle of the narrowing stirrups 3 and the open end, leading to slight slippage at the joints. This avoids significant shear failure in the structure and effectively controls the failure mode and energy dissipation method of the composite shear wall.
[0081] After the various types of reinforcing bars of the edge components are installed, they are cast into post-concrete through a single integral cast-in-place process.
[0082] Tie bars 13 are embedded inside the concrete rib 12, and horizontal steel bars 14 are correspondingly provided in the first concrete slab 11-1 and the second concrete slab 11-2. The tie bars 13 and the horizontal steel bars 14 are integrally connected.
[0083] The tie bar 13 is embedded in the concrete rib 12 and is connected to the horizontal steel bar 14 in the first concrete slab 11-1 and the second concrete slab 11-2. The horizontal steel bar 14 is embedded inside the first concrete slab 11-1 and the second concrete slab 11-2. Its function is to connect the tie bar 13 in the concrete rib 12 with the horizontal steel bar 14 in the first concrete slab 11-1 and the second concrete slab 11-2, so that the steel bars in the bidirectional vacuum slab 1 are woven together and share the force.
[0084] A wire mesh is installed inside the first concrete slab 11-1 and the second concrete slab 11-2. The wire mesh is embedded inside the first concrete slab 11-1 and the second concrete slab 11-2.
[0085] The steel wire mesh is used to enhance the crack resistance of the bidirectional vacuum plate 1 and prevent cracks from occurring during transportation, which would affect the normal use of the bidirectional vacuum plate 1.
[0086] The bidirectional vacuum slab 1 is prefabricated and is made by integrally casting concrete and by bidirectional core extraction.
[0087] One end of the horizontal segment 32 of the narrowing stirrup 3 is connected to the longitudinal segment 31 and forms an angle of about 70° to 80° with the longitudinal segment 31. The other end of the horizontal segment 32 is bent outward to form a bent segment 33 and a straight segment 34 after bending. The length of the straight segment 34 after bending is the larger of 10 times the diameter of the narrowing stirrup 3 and 75 mm.
[0088] The diameter of each segment of the narrowing stirrup 3 is consistent and gradually narrows towards the opening end.
[0089] The included angle and the length of the straight section 34 after the bend are set within the above range. The purpose is to standardize the production of the narrowing stirrup 3 and to effectively control the confinement effect of the narrowing stirrup 3 on the core area concrete through the included angle. It is also required that the length of the straight section 34 after the bend of the narrowing stirrup 3 provides sufficient anchorage length and avoids material waste.
[0090] The seismic performance hysteresis curve of the "I-shaped" section of the bidirectional hollow slab composite shear wall with narrowed opening and stirrup connection described in this utility model is as follows: Figure 9 As shown.
[0091] The construction method for the bidirectional hollow slab composite shear wall with narrowed opening and stirrup connection is as follows:
[0092] First, set the wall distribution longitudinal reinforcement and edge member longitudinal reinforcement 4. Then, hoist the bidirectional vacuum slab 1 onto the wall distribution longitudinal reinforcement and edge member longitudinal reinforcement 4. During the process, the position of the vertical hole is kept in correspondence with the corresponding wall distribution longitudinal reinforcement or inner edge member longitudinal reinforcement 41. During hoisting, symmetrically set the opening narrowing stirrups 3 in the edge members on both sides of the end of the bidirectional vacuum slab superimposed shear wall. When hoisting the bidirectional vacuum slab 1, insert the opening narrowing stirrups 3 from the horizontal hole at the end of the bidirectional vacuum slab 1. The inner edge member longitudinal reinforcement 41 is limited to the area between the bent section 33, the straight section 34 after bending and the horizontal section 32 of the opening narrowing stirrup 3. The middle edge member longitudinal reinforcement 42 is located in the area between the bent section 33, the straight section 34 after bending and the horizontal section 32 of the opening narrowing stirrup 3. The outer edge member longitudinal reinforcement 43 is located at the angle between the horizontal section 32 and the longitudinal section 31 of the opening narrowing stirrup 3. The first horizontal tie bar 5 is tied between the two middle edge member longitudinal reinforcements 42 and the opening narrowing stirrup 3. After the bidirectional vacuum plate 1 is hoisted, the opening narrowing stirrup 3 is tied and fixed with metal wire at the contact point between the outer edge member longitudinal reinforcement 43 and the middle edge member longitudinal reinforcement 42. The inner edge member longitudinal reinforcement 41 is tightened and fixed by the hook of the opening narrowing stirrup 3. Finally, concrete is poured at the end edge member and the cavity of the bidirectional vacuum plate 1.
[0093] Structural Example 2
[0094] The opening narrowing stirrup 3 described in this utility model is not only applicable to the planar structural system of shear wall with straight rectangular cross section, but also applicable to L-shaped corner wall with spatial force effect.
[0095] like Figure 10 and Figure 11 As shown, the opening narrowing stirrup 3 can be used in conjunction with the rectangular closed stirrup 6. In the main direction, the method of using the opening narrowing stirrup 3 is consistent with the planar structural system of the straight rectangular section shear wall described in structural embodiment 1. The rectangular closed stirrup 6 is used in the out-of-plane direction. The longitudinal reinforcement and the rectangular closed stirrup 6 are additionally set in the out-of-plane direction of the edge member longitudinal reinforcement 4. The outer edge member longitudinal reinforcement 43 and the middle edge member longitudinal reinforcement 42 are limited at the two corners of the rectangular closed stirrup 6, and the additional longitudinal reinforcement limits the other two corners of the rectangular closed stirrup 6. The length of the rectangular closed stirrup 6 is greater than the span of the opening narrowing stirrup 3 in the out-of-plane direction.
[0096] The longitudinal reinforcement 43 of the outer edge member and the longitudinal reinforcement 42 of the middle edge member on one side of the bidirectional vacuum plate 1 are limited at the two corners of the rectangular closed stirrup 6, and additional longitudinal reinforcement is provided to limit the remaining two corners of the rectangular closed stirrup 6.
[0097] The combined use of narrowing stirrups 3, traditional rectangular closed stirrups 6, and longitudinal reinforcement 4 of edge members can ensure the bearing capacity and ductility of the shear wall.
[0098] Experimental Example 1
[0099] The seismic performance of the double-sided hollow slab composite shear wall with narrowed opening and stirrup connection in Structural Embodiment 1 was tested. The test method referred to the People's Republic of China industry standard "Code for Seismic Testing of Buildings" JGJ / T 101-2015, which included low-cycle cyclic load tests. The test results are as follows. Figure 9 As shown.
[0100] from Figure 9 It can be seen from the test that the hysteresis curve obtained is relatively full, with obvious elastic stage, yield stage and failure stage, and all characteristic points meet the requirements of the current "Standard for Design of Concrete Structures" GB / T 50010.
[0101] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any equivalent substitutions or modifications made by those skilled in the art within the spirit and principle of the present utility model without any creative effort shall be included within the protection scope of the present utility model.
Claims
1. A bidirectional hollow slab composite shear wall with narrowing opening and stirrup connection, the bidirectional hollow slab composite shear wall comprising a bidirectional hollow slab (1) and post-cast concrete (2) inside and at both ends, edge members provided on both sides of the bidirectional hollow slab (1) and at the ends of the post-cast concrete (2), the bidirectional hollow slab (1) comprising a first concrete slab (11-1) and a second concrete slab (11-2) arranged opposite to each other, characterized in that: The edge members include edge member longitudinal bars (4) embedded in the post-cast concrete (2) and opening narrowing stirrups (3) arranged in the horizontal direction. Multiple opening narrowing stirrups (3) are distributed in the vertical direction. The opening narrowing stirrups (3) are symmetrically arranged inside the post-cast concrete (2) at both ends of the two-way hollow slab composite shear wall. One end of the narrowing stirrup (3) is closed and has two opposite corners, while the other end is open. The open end has an outward bending section (33) and a straight section after bending (34). The inner edge member longitudinal bar (41) and the outer edge member longitudinal bar (43) are respectively limited to the inside of the bending section (33), the straight section after bending (34) and the two corners of the closed end of the narrowing stirrup (3). Two middle edge member longitudinal bars (42) are connected by a first horizontal tie bar (5) between the open end and the closed end. The outer edge member longitudinal bar (43) and the middle edge member longitudinal bar (42) are tied and fixed at the contact point with the narrowing stirrup (3).
2. The dual-stage evacuation panel composite shear wall with opening-narrowing tie connection according to claim 1, wherein: The opening narrowing stirrup (3) includes a longitudinal section (31) and a horizontal section (32) connected to both ends of the longitudinal section (31), and gradually narrows inward from the closed end to the open end; the other end of the horizontal section (32) bends outward to form a bent section (33) and a straight section after bending (34).
3. The dual-stage evacuation panel composite shear wall with opening narrowing tie connection according to claim 2, wherein: One end of the horizontal segment (32) of the opening narrowing stirrup (3) is connected to the longitudinal segment (31) and forms an angle of 70-80° with the longitudinal segment (31). The other end of the horizontal segment (32) bends outward to form a bent segment (33) and a straight segment (34) after bending. The length of the straight segment (34) after bending is the larger of 10 times the diameter of the opening narrowing stirrup (3) and 75 mm. The diameter of each segment of the opening narrowing stirrup (3) is consistent.
4. The bidirectional hollow slab composite shear wall with narrowed opening and stirrup connection according to any one of claims 1-3, characterized in that: The edge member longitudinal reinforcement (4) includes an inner edge member longitudinal reinforcement (41), a middle edge member longitudinal reinforcement (42), and an outer edge member longitudinal reinforcement (43). The inner edge member longitudinal reinforcement (41) is located in the area enclosed by the bent section (33), the straight section (34) after bending, and the horizontal section (32) of the opening narrowing stirrup (3). The outer edge member longitudinal reinforcement (43) is located at the angle between its horizontal section (32) and the longitudinal section (31). The middle edge member longitudinal reinforcement (42) is located inside the horizontal section (32) and abuts against the horizontal section (32). The outer edge member longitudinal reinforcement (43), the middle edge member longitudinal reinforcement (42), and the opening narrowing stirrup (3) are tied and fixed at their contact points. The inner edge member longitudinal reinforcement (41) is tightened and fixed by the hook of the opening narrowing stirrup (3).
5. The bidirectional hollow slab composite shear wall with narrowed opening and stirrup connection according to claim 4, characterized in that: The number of longitudinal ribs (42) on each side of the bidirectional vacuum slab (1) is two. A first horizontal tie bar (5) is set corresponding to the longitudinal ribs (42) of the middle edge component. The first horizontal tie bar (5) corresponds one-to-one with the opening narrowing stirrup (3). The longitudinal ribs (42) of the middle edge component are tied and fixed to the first horizontal tie bar (5) inside the opening narrowing stirrup (3).
6. The bidirectional hollow slab composite shear wall with narrowed opening and stirrup connection according to claim 4, characterized in that: Multiple sets of concrete ribs (12) are arranged in the horizontal and vertical directions between the two opposite first concrete slabs (11-1) and second concrete slabs (11-2) of the bidirectional vacuum slab (1). Vertical holes are formed between the concrete ribs (12) in the horizontal direction, and horizontal holes are formed between the concrete ribs (12) in the vertical direction. One end of the bent section (33) of the opening narrowing stirrup (3) extends into the horizontal hole at the end of the bidirectional vacuum slab (1). The longitudinal reinforcement (41) of the inner edge member is arranged in the first vertical hole (16) at both ends of the bidirectional vacuum slab (1). The longitudinal section (31) of the opening narrowing stirrup (3), the longitudinal reinforcement (42) of the middle edge member, and the longitudinal reinforcement (43) of the outer edge member are all arranged on the outer side of both ends of the bidirectional vacuum slab (1).
7. The bidirectional hollow slab composite shear wall with narrowed opening and stirrup connection according to claim 6, characterized in that: The number of horizontal holes is ≥7. Among the 2-3 horizontal holes from top to bottom and the 2-3 horizontal holes from bottom to top, two sets of opening narrowing stirrups (3) are respectively set on each side of the horizontal direction of each horizontal hole. For the remaining horizontal holes, one set of opening narrowing stirrups (3) is respectively set on each side of the horizontal direction.
8. The bidirectional hollow slab composite shear wall with narrowed opening and stirrup connection according to claim 6 or 7, characterized in that: The number of vertical holes is ≥3, including two outermost first vertical holes (16) and at least one second vertical hole (15) between the two first vertical holes (16). The first vertical hole (16) is provided with an inner edge member longitudinal bar (41) in the vertical direction. Each second vertical hole (15) is provided with two wall distribution longitudinal bars in the vertical direction. The second horizontal tie bar (51) connects the two opposite wall distribution longitudinal bars inside the second vertical hole (15). The wall distribution longitudinal bars inside the second vertical hole (15) are tied and fixed at the contact point with the second horizontal tie bar (51). Tie bars (13) are embedded inside the concrete rib (12), and horizontal steel bars (14) are correspondingly set in the first concrete slab (11-1) and the second concrete slab (11-2). The tie bars (13) are integrally connected with the horizontal steel bars (14), and the horizontal steel bars (14) are embedded inside the first concrete slab (11-1) and the second concrete slab (11-2).
9. The bidirectional hollow slab composite shear wall with narrowed opening and stirrup connection according to any one of claims 1-3, characterized in that: The bidirectional vacuum plate (1) is provided with wire mesh in the two opposite first concrete slab (11-1) and second concrete slab (11-2), and the wire mesh is embedded in the first concrete slab (11-1) and the second concrete slab (11-2).
10. The bidirectional hollow slab composite shear wall with narrowed opening and stirrup connection according to any one of claims 1-3, characterized in that: Longitudinal bars and rectangular closed stirrups (6) are additionally provided in the out-of-plane direction of the longitudinal bars (4) of the edge members. The longitudinal bars (43) of the outer edge members and the longitudinal bars (42) of the middle edge members are limited at the two corners of the rectangular closed stirrups (6), and the additional longitudinal bars limit the other two corners of the rectangular closed stirrups (6).