Self-resetting shear wall based on ECC-CFRP grid mixed reinforcing bars

Abstract

The invention discloses a self-resetting shear wall based on ECC-CFRP grid mixed reinforcement. The self-resetting shear wall comprises a foundation beam, a wall body, a wall top beam body, a mixed reinforcement system and a disc spring elastic anchoring device. The wall body is divided into an engineering cement-based composite material (ECC) plastic hinge area at the bottom and a common concrete area at the upper part in the height direction, and vertical reinforcing steel bars which are vertically and continuously communicated are arranged in the wall body; the wall body adopts a gradient grid reinforcement strategy: a whole piece of CFRP grid reinforcement is configured in a common concrete area at the upper part as an anti-crack distribution reinforcement; horizontal strip-shaped CFRP grid ribs are configured in the bottom ECC area to serve as transverse constraint ribs; according to the invention, the vertical non-adhesive CFRP bars are utilized to provide active reset force, so that residual deformation after an earthquake is obviously reduced; the ordinary steel bars in the edge components are used for yielding to dissipate earthquake energy; through the strong restraining effect of the CFRP grid ribs at the bottom and the elastic buffering and deformation compensation mechanism of the disc springs, double overload protection on key parts of the wall is achieved, and the anti-seismic toughness and economical efficiency of the structure are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of seismic engineering structural technology, specifically relating to a self-resetting shear wall based on ECC-CFRP mesh hybrid reinforcement. This invention is applicable to the core tube structures of high-rise buildings in areas with high seismic fortification intensity, as well as lifeline projects with high requirements for post-earthquake functional recovery, durability, and life-cycle economic efficiency. Background Technology

[0002] As the main lateral force resisting component of high-rise buildings, shear walls bear the crucial task of resisting wind loads and seismic forces. Traditional reinforced concrete shear walls mainly dissipate seismic energy through concrete cracking and spalling, as well as the yielding deformation of the reinforcing steel. However, this "damage-for-safety" seismic resistance mechanism has significant limitations: after a moderate to large earthquake, the structure often exhibits substantial residual deformation, leading to building tilting, which is difficult or even impossible to repair, resulting in huge economic losses.

[0003] To address the issue of residual deformation, self-centering shear wall technology has emerged. Existing technologies typically use prestressed steel strands as the core restoring reinforcement. However, steel has a relatively low elastic limit strain. Under rare earthquake conditions, when the shear wall experiences significant lateral displacement, the steel strands are prone to yielding and irreversible plastic elongation, leading to severe post-earthquake prestress loss and the structure losing its self-centering capability. Furthermore, steel strands in unbonded working environments are susceptible to corrosion, affecting the long-term durability of the structure.

[0004] In recent years, carbon fiber reinforced polymer (CFRP) composites, characterized by their lightweight, high strength, corrosion resistance, and large linear elastic strain, have been introduced into shear wall structures. Existing research primarily employs an adhesive method to directly cast CFRP bars into ordinary concrete or engineering cement-based composites (ECC). While this method utilizes the material's high strength, it suffers from the following key technical drawbacks: (1) Risk of brittle failure: In the bonded system, the CFRP reinforcement at the crack in the wall will generate severe stress concentration, which is very likely to cause brittle shear or tensile fracture before reaching the ultimate strength, resulting in instantaneous failure of the structure.

[0005] (2) Lack of active restoring force: Bonded reinforcement is a passive stress-bearing member and cannot provide active restoring force to close cracks like prestressed tendons. However, if high prestress is applied, there are problems of difficult anchoring and large losses.

[0006] (3) Local crushing problem: If high-strength prestressing tendons are simply introduced to achieve self-reset, when the wall sways, the huge axial pressure will be concentrated in a small area at the toe of the wall, which can easily lead to local crushing of the concrete, and then the prestress will be unloaded instantly, causing the system to fail.

[0007] Furthermore, CFRP materials exhibit stress relaxation under long-term loads, and ordinary concrete suffers from shrinkage and creep. Both of these factors lead to the loss of prestress over time, severely impacting the long-term service performance of the structure. Therefore, there is an urgent need to develop a new shear wall structure system that can fully utilize the high elasticity of CFRP to significantly reduce residual deformation, effectively avoid the risk of brittle fracture, and simultaneously solve the problems of toe crushing and prestress loss. Summary of the Invention

[0008] Technical Problem: To overcome the shortcomings of existing technologies, the present invention aims to provide a self-resetting shear wall based on ECC-CFRP mesh hybrid reinforcement. This invention aims to significantly reduce post-earthquake residual deformation of the shear wall while effectively solving key technical challenges such as the risk of brittle fracture of CFRP reinforcement, prestress loss, and concrete crushing at the toe, thereby improving the seismic toughness and economy of the structure.

[0009] Technical Solution: To achieve the above objectives, the present invention provides a self-resetting shear wall based on ECC-CFRP mesh hybrid reinforcement, comprising a foundation beam, a wall body, a top beam, a hybrid reinforcement system, and a disc spring elastic anchoring device. The wall body is divided along its height into a bottom ECC plastic hinge region made of engineering cement-based composite material and an upper ordinary concrete region. Vertically continuous reinforcing bars are arranged within the wall body. The wall body adopts a gradient mesh reinforcement strategy: a whole sheet of CFRP mesh reinforcement is arranged in the upper ordinary concrete region as crack-resistant distributed reinforcement; horizontal strip-shaped CFRP mesh reinforcement is arranged in the bottom ECC region as transverse restraint reinforcement. The edge member regions on both sides of the wall body adopt a hybrid reinforcement system: vertical unbonded CFRP bars are symmetrically arranged inside the edge members on both sides, and vertical reinforcing bars are symmetrically arranged around the perimeter of the wall section. A full-length isolation sleeve is fitted around the vertical unbonded CFRP bars. The bottom end of the vertical unbonded CFRP bars is anchored within the foundation beam, and the top end protrudes through the top beam and is locked above the top beam after prestressing is applied by the disc spring elastic anchoring device.

[0010] The disc spring elastic anchoring device includes a top bearing steel pad, a series of disc springs, a special anchor for CFRP reinforcement, and a sealing protective cover. The top bearing steel pad is laid on the upper surface of the wall top beam. The series of disc springs is sleeved on the outer periphery of the isolation sleeve and directly abuts against the top bearing steel pad. The special anchor for CFRP reinforcement is connected to the top of the vertical non-bonded CFRP reinforcement and presses the series of disc springs. The sealing protective cover is fastened to the top bearing steel pad and is filled with anti-corrosion grease.

[0011] The horizontal strip-shaped CFRP mesh reinforcement has a horizontally extending strip-shaped structure and is only arranged in the bottom ECC area; the strip-shaped CFRP mesh reinforcement is arranged in layers along the height of the wall; the vertical spacing of the horizontal strip-shaped CFRP mesh reinforcement gradually increases from bottom to top, and is densely arranged near the bottom joint of the wall to form a strong lateral constraint on the ECC core area of ​​the wall toe.

[0012] The entire CFRP mesh reinforcement is arranged longitudinally only in the upper ordinary concrete area; the bottom end of the entire CFRP mesh reinforcement extends to the interface between the ECC plastic hinge area and the ordinary concrete area or is anchored into the top of the ECC plastic hinge area, and the entire CFRP mesh reinforcement does not penetrate the entire ECC plastic hinge area; the entire CFRP mesh reinforcement is used to control bending cracks and shrinkage cracks in the upper ordinary concrete area.

[0013] The series disc spring assembly is composed of multiple disc springs assembled in series using a mating method. Its inner diameter is larger than the outer diameter of the isolation sleeve to form a clearance fit. The isolation sleeve serves as the inner guide shaft of the disc spring assembly, and the disc spring assembly does not bear the radial compressive force from the isolation sleeve. The axial compression deformation of the disc spring assembly is used to compensate for the prestress loss of the vertical unbonded CFRP reinforcement and to serve as an overload protection buffer when the tensile force surges under a major earthquake.

[0014] The CFRP rebar anchor has a soft metal protective sleeve inside. At the anchoring connection, the top of the isolation sleeve ends at the bottom of the CFRP rebar anchor, exposing the vertical unbonded CFRP rebar inside the isolation sleeve. The soft metal protective sleeve is directly fitted onto the surface of the exposed vertical unbonded CFRP rebar, and the clamps of the CFRP rebar anchor are held on the outside of the soft metal protective sleeve. Friction anchoring is achieved through the plastic deformation of the soft metal protective sleeve.

[0015] The gap between the vertical unbonded CFRP bar and the isolation sleeve is filled with anti-corrosion lubricating grease; the bottom end of the vertical unbonded CFRP bar adopts a bonded-mechanical composite anchoring structure; this structure includes a metal sleeve filled with a high-strength bonding medium and a bottom pressure-bearing steel pad; the metal sleeve is fixed to the bottom end of the vertical unbonded CFRP bar and supported by nuts or flanges under the bottom pressure-bearing steel pad; the concrete around the bottom pressure-bearing steel pad is equipped with locally reinforced spiral stirrups to bear the local splitting tensile stress in the anchoring zone.

[0016] The vertically continuous reinforcing bars cross the bottom joint of the wall and dissipate seismic energy through yielding hysteresis under a major earthquake; the vertically unbonded CFRP bars maintain an elastic state under a major earthquake and provide a self-restoring force to restore the wall to its original position.

[0017] The construction method of the self-resetting shear wall based on ECC-CFRP mesh hybrid reinforcement of the present invention includes: firstly, prefabricating and installing the bottom anchor component; inserting the bottom end of the vertical unbonded CFRP bar into the metal sleeve on the ground and injecting adhesive for curing; assembling the locking nut and the bottom bearing steel pad; precisely positioning and fixing the "CFRP bar-anchor end integral component" into the foundation beam reinforcement cage; and simultaneously binding spiral stirrups around the anchorage area; subsequently, performing isolation protection and mesh binding; inserting the isolation sleeve into the vertical unbonded CFRP bar from above and injecting anti-corrosion grease into it, taking care to protect... To protect the exposed vertical unbonded CFRP bars from damage, the wall reinforcement is tied, and a horizontal strip of CFRP mesh is laid at the bottom, followed by a longitudinal arrangement of the entire CFRP mesh reinforcement at the top. Then, layered pouring is carried out, first pouring the bottom ECC material, and after it has initially set, pouring the upper ordinary concrete, the top beam of the wall, and the foundation beam. Finally, the top is tensioned and locked. After the concrete reaches the design strength, a top bearing steel pad, a series disc spring assembly, and a special anchor for CFRP bars are installed at the top of the wall to apply prestress to the vertical unbonded CFRP bars, lock the anchors, and install a sealing protective cover.

[0018] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) Active self-resetting and extremely low residual deformation: This invention uses vertical unbonded CFRP bars to replace traditional steel bars or bonded reinforcing bars. By utilizing the large linear elastic strain capacity of CFRP materials, it ensures that the wall remains in the elastic working stage without yielding under the large deformation of rare earthquakes. After the earthquake, it can provide strong active restoring force to close cracks, significantly reduce the residual deformation of the structure, and achieve post-earthquake repair without or with only minor repair.

[0019] (2) Overload protection and anti-brittle fracture mechanism: The disc spring elastic anchoring device installed at the top of the wall in this invention forms a "series stiffness" effect with the vertical unbonded CFRP reinforcement. Under the action of a major earthquake, when the tensile force of the vertical unbonded CFRP reinforcement surges to near its limit, the series disc spring group provides "concession buffer displacement" through further axial compression deformation, which effectively reduces the stress peak of the reinforcement and avoids the risk of brittle fracture of the vertical unbonded CFRP reinforcement in principle.

[0020] (3) Prestress self-compensation and long-term stability: Utilizing the elastic potential energy stored in the series disc spring assembly, the system can automatically compensate for prestress loss caused by concrete shrinkage and creep and stress relaxation of CFRP material, maintaining the system's long-term self-resetting capability. At the same time, the non-bonded system, combined with the full-length isolation sleeve and anti-corrosion grease, as well as the bonded-mechanical composite anchoring structure at the bottom, completely solves the problems of metal material corrosion and anchor slippage, significantly improving durability and reliability.

[0021] (4) Performance-based gradient reinforcement and crush prevention: This invention innovatively adopts a gradient mesh reinforcement strategy of "upper longitudinal and lower horizontal". The bottom ECC region utilizes the high ductility of ECC itself combined with the strong constraint of horizontal strip-shaped CFRP mesh reinforcement to significantly improve the ultimate compressive strain in the toe region, solving the problem of easy crushing of self-resetting toe concrete; the upper ordinary concrete region uses longitudinal whole-piece CFRP mesh as crack-resistant distributed reinforcement to effectively control bending and shrinkage cracks. This on-demand allocation design achieves the optimal balance between structural performance and economic cost.

[0022] (5) Multi-line energy dissipation: The edge members adopt a hybrid reinforcement system. During an earthquake, ordinary steel bars yield preferentially to dissipate energy and suppress excessive structural displacement; vertical unbonded CFRP bars maintain elasticity to provide restoring force. The two have a clear division of labor, are decoupled and work together, taking into account both energy dissipation and restoring requirements, and improving the seismic safety of the structure. Attached Figure Description

[0023] Figure 1 This is a perspective view of the self-resetting shear wall structure described in this invention; Figure 2 This is a front view of the self-resetting shear wall described in this invention; Figure 3 This is a diagram showing the cross-sectional reinforcement of the self-resetting shear wall AA described in this invention. Figure 4 This is a detailed drawing of the reinforcement of the self-resetting shear wall described in this invention; Figure 5 The disc spring of the self-resetting shear wall disc spring elastic anchoring device of the present invention; Figure 6 This is a detailed diagram of the bottom anchorage node structure of the vertical unbonded CFRP reinforcement of the self-resetting shear wall described in this invention.

[0024] The diagram includes: 1. Vertical unbonded CFRP reinforcement; 2. CFRP reinforcement anchor; 3. Series disc spring assembly; 41. Top bearing steel pad; 42. Bottom bearing steel pad; 5. Sealing protective cover; 6. Wall top beam; 7. Isolation sleeve; 8. Whole CFRP mesh reinforcement; 9. Tie bar; 10. Horizontal reinforcement; 11. Vertical reinforcement; 12. Strip CFRP mesh reinforcement; 13. Spiral stirrup; 14. Nut; 15. Metal sleeve; 16. Foundation beam. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0026] like Figures 1 to 6 As shown, the present invention provides a self-resetting shear wall based on ECC-CFRP grid hybrid reinforcement, which mainly consists of foundation beams, wall body, wall top beam, hybrid reinforcement system and disc spring elastic anchoring device.

[0027] like Figure 1 , 2 As shown, the wall is divided into two regions along its height: the bottom ECC plastic hinge region, located at the bottom of the wall (dark gray area in the figure), typically ranging from 1 / 3 to 1 / 2 of the wall's cross-sectional height. This region is constructed using ECC, an engineering cement-based composite material with high ductility and multi-crack characteristics, utilizing its excellent ultimate tensile strain (>1%) and compressive toughness to accommodate the large deformations of the plastic hinge zone. The upper ordinary concrete region, located above the ECC region and extending to the top of the wall, is constructed using ordinary concrete.

[0028] Gradient mesh reinforcement strategy, such as Figure 2 and Figure 4 As shown, the web area of ​​the wall adopts differentiated reinforcement for different stress requirements: in the upper ordinary concrete area of ​​the web, a whole piece of CFRP mesh reinforcement 8 is arranged longitudinally, which mainly cooperates to bear the vertical tensile force and control the shrinkage and bending cracks of the upper concrete as crack-resistant distribution reinforcement; while in the bottom ECC area, only horizontal strip-shaped CFRP mesh reinforcement 12 is arranged. The strip has a horizontally extended strip structure and is arranged in layers along the height of the wall; in order to resist the highly concentrated compressive stress at the toe of the wall, the vertical arrangement spacing of the horizontal strip-shaped CFRP mesh reinforcement 12 is designed to gradually increase from bottom to top (i.e., denser arrangement near the bottom joint of the wall), and its two ends penetrate into the interior of the edge members on both sides and are effectively anchored, thereby forming a strong lateral constraint on the ECC core area and preventing the toe of the wall from being crushed.

[0029] Hybrid reinforcement system for edge members, such as Figure 3 As shown in the AA section diagram, the edge members (hidden columns) on both sides of the wall adopt a hybrid reinforcement configuration of "symmetrical reset + peripheral energy dissipation": the vertical steel bars 11 are symmetrically arranged around the perimeter of the hidden column section and are constrained by the horizontal steel bars 10 and tie bars 9. Under a major earthquake, they yield across the bottom joint of the wall and dissipate seismic energy through hysteretic deformation; while the vertical unbonded CFRP bars 1 are symmetrically arranged inside the edge members on both sides (the white large circle in the figure), and are covered with a full-length isolation sleeve 7. In this embodiment, the isolation sleeve 7 is preferably made of rigid polyvinyl chloride (PVC) pipe, the inner diameter of which is slightly larger than the diameter of the vertical unbonded CFRP bars 1 and the pipe is filled with anti-corrosion lubricating grease to ensure that the vertical unbonded CFRP bars 1 are not bonded to the concrete and can slide freely along the entire length.

[0030] Top disc spring elastic anchoring device such as Figure 5As shown, the top of the vertical unbonded CFRP bar 1 extends through the top beam 6 of the wall and connects to the disc spring device. The device, from bottom to top, includes a top bearing steel pad 41 laid on the surface of the top beam 6, and a series of disc springs 3 sleeved on the outer periphery of the isolation sleeve 7 and directly abutting the pad. The disc springs are assembled by multiple disc springs in series in a mating manner, and the isolation sleeve 7 serves as its inner guide shaft, with a clearance fit between the two. The top of the device is provided with a CFRP bar special anchor 2 for connecting the vertical unbonded CFRP bar 1 and pressing the disc springs. In order to prevent the clamping plates from crushing the vertical unbonded CFRP bar 1, a soft metal protective sleeve is provided inside the CFRP bar special anchor 2. At this time, the top of the isolation sleeve 7 ends at the bottom surface of the anchor, and the soft metal protective sleeve is directly sleeved on the exposed surface of the vertical unbonded CFRP bar 1, achieving frictional anchoring through the plastic deformation of the soft metal.

[0031] Bottom anchoring nodes such as Figure 6 As shown, the bottom end of the vertical unbonded CFRP reinforcement 1 is deeply embedded in the foundation beam 16 using a bonded-mechanical composite anchoring structure. This structure specifically includes a metal sleeve 15 (i.e., an anchoring sleeve), into which the bottom end of the vertical unbonded CFRP reinforcement 1 is inserted and bonded together with high-strength epoxy resin. A nut 14 is screwed onto the external thread at the end of the metal sleeve 15 (or a flange structure is used), and a bottom bearing steel pad 42 is provided above the nut 14 to disperse the anchoring tension. Furthermore, as a key measure to prevent anchoring failure, spiral stirrups 13 are also configured in the concrete anchoring zone above the bottom bearing steel pad 42 to restrain the core concrete and bear the enormous local splitting tensile stress, thereby ensuring that the vertical unbonded CFRP reinforcement 1 is not pulled out.

[0032] Construction method: The construction steps of this invention mainly include: First, prefabrication and installation of the bottom anchor component. The bottom end of the vertical unbonded CFRP bar 1 is inserted into the metal sleeve 15 on the ground and cured with adhesive. The locking nut 14 and the bottom bearing steel pad 42 are assembled. The "CFRP bar-anchor end integral component" is precisely positioned and fixed inside the foundation beam reinforcement cage. Simultaneously, spiral stirrups 13 are tied around the anchorage area. Then, isolation protection and mesh binding are performed. The isolation sleeve 7 is inserted from above into the vertical unbonded CFRP bar and anti-corrosion grease is injected inside. Care is taken to protect the exposed vertical unbonded CFRP bars. The RP reinforcement 1 is not damaged. Then, the wall reinforcement is tied, the bottom horizontal strip CFRP mesh reinforcement 12 is laid, and the upper longitudinal CFRP mesh reinforcement 8 is arranged. Then, the layered pouring is carried out. First, the bottom ECC material is poured. After it has initially set, the upper ordinary concrete, the top beam 6 and the foundation beam 16 are poured. Finally, the top tensioning and locking are carried out. After the concrete reaches the design strength, the top bearing steel pad 41, the series disc spring group 3 and the CFRP reinforcement special anchor 2 are installed on the top of the wall to apply prestress to the vertical unbonded CFRP reinforcement 1, lock the anchor and install the sealing protective cover 5.

[0033] Working principle: When the structure encounters an earthquake, the working mechanism of this invention is as follows: During minor earthquakes, the structure is in an elastic working state. The longitudinally arranged whole CFRP mesh 8 at the top and the horizontally arranged strip-shaped CFRP mesh strips 12 at the bottom work together to effectively control the development of micro-cracks in the wall. When encountering a major earthquake, the wall sways and rises, and the joints at the bottom of the wall open. At this time, the vertical steel bars 11 in the edge members cross the joints and yield, dissipating a large amount of seismic energy through hysteretic deformation and suppressing excessive structural displacement. At the same time, the vertical unbonded CFRP bars 1 always remain in an elastic state and are stretched as the wall rises, thereby providing active reset. During this process, a dual overload protection mechanism is activated simultaneously: the top series disc spring group 3 provides a concession buffer through further compression deformation to prevent the vertical unbonded CFRP reinforcement 1 from brittle fracture due to the surge in tensile force, while the horizontally arranged strip-shaped CFRP mesh reinforcement 12 at the bottom forms a strong lateral constraint on the ECC core area at the wall toe, effectively preventing the ECC from crushing under high pressure stress; when the seismic action stops, the elastic recoil force of the vertical unbonded CFRP reinforcement 1 and the restoring force of the series disc spring group 3 overcome the frictional resistance, pull the wall back to its initial position and close the cracks, thereby significantly reducing residual deformation and achieving rapid restoration of structural function.

Claims

1. An ECC-CFRP mesh hybrid reinforced self-centering shear wall, characterized in that: The application relates to a wall structure, which comprises a foundation beam, a wall body, a wall top beam body, a mixed reinforcement system and a disc spring elastic anchoring device; the wall body is divided into an engineering cement composite material (ECC) plastic hinge area at the bottom and an ordinary concrete area at the top along the height direction, and vertical steel bars (11) are arranged in the wall body in a vertically continuous penetrating mode; the wall body adopts a gradient grid reinforcement strategy; CFRP grid bars (8) are arranged in the ordinary concrete area at the top as anti-cracking distributed reinforcement; horizontal strip-shaped CFRP grid bars (12) are arranged in the bottom ECC area as transverse constraint bars; a mixed reinforcement system is adopted in the edge member area at both sides of the wall body; vertically non-bonded CFRP bars (1) are symmetrically arranged in the edge member area at both sides, and vertical steel bars (11) are symmetrically arranged around the wall body section; the vertically non-bonded CFRP bars (1) are externally sleeved with full-length penetrating isolation sleeves (7); the bottom end of the vertically non-bonded CFRP bars (1) is anchored in the foundation beam (15), the top end penetrates out of the wall top beam body (6), and the disc spring elastic anchoring device is used to apply prestress and lock above the wall top beam body (6).

2. The self-centering shear wall based on ECC-CFRP hybrid reinforcement according to claim 1, characterized in that: The disc spring elastic anchoring device comprises a top pressure bearing steel pad (41), a series disc spring group (3), a CFRP bar special anchor (2) and a sealing protective cover (5); the top pressure bearing steel pad (41) is laid on the upper surface of the wall top beam body (6); the series disc spring group (3) is sleeved on the outer periphery of the isolation sleeve (7) and directly bears on the top pressure bearing steel pad (41); the CFRP bar special anchor (2) is connected to the top end of the vertically non-bonded CFRP bar (1) and compresses the series disc spring group (3); the sealing protective cover (5) is buckled on the top pressure bearing steel pad (41), and the sealing protective cover is filled with anticorrosive grease.

3. The self-centering shear wall based on ECC-CFRP hybrid reinforcement according to claim 1, characterized in that: The horizontal strip-shaped CFRP grid bar (12) is arranged in a horizontal strip-shaped structure and is arranged only in the bottom ECC area; the horizontal strip-shaped CFRP grid bar (12) is arranged in layers along the height direction of the wall body; the vertical arrangement spacing of the horizontal strip-shaped CFRP grid bar (12) gradually increases from bottom to top, and the horizontal strip-shaped CFRP grid bar (12) is densely arranged near the wall bottom joint, so as to form strong transverse constraint on the ECC core area of the wall toe.

4. The self-centering shear wall based on ECC-CFRP hybrid reinforcement according to claim 1, characterized in that: The whole CFRP grid bar (8) is arranged only in the longitudinal direction in the upper ordinary concrete area; the bottom end of the whole CFRP grid bar (8) extends to the interface between the ECC plastic hinge area and the ordinary concrete area or is anchored into the top of the ECC plastic hinge area, and the whole CFRP grid bar (8) does not penetrate through the whole ECC plastic hinge area; the whole CFRP grid bar (8) is used for controlling the bending cracks and shrinkage cracks of the upper ordinary concrete area.

5. The self-centering shear wall based on ECC-CFRP hybrid reinforcement according to claim 2, wherein: The series disc spring group (3) is assembled by multiple disc springs in a way of series connection, and the inner hole diameter is larger than the outer diameter of the isolation sleeve (7) to form a gap fit; the isolation sleeve (7) is used as an inner guide shaft of the disc spring group, and the disc spring group does not bear the radial extrusion force from the isolation sleeve; the axial compression deformation of the disc spring group is used to compensate the prestress loss of the vertical unbonded CFRP tendon (1), and is used as overload protection buffer when the pulling force increases sharply under a large earthquake.

6. The self-centering shear wall based on ECC-CFRP hybrid reinforcement according to claim 2, characterized in that: The CFRP tendon special anchor (2) is internally provided with a soft metal protective sleeve; at the anchoring connection, the top end of the isolation sleeve (7) is cut off at the bottom surface of the CFRP tendon special anchor (2), so that the vertical unbonded CFRP tendon (1) in the isolation sleeve (7) is exposed; the soft metal protective sleeve is directly sleeved on the surface of the exposed vertical unbonded CFRP tendon (1), and the clamping piece of the CFRP tendon special anchor (2) is clamped outside the soft metal protective sleeve, and the plastic deformation of the soft metal protective sleeve realizes the friction anchoring.

7. The self-centering shear wall based on ECC-CFRP hybrid reinforcement according to claim 1, wherein: The gap between the vertical unbonded CFRP tendon (1) and the isolation sleeve (7) is filled with corrosion-resistant lubricating grease; the bottom end of the vertical unbonded CFRP tendon (1) adopts a bonded-mechanical composite anchoring structure; the structure includes a metal sleeve (15) filled with high-strength bonding medium and a bottom pressure steel pad (42); the metal sleeve (15) is fixed to the bottom end of the vertical unbonded CFRP tendon (1) and is supported below the bottom pressure steel pad (42) by a nut (14) or a flange; the local reinforced spiral hoop (13) is arranged in the concrete around the bottom pressure steel pad (42), and is used to bear the local splitting tensile stress of the anchoring area.

8. The self-centering shear wall based on ECC-CFRP hybrid reinforcement according to claim 1, characterized in that: The vertical continuous through vertical steel bars (11) span the wall bottom joint, and dissipate seismic energy through yield hysteresis under the action of a large earthquake; the vertical unbonded CFRP tendon (1) remains in an elastic state under the action of a large earthquake, and provides a self-resetting force for resetting the wall.

9. The construction method of the self-centering shear wall based on ECC-CFRP grid hybrid reinforcement according to claim 1, characterized in that The construction steps mainly include: firstly, precast and install the bottom anchor assembly, insert the bottom end of the vertical unbonded CFRP tendon (1) into the metal sleeve (15) on the ground and pour glue to solidify, assemble the locking nut (14) and the bottom pressure steel pad (42), accurately position and fix the "CFRP tendon-anchor end integral assembly" in the steel reinforcement cage of the foundation beam, and bind the spiral stirrup (13) around the anchoring area; then, carry out isolation protection and mesh binding, insert the isolation sleeve (7) into the vertical unbonded CFRP tendon (1) from above and inject corrosion-resistant grease inward, pay attention to protect the exposed vertical unbonded CFRP tendon (1) from being damaged, then bind the wall steel reinforcement, lay the bottom horizontal strip-shaped CFRP mesh (12) and the upper longitudinal whole CFRP mesh tendon (8); then, carry out layer-by-layer pouring, first pour the ECC material at the bottom, then pour the upper ordinary concrete, the top beam body (6) and the foundation beam (16) after the initial setting of the ECC material; finally, carry out top tension locking, after the concrete reaches the design strength, install the top pressure steel pad (41), the series disc spring group (3) and the CFRP tendon special anchor (2) on the top of the wall, apply prestress to the vertical unbonded CFRP tendon (1), lock the anchor and install the sealing protective cover (5).

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