CN113585623A

CN113585623A - Self-resetting repairable high-performance prefabricated RC column

Info

Publication number: CN113585623A
Application number: CN202111066039.XA
Authority: CN
Inventors: 马高; 马忍; 王择文
Original assignee: Hunan University
Current assignee: Hunan University
Priority date: 2021-09-13
Filing date: 2021-09-13
Publication date: 2021-11-02

Abstract

The invention discloses a self-resetting repairable high-performance prefabricated RC column, which comprises a displacement area, wherein a transition area is arranged above the displacement area, a common concrete area is arranged above the transition area, the transition area and the displacement area are both poured by Ultra High Performance Concrete (UHPC), and the common concrete area is poured by common concrete; steel strands penetrating through the whole prefabricated RC column from top to bottom are longitudinally arranged at four corners of the prefabricated RC column; the middle part is a prestressed steel strand which penetrates through the whole prefabricated RC column from top to bottom; and common steel bars penetrating through the whole prefabricated RC column from top to bottom are longitudinally arranged in the middle of four sides of the prefabricated RC column, the common steel bars in the replacement area are replaced by energy-consuming steel bars, the common steel bars and the energy-consuming steel bars are connected by adopting threaded sleeves, and UHPC (ultra high performance concrete) material packages are poured on the periphery of the common steel bars and the energy-consuming steel bars. The RC column has low residual displacement and good self-resetting capability under the action of low-cycle repeated load, and energy-consuming reinforcing steel bars in a replacement area can be replaced after being damaged, so that the RC column can be repaired conveniently after an earthquake.

Description

Self-resetting repairable high-performance prefabricated RC column

Technical Field

The invention belongs to the technical field of seismic damage restorability, and particularly relates to a self-resetting and repairable high-performance prefabricated RC column.

Background

At present, the earthquake standard requires that the structure must meet the three-level earthquake fortification target, namely the structure needs to meet the earthquake resistant requirements of small earthquake damage resistance, medium earthquake repairable and large earthquake collapse resistance. According to the method of two-stage design, namely, through checking calculation of bearing capacity and elastic-plastic deformation, the main body structure of the building can be ensured to be generally not damaged or repaired to be continuously used when the structure is influenced by earthquake motion of local modal intensity to a certain extent; when the building is affected by earthquake motion corresponding to the basic intensity of the local area, the building can be damaged and still can be normally used after general repair; when affected by seismic motion of local rare intensity, the building can still maintain stability. Engineering practice shows that three-level seismic fortification and two-stage design are effective, and in addition, the research and application of shock absorption and shock isolation enhance the energy consumption performance of the structure and enable the structure to have the advantages of small residual displacement and the like.

However, the direct and indirect losses after an earthquake disaster are enormous. Under the background, people begin to put forward higher requirements on the overall earthquake resistance of cities, and hope that the cities have more redundancies, namely when the cities encounter earthquake action, all functions of the cities can be maintained at higher levels as much as possible, and hope that the cities have quick recovery capability, namely after the cities encounter earthquake action, all functions of the cities can be quickly recovered to pre-earthquake levels or even exceed the pre-earthquake levels, and the influence of the earthquake on the normal life of people is reduced as much as possible. Thus, innovative design of each level of materials, structures, systems, cities is required, with higher recoverability of cities being desired.

The actual application of the structure with the recoverable function in the engineering is not much. After the earthquake, the column and the structure are damaged by large residual deformation and the like because of no reasonable and feasible recoverable structure during the structure design, once the residual deformation is too large, the repair is very difficult, and the reliability of the column and the structure cannot be measured even if the column and the structure can be repaired; in addition, even if the damage is only generated in a local part after the earthquake, the whole structure can be dismantled for safety, so that serious economic loss is brought, and especially for important buildings such as industrial buildings, the dismantling and rebuilding period is long, so that the indirect loss is immeasurable. Thus, the ability to maintain good self-reset of the components and structures after seismic action, small residual displacements are of great significance for recoverable designs, and repairs at low residual displacements are only meaningful. On the basis of low residual displacement, a reasonable and quick repairing and replacing scheme is also the key point for repairing the earthquake damage. However, the innovative design and theoretical research of the recoverable functional structure are not complete at present, so that the recoverable functional structure needs to be designed practically and reliably, and the structure is expected to be popularized and applied in practical engineering.

Disclosure of Invention

In order to solve the technical problem, the invention discloses a self-resetting repairable high-performance prefabricated RC column. The RC column has the advantages of low residual displacement, good self-resetting capability and the like under the action of low-cycle repeated load, and energy-consuming steel bars in a bottom replacement area can be replaced after being damaged, so that the RC column can be repaired after an earthquake.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a self-resetting repairable high-performance prefabricated RC column comprises a bottom replacement area, wherein a transition area is arranged above the bottom replacement area, a common concrete area is arranged above the transition area, the transition area and the bottom replacement area are both poured by ultrahigh-performance concrete, and the common concrete area is poured by common concrete; steel strands penetrating through the whole prefabricated RC column from top to bottom are longitudinally arranged at four corners of the prefabricated RC column; the middle part of the prefabricated RC column is a prestressed steel strand which penetrates through the whole prefabricated RC column from top to bottom; wherein, sleeves are sleeved outside the prestressed steel strand and the steel strand of the replacement area; the prefabricated RC column is characterized in that common steel bars penetrating through the transition area and the common concrete area from top to bottom are arranged in the middle of four sides of the prefabricated RC column, the bottom of each common steel bar is in threaded connection with a first threaded sleeve, each first threaded sleeve is in threaded connection with an energy dissipation steel bar in the bottom replacement area, a buckling prevention sleeve is sleeved on the outer side of each energy dissipation steel bar, and the bottom of each energy dissipation steel bar is in threaded connection with a second threaded sleeve.

In a further improvement, a core area is formed in the middle of the replacement area and is positioned on the inner side of the energy-consuming steel bars; a gap is formed between the core area and the energy-consuming steel bar; the core area, the transition area and the common concrete area are prefabricated to form an integral component, common steel bars, steel strands and sleeves are fixed in the integral component, and the bottoms of the common steel bars are exposed out of the integral component.

In a further improvement, a column bottom steel box in the core area of the replacement area is fixed at a column base of the core area; a transition area bottom steel box is fixed at the bottom of the transition area; the sleeve is a PVC pipe.

The prefabricated RC column is further improved in that during assembly, a prestressed steel strand is installed in the integral component, then the bottom of a common steel bar is in threaded connection with a first threaded sleeve, the first threaded sleeve is in threaded connection with a replaceable energy consumption steel bar, and the energy consumption steel bar is in threaded connection with a second threaded sleeve.

The prefabricated RC column is fixed on the bottom beam, and the bottom beam is fixed with a bottom beam common steel bar in threaded connection with the second threaded sleeve and a connecting hole corresponding to the steel strand and the prestressed steel strand in advance; and after the second threaded sleeve is in threaded connection with the common steel bar of the bottom beam, the steel strand penetrates through the connecting hole to be fixed, and then the prestressed steel strand penetrates through the connecting hole to be tensioned and prestressed to be fixed.

In a further improvement, a bottom steel plate with a groove at the center is fixed on the bottom beam; the common steel bar of the bottom beam penetrates through the bottom steel plate to be connected with the second threaded sleeve; the lower surface of the bottom steel plate is welded with an anchoring steel plate anchored to the bottom beam; the anchoring steel plate is provided with a horizontal hole, and a horizontal steel bar of the bottom beam penetrates through the horizontal hole on the anchoring steel plate to be anchored.

In a further improvement, the bottom steel plate and the anchoring steel plate are fixed on the bottom beam reinforcement cage in a welding mode.

Compared with the related art, the invention has the following advantages:

the RC column has the advantages of low residual displacement, good self-resetting capability and the like through reasonable structural design. 4 steel strands penetrating through the whole RC column are longitudinally arranged at four corners of the column, a PVC pipe is sleeved on the steel strands in the displacement area to realize non-bonding, the displacement area is located in a plastic hinge area with larger stress, the stress concentration of the steel strands in the area is avoided by adopting a non-bonding technology, and the stress average stress effect of the steel strands in the area is achieved; a prestressed steel strand is longitudinally arranged at the center of the column; the middle parts of four sides of the column are longitudinally provided with 4 common steel bars penetrating through the whole RC column, wherein the common steel bars in the replacement area are replaced by energy-consuming steel bars, the common steel bars and the energy-consuming steel bars are connected by adopting threaded sleeves, the outer sides of the energy-consuming steel bars are sleeved with buckling-preventing sleeves, and UHPC materials are poured and wrapped on the peripheries of the energy-consuming steel bars. The steel strand is a material with high tensile strength, low bonding and large yield strain, the center of the column longitudinally penetrates through the whole RC column to be provided with a prestressed steel strand, and the centering recovery capability of the swing column is greatly improved; UHPC is a material with high compression resistance, high ductility and energy consumption. Therefore, the column has the advantages of low residual displacement, good self-resetting capability and the like under the action of low-cycle repeated load, the energy-consuming steel bars in the bottom replacement area can be replaced after being damaged, UHPC (ultra high performance concrete) is removed from the periphery of the replacement area, the energy-consuming steel bars which are already yielded or broken are taken down and replaced by new energy-consuming steel bars in a threaded sleeve loosening and screwing mode, and UHPC (ultra high performance concrete) material is poured on the periphery to wrap the steel bars, so that the RC column can be repaired.

Drawings

The present invention is applicable to many types of RC columns such as square columns, cylinders, polygons, etc., the accompanying drawings, which are included as part of the present application to provide a further understanding of the invention, are illustrative embodiments of the present invention and are described herein to explain the present invention without unduly limiting the invention. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:

FIG. 1 is a general schematic of the present invention;

FIG. 2 is a cross-sectional view of a general concrete zone and a transition zone;

FIG. 3 is a cross-sectional view of a displacement region;

FIG. 4 is a schematic view of a displacement zone;

FIG. 5 is a connection diagram of replaceable energy-consuming reinforcing bars in a replacement area;

FIG. 6 is a view of a transition zone bottom steel box;

FIG. 7 is a diagram of a steel box at the bottom of a column in the core region of the displacement region;

FIG. 8 is a view of a beam-column connection and anchoring component;

FIG. 9 is a diagram showing the results of OpenSees low cycle reciprocating simulation performed on a conventional RC column;

fig. 10 is a diagram showing the results of openses low cycle reciprocal simulation performed on the RC column of the present invention.

The concrete column comprises a common concrete area 1, a transition area 2, a bottom replacement area 3, a bottom beam 4, a PVC pipe 5, a bottom steel plate 6, a transition area bottom steel box 7, a first threaded sleeve 8, energy-consuming steel bars 9, a buckling-restrained sleeve 10, bottom beam common steel bars 11, column body common steel bars 12, steel strands 13, prestressed steel strands 14, stirrups 15, a replacement area core area column bottom steel box 16, an anchoring steel plate 17 and a second threaded sleeve 18.

It should be noted that the drawings and the description are not intended to limit the scope of the inventive concept in any way, but to illustrate it by a person skilled in the art with reference to specific embodiments.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The self-resetting repairable high-performance prefabricated RC column shown in the figures 1-8 comprises a bottom replacement area 3, a transition area 2 is arranged above the bottom replacement area 3, a common concrete area 1 is arranged above the transition area 2, wherein the transition area 2 and the bottom replacement area 3 are both poured by Ultra High Performance Concrete (UHPC), and the common concrete area 1 is poured by common concrete; the four corners of the prefabricated RC column are longitudinally provided with steel strands 13 penetrating through the whole prefabricated RC column from top to bottom, wherein PVC pipes 5 are sleeved outside the steel strands 13 in the replacement area 3, so that stress concentration of the steel strands in the replacement area is avoided, and the stress average stress effect of the steel strands in the area is achieved; the middle part is a prestressed steel strand 14 which penetrates through the whole prefabricated RC column from top to bottom; the middle parts of four sides of the prefabricated RC column are longitudinally provided with common steel bars 12 which penetrate through the whole prefabricated RC column from top to bottom, wherein the common steel bars 12 in the replacement area 3 are replaced by energy-consuming steel bars 9, the energy-consuming steel bars 9 are connected with the common steel bars 12 by adopting threaded sleeves 8, the energy-consuming steel bars 9 are connected with common steel bars 11 by adopting threaded sleeves 18, and anti-buckling sleeves 10 are sleeved on the outer sides of the energy-consuming steel bars 9. The core area of the replacement area 3 is prefabricated with the transition area 2 and the common concrete area 1 in advance, steel strands 13 and prestressed steel strands 14 are assembled and connected with replaceable energy-consuming steel bars 9 through a threaded sleeve 8 and a threaded sleeve 18 during assembly, and then UHPC material is poured on the periphery of the replacement area 3 for wrapping. The steel box 16 is arranged at the column foot of the core area of the replacement area 3, and the steel box 7 is arranged at the bottom of the transition area 2, so that the concrete is prevented from being locally crushed. A bottom steel plate 6 with a groove in the center is arranged on the connection interface of the column bottom and the bottom beam 4, the groove of the bottom steel plate 6 is placed in the bottom core area of the RC column to provide and enhance the anti-shearing capability of the RC column, and the vertical steel bars 11 of the bottom beam 4 penetrate through the bottom steel plate 6 and are upwards connected with the energy dissipation steel bars 9 through the threaded sleeves 18; the lower surface of the bottom steel plate 6 is welded with a steel plate 17 anchored to the bottom beam, the steel plate 17 is provided with a horizontal hole, and the horizontal steel bar of the bottom beam 4 penetrates through the hole on the anchoring steel plate 17 to be anchored; the bottom steel plate 6 and the anchoring steel plate 17 are fixed on the reinforcement cage of the bottom beam 4 in a welding mode; the prestressed steel strand 14 penetrates to the bottom of the bottom beam 4 from the top of the column, the middle of the prestressed steel strand penetrates through the steel box 16 at the bottom of the column in the core area of the replacement area, a hole is reserved in the center of the steel box 16 at the bottom of the column in the core area of the replacement area in advance, and the PVC pipe 5 is placed in the path of the prestressed steel strand 14 passing through the column and the bottom beam 4 in advance.

Comparing the results of openses low cycle reciprocating simulation of the RC column of the present invention with those of a common RC column, as shown in fig. 9 and 10, it can be seen from the simulation results that the prefabricated RC column of the present invention has small residual displacement and good self-resetting effect. The low residual displacement and good self-resetting effect accord with a recoverable idea, and are a replaceable premise.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention in any way, and any simple modification, equivalent change and modification made by those skilled in the art according to the technical spirit of the present invention without departing from the technical scope of the present invention are all within the scope of the present invention.

Claims

1. The self-resetting repairable high-performance prefabricated RC column is characterized by comprising a bottom replacement area (3), wherein a transition area (2) is arranged above the bottom replacement area (3), a common concrete area (1) is arranged above the transition area (2), the transition area (2) and the bottom replacement area (3) are both poured by ultrahigh-performance concrete, and the common concrete area (1) is poured by common concrete; steel strands (13) penetrating through the whole prefabricated RC column from top to bottom are longitudinally arranged at four corners of the prefabricated RC column; the middle part of the prefabricated RC column is a prestressed steel strand (14) which penetrates through the whole prefabricated RC column from top to bottom; wherein, sleeves are sleeved outside the prestressed steel strand (14) and the steel strand (13) of the replacement area (3); the four sides middle part of prefabricated RC post disposes by last ordinary reinforcing bar (12) that run through transition district (2) and ordinary concrete district (1) down, and ordinary reinforcing bar (12) bottom threaded connection has first threaded sleeve (8), and first threaded sleeve (8) threaded connection has energy consumption reinforcing bar (9) that are in bottom replacement district (3), energy consumption reinforcing bar (9) outside cover has buckling-restrained sleeve (10), and energy consumption reinforcing bar (9) bottom threaded connection has second threaded sleeve (18).

2. The self-resetting repairable high-performance prefabricated RC column according to claim 1, wherein a core region is formed in the middle of the displacement region (3), the core region being located inside the energy-consuming reinforcing bars (9); a gap is formed between the core area and the energy consumption steel bar (9); the core area, the transition area (2) and the common concrete area (1) are prefabricated to form an integral component, common steel bars (12), steel strands (13) and sleeves are fixed in the integral component, and the bottoms of the common steel bars (12) are exposed out of the integral component.

3. The self-resetting repairable high performance prefabricated RC column according to claim 2, wherein a replacement zone core zone bottom steel box (16) is fixed at the column foot of the core zone; a transition area bottom steel box (7) is fixed at the bottom of the transition area (2); the sleeve is a PVC pipe (5).

4. The self-resetting repairable high performance prefabricated RC column according to claim 2, wherein during the assembly of the prefabricated RC column, the prestressed steel strands (14) are installed in the integral member, then the first threaded sleeve (8) is screwed on the bottom of the common steel bar (12), the first threaded sleeve (8) is screwed on the replaceable energy dissipating steel bar (9), and the energy dissipating steel bar (9) is screwed on the second threaded sleeve (18).

5. The self-resetting repairable high-performance prefabricated RC column as claimed in claim 1, wherein the prefabricated RC column is fixed on a bottom beam (4), a bottom beam common steel bar (11) which is in threaded connection with the second threaded sleeve (18) and connecting holes which correspond to the steel strands (13) and the prestressed steel strands (14) are fixed on the bottom beam (4) in advance; after the second threaded sleeve (18) is in threaded connection with the common bottom beam steel bar (11), the steel strand (13) penetrates through the connecting hole to be fixed, and then the prestressed steel strand (14) penetrates through the connecting hole to be tensioned and prestressed to be fixed.

6. The self-resetting repairable high-performance prefabricated RC column according to claim 5, wherein a bottom steel plate (6) with a groove at the center is fixed on the bottom beam (4); the common reinforcing steel bar (11) of the bottom beam penetrates through the bottom steel plate (6) to be connected with the second threaded sleeve (18); the lower surface of the bottom steel plate (6) is welded with an anchoring steel plate (17) anchored to the bottom beam; the anchoring steel plate (17) is provided with a horizontal hole, and a horizontal steel bar of the bottom beam (4) penetrates through the horizontal hole on the anchoring steel plate (17) to be anchored.

7. The self-resetting repairable high-performance prefabricated RC column according to claim 6, wherein the bottom steel plate (6) and the anchoring steel plate (17) are fixed to the bottom beam (4) reinforcement cage by welding.