CN115853116B - Reinforced concrete frame structure reinforced by externally-attached self-resetting member and construction method - Google Patents

Abstract

The invention discloses an externally-attached self-resetting member reinforced concrete frame structure and a construction method, which belong to the technical field of building earthquake-resistant reinforcing structures, and comprise frame columns and frame beams, and further comprise: the prefabricated assembled column, the prefabricated assembled beam, unbonded prestressed tendons, energy-dissipating steel bars, connecting anchor bolts and beam end steel sleeves are arranged on the frame column, the beam end steel sleeves are embedded at two ends of the prefabricated assembled beam, the energy-dissipating steel bars penetrate through the prefabricated assembled column, the beam end steel sleeves and the outer side walls of the prefabricated assembled column are fixed at two ends, the prefabricated assembled beam and the frame beam are arranged in parallel, and two ends of the unbonded prestressed tendons penetrate through the prefabricated assembled column to be anchored on the side walls of the prefabricated assembled column. The externally-attached self-resetting member reinforcing reinforced concrete frame structure can effectively improve interlayer lateral rigidity, anti-seismic bearing capacity and lateral deformation restoring capacity of the frame structure, is simple and convenient to construct, has small influence on the structure, and can improve the anti-seismic toughness of the existing frame structure.

Description

A reinforced concrete frame structure reinforced with external self-resetting components and construction method

Technical Field

The invention belongs to the technical field of earthquake-resistant reinforcement structures of buildings, and in particular relates to a reinforced concrete frame structure reinforced by an externally attached self-resetting component and a construction method.

Background Art

At present, with the improvement of people's living standards, the safety requirements for housing construction are getting higher and higher. In addition to meeting the basic requirements of the code of "no damage in small earthquakes, repairable in medium earthquakes, and no collapse in large earthquakes", the seismic fortification of housing buildings should also have good seismic toughness, be able to reduce damage in earthquakes, and be able to quickly restore its use function after an earthquake. Therefore, improving the seismic toughness of buildings will be one of the most important development directions for current and future construction development. For a large number of existing buildings, due to the influence of the imperfect seismic fortification concept when they were built, the seismic toughness of most buildings is poor. The mechanism and method of improving the seismic toughness of existing buildings is an important topic in the current field of engineering seismic resistance.

Reinforced concrete frame structures account for a large proportion of existing buildings in my country. The seismic performance of some frame structures does not meet the basic requirements of seismic fortification, and they are prone to collapse or serious damage under strong earthquakes, resulting in casualties. Although other frame structures can meet the three-level requirements of seismic fortification, they also have the problem of insufficient seismic toughness. Under the action of a given level of earthquake, they can achieve "no collapse in a major earthquake", but they are unable to maintain and quickly restore the building's use function.

Traditional seismic reinforcement technologies for reinforced concrete frame structures mainly include direct component reinforcement technology and overall structural seismic reinforcement technology. Direct component reinforcement refers to a reinforcement method that directly improves the bearing capacity or stiffness of components by increasing the cross-section of the original structural components, wrapping steel, pasting carbon fiber, steel plates, etc., while overall structural seismic reinforcement refers to a reinforcement method that adds seismic walls, supports and other lateral force-resistant components inside and outside the structure to reduce the stress on the original structure. Buildings reinforced with these traditional methods mainly dissipate seismic energy through the development of cracks and plastic deformation of the buildings themselves. Although they can achieve "no collapse in a major earthquake", buildings generally experience large deformations that are difficult to recover in an earthquake, are severely damaged, and have poor post-earthquake repairability, resulting in poor seismic toughness. Therefore, research on seismic toughness improvement technology for existing reinforced concrete frame structures is an issue that urgently needs to be addressed.

Summary of the invention

In view of this, the present invention provides a reinforced concrete frame structure reinforced with an external self-resetting component and a construction method, the technical problem to be solved is that the current traditional seismic reinforcement technology of existing reinforced concrete structures mainly dissipates earthquake energy by causing cracks, damage and plastic deformation in the building structure itself. Under the action of an earthquake, the building generally will have large deformations that are difficult to recover, serious damage, poor post-earthquake repairability, poor seismic toughness and other problems.

In order to achieve the above object, the present invention adopts the following technical solution:

A reinforced concrete frame structure reinforced with an external self-resetting component comprises a frame column and a frame beam, and further comprises: a prefabricated assembled column, a prefabricated assembled beam, unbonded prestressed tendons, energy-absorbing steel bars, connecting anchor bolts and beam end steel sleeves, wherein a plurality of connecting anchor bolts install the prefabricated assembled column on the frame column, the beam end steel sleeves are pre-buried at both ends of the prefabricated assembled beam, the energy-absorbing steel bars pass through the prefabricated assembled column, and the two ends respectively fix the beam end steel sleeves and the outer side walls of the prefabricated assembled column, and the two ends of a plurality of prefabricated assembled beams are fixedly installed between the prefabricated assembled columns through the energy-absorbing steel bars, and are arranged parallel to the frame beam, the unbonded prestressed tendons are located inside the prefabricated assembled beams, and the two ends pass through the prefabricated assembled columns and are anchored on the side walls of the prefabricated assembled columns.

Furthermore, a first gap is provided between the prefabricated assembled column and the prefabricated assembled beam, and the first gap is used for pouring high-strength non-shrinkage grouting material.

Furthermore, a second gap is provided between the prefabricated assembled column and the frame column, and the second gap is used for pouring high-strength non-shrinkage grouting material.

A construction method for reinforcing a reinforced concrete frame structure with an externally attached self-resetting component comprises the following steps:

S1. Processing and manufacturing prefabricated assembled columns, prefabricated assembled beams and beam end steel sleeves, and pre-embedding the beam end steel sleeves at both ends of the prefabricated assembled beams;

S2. Measure and lay out on the frame column, drill holes to plant the connecting anchor bolts, insert the connecting anchor bolts into the anchor bolt holes reserved in the prefabricated assembled columns, tighten the anchor bolts, support the formwork at the second gap position and inject grout;

S3, using a hoist to hoist the prefabricated assembled beam between the corresponding prefabricated assembled columns, and inserting energy-absorbing steel bars at both ends of the prefabricated assembled beam into the prefabricated assembled columns and beam end steel sleeves;

S4. After the unbonded prestressed tendons pass through the prefabricated assembled columns and prefabricated assembled beams, anchor the two ends of the unbonded prestressed tendons on the outer side walls of the prefabricated assembled columns with prestressed anchors, support the formwork at the first gap position and perform grouting;

S5. After prestressing the unbonded prestressed tendons, high-strength grouting materials are used to seal the prestressed anchors, and finally the beam and column surfaces are painted and restored.

The beneficial effects of the present invention are:

The present invention fixes the prefabricated assembled columns on the frame columns by connecting anchor bolts, and connects the two ends of the prefabricated assembled beams with the installation of the prefabricated assembled columns by energy-consuming steel bars. The two ends of the unbonded prestressed tendons are anchored on both sides of the prefabricated assembled columns by prestressed anchors to perform prestressing tensioning, which can effectively improve the interlayer lateral stiffness and seismic bearing capacity of the frame structure. Through the performance-based reinforcement design method, the reinforced structure can be designed to maintain elasticity under the fortified earthquake and suffer slight damage under rare earthquakes, thereby improving the seismic toughness of the structure; the prestressed steel strands are designed to be in an elastic tension working state under rare and extremely rare earthquakes, thereby providing the structure with lateral deformation recovery ability, and significantly improving the seismic toughness of the existing reinforced concrete frame structure; the present invention has little impact on the original building, and the increase in the deadweight of the structure is also small. The reinforcement basically does not cause a reduction in the building's usable area, the construction site has low noise and dust, and the construction is green and environmentally friendly.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

FIG. 1 is a schematic elevation view of a reinforced concrete frame structure reinforced with an external self-resetting member.

FIG. 2 is a horizontal cross-sectional schematic diagram of FIG. 1 .

FIG. 3 is a schematic side sectional view of FIG. 1 .

Among them, in the figure:

1—frame column, 2—frame beam, 3—floor slab, 4—prefabricated column, 5—prefabricated beam, 6—unbonded prestressed tendons, 7—energy-absorbing steel bars, 8—connecting anchor bolts, 9—beam end steel sleeves, 10—second gap, 11—prestressed anchor, 12—first gap.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

As shown in Figures 1 to 3, the frame structure includes frame columns 1 and frame columns 2, and an external self-resetting component is used to reinforce the reinforced concrete frame structure. On the outer facade of the reinforced frame structure, prefabricated assembled beams 5 and prefabricated assembled columns 4 are used to reinforce the frame structure.

The prefabricated assembled column 4 is connected to the original frame column 1 in a rigid connection manner, which is equivalent to increasing the cross-section of the original frame column 1, thereby improving the lateral stiffness and bearing capacity of the frame column 1, and helping to control the lateral deformation of the structure under the design earthquake or rare earthquake in the performance-based seismic reinforcement design, reduce damage, thereby improving post-earthquake repairability, and thus improving the seismic toughness of the existing frame structure.

The prefabricated assembled beam 5 is not connected to the original frame beam 2. Under the action of an earthquake, the original frame beam 2 will not limit the deformation of the prefabricated assembled beam 5. The prefabricated assembled beam 5 is connected to the prefabricated assembled column 4 through unbonded prestressed tendons 6 and energy-absorbing steel bars 7. Under the action of an earthquake, the end face of the prefabricated assembled beam 5 and the side face of the prefabricated assembled column 4 form an opening and closing energy-absorbing mechanism. The unbonded prestressed tendons 6 enable the structure to achieve a self-resetting effect, and the energy-absorbing steel bars 7 improve the energy-absorbing capacity.

The purpose of "maintaining elasticity" of the unbonded prestressed tendons 6 is to ensure that the building has the ability to reset itself after a major earthquake, just like a rubber band that can pull the building back. The means to achieve "maintaining elasticity" is to calculate the tensile force that the unbonded prestressed tendons 6 will bear under rare and extremely rare earthquakes under the action of a given fortification intensity earthquake during structural design. If the stress converted from the tensile force exceeds its yield strength, the stress value is adjusted to be less than the yield strength by adjusting the cross-sectional area of the tie rod, so that it remains in an elastic state and there is no plastic residual strain when unloading.

As shown in Figures 1 to 3, an external prefabricated assembled beam 5 and a prefabricated assembled column 4 are used to reinforce the reinforced concrete frame structure. The prefabricated assembled column 4 and the prefabricated assembled column 5 are processed and manufactured in a prefabricated component factory. A hole for the non-bonded prestressed tendons 6 to pass through should be reserved in the prefabricated assembled column 5. A beam end steel sleeve 9 is embedded at the end of the prefabricated assembled beam 5. A hole and an anchoring pressure-bearing device for installing the non-bonded prestressed tendons 6 and the energy-absorbing steel bars 7 are embedded in the prefabricated assembled column 4. At the same time, a hole for the connecting anchor bolt 8 to pass through is embedded. The foundation of the prefabricated assembled column 4 is fixed on site. Excavate the site, pour the concrete cushion layer, implant the new and old foundation connecting steel bars, make and tie the new foundation steel bars, and cast the column foundation; measure and lay out on the frame column 1, determine the position of the connecting anchor bolt 8, drill holes on the frame column 1 and implant the connecting anchor bolt 8, install the positioning pad, and form the second gap 10 between the prefabricated assembled column 4 and the frame column 1; after the prefabricated assembled column 4 and the prefabricated assembled beam 5 are transported to the site, the prefabricated assembled column 4 is hoisted and installed with a hoist, and it should be ensured that the connecting anchor bolt 8 can be accurately inserted into the reserved space in the prefabricated assembled column 4 Anchor holes, fasten the connecting anchor bolts 8; support the formwork for the second gap 10 between the frame column 1 and the prefabricated assembled column 4, pour the grouting material, and ensure that the second gap 10 is filled; after the grouting material in the second gap 10 has reached the design strength, use the sling to lift and install the prefabricated assembled beam 5 so that it is located between the corresponding prefabricated assembled columns 4, and ensure that the energy-absorbing steel bars 7 can be accurately inserted into the reserved holes in the prefabricated assembled columns 4 and the bolt holes of the beam end steel sleeve 9, and install the positioning pads between the ends of the prefabricated assembled beam 5 and the prefabricated assembled columns 4. A first gap 12 is formed between the two, and the energy-absorbing steel bars 7 are tightened; after all the prefabricated assembled beams 5 are installed in place, the unbonded prestressed tendons 6 are inserted through the reserved holes of the outermost prefabricated assembled columns 4 until they extend out from the other end holes, and the prestressed anchors 11 are installed; a formwork is supported for the first gap 12 between the prefabricated assembled beams 5 and the prefabricated assembled columns 4, and grouting material is poured to ensure that the first gap 12 is filled; after the grouting material in the first gap 12 is cured to reach the design strength, the unbonded prestressed tendons 6 are prestressed and anchored according to the design requirements.

The specific implementation steps of the present invention are as follows:

Step 1, in the prefabricated component factory, the prefabricated assembled columns 4 and the prefabricated assembled beams 5 are processed and manufactured according to the design drawings. The holes through which the unbonded prestressed tendons 6 pass should be pre-embedded in the prefabricated assembled beams 5, the beam end steel sleeves 9 should be pre-embedded at the ends of the prefabricated assembled beams 5, the holes and anchoring pressure-bearing devices for installing the unbonded prestressed tendons 6 and the energy-absorbing steel bars 7 should be pre-embedded in the prefabricated assembled columns 4, to ensure that the unbonded prestressed tendons 6 and the energy-absorbing steel bars 7 can pass through and be installed smoothly, and the holes through which the anchor bolts 8 pass should also be pre-embedded to ensure that the connecting anchor bolts 8 can pass through and be tightened smoothly;

Step 2: excavate the site where the prefabricated assembled column 4 foundation is to be set to the bottom elevation of the foundation, pour the concrete cushion layer, implant the new and old foundation connecting steel bars according to the design drawings, make and tie the new foundation steel bars, leave the longitudinal connecting steel bars at the bottom of the prefabricated assembled column 4, and then pour the column foundation;

Step 3: Perform base treatment on the outer surface of the frame column 1 to be connected to the prefabricated assembled column 4 to ensure that the post-cast grouting material is tightly combined with the original concrete;

Step 4: measure and lay out on the frame column 1, determine the position of the connecting anchor bolt 8, drill holes on the frame column 1 to implant the connecting anchor bolt 8, and install positioning pads to ensure the formation of a second gap 10 between the prefabricated assembled column 4 and the frame column 1;

Step 5: After the prefabricated assembled column 4 and the prefabricated assembled beam 5 are transported to the site, the prefabricated assembled column 4 is hoisted and installed with a hoist, and it should be ensured that the connecting anchor bolt 8 can be accurately inserted into the anchor bolt hole reserved in the prefabricated assembled column 4, and the connecting anchor bolt 8 is tightened;

Step 6: Support a template for the second gap 10 between the frame column 1 and the prefabricated assembled column 4, pour grouting material, and ensure that the second gap 10 is fully filled;

Step 7, after the grouting material in the second gap 10 has been cured to reach the design strength, the prefabricated assembled beam 5 is hoisted and installed with a sling so that it is located between the corresponding prefabricated assembled columns 4, and it should be ensured that the energy-absorbing steel bar 7 can be accurately inserted into the reserved channel in the prefabricated assembled column 4 and the bolt hole of the beam end steel sleeve 9, and the positioning pad between the end of the prefabricated assembled beam 5 and the prefabricated assembled column 4 is installed to ensure the formation of the first gap 12 between the two, and the energy-absorbing steel bar 7 is tightened;

Step 8: After all the prefabricated assembled beams 5 on the same floor are installed in place, the unbonded prestressed tendons 6 are inserted through the reserved holes of the outermost prefabricated assembled columns until they extend out of the other end holes, and the prestressed anchors 11 are installed;

Step 9: Support a formwork for the first gap 12 between the prefabricated assembled beam 5 and the prefabricated assembled column 4, pour grouting material, and ensure that the first gap 12 is fully filled;

Step 10, after the grouting material in the first gap 12 has reached the design strength, the unbonded prestressed tendons 6 are prestressed according to the design requirements. After the prestressing is completed, the exposed steel strands of the prestressed anchor 11 are cut off so that the length of the steel strands outside the prestressed anchor 11 does not exceed 30 mm;

Step 11, the prestressed anchor 11 is sealed with high-strength grouting material, and finally the surface of the beam and column is restored by painting.

In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims (4)

1. A reinforced concrete frame structure reinforced with an external self-resetting member, comprising a frame column and a frame beam, characterized in that it also comprises: a prefabricated assembled column, a prefabricated assembled beam, unbonded prestressed tendons, energy-absorbing steel bars, connecting anchor bolts and beam end steel sleeves, wherein a plurality of connecting anchor bolts install the prefabricated assembled column on the frame column, the beam end steel sleeves are pre-buried at both ends of the prefabricated assembled beam, the energy-absorbing steel bars pass through the prefabricated assembled column, and the two ends respectively fix the beam end steel sleeves and the outer side walls of the prefabricated assembled column, and the two ends of the plurality of prefabricated assembled beams are fixedly installed between the prefabricated assembled columns through the energy-absorbing steel bars, and are arranged parallel to the frame beam, the unbonded prestressed tendons are located inside the prefabricated assembled beams, and the two ends pass through the prefabricated assembled columns and are anchored on the side walls of the prefabricated assembled columns; The prefabricated assembled columns are connected to the original frame columns in a rigid connection mode, which improves the lateral stiffness and bearing capacity of the frame columns. This helps to control the lateral deformation of the structure under design earthquakes or rare earthquakes in the performance-based seismic reinforcement design, reduce damage, and improve post-earthquake repairability, thereby improving the seismic toughness of the existing frame structure; The prefabricated assembled beam is not connected to the original frame beam. Under the action of earthquake, the original frame beam will not limit the deformation of the prefabricated assembled beam. The prefabricated assembled beam is connected to the prefabricated assembled column through unbonded prestressed tendons and energy-absorbing steel bars. Under the action of earthquake, the end face of the prefabricated assembled beam and the side face of the prefabricated assembled column form an opening and closing energy-absorbing mechanism. The unbonded prestressed tendons enable the structure to achieve a self-resetting effect, and the energy-absorbing steel bars improve the energy-absorbing capacity. Unbonded prestressed tendons ensure that the building has the ability to reset itself after a major earthquake and can pull the building back; Insert the unbonded prestressed tendons through the reserved holes of the outermost prefabricated assembled columns until they extend out of the other end holes, and install the prestressed anchors. After the unbonded prestressed tendons are tensioned, cut off the exposed steel strands of the prestressed anchors, and seal the prestressed anchors with high-strength grouting materials. 2. According to the external self-resetting component reinforced reinforced concrete frame structure described in claim 1, it is characterized in that a first gap is set between the prefabricated assembled column and the prefabricated assembled beam, and the first gap is used for pouring high-strength non-shrinkage grouting material. 3. According to the external self-resetting component reinforced reinforced concrete frame structure of claim 1, it is characterized in that a second gap is set between the prefabricated assembled column and the frame column, and the second gap is used for pouring high-strength non-shrinkage grouting material. 4. A construction method for reinforcing a reinforced concrete frame structure with an externally attached self-resetting member, characterized in that it comprises the following steps: S1. Processing and manufacturing prefabricated assembled columns, prefabricated assembled beams and beam end steel sleeves, and pre-embedding the beam end steel sleeves at both ends of the prefabricated assembled beams; S2. Measure and lay out on the frame column, drill holes to plant the connecting anchor bolts, insert the connecting anchor bolts into the anchor bolt holes reserved in the prefabricated assembled columns, tighten the anchor bolts, support the formwork at the second gap position and inject grout; S3, using a hoist to hoist the prefabricated assembled beam between the corresponding prefabricated assembled columns, and inserting energy-absorbing steel bars at both ends of the prefabricated assembled beam into the prefabricated assembled columns and beam end steel sleeves; S4. After the unbonded prestressed tendons pass through the prefabricated assembled columns and prefabricated assembled beams, anchor the two ends of the unbonded prestressed tendons on the outer side walls of the prefabricated assembled columns with prestressed anchors, support the formwork at the first gap position and perform grouting; S5. After prestressing the unbonded prestressed tendons, high-strength grouting materials are used to seal the prestressed anchors, and finally the beam and column surfaces are painted and restored.