CN108978996A - One kind increased outrigger and its construction method in existing brick mix structure - Google Patents

Abstract

The invention relates to a cantilever added to an existing brick-concrete structure and a construction method, comprising a cantilevered part and a built-in part, and the cantilevered part is a cast-in-place concrete cantilever extending from the inner wall of the existing brick-concrete structure The beam is located outside the building. The built-in part is composed of joists located on both sides of the inner wall. The joists are cast-in-place concrete beams. The joists are connected with the inner wall as a whole. The walls can jointly bear the vertical pressure to balance the load borne by the overhanging part and meet the anti-overturning requirements of the cantilever. The joist and the overhanging part are equipped with longitudinal bars and stirrups. The whole length extends to the end of the overhanging part, connecting the overhanging part and the built-in part as a whole. The construction of the cantilever added in the invention is simple and easy, and can meet the anti-overturning requirements of the cantilever.

Description

A cantilever beam added to existing brick-concrete structure and its construction method

technical field

The invention relates to the technical field of civil engineering, in particular to a cantilever added to an existing brick-concrete structure and a construction method thereof.

Background technique

In the past, in the design of brick-concrete structures, cantilever beams were more common. There were no columns under the cantilever beams, and the space could be used to the maximum extent, which could better meet people’s living requirements. Such as the corridor outside the office building, the balcony of the residence, etc. The cantilever beam must meet the anti-overturning requirements, so the length of the cantilever beam embedded in the masonry and the length of the cantilever must meet the requirements. "Code for Design of Masonry Structures" BG50003-2001 stipulates that the ratio of the length of the cantilever beam embedded in the masonry to the length of the overhang should be greater than 1.2;

In recent years, the demand for building reinforcement and reconstruction has been increasing, and there has been a need to add cantilever beams to the existing brick-concrete structure, such as adding external corridors or balconies to the existing brick-concrete structure due to the limited space on the ground floor, or adding beams to the existing brick-concrete structure. There is an outermost column but it affects the functional requirements. The original column needs to be removed to increase the usable space, and the corresponding concrete beam becomes a cantilever beam after the column is removed. The difficulty in installing cantilever beams in existing brick-concrete structures lies in: in order to meet the anti-overturning requirements, the cantilever beams must be embedded in the masonry for a certain length, but the existing walls not only bear the load transmitted from the floor slab of this floor, but also bear all the walls above it. Due to the weight of the body itself and the load transmitted from the floor, in actual construction, it is impossible to chisel out the wall at the position of the cantilever beam to set the cantilever beam. Therefore, it is necessary to design an economical and feasible method of adding cantilever beams in masonry-concrete structures.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art, and provide a cantilever added to the existing brick-concrete structure, which is simple and easy to construct, and has remarkable economic and social benefits.

To achieve the above object, the present invention adopts the following technical solutions:

A cantilever beam added to an existing brick-concrete structure, including a cantilevered part and a built-in part, the cantilevered part is a cast-in-place concrete cantilever beam extending from the inner wall of the existing brick-concrete structure, and is located outside the building , the built-in part is composed of joists located on both sides of the interior wall, the joists are cast-in-place concrete beams, the joists and the interior wall are connected as a whole, and the joists on both sides and the interior wall can jointly bear The pressure acts to balance the load on the overhanging part and meet the anti-overturning requirements of the cantilever. Longitudinal bars and stirrups are arranged in the joist and the cantilevered part, and all the longitudinal bars in the joist extend to the end of the cantilevered part, connecting the cantilevered part and the built-in part as a whole.

Further, the joist is located at the level of the bottom floor of the building.

Further, the joist and the inner wall are connected as a whole through a plurality of shoulder beams, and longitudinal bars and stirrups are arranged in the shoulder beams.

Further, the distance between adjacent said shoulder beams is not greater than 1 meter, and the width of the shoulder beams is not less than the length of one brick in the brick-concrete structure.

Further, connecting steel bars passing through the wall are provided between the joists on both sides of the inner wall.

The invention also discloses a construction method for adding a cantilever to an existing brick-concrete structure, which includes the following steps:

Step 1: Drill holes on the inner wall of the building according to the spacing requirements of the shoulder beams, and arrange the longitudinal bars and stirrups of the shoulder beams in the drilled holes.

Step 2: Arrange the longitudinal bars and stirrups of the joists on both sides of the inner wall, arrange the connecting bars that pass through the inner wall and connect the joists on both sides, and all the longitudinal bars of the joists pass through the outer walls of the buildings that intersect with them, And extend to the end of the overhanging part, arrange the longitudinal bars and stirrups of the overhanging part, and the longitudinal bars in the overhanging part outside the range of the joist position are implanted in the brick wall or ring beam of the building.

Step 3: Concrete the shoulder beams, joists and overhangs.

Further, in the step 2, if the original concrete column at the end of the original concrete beam of the building is removed and turned into a cantilever beam, the cantilever part is formed by pouring widened and heightened parts on the basis of the existing concrete beam , the cross-sectional shape of the newly poured widened and heightened part is "concave".

Further, in the step 2, if the cantilever beam is an external cantilever beam of the building, it does not belong to the situation of dismantling the concrete column displacement cantilever beam at the end of the original concrete beam of the building, and the cantilever part is formed by cast-in-place, Its cross-sectional shape is rectangular.

Further, the total width of the rectangular section of the cantilever part is equal to the sum of the width of two joists and the thickness of the inner wall of the building.

Beneficial effects of the present invention:

1. In the construction of the cantilever added to the existing brick-concrete structure, only holes need to be drilled on the original wall, and the original wall does not need to be removed. The construction method is simple and easy, and the economic and social benefits are remarkable.

2. The cantilever beam added in the existing brick-concrete structure of the present invention connects the joists on both sides of the built-in part and the inner wall as a whole by setting shoulder beams and connecting steel bars, and jointly bears the vertical pressure to satisfy the cantilever beam. anti-overturning requirements.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide further understanding of the present application, and the schematic embodiments and descriptions of the present application are used to explain the present application and not to limit the present application.

Figure 1 is a schematic top view of the overall structure of Embodiment 1 of the present invention;

Fig. 2 is the schematic diagram to A in Fig. 1 of the present invention;

Fig. 3 is the B direction schematic diagram in Fig. 1 of the present invention;

Fig. 4 is the C direction schematic diagram in Fig. 1 of the present invention;

5 is a schematic top view of the overall structure of Embodiment 2 of the present invention;

Fig. 6 is the D direction schematic diagram in Fig. 5 of the present invention;

Among them, 1. Exterior wall, 2. Shoulder beam, 3. Interior wall, 4. Joist beam, 5. Overhang, 6. Longitudinal reinforcement, 7. Stirrup, 8. Ring beam, 9. Floor, 10. Connection Steel bars, 11. Existing concrete beams, 12. Original concrete columns, 13. Widened and heightened parts.

Detailed ways

It should be pointed out that the following detailed description is exemplary and intended to provide further explanation to the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terminology used here is only for describing specific implementations, and is not intended to limit the exemplary implementations according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

For the convenience of description, if the words "up", "down", "left" and "right" appear in the present invention, it only means that they are consistent with the directions of up, down, left and right in the drawings themselves, and do not limit the structure. It is for the convenience of describing the present invention and simplifying the description, but does not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

As introduced in the background technology, the cantilever beam must be buried in the masonry for a certain length, but the existing wall not only bears the load transmitted from the floor of this floor, but also bears the weight of the walls of all layers above it and the load transmitted from the floor. During construction, it is impossible to chisel out the wall at the position of the cantilever beam to set the cantilever beam. Therefore, it is necessary to design an economical and feasible method for adding cantilever beams in masonry-concrete structures. In view of the above problems, the application proposes a method for adding cantilever beams to existing masonry-concrete structures.

In Example 1 of a typical implementation of the present application, cantilever beams are added outside the exterior wall of the building, as shown in Figure 1-4, a cantilever beam added to the existing brick-concrete mechanism, including integrated The cantilevered part 5 and the built-in part, the cantilevered part is a cast-in-place concrete cantilever beam extending from the inner wall of the existing brick-concrete structure, located outside the building and perpendicular to the outer wall 1 of the building, the built-in part It consists of joists 4 located on both sides of the inner wall 3, the inner wall is perpendicular to the outer wall of the building, the joist is a cast-in-place concrete beam and is located inside the building, and the joist and the inner wall are connected as a whole , jointly bear the vertical pressure effect, the joist 4 and the overhanging part 5 are provided with longitudinal bars 6 and stirrups 7, all the longitudinal bars of the joist pass through the entire length of the outer wall and extend to the overhanging part Ends, connecting the overhang and the joist as a single unit.

The joist is arranged at the bottom elevation of the floor 9 (prefabricated floor or cast-in-place slab).

The joist and the inner wall are connected as a whole through a plurality of shoulder beams 2, and the shoulder beams are set by drilling holes on the inner wall and are located below the ring beam 8 of the building. If the building is not provided with ring beams, the shoulder beams Beams are provided below the slab. The shoulder beams are cast-in-place concrete beams, equipped with longitudinal bars and stirrups, the distance between adjacent shoulder beams is not more than 1 meter, and the width of the shoulder beams is not less than the length of one brick in the brick-concrete structure, two A connecting steel bar 10 passing through the inner wall is provided between the joists to ensure that the joists and the inner walls bear the vertical pressure together.

The length of the joist is calculated and determined according to the requirement of anti-overturning bearing capacity, and meets the requirements of the ratio of the length of the cantilever beam embedded in the masonry to the length of the cantilever specified in the "Code for Design of Masonry Structures" BG50003-2001.

The invention also discloses a construction method for adding a cantilever to an existing brick-concrete structure, which includes the following steps:

Step 1: Drill holes on the inner wall of the building according to the distance between the shoulder beams, arrange the longitudinal reinforcement and stirrup of the shoulder beam in the drilled holes, and drill the longitudinal reinforcement on the outer wall and inner wall respectively and the holes through which the connecting bars pass.

Step 2: Set up the scaffolding, arrange the longitudinal bars and stirrups of the joists on both sides of the interior wall, arrange the connecting steel bars passing through the interior walls and connecting the joists on both sides, and all the longitudinal bars of the joists pass through the intersecting buildings The outer wall extends to the end of the overhang, and the longitudinal bars and stirrups of the overhang are arranged. In the overhang, the longitudinal bars arranged outside the range of the joist position are implanted in the brick wall or ring beam of the building.

Step 3: After the longitudinal reinforcement and stirrup of the shoulder beam, joist and overhanging part are installed, the formwork is set up, and concrete is poured on the shoulder beam, joist and overhanging part, and the longitudinal reinforcement of the joist passes through and intersects with it The position of the outer wall of the building is fixed by injecting glue in the hole, and the position where the connecting steel bar passes through the inner wall is fixed by injecting glue in the hole. The concrete pouring method adopts the existing concrete pouring technology, which is not carried out here. Describe in detail.

In the step 2, the cantilevered part 5 is a newly poured concrete cantilever beam, its cross-sectional shape is a rectangle, and the width h of the rectangle is equal to the sum of the width b of the two joists and the thickness a of the inner wall, i.e. h=2b+a

In Example 2 of a typical implementation of the present application, it belongs to the case of dismantling the original concrete column 12 at the end of the original concrete beam of the building. As shown in Figure 5-6, the cantilevered part includes the The existing concrete beam 11 of the object and the widened and heightened part 13 of the new pouring, the cross-sectional shape of the widened and heightened part is "concave" type, equipped with longitudinal bars and stirrups, and all longitudinal bars of the joist The ribs are extended to the ends of the widened and heightened parts. The construction method of the widened and heightened parts is the same as that of ordinary beam reinforcement. Other structures and construction methods are the same as in Example 1.

The present invention connects the built-in part of the cantilever beam and the inner wall as a whole by setting shoulder beams and connecting steel bars, and connects the cantilever part and the joist beam by extending the longitudinal reinforcement of the joist beam to the end of the cantilever part. As a whole, the joist and the inner wall bear the vertical pressure together, balance the vertical load borne by the overhanging part, and meet the anti-overturning requirements of the cantilever beam. At the same time, the original wall does not need to be demolished during construction, which is convenient for construction and economical. and significant social benefits.

Although the specific implementation of the present invention has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims (9)

1. A cantilever added in an existing brick-concrete structure, characterized in that it comprises a cantilevered part and a built-in part, and the said cantilevered part is a cast-in-place concrete cantilever extending from the inner wall of the existing brick-concrete structure The beam is located outside the building. The built-in part is composed of joists located on both sides of the inner wall. The joists are cast-in-place concrete beams. The joists are connected with the inner wall as a whole. The walls can jointly bear the vertical pressure to balance the load on the overhanging part and meet the anti-overturning requirements of the cantilever. The joist and the overhanging part are equipped with longitudinal bars and stirrups, and all the longitudinal bars in the joist are The whole length extends to the end of the overhanging part, connecting the overhanging part and the built-in part as a whole. 2. A cantilever added to an existing masonry-concrete mechanism according to claim 1, wherein the joist is located at the elevation of the floor bottom of the building. 3. A cantilever added to an existing masonry-concrete mechanism as claimed in claim 1, characterized in that, the joist and the inner wall are connected as a whole through a plurality of shoulder beams, and the shoulder beams are provided with Longitudinal bars and stirrups. 4. A kind of cantilever added in the existing brick-concrete structure as claimed in claim 1, characterized in that, the distance between adjacent said shoulder beams is not more than 1 meter, and the width of the shoulder beams is not less than that of the brick-concrete structure One brick is long. 5. A cantilever added to an existing masonry-concrete structure as claimed in claim 1, characterized in that, connecting steel bars passing through the wall are provided between the joists on both sides of the inner wall. 6. A kind of construction method of the cantilever added in the existing brick-concrete mechanism described in any one of claims 1-5, it is characterized in that, comprises the following steps: Step 1: Drill holes on the inner wall of the building according to the spacing requirements of the shoulder beams, and arrange the longitudinal bars and stirrups of the shoulder beams in the drilled holes; Step 2: Arrange the longitudinal bars and stirrups of the joists on both sides of the inner wall, arrange the connecting bars that pass through the inner wall and connect the joists on both sides, and all the longitudinal bars of the joists pass through the outer walls of the buildings that intersect with them, And extend to the end of the overhanging part, arrange the longitudinal reinforcement and stirrup of the overhanging part, and the longitudinal reinforcement in the overhanging part outside the range of the joist position is implanted in the brick wall or ring beam of the building; Step 3: Concrete the shoulder beams, joists and overhangs. 7. The construction method as claimed in claim 6, characterized in that, in said step 2, in said step 2, if the original concrete column at the end of the original concrete beam of the demolished building becomes a cantilever beam, the suspended The pick part is formed by pouring the widened and heightened part on the existing concrete beam foundation, and the cross-sectional shape of the newly poured widened and heightened part is "concave". 8. The construction method according to claim 7, characterized in that, in said step 2, if the cantilever is an external cantilever of the building, it does not belong to the removal of the concrete column displacement cantilever at the end of the original concrete beam of the building In this case, the cantilevered part is cast-in-place, and its cross-sectional shape is rectangular. 9. The construction method according to claim 8, characterized in that, the total width of the rectangular section of the overhang is equal to the sum of the width of two joists and the thickness of the inner wall.