Construction method of a reinforcing system for existing building outer frame load-bearing column

Abstract

The application discloses a construction method for reinforcing system of outer frame bearing column of existing building, which comprises the following steps: drilling holes on the periphery of the outer frame bearing column of the existing building, lowering a steel reinforcement cage into the holes and pouring concrete to form a cast-in-place pile; after the cast-in-place pile is formed, excavating the earth around the cast-in-place pile so that the upper part of the cast-in-place pile is exposed on the construction surface; breaking the exposed part of the cast-in-place pile so that the steel reinforcement cage of the cast-in-place pile is exposed; pouring a concrete cushion, cleaning and roughening the contact surface of the pile cap and the outer frame bearing column; binding the steel reinforcement of the foundation beam and the pile cap so that the foundation beam, the pile cap and the outer frame bearing column are connected into one body; supporting the formwork of the foundation beam and the pile cap and pouring the foundation beam and the pile cap with concrete; excavating the earth again so that the bottom of the outer frame bearing column is exposed; cleaning the surface of the cast-in-place pile, installing a steel sleeve on the outer periphery and cross-welding support members on the steel sleeves of adjacent cast-in-place piles.

Description

Technical Field

[0001] This invention belongs to the field of building engineering technology and relates to a construction method for a reinforcement system of load-bearing columns in the external frame of existing buildings. Background Technology

[0002] With the development of urbanization in my country, the demand for underground space development and utilization is increasing. Developing underground space while preserving and protecting existing buildings is an effective way to improve building functions and seek urban development. More and more projects are emerging that develop underground space under existing shallow foundation buildings.

[0003] In old building renovation projects, when developing and utilizing the underground space of existing old buildings, it is necessary to add a basement at the bottom of the building. Since the foundations of old buildings are usually independent foundations and frame structures, how to reinforce the existing buildings becomes a problem faced by the construction unit. Therefore, there is an urgent need to design a construction method for the reinforcement system of load-bearing columns of existing building exterior frames to solve the technical problems existing in the current technology. Summary of the Invention

[0004] The purpose of this invention is to at least partially solve some of the technical problems existing in the prior art, and to provide a construction method for a reinforcement system of load-bearing columns of the outer frame of existing buildings. The method has a reasonable structure and is easy to construct. It modifies the original independent foundation load-bearing system into a pile foundation load-bearing system and sets horizontal shear tie bars between adjacent load-bearing columns of the outer frame, thereby improving the load-bearing capacity of the existing building, reducing or avoiding deformation of the existing building during underground construction, and effectively ensuring the safety of construction.

[0005] To solve the above-mentioned technical problems, the present invention provides a construction method for a reinforcement system of load-bearing columns in the external frame of existing buildings, comprising: Step 1: Drill holes around the load-bearing columns of the existing building's outer frame, place a steel cage into the holes, and pour concrete to form cast-in-place piles. Step 2: After the cast-in-place pile is formed, excavate the soil around the cast-in-place pile so that the upper part of the cast-in-place pile is exposed on the construction surface. Step 3: Remove the exposed portion of the cast-in-place pile to expose the reinforcing cage. Step 4: Pour the concrete foundation and clean and roughen the contact surfaces between the load-bearing columns of the outer frame and the foundation. Step 5: Tie the reinforcing bars of the foundation beam and the pile cap to connect the foundation beam, the pile cap and the load-bearing columns of the outer frame into one unit; Step 6: Erect the formwork for the foundation beam and pile cap, and pour concrete to connect the foundation beam and pile cap to the cast-in-place piles. Step 7: Secondary excavation of the earthwork to expose the bottom of the load-bearing columns of the outer frame; Step 8: Clean the surface of the cast-in-place pile and install steel sleeves on the outer periphery. Cross-weld the support components to the steel sleeves of adjacent cast-in-place piles.

[0006] In some embodiments, the steel sleeves are arranged in pairs at the upper and lower parts of the cast-in-place piles, and a support is provided between the steel sleeves of adjacent cast-in-place piles; one end of the support is connected to the upper steel sleeve, and the other end is connected to the lower steel sleeve.

[0007] In some embodiments, the support member is an angle steel or channel steel, which is welded to the steel sleeve.

[0008] In some embodiments, a first tie rod is provided between adjacent support members, a first spring is provided on the outer periphery of the first tie rod, and the first spring is provided between adjacent support members.

[0009] In some embodiments, adjacent outer frame load-bearing columns are fixed together by a horizontal scissor tie, and the horizontal scissor tie is provided at the bottom of the outer frame load-bearing column.

[0010] In some embodiments, the following steps need to be performed before the cast-in-place piles are poured: S11, geological exploration and pile design; S12, level the surrounding site; S13, locate the hole position of the cast-in-place pile, then position the drilling rig and begin initial drilling; S14. Install the casing inside the pile hole, and then use a drilling rig to drill to the design elevation.

[0011] In step two, the height of the upper part of the cast-in-place pile exposed above the construction surface is greater than or equal to 800-1500mm.

[0012] In some embodiments, the height of the foundation beam is 50%-70% of the height of the upper part of the cast-in-place pile exposed above the construction surface.

[0013] In some embodiments, the horizontal scissor tie includes a connecting plate and a steel frame, wherein the connecting plate is fixed to the load-bearing column of the outer frame by expansion bolts, and the steel frame is disposed between the connecting plates.

[0014] In some embodiments, the number of steel frames is a pair, which are spaced apart in the vertical direction, and the horizontal projections of the steel frames intersect each other.

[0015] Beneficial effects of this invention: This invention provides a construction method for reinforcing load-bearing columns of existing building exterior frames. This method has a reasonable structure, is convenient to construct, and has the following advantages: a. The original independent foundation load-bearing system was modified into a pile foundation load-bearing system, which improved the load-bearing capacity of the existing building, reduced or avoided deformation of the existing building during underground construction, and effectively ensured the safety of construction. b. A first tie rod is provided between adjacent support members, and a first spring is provided on the outer periphery of the first tie rod. The first spring is located between adjacent support members to ensure the reliability of the pile foundation's load-bearing system. c. Horizontal scissor bracing is installed between adjacent external frame load-bearing columns to improve the load-bearing capacity of the existing building. Attached Figure Description

[0016] The advantages of the present invention will become clearer and more readily understood through the following detailed description in conjunction with the accompanying drawings, which are merely illustrative and do not limit the invention, wherein: Figure 1 This is a flowchart of a construction method for a reinforcement system for load-bearing columns of the external frame of an existing building, as described in this invention. Figure 2 This is a top view of the existing building external frame load-bearing column reinforcement system described in the invention; Figure 3 yes Figure 2 The corresponding sectional view of AA; Figure 4 yes Figure 2 The corresponding sectional view of BB; Figure 5 This is a schematic diagram of a horizontal scissor tie between adjacent outer frame load-bearing columns provided in an embodiment of the present invention; Figure 6 yes Figure 5 A schematic diagram of the connection between the connecting plate and the steel frame provided in the embodiment; Figure 7 yes Figure 6 The component breakdown diagram of the application components; Figure 8 This is a schematic diagram of a connecting plate provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of a steel frame provided in an embodiment of the present invention.

[0017] In the attached diagram, the components represented by each number are as follows: 10. External frame load-bearing column; 20. Cast-in-place pile; 30. Pile cap; 40. Foundation beam; 50. Steel sleeve; 60. Support component; 71. First tie rod; 72. First spring; 80. Horizontal scissor tie; 81. Connecting plate; 81a. Boss; 82. Steel frame; 82a. Steel frame main body; 82b. Steel frame connecting platform; 83. Second tie rod; 84. Second spring. Detailed Implementation

[0018] Figures 1 to 9 This is a schematic diagram of a construction method for a reinforcement system of load-bearing columns of the external frame of an existing building, as described in this application. The invention will be described in detail below with reference to specific embodiments and accompanying drawings.

[0019] The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the invention, and are illustrative and exemplary, and should not be construed as limiting the implementation or scope of the invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0020] The accompanying drawings in this specification are schematic diagrams to aid in illustrating the concept of the invention, and schematically show the shapes of the various parts and their interrelationships. Please note that, in order to clearly demonstrate the structure of the components in the embodiments of the invention, the drawings are not drawn to the same scale. The same reference numerals are used to indicate the same parts.

[0021] The flowchart of a construction method for a reinforcement system of load-bearing columns in the external frame of existing buildings, as described in this invention, is as follows: Figure 1 As shown. Construction methods for reinforcing load-bearing columns in the external frame of existing buildings include: Step 1: Drill holes around the load-bearing columns 10 of the existing building's outer frame, place a steel cage in the drilled holes and pour concrete to form cast-in-place piles 20. Figure 2 In the embodiment shown, four pile holes need to be processed around the outer frame load-bearing column 10, and the pile holes are evenly distributed with reference to the outer frame load-bearing column 10.

[0022] In some embodiments, the following steps need to be performed before the cast-in-place pile 20 is poured: S11, geological exploration, 20-ton cast-in-place pile design; S12, level the surrounding site; S13, the 20th hole of the cast-in-place pile is positioned. Then, the drilling rig is positioned and initial drilling begins. S14, install casing inside the 20 holes of the cast-in-place pile, and then use a drilling rig to drill to the design elevation.

[0023] Step 2: After the cast-in-place pile 20 is formed, the soil around the cast-in-place pile 20 is excavated so that the upper part of the cast-in-place pile 20 is exposed on the construction surface. In step two, the upper part of the cast-in-place pile 20 protruding above the construction surface is greater than or equal to 800-1500mm. Preferably, the upper part of the cast-in-place pile 20 protruding above the construction surface is 1000-1200mm to ensure that the cast-in-place pile 20 and the foundation beam 40 mentioned below have sufficient contact area, thereby achieving a reliable connection between the cast-in-place pile 20 and the foundation beam 40.

[0024] Step 3: Remove the exposed portion of the cast-in-place pile 20 to expose the reinforcing cage of the cast-in-place pile 20. Step 4: Pour the concrete foundation layer and clean and roughen the contact surface between the foundation 30 and the outer frame load-bearing column 10. Step 5: Tie the reinforcing bars of the foundation beam 40 and the pile cap 30 to connect the foundation beam 40, the pile cap 30 and the outer frame load-bearing column 10 into one unit; Step 6: Erect the formwork for the foundation beam 40 and the pile cap 30, and pour concrete for the foundation beam 40 and the pile cap 30. In some embodiments, the height of the foundation beam 40 is 50%-70% of the height of the upper part of the cast-in-place pile 20 exposed above the construction surface. This, to a certain extent, can ensure the contact area between the cast-in-place pile 2 and the foundation beam 40, ensure the stability of their connection, form a pile foundation load-bearing system, ensure the stability of the existing building's load-bearing capacity, reduce or avoid deformation of the existing building during underground construction, and thus ensure the safety of construction.

[0025] Step 7: Secondary excavation of earthwork to expose the bottom of the outer frame load-bearing column 10; Step 8: Clean the surface of the cast-in-place pile 20 and install the steel sleeve 50 on the outer periphery. Cross-weld the support 60 to the steel sleeve 50 of the adjacent cast-in-place pile 20.

[0026] In one embodiment of the present invention, the steel sleeves 50 are arranged in pairs at the upper and lower parts of the cast-in-place piles 20, and a support member 60 is provided between the steel sleeves 50 corresponding to adjacent cast-in-place piles 20, such as... Figure 2 and Figure 4 As shown; one end of the support member 60 is connected to the upper steel sleeve 50, and the other end is connected to the lower steel sleeve 50.

[0027] Specifically, the steel sleeve 50 is made of rolled steel plate and connected by bolts to form an integral ring structure.

[0028] Furthermore, in some embodiments, the support member 60 is an angle steel or channel steel, which is welded to the steel sleeve 50. It should be noted that the support member 60 can also be other profiles, which can be fixed to the steel sleeve 50 by bolts.

[0029] Figure 2In the middle, a first tie rod 71 is provided between adjacent support members 60, a first spring 72 is provided on the outer periphery of the first tie rod 71, and the first spring 72 is provided between adjacent support members 60.

[0030] In this invention, adjacent outer frame load-bearing columns 10 are fixed together by a horizontal scissor tie, and the horizontal scissor tie 80 is provided at the bottom of the outer frame load-bearing column 10.

[0031] In some embodiments, the horizontal scissor tie 80 includes a connecting plate 81 and a steel frame 82, such as Figure 5 As shown, the connecting plate 81 is fixed to the outer frame load-bearing column 10 by expansion bolts, and the steel frame 82 is arranged between the connecting plates 81.

[0032] In some embodiments, the number of steel frames 82 is a pair, which are spaced apart in the vertical direction, and the horizontal projections of the steel frames 82 intersect each other.

[0033] Figure 6 and Figure 7 In the embodiment shown, a second tie rod 83 is provided between the upper and lower steel frames 82; in order to ensure the structural strength of the horizontal scissor tie 80, a second spring 84 is provided on the outer periphery of the second tie rod 83, and the end of the second spring 84 presses against the opposite surface of the steel frame 82.

[0034] Figure 8 This is a schematic diagram of a connecting plate 81 provided in an embodiment of the present invention. A boss 81a is provided on the side of the connecting plate 81. The steel frame 82 is a structural steel and is fixed to the boss 81a, thereby being reliably connected to the side of the connecting plate 81.

[0035] Furthermore, the steel frame 82 includes a steel frame body 82a and a steel frame connecting platform 82b, such as Figure 9 As shown, the steel frame connecting platform 82b is located at the end of the steel frame body 82a. To achieve cross-connection of the steel frames 82, the steel frame connecting platform 82b is inclined relative to the axis of the steel frame body 82a, so that the steel frame connecting platforms 82b located at both ends of the steel frame body 82a are horizontally staggered. The steel frame connecting platform 82b of the steel frame 82 is connected to the boss 81a of the connecting plate 81.

[0036] In this invention, the bosses 81a are arranged in pairs and are located on the side of the connecting plate 81 to ensure interchangeability of installation and improve the convenience of operation.

[0037] As an embodiment of the present invention, the steel frame connecting platform 82b can be hinged to the end of the steel frame body 82a, so that the side of the steel frame connecting platform 82b can abut against and be fixed to the protrusion 81a of the connecting plate 81. This arrangement is beneficial to improving the construction efficiency of the horizontal scissor tie 80, realizing the reinforcement of existing buildings, and weakening or avoiding the impact of underground space construction on existing buildings.

[0038] Compared with the shortcomings and deficiencies of existing technologies, the present invention provides a construction method for a reinforcement system of load-bearing columns of the outer frame of existing buildings. Its structure is reasonable and construction is convenient. It modifies the original independent foundation load-bearing system into a pile foundation load-bearing system and sets horizontal shear tie bars between adjacent load-bearing columns of the outer frame, thereby improving the load-bearing capacity of the existing building, reducing or avoiding deformation of the existing building during underground construction, and effectively ensuring the safety of construction.

[0039] This invention is not limited to the above-described embodiments. Anyone can derive other products in various forms under the guidance of this invention. However, regardless of any changes in shape or structure, any technical solution that is the same as or similar to this application falls within the protection scope of this invention.

Claims

1. A construction method for a reinforcement system of load-bearing columns in the external frame of existing buildings, characterized in that, include: Step 1: Drill holes around the load-bearing columns of the existing building's outer frame, place a steel cage into the holes, and pour concrete to form cast-in-place piles. Step 2: After the cast-in-place pile is formed, excavate the soil around the cast-in-place pile so that the upper part of the cast-in-place pile is exposed on the construction surface. Step 3: Remove the exposed portion of the cast-in-place pile to expose the reinforcing cage. Step 4: Pour the concrete foundation and clean and roughen the contact surfaces between the load-bearing columns of the outer frame and the foundation. Step 5: Tie the reinforcing bars of the foundation beam and the pile cap to connect the foundation beam, the pile cap and the load-bearing columns of the outer frame into one unit; Step 6: Erect the formwork for the foundation beam and pile cap, and pour concrete to connect the foundation beam and pile cap to the cast-in-place piles. Step 7: Secondary excavation of the earthwork to expose the bottom of the load-bearing columns of the outer frame; Step 8: Clean the surface of the cast-in-place pile and install steel sleeves on the outer periphery. Cross-weld the support components to the steel sleeves of adjacent cast-in-place piles. The steel sleeves are installed in pairs at the upper and lower parts of the cast-in-place piles, and a support is provided between the corresponding steel sleeves of adjacent cast-in-place piles; one end of the support is connected to the upper steel sleeve, and the other end is connected to the lower steel sleeve; a first tie rod is provided between adjacent support members, and a first spring is provided on the outer periphery of the first tie rod, and the first spring is provided between adjacent support members; adjacent outer frame load-bearing columns are fixed by a horizontal scissor tie, and the horizontal scissor tie is provided at the bottom of the outer frame load-bearing column.

2. The construction method for the reinforcement system of load-bearing columns of the external frame of existing buildings according to claim 1, characterized in that, The support member is an angle steel or channel steel, which is welded to the steel sleeve.

3. The construction method for the reinforcement system of load-bearing columns of the external frame of existing buildings according to claim 1, characterized in that, Before pouring the cast-in-place piles, the following steps need to be performed: S11, geological exploration and pile design; S12, level the surrounding site; S13, locate the hole position of the cast-in-place pile, then position the drilling rig and begin initial drilling; S14. Install the casing inside the pile hole, and then use a drilling rig to drill to the design elevation.

4. The construction method for the reinforcement system of load-bearing columns of the external frame of existing buildings according to claim 1, characterized in that, In step two, the height of the upper part of the cast-in-place pile exposed above the construction surface is greater than or equal to 800-1500mm.

5. The construction method for the reinforcement system of load-bearing columns of the external frame of existing buildings according to claim 4, characterized in that, The height of the foundation beam is 50%-70% of the height of the upper part of the cast-in-place pile exposed above the construction surface.

6. The construction method for the reinforcement system of load-bearing columns of the external frame of existing buildings according to claim 1, characterized in that, The horizontal scissor tie includes a connecting plate and a steel frame. The connecting plate is fixed to the load-bearing column of the outer frame by expansion bolts, and the steel frame is arranged between the connecting plates.

7. The construction method for the reinforcement system of load-bearing columns of the external frame of existing buildings according to claim 6, characterized in that, The steel frames are in pairs, spaced apart vertically, and their horizontal projections intersect each other.

Images