Column foot connecting structure for additionally building steel structure on top plate of existing basement
By setting up reinforced concrete short columns and steel bar frames at the beam and column nodes of the existing basement roof panel, combined with shear keys and anchor bolts, the problem of reliable connection between the steel columns and the existing structure is solved, the torque is effectively transmitted, and damage to the existing structure is reduced.
Patent Information
- Application Number
- CN202421551382.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-03
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-07-03
AI Technical Summary
When adding steel structures to the roof of the reinforced concrete structure of existing basement, how to achieve a reliable connection between the steel columns and the reinforced concrete structure, minimize damage to the existing structure and ensure torque transmission.
A new reinforced concrete short column is set up at the beam and column nodes of the existing basement roof panel. Through a combination of longitudinal reinforcement, peripheral closed stirrups, tied stirrups and short stretching ribs, a reinforced skeleton is formed and connected to the existing structure, combining shear bonds and ground anchor bolts to achieve rigid connection.
Reliable connection between steel columns and existing structures is achieved, damage to existing structures is reduced, and effective transmission of vertical force, horizontal force and bending moment is ensured, which is in line with the assumption of structural stress calculation.
Smart Images
Figure CN223075209U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of reconstruction and addition of existing buildings, in particular to a column foot connection structure for adding a steel structure on the top plate of an existing basement. Background Technique
[0002] With the continuous development of social economy and urbanization construction, the use functions of some existing buildings no longer match the current use needs of the owners. To avoid large-scale demolition and reconstruction, save land resources, reduce resource consumption, and achieve green and low-carbon sustainable development, reconstructing and adding to existing buildings has become an effective and low-cost way to expand building functions and adjust building use spaces.
[0003] Advantages of steel structures: (1) High strength, light weight, good plasticity and toughness, and good seismic performance; (2) Uniform material, conforming to mechanical assumptions, with high safety and reliability; (3) Factory production, high industrialization level, fast construction speed, less environmental pollution, and recyclable materials. Steel structure components and systems are widely used in the current reconstruction and addition of existing buildings.
[0004] Compared with ordinary new construction projects, reconstruction and addition projects need to focus on the connection design and construction between the new and old structures. It is necessary to not only ensure the bearing capacity of the existing building structure after addition, but also achieve a stable connection between the new structure and the existing structure on the premise of minimizing damage to the existing structure. Whether the connection design between the new and old structures is reasonable is the key to whether the overall structure has good bearing capacity and seismic capacity after reconstruction and addition.
[0005] When adding a steel structure building on the top plate of the reinforced concrete structure of an existing basement, there are many difficulties in its reconstruction design and construction process: how to achieve a reliable connection between the steel column and the existing reinforced concrete structure, how to ensure the effective transfer of vertical force, horizontal force, and moment of the added steel structure while minimizing damage to the existing reinforced concrete structure components and minimizing the reconstruction and reinforcement of the existing reinforced concrete structure components are issues that engineers need to fully consider. Summary of the Invention
[0006] A column foot connection structure for adding a steel structure on the top plate of an existing basement provided by the utility model can effectively achieve a reliable connection between the steel column and the existing reinforced concrete structure; and while minimizing damage to the existing reinforced concrete components and minimizing the reconstruction and reinforcement of the existing reinforced concrete structure components, it ensures the effective transfer of vertical force, horizontal force, and moment of the added steel structure.
[0007] This method for designing the column base connection of adding a steel structure on the reinforced concrete structure roof slab of an existing basement has clear force analysis, strictly follows the concepts and theories of current relevant technical specifications, and has good operability. The column base connection practice has the characteristics of simple structure, clear force transmission, and convenient construction. Therefore, the present invention has the value of popularization and application.
[0008] The technical solution of the present invention is as follows:
[0009] A column base connection structure for adding a steel structure on the roof slab of an existing basement. At the beam-column joint of the roof slab of the existing basement, a new reinforced concrete short column is set. The column base of the steel column of the upper added steel structure is rigidly connected to the top surface of the new reinforced concrete short column. The lower part of the new reinforced concrete short column is embedded and connected to the existing columns and existing beams of the existing basement roof slab. The concrete of the interfering part between the existing basement roof slab and the new reinforced concrete short column is chiseled off, and the original steel bars of the existing basement roof slab are reserved. The column height and column cross-sectional dimensions of the new reinforced concrete short column are comprehensively determined according to factors such as site conditions and the steel column section stiffness of the upper added steel structure.
[0010] It can realize the setting of the steel bars of the new reinforced concrete short column and the overall pouring of the concrete, achieving the effect of the new reinforced concrete short column working together with the original structure.
[0011] A steel bar framework is arranged inside the new reinforced concrete short column. The steel bar framework includes longitudinal steel bars, peripheral closed stirrups, tie stirrups, and short tie bars.
[0012] The longitudinal steel bars include longitudinal construction steel bars and longitudinal stressed steel bars. The longitudinal construction steel bars are shown as hollow dot bars; Figure 1 The longitudinal construction steel bars within the range of the shown A-A section are set to meet the requirements of the longitudinal steel bar spacing of the new reinforced concrete short column. The lower ends of the longitudinal construction steel bars are implanted into the top surface of the existing beam; Figure 1 The longitudinal construction steel bars within the range of the shown C-C section are set to meet the requirements of the longitudinal steel bar spacing of the new reinforced concrete short column. The upper ends of the longitudinal construction steel bars are implanted into the bottom surface of the existing beam. The longitudinal stressed steel bars are shown as solid dot bars. The longitudinal stressed steel bars are bent in pairs below the bottom of the existing beam and then connected by single-sided welding; the welding length is 10 times the diameter of the steel bar, and the connection principle is shown by the virtual arc line in the C-C section drawing.
[0013] Through holes are opened on the existing beam. Each circle of peripheral closed stirrups within the height range of the existing beam is divided into 4 sections, and each section passes through the through hole and is connected by single-sided welding to form a closed hoop, and the welding length is 10 times the diameter of the steel bar. Each limb of the tie stirrups within the height range of the existing beam is divided into two sections. After the long section passes through the through hole, the end is welded to the short section, and the welding length is 10 times the diameter of the steel bar. The parts where the steel bars pass through the through holes should be filled and anchored with structural reinforcement adhesives.
[0014] When the plane formed by the longitudinal steel bars and the original longitudinal steel bars of the existing column is parallel to the tie stirrups, short tie bars are set to be bent and welded to the original longitudinal steel bars on one side, and the welding length is 10 times the diameter of the steel bar; if not parallel, the short tie bars are anchored into the existing column by post-inserted bars.
[0015] The concrete pouring construction of the newly added reinforced concrete short column shall be carried out after the interface between the new and old concretes has been treated.
[0016] A shear key is provided at the bottom surface of the steel column of the upper added steel structure, and the shear key is embedded into the shear key groove reserved on the top surface of the newly added reinforced concrete short column.
[0017] The steel column base plate of the upper added steel structure is anchored to the top surface of the newly added reinforced concrete short column through anchor bolts embedded in the newly added reinforced concrete short column, and concrete secondary grouting layer is poured into the reserved gap between the steel column base plate and the top surface of the newly added reinforced concrete short column and the reserved shear key groove, so that the steel column and the newly added reinforced concrete short column form a rigid connection.
[0018] The construction method of the present utility model includes the following steps:
[0019] A. First, chisel the original basement top slab along the outer contour of the newly added reinforced concrete short column, and retain the original top slab steel bars; before chiseling the original partial reinforced concrete slab, the load should be unloaded first and reliable supports should be made for the beam and slab. The concrete pouring construction of the newly added short column can be carried out after the interface between the new and old concretes has been treated;
[0020] B. Set up the bottom formwork, and then arrange, bind and weld the steel bars, and embed the anchor bolts: fix the longitudinal structural steel bars, longitudinal stressed steel bars, peripheral closed stirrups, tie stirrups and short tie bars, and position the embedded anchor bolts;
[0021] C. Install and fix the side formwork, and carry out concrete pouring to obtain the newly added reinforced concrete short column;
[0022] D. After the concrete solidifies, install the steel column on the top of the newly added short column, fix the bottom of the steel column to the embedded anchor bolts, and complete the concrete secondary grouting layer.
[0023] Advantages of the utility model
[0024] 1. The column foot connection structure for adding a steel structure on the existing basement top slab provided by the present utility model can effectively realize the reliable connection between the steel column and the existing reinforced concrete structure by reconstructing and designing a newly added section of reinforced concrete short column, and solves the problems of poor stability of the connection interface between the new and old reinforced concrete structures and discontinuous stress transfer at the new and old interfaces. The column foot connection structure is stable.
[0025] 2. The connection method of this patent can ensure that the vertical force, horizontal force, and bending moment of the added steel structure are effectively transmitted to the existing basement structure through the newly added reinforced concrete short columns while minimizing the damage to the existing reinforced concrete components and the transformation of the existing reinforced concrete structure; the proposed stress method of the connection node conforms to the structural stress calculation assumptions. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 It is a schematic structural diagram of the connection node of the present utility model;
[0027] Figure 2 It is a schematic diagram of removing the existing basement top slab;
[0028] Figure 3 It is Figure 1 sectional view A-A in
[0029] Figure 4 It is Figure 1 sectional view B-B in
[0030] Figure 5 It is Figure 1 sectional view C-C in
[0031] Figure 6 It is a schematic diagram of the practice of short tie bars; (the plane formed by the longitudinal steel bars and the original longitudinal bars of the existing column is parallel to the tie stirrups)
[0032] Figure 7 It is a schematic diagram of the practice of short tie bars; (the plane formed by the longitudinal steel bars and the original longitudinal bars of the existing column is not parallel to the tie stirrups)
[0033] Figure 8 It is a schematic structural diagram of the connection between the steel column base and the newly added reinforced concrete short column;
[0034] The names corresponding to the numbers in the figure are: 1. steel column; 2. existing basement top slab; 3. newly added reinforced concrete short column; 4. anchor bolts; 5. existing column; 6. existing beam; 7. longitudinal structural steel bars; 8. peripheral closed stirrups; 9. tie stirrups; 10. longitudinal stressed steel bars; 11. short tie bars; 12. original longitudinal bars; 13. welded joints; 14. shear keys; 15. secondary concrete grouting layer. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0035] Example 1
[0036] A column base connection structure for adding a steel structure on an existing basement top slab is applicable to the connection between the steel column base of a steel structure corridor added on an existing basement top slab and the concrete structure of the basement top slab.
[0037] A new reinforced concrete short column 3 is set at the beam-column node of the existing basement top plate 2. The column foot of the steel column 1 of the additional steel structure on the upper part is rigidly connected to the top surface of the new reinforced concrete short column 3. The lower part of the new reinforced concrete short column 3 is embedded and connected with the existing column 5 and the existing beam 6 of the existing basement top plate 2. The concrete is chiseled out of the interference part between the existing basement top plate 2 and the new reinforced concrete short column 3, and the original steel bars of the existing basement top plate 2 are retained. The column height and column section size of the new reinforced concrete short column are determined comprehensively according to the site conditions and the section stiffness of the steel column 1 of the additional steel structure on the upper part.
[0038] A reinforcement skeleton is arranged inside the newly added reinforced concrete short column 3, and the reinforcement skeleton includes longitudinal reinforcements, peripheral closed stirrups 8, tie stirrups 9, and short tie bars 11.
[0039] The longitudinal reinforcement includes longitudinal structural reinforcement 7 and longitudinal force-bearing reinforcement 10. The longitudinal structural reinforcement 7 is shown as a hollow point reinforcement; Figure 1 The longitudinal structural steel bars 7 within the AA section are provided to meet the longitudinal steel bar spacing requirements of the newly added reinforced concrete short column 3, and the lower end of the longitudinal structural steel bars 7 is planted in the top surface of the existing beam 6; Figure 1 The longitudinal structural steel bars 7 within the CC section are provided to meet the spacing requirements of the longitudinal steel bars of the newly added reinforced concrete short column 3. The upper end of the longitudinal structural steel bars 7 is planted in the bottom surface of the existing beam 6. The longitudinal stress-bearing steel bars 10 are shown as solid point bars. The longitudinal stress-bearing steel bars 10 are bent in pairs below the bottom of the existing beam 6 and then welded on one side. The welding length is 10 times the diameter of the steel bar. The connection principle is shown in the dotted arc in the CC section.
[0040] A through hole is provided on the existing beam 6. The closed stirrups 8 of each ring within the height range of the existing beam 6 are divided into 4 sections, and each section is welded to form a closed hoop after passing through the through hole, and the welding length is 10 times the diameter of the steel bar. The tie stirrups 9 of each limb within the height range of the existing beam 6 are divided into two sections. After the long section passes through the through hole, the end is welded to the short section, and the welding length is 10 times the diameter of the steel bar. The through hole position of the steel bar should be anchored by pouring structural reinforcement adhesive.
[0041] When the plane formed by the longitudinal steel bars and the original column longitudinal bars 12 of the existing column 5 is parallel to the tie stirrups 9, short tie bars 11 are bent and single-sidedly welded to the original column longitudinal bars 12, and the welding length is 10 times the diameter of the steel bar; if they are not parallel, the short tie bars 11 are embedded and anchored into the existing column 5.
[0042] The concrete pouring construction of the newly added reinforced concrete short column 3 should be carried out after the interface between the new and old concrete has been treated.
[0043] A shear key 14 is arranged on the bottom surface of the steel column 1 of the additional steel structure at the upper part, and the shear key 14 is embedded in the shear key groove reserved on the top surface of the newly added reinforced concrete short column 3.
[0044] The base plate of the steel column 1 of the upper additional steel structure is anchored to the top surface of the newly added reinforced concrete short column 3 through the anchor bolts 4 embedded in the newly added reinforced concrete short column 3, and the concrete secondary grouting layer 15 is poured into the reserved gap and the reserved shear key groove between the base plate of the steel column 1 and the top surface of the newly added reinforced concrete short column 3, so that the steel column 1 and the newly added reinforced concrete short column 3 form a rigid connection.
Claims
1. A column foot connection structure for adding a steel structure on the existing basement roof, characterized in that, A newly added reinforced concrete short column (3) is arranged at the beam-column node of the existing basement top plate (2); the column foot of the steel column (1) of the additional steel structure on the upper part is rigidly connected to the top surface of the newly added reinforced concrete short column (3); the lower part of the newly added reinforced concrete short column (3) is embedded and connected to the existing column (5) and the existing beam (6) of the existing basement top plate (2); the concrete is chiseled out of the interference part between the existing basement top plate (2) and the newly added reinforced concrete short column (3), and the original steel bars of the existing basement top plate (2) are retained.
2. The column base connection structure for adding a steel structure on the existing basement roof according to claim 1, characterized in that, A reinforcement skeleton is arranged inside the newly added reinforced concrete short column (3), and the reinforcement skeleton comprises longitudinal reinforcements, peripheral closed stirrups (8), tie stirrups (9), and short tie bars (11).
3. The column base connection structure for adding a steel structure on the existing basement top slab according to claim 1, characterized in that, The existing beam (6) is provided with a through hole, and each circle of the closed stirrups (8) within the height range of the existing beam (6) is divided into four sections, and each section is welded on one side to form a closed hoop after passing through the through hole, and the welding length is 10 times the diameter of the steel bar; each leg tie stirrup (9) within the height range of the existing beam (6) is divided into two sections, and after the long section passes through the through hole, the end portion is welded to the short section, and the welding length is 10 times the diameter of the steel bar; the position where the steel bar passes through the through hole is anchored by pouring a structural reinforcement adhesive.
4. The column base connection structure for adding a steel structure on the existing basement roof according to claim 2, characterized in that, When the plane formed by the longitudinal steel bars and the original column longitudinal bars (12) of the existing column (5) is parallel to the tie stirrups (9), a short tie bar (11) is bent and single-sidedly welded to the original column longitudinal bars (12), and the welding length is 10 times the diameter of the steel bar; if not parallel, the short tie bar (11) is embedded and anchored in the existing column (5).
5. The column base connection structure for adding a steel structure on the existing basement roof according to claim 1, characterized in that, A shear key (14) is arranged on the bottom surface of the steel column (1) of the additional steel structure at the top, and the shear key (14) is embedded in a shear key groove reserved on the top surface of the newly added reinforced concrete short column (3).
6. The column base connection structure for adding a steel structure on the existing basement roof according to claim 1, characterized in that, The bottom plate of the steel column (1) of the additional steel structure is anchored to the top surface of the newly added reinforced concrete short column (3) by means of anchor bolts (4) pre-buried in the newly added reinforced concrete short column (3), and a secondary concrete pouring layer (15) is poured in the reserved gap between the bottom plate of the steel column (1) and the top surface of the newly added reinforced concrete short column (3) and in the reserved shear key groove, so that the steel column (1) and the newly added reinforced concrete short column (3) are rigidly connected.