CN111962952A - A kind of concrete-filled steel tubular column-H-shaped steel beam-steel support-π-shaped connecting piece combined middle column bottom node and method - Google Patents

Abstract

The invention discloses a concrete-filled steel tube column-H-shaped steel beam-steel support-π-shaped connecting piece combined type middle column bottom node and a method for the method. It consists of parts, web connecting plates, high-strength bolts, steel supports, I-shaped bench tie bars, slab-column tie bars, and prefabricated recycled concrete floor slabs. Compared with the prior art, the node has simple structure, convenient construction, clear force transmission path, and has two anti-seismic defense lines. The invention creatively proposes new structures such as π-shaped connectors, bench-shaped steel bars, and plate-column-tie steel bars, and the integrity of the plate-column-node domain is enhanced. Effectively improve the bending resistance, compression resistance and stability of the node. This further ensures the reliability of the connection structure between the steel support and the π-shaped node. The joint beam-column-bracing-floor connection is firm, the integrity is strong, and the seismic performance is excellent, which provides key technical support for the engineering design of the light steel composite structure of the prefabricated green house.

Description

A concrete-filled steel tubular column-H-shaped steel beam-steel support-π-shaped connecting piece combined central column Bottom nodes and practices

technical field

The invention relates to a combined middle column bottom node of a concrete filled steel tube column-H-shaped steel beam-steel support-π-shaped connector and a method thereof, and belongs to the technical field of structural engineering.

Background technique

Relying on industrialization to realize the development of housing industrialization has become an inevitable trend, and the development of housing industrialization technology is the main means to realize the widespread application of prefabricated buildings and achieve the goal of urban green building development.

The prefabricated steel structure has the advantages of light weight, high strength, high production efficiency, and high level of assembly. It is an ideal structural system for the industrialization of village houses. The prefabricated light steel residential system has high assembly efficiency, low steel consumption and low construction cost. If combined with structural components such as concrete-filled steel tubes, the steel consumption and the cross-sectional size of the components can be further reduced, and excellent bearing capacity and seismic performance can be obtained.

Traditional steel structures mostly use H-shaped steel columns as load-bearing components, but for village houses with a building length-to-width ratio close to 1, the H-shaped steel columns have poor bending performance in the weak axis direction. Moreover, when the H-section steel column exceeds a certain slenderness ratio, the column bottom has the risk of instability when it is subjected to large bending moments and axial forces. The use of CFST column as a composite member can not only meet the stress principle of the same seismic performance in the two main axis directions, but also greatly improve the bearing capacity under complex stress states due to the combined action of the steel tube and the inner-filled concrete. and improved corrosion resistance. And the column section size can be further reduced, thereby saving concrete and steel consumption. If the recycled concrete is poured inside the steel tube to form a square steel tube recycled concrete column, the purpose of sustainable green circulation is achieved, and it is more beneficial to environmental protection. Therefore, the square steel tube recycled concrete column is suitable for the prefabricated light steel residential system.

The seismic performance and assembly rate of the light steel structure system depend to a certain extent on whether the stress of the joint structure is reasonable or not and the degree of assembly. In the traditional steel structure system, the beam-column connection joints mostly adopt the outer ring plate connection, the inner partition plate connection and the cast steel connection. These connection forms are suitable for heavy-duty steel structure workshops with large spans and large loads. Its joint structure is complex, the amount of steel used is large, and the welding work on the construction site cannot be avoided. The degree of assembly is low, and it is not suitable for beam-column connection of light steel residential system. At the same time, the traditional node connection structure does not consider the assembly connection of prefabricated floor slabs and prefabricated walls. At present, most prefabricated walls are complicated to connect with traditional nodes, especially the bottom nodes at the base beam position, and the connection reliability between the prefabricated floor and the nodes at the bottom beam-column nodes is low, and structural measures such as waterproofing and moisture-proofing are difficult to achieve. Due to the existence of stiffeners and other structures at the nodes, the prefabricated wall panels need to cut out the corresponding space in advance, which is easy to cause cold bridges, which is not conducive to the insulation and energy saving of houses. In addition, the square steel tube recycled concrete column has high bearing capacity. In the light steel village and town residential structure, the column section width can be controlled at 100-150mm. The reduction of the column cross-section results in a decrease in the overall lateral stiffness of the structure. Therefore, it is necessary to improve the overall stiffness of the structure by setting interlayer supports. There are currently no beam-column connection configurations available for steel bracing assemblies.

To sum up, the design of a lightweight prefabricated concrete-filled square steel tubular column-H-beam bottom connection node, which is simple in structure, clear in force transmission, excellent in seismic performance, suitable for prefabricated wall panels and floor slabs, and conducive to the installation of prefabricated steel supports. At present, the problems to be solved urgently in the development of the light steel composite structure residential system in villages and towns. Based on this, the present invention proposes a concrete-filled steel tube column-H-shaped steel beam-steel support-π-shaped connector combined type middle column bottom node and method, which is especially suitable for low and multi-storey light steel frame structure residential bottom middle column connection The application of nodes, on the premise of ensuring the safety and reliability of the structure, improves the economy and assembly efficiency of light steel houses, and provides technical reference for the industrialization of houses and building assembly.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a concrete-filled steel tube column-H-shaped steel beam-steel support-π-shaped connecting piece combined type middle column bottom node and method, so as to solve the unreasonable stress of the beam-column connection node at the bottom of the middle column of the light steel frame residence , The steel consumption is large, and the structure is complex. Solve the problem of connecting the prefabricated floor at the bottom of the central column, the steel support and the beam-column joint.

In order to achieve the above object, the present invention adopts the following technical solutions: a concrete-filled steel tube column-H-shaped steel beam-steel support-π-shaped connector combined type middle column bottom node and method, the node structure comprises a lightweight square steel tube recycled concrete column ( 1), column-plate tie bars (2), H-shaped steel beams (3), π-shaped connectors (4), web connection plates (5), 30mm long high-strength bolts (6), floor shear bolts ( 7), the upper limb of the π-shaped connector (8), the lower limb of the π-shaped connector (9), the rectangular bottom plate (10), the prefabricated steel support (11), the 70mm through high-strength bolts (12), the I-shaped bench tie steel bar (13) ), a grouting material pallet (14), a prefabricated recycled concrete floor slab (15) and a floor slab reinforcement (16). As shown in Figures 1, 2, 3, and 4

The connection and composition of the components of the invention are as follows: the column-plate tie bars (2) are welded on the light-weight square steel tube recycled concrete column (1) for connecting the prefabricated recycled concrete floor (15); The upper limb (8) of the π-shaped connector, the lower limb (9) of the π-shaped connector, and the rectangular bottom plate (10) are composed of the rectangular bottom plate (10) being a steel plate with a rectangular hole in the middle, and the upper limb (8) of the The lower limbs (9) of the connecting piece are respectively fully welded on the rectangular base plate (10) to form a π-shaped connecting piece (4); The four sides of the outer edge of the rectangular bottom plate (10) on the connecting piece (4) are welded with the steel pipe wall of the light-duty square steel pipe to form four fillet welds on the outer edge. The light-duty square steel pipe recycled concrete column (1) is welded to the steel pipe wall to form four fillet welds on the inner edge, so the light-duty square steel pipe recycled concrete column (1) and a single π-shaped connector (4) are connected by a total of 8 fillet welds from the inside to the outside. ; The web connecting plate (5) is welded to the steel tube wall of the light-duty square steel tube recycled concrete column (1) through the inner opening of the rectangular base plate (10) through two right-angle welds; the upper and lower flanges of the H-shaped steel beam (3) are The upper limb (8) and the lower limb (9) of the π-shaped connector (4) are connected by 30mm long high-strength bolts (6); the web of the H-shaped steel beam (3) is connected to the web connection plate (5) Connect by 30mm long high-strength bolts (6); prefabricated steel supports (11) are connected to the upper limb (8) of the π-shaped connector by 30mm long high-strength bolts (6) and 70mm through high-strength bolts (12); prefabricated recycled concrete The floor slab (15) is connected with the H-shaped steel beam (3) through the slab shear studs (7) and high-strength grouting material; the prefabricated recycled concrete floor slab (15) is connected with the column-slab tie bars (2) and the I-shaped bench tie bars (13), the floor steel bars (16) are bound to each other and finally connected by high-strength pouring grouting material; the grouting material support plate (14) is embedded in the prefabricated recycled concrete floor slab (15); The high-strength bolts (12) are fixed at the web of the upper limb (8) of the π-shaped connector, and are bound with the floor reinforcement bars (16). 15) Form one.

The square steel pipe in the light-duty square steel pipe recycled concrete column (1) is a square hot-rolled seamless steel pipe. The outer diameter of the steel pipe is 100mm-150mm, the wall thickness is 4mm-8mm, the recycled concrete is filled, the particle size of the recycled coarse aggregate is 5mm-20mm, and the concrete strength is C30-C50. The light-duty square steel tube recycled concrete column (1) has the following advantages: the square steel tube has a constraining effect on the inner filled recycled concrete, which improves the bearing capacity of the recycled concrete and enhances the ductility of the concrete; the inner filled recycled concrete limits the buckling of the steel tube, which can effectively Avoid instability and damage of steel pipes. Due to the combined effect of the thin-walled steel pipe and the filled concrete, the cross-sectional size of the column can be greatly reduced compared with the concrete structure, and the amount of steel used in the column of the steel structure is further reduced. Steel pipe can be used as a formwork for concrete pouring, which is more convenient and cost-effective for construction. In practical engineering, CFST columns have the advantages of high construction rigidity, high bearing capacity, and good fire and corrosion resistance. After using recycled concrete materials, it has both environmental advantages.

The column-plate tie bars (2) are steel bars with bent anchoring ends. The diameter of the steel bar is 8mm, and the strength grade is HRB345. The length is 80mm, and the bending length of the anchor end is 40mm. It is welded on the recycled concrete column (1) of the light-weight square steel tube, and the welding position is at the same height as the steel bars in the prefabricated recycled concrete floor slab (15), and the spacing is 50mm. During assembly, the column-slab tie bars (2) and the floor steel bars (16) are bound together, and high-strength grouting material is poured in the reserved holes between the prefabricated recycled concrete floor slab (15) and the light-duty square steel tube recycled concrete column (1). Its main function is to effectively tie the light-duty square steel tube recycled concrete column (1) and the prefabricated recycled concrete floor slab (15) to enhance the integrity of the joint and improve the stiffness and energy dissipation capacity of each section.

The H-shaped steel beam (3) is the main load-bearing member in the light steel frame structure, which mainly bears the wall and floor loads and transfers them to the light-weight square steel tube recycled concrete column (1). In the light steel composite structure, the hot-rolled H-beam is generally used as the main beam or the secondary beam. In order to avoid local buckling at the end of the H-shaped steel beam (2) due to the stress concentration of the structural column connected to the node, the upper limb (8) of the π-shaped connecting piece and the lower limb (9) of the π-shaped connecting piece of the π-shaped connecting piece (4) Provide stiffeners with a thickness equal to the web thickness of the H-beam (3) to increase end stiffness. Since the upper limb (8) of the π-shaped connector and the lower limb (9) of the π-shaped connector need to be welded with the rectangular bottom plate (10), in order to prevent the upper and lower flanges of the steel beam at the welding seam from being unable to fit closely with the steel pipe column, it needs to be assembled before assembly. Grind the upper and lower ends of the H-beam (3) with 7mm triangular notches to ensure accurate alignment of the bolt holes. The shear studs are evenly arranged on the top surface of the H-shaped steel beam (3), ready to be used for the installation of the prefabricated floor.

The π-shaped connecting piece (4) is a key component of the beam-column joint of the light steel composite frame, and is composed of the upper limb (8) of the π-shaped connecting piece, the lower limb (9) of the π-shaped connecting piece and a rectangular bottom plate (10) with a central hole. .

The web connecting plate (5) is a rectangular steel plate, its length is the same as the length of the upper limb (8) of the π-shaped connecting piece and the lower limb (9) of the π-shaped connecting piece, and the width is 80% of the height of the rectangular hole in the rectangular bottom plate (10), The thickness is equal to the thickness of the web of the H-beam (3). One side of the web connecting plate (5) is vertically welded to the column wall of the light-duty square steel tube recycled concrete column (1) through two vertical fillet welds and a rectangular hole in the center of the rectangular bottom plate (9). The web connecting plate (4) is connected to the web of the H-shaped steel beam (3) through a 30mm long high-strength bolt (6) to form the second line of defense for the joint against earthquakes. The test proves that the web connecting plate (5) can still provide reliable flexural and shear bearing capacity for the joint after the π-shaped connector (4) fails under the action of earthquake, so it can effectively prevent the light steel frame from being caused by the π-shaped connector. (4) Failure of beam-column joints due to damage, resulting in continuous collapse of the structure. The width of the web connecting plate (5) is smaller than the height of the rectangular hole of the rectangular bottom plate (10), so that the inner fillet weld between the rectangular bottom plate (10) and the light-duty square steel tube recycled concrete column (1) can be avoided. The axis of the web connecting plate (5) deviates from the centerline of the web of the H-shaped steel beam (2) by 0.5 times the sum of the thickness of the web connecting plate (5) and 0.5 times the thickness of the web of the H-shaped steel beam (2). It is ensured that the center line of the web plate of the H-shaped steel beam (2) can coincide with the center of the section width of the light-duty square steel tube recycled concrete column (1). The welding seam quality control level shall be first or second.

The 30mm long high-strength bolts (6) are an important link in the connection of beam-column joints, and their materials should be high-strength alloy steel or other high-quality steel, and two strength grades of 8.8 and 10.9 are mostly used in prefabricated light steel houses. Its length is generally 10-20mm exposed outside the nut. Its main function is to connect and fasten the H-shaped steel beam (3) with the π-shaped connecting piece (4), the web connecting plate (5), and connect the prefabricated steel support (11) with the upper limb (8) of the π-shaped connecting piece. At the same time, in order to facilitate the installation of high-strength bolts at the nodes, the nuts can be welded to the bolt holes of the upper limb (8) of the π-shaped connector and the lower limb (9) of the π-shaped connector, and torque is applied between the upper and lower flanges of the H-shaped steel beam (3). A wrench assembles the bolts, setting each bolt to the same torque.

The floor shear stud (7) is an important structure to strengthen the connection between the H-shaped steel beam (3) and the prefabricated concrete slab, and can act as a floor shear key. On the one hand, the node segment is set up with two channels for reinforcement. The horizontal spacing is 80-150mm. After the prefabricated recycled concrete floor slab (15) is assembled, high-strength grouting material is poured at the reserved holes of the floor slab shear studs (7) to complete the H-shaped steel beam (3) and the prefabricated recycled concrete floor slab (15). )Connection.

The upper limb (8) of the π-shaped connecting piece and the lower limb (9) of the π-shaped connecting piece are two short I-beam beams of the same material and size, and their outreach lengths are 1.0 to 1.5 of the beam height of the H-shaped steel beam (3). The beam height is 0.5 to 1.0 times the beam height of the H-shaped steel beam (3), the thickness of the upper and lower flanges and the web is 0.8 to 1.0 times the thickness of the H-shaped steel beam (3) flange, and the flange width is the same as that of the H-shaped steel beam (3). The flange width of the steel beam (3) is the same. The upper limb (8) of the π-shaped connecting piece and the lower limb (9) of the π-shaped connecting piece are vertically welded to the rectangular bottom plate (10) through fillet welding, and the upper limb (8) and the lower limb (9) of the π-shaped connecting piece are about the center The centroid of the open rectangular bottom plate (10) is symmetrically arranged, and the centroid distance between the bottom of the lower flange of the upper I-beam cantilever short beam and the top of the upper flange of the lower I-beam cantilever short beam from the center of the rectangular bottom plate (10) with the central hole They are respectively 0.55 times the beam height of the H-shaped steel beam (3). In this way, it can be ensured that the upper limb (8) of the π-shaped connecting piece and the lower limb (9) of the π-shaped connecting piece retain a certain gap, so that the H-shaped steel beam (3) can be smoothly assembled on the upper limb (8) of the π-shaped connecting piece and the lower limb of the π-shaped connecting piece. (9). The π-shaped connector (4) is connected with the light-weight square steel tube recycled concrete column (1) through the outer fillet weld and the inner fillet weld by stick welding, and the quality control level of the weld shall be first or second.

The rectangular bottom plate (10) is a rectangular steel plate with a central hole. Its material strength is the same as the steel used for the light-weight square steel tube recycled concrete column (1), and Q345 steel can be used in light-steel residential buildings. Its height is 300mm, and it meets the size requirements of right-angle welds with the upper limb (8) of the π-shaped connecting piece and the lower limb (9) of the π-shaped connecting piece. Its width is 100mm, that is, it is the same width as the upper limb (8) of the π-shaped connecting piece and the lower limb (9) of the π-shaped connecting piece, and meets the size requirements of the outer fillet weld. The rectangular hole in the middle of the rectangular bottom plate (10) is 60 mm wide and 140 mm high, and meets the size requirements of the inner fillet weld. The rectangular base plate (10) mainly plays the role of connecting and transitioning between the light-duty square steel pipe recycled concrete column (1) and the π-shaped connecting piece (4), and the thickness of the steel pipe wall of the light-duty square steel pipe recycled concrete column (1) is partially strengthened to protect this part The wall of the steel pipe column is not corroded.

The steel support (11) is a hot-rolled H-section steel, and is generally arranged between two adjacent light-duty square steel tube recycled concrete columns (1) at an angle of 60° to 45°. The width of the flange of the steel support (11) is equal to the upper limb (8) of the π-shaped connecting piece, and the height of the web is generally 60mm to 100mm. Made of Q345 steel. The lower end is connected with the upper flange of the upper limb (8) of the π-shaped connector through a steel plate with bolt holes through a 30mm long high-strength bolt (6) and a 70mm through high-strength bolt (12). The steel support is welded to the steel plate at its lower end. The steel bracing (11) mainly serves to improve the lateral rigidity and bearing capacity of the frame and to improve the energy dissipation capacity of the frame during an earthquake.

The 70mm through high-strength bolts (12) are S8.8S or S10.3-grade high-strength bolts. The upper end is located on the upper surface of the bottom gusset plate of the prefabricated steel support (11), and the lower end is located on the lower surface of the upper flange of the H-shaped steel beam (3). 70mm through high-strength bolts (12) are connected to the bottom gusset plate of the prefabricated steel support (11), the upper limb (8) of the π-shaped connecting piece and the upper flange of the H-shaped steel beam (3). Connect the three into a whole, and at the same time, clamp one side of the I-shaped bench tie steel bar (13) to the web position of the upper limb (8) of the π-shaped connector, so as to connect the I-shaped bench tie steel bar (13) with the π-shaped tie-tie steel bar (13). The role of the connector (4).

The I-shaped bench tie reinforcement bar (13) is a prefabricated three-dimensional reinforcement cage. The I-shaped bench-tie reinforcement bar (13) is mainly composed of two parts: a transversely-tie-tie bow-shaped steel mesh and a longitudinally-tie-tie bar. The transversely knotted bow-shaped steel mesh is composed of two bow-shaped steel bars with anchor ends on both sides and the middle transverse connecting steel bar. The length of the bow-shaped steel bars on both sides is 80mm, and the length of the right-angle anchoring end is 30mm. The two transverse connecting bars in the middle are 70mm long and 60mm apart. The two ends are fixed to the bow-shaped steel bar by spot welding or binding to form a prefabricated three-dimensional steel mesh. The transversely tied bow-shaped steel mesh is arranged at the webs of the upper limbs (8) of the π-shaped connecting pieces on both sides of the column. The longitudinal tie bars are composed of two 300mm long steel bars, which are spot welded with the bow-shaped steel meshes at both ends, so that the bow-shaped steel meshes on both sides of the column are tied together. The two parts of the I-shaped bench tie steel bar (13) are made of HRB335Φ8 steel bars. The bow-shaped steel bar mesh extends into the reserved holes of the prefabricated recycled concrete floor slab (15) and is bound with the exposed floor slab steel bar (16), and the other end passes through 70mm The through high-strength bolts (12) are fixed at the position of the web of the upper limb (8) of the π-shaped connecting piece, and two I-shaped bench tie bars (13) are symmetrically arranged on both sides of the web of the upper limb (8) of the π-shaped connecting piece. Designing it in the shape of a "bench" is conducive to the anchoring between it and the floor reinforcement (16) and the grouting material, and at the same time, the anchoring end facing down can elevate the steel mesh so that it is at the same height as the floor reinforcement (16) for easy binding. The longitudinal tie bars are tied together with the floor reinforcement bars (16) and the column-slab tie bars (2) while the bow-shaped steel meshes at both ends are tied together, so that the prefabricated recycled concrete floor slabs (15) and the π-shaped connectors (4) are bound together. And the light-weight square steel tube recycled concrete column (1) forms a unified whole, which effectively improves the integrity of the node domain.

The grouting material pallet (14) is a thin steel plate welded with pre-embedded anchoring steel bar hooks on three sides, its thickness is 3mm, and the size of the rectangular steel plate is 390mm in length and 110mm in width. A grouting hole with a length of 370 mm and a width of 100 mm reserved here is slightly larger than the prefabricated recycled concrete floor slab (14). The grouting material pallet (14) is embedded in the lower part of the reserved hole before the prefabricated recycled concrete floor slab (15) is formed, and the upper surface of the steel plate is flush with the lower surface of the floor slab and the upper surface of the lower flange of the upper limb (8) of the π-shaped connector. The outer edge of the steel plate is matched with the edge of the lower flange of the upper limb (8) of the π-shaped connecting piece, so it can be ensured that the bottom of the grouting material will not leak after the grouting material is poured.

The prefabricated recycled concrete floor slab (15) is a factory-prefabricated reinforced concrete floor slab, and its thickness is 80 mm to 100 mm, which is the same height as the upper limb (8) of the π-shaped connector and the lower limb (9) of the π-shaped connector. Strength is C40. According to the design requirements, there is a single-layer or double-layer steel mesh inside. Generally, HRB335 grade Φ8 steel bars are used, and the spacing between the steel bars is 100mm. A grouting hole of 100 mm long and 100 mm wide is reserved for the upper limb (8) of the π-shaped connecting piece at the node of the prefabricated floor slab, and the surface of the floor slab is flush with the upper flange surface of the upper limb (8) of the π-shaped connecting piece. The bench steel bar (14) is placed inside the grouting hole and high-strength grouting material is poured, so that the grouting material fills the reserved hole and both sides of the web of the upper limb (7) of the π-shaped connector, so as to achieve the purpose of working together between the floor slab and the prefabricated node.

The floor reinforcement bars (16) are distributed reinforcement bars arranged in the prefabricated recycled concrete floor slab (15), and the distribution reinforcement bars exposed at the reserved holes serve to connect with the I-shaped bench tie reinforcement bars (13).

The invention relates to a concrete-filled steel tube column-H-shaped steel beam-steel support-π-shaped connecting piece combined type middle column bottom node and a method, and the specific method is as follows:

Step 1: Factory prefabricated lightweight square steel tube recycled concrete columns (1), column-plate tie bars (2), purchase square steel tubes and steel plates of corresponding sizes, cut, grind, and drill holes to weld the base connecting plate at the bottom, and then internally The recycled concrete is poured, and the production of the square steel tube recycled concrete column (1) is completed after curing. The fabricated column-slab tie bars (2) are welded to the corresponding positions on both sides of the light-duty square steel tube recycled concrete column (1) as shown in Figure 5.

Step 2: Process the π-shaped connector (4) and the web connecting plate (5) in the factory workshop, first purchase the finished hot-rolled I-beam of the corresponding size, and cut, grind, punch, etc. to make the π-shaped connection. The upper limb (8) of the piece and the lower limb (9) of the π-shaped connecting piece are cut and drilled from a hot-rolled steel plate of a corresponding thickness to make a rectangular bottom plate (10). The upper limb (8) of the π-shaped connecting piece and the lower limb (9) of the π-shaped connecting piece are welded with the rectangular bottom plate (10) to manufacture the π-shaped connecting piece (4). Purchase a steel plate of corresponding size and strength to cut and open the holes to make a web connecting plate (5). As shown in Figure 6.

The third step: welding the π-shaped connecting piece (4) and the web connecting plate (5) to the corresponding positions on both sides of the light-duty square steel tube recycled concrete column (1) in the factory workshop. First, weld the π-shaped connector (4) to the light-weight square steel tube recycled concrete column (1). It should be noted that the π-shaped connector (4) is connected to the light-weight square steel tube recycled concrete column (1) through the outer and inner fillet welds. ) side welding connection, so the π-shaped connector (4) is connected to the square steel pipe column through two rounds of rectangular full-welded fillet welds, which fully guarantees the length of the weld and fully meets the shear bearing capacity and bending resistance of the weld at the node. carrying capacity. Then, the web connecting plate (5) is welded to the square steel tube column through the central hole of the rectangular bottom plate (10). Weld the nuts to the positions of the bolt holes of the upper limb (8) of the π-shaped connector and the lower limb (9) of the π-shaped connector to prepare for installing the bolts. As shown in Figure 7.

Step 4: A stiffening rib is arranged to be welded on the H-shaped steel beam (3), and the thickness of the stiffening rib is not less than the thickness of the web of the H-shaped steel beam (3). Process the upper and lower flanges and web bolt holes of the H-beam (3) according to the design position. Finally, the studs are welded on the top surface of the H-beam (3). As shown in Figure 8.

Step 5: The factory processes the prefabricated steel support (11), purchases hot-rolled H-beams that meet the cross-sectional size requirements, and grinds and cuts them into corresponding sizes. Purchase steel plates, and process the bottom gusset plate of steel support after cutting, grinding, drilling and other processes. Weld the machined steel supports to the bottom gusset plate. Prefabricated steel supports are finished. As shown in Figure 9.

Step 6: Make the grouting material pallet (14) and the prefabricated recycled concrete floor slab (15), the factory purchased finished steel plates and cut them into corresponding sizes, and process the steel bars for anchoring on the grouting material pallet (14) through processes such as cutting and bending. Hook, spot welding the steel bar hook to the steel plate to complete the grouting material pallet. Make and bind the steel bars of the floor slab, support the floor slab formwork, place the grouting material pallet at the opening, pour the recycled concrete of the floor slab, and maintain the molding. As shown in Figure 10.

Step 7: Install the light-duty square steel tube recycled concrete column (1) with the π-shaped connector (4) and the web connecting plate (5) on the construction site, and install the steel tube concrete column to the foundation through the foundation connecting plate. Cut a triangular notch with a length of about 5mm at the upper and lower ends of the H-shaped steel beam (6), and slide the H-shaped steel beam (3) between the π-shaped connecting pieces (4) of the steel pipe columns on both sides, so that the π-shaped connecting pieces ( 4) and the bolt holes on the web connecting plate (5) are aligned with the bolt holes of the H-beam (3), and fasten them with high-strength bolts. As shown in Figure 11.

Step 8: Install the prefabricated recycled concrete floor slab into the corresponding position. As shown in Figure 12.

Step 9: Install the prefabricated steel support (11) to the corresponding position through high-strength bolts. As shown in Figure 13.

Step 10: Place the I-shaped bench tie bars (13) at the corresponding positions, and tighten the 70mm through high-strength bolts (13) to fix the I-shaped bench tie bars (13) at the web position of the upper limb (8) of the π-shaped connector . The transverse bow-shaped tie bars at both ends of the I-shaped bench tie bars (13) are bound to the floor steel bars (16). Bind the longitudinal tie bars to the column-slab tie bars (2) and the floor reinforcement bars (16). As shown in Figure 14.

The eleventh step: pour high-strength grouting material on the floor shear studs (7), the upper limbs of the π-shaped connectors (8), the I-shaped bench tie bars (13), and the grouting material pallets (14), etc. After completion, subsequent construction can be carried out. As shown in Figure 15.

Compared with the prior art, the present invention relates to a π-shaped connector mid-column bottom node and method suitable for CFST column-H-shaped steel beam-steel support connection, and has the following advantages:

1. The present invention creatively adopts the structure of the π-shaped connector (4) to assemble and connect between beams and columns: the π-shaped connector (4) increases the height of the beam-column joint domain and improves the joint shear bearing capacity. At the same time, the rectangular bottom plate (9) with the central hole is welded to the light-weight square steel tube recycled concrete column (1), so that the steel of the column wall at the node is not directly exposed to the air, and the corrosion resistance of the node is improved. The entire node has strong bending and shear bearing capacity. At the same time, the π-shaped connectors only need to be arranged on the side with the beam, and the π-shaped connectors at different positions on the same column are not continuous. If there is no direct connection between the π connectors on both sides of the central column, one node on one side fails, and the node on the other side will not be affected. The risk of successive collapse of the structure is reduced.

2. The present invention creatively assembles the node connection structure and the steel support structure: bolt holes are opened on the upper flange of the upper limb (8) of the π-shaped connector (4) and the bottom connecting plate of the prefabricated steel support (11). Connect with bolts. This form of construction enables the steel supports to be assembled at the frame assembly stage, and supports installation without the need for additional components at a later stage. It greatly simplifies construction steps, saves costs and improves construction efficiency.

3. The invention creatively realizes the integrated design of the plate-column-node domain and the node domains on both sides of the central column by using the bench tie bars and column-slab tie bars for the prefabricated floor slab: the prefabricated recycled concrete floor slab (15) is in the A hole is opened at the connection part with the upper limb (8) of the π-shaped connecting piece, and the floor steel bar (16) is exposed inside, and the floor steel bar (16) is bound with the I-shaped bench tie steel bar (13). The I-shaped bench tie steel bar (13) is fixed to the upper limb (8) of the π-shaped connecting piece through a 70mm through high-strength bolt (12). Finally, high-strength grouting material is poured at the opening, which forms the connection structure of prefabricated floor slab-bench-shaped tie-bar-π-shaped connector.

At the same time, the longitudinal steel bars of the bench-shaped tie bars are bound with the slab-column tie bars, and the floor slabs and the light-weight CFST columns are tied through the grouting material, which enhances the coordinated deformation ability of the slab-column-joint domain. At the same time, the longitudinal reinforcement structure effectively ties the upper limbs (8) of the π-shaped connectors on both sides of the central column, which improves the integrity of the node domains on both sides of the central column and improves the ductility of the slab-column-node domain to a certain extent.

At the same time, the π-shaped connector is filled with steel pipe grouting material, which greatly enhances its bending resistance, compression resistance and stability. This further ensures the reliability of the connection structure between the steel support and the π-shaped node.

4. The present invention creatively realizes the overall installation of the floor slab at the central column position. In the prefabricated traditional steel structure house, because the structure of the beam-column node area is relatively complex, it is difficult to realize the integral assembly of the floor slab in the central column beam-column node area. The slab can be split and assembled in this area, which greatly weakens the integrity of the slab and the performance of the joint and slab combination work. In this invention, since the floor slab and the π-shaped connector of the node are integrally cast, the mid-span column can be assembled on the H-shaped steel beams on both sides by reserving holes in the floor slab, and the bench-shaped tie bars and the slab-column tie bars can be used. Effectively combines the node-column-plate as a whole. The stiffness of the joint is greatly improved, and the bearing capacity of the joint is improved in a complex state. At the same time, the assembly quantity of 2 to 4 slabs at the original central column node was reduced to 1, which greatly improved the construction efficiency.

5. It is conducive to the construction of waterproof and moisture-proof houses, and it is convenient for the construction of thermal insulation and waterproof structures. In the present invention, the assembly position of the prefabricated floor slab is located 300mm above the foundation, and the bottom is separated from the foundation, which is more conducive to the waterproofing and moisture-proofing of the first floor of the house. At the same time, the π-shaped connector of the upper flange of the node is poured together with the floor slab, which facilitates the installation of the external wall and the thermal insulation structure, avoids the generation of cold bridges to a certain extent, and is conducive to thermal insulation and energy saving of the house.

6. The force is clear, with two anti-seismic defense lines. The node connection structure involved in the present invention is simple in design and high in reliability. The I-shaped section beam transfers the building load to the beam-column joint, and the axial force, shear force and bending moment of the I-shaped section beam are transmitted to the π-shaped connecting piece and the web connecting plate through the bolts, and finally the rectangular bottom plate and the web connecting plate are connected. The welding seam realizes the force transmission between the two and the steel pipe column. Therefore, the joint design under different loads can be completed by controlling the length of the weld and the thickness of the steel, and its design reliability is more clear. Under the action of seismic reciprocating load, the π-shaped connector acts as the first line of defense to dissipate most of the seismic energy. After the failure of the π-shaped connector, the web connecting plate can still bear the shear force and bending moment, and the entire node can continue to work. This has positive significance for the anti-continuous collapse and post-earthquake repair of the fabricated structure under the action of earthquake.

7. High degree of assembly and high level of industrialization. The square steel tube recycled concrete column, the π-shaped connecting piece, the web connecting plate, the H-shaped steel beam, etc. involved in the present invention can all be prefabricated in engineering and assembled on the construction site. The large-scale production of the project has high precision, strict quality control and resource saving. The workload of welding and wet work at the construction site is reduced, and standard parts with unified standards and different specifications can be produced for different beam and column sections for assembly, which is conducive to the realization of residential industrialization.

8. Energy saving and environmental protection, convenient transportation. The prefabricated connecting piece involved in the present invention consumes less steel, adopts recycled concrete and other environment-friendly and energy-saving materials, and mostly adopts hot-rolled section steel for node components, which is easy to obtain and can basically realize no waste. The node construction method proposed by the present invention places the processes that are likely to cause noise pollution and light pollution in the factory, and can achieve green environmental protection while ensuring the construction quality.

Description of drawings

Figure 1. The disassembly diagram of the node structure.

Figure 2. Overall top view of the node.

Figure 3. The overall axonometric view of the node.

Figure 4 Overall bottom view of the node.

Figure 5 Step 1 - Fabrication of recycled concrete-filled steel tubular columns.

Figure 6 Step 2 - Making the pi-connector and web connection plate.

Figure 7 Step 3 - Soldering the Pi Connector.

Figure 8 Step 4 - Making the I-Beam Bottom Beam.

Figure 9 Step 5 - Making the Steel Support.

Figure 10 Step 6 - Making Precast Recycled Concrete Floor Slabs.

Figure 11 Step 7 - Assemble the beam and column.

Figure 12 Step 8 - Assemble the floor.

Figure 13 Step 9 - Assemble the Steel Support.

Figure 14 Step 10 - Binding and fixing the bench steel bars.

Figure 15 Step 11—Pour the grout.

Detailed ways

The invention will be further described below with reference to specific embodiments.

As shown in Fig. 3, a CFST column-H-shaped steel beam-steel support-π-shaped connector combined type middle column bottom node, the node includes a light-weight square steel tube recycled concrete column (1), a column-plate tie bar ( 2), H-shaped steel beams (3), π-shaped connectors (4), web connecting plates (5), 30mm long high-strength bolts (6), floor shear studs (7), upper limbs of π-shaped connectors ( 8), the lower limb of the π-shaped connector (9), the rectangular bottom plate (10), the prefabricated steel support (11), the 70mm through high-strength bolts (12), the I-shaped bench tie bars (13), the grouting material support plate (14) , a prefabricated recycled concrete floor slab (15) and a floor slab reinforcement (16).

According to the size of the building load, the bearing capacity of the steel tube recycled concrete column can be calculated, and the steel tube recycled concrete column can be adjusted by adjusting the outer diameter, thickness and strength of the recycled concrete of the steel tube. According to the bending moment and shear force at the end of the H-shaped steel beam, the main parameters such as flange and web thickness, beam height, and cantilever length of the upper and lower flange connectors of the π-shaped connector are designed, and the length and thickness of the rectangular bottom plate are determined. Center opening size, etc. At the same time, according to the axial force, shear force and bending moment of the H-beam end, adjust the length and thickness of the web connecting plate, and calculate the number of bolts and weld length required in the node domain. The beam-column joints involved in the present invention can control the joint connection stiffness through the above-mentioned parameter design changes, so as to achieve the design goal of rigid joints or semi-rigid joints.

Design parameters such as floor thickness, concrete strength, distribution bar diameter, distribution bar spacing and other parameters according to the floor load. Determine the location and size of the reserved holes according to the size of the π-shaped connector and the arrangement of the shear bolts on the beam.

According to the relevant theory of structural seismic design, parameters such as section size and arrangement angle of prefabricated steel bracing are determined. After the above data is determined, the process of blanking, production, construction and assembly can be carried out.

According to the section width of the recycled concrete column of the light steel tube and the size of the opening of the prefabricated floor, the plate-column tie-bar and the bench-shaped tie-bar are designed.

In the normal use stage, the π-shaped connector increases the height of the beam-column joint domain, so the joint of the present invention has greater stiffness in the elastic working stage, effectively controlling the deformation of the I-shaped section beam, and in the normal use state It avoids the defects of excessive beam deflection and excessive beam vibration amplitude excited by external vibration loads.

At the same time, the floor slab and the π-shaped connector in this node are effectively connected through bench-shaped and high-strength bolts and other structures, and the π-shaped connector is strengthened after the grouting is poured in the later stage. Because the upper limb of the π-shaped connector is connected with both the bottom beam and the steel support at the same time, the upper flange is subjected to the local pressure and shear force from the steel support, and the lower flange is subjected to the axial force, bending moment and shear force from the bottom beam. stress state. After the grouting material is poured around the web, its local pressure bearing performance and shear bearing capacity are greatly improved. Therefore, the flexural stiffness of the node domain is improved, and the shear capacity is improved. The integrity of the plate-column-joint and the integrity of the joint domains on both sides is enhanced by the bench-shaped tie-bar and the slab-column tie-bar.

At the same time, in order to meet the design principle of "strong joints and weak members", that is, to strengthen the beam-column joints and make the I-shaped steel beams connected to the joints fail before the joints. In the beam-column joint involved in the present invention, the π-shaped connecting piece is connected with the web connecting plate and the square steel tube recycled concrete column by welding, and is connected with the H-shaped steel beam by bolts. After welding, bolt shearing and weld cracking are both brittle failures. Therefore, it is necessary to ensure sufficient safety reserves for welds and bolts in the design stage. The failure mode of the joint should be designed as the deformation failure of the beam end. The failure position of the steel beam under the action of the earthquake is concentrated at the bolt hole of the beam flange, where the section of the steel beam flange will experience the process from yielding to fracture, which is a relatively slow and significant process. The deformation process has ideal ductile failure characteristics. The node of the present invention is a π-shaped connector in the main energy-consuming area of earthquake action. Under the action of reciprocating load, the flanges of the upper and lower I-beam cantilever short beams of the π-shaped connector are deformed to consume part of the seismic energy. The web of the cantilevered short beam will act as a stiffener to form a tension-compression rod truss system connecting the beam ends, which will consume part of the seismic energy while controlling the deformation of the joints. With the increase of the horizontal seismic action, the π-shaped connector, which is the first seismic defense line of the node, fails, and the web connecting plate, as the second seismic defense line, will continue to work to prevent the I-shaped steel beam from collapsing. At this time, the floor slabs in the node area are pressed against each other, and the crack between the beam end floor slab and the wall becomes wider or even completely cracked. This process lasts for a long time, which is conducive to the evacuation of personnel. Since there is no direct relationship between different beam-column nodes, failure of one node will not cause failure of other nodes at that location, so it conforms to the design principle of "strong column and weak beam".

Adopting the concrete-filled steel tube column-H-shaped steel beam-steel support-π-shaped connecting piece of the present invention has the advantages of firm connection at the bottom of the middle column, good integrity, convenient assembly, and green environmental protection. Steel frame and light steel truss residential building system beam-column assembly is a new type of node connection.

The above is a typical embodiment of the present invention, and the implementation of the present invention is not limited thereto.

Claims (10)

1. a concrete-filled steel tube column-H-shaped steel beam-steel support-π-shaped connector combined type middle column bottom node, is characterized in that: the column plate tie bar (2) is welded on the light-duty square steel tube recycled concrete column (1) The upper part is used to connect the prefabricated recycled concrete floor slab (15); the π-shaped connecting piece (4) is composed of the upper limb (8) of the π-shaped connecting piece, the lower limb (9) of the π-shaped connecting piece and the rectangular bottom plate (10), wherein the rectangular bottom plate (10 ) is a steel plate with a rectangular hole in the middle, the upper limb (8) of the π-shaped connecting piece and the lower limb (9) of the π-shaped connecting piece are fully welded on the rectangular bottom plate (10) respectively; The four corners of the outer edge of the rectangular bottom plate (10) on the π-shaped connector (4) are welded with the light-duty square steel pipe recycled concrete column (1) to weld the steel pipe wall to form four fillet welds on the outer edge, and the rectangular bottom plate ( 10) The four sides of the inner side opening are welded with the light-weight square steel pipe recycled concrete column (1) to form four fillet welds on the inner edge, and the light-weight square steel pipe recycled concrete column (1) and a single π-shaped connector (4) pass through The inner side and the outer side are connected with a total of eight fillet welds; the web connecting plate (5) is welded to the steel pipe wall of the light-weight square steel pipe recycled concrete column (1) through two right-angle fillet welds through the inner opening of the rectangular bottom plate (10); The upper and lower flanges of the steel beam (3) are connected with the upper limb (8) and the lower limb (9) of the π-shaped connecting piece of the π-shaped connecting piece (4) by 30mm long high-strength bolts (6); the H-shaped steel beam ( 3) The web and the web connecting plate (5) are connected by 30mm long high-strength bolts (6); the prefabricated steel support (11) is connected by 30mm long high-strength bolts (6) and 70mm through high-strength bolts (12) and π-shaped connectors The upper limb (8) is connected; the prefabricated recycled concrete floor slab (15) is connected with the H-shaped steel beam (3) through the floor shear bolts (7) and the high-strength grouting material; the prefabricated recycled concrete floor slab (15) is connected by the column-slab tie bars ( 2), the I-shaped bench tie steel bars (13) and the floor steel bars (16) are bound to each other and finally connected by high-strength pouring grouting material; the grouting material support plate (14) is pre-buried in the prefabricated recycled concrete floor slab (15); the I-shaped bench The tie reinforcement (13) is fixed at the web of the upper limb (8) of the π-shaped connector by 70mm through high-strength bolts (12), and is bound with the floor reinforcement (16). After high-strength grouting is poured, the upper limb of the π-shaped connector is made (8) It is integrated with the prefabricated recycled concrete floor slab (15). 2. A kind of CFST column according to claim 1-H-shaped steel beam-steel support-π-shaped connector combined type middle column bottom node, is characterized in that: described light-duty square steel tube recycled concrete column (1) The square steel pipe in the middle adopts square hot-rolled seamless steel pipe; the inside is filled with recycled concrete. 3. A kind of CFST column-H-shaped steel beam-steel support-π-shaped connector combined type middle column bottom node according to claim 1, is characterized in that: described column-plate tie bars (2) are belts Rebar with bent anchor ends. 4. A kind of CFST column according to claim 1-H-shaped steel beam-steel support-π-shaped connector combined type middle column bottom node, it is characterized in that: described H-shaped steel beam (3) is light steel The load-bearing member in the frame structure; in the light steel composite structure, the hot-rolled H-beam is used as the main beam or the secondary beam. 5. A kind of CFST column-H-shaped steel beam-steel support-π-shaped connector combined type middle column bottom node according to claim 1, characterized in that: the web connecting plate (5) is a rectangular steel plate , the length is the same as the length of the upper limb (8) of the π-shaped connecting piece and the lower limb (9) of the π-shaped connecting piece, the width is 80% of the height of the rectangular hole of the rectangular bottom plate (10), and the thickness is equal to the thickness of the web of the H-shaped steel beam (3); One side of the web connecting plate (5) is vertically welded to the column wall of the light-weight square steel tube recycled concrete column (1) through two vertical fillet welds through the rectangular hole in the center of the rectangular bottom plate (9); the web connecting plate (4) ) is connected to the web of the H-beam (3) through a 30mm long high-strength bolt (6). 6. A kind of CFST column-H-shaped steel beam-steel support-π-shaped connecting piece combined type middle column bottom node according to claim 1, is characterized in that: described floor slab shear studs (7) are reinforced The structure connecting the H-shaped steel beam (3) with the prefabricated concrete slab acts as a floor shear key. After the prefabricated recycled concrete floor slab (15) is assembled, high-strength grouting material is poured at the reserved holes for the floor slab shear studs (7), and the completion is completed. The connection between the H-shaped steel beam (3) and the prefabricated recycled concrete floor slab (15). 7. A kind of CFST column-H-shaped steel beam-steel support-π-shaped connector combined type middle column bottom node according to claim 1, is characterized in that: the π-shaped connector (4) passes through the outer fillet weld And the inner fillet weld and the light-weight square steel tube recycled concrete column (1) are connected by stick welding, and the quality control level of the weld shall be Class I or Class II. 8. A kind of CFST column-H-shaped steel beam-steel support-π-shaped connector combined type middle column bottom node according to claim 1, characterized in that: the rectangular bottom plate (10) is a center opening rectangular steel plate; The steel support (11) is a hot-rolled H-section steel, and is arranged between two adjacent light-duty square steel tube recycled concrete columns (1) at an angle of 60° to 45°; the flange width of the steel support (11) is connected with a pi shape The upper limbs (8) are equal. 9. A kind of CFST column-H-shaped steel beam-steel support-π-shaped connecting piece combined type middle column bottom node according to claim 1, it is characterized in that: described I-shaped bench tie bar (13) is A prefabricated three-dimensional reinforcement cage; an I-shaped bench-tie steel bar (13) is composed of two parts: a horizontally-tie bow-shaped steel bar mesh and a longitudinally-tie-tie bar; The middle transverse connecting steel bar is composed; The grouting material support plate (14) is a thin steel plate welded with pre-embedded anchoring steel bar hooks on three sides. 10. A concrete-filled steel tubular column-H-shaped steel beam-steel support-π-shaped connector combined type middle column bottom node method is characterized in that: the concrete practice of the method is as follows: Step 1: Factory prefabricated light-weight square steel tube recycled concrete column (1), column-plate tie bars (2), select the corresponding size square steel tube and steel plate, cut, grind, and open the bottom to weld the basic connecting plate at the bottom, and then internally The recycled concrete is poured, and the production of the square steel tube recycled concrete column (1) is completed after curing; the fabricated column-slab tie bars (2) are welded to the corresponding positions on both sides of the light-duty square steel tube recycled concrete column (1); Step 2: Process the π-shaped connector (4) and the web connection plate (5) in the factory workshop, first select the finished hot-rolled I-beam of the corresponding size, and cut, grind and punch to make the π-shaped connector. For the upper limb (8) and the lower limb (9) of the π-shaped connecting piece, a rectangular bottom plate (10) is made by cutting and drilling a hot-rolled steel plate of a corresponding thickness; the upper limb (8) and the lower limb (9) of the π-shaped connecting piece are ) is welded with the rectangular bottom plate (10) to make a π-shaped connecting piece (4); a steel plate of corresponding size and strength is selected to be cut and drilled to form a web connecting plate (5); Step 3: Weld the π-shaped connector (4) and the web connecting plate (5) to the corresponding positions on both sides of the light-duty square steel tube recycled concrete column (1) in the factory workshop; firstly, weld the π-shaped connector (4) To the light-duty square steel tube recycled concrete column (1), the π-shaped connector (4) is connected to the side of the light-duty square steel tube recycled concrete column (1) by welding through the outer and inner fillet welds. Therefore, the π-shaped connector ( 4) The length of the weld is fully ensured by connecting two circles of rectangular full fillet welds to the square steel tube column, which fully meets the shear bearing capacity and flexural bearing capacity of the weld at the node; then the web is connected to the plate (5) Weld to the square steel pipe column through the central hole of the rectangular base plate (10); Weld the nuts to the bolt hole positions of the upper limb (8) of the π-shaped connector and the lower limb (9) of the π-shaped connector to prepare for installing the bolts; Step 4: Set up a stiffener to weld on the H-shaped steel beam (3), and the thickness of the stiffening rib is not less than the thickness of the web of the H-shaped steel beam (3); process the upper and lower flanges of the H-shaped steel beam (3) according to the design position. Bolt holes in the web; finally weld the studs on the top surface of the H-beam (3); Step 5: The factory processes the prefabricated steel support (11), selects the hot-rolled H-section steel that meets the cross-sectional size requirements, grinds and cuts it to the corresponding size; ;Weld the formed steel support to the bottom gusset plate; the prefabricated steel support is finished; Step 6: Make the grouting material pallet (14) and the prefabricated recycled concrete floor slab (15), the factory selects the finished steel plate and cuts it into corresponding sizes, and processes the steel bars for anchoring on the grouting material pallet (14) by cutting, bending and other processes Bending hook, spot welding the steel bar hook to the steel plate to complete the grouting material support plate; make and bind the floor steel reinforcement, support the floor plate formwork, place the grouting material support plate in the opening, pour the floor slab recycled concrete, and maintain the molding; Step 7: Install the light-duty square steel tube recycled concrete column (1) with the π-shaped connector (4) and the web connecting plate (5) on the construction site, and install the steel tube concrete column to the foundation through the foundation connecting plate; Triangular notches are cut up and down at the end of the H-shaped steel beam (6), and the H-shaped steel beam (3) is slid between the π-shaped connecting pieces (4) of the steel pipe columns on both sides, so that the π-shaped connecting pieces (4) and the web The bolt holes on the connecting plate (5) are aligned with the bolt holes of the H-shaped steel beam (3), and are fastened with high-strength bolts; Step 8: Install the prefabricated recycled concrete floor slab to the corresponding position; Step 9: Install the prefabricated steel support (11) to the corresponding position through high-strength bolts; Step 10: Place the I-shaped bench tie bars (13) at the corresponding positions, and tighten the 70mm through high-strength bolts (13) to fix the I-shaped bench tie bars (13) at the web position of the upper limb (8) of the π-shaped connector ; Bind the transverse bow-shaped tie bars at both ends of the I-shaped bench tie bars (13) to the floor steel bars (16); ; The eleventh step: pour high-strength grouting material on the floor shear studs (7), the upper limbs of the π-shaped connectors (8), the I-shaped bench tie bars (13), and the grouting material pallets (14), etc. Completion of subsequent construction.

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