Fabricated unbonded prestressed cross beam column connecting structure and construction method thereof

Abstract

The invention relates to the technical field of fabricated buildings, in particular to a fabricated unbonded prestressed cross beam column connecting structure and a construction method thereof, the connecting structure comprises a prefabricated column, a combined steel rib beam, a superposed T beam, an unbonded prestressed tendon and an anti-hogging moment rib plate, and the construction technological process comprises on-site surveying and setting out and on-site hoisting of the prefabricated column; checking the position of the combined steel rib beam, and grouting a sleeve; hoisting the superposed T beam, and pre-penetrating a middle bolt; reinforcing steel bars in the beam-column joints are treated, and unbonded prestressed tendons are arranged; bolts are perforated, and anti-hogging moment rib plates are installed; hoisting the laminated slab, and mounting an aluminum mold at a beam-column joint; binding reinforcing steel bars of the laminated slab, and checking and accepting a hidden project; integrally pouring concrete of the beams, the plates and the columns, and tensioning and anchoring the unbonded prestressed tendons; and flow construction is conducted, and the steps are repeated till all structure construction is completed. Compared with a traditional construction method, the construction method has the advantages that the anti-seismic performance is remarkably improved, the construction period is shortened by about 65% or above, the construction cost is reduced by about 40%, and the green construction technical standard requirement is met.

Description

Technical Field

[0001] The present invention relates to the technical field of prefabricated buildings, and particularly to a prefabricated unbonded prestressed cross beam-column connection structure and a construction method thereof. Background Art

[0002] At present, the promotion of prefabricated buildings in China is just in the development stage, and the pace of promoting prefabricated buildings in various regions is relatively slow. There is still a large gap compared with the relevant requirements for developing green buildings and advanced construction methods. The construction technology system is not yet perfect. Through continuous improvement, it is necessary to achieve advanced technology, comprehensively consider construction costs and actual industrial production capacity, and gradually realize the real transformation and change of the prefabricated building construction method, and comprehensively promote the development of building industrialization.

[0003] In order to achieve the equivalent cast-in-place performance of precast concrete building structures, currently in China, cast-in-place concrete bonding layers are mainly used to strengthen the connection between precast components. A large number of on-site wet operations bring common technical problems such as uneven quality and low construction efficiency. Therefore, it is necessary to seek a new type of reliable connection technology to avoid on-site wet operations and achieve efficient and high-quality construction. Innovate the design of prefabricated construction structures, optimize the hoisting and positioning process methods, establish a new technology system for prestressed cross continuous beams in precast concrete structures, promote the transformation of building production methods, conform to the people-oriented concept, pay attention to environmental protection, and enhance social benefits.

[0004] The research and application of new prefabricated construction technologies have become one of the important topics in the current industry development. The scientific and technological team of Jiangsu Vocational and Technical College of Engineering and Jiangsu Shenggong Construction Group Co., Ltd. and others have made important contributions to the industry development in "Key Technologies for Complete Sets of Prefabricated Building Construction" in the early stage and formed a systematic number of key technology systems. In order to solve the problems in prefabricated construction such as large installation errors, many construction processes, bearing reliability of beam-column joints, difficult installation adjustment, high construction costs, difficult construction quality assurance, and environmental protection, our team, on the premise of deeply studying the technologies of relevant scholars, proposed "a prefabricated unbonded prestressed cross beam-column connection structure and a construction method thereof". This technology is the research result of the Nantong Science and Technology Plan Livelihood Project jointly undertaken by Jiangsu Vocational and Technical College of Engineering and Nantong Construction Project Quality Supervision Station: Research and Application of Key Technologies for Prestressed Cross Continuous Beam Construction in Prefabricated Buildings (Project No.: JCZ21075). It is hoped that through school-enterprise cooperation, a relatively mature series of new structures, new processes, and new methods for prefabricated construction can be formed, and joint efforts can be made for the application of new technologies in the field of prefabricated buildings in China, innovate structural design, optimize construction technology, and jointly contribute to the high-quality development of the transformation of the construction industry in China. Summary of the Invention

[0005] The object of the present invention is to provide an assembled non-bonded prestressed cross beam-column connection structure and a construction method thereof, so as to solve the problems raised by the background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an assembled non-bonded prestressed cross beam-column connection structure, comprising a prefabricated column, a composite steel rib beam, a superimposed T-beam, prestressed tendons and a negative bending moment resistant rib plate, wherein a composite steel rib beam is arranged inside the upper end of the prefabricated column, a superimposed T-beam is arranged on the upper part of the composite steel rib beam, prestressed tendons are arranged inside the superimposed T-beam, and a negative bending moment resistant rib plate is fixed at the upper end of the superimposed T-beam by bolts, prestressed tendons are arranged vertically and horizontally at the connection node between the prefabricated column and the superimposed T-beam, and the node connection is completed by post-cast concrete at the beam-column joint.

[0007] Preferably, the prefabricated column and the composite steel rib beam are integrally formed in a PC factory. The composite steel rib beam is composed of an I-shaped steel beam and a supporting panel. The I-shaped steel beam and the supporting panel are an integrated structure and are pre-buried in the top of the prefabricated column during the production process of the prefabricated column in the PC factory. The width of the flange plate of the I-shaped steel beam is 80mm-100mm, the height of the web is 120mm-160mm, the thickness of the wing plate and the web is 20mm-35mm, the design width of the supporting panel is equal to the cross-sectional width of the web beam at the lower end of the composite T-beam, the thickness of the supporting panel is 25mm-40mm, the length of the overall composite steel rib beam extending out of the side of the prefabricated column is 550mm-800mm, and the top surface of the composite steel rib beam is flush with the top surface of the prefabricated column concrete; during the integrated forming process of the prefabricated column and the composite steel rib beam in the PC factory, the collision problem between the composite steel rib beam and the designed steel bars at the top of the prefabricated column is solved by reserving holes in the composite steel rib beam.

[0008] Preferably, the composite T-beam is prefabricated in a PC factory and consists of a wing beam part and a web beam part. The overall composite T-beam height is not less than 500 mm, the wing beam height of the prefabricated part is not less than 120 mm, and the height does not include the post-casting section. The wing beam width is not less than 600 mm, the web beam width is not less than 250 mm, and the web beam height is not less than 350 mm. Ordinary steel bars and prestressed bars are provided inside the composite T-beam, and the specific size is determined according to the structural force design.

[0009] Preferably, the composite T-beam is placed on the upper part of the combined steel rib beam. The end of the composite T-beam is placed on the precast column for at least 10 mm. The common steel bars extending out from the end of the composite T-beam are anchored into the post-cast section at the top of the precast column, and the anchorage length is not less than 450 mm. To enhance the seismic performance of the beam-column joint, an anchorage plate is provided at the end of each common steel bar extending out from the composite T-beam, and it is set with 100% quantity; prestressed steel bars are provided at the lower part of the web beam and the end of the wing beam in the composite T-beam. Unbonded prestressed steel bars can be used for the prestressed steel bars. It is designed that the unbonded prestressed steel bars inside the composite T-beam are integrally formed during the precast production process of the composite T-beam. The layout of the prestressed steel bars shall not collide with the positions of the common steel bars inside the composite T-beam. When necessary, BIM technology software is used for auxiliary design and PC factory component production and manufacturing.

[0010] Preferably, to improve the negative moment bearing capacity at the beam-column joint, a negative moment resisting rib plate is provided at the beam-column joint. The negative moment resisting rib plate is fixed to the top of the composite T-beam by bolts. The negative moment resisting rib plate is located within the composite layer of the composite T-beam. The cutting length of the negative moment resisting rib plate is not less than the side length of the precast column in the same direction + 2000 mm, and it is arranged in a continuous length. The negative moment resisting rib plate is composed of a web and enlarged cross-section plates at both ends. The minimum dimensions of the web and the enlarged cross-section plates at both ends are not less than 12 mm, which is determined according to the specific working conditions.

[0011] Preferably, according to the building structure position relationship, the precast column and the combined steel rib beam integrally formed at its upper end are divided into beam-column joints with a combined steel rib beam integrally formed on one side, beam-column joints with a combined steel rib beam integrally formed on both sides, beam-column joints with a combined steel rib beam integrally formed on three sides, and beam-column joints with a combined steel rib beam integrally formed on four sides; according to the force characteristics, double-cross joints are designed in the structure, and two types of beam-column joint cross designs and prestressed cross layouts are adopted. The effect of negative moment resistance at the beam-column joint is mainly designed to improve the seismic performance of the joint.

[0012] Preferably, to strengthen the connection reliability between the composite T-beam and the precast column and improve the hoisting and positioning efficiency of the composite T-beam, bolt holes for docking with the composite T-beam are provided on the combined steel rib beam. The diameter of the bolt holes is equal to the diameter of the reserved bolt through holes inside the composite T-beam and is not less than 20 mm.

[0013] The present invention also provides a construction method for an assembled unbonded prestressed cross-beam-column connection structure. The construction process flow is as follows: production, transportation, and finished product protection of PC components --- on-site measurement and layout, on-site hoisting of precast columns --- position checking of combined steel rib beams, sleeve grouting --- hoisting of composite T-beams, pre-passing of middle bolts --- reinforcement treatment in beam-column joints, layout of unbonded prestressed tendons --- bolt perforation, installation of anti-negative moment rib plates --- hoisting of composite slabs, installation of aluminum formwork at beam-column joints --- steel bar binding of composite slabs, acceptance of concealed works --- integral pouring of concrete for beams, slabs, and columns, tensioning and anchoring of unbonded prestressed tendons --- flow construction, repeating the above steps until all structural construction is completed.

[0014] Preferably, the specific technical solution is as follows:

[0015] Step S1: Production, transportation, and finished product protection of PC components

[0016] First, deepen the design of precast columns and composite T-beams according to the drawings, use BIM technology software to assist in designing the positional relationship between precast columns and the combined steel rib beams at their upper ends, focus on reviewing the collision relationship between the internal steel bars of precast columns and the combined steel rib beams, accurately cut the materials, and integrally prefabricate and form them; during the prefabrication production process of composite T-beams, ensure the post-cast height of the upper part of the composite T-beams, and the post-cast section steel bars meet the requirements of steel bar anchoring and force-bearing at the beam-slab joints. Focus on checking the positional relationship between the internal prestressed tendon ducts of the composite T-beams and the layout position of the designed steel bars of the composite T-beams, as well as the reservation of bolt holes inside the composite T-beams. Without affecting the force-bearing, in principle, ordinary steel bars should give way to prestressed tendons to avoid affecting the construction quality and bearing capacity; after the precast columns, composite T-beams, and other component parts are integrally prefabricated and formed in the PC factory, they can be lifted when their concrete strength reaches more than 85% of the design strength, and can be loaded and transported when they reach 100% of the design strength. During the transportation process, focus on protecting the precast columns and the combined steel rib beams integrally formed at their upper ends, and there should be no appearance quality problems such as deformation, damage, and affecting component hoisting of the precast components due to transportation reasons, and do a good job in the finished product protection work;

[0017] Step S2: On-site measurement and layout, on-site hoisting of precast columns

[0018] After the prefabricated components arrive at the site, organize special personnel for acceptance. Components with unqualified appearance quality are not allowed to enter the site, and strictly control the quality. After the prefabricated components enter the site, according to the on-site measurement progress arrangement, reasonably organize flowing construction, hoist the prefabricated column grid in sections, and use mechanical hoisting for each prefabricated column according to the position line and control line of the prefabricated column on the top surface of the foundation. Adopt an inclined adjustable steel support to temporarily fix and position the prefabricated column, and strictly check and verify the plane position and top elevation of the combined steel rib beam after each prefabricated column is in place. The on-site hoisting and positioning of the prefabricated column adopt the "secondary positioning" method, that is, for the first time, adjust the hoisting and positioning elevation of each prefabricated column according to the elevation of the base surface, accurately align the steel sleeve at the bottom of the prefabricated column with the vertical steel bars of the base, and use an inclined adjustable steel support to initially fix the prefabricated column in place. Then, check and verify the top elevation of the combined steel rib beam formed integrally with the prefabricated column, check and verify the top elevation of each combined steel rib beam one by one, and control the error within 2 mm. Finally, adjust the verticality of each prefabricated column, tighten the inclined steel support, and complete the hoisting of the prefabricated column. During the whole process, do a good job in protecting the combined steel rib beam, arrange special personnel for inspection and acceptance, and keep acceptance records.

[0019] Step S3: Check and verify the position of the combined steel rib beam, and grout the sleeve

[0020] The position of the combined steel rib beam directly affects the subsequent hoisting and positioning of the precast composite T-beam. Since the precast composite T-beam is relatively large in size, it is difficult to make adjustments after being in place, which directly affects the overall progress arrangement. Therefore, after each prefabricated column in the construction section is accurately hoisted and positioned, check and verify and adjust the position relationship and elevation of the combined steel rib beam at each beam-column joint. After it is confirmed to be correct, grout immediately. For the beam-column joints with combined steel rib beams formed integrally on both sides, the beam-column joints with combined steel rib beams formed integrally on three sides, and the beam-column joints with combined steel rib beams formed integrally on four sides, during the on-site construction process, the position relationship and top elevation of the adjacent combined steel rib beams at the same joint should also be checked and verified. When the error is large, the hoisting error of the prefabricated column can be integrated by adjusting the position relationship of the precast composite T-beam. The high-strength low-shrinkage and slightly expanding grouting material is used for grouting the steel sleeves at the bottom of the on-site prefabricated columns. Use it immediately after mixing, and pour it in one go. Arrange special personnel to stand by on-site to ensure the grouting quality of the steel sleeves at the bottom of each prefabricated column, and do a good job in the acceptance and record of the concealed project of the steel sleeve grouting.

[0021] Step S4: Hoist the composite T-beam and pre-pierce the middle bolts

[0022] To achieve the efficient hoisting and positioning of the composite T-beam, after the combined steel rib beams of each section are checked and verified without errors, the composite T-beam can be hoisted; steel backing plates are embedded at the bottom of the web beam of the designed composite T-beam during the prefabrication process in the PC factory. During the on-site hoisting process, after the composite T-beam is finally positioned, it is necessary to ensure that its end is at least placed 10 mm on the end face of the precast column. After the plane position and elevation of the composite T-beam are checked and verified without errors after positioning, the steel backing plate at the bottom of the composite T-beam is connected and fixed to the combined steel rib beam by the method of full welding on three sides to achieve the effect of not setting or setting fewer supports under the composite T-beam. The composite T-beam is hoisted, positioned and fixed, which improves the hoisting efficiency and reduces the construction cost; after the composite T-beam is hoisted, positioned and fixed, high-strength bolts are passed through the bottom of the combined steel rib beam, and all the middle bolts on the composite T-beam are sequentially passed through. The number of high-strength bolts designed on each side of the combined steel rib beam is not less than 3, which can improve the shear bearing capacity at the beam-column joint. Adopt the method of "first passing the high-strength bolts within the range of the combined steel rib beams at both ends, and then passing the high-strength bolts in the middle section of the web beam on the composite T-beam", that is, controlling both sides first. The perforation of the bolts in the middle section of the web beam on the composite T-beam is not restricted by the hoisting error, and the bolts in the middle section of the web beam on the composite T-beam are evenly arranged, with the spacing not exceeding 450 mm and not less than 5.

[0023] Step S5: Reinforcement treatment in the beam-column joint and layout of unbonded prestressed tendons

[0024] After the composite T-beam is hoisted and positioned, the beam-column joint and the upper cast-in-place section of the composite T-beam can be processed; first, all the ordinary steel bars of the composite T-beam are effectively anchored into the beam-column joint, and the anchorage length is not less than 35d (d is the diameter of the ordinary steel bar of the composite T-beam) and not less than 800 mm. When the anchorage length of the ordinary steel bar cannot meet the design requirements, an anchorage plate can be set at the end of the ordinary steel bar; the steel bars in the beam-column joint and the upper cast-in-place section of the composite T-beam should be arranged continuously, and the diameter of the main stress-bearing steel bar is not less than 30 mm, and the requirements for the clear distance between steel bars for the later concrete pouring should be met; for the layout requirements of prestressed tendons, while processing the steel bar installation at the beam-column joint, the prestressed tendons inside can be laid synchronously; the unbonded prestressed tendons are passed through the holes from one end of the composite T-beam to the beam-column joint by the traction method, and then passed through the holes from the inside of the beam-column joint to the other end of the composite T-beam, and are cross-arranged to meet the linear trend of the prestressed tendons, and no fixed supports are required. Do a good job in the acceptance of concealed works.

[0025] Step S6: Bolt perforation and installation of anti-negative moment rib plates

[0026] After the unbonded prestressed tendons are laid out, the high-strength bolts can be inserted through the wing beams of the composite T-beam. The high-strength bolts on both side wing beams are arranged in a "staggered wave" pattern, and are asymmetrically set to strengthen the shear resistance of the composite T-beam. Then, the negative moment resisting rib plates in the upper post-cast section of the composite T-beam are installed. The installation holes on the negative moment resisting rib plates are aligned with each high-strength bolt one by one for reliable fixation. Within the beam-column joint and 1000 mm on both sides thereof, the negative moment resisting rib plates shall be arranged continuously, and there shall be no incomplete installation phenomena such as splicing and welding of the negative moment resisting rib plates within this range, so as not to affect the mechanical properties of the overall structure. The number of negative moment resisting rib plates in the same direction is not less than 3, and their installation does not affect the extension of the top reinforcement of the precast column and the subsequent concrete pouring process. The process acceptance and record work shall be done well;

[0027] Step S7: Hoisting of composite slabs and installation of aluminum formwork at beam-column joints

[0028] The design adopts integral cast-in-place forming of beams, slabs and columns in one piece. On the basis of completing the above processes, the composite slabs are hoisted in sections, modules and intervals. The ends of the composite slabs are fixed to the high-strength bolts in the upper composite layer or post-cast section of the composite T-beam in the form of local embedded connecting steel plates. The end reinforcement of the composite slabs at other positions extends into the composite layer of the composite T-beam. Additional reinforcement is provided at the intersection of the composite T-beam and the composite slab. The cutting length of the additional reinforcement is not less than 1200 mm, the diameter is not less than 10 mm, and the spacing does not exceed 100 mm. The additional reinforcement is placed on the negative moment resisting rib plates in the composite layer, and each additional reinforcement shall be spot-welded to the negative moment resisting rib plates one by one; To meet the subsequent concrete pouring process, aluminum formwork is quickly assembled at the beam-column joints. When installing the aluminum formwork, elastic sealing rubber strips are pasted on the contact surfaces with the precast columns and composite beams. The aluminum formwork is fixed by screwing tightly with the embedded internal thread sleeves on the composite T-beam and precast columns to achieve the purpose of quick installation;

[0029] Step S8: Binding of steel bars of composite slabs and acceptance of concealed works

[0030] According to the construction plan, double-layer and double-way steel bar meshes are used for on-site hoisting construction of composite slabs. After the composite slabs are hoisted in place, after handling the steel bar connection at the joints of the composite slabs and the composite T-beam, the upper steel bar mesh is bound on the upper truss bars of the composite slabs. The diameter of the distribution steel bars of the upper steel bar mesh is not less than 10 mm, and the spacing of the distribution steel bars does not exceed 150 mm. The distribution steel bars at the joints of the composite slabs and the composite T-beam shall be arranged continuously and appropriately densified, and the densified spacing does not exceed 100 mm;

[0031] Step S9: Integral pouring of concrete for beams, slabs and columns, tensioning and anchoring of unbonded prestressed tendons

[0032] After all the above-mentioned processes are completed and pass the acceptance inspection, the concrete of beams, slabs and columns can be integrally poured. There shall be no construction joints at the beam-column joints. The concrete strength shall not be lower than C30. The concrete pouring at the joints of precast columns and composite T-beams and at the joints of composite T-beams and composite slabs shall be vibrated intensively to ensure the quality of joint concrete pouring, and the curing time shall not be less than 7 days. For the tensioning and anchoring of unbonded prestressed tendons on site, after all the structures of this layer are constructed and the concrete strength reaches 100% of the design strength, the tensioning and anchoring of unbonded prestressed tendons can be carried out. 1.03σcom over-tensioning is adopted and symmetric tensioning is carried out. There is no need for grouting. The two ends of the unbonded prestressed tendons are anchored at the end or bottom of the composite T. Special personnel shall be assigned to supervise the process and acceptance records shall be made.

[0033] Step S10: Carry out flow construction, and repeat steps 1 to 9 until all the structure construction is completed.

[0034] For on-site hoisting construction, the hoisting connection of precast columns and composite T-beams has become the key point of the technical solution. Doing a good job in the seismic design and construction of beam-column joints is a remarkable manifestation of the structural innovation and process optimization of the technical solution. For engineering projects with a beam-column span exceeding 12m, special plan certification shall be carried out to ensure the operation safety of the hoisting project. According to the technical solution, the flow construction organization form is adopted, and the above-mentioned technological steps 1 to 9 are repeated until all the structural hoisting construction is completed, and finally project acceptance and material filing are carried out.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows: The technical solution of the present invention follows the principle of "integrated precast column design with combined steel rib beams, enhanced load-bearing capacity of composite T-beams, staggered wave-shaped high-strength bolt shear resistance layout, anti-negative moment rib plate joint connection, cross control of longitudinal and transverse prestressed tendons, and one-time forming of post-cast concrete". Compared with the traditional construction method, the seismic performance is significantly improved, the construction period is saved by more than 65%, the construction cost is reduced by about 40%, it meets the requirements of green construction technology standards, strengthens the research and development and application of new technologies, and provides favorable technical support for the high-quality development of the prefabricated construction technology field in China. Description of the Drawings

[0036] Figure 1 It is a structural schematic diagram of a precast column with integrated forming of combined steel rib beams on one side of the connection structure of the present invention;

[0037] Figure 2 It is a schematic diagram of the combined steel rib beam of the connection structure of the present invention;

[0038] Figure 3 It is a schematic diagram of the composite T-beam of the connection structure of the present invention;

[0039] Figure 4 It is an installation schematic diagram of the anti-negative moment rib plate of the connection structure of the present invention;

[0040] Figure 5 It is a schematic structural view of a precast column integrally formed with combined steel rib beams attached to three sides of the connection structure of the present invention;

[0041] Figure 6 It is a schematic structural view of a precast column integrally formed with combined steel rib beams attached to four sides of the connection structure of the present invention;

[0042] Figure 7 It is a diagram showing the positional relationship between the composite T-beam and the combined steel rib beam of the connection structure of the present invention;

[0043] Figure 8 It is a schematic structural view of an embodiment of a precast column integrally formed with combined steel rib beams attached to both sides of the connection structure of the present invention;

[0044] Figure 9 It is a schematic structural view of an embodiment of a precast column integrally formed with combined steel rib beams attached to both sides of the connection structure of the present invention;

[0045] Figure 10 It is a flow chart of the construction process of the connection structure of the present invention;

[0046] Reference numerals: 1 - precast column, 2 - combined steel rib beam, 21 - support panel, 22 - I-shaped steel beam, 3 - composite T-beam, 31 - wing beam, 32 - web beam, 33 - prestressed tendon, 4 - negative bending resistance rib plate, 5 - bolt. Detailed implementation manners

[0047] Refer to Figures 1 to 9 , in the embodiment of the present invention, a prefabricated unbonded prestressed cross beam-column connection structure and its construction method are disclosed. The connection structure includes a precast column 1, a combined steel rib beam 2, a composite T-beam 3, a prestressed tendon 33, and a negative bending resistance rib plate 4. Refer to Figure 1 , the inside of the upper end of the precast column 1 is provided with a combined steel rib beam 2; Refer to Figure 7 , the upper part of the combined steel rib beam 2 is provided with a composite T-beam 3; Refer to Figure 3 , the inside of the composite T-beam 3 is provided with a prestressed tendon 33; Refer to Figure 4 , a negative bending resistance rib plate 4 is fixed to the upper end of the composite T-beam 3 by bolts 5; The prestressed tendons 33 are arranged vertically and horizontally at the connection node of the precast column 1 and the composite T-beam 3, and the node connection is completed in the form of post-cast concrete at the beam-column butt joint.

[0048] The composite T-beam 3 is prefabricated and formed in a PC factory, and is composed of a wing beam 31 part and a web beam 32 part. The overall height of the composite T-beam 3 is not less than 500 mm. The height of the precast part of the wing beam 31 is not less than 120 mm (excluding the post-cast section), the width of the wing beam 31 is not less than 600 mm, the width of the web beam 32 is not less than 250 mm, and the height of the web beam 32 is not less than 350 mm. The inside of the composite T-beam 3 is provided with ordinary steel bars and prestressed tendons 33,Figure 3 The red part in the middle is ordinary steel bar, and the specific sizes of the two are determined according to the structural force design.

[0049] The prefabricated column 1 and the composite steel rib beam 2 are integrally formed in the PC factory. The composite steel rib beam 2 is composed of an I-shaped steel beam 21 and a supporting panel 22. The I-shaped steel beam 21 and the supporting panel 22 are an integrated structure and are embedded in the top of the prefabricated column 1 during the production process of the prefabricated column 1 in the PC factory. The flange width of the I-shaped steel beam 21 is 80mm~100mm, the web height is 120mm~160mm, the flange and web thickness is 20mm~35mm, the design width of the supporting panel 22 is equal to the cross-sectional width of the web beam 32 at the lower end of the composite T-beam 3, the thickness of the supporting panel 22 is 25mm~40mm, the overall composite steel rib beam 2 extends out of the side of the prefabricated column 1 by 550mm~800mm, and the top surface of the composite steel rib beam 2 is flush with the concrete top surface of the prefabricated column 1. During the integrated forming process of the precast column 1 and the composite steel rib beam 2 in the PC factory, holes are reserved on the composite steel rib beam 2 to solve the collision problem with the designed steel bars at the top of the precast column 1.

[0050] The composite T-beam 3 is placed on the upper part of the composite steel rib beam 2, and the end of the composite T-beam 3 is placed on the prefabricated column 1 for at least 10mm. The ordinary steel bars extending outward from the end of the composite T-beam 3 are anchored into the post-casting section at the top of the prefabricated column 1, and the anchoring length is not less than 450mm. In order to strengthen the seismic performance of the beam-column node, each end of the ordinary steel bars extending outward from the composite T-beam 3 is provided with an anchor plate, and the number is set 100%. The lower part of the web beam 32 and the end of the wing beam 31 of the composite T-beam 3 are provided with prestressed tendons 33, and the prestressed tendons 33 can be unbonded prestressed tendons. The unbonded prestressed tendons inside the composite T-beam 3 are designed to be integrally formed during the prefabrication production process of the composite T-beam 3. The layout of the prestressed tendons 33 shall not collide with the ordinary steel bars inside the composite T-beam 3. If necessary, BIM technology software is used to assist in design and PC factory component production.

[0051] In order to improve the negative moment bearing capacity at the beam-column joint, a negative moment rib 4 is provided at the beam-column joint. The negative moment rib 4 is fixed to the top of the composite T-beam 3 by bolts 5. The negative moment rib 4 is located in the composite layer of the composite T-beam 3. The cutting length of the negative moment rib 4 is not less than the side length of the prefabricated column 1 in the same direction + 2000mm. It is arranged throughout the length. The negative moment rib 4 consists of a web and expanded section plates at both ends. The minimum size of the web and the expanded section plates at both ends is not less than 12mm, which is determined according to the specific working conditions.

[0052] The prefabricated column 1 and the composite steel rib beam 2 formed integrally at the upper end thereof are divided into the following according to the position relationship of the building structure: Figure 1 The beam-column node shown in the figure is formed by integrating a composite steel rib beam on one side. Figure 8 and Figure 9The beam-column joints integrally formed with combined steel ribs attached to both sides as shown, Figure 5 the beam-column joints integrally formed with combined steel ribs attached to three sides as shown, and Figure 6 the beam-column joints integrally formed with combined steel ribs attached to four sides as shown. According to the force characteristics, double-cross joints are designed in the structure, and two types are adopted: the cross design of beam-column joints and the prestressed cross layout. The effect of resisting negative bending moment at the beam-column joints is mainly designed to improve the seismic performance of the joints.

[0053] To enhance the connection reliability between the composite T-beam 3 and the precast column 1 and improve the hoisting and positioning efficiency of the composite T-beam 3, bolt holes for docking with the composite T-beam 3 are provided on each side of the combined steel ribs 2, and the diameter of the bolt holes is equal to the diameter of the reserved bolt perforations inside the composite T-beam 3 and not less than 20 mm.

[0054] The construction process flow of the above connection structure is as follows: production, transportation, and finished product protection of PC components --- on-site measurement and setting out, on-site hoisting of precast columns --- checking the position of combined steel ribs, sleeve grouting --- hoisting of composite T-beams, pre-piercing of middle bolts --- treatment of internal steel bars at beam-column joints, layout of unbonded prestressed tendons --- bolt piercing, installation of negative bending moment rib plates --- hoisting of composite slabs, installation of aluminum formwork at beam-column joints --- steel bar binding of composite slabs, concealed works acceptance --- integral pouring of concrete for beams, slabs, and columns, tensioning and anchoring of unbonded prestressed tendons --- flow construction, repeating the above steps until all structural construction is completed.

[0055] Based on the entire construction process flow, the specific technical solution of a construction method for an assembled unbonded prestressed cross beam-column connection structure is as follows:

[0056] Step S1: Production, transportation, and finished product protection of PC components:

[0057] First, carry out the detailed design of precast columns and composite T-beams according to the drawings. Use BIM technology software to assist in designing the positional relationship between precast columns and the composite steel rib beams at their upper ends. Focus on reviewing the collision relationship between the internal steel bars of precast columns and the composite steel rib beams, accurately cut the materials, and integrally prefabricate and form them. During the prefabrication production process of composite T-beams, ensure the post-cast height of the upper part of the composite T-beams, and ensure that the steel bars in the post-cast section meet the requirements for the anchorage and force-bearing of the beam-slab joints. Focus on checking the positional relationship between the internal prestressed tendon ducts and the designed steel bar layout positions in the composite T-beams, as well as the reservation of bolt holes inside the composite T-beams. Without affecting the force-bearing, in principle, ordinary steel bars should avoid prestressed tendons to prevent affecting the construction quality and bearing capacity. After the precast columns, composite T-beams and other component parts are integrally prefabricated and formed in the PC factory, they can be lifted when their concrete strength reaches more than 85% of the designed strength, and can be loaded and transported only when the strength reaches 100% of the designed strength. During the transportation process, special attention should be paid to protecting the precast columns and the integrally formed composite steel rib beams at their upper ends, and no appearance quality problems such as deformation, damage, and affecting the hoisting of components due to transportation reasons shall occur. Do a good job in the protection of finished products.

[0058] Step S2: On-site measurement and setting out, on-site hoisting of precast columns:

[0059] After the prefabricated component parts arrive at the site, organize special personnel for acceptance. Component parts with unqualified appearance quality shall not enter the site, and strictly control the quality. After the precast components enter the site, according to the on-site measurement progress arrangement, reasonably organize the flow construction, segmentally hoist the precast column grid, and mechanically hoist each precast column according to the position line and control line of the precast columns on the top surface of the foundation. Use inclined adjustable steel supports to temporarily fix the precast columns in place, and strictly check the plane position and top elevation of the composite steel rib beams after each precast column is in place. The on-site hoisting and positioning of precast columns adopt the "secondary positioning" method, that is, for the first time, adjust the hoisting and positioning elevation of each precast column according to the elevation of the base surface, accurately align the steel bar sleeves at the bottom of the precast column with the vertical steel bars of the base layer, and use inclined adjustable steel supports to preliminarily fix the precast columns that have been in place. Then, review the top elevation of the integrally formed composite steel rib beams of the precast columns, review the top elevation of each composite steel rib beam one by one, control the error within 2 mm, and finally adjust the verticality of each precast column, tighten the inclined steel supports, and complete the hoisting of the precast columns. Do a good job in protecting the composite steel rib beams throughout the process, arrange special personnel for inspection and acceptance, and keep acceptance records.

[0060] Step S3: Checking the position of the composite steel rib beams, sleeve grouting:

[0061] The position of the composite steel rib beam directly affects the subsequent hoisting and positioning of the precast composite T-beam. Since the precast composite T-beam is large in size, it is difficult to make adjustments after positioning, which directly affects the overall progress arrangement. Therefore, after the accurate hoisting and positioning of each precast column in the construction section, the position relationship and elevation of the composite steel rib beam at each beam-column joint are checked and adjusted. After ensuring that there is no error, grouting is immediately carried out. For the beam-column joints integrally formed with composite steel rib beams attached on both sides, the beam-column joints integrally formed with composite steel rib beams attached on three sides, and the beam-column joints integrally formed with composite steel rib beams attached on four sides, during the on-site construction process, the position relationship and top elevation of the adjacent composite steel rib beams at the same joint should also be checked. When the error is large, the hoisting error of the precast column can be integrated by adjusting the position relationship of the precast composite T-beam. The high-strength, low-shrinkage and slightly expanding grouting material is used for the grouting of the steel bar sleeves at the bottom of the on-site precast columns. It is used immediately after mixing and is poured in one go. Special personnel are arranged on-site to ensure the grouting quality of the steel bar sleeves at the bottom of each precast column and to do a good job in the acceptance and record of the concealed project of the steel bar sleeve grouting.

[0062] Step S4: Hoist the composite T-beam and pre-drill the middle bolts:

[0063] To achieve the efficient hoisting and positioning of the composite T-beam, after the verification of each section of the composite steel rib beam is correct, the composite T-beam can be hoisted. Steel backing plates are embedded at the bottom of the web beam of the designed composite T-beam during the precast production process in the PC factory. During the on-site hoisting process, after the composite T-beam is finally positioned, it is ensured that its end is at least placed on the end face of the precast column by 10 mm. After the plane position and elevation of the composite T-beam after positioning are verified to be correct, the steel backing plate at the bottom of the composite T-beam is connected and fixed to the composite steel rib beam by the full-weld method on three sides, so as to achieve the effect of setting no or fewer supports under the composite T-beam. The composite T-beam is hoisted, positioned and fixed, which improves the hoisting efficiency and reduces the construction cost. After the composite T-beam is hoisted, positioned and fixed, high-strength bolts are passed through the holes at the bottom of the composite steel rib beam, and all the middle bolts on the composite T-beam are passed through in turn. The number of high-strength bolts designed on each side of the composite steel rib beam is not less than 3, which can improve the shear bearing capacity at the beam-column joint. The method of "first passing the high-strength bolts within the range of the composite steel rib beams at both ends, and then passing the high-strength bolts in the middle section of the web beam on the composite T-beam" is adopted, that is, controlling the two sides first. The bolt passing of the middle section of the web beam on the composite T-beam is not restricted by the hoisting error, and the bolt passing of the middle section of the web beam on the composite T-beam is evenly arranged, with the spacing not exceeding 450 mm and not less than 5.

[0064] Step S5: Reinforcement treatment in the beam-column joint and layout of unbonded prestressed tendons:

[0065] After the composite T-beam is hoisted and positioned, the beam-column joint and the post-cast section at the upper part of the composite T-beam can be processed. First, effectively anchor all the ordinary steel bars of the composite T-beam into the beam-column joint. The anchorage length shall not be less than 35d (d is the diameter of the ordinary steel bar of the composite T-beam) and not less than 800 mm. When the anchorage length of the ordinary steel bar cannot meet the design requirements, an anchorage plate can be set at the end of the ordinary steel bar. The steel bars in the beam-column joint and the post-cast section at the upper part of the composite T-beam shall be arranged continuously. The diameter of the main stressed steel bar shall not be less than 30 mm, and the requirements for the clear distance between steel bars during the later concrete pouring shall be met. For the layout requirements of the prestressed tendons, while installing the steel bars at the beam-column joint, the prestressed tendons inside can be laid synchronously. The unbonded prestressed tendons are perforated from one end of the composite T-beam to the beam-column joint by the traction method, and then perforated from inside the beam-column joint to the other end of the composite T-beam, and arranged crosswise to meet the linear trend of the prestressed tendons, and no fixed supports are required. The acceptance work for the concealed project shall be done well.

[0066] Step S6: Bolt perforation and installation of the negative moment resisting rib plate:

[0067] After the unbonded prestressed tendons are laid out, the high-strength bolt perforation work for the wing beam part of the composite T-beam can be carried out. The high-strength bolts on both sides of the wing beam are arranged in a "staggered wave shape", and asymmetrically set to strengthen the shear resistance of the composite T-beam. Then, install the negative moment resisting rib plate in the post-cast section at the upper part of the composite T-beam, and align each installation hole on the negative moment resisting rib plate with each high-strength bolt for reliable fixation. Within the beam-column joint and 1000 mm on both its left and right sides, the negative moment resisting rib plate shall be arranged continuously, and there shall be no incomplete installation phenomena such as splicing and welding of the negative moment resisting rib plate within this range, so as not to affect the mechanical properties of the overall structure. The number of negative moment resisting rib plates in the same direction shall be not less than 3, and their installation shall not affect the extension of the steel bars at the top of the precast column and the later concrete pouring process. The process acceptance and recording work shall be done well.

[0068] Step S7: Hoisting of the composite slab and installation of the aluminum formwork at the beam-column joint:

[0069] The design adopts the integral cast-in-place forming of beams, slabs and columns. On the basis of completing the above processes, the laminated slabs are hoisted section by section, module by module and area by area. The ends of the laminated slabs are fixed to the upper laminated layer of the laminated T-beam or the high-strength bolts in the post-cast section by means of locally embedded connecting steel plates. The end reinforcement bars of the laminated slabs in other parts extend into the laminated layer of the laminated T-beam. Additional reinforcement bars are arranged at the joints between the laminated T-beam and the laminated slab. The cutting length of the additional reinforcement bars is not less than 1200 mm, the diameter is not less than 10 mm, and the spacing does not exceed 100 mm. The additional reinforcement bars are placed on the negative moment rib plates in the laminated layer, and each additional reinforcement bar should be spot-welded to the negative moment rib plate. In order to meet the subsequent concrete pouring process, aluminum formwork is quickly assembled at the beam-column joints. When installing the aluminum formwork, elastic sealing rubber strips are pasted on the contact surfaces with the precast columns and laminated beams. The aluminum formwork is fixed by screwing tightly with the embedded internal threaded sleeves on the laminated T-beam and precast columns to achieve the purpose of quick installation.

[0070] Step S8: Binding of reinforcement bars of the laminated slab, acceptance of concealed works:

[0071] According to the construction plan, double-layer and double-way steel bar meshes are used for the on-site hoisting construction of the laminated slabs. After the laminated slabs are hoisted in place and the steel bar connection at the joints between the laminated slabs and the laminated T-beams is well handled, the upper steel bar mesh is bound on the upper truss bars of the laminated slabs. The diameter of the distribution bars of the upper steel bar mesh is not less than 10 mm, and the spacing of the distribution bars does not exceed 150 mm. The distribution bars at the joints between the laminated slabs and the laminated T-beams should be arranged continuously and appropriately densified, and the densified spacing does not exceed 100 mm.

[0072] Step S9: Integral pouring of concrete for beams, slabs and columns, tensioning and anchoring of unbonded prestressed tendons:

[0073] After all the above processes are completed and accepted, the concrete for beams, slabs and columns can be integrally poured. There shall be no construction joints at the beam-column joints. The concrete strength is not less than C30. The concrete pouring at the joints between the precast columns and the laminated T-beams and at the joints between the laminated T-beams and the laminated slabs shall be vibrated intensively to ensure the quality of the joint concrete pouring, and the curing time is not less than 7 days. For the tensioning and anchoring of the on-site unbonded prestressed tendons, the tensioning and anchoring of the unbonded prestressed tendons can be carried out only when all the structural construction of this layer is completed and the concrete strength reaches 100% of the design strength. 1.03σcom over-tensioning is adopted and symmetric tensioning is carried out. No grouting is required. The two ends of the unbonded prestressed tendons are anchored at the end or bottom of the laminated T. Special personnel shall be assigned to supervise the process and acceptance records shall be made.

[0074] Step S10: Flow construction, repeat steps 1 to 9 until all structural construction is completed:

[0075] For on-site hoisting construction, the hoisting connection of precast columns and composite T-beams has become the focus of the technical solution. Doing a good job in the seismic design and construction of beam-column joints is a remarkable manifestation of the structural innovation and process optimization of the technical solution. For engineering projects with a beam-column span exceeding 12m, a special plan certification should be carried out to ensure the operational safety of the hoisting project. According to the technical solution, the flowing water construction organization form is adopted, and the above process steps 1 to 9 are repeated until the hoisting construction of all structures is completed, and finally the project acceptance and material filing are carried out.

[0076] In summary, the technical solution of the present invention follows the principle of "integrated design of composite steel rib beams and precast columns, enhanced load-bearing of composite T-beams, staggered wave-type high-strength bolt shear resistance layout, connection of anti-negative moment rib plate joints, cross control of longitudinal and transverse prestressed tendons, and one-time forming of post-cast concrete". Compared with the traditional construction method, the seismic performance is significantly improved, the construction period is saved by more than 65%, the construction cost is reduced by about 40%, the requirements of green construction technology standards are met, the research and development and application of new technologies are strengthened, and favorable technical support is provided for the high-quality development of the prefabricated construction technology field in China.

[0077] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An assembled non-bonded prestressed cross beam-column connection structure, characterized in that: It includes precast columns, composite steel rib beams, superimposed T-beams, prestressed tendons and negative moment resisting ribs. A composite steel rib beam is arranged inside the upper end of the precast column, a superimposed T-beam is arranged on the upper part of the composite steel rib beam, prestressed tendons are arranged inside the superimposed T-beam, and negative moment resisting ribs are fixed at the upper end of the superimposed T-beam by bolts. Prestressed tendons are arranged vertically and horizontally at the connection nodes of the precast column and the superimposed T-beam, and the node connection is completed by post-cast concrete at the beam-column joint.

2. The connection structure according to claim 1, characterized in that: The prefabricated column and the composite steel rib beam are formed in an integrated manner in the PC factory. The composite steel rib beam is composed of an I-shaped steel beam and a supporting panel. The I-shaped steel beam and the supporting panel are an integrated structure and are embedded in the top of the prefabricated column during the production process of the prefabricated column in the PC factory. The width of the flange plate of the I-shaped steel beam is 80mm~100mm, the height of the web is 120mm~160mm, the thickness of the flange and the web is 20mm~35mm, the design width of the supporting panel is equal to the cross-sectional width of the web beam at the lower end of the composite T-beam, the thickness of the supporting panel is 25mm~40mm, the length of the overall composite steel rib beam extending out of the side of the prefabricated column is 550mm~800mm, and the top surface of the composite steel rib beam is flush with the top surface of the prefabricated column concrete; during the integrated forming process of the prefabricated column and the composite steel rib beam in the PC factory, the collision problem between the composite steel rib beam and the designed steel bars on the top of the prefabricated column is solved by reserving holes on the composite steel rib beam.

3. The connection structure according to claim 1, characterized in that: The composite T-beam is prefabricated in the PC factory and consists of a wing beam part and a web beam part. The overall composite T-beam height is not less than 500mm, and the wing beam height of the prefabricated part is not less than 120mm, which does not include the post-casting section. The wing beam width is not less than 600mm, the web beam width is not less than 250mm, and the web beam height is not less than 350mm. Ordinary steel bars and prestressed tendons are provided inside the composite T-beam, and the specific size is determined according to the structural force design.

4. The connection structure according to claim 3, characterized in that: The composite T-beam is placed on the upper part of the composite steel rib beam, and the end of the composite T-beam is placed on the prefabricated column by at least 10mm. The ordinary steel bars extending from the end of the composite T-beam are anchored in the post-cast section at the top of the prefabricated column, and the anchoring length is not less than 450mm. In order to enhance the seismic performance of the beam-column node, each end of the extending ordinary steel bar of the composite T-beam is provided with an anchor plate, and the number is 100%; the lower part of the middle web beam and the end of the wing beam of the composite T-beam are provided with prestressed tendons, and the prestressed tendons can be unbonded prestressed tendons. The unbonded prestressed tendons inside the composite T-beam are designed to be integrally formed during the prefabrication production process of the composite T-beam. The layout of the prestressed tendons shall not collide with the ordinary steel bars inside the composite T-beam. If necessary, BIM technology software shall be used to assist in the design and PC factory component production.

5. The connection structure according to claim 1, characterized in that: In order to improve the negative moment bearing capacity at the beam-column joint, negative moment ribs are provided at the beam-column joint. The negative moment ribs are fixed to the top of the composite T-beam by bolts. The negative moment ribs are located in the composite layer of the composite T-beam. The cutting length of the negative moment ribs shall not be less than the side length of the prefabricated column in the same direction + 2000mm. They are arranged throughout the length. The negative moment ribs are composed of a web and expanded section plates at both ends. The minimum size of the web and the expanded section plates at both ends shall not be less than 12mm, which is determined according to the specific working conditions.

6. The connection structure according to claim 1, characterized in that: Prefabricated columns and their upper integrated composite steel rib beams are divided into beam-column nodes with integrated composite steel rib beams on one side, beam-column nodes with integrated composite steel rib beams on both sides, beam-column nodes with integrated composite steel rib beams on three sides and beam-column nodes with integrated composite steel rib beams on four sides according to the position relationship of the building structure. According to the force characteristics, the structure is designed with double cross nodes, and two types of beam-column node cross design and prestressed cross layout are adopted. The focus is on designing the negative bending moment effect at the beam-column node to improve the seismic performance of the node.

7. The connection structure according to claim 1, characterized in that: In order to strengthen the connection reliability between the composite T-beam and the prefabricated column and improve the efficiency of the lifting and installation of the composite T-beam, bolt holes that are connected to the composite T-beam are provided on the composite steel rib beam. The diameter of the bolt hole is equal to the diameter of the bolt hole reserved inside the composite T-beam and is not less than 20mm.

8. A construction method for an assembled non-bonded prestressed cross beam-column connection structure, characterized in that: The construction process is as follows: PC component production, transportation, and finished product protection---on-site measurement and layout, on-site hoisting of prefabricated columns---combined steel rib beam position verification, sleeve grouting---composite T-beam hoisting, pre-piercing of middle bolts---reinforcement treatment in beam-column nodes, layout of unbonded prestressed tendons---bolt penetration, installation of negative moment ribs---composite slab hoisting, installation of aluminum molds at beam-column nodes---composite slab reinforcement binding, concealed project acceptance---integral pouring of beam, slab, and column concrete, tensioning and anchoring of unbonded prestressed tendons---flow construction, and the above steps are repeated until the entire structural construction is completed.

9. The construction method according to claim 8, characterized in that: The specific technical solutions are as follows: Step S1: PC component production, transportation, and finished product protection Firstly, the precast columns and composite T-beams were designed in depth according to the drawings, and the position relationship between the precast columns and the composite steel rib beams at their upper ends was assisted by BIM technology software. The collision relationship between the internal reinforcement of the precast columns and the composite steel rib beams was checked in particular, and the materials were accurately cut and prefabricated in an integrated manner. During the prefabrication of the composite T-beams, the height of the upper superimposed post-casting of the composite T-beams was ensured, and the reinforcement of the superimposed post-casting section met the reinforcement anchoring and force requirements of the beam-slab nodes. The relationship between the internal prestressed reinforcement holes of the composite T-beams and the designed reinforcement layout of the composite T-beams, as well as the prestressing of the bolt holes inside the composite T-beams, were checked in particular. In principle, ordinary steel bars should avoid prestressed bars without affecting the stress, so as not to affect the construction quality and bearing capacity; after the prefabricated columns, composite T-beams and other components are produced and prefabricated in the PC factory, they can be lifted when the concrete strength reaches more than 85% of the design strength, and can be loaded and transported only when it reaches 100% of the design strength. During transportation, the prefabricated columns and the integrated composite steel rib beams at their upper ends should be protected. The prefabricated components should not be deformed or damaged due to transportation, and the appearance quality problems such as affecting the lifting of the components should not occur, and the finished products should be well protected; Step S2: On-site measurement and layout, on-site hoisting of prefabricated columns After the prefabricated components arrive at the site, we organize special personnel to inspect and accept them. Components with unqualified appearance quality are not allowed to enter the site, and the quality is strictly controlled. After the prefabricated components arrive at the site, we organize the flow construction reasonably according to the on-site measurement schedule, hoist the prefabricated column grid in sections, and mechanically hoist each prefabricated column according to the prefabricated column position line and control line on the top surface of the foundation. Use inclined adjustable steel supports to temporarily fix the prefabricated columns in place, and strictly check the plane position and top elevation of the composite steel rib beam after each prefabricated column is in place. The on-site hoisting of the prefabricated column adopts the "secondary placement" method, that is, the first First, adjust the installation elevation of each prefabricated column according to the elevation of the top surface of the base layer, accurately align the steel sleeve at the bottom of the prefabricated column with the vertical steel bar of the base layer, use the inclined adjustable steel support to initially fix the prefabricated column in place, and then check the top elevation of the composite steel rib beam formed by the prefabricated column one by one, and check the top elevation of each composite steel rib beam one by one, and control the error within 2mm. Finally, adjust the verticality of each prefabricated column, tighten the inclined steel support, and complete the installation of the prefabricated column; do a good job in protecting the composite steel rib beam throughout the process, set up special personnel for inspection and acceptance, and keep acceptance records; Step S3: Check the position of the combined steel rib beam and grout the sleeve The position of the composite steel rib beam directly affects the subsequent hoisting and positioning of the prefabricated composite T-beam. Due to the large volume of the prefabricated composite T-beam, it is difficult to adjust it after it is in place, which directly affects the overall schedule. Therefore, after the prefabricated columns in the construction section are accurately hoisted and positioned, the position relationship and elevation of the composite steel rib beams at each beam-column node are checked and adjusted, and grouting is immediately carried out after confirmation. For beam-column nodes with composite steel rib beams integrated on both sides, beam-column nodes with composite steel rib beams integrated on three sides, and beam-column nodes with composite steel rib beams integrated on four sides, the position relationship and top surface elevation of adjacent composite steel rib beams at the same node should also be checked during the on-site construction process. When the error is large, the position relationship of the prefabricated composite T-beam can be adjusted to integrate the hoisting error of the prefabricated column. The grouting of the steel sleeve at the bottom of the on-site prefabricated column adopts high-strength, low-shrinkage, and micro-expansion grouting material, which is mixed and used at the same time and poured at one time. A dedicated person is stationed on site to ensure the grouting quality of the sleeve at the bottom of each prefabricated column, and to do a good job in the acceptance and record of the hidden project of the steel sleeve grouting. Step S4: Hoisting of the superimposed T-beam and pre-piercing of the middle bolts In order to achieve efficient hoisting of the composite T-beam into place, the composite T-beam can be hoisted after each section of the composite steel rib beam is checked and found to be correct; the bottom of the web beam of the designed composite T-beam is pre-buried with a steel pad during the prefabrication production process of the PC factory. During the on-site hoisting, after the composite T-beam is finally in place, it is necessary to ensure that its end is at least 10mm above the end face of the prefabricated column. After verifying that the plane position and elevation of the composite T-beam are correct, the three-sided full welding method is used to connect and fix the steel pad at the bottom of the composite T-beam to the composite steel rib beam, so as to achieve the effect of no or less support for the lower part of the composite T-beam. The composite T-beam is fixed as soon as it is hoisted into place, which improves the hoisting efficiency and reduces Low construction cost; after the composite T-beam is hoisted in place and fixed, high-strength bolts are used to punch holes from the bottom of the composite steel rib beam, and all the middle bolts on the composite T-beam are inserted in sequence. The high-strength bolts on the composite steel rib beams on each side are designed to be no less than 3, which can improve the shear bearing capacity at the beam-column node. The high-strength bolts within the range of the composite steel rib beams at both ends are first inserted, and then the high-strength bolts in the middle section of the web beam on the composite T-beam are inserted. That is, the two sides are controlled first, and the bolt holes in the middle section of the web beam on the composite T-beam are not subject to hoisting errors. The bolt holes in the middle section of the web beam on the composite T-beam are evenly arranged, with a spacing of no more than 450mm and no less than 5 bolts; Step S5: Steel bar processing in beam-column joints and layout of unbonded prestressed bars After the composite T-beam is hoisted in place, the beam-column node and the upper post-cast section of the composite T-beam can be processed; first, all the ordinary steel bars of the composite T-beam are effectively anchored into the beam-column node, and the anchor length is not less than 35d, d is the diameter of the ordinary steel bars of the composite T-beam, and is not less than 800mm. When the anchor length of the ordinary steel bars cannot meet the design requirements, anchor plates can be set at the ends of the ordinary steel bars; the steel bars in the beam-column node and the upper post-cast section of the composite T-beam should be arranged throughout the length, the diameter of the main force bar should not be less than 30mm, and the requirements for the clear distance of steel bars in the later concrete pouring should be met; for the arrangement requirements of prestressed tendons, while processing the installation of steel bars at the beam-column node, the prestressed tendons inside can be laid simultaneously; the unbonded prestressed tendons are pierced from one end of the composite T-beam to the beam-column node by the traction method, and then pierced from the beam-column node to the other end of the composite T-beam, and arranged crosswise to meet the linear trend of the prestressed tendons, and no fixed support is required, and the concealed project acceptance work is done well; Step S6: Bolt holes and negative moment rib installation After the unbonded prestressed tendons are laid, the high-strength bolts of the wing beam of the composite T-beam can be punched. The high-strength bolts on the wing beams on both sides are arranged in a "staggered wave" style, and are set asymmetrically to enhance the shear resistance of the composite T-beam. Then, the anti-negative bending moment ribs in the upper post-casting section of the composite T-beam are installed, and the installation holes on the anti-negative bending moment ribs are penetrated one by one with high-strength bolts for reliable fixation; at the beam-column node and within 1000mm on both sides, the anti-negative bending moment ribs should be set throughout the length, and incomplete installation phenomena such as splicing and welding of the anti-negative bending moment ribs shall not occur within this range, so as not to affect the overall structural stress performance. There shall be no less than 3 anti-negative bending moment ribs in the same direction, and their installation shall not affect the extension of the steel bars at the top of the prefabricated column and the subsequent concrete pouring process, and the process acceptance and record work shall be done well; Step S7: Hoisting of composite slabs and installation of aluminum formwork at beam-column joints The design adopts the integrated integral superposition cast-in-place forming of beams, plates and columns. On the basis of completing the above-mentioned process, the superimposed plates are hoisted in sections, modules and sections. The ends of the superimposed plates are fixed with high-strength bolts in the upper superimposed layer of the superimposed T-beam or the post-casting section by locally pre-embedded connecting steel plates. The steel bars at the ends of the superimposed plates in other parts extend into the superimposed layer of the superimposed T-beam. Additional steel bars are provided at the junction of the superimposed T-beam and the superimposed plates. The cutting length of the additional steel bars is not less than 1200mm, the diameter is not less than 10mm, and the spacing is not more than 100mm. The additional steel bars are placed on the negative moment ribs in the superimposed layer, and the additional steel bars should be spot welded and fixed to the negative moment ribs one by one. In order to meet the subsequent concrete pouring process, aluminum molds are used for rapid assembly at the beam-column nodes. When the aluminum molds are installed, elastic sealing strips are attached to the contact surfaces with the prefabricated columns and superimposed beams. The aluminum molds are tightened and fixed with the pre-embedded internal threads on the superimposed T-beams and prefabricated columns by screws to achieve the purpose of rapid installation. Step S8: Composite slab reinforcement binding and concealed engineering acceptance According to the construction plan, double-layer bidirectional steel mesh is used for the on-site composite slab hoisting construction. After the composite slab is hoisted into place, after the steel bar connection at the node between the composite slab and the composite T-beam is handled, the upper steel mesh is tied to the upper truss reinforcement of the composite slab. The diameter of the distributed steel bars of the upper steel mesh shall not be less than 10mm, and the spacing of the distributed steel bars shall not exceed 150mm. The distributed steel bars at the composite slab and the composite T-beam shall be laid throughout the length and appropriately dense, with the density spacing not exceeding 100mm. Step S9: Concrete pouring of beams, slabs and columns, tensioning and anchoring of unbonded prestressed tendons After all the above processes are completed and accepted, the concrete of beams, slabs and columns can be poured as a whole. No construction joints shall be left at the beam-column joints. The concrete strength shall not be less than C30. The concrete pouring at the joints between precast columns and composite T-beams, and between composite T-beams and composite slabs shall be strengthened with vibration to ensure the quality of the concrete pouring at the joints. The curing time shall not be less than 7 days. For the tensioning and anchoring of unbonded prestressed tendons on site, the tensioning and anchoring of unbonded prestressed tendons can be carried out only after the construction of all structures of the layer is completed and the concrete strength reaches 100% of the design strength. 1.03σcom over-tensioning and symmetrical tensioning are adopted, and grouting is not required. Both ends of the unbonded prestressed tendons are anchored at the ends or bottom of the superimposed T. A dedicated person is assigned to supervise the process and keep good acceptance records. Step S10: Flow construction, repeating steps 1 to 9 until all structural construction is completed On-site hoisting construction, the hoisting connection of prefabricated columns and composite T-beams has become the focus of the technical solution. The seismic design and construction of beam-column nodes are a significant manifestation of the technical solution's structural innovation and process optimization. For engineering projects with beam-column spans exceeding 12m, special scheme certification should be carried out to ensure the operational safety of the hoisting project. According to the technical solution, a flow construction organization form is adopted, and the above process steps 1 to 9 are repeated until the hoisting construction of the entire structure is completed, and finally the project acceptance and material archiving are carried out.

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