Prefabricated assembly type steel part coated concrete beam-column joint with reinforced beam end and design method of prefabricated assembly type steel part coated concrete beam-column joint

Abstract

The invention discloses a beam end reinforced prefabricated section steel part coated concrete beam-column node, which comprises a section steel part coated concrete column and a section steel part coated concrete beam, and is characterized by further comprising a connecting short beam, two column horizontal stiffening ribs are welded between column flanges, the column horizontal stiffening ribs are parallel to the beam flanges, and the connecting short beam is connected with the section steel part coated concrete column. A plurality of column vertical stiffening ribs are welded between the column horizontal stiffening ribs, a beam end stiffening plate is welded to the side, close to the short beam flange, of the inner side of the beam flange, one side of the short beam flange is welded to the beam flange and the beam end stiffening plate, and the corresponding side of the short beam web is fixedly connected with the beam web through a connecting steel plate. The other side of the short beam flange and the other side of the short beam web in the strong axis direction are welded to the column flange, the other side of the short beam flange in the weak axis direction is welded to the column horizontal stiffening rib, and the other side of the short beam web is welded to the column web. The method has the advantages of capability of improving the shear capacity of a column core area, few on-site connection procedures, simplicity in construction, short construction period and convenience in transportation.

Description

Technical Field

[0001] The invention relates to a steel-partially-covered concrete composite structure, in particular to a prefabricated assembled steel-partially-covered concrete beam-column node with reinforced beam ends and a design method thereof. Background Art

[0002] The steel partially encased concrete composite structure is a composite structure in which transverse ties are welded between the flanges of H-shaped steel and filled with concrete. It can be widely used in multi-story structures such as residential and office buildings. Steel partially encased concrete beams, columns and other components can be prefabricated in factories or on site. The hoisting and connection methods of the components are similar to those of steel components, so a high level of prefabrication and assembly can be achieved. The difficulty in the design and construction of steel partially encased concrete beam-column nodes lies in the connection method of the beam end nodes at the connection between the steel partially encased concrete columns and the steel partially encased concrete beams.

[0003] At present, the connection between the steel-section partially covered concrete beam and column is a hinged node or a rigid node connected by bolts and welds to meet the node performance requirements. Then, it is necessary to weld steel bars, support formwork, pour concrete, and remove formwork in the beam end connection node. Figure 1 As shown in the figure, the following problems exist in the construction site using cast-in-place connection: (1) It is extremely inconvenient to tie and weld the steel bars and support the formwork at the construction site, which makes the on-site connection process more complicated and greatly prolongs the construction period; (2) During the pouring process, it is easy to find that the grouting is not full after the formwork is removed. At the same time, in order to solve the grouting problem, the chamfer is cast at the beam end node, but the chamfer affects the appearance and needs to be removed in the later stage of construction, which seriously wastes manpower and material resources. At the same time, the steel-coated concrete column of the steel-coated concrete beam-column connection node in the weak axis direction is easily affected by shear stress, resulting in concrete damage in the core area. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a prefabricated assembled steel partially covered concrete beam-column node structure and design method which can improve the shear resistance of the core area of ​​the column and has the advantages of fewer on-site connection processes, simple construction, short construction period and convenient transportation, and reinforced beam ends.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a prefabricated assembled steel-partially covered concrete beam-column node with reinforced beam ends, comprising a steel-partially covered concrete column and at least one steel-partially covered concrete beam, wherein the steel-partially covered concrete column comprises a column flange and a column web welded between the column flanges, and the steel-partially covered concrete beam comprises a beam flange and a beam web welded between the beam flanges, and also comprises a connecting short beam for connecting the steel-partially covered concrete column and the steel-partially covered concrete beam, wherein the connecting short beam comprises a short beam flange and a short beam web welded between the short beam flanges, and a short beam web welded between the column flanges to connect the column web. Two column horizontal stiffening ribs are perpendicular to the plates, the column horizontal stiffening ribs are parallel to the beam flanges, a number of column vertical stiffening ribs are welded between the column horizontal stiffening ribs, a beam end stiffening plate is welded on the inner side of the beam flange and close to the short beam flange side, one side of the short beam flange is respectively welded to the beam flange and the beam end stiffening plate, and the corresponding side of the short beam web is fixedly connected to the beam web through a connecting steel plate, the short beam flange and the other side of the short beam web in the strong axis direction are respectively welded to the column flange, and the other side of the short beam flange in the weak axis direction is welded to the column horizontal stiffening rib and the other side of the short beam web is welded to the column web.

[0006] Furthermore, column body concrete is poured on both sides of the column web in the main steel component of the concrete column partially covered by the steel section.

[0007] Furthermore, a beam partition is provided between the beam flanges and near the connecting steel plate, the steel section partially covers the concrete beam and beam body concrete is poured on both sides of the beam web in the main steel member located outside the beam partition.

[0008] Furthermore, the short beam web and the beam web are respectively fastened to the connecting steel plate by bolts.

[0009] The present invention also provides a construction method for the above-mentioned beam end reinforced prefabricated assembled steel partially covered with concrete beam-column node structure, the steps are as follows:

[0010] (1) The main steel components of the concrete columns are partially covered with prefabricated steel sections processed in the factory;

[0011] (2) The main steel components of the concrete beams are partially covered with prefabricated steel sections processed in the factory;

[0012] (3) The factory-processed prefabricated connecting short beams include short beam flanges and short beam webs. The short beam flanges and the outer side of the column flanges in the strong axis direction are fully penetrated by welding, and the short beam webs are fully penetrated by welding on the outer side of the column flanges. In the weak axis direction, the short beam flanges and the horizontal stiffening ribs of the columns are fully penetrated by welding, and the short beam webs are fully penetrated by welding with the column webs.

[0013] (4) The factory ties and welds the main steel components of the steel and steel-wrapped concrete columns and steel-wrapped concrete beams;

[0014] (5) The factory welds the beam end stiffener plate to the inside of the beam flange near the end of the connecting short beam;

[0015] (6) Factory cast concrete for the column with partially enclosed steel concrete and concrete for the beam with partially enclosed steel concrete;

[0016] (7) Transport the steel partially covered concrete columns, steel partially covered concrete beams, connecting steel plates and high-strength friction bolts to the site;

[0017] (8) The construction is completed by connecting the steel-partially-covered concrete column and the steel-partially-covered concrete beam by bolt welding through the connecting short beam.

[0018] Furthermore, step (8) is specifically as follows: the beam web and the short beam web are connected via the connecting steel plate and the high-strength friction bolts, and the beam flange and the beam end stiffener are respectively connected to the short beam flange by full penetration welding.

[0019] The present invention also provides a design method for the above-mentioned beam-column node structure with prefabricated assembled steel parts covered with concrete at the beam end reinforcement, the steps are as follows:

[0020] Step 1: Determine the thickness t of the beam end stiffener s ;

[0021] Step 2: Determine the width b of the beam end stiffener s ;

[0022] Step 3: Determine the length and thickness of the short beam flange connecting the short beams;

[0023] Step 4: Determine the number of shear bolts n1;

[0024] Step 5: Determine the bending bearing capacity of the steel-partially-enclosed concrete beam-column joint and the steel-partially-enclosed concrete beam;

[0025] Step 6: Determine the positions of column horizontal stiffeners, column vertical stiffeners and beam partitions.

[0026] Further, the specific steps are as follows:

[0027] Step 1: Determine the thickness t of the beam end stiffener s , the calculation formula is as follows:

[0028] In the formula, I s is the moment of inertia of the stiffener sections at the four beam ends; b f is the width of the beam flange; t f is the thickness of the beam flange 21; t s is the thickness of the beam end stiffener; h w is the effective height of the section of the concrete beam partially covered by the steel section;

[0029] Step 2: Determine the width b of the beam end stiffener s , the calculation formula is as follows:

[0030] Where b f is the width of the beam flange, t w is the thickness of the beam web;

[0031] Step 3: Determine the length and thickness of the short beam flange of the connecting short beam, as follows: The length of the connecting short beam is the height h of the steel-covered concrete beam b 1 / 2 to 2 / 3 of the beam flange thickness. At the same time, the thickness of the short beam flange is the sum of the thickness of the beam flange and the beam end stiffener. The thickness of the short beam web is equal to the thickness of the beam web.

[0032] Step 4: Determine the number of shear bolts n1, the calculation formula is as follows:

[0033] Among them, n f is the number of friction surfaces that transmit the load; and P are the shear bearing capacity and design pretension value of a single high-strength bolt respectively; μ is the friction coefficient of the friction surface; F p is the ultimate shear bearing capacity borne by the beam end;

[0034] Step 5: Determine the bending bearing capacity of the steel-partially-enclosed concrete beam-column joint and the steel-partially-enclosed concrete beam;

[0035] (1) Yield moment M of the steel-enclosed concrete beam-column joint y1 and the ultimate bending moment M p1 The calculation formula is as follows:

[0036] M y1 =W n f a , M p1 =η j W n f a , where W n =I n / (0.5h b ), Where W n It is the net section modulus of the unfilled concrete part of the steel-enclosed concrete beam after deducting the web bolt holes; n I is the net section inertia of the unfilled concrete portion of the steel-enclosed concrete beam after deducting the web bolt holes; a is the gross section moment of inertia of the main steel component of the steel-enclosed concrete beam without concrete filling; η j is the connection coefficient, f a h is the design value of the tensile strength of the main steel component of the steel-covered concrete beam without concrete filling; b is the section height of the concrete beam partially covered by the steel section; I s is the moment of inertia of the stiffener sections at the four beam ends; t w is the thickness of the beam web; d w is the diameter of the high-strength bolt holes in the web of the beam; i It is the distance from the neutral axis of the section of the unfilled concrete part of the steel-partially covered concrete beam to the center of the high-strength bolt hole in its web;

[0037] (2) Yield moment M of the steel-partially covered concrete beam y2 and the ultimate bending moment M p2 The calculation formula is as follows:

[0038]

[0039] Where a1 is the influence coefficient of concrete compressive stress in the compression zone. When the concrete strength grade does not exceed C50, a1 is 1.0. When the concrete strength grade is C80, a1 is 0.94. The linear interpolation method is used in between. x is the height of the concrete section in the compression zone of the beam flange. f cw is the design value of concrete axial compressive strength; b f is the width of the beam flange; t w is the thickness of the beam web; h b is the cross-sectional height of the steel-enclosed concrete beam; t f is the thickness of the beam flange; a s f is the distance from the combined force point of the steel bars in the tension zone to the tensile edge of the concrete; y is the design value of the tensile strength of the steel bar; f a 、f' a A is the design value of tensile and compressive strength of the main steel component of the steel-covered concrete beam without concrete filling; s is the cross-sectional area of ​​the longitudinal tensile reinforcement; S at , S acThey are the tensile and compressive areas of the main steel member section of the concrete beam partially covered by the steel section, and the area moment of the main steel member section of the beam to the plastic neutral axis of the composite section; η j is the connection coefficient;

[0040] Step 6: Determine the positions of column horizontal stiffeners, column vertical stiffeners and beam diaphragms as follows:

[0041] (1) The horizontal stiffening ribs of the column are set perpendicular to the column flange, and the thickness of the horizontal stiffening ribs of the column is set equal to the thickness of the short beam flange;

[0042] (2) The column vertical stiffening ribs are arranged perpendicularly to the column horizontal stiffening ribs, the thickness of the column vertical stiffening ribs is set equal to the thickness of the column flange, and the spacing of the column vertical stiffening ribs is set equal to the width of the beam flange;

[0043] (3) The beam partition is set perpendicular to the beam flange, and the thickness of the beam partition is set to be equal to the thickness of the beam web.

[0044] Compared with the prior art, the advantages of the present invention are

[0045] (1) The steel partially covered concrete columns, steel partially covered concrete beams, connecting steel plates and other node accessories of the prefabricated assembled steel partially covered concrete beam-column node for beam end reinforcement of the present invention can be prefabricated in the factory, which can avoid the wet operation of steel bar welding and concrete pouring on site; the prefabricated steel partially covered concrete columns and steel partially covered concrete beams are transported to the site for hoisting and installation, and the connecting short beams are bolted and welded to the steel partially covered concrete beams, which reduces the construction process and can keep pace with the construction progress of the assembled steel structure;

[0046] (2) The prefabricated assembled steel-partially covered concrete beam-column node with reinforced beam ends of the present invention has additional column vertical stiffening ribs between the column horizontal stiffening ribs in the core area of ​​the steel-partially covered concrete column, thereby enhancing the shear strength of the core area of ​​the steel-partially covered concrete column in the weak axis direction, ensuring the structural seismic design goal of strong columns and weak beams. At the same time, the addition of the stiffening plate at the beam end ensures that the strength and stiffness of the stiffening plate steel-partially covered concrete beam-column beam end connection node are not lower than the strength and stiffness of the original cast concrete node, and can meet the structural seismic design goal of strong nodes and weak components;

[0047] (3) The construction of the prefabricated assembled steel partially covered concrete beam-column node with reinforced beam ends of the present invention is achieved by welding a beam end stiffening plate on the side of the steel partially covered concrete beam close to the steel partially covered concrete column, so that the beam end in the node area reaches the same stiffness as the cross-section of the steel partially covered concrete beam, which brings great convenience to the on-site construction and can also fully guarantee the quality of the core area of ​​the node; the stiffening plate steel partially covered concrete beam-column connection node eliminates the processes of steel bar welding, formwork support, and concrete pouring in the steel partially covered concrete beam-column node area during on-site lifting and installation, reduces on-site wet operations, and speeds up the on-site steel structure installation progress. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 Construction drawings of partially covered concrete beam-column joints in the field;

[0049] Figure 2 A three-dimensional diagram of a concrete beam-column connection node structure partially covered with a stiffened plate steel according to the present invention;

[0050] Figure 3 A three-dimensional scattered diagram of a concrete beam-column connection node structure partially covered with a stiffened plate steel according to the present invention;

[0051] Figure 4 It is a cross-sectional view of a concrete beam-column connection node structure partially covered with a stiffened plate steel according to the present invention;

[0052] Figure 5 for Figure 3 The cross-section along AA (the direction of the strong axis of the column);

[0053] Figure 6 for Figure 3 The cross-section along BB (column weak axis direction);

[0054] Figure 7 is the concrete height diagram of the compression zone;

[0055] Figure 8 The concrete between the flanges of the node beam is converted into a steel section;

[0056] Fig. 9 The concrete in the compression zone between the flanges of the node beam is converted to steel section diagram;

[0057] Fig.10 This is the calculation diagram of the thickness and width of the beam end stiffener;

[0058] Fig.11 A cross-sectional view of the beam-column connection node with a partially covered concrete stiffening plate steel connection;

[0059] Fig.12 Schematic diagram of the cross section of a partially encased concrete beam and the stress under positive bending moment.

[0060] The markings in the figure are as follows: 1-connecting short beam, 2-short beam flange, 3-short beam web, 4-connecting steel plate, 5-beam end stiffener, 6-bolt, 7-rebar;

[0061] 10- steel partially covered concrete column, 11- column flange, 12- column web, 13- column horizontal stiffening rib, 14- column vertical stiffening rib, 15- column shaft concrete;

[0062] 20- steel-partially-covered concrete beam, 21- beam flange, 22- beam web, 23- beam body concrete, 24- beam diaphragm. DETAILED DESCRIPTION

[0063] The present invention is further described in detail below with reference to the accompanying drawings.

[0064] Specific embodiment 1: The prefabricated assembled steel parts with reinforcement at the beam ends partially cover the concrete beam-column node structure.

[0065] like Figure 2 As shown, a prefabricated assembled steel partially covered concrete beam-column node with reinforced beam ends includes a steel partially covered concrete column 10 and two steel partially covered concrete beams 20, one steel partially covered concrete beam 20 is connected to the steel partially covered concrete column 10 in the strong axis direction by connecting a short beam 1, and the other steel partially covered concrete beam 20 is connected to the steel partially covered concrete column 10 in the weak axis direction by connecting the short beam 1.

[0066] like Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the main steel component of the steel-partially-enclosed concrete column 10 includes a column flange 11 and a column web 12, and its cross section is H-shaped. The core area of ​​the steel-partially-enclosed concrete column 10 is provided with a column horizontal stiffening rib 13 and a column vertical stiffening rib 14. The column horizontal stiffening rib 13 is welded between the column flanges 11 and is parallel to the beam flange 21. The column vertical stiffening rib 14 is welded between the column horizontal stiffening ribs 13. The vertical stiffening rib 14 enhances the shear strength of the core area of ​​the steel-partially-enclosed concrete column 10 in the weak axis direction, ensuring the structural seismic design goal of strong column and weak beam. The column body concrete 15 is poured on both sides of the column web 12 in the main steel component of the steel-partially-enclosed concrete column 10.

[0067] In this specific embodiment, the main steel component of the steel-partially-enclosed concrete beam 20 includes a beam flange 21 and a beam web 22, and its cross section is H-shaped. A beam partition 24 is fully penetrated and welded between the beam flanges 21 and close to the connecting short beam 1. The side of the beam partition 24 close to the steel-partially-enclosed concrete column 10 is not filled with concrete, which facilitates the connection between the steel-partially-enclosed concrete beam 20 and the connecting short beam 1. The beam body concrete 23 is poured on both sides of the beam web 22 in the main steel component of the steel-partially-enclosed concrete beam 20. A beam end stiffener 5 is fully penetrated and welded on the inner side of the beam flange 21 and close to the connecting short beam 1. In this embodiment, the beam end stiffener 5 is used to enhance the bending strength and rigidity of the beam end connection node, so that the strength and rigidity of the beam end connection node are not less than the strength and rigidity of the cross section of the steel-partially-enclosed concrete beam 20.

[0068] In this specific embodiment, the connecting short beam 1 includes a short beam flange 2 and a short beam web 3, and its cross section is H-shaped. One side of the short beam flange 2 is welded with the beam flange 21 and the beam end stiffener 5 by a cutout full penetration. In the strong axis direction, the other side of the short beam flange 2 is welded with a cutout full penetration on the outside of the column flange 11, and the short beam web 3 is welded with a cutout full penetration on the outside of the column flange 11. In the weak axis direction, the short beam flange 2 is welded with the column horizontal stiffening rib 11 by a cutout full penetration, and the short beam web 3 is welded with the column web 12 by a cutout full penetration. The short beam web 3 is fixedly connected to the beam web 22 by a connecting steel plate 4, and the short beam web 3 and the beam web 22 are fastened to the connecting steel plate 4 by high-strength friction bolts 6, respectively.

[0069] Specific embodiment 2: The construction method of the concrete beam-column node structure partially covered with prefabricated assembled steel with reinforced beam ends in specific embodiment 1, the steps are as follows:

[0070] (1) The main steel components of the concrete column 10 are partially covered with prefabricated steel sections processed in the factory, including the column horizontal stiffening ribs 13 and the column vertical stiffening ribs 14;

[0071] (2) The main steel components of the concrete beam 20 are partially covered with prefabricated steel sections processed in the factory, including the beam diaphragm 24;

[0072] (3) The factory processes and prefabricates the connecting short beam 1, which includes the short beam flange 2 and the short beam web 3. The short beam flange 2 and the outer side of the column flange 11 are fully penetrated and welded in the strong axis direction, and the short beam web 3 is fully penetrated and welded in the outer side of the column flange 11. In the weak axis direction, the short beam flange 2 and the column horizontal stiffener 11 are fully penetrated and welded in the split, and the short beam web 3 and the column web 12 are fully penetrated and welded;

[0073] (4) The factory ties and welds the steel bars 7 to the main steel components of the steel-partially-covered concrete column 10 and the steel-partially-covered concrete beam 20;

[0074] (5) The factory welds the beam end stiffener 5 to the inner side of the beam flange 21 near one end of the connecting short beam 1;

[0075] (6) Casting the column concrete 15 of the steel-partially-encased concrete column 10 and the beam concrete 23 of the steel-partially-encased concrete beam 20 in the factory;

[0076] (7) transporting the steel partially covered concrete column 10, the steel partially covered concrete beam 20, the connecting steel plate 4 and the high-strength friction bolts 6 to the site;

[0077] (8) The steel-partially-covered concrete column 10 and the steel-partially-covered concrete beam 20 are connected by bolt welding through the connecting short beam 1 (such as Figure 4 , 5 As shown), specifically as follows: the beam web 22 is connected to the short beam web 3 by connecting steel plates 4 and high-strength friction bolts 6, and the beam flange 21 and the beam end stiffener 5 are respectively connected to the short beam flange 2 by full penetration welding.

[0078] Specific embodiment 3, a design method for a prefabricated assembled steel partly covered concrete beam-column node structure with reinforced beam ends, comprising the following steps:

[0079] Step 1: The seismic performance and design of the beam flange connection mainly depends on the bending bearing capacity of the beam, as shown in the attached figure. Figure 7-10 As shown, when designing the thickness ts of the beam end stiffener 5, the stiffness conversion thickness is calculated according to the bending stiffness to determine the thickness ts of the beam end stiffener 5, as follows:

[0080] When the steel-wrapped concrete beam 20 section is at the ultimate normal section bearing capacity, as shown in the attached Figure 7 As shown in the figure, the concrete section height x in the compression zone of the beam flange 21 is calculated according to formula (1): a1f cw (b f -t w )x+f a 'A ac +f y 'A s ′=f a A at +f y A s (1), where a1 is the influence coefficient of concrete compressive stress in the compression zone. When the concrete strength grade does not exceed C50, a1 is 1.0; when the concrete strength grade is C80, a1 is 0.94. The intermediate values ​​are determined by linear interpolation. cw is the design value of concrete axial compressive strength; b f is the width of the beam flange 21; t w is the thickness of the beam web 22; f y 、f'y are the design values ​​of tensile and compressive strength of steel bars; f a 、f' a A is the design value of tensile and compressive strength of the main steel component of the steel-wrapped concrete beam 20; s , A' s are the cross-sectional areas of longitudinal tensile and compressive reinforcements respectively; A at , A ac They are respectively the cross-sectional areas of the tensile and compressive zones of the main steel member of the steel-partially-wrapped concrete beam 20.

[0081] As attached Figure 8 , Fig. 9 As shown, the equivalent moment of inertia of the section I taking into account the effect of cracking of tensile concrete eq According to formula (2-4), we can obtain:

[0082] I eq =(I ucr +I cr ) / 2(2), where I ucr =I a,ucr +I c,ucr (3), I cr =I a,cr +I c,cr (4);

[0083] In the formula, I ucr is the converted section moment of inertia of the uncracked section of the steel-partially covered concrete beam 20 (Appendix Figure 8 ), I cr is the converted section moment of inertia of the cracked section of the steel-partially covered concrete beam 20 (Appendix Fig. 9 );I a,ucr ,I c,ucr They are the moment of inertia of the main steel component of the beam 20 partially covered with concrete and the converted moment of inertia of the steel section after the concrete section between the beam flange 21 is converted. a,cr ,I c,cr They are respectively the moment of inertia of the main steel component of the steel-partially-wrapped concrete beam 20 and the converted moment of inertia of the steel section after the concrete section of the compression zone between the beam flanges 21 is converted.

[0084] As attached Fig.10 As shown, the moment of inertia of the node I es According to formula (5-6), we can obtain:

[0085] I es =I a +I s =I eq (5), where

[0086] In the formula, I ais the moment of inertia of the section of the main steel member of the steel-enclosed concrete beam 20; s is the moment of inertia of the cross section of the four beam end stiffeners; b f is the width of the beam flange 21; t f is the thickness of the beam flange 21; t s is the thickness of the beam end stiffener 5; h b h is the height of the section of the steel section covering the concrete beam 20; w is the effective height of the section of the concrete beam 20 covered by the steel section. Finally, the thickness t of the beam end stiffener 5 is calculated by equations (1)-(6): s .

[0087] Step 2: Determine the width b of the beam end stiffener 5 s ;

[0088] Where b f is the width of the beam flange 21; t w is the thickness of the beam web 22 .

[0089] Step 3: Determine the length and thickness of the short beam flange 2 connected to the short beam 1 as follows:

[0090] The length of the connecting short beam 1 is the height h of the steel-wrapped concrete beam 20 b 1 / 2 to 2 / 3 of the thickness of the short beam flange 2, and the thickness of the short beam flange 2 is the sum of the thickness of the beam flange 21 and the beam end stiffener 5, and the thickness of the short beam web 3 is equal to the thickness of the beam web 22;

[0091] Step 4: Determine the number of shear bolts 6;

[0092] The number n1 of shear bolts 6 is calculated according to formula (8): Among them, n f is the number of friction surfaces that transmit the load; and P are the shear bearing capacity and design pretension value of a single high-strength bolt respectively; μ is the friction coefficient of the friction surface; F p It is the ultimate shear bearing capacity borne by the beam end, refer to Code for Design of Steel Structures (GB50017-2017).

[0093] Step 5: Determine the bending bearing capacity of the steel-partially-covered concrete beam-column node and the steel-partially-covered concrete beam 20;

[0094] like Fig.11 As shown in the figure, the yield moment M of the steel-enclosed concrete beam-column joint y1 and the ultimate bending moment M p1 According to formula (9-12), we can obtain: M y1 =W n f a(9), M p1 =η j W n f a (10), where W n =I n / (0.5h b )(11), Where W n is the net section modulus of the unfilled concrete portion of the steel-covered concrete beam 20 after deducting the web bolt holes; n I is the net section inertia moment of the unfilled concrete portion of the steel-covered concrete beam 20 after deducting the web bolt holes; a is the gross section moment of inertia of the main steel member of the steel-part-covered concrete beam 20 not filled with concrete; η j is the connection coefficient. a h is the design value of the tensile strength of the main steel component of the steel-covered concrete beam 20 that is not filled with concrete; b is the cross-sectional height of the steel-covered concrete beam 20; s is the moment of inertia of the cross section of the four beam end stiffeners; t w is the thickness of the beam web 22; d w is the diameter of the high-strength bolt holes in the beam web 22; i It is the distance from the neutral axis of the section of the unfilled concrete portion of the steel-partially-covered concrete beam 20 to the center of the high-strength bolt hole in its web.

[0095] like Fig.12 As shown, the yield moment M of the steel-partially covered concrete beam 20 is y2 and the ultimate bending moment M p2 According to formula (13-14), we can obtain:

[0096]

[0097] Where a1 is the influence coefficient of concrete compressive stress in the compression zone. When the concrete strength grade does not exceed C50, a1 is 1.0. When the concrete strength grade is C80, a1 is 0.94. The intermediate values ​​are determined by linear interpolation. x is the height of the concrete section in the compression zone within the beam flange 21. f cw is the design value of concrete axial compressive strength; b f is the width of the beam flange 21; t w is the thickness of the beam web 22; h b is the cross-sectional height of the steel-enclosed concrete beam 20; t f is the thickness of the beam flange 21; a s f is the distance from the combined force point of the steel bars in the tension zone to the tensile edge of the concrete; y is the design value of the tensile strength of the steel bar; f a、f' a A is the design value of tensile and compressive strength of the main steel component of the steel-covered concrete beam 20 without concrete filling; s is the cross-sectional area of ​​the longitudinal tensile reinforcement; S at , S ac They are respectively the tensile and compressive areas of the main steel member section of the steel-wrapped concrete beam 20, and the area moment of the main steel member section of the beam to the plastic neutral axis of the composite section; η j is the connection coefficient.

[0098] Step 6: Determine the positions of the column horizontal stiffener 13, the column vertical stiffener 14 and the beam diaphragm 24, as follows:

[0099] (1) The column horizontal stiffening rib 13 is vertically arranged with the column flange 11, and the thickness of the column horizontal stiffening rib 13 is set equal to the thickness of the short beam flange 2;

[0100] (2) The width of the column vertical stiffening rib 14 is set perpendicular to the column horizontal stiffening rib 13, the thickness of the column vertical stiffening rib 14 is set equal to the thickness of the column flange 11, and the spacing of the column vertical stiffening rib 14 is set equal to the width of the beam flange 21;

[0101] (3) The beam diaphragm 24 is vertically arranged with the beam flange 21 , and the thickness of the beam diaphragm 24 is set equal to the thickness of the beam web 22 , and no concrete is filled between the beam diaphragm 24 and the steel-partially-covered concrete column 10 .

[0102] The above description is not intended to limit the present invention, and the present invention is not limited to the above examples. Any changes, modifications, additions or substitutions made by a person skilled in the art within the spirit and scope of the present invention shall also fall within the protection scope of the present invention.

Claims

1. A prefabricated steel-partially-enclosed concrete beam-column node with reinforced beam ends, comprising a steel-partially-enclosed concrete column and at least one steel-partially-enclosed concrete beam, wherein the steel-partially-enclosed concrete column comprises a column flange and a column web welded between the column flanges, and the steel-partially-enclosed concrete beam comprises a beam flange and a beam web welded between the beam flanges, characterized in that: The invention also includes a connecting short beam for connecting the steel-partially covered concrete column and the steel-partially covered concrete beam, the connecting short beam including a short beam flange and a short beam web welded between the short beam flanges, two column horizontal stiffening ribs perpendicular to the column web are welded between the column flanges, the column horizontal stiffening ribs are parallel to the beam flanges, a plurality of column vertical stiffening ribs are welded between the column horizontal stiffening ribs, a beam end stiffening plate is welded on the inner side of the beam flange and close to the short beam flange side, one side of the short beam flange is respectively welded to the beam flange and the beam end stiffening plate, and the corresponding side of the short beam web is fixedly connected to the beam web through a connecting steel plate, the short beam flange and the other side of the short beam web in the strong axis direction are respectively welded to the column flange, the other side of the short beam flange in the weak axis direction is welded to the column horizontal stiffening rib and the other side of the short beam web is welded to the column web.

2. The prefabricated assembled steel part-wrapped concrete beam-column node with beam end reinforcement according to claim 1, characterized in that: Column body concrete is poured on both sides of the column web in the main steel component of the concrete column covered with the steel section.

3. The prefabricated assembled steel part-wrapped concrete beam-column node with beam end reinforcement according to claim 1, characterized in that: A beam partition is arranged between the beam flanges and near the connecting steel plate, the profiled steel partially covers the concrete beam and beam body concrete is poured on both sides of the beam web in the main steel member located outside the beam partition.

4. The prefabricated assembled steel part-wrapped concrete beam-column node with beam end reinforcement according to claim 1, characterized in that: The short beam web and the beam web are respectively fastened and connected to the connecting steel plate by bolts.

5. A construction method for a beam-column node structure with a prefabricated assembled steel partly covered with concrete for beam end reinforcement according to any one of claims 1 to 4, characterized in that Here are the steps: (1) The main steel components of the concrete columns are partially covered with prefabricated steel sections processed in the factory; (2) The main steel components of the concrete beams are partially covered with prefabricated steel sections processed in the factory; (3) The factory-processed prefabricated connecting short beams include short beam flanges and short beam webs. The short beam flanges and the outer side of the column flanges in the strong axis direction are fully penetrated by welding, and the short beam webs are fully penetrated by welding on the outer side of the column flanges. In the weak axis direction, the short beam flanges and the horizontal stiffening ribs of the columns are fully penetrated by welding, and the short beam webs are fully penetrated by welding with the column webs. (4) The factory ties and welds the main steel components of the steel and steel-wrapped concrete columns and steel-wrapped concrete beams; (5) The factory welds the beam end stiffener plate to the inside of the beam flange near the end of the connecting short beam; (6) Factory cast concrete for the column with partially enclosed steel concrete and concrete for the beam with partially enclosed steel concrete; (7) Transport the steel partially covered concrete columns, steel partially covered concrete beams, connecting steel plates and high-strength friction bolts to the site; (8) The construction is completed by connecting the steel-partially-covered concrete column and the steel-partially-covered concrete beam by bolt welding through the connecting short beam.

6. The construction method of the beam-column node structure with prefabricated assembled steel parts covered with concrete for beam end reinforcement according to claim 5 is characterized in that Step (8) is specifically as follows: the beam web and the short beam web are connected via the connecting steel plate and the high-strength friction bolts, and the beam flange and the beam end stiffener are respectively connected to the short beam flange by full penetration welding.

7. A design method for a beam-column node structure with a prefabricated assembled steel partly covered with concrete with beam end reinforcement according to any one of claims 1 to 4, characterized in that Here are the steps: Step 1: Determine the thickness t of the beam end stiffener s ; Step 2: Determine the width b of the beam end stiffener s ; Step 3: Determine the length and thickness of the short beam flange connecting the short beams; Step 4: Determine the number of shear bolts n1; Step 5: Determine the bending bearing capacity of the steel-partially-enclosed concrete beam-column joint and the steel-partially-enclosed concrete beam; Step 6: Determine the positions of column horizontal stiffeners, column vertical stiffeners and beam partitions.

8. The design method of the beam-column node structure with prefabricated assembled steel parts covered with concrete with beam end reinforcement according to claim 7 is characterized in that The specific steps are as follows: Step 1: Determine the thickness t of the beam end stiffener s , the calculation formula is as follows: In the formula, I s is the moment of inertia of the stiffener sections at the four beam ends; b f is the width of the beam flange; t f is the thickness of the beam flange 21; t s is the thickness of the beam end stiffener; h w is the effective height of the section of the concrete beam partially covered by the steel section; Step 2: Determine the width b of the beam end stiffener s , the calculation formula is as follows: Where b f is the width of the beam flange, t w is the thickness of the beam web; Step 3: Determine the length and thickness of the short beam flange of the connecting short beam, as follows: The length of the connecting short beam is the height h of the steel-covered concrete beam b 1 / 2 to 2 / 3 of the beam flange thickness. At the same time, the thickness of the short beam flange is the sum of the thickness of the beam flange and the beam end stiffener. The thickness of the short beam web is equal to the thickness of the beam web. Step 4: Determine the number of shear bolts n1, the calculation formula is as follows: Among them, n f is the number of friction surfaces that transmit the load; and P are the shear bearing capacity and design pretension value of a single high-strength bolt respectively; μ is the friction coefficient of the friction surface; F p is the ultimate shear bearing capacity borne by the beam end; Step 5: Determine the bending bearing capacity of the steel-partially-enclosed concrete beam-column joint and the steel-partially-enclosed concrete beam; (1) Yield moment M of the steel-enclosed concrete beam-column joint y1 and the ultimate bending moment M p1 The calculation formula is as follows: y1 =W n f a , M p1 =η j W n f a , where W n =I n / (0.5h b ), Where W n It is the net section modulus of the unfilled concrete part of the steel-enclosed concrete beam after deducting the web bolt holes; n I is the net section inertia of the unfilled concrete portion of the steel-enclosed concrete beam after deducting the web bolt holes; a is the gross section moment of inertia of the main steel component of the steel-enclosed concrete beam without concrete filling; η j is the connection coefficient, f a h is the design value of the tensile strength of the main steel component of the steel-covered concrete beam without concrete filling; b is the section height of the concrete beam partially covered by the steel section; I s is the moment of inertia of the stiffener sections at the four beam ends; t w is the thickness of the beam web; d w is the diameter of the high-strength bolt holes in the web of the beam; i It is the distance from the neutral axis of the section of the unfilled concrete part of the steel-partially covered concrete beam to the center of the high-strength bolt hole in its web; (2) Yield moment M of the steel-partially covered concrete beam y2 and the ultimate bending moment M p2 The calculation formula is as follows: Where a1 is the influence coefficient of concrete compressive stress in the compression zone. When the concrete strength grade does not exceed C50, a1 is 1.

0. When the concrete strength grade is C80, a1 is 0.

94. The linear interpolation method is used in between. x is the height of the concrete section in the compression zone of the beam flange. f cw is the design value of concrete axial compressive strength; b f is the width of the beam flange; t w is the thickness of the beam web; h b is the cross-sectional height of the steel-enclosed concrete beam; t f is the thickness of the beam flange; a s f is the distance from the combined force point of the steel bars in the tension zone to the tensile edge of the concrete; y is the design value of the tensile strength of the steel bar; f a 、f' a A is the design value of tensile and compressive strength of the main steel component of the steel-covered concrete beam without concrete filling; s is the cross-sectional area of ​​the longitudinal tensile reinforcement; S at , S ac They are the tensile and compressive areas of the main steel member section of the concrete beam partially covered by the steel section, and the area moment of the main steel member section of the beam to the plastic neutral axis of the composite section; η j is the connection coefficient; Step 6: Determine the positions of column horizontal stiffeners, column vertical stiffeners and beam diaphragms as follows: (1) The horizontal stiffening ribs of the column are set perpendicular to the column flange, and the thickness of the horizontal stiffening ribs of the column is set equal to the thickness of the short beam flange; (2) The column vertical stiffening ribs are arranged perpendicularly to the column horizontal stiffening ribs, the thickness of the column vertical stiffening ribs is set equal to the thickness of the column flange, and the spacing of the column vertical stiffening ribs is set equal to the width of the beam flange; (3) The beam partition is set perpendicular to the beam flange, and the thickness of the beam partition is set to be equal to the thickness of the beam web.

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