Connection structure and construction method for assembled box-shaped UHPC compression members

Abstract

The present invention discloses a connection structure for assembled box-shaped UHPC compression members, comprising a pair of adjacently arranged box-shaped UHPC compression members and a pair of steel box beam joints arranged between the adjacent box-shaped UHPC compression members, wherein the pair of steel box beam joints are respectively connected to the pair of box-shaped UHPC compression members; one end of the steel box beam joint is pre-embedded and fitted in the inner cavity of the box-shaped UHPC compression member, and the other end extends to the outside of the box-shaped UHPC compression member to form an extended section, and the end of the extended section is provided with a connecting surface, and a plurality of through holes are opened on the connecting surface; the adjacent connecting surfaces are fitted, and the through holes on the adjacent connecting surfaces correspond to each other one by one, and the adjacent connecting surfaces are connected by a connecting assembly arranged in the through hole. The present invention also provides a construction method for the above-mentioned connection structure. The assembled box-shaped UHPC compression member of the present invention has the advantages of simple structure, safety and reliability, high construction efficiency, and low construction cost.

Description

Technical Field

[0001] The invention belongs to the field of bridge engineering, and in particular relates to a connection structure of an assembled pressure member and a construction method thereof. Background Art

[0002] Compression components are widely used in bridge engineering, such as arch ribs, piers and compression columns of arch bridges. The high compressive strength of UHPC can reduce the weight of compression components and make the compressive structure more widely applicable. For example, using box-shaped UHPC compression components as arch ribs can reduce the weight of arch bridge structures, increase the span capacity, and make the realization of long-span arch bridges possible; applying box-shaped UHPC compression components to compression columns can reduce their wall thickness and make the structure lighter.

[0003] Compared with fully cast-in-place compression components, prefabricated assembled compression components have the advantages of convenient construction, shortened construction period, guaranteed component quality, and protection of the on-site environment. Therefore, assembled box-shaped UHPC compression components have broad application prospects. However, assembled structures are prone to the following problems: the connection nodes are weaker than the prefabricated segments, and the overall structure is first damaged at the connection nodes, affecting the quality of the assembled structure; the integrity of the assembled structure is not strong, and the seismic performance is weak, so the assembled structure is difficult to be widely used in high-seismic fortification areas. Therefore, the development of efficient and safe connection structures between assembled box-shaped UHPC compression components is an urgent problem to be solved. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies and defects mentioned in the above background technology, and to provide a connection structure and construction method of assembled box-shaped UHPC compression components with simple structure, safety and reliability, high construction efficiency and low construction cost. In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0005] A connection structure for assembled box-shaped UHPC compression members, comprising a pair of adjacent box-shaped UHPC compression members and a pair of steel box beam joints arranged between the adjacent box-shaped UHPC compression members, wherein the pair of steel box beam joints are respectively connected to the pair of box-shaped UHPC compression members; one end of the steel box beam joint is pre-embedded and fitted in the inner cavity of the box-shaped UHPC compression member, and the other end extends to the outside of the box-shaped UHPC compression member to form an extended section, and the end of the extended section is provided with a connecting surface, and a plurality of through holes are opened on the connecting surface (the diameter d1 of the through holes and the connecting components is 10-50 mm); adjacent connecting surfaces are fitted, and the through holes on the adjacent connecting surfaces correspond to each other one by one, and the adjacent connecting surfaces are connected by connecting components arranged in the through holes.

[0006] In the connection structure for assembled box-shaped UHPC compression members, preferably, the length of the extension section is 0.1-1m, the connection surface is perpendicular to the extension section, and the outer edge of the connection surface does not exceed the outer surface of the extension section. The length and arrangement of the extension section are conducive to improving the structural stability of the connection node, and a sufficient length of the UHPC cast-in-place section is reserved, so that the cast-in-place UHPC section and the longitudinal steel bars extending from the two adjacent prefabricated box-shaped UHPC compression members are effectively anchored, ensuring the mechanical properties of the connection node for temporary connection and subsequent use.

[0007] In the above-mentioned connection structure for assembled box-shaped UHPC compression members, preferably, the inner cavity of the steel box girder joint is provided with a plurality of trapezoidal steel stiffening ribs, one end of the trapezoidal steel stiffening ribs is arranged against the connection surface; through holes are provided between adjacent trapezoidal steel stiffening ribs on the same side of the steel box girder joint, and the number of trapezoidal steel stiffening ribs on the same side of the steel box girder joint is not less than 3, the number of through holes on the same side is not less than 2, and the number of through holes on the chamfer is not less than 1. In the present invention, arranging trapezoidal steel stiffening ribs around the inner cavity of the steel box girder joint can effectively improve the stiffness and compression performance of the steel box girder joint, prevent local buckling of the steel box girder joint under pressure after connection, and ensure the stability and safety of the connection. The above-mentioned preferred number of trapezoidal steel stiffening ribs can ensure the stiffness and stability of the steel box girder joint, and the preferred number of through holes can ensure the reliability and safety of the connection of the box-shaped UHPC compression member.

[0008] In the above-mentioned connection structure for assembled box-shaped UHPC compression members, preferably, the height a7 of the trapezoidal steel stiffening rib is 0.2-1m, the long bottom side length b6 is 0.05-0.4m, the short bottom side length b7 is 0.02-0.2m, and the thickness b8 is 0.01-0.08m; the distance w1 between adjacent trapezoidal steel stiffening ribs located on the same side of the steel box beam joint is 0.1-0.8m; the long bottom side of the trapezoidal steel stiffening rib is against the connection surface.

[0009] In the above-mentioned connection structure for assembled box-shaped UHPC compression members, preferably, the ends of the four sides of the box-shaped UHPC compression member are protruding outward and are provided with a plurality of evenly distributed wedge-shaped key teeth, the outer convex side length a3 of the wedge-shaped key teeth is 0.2-0.6m, the inner concave side length a4 is 0.1-0.4m, the key tooth thickness b3 is 0.03-0.1m, the key tooth width h3 is 0.1-1m, and the distance e1 between the wedge-shaped key teeth and the edge of the box-shaped UHPC compression member is 0.2-1m. The number of wedge-shaped key teeth on each of the above-mentioned sides is not less than 2. In the present invention, the provision of wedge-shaped key teeth can improve the integrity of the UHPC compression segment cast on site and the box-shaped UHPC compression member prefabricated in the factory, and realize common force. In the present invention, the total length of the above-mentioned wedge-shaped key teeth must be less than the side length of the box-shaped UHPC compression member. In the present invention, other similar size restrictions also meet the above situation.

[0010] In the above connection structure for assembled box-shaped UHPC compression components, preferably, the inner cavity cross-section of the box-shaped UHPC compression component is a square with chamfers, the side lengths a1 and a2 of the box-shaped UHPC compression component are 1.0-8m, the wall thicknesses b1 and b2 are 0.1-1m, and the chamfer dimensions h1 and h2 are 0.1-1m. The preferred box-shaped UHPC compression component of the present invention saves materials, has a light weight, and can well meet the needs of the construction stage and the use stage.

[0011] In the connection structure for assembled box-shaped UHPC compression members, preferably, the steel box beam joint is a hollow structure, and the cross-sectional shape of the steel box beam joint is a square with chamfers, the side lengths a5 and a6 of the steel box beam joint are 0.6-7.6m, the length w3 is 0.4-4m, the steel plate thicknesses b4 and b9 are 10-80mm, the chamfer dimensions h4 and h5 are 0.1-0.5m, and the width b5 of the connection surface is 0.06-0.5m. If the chamfer dimensions of the steel box beam joint are appropriate, trapezoidal steel stiffening ribs are provided at the chamfers, and the distance w2 between them is 0.1-0.5m; if the chamfer dimensions of the steel box beam joint are too small, trapezoidal steel stiffening ribs are not provided at the chamfers.

[0012] In the present invention, the shape of the steel box girder joint is consistent with the shape of the box-shaped UHPC compression member and the size fits. When prefabricated in the factory, UHPC is directly cast on the outer surface of the steel box girder joint, which is convenient for construction and can ensure the connection performance between the box-shaped UHPC compression member and the steel box girder joint. In addition, the chamfer design is also convenient for on-site casting of UHPC. In the present invention, the steel box girder joint extends out of the surface of the prefabricated box-shaped UHPC compression member. After the box-shaped UHPC compression member is connected with connecting bolts, the extended part of the steel box girder joint can serve as the inner mold of the cast-in-place UHPC segment, which is conducive to casting. It can always participate in the force during the later use of the compression structure, improve the force performance at the connection node, and has better mechanical properties than dry joints. The outer edge of the connection surface of the steel box girder joint does not exceed the outer surface of the extended section. It is connected in the inner cavity with a connecting assembly, which can make the outer part of the steel box girder joint smooth and ensure that the cast-in-place UHPC segment is densely cast. In the later use process, the engineering personnel can enter the interior of the compression member to complete the inspection and replacement of the connection components to ensure the reliability of the connection structure. In addition, in the present invention, the shape of the steel box girder joint needs to be consistent with the shape of the box-shaped UHPC compression member, ensuring that the inner cavity size of the steel box girder joint is close to the inner cavity size and shape of the box-shaped UHPC compression member, ensuring the continuity of the overall structure, improving the mechanical properties of the connection structure, and improving the integrity and seismic performance of the connection structure.

[0013] In the above connection structure for assembled box-shaped UHPC compression members, preferably, the outer surface of the steel box girder joint is provided with a plurality of evenly distributed studs, the end of the box-shaped UHPC compression member is provided with a plurality of longitudinal bars extending outward, and the corresponding longitudinal bars between adjacent box-shaped UHPC compression members are staggered and arranged closely. The nominal diameter range of the above studs is 10-25mm, and the design value range of the length after welding is 40-300mm. The above preferred stud diameter and post-weld length enable the studs cast in the UHPC to provide strong shear resistance and pull-out resistance, which is a necessary guarantee for the good connection between the steel box girder joint and the box-shaped UHPC compression member.

[0014] The number of transverse rows of studs arranged on each straight-side outer surface of the above-mentioned steel box girder joint is equal to or more than 3 rows, the number of longitudinal rows of studs extending out of the prefabricated box-shaped UHPC compression member is equal to or more than 1 row, and the number of longitudinal rows of studs embedded in the box-shaped UHPC compression member is equal to or more than 2 rows. The number of transverse rows of studs arranged on each chamfered outer surface of the steel box girder joint is equal to or more than 1 row, the number of longitudinal rows of studs extending out of the prefabricated box-shaped UHPC compression member is equal to or more than 1 row, and the number of longitudinal rows of studs embedded in the box-shaped UHPC compression member is equal to or more than 2 rows. The stud spacing e2 in the transverse direction of the extended section is 100-500mm, and the stud spacing e4 in the longitudinal direction of the prefabricated section is 90-400mm. The distance e3 between the studs and the connection surface at the cast-in-place location is 40-200mm. In the present invention, the preferred number and arrangement of studs are conducive to uniformly and effectively transmitting various effects on the steel box girder joint to the box-shaped UHPC compression member, which can prevent the steel box girder connection head from rotating in various directions relative to the box-shaped UHPC compression member, thereby ensuring the connection performance between the sections of the box-shaped UHPC compression member.

[0015] The diameter of the above-mentioned longitudinal reinforcement is 12-28mm, and the diameter of the stirrup is 10-20mm. The longitudinal reinforcement spacing is 0.1-0.4m, and the stirrup spacing is 0.1-0.5m. The length of the longitudinal reinforcement extending out of the box-shaped UHPC compression member is 0.1-1m, and the length of the longitudinal reinforcement extending at the wedge-shaped key tooth is reduced by one key tooth thickness b3. After the box-shaped UHPC compression member is temporarily connected, equal to or more than 2 stirrups are tied to the longitudinal steel bars of the extended section. In the present invention, longitudinal reinforcement and stirrups are arranged inside the box-shaped UHPC compression member in the area near the steel box girder joint, which can effectively improve the force-bearing performance of the box-shaped UHPC compression member and prevent it from cracking at the connection with the steel box girder joint. After the longitudinal steel bars are extended and the stirrups are tied in the extended section and the UHPC is cast in situ, the staggered and adjacent longitudinal steel bars corresponding to the two adjacent prefabricated box-type UHPC compression members can be equivalent to a full-length steel bar under the effective anchoring action of UHPC, which can greatly improve the compression and tensile properties of the extended section. In addition, the connection structure between the segments of the box-type UHPC compression member will not be destroyed by tension in some accidental and unexpected situations (such as earthquakes), thereby improving the safety of the connection of the compression segment.

[0016] In the above connection structure for assembled box-shaped UHPC compression members, preferably, a UHPC casting layer is provided on the outer surface of a pair of steel box beam joints between adjacent box-shaped UHPC compression members, and the UHPC casting layer is flush with the outer surface of the box-shaped UHPC compression member.

[0017] As a general technical concept, the present invention also provides a construction method for a connection structure of assembled box-shaped UHPC compression members, comprising the following steps:

[0018] S1: Prefabricate box-shaped UHPC compression components in the factory, and embed steel box beam joints while prefabricating the box-shaped UHPC compression components so that the box-shaped UHPC compression components and the steel box beam joints form a whole;

[0019] S2: Fix a box-shaped UHPC compression member, then hoist the adjacent box-shaped UHPC compression member into place, so that the connection surfaces of the steel box beam joints on the two adjacent box-shaped UHPC compression members fit together and the through holes are aligned, and a connection assembly (operated in the internal abdominal cavity) is used to fix and connect the two adjacent connection surfaces through the through holes to complete the temporary connection;

[0020] S3: The longitudinal reinforcement between two adjacent box-shaped UHPC compression members is tied with stirrups, and an external formwork is set at the joints of adjacent steel box girders. A circular hole with a diameter of 0.1-0.5m is opened on the external formwork to facilitate the pouring of UHPC; UHPC is poured and cured, and the external formwork is removed after curing to complete the fixed connection between adjacent box-shaped UHPC compression members.

[0021] In the above construction method, when using multiple connection structures to construct an integral assembled box-shaped UHPC compression member, S2 can be repeated to complete the temporary connection of multiple box-shaped UHPC compression members before S3 is performed; S2-S3 can also be repeated to complete the fixed connection of multiple box-shaped UHPC compression members.

[0022] In the present invention, the steel box beam joint and the connecting bolts are both steel components, the wedge-shaped key teeth and the box-shaped UHPC compression component unit are both UHPC material components, and the bending tensile strength of the UHPC material is above 20MPa, and the compressive strength is above 100MPa (such as the preferred reactive powder concrete (RPC)). The use of steel box beam joints can ensure processing accuracy, facilitate connection, and the steel has high compressive strength, which can meet the requirements of compressive performance during the construction stage.

[0023] In the present invention, the wedge-shaped key teeth on the four sides of the end face of the box-shaped UHPC compression member are prefabricated and cast together with the box-shaped UHPC compression member in the factory. The steel box girder joint is prefabricated and fitted inside the box-shaped UHPC compression member, and is connected by bolts on the outer surface of the steel box girder joint to achieve common force. In the present invention, the connection assembly connects the two prefabricated segments together, which is convenient for supporting the outsourcing mold and casting UHPC at the joint during the construction stage, and can also improve the force performance at the connection node of the box-shaped UHPC compression member during the use stage.

[0024] In the present invention, after the adjacent box-shaped UHPC compression members are temporarily connected by connecting bolts, the formwork is outsourced and UHPC is poured from the circular hole, and then cured, so that the connection nodes are not weakened, but are stronger than the prefabricated sections, thereby ensuring the connection performance of the adjacent box-shaped UHPC compression member units.

[0025] The present invention adopts a form of cast-in-place UHPC after temporary connection between adjacent box-shaped UHPC compression component units using high-strength connection components, and limits the above-mentioned UHPC materials, box-shaped UHPC compression component units, steel box girder joint dimensions, etc., which makes the box-shaped UHPC compression component units of the present invention improve the construction convenience and feasibility while ensuring the connection performance of the segments.

[0026] Compared with the prior art, the advantages of the present invention are:

[0027] 1. The present invention uses a connection assembly to temporarily connect adjacent box-shaped UHPC compression members, and then casts UHPC for connection. No on-site welding is required, and the performance requirements at the connection nodes can be guaranteed. This avoids the problem of welding work in difficult welding environments (such as high-altitude welding) and the difficulty in ensuring welding quality. It also avoids the static performance and fatigue performance problems of the connection nodes caused by welding quality problems, and ensures the connection quality of the box-shaped UHPC compression members.

[0028] 2. After the connecting assembly is used to connect adjacent box-shaped UHPC compression member segments, the UHPC is cast on site and maintained, thereby ensuring the integrity of the structure. The UHPC cast-in-place segment and the steel box girder joint are subjected to stress together during use, thereby improving the mechanical properties and seismic resistance of the connection node, preventing damage caused by tension or other effects on the connection node in accidental and unexpected situations (such as earthquakes), thereby ensuring the reliability of the connection unit of the box-shaped UHPC compression member.

[0029] 3. The box-shaped UHPC compression member used in the present invention has a simple structure, high factory prefabrication, and has good stress-bearing performance by using steel box beam joints. During construction, multiple sections of box-shaped UHPC compression members can be temporarily connected first, with the steel box beam joints bearing the stress, and then the UHPC segments can be cast together, which greatly reduces the time for casting UHPC, effectively increases construction efficiency, and reduces construction costs.

[0030] 4. The box-shaped UHPC compression member connection structure adopted by the present invention is connected from the inside of the box-shaped member using a connection assembly during the construction phase. During the use phase, engineering personnel can enter the interior of the compression member to complete the inspection and replacement of the connection assembly to ensure the reliability of the connection structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 It is a schematic diagram of the structure after the box-shaped UHPC compression member is connected to the steel box girder joint in an embodiment of the present invention.

[0033] Figure 2 It is a schematic structural diagram of a steel box girder joint in an embodiment of the present invention.

[0034] Figure 3 Schematic diagram of the structure of the connection structure of the box-shaped UHPC compression member in an embodiment of the present invention.

[0035] Figure 4 for Figure 3 Top view of the .

[0036] Figure 5 It is a schematic diagram of the structure after the outer formwork is provided for the connection structure of the box-shaped UHPC compression member in an embodiment of the present invention.

[0037] Figure 6 4 is a cross-sectional view of a box-shaped UHPC compression member in an embodiment of the present invention.

[0038] Figure 7 1 is a top view of a box-shaped UHPC compression member in an embodiment of the present invention.

[0039] Figure 8 It is a front view of a box-shaped UHPC compression member in an embodiment of the present invention.

[0040] Fig. 9 It is a cross-sectional view of a steel box girder joint in an embodiment of the present invention.

[0041] Fig.10 It is a side view (dimension structure schematic diagram) of the steel box girder joint in an embodiment of the present invention.

[0042] Fig.11 Schematic diagram of the structure of the trapezoidal steel stiffening rib in an embodiment of the present invention.

[0043] Fig.12 It is a front view of the steel box girder joint in an embodiment of the present invention.

[0044] Fig.13 It is a side view of the steel box girder joint in an embodiment of the present invention.

[0045] Fig.14 It is a structural schematic diagram of the connection structure of the box-shaped UHPC compression member provided with the UHPC casting layer in an embodiment of the present invention.

[0046] Legend:

[0047] 1. Box-shaped UHPC compression member; 2. Steel box girder joint; 21. Extension section; 22. Connection surface; 23. Through hole; 3. Trapezoidal steel stiffening rib; 4. Wedge-shaped key teeth; 5. Studs; 6. Longitudinal reinforcement; 7. External formwork; 8. UHPC casting layer; 9. Connection components. DETAILED DESCRIPTION

[0048] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with the accompanying drawings and preferred embodiments of the present invention, but the protection scope of the present invention is not limited to the following specific embodiments.

[0049] Unless otherwise defined, all the professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0050] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0051] Embodiment 1:

[0052] like Figure 1-Figure 5 As shown, the connection structure for assembled box-shaped UHPC compression members of this embodiment includes a pair of adjacent box-shaped UHPC compression members 1 and a pair of steel box beam joints 2 arranged between the adjacent box-shaped UHPC compression members 1, and the pair of steel box beam joints 2 are respectively connected to the pair of box-shaped UHPC compression members 1; one end of the steel box beam joint 2 is pre-buried and fitted in the inner cavity of the box-shaped UHPC compression member 1, and the other end extends to the outside of the box-shaped UHPC compression member 1 to form an extension section 21, and the end of the extension section 21 is provided with a connection surface 22, and a plurality of through holes 23 are opened on the connection surface 22; adjacent connection surfaces 22 are fitted, and the through holes 23 on the adjacent connection surfaces 22 correspond to each other, and the adjacent connection surfaces 22 are connected by a connection assembly 9 arranged in the through holes 23. In this embodiment, the above-mentioned connection assembly 9 adopts a high-strength bolt.

[0053] In this embodiment, the box-shaped UHPC compression member is an arch rib for an extra-large span steel-UHPC composite truss arch bridge. The arch rib is a thin member, and the bending tensile strength of the UHPC material is above 20 MPa and the compressive strength is above 100 MPa.

[0054] In this embodiment, the length of the extended section 21 is 0.18 m, the connecting surface 22 is perpendicular to the extended section 21 , and the outer edge of the connecting surface 22 does not exceed the outer surface of the extended section 21 .

[0055] In this embodiment, the inner cavity of the steel box girder joint 2 is provided with a plurality of trapezoidal steel stiffening ribs 3, one end of the trapezoidal steel stiffening rib 3 is abutted against the connecting surface 22; a through hole 23 is provided between adjacent trapezoidal steel stiffening ribs 3 located on the same side of the steel box girder joint 2, and the number of the trapezoidal steel stiffening ribs 3 located on the same side of the steel box girder joint 2 is 6, the number of the through holes is 5, one through hole is provided on each chamfer, and the diameter d1 of the through hole is 0.03m.

[0056] like Fig.11 As shown, in this embodiment, the height a7 of the trapezoidal steel stiffening rib 3 is 0.48m, the long bottom side length b6 is 0.1m, the short bottom side length b7 is 0.05m, and the thickness b8 is 0.02m; the distance w1 between adjacent trapezoidal steel stiffening ribs 3 located on the same side of the steel box girder joint 2 is 0.21m, and the distance w2 between the trapezoidal steel stiffening ribs 3 at the chamfer is 0.16m; the long bottom side of the trapezoidal steel stiffening rib 3 is against the connecting surface 22.

[0057] like Figure 7 , 8 As shown, in this embodiment, the ends of the four sides of the box-shaped UHPC compression member 1 protrude outward and are evenly provided with a plurality of wedge-shaped key teeth 4, the outer convex side length a3 of the wedge-shaped key teeth 4 is 0.3m, the inner concave side length a4 is 0.24m, the key tooth thickness b3 is 0.05m, the key tooth width h3 is 0.2m, the distance e1 between the wedge-shaped key teeth 4 and the edge of the box-shaped UHPC compression member 1 is 0.4m, and 3 wedge-shaped key teeth 4 are arranged on each side.

[0058] like Figure 6 As shown, in this embodiment, the inner cavity cross-section of the box-shaped UHPC compression component 1 is a square with chamfers, the side lengths a1 and a2 of the box-shaped UHPC compression component 1 are 2 m, the wall thicknesses b1 and b2 are 0.2 m, and the chamfer dimensions h1 and h2 are 0.2 m.

[0059] like Fig. 9 , 10 As shown, in this embodiment, the steel box girder joint 2 is a hollow structure, and the cross-sectional shape of the steel box girder joint 2 is a square with chamfers, the side lengths a5 and a6 of the steel box girder joint 2 are 1.2 m, the length w3 is 0.78 m, the steel plate thicknesses b4 and b9 are 20 mm, the chamfer dimensions h4 and h5 are 0.2 m, and the width b5 of the connection surface is 0.12 m.

[0060] like Fig.12 , 13As shown, in this embodiment, the outer surface of the steel box girder joint 2 is provided with a plurality of evenly distributed studs 5, and the end of the box-shaped UHPC compression member 1 is provided with a plurality of longitudinal bars 6 extending outward, and the corresponding longitudinal bars 6 between adjacent box-shaped UHPC compression members 1 are arranged in a staggered and close manner. The nominal diameter of the stud 5 is 19 mm, and the design value of the length after welding is 120 mm. Six rows of studs 5 are arranged transversely on the outer surface of each straight edge of the steel box girder joint 2, one row of studs 5 is arranged longitudinally on the part extending out of the box-shaped UHPC compression member 1, and four rows of studs 5 are arranged longitudinally in the box-shaped UHPC compression member 1. One row of studs 5 is arranged transversely on each chamfered outer surface of the steel box girder joint 2, one row of studs 5 is arranged longitudinally on the part extending out of the box-shaped UHPC compression member 1, and four rows of studs 5 are arranged longitudinally in the box-shaped UHPC compression member 1. The spacing e2 of the studs 5 in the transverse direction of the extended section 21 is 0.2m, the spacing e4 of the studs 5 in the longitudinal direction is 0.12m, and the distance e3 between the studs 5 and the connection surface 22 at the extended section 21 is 80mm. The diameter of the longitudinal reinforcement 6 is 20mm, the spacing of the longitudinal reinforcement 6 is 230mm, the diameter of the stirrups is 12mm, the spacing of the stirrups is 150mm, and two stirrups are tied to the longitudinal reinforcement 6.

[0061] like Fig.14 As shown, in this embodiment, a UHPC casting layer 8 is provided on the outer surface of a pair of steel box beam joints 2 between adjacent box-shaped UHPC compression members 1 , and the UHPC casting layer 8 is flush with the outer surface of the box-shaped UHPC compression member 1 .

[0062] This embodiment also provides a construction method for the connection structure of assembled box-shaped UHPC compression components, comprising the following steps:

[0063] S1: Prefabricate a plurality of box-shaped UHPC compression members 1 in a factory, and embed the steel box beam joint 2 while prefabricating the box-shaped UHPC compression members 1 so that the box-shaped UHPC compression members 1 and the steel box beam joint 2 form a whole;

[0064] S2: First, fix a box-shaped UHPC compression member 1, then hoist the adjacent box-shaped UHPC compression member 1 into place, so that the connection surfaces 22 of the steel box beam joints 2 on the two adjacent box-shaped UHPC compression members 1 fit together, and the through holes 23 are aligned, and use a connection assembly 9 to fix and connect the two adjacent connection surfaces 22 through the through holes 23 to complete the temporary connection;

[0065] S3: The longitudinal reinforcement 6 between two adjacent box-shaped UHPC compression members 1 is tied with stirrups, and an outer formwork 7 is supported at the adjacent steel box beam joints 2. A circular hole with a diameter of 360 mm is opened in the outer formwork 7 to facilitate the pouring of UHPC. The UHPC is poured and cured. After the curing, the outer formwork 7 is removed, and the fixed connection between the adjacent box-shaped UHPC compression members 1 is completed.

[0066] Embodiment 2:

[0067] like Figure 1-Figure 5 As shown, the connection structure for assembled box-shaped UHPC compression members of this embodiment includes a pair of adjacent box-shaped UHPC compression members 1 and a pair of steel box beam joints 2 arranged between the adjacent box-shaped UHPC compression members 1, and the pair of steel box beam joints 2 are respectively connected to the pair of box-shaped UHPC compression members 1; one end of the steel box beam joint 2 is pre-buried and fitted in the inner cavity of the box-shaped UHPC compression member 1, and the other end extends to the outside of the box-shaped UHPC compression member 1 to form an extension section 21, and the end of the extension section 21 is provided with a connection surface 22, and a plurality of through holes 23 are opened on the connection surface 22; adjacent connection surfaces 22 are fitted, and the through holes 23 on the adjacent connection surfaces 22 correspond to each other, and the adjacent connection surfaces 22 are connected by a connection assembly 9 arranged in the through holes 23. In this embodiment, the above-mentioned connection assembly 9 adopts a high-strength bolt.

[0068] In this embodiment, the box-shaped UHPC compression member is a compression column, the compression column is a thin member, and the bending tensile strength of the UHPC material is above 20 MPa and the compressive strength is above 100 MPa.

[0069] In this embodiment, the length of the extended section 21 is 0.1 m, the connecting surface 22 is perpendicular to the extended section 21 , and the outer edge of the connecting surface 22 does not exceed the outer surface of the extended section 21 .

[0070] In this embodiment, the inner cavity of the steel box girder joint 2 is provided with a plurality of trapezoidal steel stiffening ribs 3, one end of the trapezoidal steel stiffening rib 3 is abutted against the connecting surface 22; a through hole 23 is provided between adjacent trapezoidal steel stiffening ribs 3 located on the same side of the steel box girder joint 2, and the number of the trapezoidal steel stiffening ribs 3 located on the same side of the steel box girder joint 2 is 5, the number of the through holes is 4, one through hole is provided on each chamfer, and the diameter d1 of the through hole is 0.024m.

[0071] In this embodiment, the height a7 of the trapezoidal steel stiffening rib 3 is 0.36m, the long bottom side length b6 is 0.1m, the short bottom side length b7 is 0.04m, and the thickness b8 is 0.015m; the distance w1 between adjacent trapezoidal steel stiffening ribs 3 located on the same side of the steel box girder joint 2 is 0.192m, and no trapezoidal steel stiffening rib 3 is arranged at the chamfer; the long bottom side of the trapezoidal steel stiffening rib 3 is abutted against the connecting surface 22.

[0072] In this embodiment, the ends of the four sides of the box-shaped UHPC compression member 1 protrude outward and are evenly provided with a plurality of wedge-shaped key teeth 4, the outer convex side length a3 of the wedge-shaped key teeth 4 is 0.23m, the inner concave side length a4 is 0.18m, the key tooth thickness b3 is 0.04m, the key tooth width h3 is 0.15m, the distance e1 between the wedge-shaped key teeth 4 and the edge of the box-shaped UHPC compression member 1 is 0.3m, and three wedge-shaped key teeth 4 are arranged on each side.

[0073] In this embodiment, the inner cross-section of the box-shaped UHPC compression component 1 is a square with chamfers, the side lengths a1 and a2 of the box-shaped UHPC compression component 1 are 1.5 m, the wall thicknesses b1 and b2 are 0.15 m, and the chamfer dimensions h1 and h2 are 0.15 m.

[0074] In this embodiment, the steel box girder joint 2 is a hollow structure, and the cross-sectional shape of the steel box girder joint 2 is a square with chamfers. The side lengths a5 and a6 of the steel box girder joint 2 are 0.9 m, the length w3 is 0.6 m, the steel plate thicknesses b4 and b9 are 15 mm, the chamfer dimensions h4 and h5 are 0.15 m, and the width b5 of the connecting surface is 0.115 m.

[0075] In this embodiment, the outer surface of the steel box girder joint 2 is provided with a plurality of evenly distributed studs 5, and the end of the box-shaped UHPC compression member 1 is provided with a plurality of longitudinal bars 6 extending outward, and the corresponding longitudinal bars 6 between adjacent box-shaped UHPC compression members 1 are arranged in a staggered and close manner. The nominal diameter of the stud 5 is 13 mm, and the design value of the length after welding is 90 mm. Five rows of studs 5 are arranged transversely on the outer surface of each straight edge of the steel box girder joint 2, one row of studs 5 is arranged longitudinally on the part extending out of the box-shaped UHPC compression member 1, and four rows of studs 5 are arranged longitudinally in the box-shaped UHPC compression member 1. One row of studs 5 is arranged transversely on each chamfered outer surface of the steel box girder joint 2, one row of studs 5 is arranged longitudinally on the part extending out of the box-shaped UHPC compression member 1, and four rows of studs 5 are arranged longitudinally in the box-shaped UHPC compression member 1. The spacing e2 of the studs 5 in the transverse direction of the extended section 21 is 0.18m, the spacing e4 of the studs 5 in the longitudinal direction is 0.11m, and the distance e3 between the studs 5 and the connection surface 22 at the extended section 21 is 60mm. The diameter of the longitudinal reinforcement 6 is 18mm, the spacing of the longitudinal reinforcement 6 is 200mm, the diameter of the stirrups is 10mm, the spacing of the stirrups is 120mm, and two stirrups are tied to the longitudinal reinforcement 6.

[0076] like Fig.14 As shown, in this embodiment, a UHPC casting layer 8 is provided on the outer surface of a pair of steel box beam joints 2 between adjacent box-shaped UHPC compression members 1 , and the UHPC casting layer 8 is flush with the outer surface of the box-shaped UHPC compression member 1 .

[0077] The preparation method of this embodiment is similar to that of embodiment 1, and the specific process is referred to embodiment 1.

Claims

1. A connection structure for assembled box-shaped UHPC compression components, characterized in that: The invention comprises a pair of adjacently arranged box-shaped UHPC compression members (1) and a pair of steel box beam joints (2) arranged between the adjacent box-shaped UHPC compression members (1), wherein the pair of steel box beam joints (2) are respectively connected to the pair of box-shaped UHPC compression members (1); one end of the steel box beam joint (2) is pre-buried and fitted in the inner cavity of the box-shaped UHPC compression member (1), and the other end extends to the outside of the box-shaped UHPC compression member (1) to form an extended section (21); a connecting surface (22) is provided at the end of the extended section (21), and a plurality of through holes (23) are provided on the connecting surface (22); adjacent connecting surfaces (22) are fitted, and the through holes (23) on adjacent connecting surfaces (22) correspond to each other one by one, and adjacent connecting surfaces (22) are connected via a connecting assembly (9) provided in the through holes (23); The length of the extended section (21) is 0.1-1 m, the connecting surface (22) is perpendicular to the extended section (21), and the outer edge of the connecting surface (22) does not exceed the outer surface of the extended section (21).

2. The connection structure for assembled box-shaped UHPC compression components according to claim 1, characterized in that: The inner cavity of the steel box girder joint (2) is provided with a plurality of trapezoidal steel stiffening ribs (3), one end of each of the trapezoidal steel stiffening ribs (3) being disposed against the connection surface (22); through holes (23) are provided between adjacent trapezoidal steel stiffening ribs (3) located on the same side of the steel box girder joint (2), and the number of the trapezoidal steel stiffening ribs (3) located on the same side of the steel box girder joint (2) is not less than 3.

3. The connection structure for assembling box-shaped UHPC compression components according to claim 2, characterized in that: The height a7 of the trapezoidal steel stiffening rib (3) is 0.2-1m, the long bottom side length b6 is 0.05-0.4m, the short bottom side length b7 is 0.02-0.2m, and the thickness b8 is 0.01-0.08m; the distance w1 between adjacent trapezoidal steel stiffening ribs (3) located on the same side of the steel box girder joint (2) is 0.1-0.8m; and the long bottom side of the trapezoidal steel stiffening rib (3) is abutted against the connection surface (22).

4. The connection structure for assembling box-shaped UHPC compression components according to claim 1, characterized in that: The ends of the four sides of the box-shaped UHPC compression component (1) are protruding outwards and are provided with a plurality of evenly distributed wedge-shaped key teeth (4); the outer convex side length a3 of the wedge-shaped key teeth (4) is 0.2-0.6 m, the inner concave side length a4 is 0.1-0.4 m, the key tooth thickness b3 is 0.03-0.1 m, the key tooth width h3 is 0.1-1 m, and the distance e1 between the wedge-shaped key teeth (4) and the edge of the box-shaped UHPC compression component (1) is 0.2-1 m.

5. The connection structure for assembled box-shaped UHPC compression components according to any one of claims 1 to 4, characterized in that: The inner cavity cross-section of the box-shaped UHPC pressure-bearing component (1) is a square with chamfers, the side lengths a1 and a2 of the box-shaped UHPC pressure-bearing component (1) are 1.0-8 m, the wall thicknesses b1 and b2 are 0.1-1 m, and the chamfer dimensions h1 and h2 are 0.1-1 m.

6. The connection structure for assembled box-shaped UHPC compression members according to any one of claims 1 to 4, characterized in that: The steel box girder joint (2) is a hollow structure, and the cross-sectional shape of the steel box girder joint (2) is a square with chamfers, the side lengths a5 and a6 of the steel box girder joint (2) are 0.6-7.6 m, the length w3 is 0.4-4 m, the steel plate thicknesses b4 and b9 are 10-80 mm, the chamfer dimensions h4 and h5 are 0.1-0.5 m, and the width b5 of the connection surface is 0.06-0.5 m.

7. The connection structure for assembled box-shaped UHPC compression members according to any one of claims 1 to 4, characterized in that: The outer surface of the steel box girder joint (2) is provided with a plurality of evenly distributed studs (5), the end of the box-shaped UHPC compression member (1) is provided with a plurality of longitudinal bars (6) extending outward, and the corresponding longitudinal bars (6) between adjacent box-shaped UHPC compression members (1) are staggered and closely arranged.

8. The connection structure for assembled box-shaped UHPC compression components according to any one of claims 1 to 4, characterized in that: A UHPC casting layer (8) is provided on the outer surfaces of a pair of steel box beam joints (2) between adjacent box-shaped UHPC compression components (1), and the UHPC casting layer (8) is flush with the outer surface of the box-shaped UHPC compression component (1).

9. A construction method for a connection structure of assembled box-shaped UHPC compression members according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: prefabricating a box-shaped UHPC compression member (1) in a factory, and pre-embedding a steel box beam joint (2) while prefabricating the box-shaped UHPC compression member (1) so that the box-shaped UHPC compression member (1) and the steel box beam joint (2) form a whole; S2: Fixing a box-shaped UHPC compression member (1), and then hoisting an adjacent box-shaped UHPC compression member (1) into place, so that the connection surfaces (22) of the steel box beam joints (2) on the two adjacent box-shaped UHPC compression members (1) fit together and the through holes (23) are aligned, and using a connection assembly (9) to fix and connect the two adjacent connection surfaces (22) through the through holes (23), thereby completing the temporary connection; S3: The longitudinal reinforcement (6) between two adjacent box-shaped UHPC compression members (1) is tied with stirrups, an external formwork (7) is set at the adjacent steel box beam joints (2), UHPC is poured and cured, and the external formwork (7) is removed after curing, thereby completing the fixed connection between the adjacent box-shaped UHPC compression members (1).

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