Externally encased prefabricated UHPC slab arch bridge with concrete-filled steel tube stiff skeleton

Abstract

An externally encased prefabricated ultra-high-performance concrete (UHPC) slab arch bridge with a concrete-filled steel tube stiff skeleton is provided. The arch bridge includes a concrete-filled steel tube stiff skeleton arch rib segment, where the concrete-filled steel tube stiff skeleton arch rib segment is arranged at four corners inside a concrete-filled steel tube stiff skeleton externally encased prefabricated UHPC slab arch rib segment, and the concrete-filled steel tube stiff skeleton externally encased prefabricated UHPC slab arch rib segment includes two web structures, where the top and bottom of the two web structures are respectively connected to a roof structure and a floor structure through a cast-in-situ UHPC longitudinal joint and a cast-in-situ UHPC transverse joint. The stiff skeleton externally encased concrete is prefabricated into a UHPC slab and then transported to the site for assembly, the UHPC is used as externally encased concrete to reduce the self-weight of the structure.

Claims

1. An externally encased prefabricated ultra-high-performance concrete (UHPC) slab arch bridge with a concrete-filled steel tube stiff skeleton, comprising: a concrete-filled steel tube stiff skeleton arch rib segment, wherein the concrete-filled steel tube stiff skeleton arch rib segment is arranged at four corners inside a concrete-filled steel tube stiff skeleton externally encased prefabricated UHPC slab arch rib segment, and the concrete-filled steel tube stiff skeleton externally encased prefabricated UHPC slab arch rib segment comprises two web structures, wherein a top and a bottom of the two web structures are respectively connected to a roof structure and a floor structure through a cast-in-situ UHPC longitudinal joint and a cast-in-situ UHPC transverse joint; wherein the concrete-filled steel tube stiff skeleton arch rib segment comprises a hollow steel tube truss arch rib segment, core concrete is poured inside the hollow steel tube truss arch rib segment, and the hollow steel tube truss arch rib segment is fixedly connected to the cast-in-situ UHPC longitudinal joint through a plurality of headed studs; wherein each of the two web structures comprises a prefabricated UHPC web, and a prefabricated UHPC web steel mesh arranged uniformly and equidistantly is distributed on the prefabricated UHPC web; wherein the roof structure comprises a prefabricated UHPC roof, and a prefabricated UHPC roof steel mesh arranged uniformly and equidistantly is distributed on the prefabricated UHPC roof; and wherein the floor structure comprises a prefabricated UHPC floor, and a prefabricated UHPC floor steel mesh arranged uniformly and equidistantly is distributed on the prefabricated UHPC floor.

2. A construction method for the externally encased prefabricated UHPC slab arch bridge with the concrete-filled steel tube stiff skeleton according to claim 1, comprising: S1: prefabricating the prefabricated UHPC roof, the prefabricated UHPC floor and the prefabricated UHPC web in a concrete prefabrication factory, prefabricating the hollow steel tube truss arch rib segment in a steel structure prefabrication factory, and welding the plurality of headed studs in a welding factory; S2: erecting the concrete-filled steel tube stiff skeleton arch rib segment with headed studs at a construction site; S3: transporting the prefabricated UHPC roof, the prefabricated UHPC floor and the prefabricated UHPC web to the construction site for assembly, wherein the prefabricated UHPC roof, the prefabricated UHPC floor and the prefabricated UHPC web are connected into a whole by the plurality of headed studs and the cast-in-situ UHPC longitudinal joint; and S4: after completing the above steps, connecting an arch rib is longitudinally into a plurality of concrete-filled steel tube stiff skeleton externally encased prefabricated UHPC slab arch rib segments, and connecting the plurality of concrete-filled steel tube stiff skeleton externally encased prefabricated UHPC slab arch rib segments to form a concrete-filled steel tube stiff skeleton arch rib through the cast-in-situ UHPC transverse joint; wherein a steel bar in cast-in-situ UHPC longitudinal joint arranged uniformly and equidistantly is distributed on the cast-in-situ UHPC longitudinal joint.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram of a cross-sectional structure of an externally encased prefabricated UHPC slab arch bridge with a concrete-filled steel tube stiff skeleton.

(2) FIG. 2 is a schematic diagram of a concrete-filled steel tube stiff skeleton arch rib segment structure of an externally encased prefabricated UHPC slab arch bridge with a concrete-filled steel tube stiff skeleton.

(3) FIG. 3 is a schematic diagram of a facade structure of an externally encased prefabricated UHPC slab arch bridge with a concrete-filled steel tube stiff skeleton.

REFERENCE NUMERALS IN FIGURES

(4) 1a concrete-filled steel tube stiff skeleton arch rib segment; 2a prefabricated UHPC web; 3a cast-in-situ UHPC longitudinal joint; 4a prefabricated UHPC roof; 5a prefabricated UHPC floor; 6a prefabricated UHPC web steel mesh; 7a prefabricated UHPC floor steel mesh; 8a prefabricated UHPC roof steel mesh; 9a headed stud; 10a hollow steel tube truss arch rib segment; 11core concrete; 12a steel bar in cast-in-situ UHPC longitudinal joint; 13a cast-in-situ UHPC transverse joint; 14a concrete-filled steel tube stiff skeleton externally encased prefabricated UHPC slab arch rib segment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(5) The technical scheme of the present invention is further explained below by drawings and embodiments.

(6) Unless otherwise defined, the technical or scientific terms used in the present invention shall be those to which the present invention belongs. As used herein, the terms first, second, and the like do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Similar words such as comprise or include means that the elements or items preceding the word encompass the elements or items listed after the word and equivalents thereof, but do not exclude other elements or items. The terms connected or connection are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Up, down, left, right, etc. are only used to indicate a relative positional relationship, which may change accordingly when the absolute position of the object being described changes.

EMBODIMENT

(7) As shown in FIGS. 1-3, the present invention provides the externally encased prefabricated UHPC slab arch bridge with the concrete-filled steel tube stiff skeleton, including the concrete-filled steel tube stiff skeleton arch rib segment 1, wherein the concrete-filled steel tube stiff skeleton arch rib segment 1 is arranged at four corners inside the concrete-filled steel tube stiff skeleton externally encased prefabricated UHPC slab arch rib segment 14, and the concrete-filled steel tube stiff skeleton externally encased prefabricated UHPC slab arch rib segment 14 includes two web structures, wherein the top and bottom of the two web structures are respectively connected to the roof structure and the floor structure through the cast-in-situ UHPC longitudinal joint 3 and the cast-in-situ UHPC transverse joint 13.

(8) The concrete-filled steel tube stiff skeleton arch rib segment 1 includes the hollow steel tube truss arch rib segment 10, core concrete 11 is poured inside the hollow steel tube truss arch rib segment 10, and the hollow steel tube truss arch rib segment 10 is fixedly connected to the cast-in-situ UHPC longitudinal joint 3 through a plurality of headed studs 9.

(9) The web structure includes the prefabricated UHPC web 2, and the prefabricated UHPC web steel mesh 6 arranged uniformly and equidistantly is distributed on the prefabricated UHPC web 2.

(10) The roof structure includes the prefabricated UHPC roof 4, and the prefabricated UHPC roof steel mesh 8 arranged uniformly and equidistantly is distributed on the prefabricated UHPC roof 4.

(11) The floor structure includes the prefabricated UHPC floor 5, and the prefabricated UHPC floor steel mesh 7 arranged uniformly and equidistantly is distributed on the prefabricated UHPC floor 5.

(12) The steel bar in cast-in-situ UHPC longitudinal joint 12 arranged uniformly and equidistantly is distributed on the cast-in-situ UHPC longitudinal joint 3.

(13) The working principle is as follows: S1: the required prefabricated UHPC roof 4, prefabricated UHPC floor 5 and prefabricated UHPC web 2 are prefabricated in the concrete prefabrication factory, the hollow steel tube truss arch rib segment 10 is prefabricated in the steel structure prefabrication factory and the headed studs 9 required to connect the various components are welded in the factory. S2: the concrete-filled steel tube stiff skeleton arch rib segment 1 with headed studs 9 is erected at the construction site. S3: the prefabricated UHPC roof 4, prefabricated UHPC floor 5 and prefabricated UHPC web 2 are transported to the construction site for assembly, and the prefabricated UHPC roof 4, prefabricated UHPC floor 5 and prefabricated UHPC web 2 are connected into a whole by pre-welded headed studs 9 and cast-in-situ UHPC longitudinal joint 3. S4: after completing the above steps, the arch rib is longitudinally connected into a plurality of concrete-filled steel tube stiff skeleton externally encased prefabricated UHPC slab arch rib segments 14, and the plurality of concrete-filled steel tube stiff skeleton externally encased prefabricated UHPC slab arch rib segments 14 are connected to form the concrete-filled steel tube stiff skeleton arch rib through the cast-in-situ UHPC transverse joint 13.

(14) The welding work of headed stud 9 is completed in the prefabricated factory to avoid the risk of high-altitude welding at the construction site.

(15) The strength grade of the ordinary concrete filled in the hollow steel tube truss arch rib segment 10 and the prefabricated UHPC slab in factory is selected according to the actual engineering structure requirements.

(16) The segment length of prefabricated UHPC roof 4, prefabricated UHPC floor 5 and prefabricated UHPC web 2 can be determined according to the hoisting capacity of the construction site and in combination with the self-weight of the prefabricated UHPC slab.

(17) All the prefabricated UHPC roof steel mesh 8, prefabricated UHPC floor steel mesh 7 and prefabricated UHPC web steel mesh 6 of the prefabricated UHPC roof 4, prefabricated UHPC floor 5 and prefabricated UHPC web 2 are reserved for a certain length beyond the prefabricated slab, extended to the cast-in-situ UHPC longitudinal joint 3 and cast-in-situ UHPC transverse joint 13 to ensure its anchoring effect.

(18) The amount of steel fiber in the prefabricated UHPC roof 4, prefabricated UHPC floor 5 and prefabricated UHPC web 2 is selected appropriately according to different engineering requirements.

(19) The transverse steel bar of the prefabricated UHPC web 2, the prefabricated UHPC roof 4, and the prefabricated UHPC floor 5 of the same section should be arranged in a staggered manner to avoid clashes, similarly, the longitudinal steel bar of the adjacent concrete-filled steel tube stiff skeleton externally encased prefabricated UHPC slab arch rib segment 14 should also be arranged in a staggered manner to avoid clashes.

(20) Therefore, the present invention adopts the above-mentioned externally encased prefabricated UHPC slab arch bridge with the concrete-filled steel tube stiff skeleton, the externally encased concrete of the conventional concrete-filled steel tube stiff skeleton arch bridge is prefabricated into the UHPC slab, which can reduce the cast-in-situ concrete by more than 70% at the construction site, greatly reduce the construction of formwork and steel bars, and improve the construction efficiency at the site, meanwhile, prefabrication in the factory eliminates the shrinkage and creep of concrete caused by the age difference of concrete pouring successively, thus slowing down the micro-cracks of externally encased concrete caused by shrinkage and creep, additionally, it can avoid the waste of materials caused by the use of a large number of wood formwork in the cast-in-situ concrete. The conventional externally encased ordinary concrete is improved to externally encased UHPC, because the ultra-high mechanical properties of UHPC can reduce its release and reduce its self-weight compared with the conventional externally encased ordinary concrete under the condition of ensuring the same bearing capacity, so it has the potential to further improve the stiff skeleton arch bridge.

(21) Finally, it should be noted that the above examples are merely used for describing the technical solutions of the present invention, rather than limiting the same. Although the present invention has been described in detail with reference to the preferred examples, those of ordinary skill in the art should understand that the technical solutions of the present invention may still be modified or equivalently replaced. However, these modifications or substitutions should not make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.