Lightweight fabricated column-plate combined box-type high pier structure and construction process thereof

Abstract

The invention discloses a light-weight assembly type column and plate combined box type high pier structure and a construction technology thereof. The high pier structure comprises a cast-in-place bearing platform, a prefabricated pier body and a cast-in-place cover beam. The prefabricated pier body comprises a prefabricated slab and at least two prefabricated columns, the prefabricated slab is arranged between the two adjacent prefabricated columns, and the two sides of the prefabricated slab are connected with the two prefabricated columns respectively; the prefabricated plate is formed by splicing a plurality of plate sections; the prefabricated column comprises a pier top solid section, a standard section and a pier bottom solid section. The standard section is formed by splicing a plurality of column sections; the pier top solid section is connected with the cast-in-place bent cap, and the pier bottom solid section is connected with the cast-in-place bearing platform. The UHPC wet joints, the section steel-UHPC combined wet joints, the partially prestressed column segment joint technology and the multi-column segment continuous rapid construction technology are adopted, so that pier body light-weight assembly type construction is achieved, and the structure is simple in structure, convenient to construct, good in durability, good in economical efficiency, capable of saving energy, environmentally friendly and wide in application and popularization prospect.

Description

Technical Field

[0001] The present invention relates to the field of bridge engineering, and more specifically, to a lightweight assembled column-slab combined box-type high pier structure and a construction process thereof. Background Art

[0002] With the continuous development of my country's transportation infrastructure, higher and higher requirements have been put forward for bridge construction. Based on the national concept of safety, durability, energy conservation and environmental protection, the standardization, assembly and factory construction of bridge components have gradually become a consensus. Therefore, prefabrication and assembly technology that facilitates standardization, assembly and factory construction has developed rapidly and become the mainstream development direction of bridge construction.

[0003] At present, the prefabrication and assembly technology of bridge superstructures in my country has been developed to a relatively mature level, and the superstructures of small and medium-span bridges are basically constructed by assembly. For the substructure, the prefabrication and assembly technology is in the exploratory stage, and some urban bridges, cross-sea bridges, and highway bridges with conditions have gradually carried out the application and research of prefabrication and assembly pier technology.

[0004] However, in view of the current technology, prefabricated bridge piers are basically applied to shorter bridge piers and cannot be widely used in high piers. In addition, the cost of prefabricated bridge piers is generally higher than that of cast-in-place bridge piers. The current technical limitations are mainly: 1) The joint structure is complex or the construction is difficult, so the design generally tries to minimize the joints. The height of the prefabricated segments is generally large, and the weight of the prefabricated segments is large, which is not convenient for transportation and installation, especially for high-pier bridges in mountainous areas. 2) In order to ensure the reliable force of the pier body, most prefabricated bridge piers currently use dry joints or adhesive joints, and grouting sleeves to connect steel bars. This technology requires precise docking of the segments, and the matching prefabrication between the segments is required. It has high construction requirements, especially for high piers. It is difficult to control the verticality of the pier body. In addition, the large amount of grouting sleeves also increases the project cost; 3) In order to overcome the shortcomings of dry joints or adhesive joints, some prefabricated bridge piers use cast-in-place wet joint connection technology, which eliminates the need for steel bar connection and facilitates the adjustment of the verticality of the pier body. However, the steel bars in the wet joints are staggered, and the cast-in-place joint materials are used. The bonding of concrete or UHPC and steel bars realizes continuous stress on the pier body, and the stress performance of the joints is relatively poor. For high piers, the stress is large and the number of joints is large. The stress reliability of the pier body is reduced by using this joint technology. In addition, wet joints rely on bonding to transmit force, so the height of wet joints is generally large, and the material consumption is large, which increases the project cost. At the same time, since it is necessary to wait for the wet joints to reach the design strength before the next section can be constructed during the construction process, there are many joints for high piers and the construction period is very long; 4) Currently, prestressed technology is rarely used in prefabricated bridge piers. The main reason is that prestressed construction is relatively complicated, especially for the extension of multiple sections of prestressed steel bars, the construction process is more complicated and the construction period is longer. In addition, compared with reinforced concrete piers, prestressed concrete piers have reduced ductility and relatively poor seismic performance, which is particularly unfavorable for high piers.

[0005] Therefore, in view of the above situation, how to improve the structure and construction technology of bridge piers to enhance the construction convenience, stress resistance, durability and economy, so that the bridge piers can be more suitable for the assembly construction of high bridge piers, has become an important technical problem that needs to be urgently solved by technical personnel in this field. Summary of the invention

[0006] The present invention discloses a lightweight assembled column-slab combined box-type high pier structure, comprising a cast-in-place cap, a prefabricated pier body and a cast-in-place cap beam; the prefabricated pier body comprises a prefabricated plate and at least two prefabricated columns, the prefabricated plate is arranged between two adjacent prefabricated columns, and its two sides are respectively connected to the two prefabricated columns; the prefabricated plate is composed of a plurality of plate segments spliced ​​together; the prefabricated column comprises a pier top solid section, a standard section and a pier bottom solid section; the standard section is composed of a plurality of column sections spliced ​​together; the pier top solid section is connected to the cast-in-place cap beam, and the pier bottom solid section is connected to the cast-in-place cap.

[0007] Preferably, a plurality of prestressed steel bar embedded pipes are provided on the column segment, and the prestressed steel bar embedded pipes on two adjacent column segments are connected by a snap-on sleeve; prestressed coarse steel bars are provided in the prestressed steel bar embedded pipes, and two adjacent prestressed coarse steel bars are connected by a connector; and two adjacent column segments are connected by a UHPC wet joint.

[0008] Preferably, dry joints are used between two adjacent plate segments, and shear keys are arranged to engage with each other; the plate segment and the corresponding column segment are staggered; the plate segment and the corresponding column segment are connected through a steel-UHPC combined wet joint; the steel-UHPC combined wet joint includes embedded channel steel, embedded steel sleeve, connecting angle steel, connecting steel bars and cast-in-place UHPC; the embedded channel steel is arranged in the column segment, the embedded steel sleeve is arranged in the plate segment, the embedded channel steel and the embedded steel sleeve are connected through the connecting angle steel, the connecting steel bar includes column-side steel bars and plate-side steel bars, and the cast-in-place UHPC connects the column-side steel bars and the plate-side steel bars.

[0009] Preferably, the column segment is a box-shaped structure, and its cross-section is a hollow rectangular structure; the plate segment includes two mutually parallel transverse plates, and the ends of the two transverse plates are connected to one side surface of the column segment; the prestressed steel bar embedded pipe is distributed at intervals along the side wall of the column segment, and the interior of the column segment is provided with an inner reinforcement layer and an outer reinforcement layer; the inner reinforcement layer includes a plurality of inner longitudinal reinforcements and a plurality of inner stirrups, and the plurality of inner longitudinal reinforcements are distributed in a rectangular shape, and the surfaces of the inner stirrups are connected to the inner longitudinal reinforcements; the outer reinforcement layer includes a plurality of outer longitudinal reinforcements and a plurality of outer stirrups, and the plurality of outer longitudinal reinforcements are distributed in a rectangular structure, and the surfaces of the outer stirrups are connected to the outer longitudinal reinforcements.

[0010] Preferably, the column segment is a rectangular structure, which includes two segment units with rectangular cross-sections and a pair of longitudinal plates parallel to each other, and the two segment units are connected by a pair of longitudinal plates; the plate segment includes a pair of transverse plate groups, each transverse plate group is composed of a pair of transverse plate units parallel to each other; one side of the segment unit is connected to the transverse plate group, and the other side is connected to the longitudinal plate; the segment unit is provided with a plurality of reinforcing longitudinal ribs, and the plurality of reinforcing longitudinal ribs are connected by reinforcing stirrups.

[0011] Preferably, the first steel bar and the first prestressed steel bar are pre-embedded in the cast-in-place pedestal; the solid section of the pier bottom is provided with a first steel plate and a second steel bar; the bottom surface of the column segment located at the bottom of the prefabricated pier body is provided with a second steel plate, the first steel plate and the second steel plate are welded and connected, the first prestressed steel bar is connected to the prestressed coarse steel bar in the column segment located at the bottom of the prefabricated pier body; the first steel bar is connected to the second steel bar; the prefabricated pier body and the solid section of the pier bottom, and the prefabricated pier body and the cast-in-place pedestal are connected by cast-in-place concrete wet joints.

[0012] Preferably, the prestressed coarse steel bars in the column segment located at the top of the prefabricated pier body extend into the cap beam and are connected to the cap beam, and the third steel bars are embedded in the solid section of the pier top, and the third steel bars extend into the cap beam and are connected to the cap beam.

[0013] A lightweight assembled column-plate combined box-type high pier structure and its construction process include the following steps: Step 1: Cast the cap and embed the cap prestressed coarse steel bars, cast-in-place wet joint connecting steel bars and temporary connecting and fixing steel plates; Step 2: Install the first section of prestressed coarse steel bars and connect them to the embedded prestressed coarse steel bars using connectors; Step 3: Install the first section of the prefabricated column and adjust the positioning of the jack; Step 4: Weld and connect the fixed steel plates, remove the adjusting jacks, and install the prestressed thick steel pipe connection sleeves; Step 5: Install the first section of the precast plate (the pier bottom section) and weld the connecting angle steel; Step 6: Install the wet joint formwork and pour the wet joint concrete; Step 7: Install the second section of the prefabricated column and adjust the positioning of the jack; Step 8: Install the temporary fixing structure of the second segment of the precast column, weld the column-plate joint connection angle steel, and remove the jack; Step 9: Install the prestressed thick steel pipe connection sleeve, install the formwork, and cast the column segment joint and column-slab joint UHPC; Step 10: Install the second section of the precast panel and weld the column-panel joint connection angle steel; Step 11: Repeat steps 7 to 9 to install the third section of the precast column and cast the UHPC wet joint; Step 12: After the cast UHPC wet joint reaches the design strength, tension the prestressed coarse steel bars and anchor them; Step 13: Install the second section of prestressed thick steel bars; Step 14: Repeat steps 3 to 12 to install the remaining prefabricated pier segments until the last segment is installed and the prestressed coarse steel bars are anchored; Step 15: Install the bottom formwork of the wet-jointed solid section on the pier top, install the steel bars, and pour the solid section concrete; Step 16: Construct concrete cap beam.

[0014] Preferably, the column segments are installed by crane or tower crane, and the column segments are temporarily connected and fixed by bolt-locked H-shaped steel, which meets the stress and stability requirements during the construction stage, and can realize the tensioning and anchoring of prestressed coarse steel bars after the continuous construction of several column segments, thus shortening the construction period; The temporary H-shaped steel connection and fixing structure includes locking bolts, inner H-shaped steel and outer H-shaped steel. The inner H-shaped steel is arranged inside the column segment, and the outer H-shaped steel is arranged outside the column segment. Openings are reserved on the column segment for inserting locking bolts. After the locking bolts are pulled and anchored, the inner H-shaped steel and the outer H-shaped steel inside and outside the column segment are locked with the two adjacent column segments. Multiple pairs of inner H-shaped steel and outer H-shaped steel are arranged along the column segment to lock the column segments of the two adjacent piers to form a whole load-bearing structure, so as to ensure that the pier-column structure has sufficient bearing capacity and stability during the construction process before the joints of the column segments are constructed or do not reach sufficient strength.

[0015] Preferably, the UHPC wet joint casting formwork between the column segments adopts a unitized assembled formwork, and the unitized assembled formwork is positioned and fastened by a temporary connection fixing structure; and a grouting port is provided in the inner mold of the unitized assembled formwork.

[0016] The lightweight assembled column-slab combined box-type high pier structure and the construction process thereof provided by the present invention adopt UHPC wet joints, steel-UHPC combined wet joints and partially prestressed column segment joint technology, and multiple column segment continuous and rapid construction technology, thereby realizing lightweight assembled construction of the pier body. The structure has simple construction, convenient construction, good durability, good economy, energy saving and environmental protection, and has broad prospects for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a front cross-sectional view of the high pier structure of the present invention; Figure 2 It is a side cross-sectional view of the high pier structure of the present invention; Figure 3 It is a cross-sectional view of a column segment of a high pier structure of the present invention; Figure 4 It is a schematic diagram of the connection between the column segment and the cast-in-place cap of the high pier structure of the present invention; Figure 5 A schematic diagram of the connection between a column segment and a cast-in-place cap in another embodiment of the high pier structure of the present invention; Figure 6 is a cross-sectional view of a column segment of another embodiment of the high pier structure of the present invention; Figure 7 It is a schematic diagram of the connection structure between column segments of the high pier structure of the present invention; Figure 8 It is a schematic diagram of the connection structure between the column segment and the plate segment of the high pier structure of the present invention; Fig. 9 It is a schematic diagram of the connection structure between the column segment and the cast-in-place cap of the high pier structure of the present invention; Fig.10 It is a schematic diagram of the connection structure between the column segment and the cast-in-place cap beam of the high pier structure of the present invention; Fig.11 It is a schematic diagram of step 1 of the construction process of the present invention; Fig.12 It is a schematic diagram of step 2 of the construction process of the present invention; Fig.13 It is a schematic diagram of step three of the construction process of the present invention; Fig.14 It is a schematic diagram of step 4 of the construction process of the present invention; Fig.15 It is a schematic diagram of step 5 of the construction process of the present invention; Fig.16 It is a schematic diagram of step 6 of the construction process of the present invention; Fig.17 It is a schematic diagram of step seven of the construction process of the present invention; Fig.18 It is a schematic diagram of step eight of the construction process of the present invention; Fig.19 It is a schematic diagram of step nine of the construction process of the present invention; Fig. 20 It is a schematic diagram of step 10 of the construction process of the present invention; Fig.21 It is a schematic diagram of step eleven of the construction process of the present invention; Fig. 22 It is a schematic diagram of step 12 of the construction process of the present invention; Fig.23 It is a schematic diagram of step thirteen of the construction process of the present invention; Fig.24 It is a schematic diagram of step 14 of the construction process of the present invention; Fig.25 It is a schematic diagram of step 15 of the construction process of the present invention; Fig.26 It is a schematic diagram of step 16 of the construction process of the present invention; Fig. 27 It is a schematic diagram of the temporary connection and fixing structure of the H-beam of the present invention; Fig.28 It is a schematic diagram of the installation structure of an embodiment of the H-beam temporary connection and fixing structure of the present invention; The marks in the drawings are as follows: 1--cast-in-place foundation, 101--first steel bar, 102--first prestressed steel bar, 2--precast pier, 21--precast slab, 211--slab segment, 2111--transverse slab, 2112--transverse slab unit, 212--H-steel temporary connection fixing structure, 2121--locking bolt, 2122--inner H-steel, 2123--outer H-steel, 22--precast column, 221--pier top solid section, 2211--third steel bar, 222 --Solid section at the bottom of the pier, 2221--First steel plate, 2222--Second steel bar, 223--Column segment, 2231--Prestressed steel bar embedded pipe, 2232--Snap-on sleeve, 2233--Prestressed coarse steel bar, 2234--Connector, 2235--UHPC wet joint, 2236--Inner longitudinal bar, 2237--Inner stirrup, 2238--Outer longitudinal bar, 2239--Outer stirrup, 22310--Segment unit, 2231 1--Longitudinal plate, 22312--Reinforced longitudinal reinforcement, 22313--Reinforced stirrups, 22314--Second steel plate, 3--Cast-in-place cap beam, 4--Steel-UHPC combined wet joint, 41--Embedded channel steel, 42--Embedded steel sleeve, 43--Connecting angle steel, 44--Connecting steel bar, 441--Column side steel bar, 442--Slab side steel bar, 45--Cast-in-place UHPC, 5--Prestressed coarse steel bar for pedestal, 6--Temporary connection fixing steel plate, 7 --The first section of prestressed coarse steel bars, 8--The first section of precast column, 9--Jack, 10--The first section of precast slab, 11--Wet joint formwork, 12--Wet joint concrete, 13--The second section of precast column, 14--Temporary fixing structure of the second section, 15--The second section of precast slab, 16--The third section of precast column, 17--The second section of prestressed coarse steel bars, 18--The nth section of precast column, 19--Solid section concrete, 20--Concrete cap beam. DETAILED DESCRIPTION

[0019] The present invention discloses a lightweight assembled column-plate combined box-type high pier structure and a construction process thereof, which adopts UHPC wet joints, steel-UHPC combined wet joints and partially prestressed column segment joint technology, and multiple column segment continuous and rapid construction technology, thereby realizing lightweight assembled construction of the pier body. The structure has simple construction, convenient construction, good durability, good economy, energy saving and environmental protection, and has broad prospects for promotion and application.

[0020] The following is a clear and detailed description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] See also Figures 1 to 10 The present invention provides a lightweight assembled column-slab combined box-type high pier structure, comprising a cast-in-place cap 1, a prefabricated pier body 2 and a cast-in-place cap beam 3; the prefabricated pier body 2 comprises a prefabricated plate 21 and at least two prefabricated columns 22, the prefabricated plate 21 is arranged between two adjacent prefabricated columns 22, and its two sides are respectively connected to the two prefabricated columns 22; the prefabricated plate 21 is composed of a plurality of plate segments 211; the prefabricated column 22 comprises a pier top solid segment 221, a standard segment and a pier bottom solid segment 222; the standard segment is composed of a plurality of column segments 223; the pier top solid segment 221 is connected to the cast-in-place cap beam 3, and the pier bottom solid segment 222 is connected to the cast-in-place cap 1.

[0022] In an embodiment of the present invention, the lightweight assembled high pier structure is composed of a cast-in-place foundation 1, a prefabricated pier body 2 and a cast-in-place cap beam 3. The number of prefabricated columns 22 can be set according to actual needs, and can be two or four. Among them, the prefabricated pier body 2 includes a standard segment, which is the main part of the entire prefabricated pier body 2, and then a pier top solid segment 221 and a pier bottom solid segment 222 are respectively set at the top and bottom of the main part. The standard segment is composed of a number of column segments 223 prefabricated with concrete, and the cross-sectional form of the column segment 223 can be set to box-shaped and rectangular as needed. The column segment 223 of the box-shaped structure is arranged in the transverse bridge direction and combined with the transverse plate segment 211 to form a box-type structure; the column segment 223 of the rectangular structure is arranged in the transverse bridge direction and the longitudinal bridge direction, and a box-type structure is formed by the transverse plate segment 211 and the longitudinal connecting plate. In this embodiment, the plate segment 211 is also prefabricated with concrete, and multiple plate segments 211 are spliced ​​and spliced ​​with each other.

[0023] Through the above structural design, the most important standard segment in the entire prefabricated pier body 2 is split into multiple separate column segments 223, and the prefabricated plate 21 at the connection is also split into multiple plate segments 211, so that the volume and weight of the column segment 223 and the plate segment 211 are well controlled, and can be easily prefabricated in the factory, and can also be easily transported and handled. The multi-segment design enables the wide application of continuous and rapid construction technology. Temporary construction measures are used to meet the stress and stability requirements of each column segment 223 during the construction process. The construction of the column segment 223 does not need to wait for the joint material to reach the design strength, thereby realizing multi-segment continuous and rapid construction; after adopting the multi-segment continuous and rapid construction technology, more joints or seams can be set, thereby reducing the height of the prefabricated segment and the weight of the prefabricated component.

[0024] Preferably, the column segment 223 is provided with a plurality of prestressed steel bar embedded pipes 2231, and the prestressed steel bar embedded pipes 2231 on two adjacent column segments 223 are connected by a snap-fit ​​sleeve 2232; the prestressed steel bar embedded pipes 2231 are provided with prestressed coarse steel bars 2233, and the two adjacent prestressed coarse steel bars 2233 are connected by a connector 2234; and the two adjacent column segments 223 are connected by a UHPC wet joint 2235. In this embodiment, a plurality of prestressed steel bar embedded pipes 2231 are provided on the side wall of the column segment 223, and a prestressed coarse steel bar 2233 is provided in each prestressed steel bar embedded pipe 2231. Between two adjacent column segments 223, the prestressed steel bar embedded pipes 2231 on the two column segments 223 are arranged in a one-to-one matching manner, and the two relative prestressed steel bar embedded pipes 2231 are butt-jointed by a snap-fit ​​connection sleeve. The snap-fit ​​connection sleeve is easy to install and can quickly splice the two prestressed steel bar embedded pipes 2231. Before the sleeve connection, the prestressed coarse steel bars 2233 in the prestressed steel bar embedded pipe 2231 need to be butt-jointed with the prestressed coarse steel bars 2233 on the adjacent segment, and the two prestressed coarse steel bars 2233 are quickly butt-jointed using a connector 2234. In addition, the joints between the column segments 223 use UHPC wet joints 2235. UHPC materials have good compressive and tensile properties, bonding properties and working properties (good fluidity and self-compacting). The use of UHPC wet joints can effectively reduce the size of wet joints, significantly improve the force of the joints, and facilitate construction.

[0025] Furthermore, the present invention can reduce the tensile stress of the prestressed steel bars as much as possible under the premise that the prestressed steel bars reach yield at the ultimate bearing capacity state by adopting a reasonable prestressing force, thereby achieving both full utilization of the strength of the prestressed steel bar material and ensuring that the pier body has good ductility and seismic resistance.

[0026] Preferably, dry joints are used between two adjacent plate segments 211, and shear keys are provided to engage with each other; the plate segment 211 and the corresponding column segment 223 are staggered; the plate segment 211 and the corresponding column segment 223 are connected through a steel-UHPC combined wet joint 4; the steel-UHPC combined wet joint 4 includes an embedded channel steel 41, an embedded steel sleeve 42, a connecting angle steel 43, a connecting steel bar 44 and a cast-in-place UHPC; the embedded channel steel 41 is provided in the column segment 223, the embedded steel sleeve 42 is provided in the plate segment 211, the embedded channel steel 41 and the embedded steel sleeve 42 are connected through the connecting angle steel 43, the connecting steel bar 44 includes a column side steel bar 441 and a plate side steel bar 442, and the cast-in-place UHPC connects the column side steel bar 441 and the plate side steel bar 442. In this embodiment, a steel-UHPC combined wet joint 4 is used between the plate segments 211. The UHPC material has good compression resistance, tensile strength, bonding properties and working performance (good fluidity and self-compacting). The use of UHPC wet joints can effectively reduce the size of the wet joints, significantly improve the stress of the joints, and facilitate construction.

[0027] Preferably, the column segment 223 is a box-shaped structure, and its cross-section is a hollow rectangular structure; the plate segment 211 includes two mutually parallel transverse plates 2111, and the ends of the two transverse plates 2111 are connected to one side surface of the column segment 223; the prestressed steel embedded pipe 2231 is distributed at intervals along the side wall of the column segment 223, and the interior of the column segment 223 is provided with an inner reinforcement layer and an outer reinforcement layer; the inner reinforcement layer includes a plurality of inner longitudinal reinforcements 2236 and a plurality of inner hoop reinforcements 2237, and the plurality of inner longitudinal reinforcements 2236 are distributed in a rectangular shape, and the surfaces of the inner hoop reinforcements 2237 are connected to the inner longitudinal reinforcements 2236; the outer reinforcement layer includes a plurality of outer longitudinal reinforcements 2238 and a plurality of outer hoop reinforcements 2239, and the plurality of outer longitudinal reinforcements 2238 are distributed in a rectangular structure, and the surfaces of the outer hoop reinforcements 2239 are connected to the outer longitudinal reinforcements 2238.

[0028] In this embodiment, inner and outer reinforcement layers are respectively provided on the inner and outer sides of the column segment 223 to clamp the prestressed steel bar embedded pipe 2231 together, forming a three-layer structure, and concrete is poured between each layer. Through the above structural design, the structural strength of the column segment 223 is effectively improved, so that the hollow column segment 223 inside can also withstand greater pressure, so that the length of the column segment 223 is controlled, and it is more convenient to install and transport.

[0029] Preferably, the column segment 223 is a rectangular structure, which includes two segment units 22310 with rectangular cross-sections and a pair of longitudinal plates 22311 parallel to each other, and the two segment units 22310 are connected by a pair of longitudinal plates 22311; the plate segment 211 includes a pair of transverse plate groups, each transverse plate group is composed of a pair of transverse plate units 2112 parallel to each other; one side of the segment unit 22310 is connected to the transverse plate group, and the other side is connected to the longitudinal plate 22311; the segment unit 22310 is provided with a plurality of reinforcing longitudinal ribs 22312, and the plurality of reinforcing longitudinal ribs 22312 are connected by reinforcing stirrups 22313.

[0030] In this embodiment, the column segment 223 is formed by splicing a segment unit 22310 with a rectangular cross-section and a longitudinal plate 22311. The column segment 223 and the longitudinal plate 22311 enclose an internal hollow structure. The segment unit 22310 is a solid structure, and reinforcing longitudinal ribs 22312 are arranged inside to improve the structural strength. Horizontally arranged reinforcing stirrups 22313 are used between the reinforcing longitudinal ribs 22312 for further reinforcement.

[0031] Preferably, the cast-in-place foundation 1 is pre-embedded with a first steel bar 101 and a first prestressed steel bar 102; the solid section 222 of the pier bottom is provided with a first steel plate 2221 and a second steel bar 2222; a second steel plate 22314 is provided on the bottom surface of the column segment 223 located at the bottom of the prefabricated pier body 2, the first steel plate 2221 and the second steel plate 22314 are welded and connected, the first prestressed steel bar 102 is connected to the prestressed coarse steel bar 2233 in the column segment 223 located at the bottom of the prefabricated pier body 2; the first steel bar 101 is connected to the second steel bar 2222; the prefabricated pier body 2 and the solid section 222 of the pier bottom, as well as the prefabricated pier body 2 and the cast-in-place foundation 1 are connected by cast-in-place concrete wet joints.

[0032] Preferably, the prestressed coarse steel bars 2233 in the column segment 223 at the top of the precast pier body 2 extend into the cap beam to be connected to the cap beam, and the third steel bars 2211 are embedded in the solid segment 221 at the top of the pier, and the third steel bars 2211 extend into the cap beam to be connected to the cap beam. In this embodiment, the prestressed coarse steel bars 2233 on the column segment 223 at the top of the precast pier body 2 extend into the cap beam to be connected to the cap beam, and at the same time, the column segment 223 at the top of the precast pier body 2 is provided with a cast-in-place concrete wet-jointed solid segment, and the pre-embedded connecting steel bars 44 in the cast-in-place solid segment extend into the cap beam to be connected to the cap beam.

[0033] Please refer to Figures 11 to 28 A lightweight assembled column-plate combined box-type high pier structure and its construction process include the following steps: Step 1: Cast the cap and embed the cap prestressed coarse steel bars 5, cast-in-place wet joint connecting steel bars and temporarily connect the fixed steel plates 6; Step 2: Install the first section of prestressed coarse steel bars 7 and connect them to the embedded prestressed coarse steel bars using connectors; Step 3: Install the first section 8 of the prefabricated column and position and adjust the jack 9; Step 4: Weld and connect the fixed steel plates, remove the adjusting jack 9, and install the prestressed thick steel bar pipe connection sleeve; Step 5: Install the first section 10 (the pier bottom section) of the precast plate and weld the connecting angle steel; Step 6: Install the wet joint template 11 and pour the wet joint concrete 12; Step 7: Install the second section 13 of the prefabricated column and position and adjust the jack 9; Step 8: Install the temporary fixed structure of the second section 13 of the precast column, weld the column-plate joint connection angle steel, and remove the jack 9; Step 9: Install the prestressed thick steel pipe connection sleeve, install the formwork, and cast the column segment joint and column-slab joint UHPC; Step 10: Install the second section 15 of the precast panel and weld the angle steel of the column-panel joint; Step 11: Repeat steps 7 to 9 to install the third section 16 of the precast column and cast the UHPC wet joint; Step 12: After the cast UHPC wet joint reaches the design strength, tension the prestressed coarse steel bars and anchor them; Step 13: Install the second section of prestressed thick steel bars 17; Step 14: Repeat steps 3 to 12 to install the remaining prefabricated pier segments until the last segment is installed and the prestressed coarse steel bars are anchored; Step 15: Install the bottom formwork of the wet-jointed solid section of the pier top, install the steel bars, and pour the solid section concrete 19; Step 16: Construct concrete cap beam.

[0034] The construction process of the present invention has the advantages of convenient construction, good stress performance, good durability, good economy, energy saving and environmental protection, etc., and is particularly suitable for high pier bridges in mountainous areas. This construction process adopts UHPC wet joint technology. UHPC materials have good compression resistance, tensile resistance, bonding performance and working performance (good fluidity and self-compacting). The use of UHPC wet joints can effectively reduce the size of wet joints, significantly improve the stress of joints, and facilitate construction.

[0035] In addition, by adopting a reasonable prestressing force, the prestressing stress of the prestressed steel bars is reduced as much as possible under the premise that the prestressed steel bars reach yield under the ultimate bearing capacity state, so as to fully exert the strength of the prestressed steel bars and ensure that the pier body has good ductility and seismic performance. Finally, in terms of improving the construction speed, the rapid construction technology of multi-segment splicing and installation is adopted. Through temporary construction measures, the stress and stability requirements of the pier body segments installed during the construction process are met. The segment construction does not need to wait for the joint material to reach the design strength, thereby realizing multi-segment continuous and rapid construction; after adopting the multi-segment continuous and rapid construction technology, more joints can be set on the pier body, thereby reducing the height of the prefabricated segments and the weight of the prefabricated components.

[0036] The lightweight assembled high pier structure of the present invention is composed of a cast-in-place cap, a prefabricated pier body and a cast-in-place cap beam. The pier body is composed of a plurality of prefabricated concrete columns and plate segments spliced ​​together to form an integral box-type structure. The cross-sectional forms of the prefabricated columns are box-shaped and rectangular. The box-shaped columns are arranged in the transverse direction of the bridge and are combined with the transverse plate to form a box-type structure. The rectangular columns are arranged in the transverse and longitudinal directions of the bridge and are formed into a box-type structure through the transverse plate and the longitudinal plate. The prefabricated column segments are connected by UHPC wet joints, and through-through prestressed coarse steel bars are arranged to strengthen the connection between the segments and improve the bearing capacity of the pier body. For the box-shaped columns, prestressed coarse steel bar bundles can be arranged according to the force requirements to increase the cross-sectional reinforcement ratio and thus improve the bearing capacity of the bridge pier. Dry joints are used between the prefabricated plate segments, and shear keys are arranged to engage with each other. The column-plate joint adopts a steel-UHPC combined wet joint to improve the bearing capacity of the node and facilitate construction. The pier body and the cap are connected by cast-in-place concrete wet joints, and connecting steel bars and prestressed coarse steel bars are pre-embedded in the pile foundation or the cap. The prestressed coarse steel bars of the precast pier top segment are all extended into the cap beam to be connected with the cap beam. At the same time, a cast-in-place concrete wet-jointed solid section is arranged in the precast pier column top segment. The pre-embedded connecting steel bars in the cast-in-place solid section are extended into the cap beam to be connected with the cap beam.

[0037] Preferably, the column segments 223 are installed by cranes or tower cranes, and a bolt-locked H-shaped steel temporary connection fixing structure 212 is used between the column segments 223 to meet the stress and stability requirements during the construction phase, and to achieve the tensioning and anchoring of the prestressed coarse steel bars 2233 after the continuous construction of several column segments 223, thereby shortening the construction period; the H-shaped steel temporary connection fixing structure 212 includes a locking bolt 2121, an inner H-shaped steel 2122 and an outer H-shaped steel 2123, wherein the inner H-shaped steel 2122 is arranged inside the column segment 223, and the outer H-shaped steel 2123 is arranged outside the column segment 223 outside; the column segment 223 is reserved with openings for inserting locking bolts 2121. After the locking bolts 2121 are pulled and anchored, the inner H-shaped steel 2122 and the outer H-shaped steel 2123 inside and outside the column segment 223 are locked with the two adjacent column segments 223. Multiple pairs of inner H-shaped steels 2122 and outer H-shaped steels 2123 are arranged along the column segment 223 to lock the column segments 223 of the two adjacent piers to form a whole force, and before the joints of the column segment 223 are not constructed or have not reached sufficient strength, it is ensured that the pier structure has sufficient bearing capacity and stability during the construction process. In this embodiment, the column segment 223 and the plate segment 211 are installed by a car crane or a tower crane. The box-shaped column segments 223 are temporarily connected and fixed by H-shaped steel (removed and reused), and the rectangular column segments 223 are temporarily fixed by welding with embedded steel plates (not removed). The temporary fixing measures meet the force and stability requirements during the construction stage.

[0038] Preferably, the UHPC wet joint casting template between the column segments 223 adopts a unitized assembled template, and the unitized assembled template is positioned and fastened by a temporary connection fixing structure; the inner mold of the unitized assembled template is provided with a grouting port The assembled partially prestressed concrete column-slab combined high pier structure of the present invention has simple structure, reliable force, high bearing capacity, good seismic performance, material saving, light component weight (single component does not exceed 15 tons), can be installed and constructed by crane or tower crane, simple connection and easy construction, and short construction period. The present invention has the advantages of simple and reliable structure, material saving, convenient construction, energy saving and environmental protection, etc. It is suitable for high piers of bridges with a pier height of less than 100 meters, and has more significant advantages for highway bridges in mountainous areas with complex terrain.

[0039] The lightweight assembled column-slab combined box-type high pier structure and the construction process thereof provided by the present invention adopt UHPC wet joints, steel-UHPC combined wet joints and partially prestressed column segment joint technology, and multiple column segment continuous and rapid construction technology, thereby realizing lightweight assembled construction of the pier body. The structure has simple construction, convenient construction, good durability, good economy, energy saving and environmental protection, and has broad prospects for promotion and application.

Claims

1. A lightweight assembled column-plate combined box-type high pier structure, characterized in that: The invention comprises a cast-in-place foundation (1), a prefabricated pier body (2) and a cast-in-place cap beam (3); the prefabricated pier body comprises a prefabricated plate (21) and at least two prefabricated columns (22); the prefabricated plate is arranged between two adjacent prefabricated columns, and its two sides are respectively connected to the two prefabricated columns; the prefabricated plate is composed of a plurality of plate segments (211) spliced ​​together; the prefabricated column comprises a pier top solid segment (221), a standard segment and a pier bottom solid segment (222); the standard segment is composed of a plurality of column segments (223) spliced ​​together; the pier top solid segment is connected to the cast-in-place cap beam, and the pier bottom solid segment is connected to the cast-in-place foundation.

2. The lightweight assembled column-plate combined box-type high pier structure according to claim 1 is characterized in that: The column segment is provided with a plurality of prestressed steel bar embedded pipes (2231), and the prestressed steel bar embedded pipes on two adjacent column segments are connected via a snap-fit ​​sleeve (2232); prestressed coarse steel bars (2233) are arranged in the prestressed steel bar embedded pipes, and two adjacent prestressed coarse steel bars are connected via a connector (2234); and two adjacent column segments are connected via a UHPC wet joint (2235).

3. The lightweight assembled column-plate combined box-type high pier structure according to claim 2 is characterized in that: A dry joint is used between two adjacent plate segments, and a shear key is arranged to be interlocked and connected with each other; the plate segment and the corresponding column segment are staggered and matched; the plate segment and the corresponding column segment are connected through a steel-UHPC combined wet joint (4); the steel-UHPC combined wet joint includes a pre-buried channel steel (41), a pre-buried steel sleeve (42), a connecting angle steel (43), a connecting steel bar (44) and a cast-in-place UHPC; the pre-buried channel steel is arranged in the column segment, the pre-buried steel sleeve is arranged in the plate segment, the pre-buried channel steel and the pre-buried steel sleeve are connected through the connecting angle steel, the connecting steel bar includes a column side steel bar (441) and a plate side steel bar (442), and the cast-in-place UHPC connects the column side steel bar and the plate side steel bar.

4. The lightweight assembled column-plate combined box-type high pier structure according to claim 2 is characterized in that: The column segment is a box-shaped structure, and its cross-section is a hollow rectangular structure; the plate segment includes two mutually parallel transverse plates (2111), and the ends of the two transverse plates are connected to one side surface of the column segment; the prestressed steel bar embedded pipeline is distributed along the side wall of the column segment at intervals, and the interior of the column segment is provided with an inner reinforcement layer and an outer reinforcement layer; the inner reinforcement layer includes a plurality of inner longitudinal reinforcements (2236) and a plurality of inner stirrups (2237), and the plurality of inner longitudinal reinforcements are distributed in a rectangular shape, and the surfaces of the inner stirrups are connected to the inner longitudinal reinforcements; the outer reinforcement layer includes a plurality of outer longitudinal reinforcements (2238) and a plurality of outer stirrups (2239), and the plurality of outer longitudinal reinforcements are distributed in a rectangular structure, and the surfaces of the outer stirrups are connected to the outer longitudinal reinforcements.

5. The lightweight assembled column-plate combined box-type high pier structure according to claim 2 is characterized in that: The column segment is a rectangular structure, which includes two segment units (22310) with rectangular cross-sections and a pair of longitudinal plates (22311) parallel to each other, and the two segment units are connected by a pair of longitudinal plates; the plate segment includes a pair of transverse plate groups, each transverse plate group is composed of a pair of transverse plate units (2112) parallel to each other; one side of the segment unit is connected to the transverse plate group, and the other side is connected to the longitudinal plate; the segment unit is provided with a plurality of reinforcing longitudinal ribs (22312), and the plurality of reinforcing longitudinal ribs are connected by reinforcing stirrups (22313).

6. The lightweight assembled column-plate combined box-type high pier structure according to claim 2 is characterized in that: The first steel bar (101) and the first prestressed steel bar (102) are pre-embedded in the cast-in-place pedestal; the solid section of the pier bottom is provided with a first steel plate (2221) and a second steel bar (2222); the bottom surface of the column segment at the bottom of the prefabricated pier body is provided with a second steel plate (22314), the first steel plate and the second steel plate are welded and connected, the first prestressed steel bar is connected to the prestressed coarse steel bar in the column segment at the bottom of the prefabricated pier body; the first steel bar is connected to the second steel bar; the prefabricated pier body and the solid section of the pier bottom, and the prefabricated pier body and the cast-in-place pedestal are connected by cast-in-place concrete wet joints.

7. The lightweight assembled column-plate combined box-type high pier structure according to claim 1 is characterized in that: The prestressed coarse steel bars in the column segment located at the top of the prefabricated pier body extend into the cap beam and are connected to the cap beam, and the third steel bars (2211) are embedded in the solid section of the pier top, and the third steel bars extend into the cap beam and are connected to the cap beam.

8. The lightweight assembled column-plate combined box-type high pier structure and its construction process according to any one of claims 1 to 7, characterized in that: The following steps are included: Step 1: Casting the cap and pre-embedding the cap prestressed coarse steel bars (5), cast-in-place wet joint connecting steel bars and temporary connecting and fixing steel plates (6); Step 2: installing the first section of prestressed coarse steel bars (7), and connecting them to the pre-buried cap prestressed coarse steel bars using connectors; Step 3: Install the first section (8) of the prefabricated column and adjust the positioning of the jack (9); Step 4: Weld and connect the fixed steel plates, remove the adjusting jacks, and install the prestressed thick steel pipe connection sleeves; Step 5: Install the first section (10) of the precast plate (the pier bottom section) and weld the connecting angle steel; Step 6: Install the wet joint formwork (11) and pour the wet joint concrete (12); Step 7: Install the second section (13) of the prefabricated column and adjust the positioning of the jack; Step 8: Install the temporary fixing structure of the second segment of the precast column (14), weld the column-plate joint connection angle steel, and remove the jack; Step 9: Install the prestressed thick steel pipe connection sleeve, install the formwork, and cast the column segment joint and column-slab joint UHPC; Step 10: Install the second section of the precast panel (15) and weld the column-panel joint connection angle steel; Step 11: Repeat steps 7 to 9 to install the third section of the precast column (16) and cast the UHPC wet joint; Step 12: After the cast UHPC wet joint reaches the design strength, tension the prestressed coarse steel bars and anchor them; Step 13: Install the second section of prestressed thick steel bars (17); Step 14: Repeat steps 3 to 12 to install the remaining prefabricated pier segments until the last segment is installed and the prestressed coarse steel bars are anchored; Step 15: Install the bottom formwork of the wet-jointed solid section of the pier top, install the steel bars, and pour the solid section concrete (19); Step 16: Construct concrete cap beam.

9. The lightweight assembled column-plate combined box-type high pier structure and its construction process according to claim 8 is characterized in that: The column segments are installed by crane or tower crane, and the column segments are temporarily connected and fixed by bolt-locked H-shaped steel (212), which meets the stress and stability requirements during the construction stage. It is possible to tension and anchor the prestressed coarse steel bars after the continuous construction of several column segments, thus shortening the construction period. The H-shaped steel temporary connection fixing structure comprises a locking bolt (2121), an inner H-shaped steel (2122) and an outer H-shaped steel (2123), wherein the inner H-shaped steel is arranged inside the column segment and the outer H-shaped steel is arranged outside the column segment; a hole is reserved on the column segment for inserting the locking bolt, and after the locking bolt is pulled and anchored, the inner H-shaped steel and the outer H-shaped steel inside and outside the column segment are locked with the two adjacent column segments, and multiple pairs of inner H-shaped steel and outer H-shaped steel are arranged along the column segment to lock the column segments of the two adjacent piers to form a whole load-bearing structure, so as to ensure that the pier column structure has sufficient bearing capacity and stability during the construction process before the joint of the column segment is not constructed or does not reach sufficient strength.

10. The lightweight assembled column-plate combined box-type high pier structure and its construction process according to claim 8 is characterized in that: The UHPC wet joint casting formwork between the column segments adopts a unitized assembled formwork, and the unitized assembled formwork is positioned and fastened by a temporary connection fixing structure; the inner mold of the unitized assembled formwork is provided with a grouting port.

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