Lightweight fabricated column-plate combined truss type ultrahigh pier structure and construction process thereof

Abstract

The invention discloses a light-weight assembly type column and plate combined truss type ultrahigh pier structure and a construction process thereof, based on an existing prefabricated pier technology, the stress performance of the structure is improved by adopting UHPC wet joints, profile steel-UHPC wet joints and a partial prestress technology, and construction is facilitated; a multi-section continuous and rapid construction technology is provided, the height of the prefabricated sections is reduced, and therefore the self weight of the prefabricated parts is obviously reduced, transportation and rapid installation are greatly facilitated, and the construction period is shortened. Compared with a conventional cast-in-place ultrahigh pier, the light-weight assembly type partially-prestressed concrete column plate combined truss type ultrahigh pier structure has the advantages that the material consumption is reduced, and the construction cost is lower. The lightweight assembly type partially prestressed concrete column plate combined truss type ultrahigh pier structure and the construction technology thereof have the advantages of being convenient to construct, good in stress performance, durability and economy, capable of saving energy, environmentally friendly and the like, are suitable for bridge ultrahigh pier assembly construction and have wide application and popularization prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering, and more specifically, to a lightweight assembled column-slab combined truss-type super-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 concepts of safety, durability, energy conservation and environmental protection proposed by the country, 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. At present, the prefabrication and assembly technology of bridge superstructures in my country is relatively mature, and the superstructures of small and medium-span bridges are basically constructed by assembly. For the substructure, prefabrication and assembly technology is in the exploratory stage. Some urban bridges, cross-sea bridges and highway bridges with conditions have gradually carried out the application and research of prefabricated assembly pier technology. However, given the current technology, prefabricated prefabricated piers are basically used for shorter piers and cannot be promoted to high piers. It is even more difficult for super-high piers, and the cost of prefabricated piers is generally higher than that of cast-in-place piers.

[0003] The main technical limitations are: 1) The joint structure is complex or difficult to construct, so the design generally minimizes the number of 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 super-high pier bridges in mountainous areas. 2) To ensure that the pier body is reliable, most prefabricated piers currently use dry joints or adhesive joints, and grouting sleeves to connect steel bars. This technology requires precise segment docking, and the segments are required to be matched and prefabricated, which has high construction requirements. In particular, it is difficult to control the verticality of the super-high 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 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 continuous force of the pier body is achieved by relying on the bonding of cast-in-place joint materials (concrete or UHPC, etc.) and steel bars. The stress performance is relatively poor. For super-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, the material consumption is large, and the project cost is increased. 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 super-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; 5) For super-high piers, as the height of the pier increases, the wind load effect becomes more significant, and the seismic problem becomes more prominent, which is a huge problem of structural safety and reliability of the prefabricated structure of the base.

[0004] 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

[0005] The present invention discloses a lightweight assembled column-plate combined truss-type super-high pier structure, comprising a base, a pier body and a cap beam which are sequentially connected from bottom to top; the pier body comprises a prefabricated column, a prefabricated plate and a prefabricated truss; the cross-section of the prefabricated column is a rectangular structure; two of the prefabricated columns on the front and rear sides along the bridge direction and two of the prefabricated plates form a box-shaped combined structure, and two adjacent box-shaped combined structures are connected with the prefabricated truss in the transverse direction of the bridge to form a truss structure.

[0006] Preferably, the two prefabricated columns on the front and rear sides along the bridge direction are symmetrically and inwardly arranged, and the length of the box-shaped combined structure along the bridge direction gradually changes along the height direction to form a structure that is wider at the bottom and narrower at the top.

[0007] Preferably, the prefabricated column is composed of a plurality of column segments, and adjacent column segments are connected by UHPC wet joints; a through prestressed coarse steel bar embedded pipe is provided in the column segment, and adjacent prestressed coarse steel bar embedded pipes are connected by snap-on sleeves; prestressed coarse steel bars are provided in the prefabricated column, and the prestressed coarse steel bars pass through the prestressed coarse steel bar embedded pipe; the ends of the prestressed coarse steel bars are connected with extended coarse steel bars, and the prestressed coarse steel bars and the extended coarse steel bars are connected by connectors.

[0008] Preferably, the prefabricated truss is a prestressed concrete structure, and the end of the prefabricated truss is provided with a steel sleeve and a truss connecting steel bar, and is connected to the prefabricated column through the steel sleeve and the truss connecting steel bar.

[0009] Preferably, the prefabricated panel is composed of a plurality of panel segments, dry joints are used between adjacent panel segments, and shear keys are arranged to engage with each other; a steel-UHPC combined wet joint is used between the prefabricated column and the prefabricated panel, and between the prefabricated column and the prefabricated truss, and the steel-UHPC combined wet joint is composed of embedded channel steel, embedded steel sleeve, connecting angle steel, embedded connecting steel bar and cast-in-place UHPC.

[0010] Preferably, the pier body and the base are connected by a cast-in-place concrete wet joint, and cast-in-place wet joint connecting steel bars and pier bottom thick steel bars are provided in the base.

[0011] Preferably, a cast-in-place concrete wet-jointed solid section is provided in the column segment located at the top, and pier top connecting steel bars are pre-embedded in the cast-in-place concrete wet-jointed solid section; the prestressed coarse steel bars in the column segment located at the top and the pier top connecting steel bars extend into the cap beam and are connected to the cap beam.

[0012] Preferably, the column segments are provided with embedded steel plates, and the embedded steel plates between adjacent column segments are welded and connected.

[0013] Preferably, grouting holes are provided in the column segments; unitized assembly formwork is provided between adjacent column segments, and the unitized assembly formwork is connected to adjacent plate segments.

[0014] A construction process of a lightweight assembled column-slab combined truss-type super-high pier structure includes the following steps: Step 1: Cast the base and pre-embed the thick steel bars at the bottom of the pier, cast-in-place wet joint connecting steel bars and temporarily connect and fix the steel plates; Step 2: Install the prestressed thick steel bars and connect them with the embedded thick steel bars at the bottom of the pier using connectors; Step 3: Install the first column segment at the bottom of the prefabricated column and use a jack to position and adjust it; Step 4: Weld and connect the fixed steel plates, remove the adjustment jacks, and install the snap-on sleeves of the prestressed thick steel bar embedded pipes; Step 5: Install the first plate segment of the precast plate and weld the connecting angle steel; Step 6: Install the wet joint formwork and pour the wet joint concrete; Step 7: Install the second column segment of the prefabricated column and use a jack to position and adjust it; Step 8: Weld and connect the fixed steel plates, remove the adjustment jacks, and install the snap-on sleeves of the prestressed thick steel bar embedded pipes; Step 9: Install the prefabricated trusses connecting the first column segment and the second column segment of the prefabricated column, and weld the connecting angle steels; Step 10: Install the formwork, cast the column segment joints, column-slab joints, and precast column first segment column truss joints UHPC; Step 11: Install the second column segment of the precast panel and weld the connecting angle steel; Step 12: According to Step 7 to Step 11, install the third column segment of the precast column, cast the UHPC wet joint, and install the third slab segment of the precast slab; Step 13: Install the prefabricated truss between the second and third column segments of the prefabricated column, and the UHPC column-truss joint of the second column segment of the prefabricated column; Step 14: After the cast UHPC wet joint reaches the design strength, tension the prestressed coarse steel bars and anchor them; Step 15: Install the extended thick steel bars; Step 16: Install the remaining pier segments according to Steps 3 to 14 until the installation of the last segment and the anchoring of the extended thick steel bars are completed; Step 17: Install the bottom formwork of the wet-jointed solid section of the pier top, install the steel bars, and pour the solid section concrete; Step 18: Cast the cap beam.

[0015] Beneficial effects of the present invention: The lightweight assembled column-slab combined truss super-high pier structure and its construction process provided by the present invention adopt UHPC wet joints, steel-UHPC combined wet joints and partially prestressed segment joint technology, and multi-segment continuous rapid construction technology, thereby realizing lightweight assembled construction of the pier body; the width of the cross-bridge section is changed from large to small by inclination of the prefabricated columns, thereby reducing the wind load in the transverse direction of the bridge; the wind load in the cross-bridge direction is reduced by adopting a truss structure; the cross-bridge wind load is increased by arranging the prestressed steel bar bundles, thereby increasing the cross-sectional reinforcement ratio and the structural bearing capacity. The structure is simple in structure, convenient in construction, good in durability, good in economy, energy-saving and environmentally friendly, and has broad prospects for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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.

[0017] Figure 1 It is a front view of the lightweight assembled column-slab combined truss-type super-high pier structure of the present invention; Figure 2 It is a side view of the lightweight assembled column-slab combined truss-type super-high pier structure of the present invention; Figure 3 It is a cross-sectional view of the lightweight assembled column-slab combined truss-type super-high pier structure of the present invention; Figure 4 A cross-sectional view of a column segment of a lightweight assembled column-plate combined truss-type super-high pier structure of the present invention; Figure 5 It is a cross-sectional view of another side of a column segment of the lightweight assembled column-plate combined truss-type super-high pier structure of the present invention; Figure 6 It is a schematic diagram of the column segment connection structure of the lightweight assembled column-plate combined truss type super-high pier structure of the present invention; Figure 7 A cross-sectional view of a plate segment of a lightweight assembled column-plate combined truss-type super-high pier structure of the present invention; Figure 8 It is a cross-sectional view of another side of a plate segment of the lightweight assembled column-plate combined truss-type super-high pier structure of the present invention; Fig. 9 It is a cross-sectional view of the connection structure between the column segment and the plate segment; Fig.10 This is a cross-sectional view of the connection structure between the column segment and the prefabricated truss; Fig.11 Another angled cross-sectional view of the connection structure between the column segment and the prefabricated truss; Fig.12 This is the cross-sectional view of the connection structure between the prefabricated column and the base; Fig.13 This is the cross-sectional view of the connection structure between the prefabricated column and the cap; Fig.14 It is a schematic diagram of step 1 of the construction process of the present invention; Fig.15 It is a schematic diagram of step 2 of the construction process of the present invention; Fig.16 It is a schematic diagram of step three of the construction process of the present invention; Fig.17 It is a schematic diagram of step 4 of the construction process of the present invention; Fig.18 It is a schematic diagram of step 5 of the construction process of the present invention; Fig.19 It is a schematic diagram of step 6 of the construction process of the present invention; Fig. 20 It is a schematic diagram of step seven of the construction process of the present invention; Fig.21 It is a schematic diagram of step eight of the construction process of the present invention; Fig. 22 It is a schematic diagram of step nine of the construction process of the present invention; Fig.23 It is a schematic diagram of step 10 of the construction process of the present invention; Fig.24 It is a schematic diagram of step eleven of the construction process of the present invention; Fig.25 It is a schematic diagram of step 12 of the construction process of the present invention; Fig.26 It is a schematic diagram of step thirteen of the construction process of the present invention; Fig. 27 It is a schematic diagram of step 14 of the construction process of the present invention; Fig.28 It is a schematic diagram of step 15 of the construction process of the present invention; Fig.29 It is a schematic diagram of step 16 of the construction process of the present invention; Fig.30 It is a schematic diagram of step seventeen of the construction process of the present invention; Fig.31 It is a schematic diagram of step 18 of the construction process of the present invention; The marks in the drawings are as follows: 1--base, 11--cast-in-place wet joint connecting steel bars, 12--pier bottom thick steel bars, 13--fixed end anchors, 14--cast-in-place joint solid sections, 2--pier body, 21--precast columns, 211--column segments, 212--UHPC wet joint connections, 213--prestressed thick steel bar embedded pipes, 214--snap-on sleeves, 215--prestressed thick steel bars, 216--extended thick steel bars, 217--connectors, 218--prestressed thick steel bar bundle pipes, 219--prestressed thick steel bar bundles, 2110--vertical bars, 2111--hoops reinforcement, 2112--cast-in-place concrete wet joint solid section, 2113--pier top connecting reinforcement, 22--precast slab, 221--slab segment, 222--shear key, 223--steel-UHPC combined wet joint, 2231--embedded channel steel, 2232--embedded steel sleeve, 2233--connecting angle steel, 2234--embedded connecting reinforcement, 2235--cast-in-place UHPC, 224--longitudinal connecting reinforcement, 225--transverse connecting reinforcement, 23--precast truss, 231--steel sleeve, 232--truss connecting reinforcement, 3--cap beam. DETAILED DESCRIPTION

[0018] The invention discloses a lightweight assembled column-slab combined truss-type super-high pier structure and a construction process thereof. The structure has the advantages of simple construction, convenient construction, good durability, good economy, energy saving and environmental protection, and has broad prospects for promotion and application.

[0019] 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.

[0020] See also Figures 1 to 13 The present invention provides a lightweight assembled column-plate combined truss-type super-high pier structure, comprising a base 1, a pier body 2 and a cap beam 3 connected in sequence from bottom to top; the pier body 2 comprises a prefabricated column 21, a prefabricated plate 22 and a prefabricated truss 23; the cross-section of the prefabricated column 21 is a rectangular structure; the two prefabricated columns 21 on the front and rear sides along the bridge direction and the two prefabricated plates 22 form a box-shaped combined structure, and two adjacent box-shaped combined structures are connected to the prefabricated truss 23 in the transverse direction of the bridge to form a truss structure.

[0021] In the embodiment of the present invention, the lightweight assembled column-plate combined truss super-high pier structure is composed of a base 1, a pier body 2 and a cap beam 3, wherein the pier body 2 includes prefabricated columns 21, prefabricated panels 22 and prefabricated trusses 23. The number of pier bodies 2 can be set according to actual needs and can be one or more. In each pier body 2, four prefabricated columns 21, four prefabricated panels 22 and a plurality of prefabricated trusses 23 are included. For details, please refer to Figures 1 to 3 The two prefabricated columns 21 and the two prefabricated panels 22 on the front and rear sides along the bridge direction form a box-shaped composite structure, and the two adjacent box-shaped composite structures are connected with the prefabricated trusses 23 in the transverse direction of the bridge to form a truss structure. Figures 1 to 3 One side of the prefabricated column 21 is connected to the prefabricated plate 22, and the other side is connected to the prefabricated truss 23. The prefabricated truss 23 is inclined and connected in a staggered manner to reduce the wind load along the bridge.

[0022] Preferably, the two prefabricated columns 21 on the front and rear sides along the bridge direction are symmetrical and inwardly arranged, and the length of the box-shaped combined structure along the bridge direction gradually changes along the height direction, forming a structure that is wide at the bottom and narrow at the top. In this embodiment, the prefabricated columns 21 are inwardly inclined to form a cross-sectional width along the bridge direction that changes from large to small, thereby reducing the wind load in the transverse direction of the bridge.

[0023] Preferably, the prefabricated column 21 is composed of a plurality of column segments 211, and adjacent column segments 211 are connected by UHPC wet joints 212; a through prestressed coarse steel bar embedded pipe 213 is provided in the column segment 211, and adjacent prestressed coarse steel bar embedded pipes 213 are connected by snap-on sleeves 214; a prestressed coarse steel bar 215 is provided in the prefabricated column 21, and the prestressed coarse steel bar 215 passes through the prestressed coarse steel bar embedded pipe 213; the end of the prestressed coarse steel bar 215 is connected with an extended coarse steel bar 216, and the prestressed coarse steel bar 215 and the extended coarse steel bar 216 are connected by a connector 217. Through the above structural design, the cast-in-place column structure in the traditional structure is split into a plurality of separate column segments 211, so that the volume and weight of the column segment 211 are well controlled, and it can be easily prefabricated in the factory and conveniently transported. The multi-segment design enables the continuous and rapid construction technology to be widely used. In this embodiment, a prestressed coarse steel bar embedded pipe 213 is reserved in the column segment 211, and the two prestressed coarse steel bar embedded pipes 213 between two adjacent column segments 211 are butted, and a snap-on sleeve 214 that can be quickly installed is used for connection. After each column segment 211 is butted in place, all the prestressed coarse steel bar embedded pipes 213 are also connected into a long pipe, providing installation space for the prestressed coarse steel bar 215 and the extended coarse steel bar 216. The prestressed coarse steel bar 215 and the extended coarse steel bar 216 can be selected according to the actual construction height. When the height of the pier body 2 is not high, a single prestressed coarse steel bar 215 can be used. When the height of the pier body 2 is high, the prestressed coarse steel bar 215 and the extended coarse steel bar 216 can be connected to extend the length of the steel bar. When the prestressed coarse steel bar 215 and the extended coarse steel bar 216 are butted, a connector 217 can be used for butt connection. The connector 217 is a connecting mechanism for connecting steel bars, and the two steel bars can be quickly butted. Through the improvement of the above-mentioned structure and construction method, the requirements for transportation, connection, force and stability of each column segment 211 during the construction process can be well met. The construction of the column segment 211 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] Furthermore, a large-diameter prestressed coarse steel bar bundle pipe 218 may be provided in the column segment 211 , and a prestressed coarse steel bar bundle 219 composed of a plurality of steel bars may be installed in the pre-buried prestressed coarse steel bar bundle pipe 218 .

[0025] Furthermore, a plurality of vertical ribs 2110 may be disposed inside the column segment 211 , and stirrups 2111 may be disposed around the plurality of vertical ribs 2110 for reinforcement to improve the structural strength.

[0026] Preferably, the prefabricated truss 23 is a prestressed concrete structure, and the end of the prefabricated truss 23 is provided with a steel sleeve 231 and a truss connecting steel bar 232, and is connected to the prefabricated column 21 through the steel sleeve 231 and the truss connecting steel bar 232. In this embodiment, the prefabricated truss 23 is a prestressed concrete structure, and the end is provided with a steel sleeve 231 and a truss connecting steel bar to connect with the prefabricated column 21.

[0027] Preferably, the prefabricated panel 22 is composed of a plurality of panel segments 221, and dry joints are used between adjacent panel segments 221, and shear keys 222 are provided to engage with each other; a steel-UHPC composite wet joint 223 is used between the prefabricated column 21 and the prefabricated panel 22, and between the prefabricated column 21 and the prefabricated truss, and the steel-UHPC composite wet joint 223 is composed of embedded channel steel 2231, embedded steel sleeve 2312, connecting angle steel 2233, embedded connecting steel bar 2234 and cast-in-place UHPC 2235. Through the above structural design, the cast-in-place plate structure in the traditional structure is split into a plurality of separate panel segments 221, so that the volume and weight of the panel segments 221 are well controlled, and can be easily prefabricated in the factory, and can also be easily transported and handled. At the same time, in order to improve the connection strength between the plate segments 221, the present embodiment sets a shear key 222 on the plate segment 221, and the stability is improved by the mutual engagement of the shear key 222. The butt joint between the prefabricated column 21 and the prefabricated plate 22 adopts a steel-UHPC composite wet joint 223, and the prefabricated column 21 and the prefabricated truss also adopt a steel-UHPC composite wet joint 223. The steel-UHPC composite wet joint 223 is composed of embedded channel steel 2231, embedded steel sleeve 2312, connecting angle steel 2233, embedded connecting steel bar 2234 and cast-in-place UHPC 2235. The node is jointly stressed by steel components, UHPC and embedded connecting steel bar 2234, and has reliable and good bearing performance. At the same time, the construction is convenient and fast.

[0028] Furthermore, crisscrossed longitudinal connecting ribs 224 and transverse connecting ribs 225 are provided inside the prefabricated panel 22 to enhance the structural strength of the prefabricated panel 22 .

[0029] Preferably, the pier body 2 and the base 1 are connected by a cast-in-place concrete wet joint, and the base 1 is provided with cast-in-place wet joint connecting steel bars 11 and pier bottom thick steel bars 12. In this embodiment, the base 1 reserves cast-in-place wet joint connecting steel bars 11 and pier bottom thick steel bars 12 for docking with the pier body 2, and a fixed end anchor 13 is provided at the bottom of the pier bottom thick steel bars 12. After docking, cast-in-place concrete is used to fix them to form a solid cast-in-place joint solid section 14.

[0030] Preferably, a cast-in-place concrete wet-jointed solid section 2112 is provided in the column segment 211 at the top, and a pier top connecting steel bar 2113 is pre-embedded in the cast-in-place concrete wet-jointed solid section 2112; the prestressed coarse steel bars 215 in the column segment 211 at the top and the pier top connecting steel bars 2113 extend into the cap beam 3 and are connected to the cap beam 3. In this embodiment, the top section of the prefabricated column 21 is a solid structure. During construction, a cast-in-place concrete wet-jointed solid section 2112 is provided on the topmost column segment 211 by a cast-in-place method, and a pier top connecting steel bar 2113 is provided in the cast-in-place concrete wet-jointed solid section 2112 to connect to the cap beam 3, so as to improve the stability of the connection.

[0031] Preferably, the column segments 211 are provided with embedded steel plates, and the embedded steel plates are welded and connected between adjacent column segments 211. In this embodiment, the prefabricated components are all installed by tower cranes, and the column segments 211 are temporarily fixed by welding embedded steel plates. The temporary fixing measures meet the stress and stability requirements of the construction stage, and can realize the tensioning and anchoring of the prestressed coarse steel bars 215 after the continuous construction of several segments, thereby shortening the construction period.

[0032] Preferably, grouting holes are provided in the column segments 211; unitized assembled templates are provided between adjacent column segments 211, and the unitized assembled templates are connected to adjacent plate segments 221. The UHPC wet joint casting templates between the column segments 211 adopt unitized assembled templates, which are easy to install and disassemble. The templates are positioned and fastened using the installed prefabricated plate 22 segments. Grouting holes are provided in the prefabricated columns 21 to avoid grouting on the outside to affect the appearance of the pier column.

[0033] Please refer to Figures 14 to 31 A construction process of a lightweight assembled column-slab combined truss super-high pier structure includes the following steps: Step 1: Cast the base 1 and pre-embed the pier bottom thick steel bars 12, cast-in-place wet joint connecting steel bars 11 and temporarily connect the fixing steel plates; Step 2: Install the prestressed thick steel bar 215 and connect it to the pre-buried pier bottom thick steel bar 12 using the connector 217; Step 3: Install the first column segment 211 at the bottom of the prefabricated column 21, and use a jack to position and adjust; Step 4: Weld and connect the fixed steel plates, remove the adjustment jack, and install the snap-fit ​​sleeve 214 of the prestressed thick steel bar embedded pipe 213; Step 5: Install the first plate segment 221 of the prefabricated plate 22 and weld the angle steel 2233; Step 6: Install the wet joint formwork and pour the wet joint concrete; Step 7: Install the second column segment 211 of the prefabricated column 21 and use a jack to position and adjust it; Step 8: Weld and connect the fixed steel plates, remove the adjusting jack, and install the snap-fit ​​sleeve 214 of the prestressed thick steel bar embedded pipe 213; Step nine: installing the prefabricated truss 23 connecting the first column segment 211 and the second column segment 211 of the prefabricated column 21, and welding the connecting angle steel 2233; Step 10: Install the formwork, cast the column segment 211 joint, column-slab joint, and precast column 21 segment 1 column truss joint UHPC; Step 11: Install the second column segment 211 of the prefabricated panel 22 and weld the angle steel 2233; Step 12: According to Step 7 to Step 11, the third column segment 211 of the precast column 21 is installed, and the UHPC wet joint is cast, and the third plate segment 221 of the precast plate 22 is installed; Step 13: Install the prefabricated truss 23 between the second and third column segments 211 of the prefabricated column 21, and the UHPC of the column-truss joint of the second column segment 211 of the prefabricated column 21; Step 14: After the cast UHPC wet joint reaches the design strength, the prestressed coarse steel bars 215 are tensioned and anchored; Step 15: Install the extended thick steel bar 216; Step 16: Install the remaining pier body 2 segments according to Step 3 to Step 14 until the installation of the last segment and the anchoring of the extended thick steel bar 216 are completed; Step 17: Install the bottom formwork of the wet-jointed solid section of the pier top, install the steel bars, and pour the solid section concrete; Step 18: Casting cap beam 3.

[0034] This construction process adopts UHPC wet joint and steel-UHPC combined wet joint 223 technology: UHPC wet joints are used for joints between prefabricated pier column segments 211, and steel-UHPC combined wet joints 223 are used between column plate segments 221. UHPC material has 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 joints, and facilitate construction.

[0035] In addition, this construction process adopts partial prestressing technology and adopts reasonable prestressing force. Under the premise that the prestressed steel bars reach yield at the ultimate bearing capacity state, the tensile stress of the prestressed steel bars is reduced as much as possible, thereby achieving the goal of fully exerting the strength of the prestressed steel bar material and ensuring that the pier body 2 has good ductility and seismic resistance.

[0036] Finally, this construction process adopts the multi-segment continuous and rapid construction technology of pier columns. Temporary construction measures are used to meet the stress and stability requirements of the pier body 2 segments during the construction process. The segment construction does not need to wait for the joint materials 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 segments and the weight of the prefabricated components. The prefabricated column 21 is tilted inward to form a cross-sectional width along the bridge from large to small, thereby reducing the cross-bridge wind load; the truss structure is used to reduce the cross-bridge wind load; the prestressed steel bar bundle arrangement is used to increase the cross-sectional reinforcement ratio and improve the structural bearing capacity.

[0037] Beneficial effects of the present invention: The lightweight assembled column-slab combined truss super-high pier structure and its construction process provided by the present invention adopt UHPC wet joints, steel-UHPC combined wet joints and partially prestressed segment joint technology, and multi-segment continuous rapid construction technology, thereby realizing lightweight assembled construction of the pier body; the width of the cross-bridge section is changed from large to small by inclination of the prefabricated columns, thereby reducing the wind load in the transverse direction of the bridge; the wind load in the cross-bridge direction is reduced by adopting a truss structure; the cross-bridge wind load is increased by arranging the prestressed steel bar bundles, thereby increasing the cross-sectional reinforcement ratio and the structural bearing capacity. The structure is simple in structure, convenient in construction, good in durability, good in economy, energy-saving and environmentally friendly, and has broad prospects for promotion and application.

[0038] The above is a detailed introduction to the lightweight assembled column-slab combined truss super-high pier structure and its construction process provided by the present invention. For a general technician in this field, according to the ideas of the embodiments of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A lightweight assembled column-slab combined truss super-high pier structure, characterized in that: The invention comprises a base (1), a pier body (2) and a cap beam (3) which are connected in sequence from bottom to top; the pier body comprises a prefabricated column (21), a prefabricated plate (22) and a prefabricated truss (23); the cross section of the prefabricated column is a rectangular structure; two prefabricated columns on the front and rear sides along the bridge direction and two prefabricated plates form a box-shaped combined structure, and two adjacent box-shaped combined structures are connected to the prefabricated truss in the transverse direction of the bridge to form a truss structure.

2. The lightweight assembled column-slab combined truss super-high pier structure according to claim 1 is characterized in that: The two prefabricated columns on the front and rear sides along the bridge direction are symmetrically and inwardly arranged, and the length of the box-shaped combined structure along the bridge direction gradually changes along the height direction to form a structure that is wide at the bottom and narrow at the top.

3. The lightweight assembled column-slab combined truss super-high pier structure according to claim 2 is characterized in that: The prefabricated column is composed of a plurality of column segments (211), and adjacent column segments are connected by UHPC wet joints (212); a through prestressed coarse steel bar embedded pipe (213) is arranged in the column segment, and adjacent prestressed coarse steel bar embedded pipes are connected by snap-fit ​​sleeves (214); prestressed coarse steel bars (215) are arranged in the prefabricated column, and the prestressed coarse steel bars pass through the prestressed coarse steel bar embedded pipe; the ends of the prestressed coarse steel bars are connected to extended coarse steel bars (216), and the prestressed coarse steel bars and the extended coarse steel bars are connected by connectors (217).

4. The lightweight assembled column-slab combined truss super-high pier structure according to claim 1 is characterized in that: The prefabricated truss is a prestressed concrete structure. The end of the prefabricated truss is provided with a steel sleeve (231) and a truss connecting steel bar (232), and is connected to the prefabricated column through the steel sleeve and the truss connecting steel bar.

5. The lightweight assembled column-slab combined truss super-high pier structure according to claim 3 is characterized in that: The prefabricated plate is composed of a plurality of plate segments (221), and dry joints are used between adjacent plate segments, and shear keys (222) are arranged to be interlocked and connected with each other; a steel-UHPC combined wet joint (223) is used between the prefabricated column and the prefabricated plate, and between the prefabricated column and the prefabricated truss, and the steel-UHPC combined wet joint is composed of embedded channel steel (2231), embedded steel sleeve (2232), connecting angle steel (2233), embedded connecting steel bar (2234) and cast-in-place UHPC (2235).

6. The lightweight assembled column-slab combined truss super-high pier structure according to claim 1 is characterized in that: The pier body and the base are connected by a cast-in-place concrete wet joint, and cast-in-place wet joint connecting steel bars (11) and pier bottom thick steel bars (12) are arranged in the base.

7. The lightweight assembled column-slab combined truss super-high pier structure according to claim 3 is characterized in that: A cast-in-place concrete wet-jointed solid section (2112) is provided in the column segment located at the top, and a pier top connecting steel bar (2113) is pre-embedded in the cast-in-place concrete wet-jointed solid section; the prestressed coarse steel bars in the column segment located at the top and the pier top connecting steel bars extend into the cap beam and are connected to the cap beam.

8. The lightweight assembled column-slab combined truss super-high pier structure according to claim 3 is characterized in that: The column segments are provided with embedded steel plates, and adjacent column segments are connected by welding.

9. The lightweight assembled column-slab combined truss super-high pier structure according to claim 5 is characterized in that: Grouting holes are arranged in the column segments; unitized assembly templates are arranged between adjacent column segments, and the unitized assembly templates are connected to adjacent plate segments.

10. The construction process of the lightweight assembled column-slab combined truss super-high pier structure according to any one of claims 1 to 9, characterized in that: The following steps are included: Step 1: Cast the base and pre-embed the thick steel bars at the bottom of the pier, cast-in-place wet joint connecting steel bars and temporarily connect and fix the steel plates; Step 2: Install the prestressed thick steel bars and connect them with the embedded thick steel bars at the bottom of the pier using connectors; Step 3: Install the first column segment at the bottom of the prefabricated column and use a jack to position and adjust it; Step 4: Weld and connect the fixed steel plates, remove the adjustment jacks, and install the snap-on sleeves of the prestressed thick steel bar embedded pipes; Step 5: Install the first plate segment of the precast plate and weld the connecting angle steel; Step 6: Install the wet joint formwork and pour the wet joint concrete; Step 7: Install the second column segment of the prefabricated column and use a jack to position and adjust it; Step 8: Weld and connect the fixed steel plates, remove the adjustment jacks, and install the snap-on sleeves of the prestressed thick steel bar embedded pipes; Step 9: Install the prefabricated trusses connecting the first column segment and the second column segment of the prefabricated column, and weld the connecting angle steels; Step 10: Install the formwork, cast the column segment joints, column-slab joints, and precast column 1st segment column truss joints UHPC; Step 11: Install the second column segment of the precast panel and weld the connecting angle steel; Step 12: According to Step 7 to Step 11, install the third column segment of the precast column, cast the UHPC wet joint, and install the third slab segment of the precast slab; Step 13: Install the prefabricated truss between the second and third column segments of the prefabricated column, and the UHPC column-truss joint of the second column segment of the prefabricated column; Step 14: After the cast UHPC wet joint reaches the design strength, tension the prestressed coarse steel bars and anchor them; Step 15: Install the extended thick steel bars; Step 16: Install the remaining pier segments according to Steps 3 to 14 until the installation of the last segment and the anchoring of the extended thick steel bars are completed; Step 17: Install the bottom formwork of the wet-jointed solid section of the pier top, install the steel bars, and pour the solid section concrete; Step 18: Cast the cap beam.

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