CN112796198A

CN112796198A - Hollow arch bridge system connected by UHPC wet joints and construction method

Info

Publication number: CN112796198A
Application number: CN202110156098.XA
Authority: CN
Inventors: 周敉; 吴雨航; 宋建伟; 马雷; 江坤; 高迈
Original assignee: Changan University
Current assignee: Changan University
Priority date: 2021-02-04
Filing date: 2021-02-04
Publication date: 2021-05-14

Abstract

A kind of empty belly type arch bridge system and construction method that adopts UHPC wet joint to connect, this system includes the concrete foundation set up on the foundation soil, abutment, prefabricated assembled rib arch set up on abutment, by the capping beam, prefabricated column and breast beam constituent belly hole pier, bridge road slab; the prefabricated assembling rib arch is prefabricated in three sections, and all prefabricated sections are connected through UHPC wet joints; constructing the main arch ring in a cable hoisting mode, and then constructing the arch building on the main arch ring; the UHPC wet joint is applied to the connection between the prefabricated arch ring segments, so that the superior performance of the UHPC is fully exerted, the overlapping length of the reserved steel bars at the joint can be effectively reduced, the bonding strength of each arch ring segment and the wet joint segment is enhanced, and each performance of the member under the normal working state and the extreme load action is ensured; and by adopting prefabricated construction, the construction efficiency can be greatly improved, and the construction period is shortened.

Description

Hollow arch bridge system connected by UHPC wet joints and construction method

Technical Field

The invention relates to the technical field of arch bridges, in particular to a hollow arch bridge system connected by UHPC wet joints and a construction method.

Background

The arch bridge is one of the main structural forms of highway bridges in China, wherein the reinforced concrete arch bridge fully utilizes the stress advantages of concrete and steel, effectively improves the economic performance of the arch bridge, enlarges the application range of the arch bridge, is widely applied to valley-crossing bridges in mountainous areas in China, however, as the main arch ring can not be stressed before being folded, most of the construction of the main arch ring is carried out by adopting a method of erecting a support for casting or building in situ, the construction process is more complicated, the processes of foundation treatment, support erection, support pre-pressing and the like are often needed, the foundation treatment is more troublesome in areas with poor geological conditions, accidents are easy to occur when the foundation is dropped, the support can not be erected when the areas such as gorges, rivers and the like need to be spanned, the application range of the reinforced concrete arch bridge is limited, compared with the bridge construction, the mechanization degree is low, the dust and noise pollution is serious, the assembly construction development progress is laggard, the technical innovation of the construction mode is slow, and the development of bridge industrialization and assembly is not facilitated.

With the continuous and rapid development of national economy, the improvement of energy-saving and environment-friendly requirements in engineering construction and the continuous increase of labor cost, the research and application of China in the aspect of concrete assembly construction technology gradually increase in temperature, and the promotion of bridge assembly construction is in the trend. The bridge assembly construction can save resources for the building industry, reduce pollution, improve the operation conditions of workers and reduce the labor intensity of the workers, meets the requirements of novel industrialization, informatization and greening, and is the inherent requirement of economic development in China. Therefore, it becomes an important task for engineering technicians to find a prefabricated assembled arch bridge structure with rapid construction, strong bearing capacity and wide application range.

Disclosure of Invention

In order to respond to the transformation and upgrade of the bridge engineering construction industry from the traditional industry to the industrialized production, the assembled construction and the green construction, and solve the problems of complex construction process and long construction period of the arch bridge, the invention aims to provide the hollow arch bridge system and the construction method which adopt the UHPC wet joint connection.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a hollow arch bridge system adopting UHPC wet joint connection comprises a concrete foundation 1 arranged on a foundation soil layer, arch bases 2 and abutment platforms 3 arranged on the foundation 1, arch rings 4 prefabricated and assembled by reinforced concrete are arranged on the two arch bases 2, and a belly hole pier 6 and a bridge plate 7 are arranged on the arch bases 2;

the arch ring 4 is divided into 3 sections, the two side sections 10 and the middle section 11 are spliced through a UHPC wet joint 5, each side section 10 and the middle section 11 are composed of two arch ribs 8 and a transverse tie beam 9, and the cross sections of the arch ribs 8 are rectangular.

The UHPC wet joint 5 is formed by pouring ultra-high performance concrete, the connection structure of two sides of the wet joint 5 is a diamond shape, the main reinforcement of the side section 10 and the middle section 11 extends out and is welded on a single side, the compressive strength of the UHPC material is not less than 130Mpa, the content of steel fiber is not less than 0.02 percent, and in order to ensure the bearing capacity and durability requirements of the wet joint, the length L of the UHPC wet joint 5 is calculated and determined according to the following formula:

in the formula:

l is UHPC wet seam length (mm);

f is the ultimate tensile strength (Mpa) of the longitudinal steel bar;

c is the thickness (mm) of the concrete protective layer;

d is the diameter (mm) of the steel bar;

when the wet seam length calculated according to the above formula is less than 10d, 10d is taken as the UHPC wet seam length.

The abutment 3 and the arch support 2 are formed by pouring common reinforced concrete materials, the embedded steel bars 12 of the arch support 2 extend out of the joint of the side sections 10 and are welded, and after the arch ring 4 is folded, the embedded steel bars are welded with the side sections 10 on the two sides and are poured with common concrete for connection.

The abdominal hole pier 6 is formed by pouring common reinforced concrete materials and is connected with the arch ring 4 through a bottom beam 14, a bottom beam grinding core 16 is arranged at the lower end of the abdominal hole pier 6, longitudinal reinforcing steel bars extend out of the periphery of the bottom beam grinding core, and concrete is poured after the longitudinal reinforcing steel bars and the extending reinforcing steel bars of the bottom beam 14 are welded; the upper end of the abdominal hole pier 6 is prefabricated with a notch 19, and the vertical steel bars of the upright post in the notch 19 are welded with the extending steel bars on the bottom surface of the bent cap 17 and then sealed by high-strength mortar.

Based on the construction method of the hollow prefabricated assembled arch bridge system adopting the ultra-high performance concrete (UHPC) wet joint connection, the construction method comprises the following steps:

the method comprises the following steps: excavating a foundation pit, constructing a concrete foundation 1, and pouring an arch support 2 and an abutment 3; synchronously prefabricating an arch rib 8;

step two: moving the prefabricated arch rib 8 to a site through transportation equipment, lifting the side section 10 to an installation position, temporarily fixing the arch rib 8 by using a buckle lock, lifting the middle section 11, adjusting the arch axis and the elevation, chiseling 5-10 mm of surface concrete at a joint, cleaning, keeping the surface wet, welding a wet joint main rib, welding a single-side welding length not less than 10d, wherein d is the diameter (mm) of a steel bar, erecting a mold and pouring a UHPC wet joint 5, pouring a transverse beam 9 after the closure is finished, welding a steel bar 12 reserved in the arch support 2 and an arch ring 4 main rib, and pouring arch foot concrete 13 to finish the sealing and reaming;

step three: welding 14 steel bars of the bottom beam and prefabricated upright column steel bars, and pouring concrete at the bottom of the column; the steel bars of the upright columns in the welding notch 19 and the steel bars extending out of the bottom surface of the bent cap 17 are sealed by high-strength mortar, and the welding length of the steel bars needs to meet the standard requirement;

step four: and hoisting the bridge deck plates 7 to finish the construction of the bridge deck system and additionally arranging the railings.

The UHPC material is applied to the joint structure of the hollow arch bridge, the advantages of high compressive strength and compressive strength, super toughness, good durability, small shrinkage and the like of the UHPC are fully utilized, the problems that the joint between the sections of the traditional arch bridge is easy to crack and damage and the like due to low bonding strength of the cast-in-place concrete and the original concrete section are solved, and the interface connection strength and the section impermeability are effectively ensured; and the UHPC material can reach enough strength in a short curing time, and by combining a construction method of prefabrication and assembly, the construction efficiency can be greatly improved, the construction period can be shortened, and great economic benefits can be obtained. Therefore, the invention has great practical value and good economic benefit, and especially has wide application prospect in the technical field of arch bridge construction.

Drawings

Fig. 1 is a schematic structural view of a hollow arch bridge system using UHPC wet joint connection according to the present invention.

Fig. 2 is a schematic view of each prefabricated segment of the main arch ring of the invention.

Fig. 3 is a schematic cross-sectional view of a rib of the present invention employing a pre-fabricated arch ring segment.

Fig. 4 is a schematic view of a wet seam construction of a prefabricated arch ring segment in accordance with the present invention.

Fig. 5 is a schematic view of the arch leg joint configuration of the present invention.

FIG. 6a is a schematic view of the construction of the prefabricated pillar to sill joint of the present invention.

Figure 6b is a cross-sectional view of the prefabricated pillar to sill joint of the present invention.

Fig. 7 is a schematic view of the construction of the prefabricated upright and bent cap joint of the present invention.

Fig. 8 a-8 f are schematic diagrams of the construction process of the hollow prefabricated assembled arch bridge system connected by UHPC wet joints.

Wherein: 1. a concrete foundation; 2. an arch support; 3. an abutment; 4. an arch ring; 5. UHPC wet seaming; 6. a ventral pore pier; 7. a bridge plate; 8. an arch rib; 9. a transverse tie beam; 10. a side section; 11. a middle section; 12. reinforcing steel bars; 13. arch foot concrete; 14. a bottom beam; 15. wet seaming of the bottom beam and the web hole pier; 16. grinding the core by the bottom beam; 17. a capping beam; 18. the bottom surface of the bent cap extends out of the steel bar; 19. a notch.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

As shown in figure 1, the open-web arch bridge system adopting UHPC wet joint connection comprises a concrete foundation 1 arranged on a foundation soil layer, an arch base 2 and an abutment 3 which are arranged on the foundation 1, arch rings 4 which are prefabricated and assembled by reinforced concrete are arranged on the two arch bases 2, and an abdominal hole pier 6 and a bridge plate 7 are arranged on the arch base 2.

As shown in fig. 2 and 3, the arch ring 4 is divided into 3 sections, and is formed by splicing side sections 10 and a middle section 11 at two sides through a UHPC wet joint 5, wherein each of the side sections 10 and the middle section 11 is composed of two arch ribs 8 and a transverse tie beam 9, and the cross section of each arch rib 8 is rectangular.

As shown in fig. 4, the UHPC wet joint 5 is formed by pouring ultra-high performance concrete, the connection structure of the two sides of the wet joint 5 is a diamond shape, the main reinforcement of the side section 10 and the main reinforcement of the middle section 11 extend out and are welded on the single side, the compressive strength of the UHPC material is not less than 130Mpa, the content of steel fiber is not less than 0.02%, and in order to ensure the bearing capacity and durability requirements of the wet joint, the length L of the UHPC wet joint 5 can be determined by the following formula:

in the formula:

l is UHPC wet seam length (mm);

f is the ultimate tensile strength (Mpa) of the longitudinal steel bar;

c is the thickness (mm) of the concrete protective layer;

d is the diameter (mm) of the steel bar;

As shown in fig. 5, the abutment 3 and the arch support 2 are formed by pouring common reinforced concrete materials, the embedded steel bars 12 of the arch support 2 extend out of the joint with the side sections 10 and are welded, and after the arch ring 4 is closed, the embedded steel bars are welded with the side sections 10 at two sides and are poured with common concrete for connection.

As shown in fig. 6a, 6b and 7, the web-hole piers 6 are formed by pouring common reinforced concrete materials and are connected with the arch ring 4 through bottom beams 14, bottom beam grinding cores 16 are arranged at the lower ends of the web-hole piers 6, longitudinal steel bars extend out from the peripheries of the bottom beam grinding cores, and concrete is poured after the longitudinal steel bars are welded with the steel bars extending out of the bottom beams 14; the upper end of the abdominal hole pier 6 is prefabricated with a notch 19, and the vertical steel bars of the upright post in the notch 19 are welded with the extending steel bars on the bottom surface of the bent cap 17 and then sealed by high-strength mortar.

Referring to fig. 8a to 8f, the construction method of the hollow prefabricated assembled arch bridge system connected by Ultra High Performance Concrete (UHPC) wet joints based on the above method comprises the following steps:

the method comprises the following steps: clearing obstacles around the bridge site to be built and vacating a working surface for construction; excavating a foundation pit, constructing a foundation 1, and pouring an arch support 2 and an abutment 3; trial pulling of the ground anchor, opposite pulling of the buckle lock and trial hoisting of the main cable system; and synchronously prefabricating the arch rib 8.

Step two: moving the prefabricated arch rib 8 to a field through transportation equipment, lifting the side section 10 to an installation position, temporarily fixing the arch rib 8 by using a buckle lock, lifting the middle section 11, adjusting the arch axis and the elevation, chiseling 5-10 mm of surface concrete at a joint, cleaning, keeping the surface wet, welding a main wet joint rib, supporting a mold, pouring a UHPC wet joint 5, and pouring a transverse beam 9 after closing; and welding the steel bars 12 reserved in the arch support 2 and the main bars of the arch ring 4, and pouring arch springing concrete 13 to finish sealing and reaming.

Step three: welding 14 steel bars of the bottom beam and 6 steel bars of the web hole pier, and pouring concrete at a wet joint 15 of the bottom beam and the web hole pier; and (3) welding reinforcing steel bars in the notch 19 and extending out of the reinforcing steel bars 18 on the bottom surface of the cover beam 17, and sealing the notch 19 by using high-strength mortar.

Claims

1. The utility model provides an adopt empty stomach formula arched bridge system of UHPC wet joint connection, is including setting up concrete foundation (1) on the foundation soil layer, hunch seat (2) and abutment (3) that set up on foundation (1), and prefabricated arch ring (4) of assembling of reinforced concrete sets up on two hunch seats (2), is provided with binder pier (6) and bridge way board (7) on hunch seat (2), its characterized in that, hunch ring (4) divide into 3 sections, by the border section (10) of both sides with interlude (11) through UHPC wet joint (5) concatenation form, border section (10) and interlude (11) are constituteed by two arch ribs (8) and a horizontal tie beam (9), wherein arch rib (8) cross-section is the rectangle.

2. The open arch bridge system connected by the UHPC wet joint according to claim 1, characterized in that the UHPC wet joint (5) is formed by pouring ultra-high performance concrete, the connection structure of the two sides of the wet joint (5) is diamond, the main bars of the side section (10) and the middle section (11) are extended and welded on one side, the compressive strength of the UHPC material is not less than 130Mpa, the steel fiber content is not less than 0.02%, and the length L of the UHPC wet joint (5) is determined by the following formula to ensure the bearing capacity and durability requirements of the wet joint:

in the formula:

l is UHPC wet seam length (mm);

f is the ultimate tensile strength (Mpa) of the longitudinal steel bar;

c is the thickness (mm) of the concrete protective layer;

d is the diameter (mm) of the steel bar;

3. The open-web arch bridge system connected by UHPC wet joints according to claim 1, characterized in that the abutment (3) and the arch support (2) are constructed by casting ordinary reinforced concrete materials, the embedded steel bars (12) of the arch support (2) are extended and welded at the joint with the side sections (10), and after the arch ring (4) is closed, the embedded steel bars are welded with the side sections (10) at both sides and cast ordinary concrete for connection.

4. A hollow arch bridge system adopting UHPC wet joint connection is characterized in that a belly hole pier (6) is formed by pouring common reinforced concrete materials and is connected with an arch ring (4) through a bottom beam (14), a bottom beam grinding core (16) is arranged at the lower end of the belly hole pier (6), longitudinal steel bars extend out from the periphery of the bottom beam grinding core, and concrete is poured after the longitudinal steel bars are welded with the extending steel bars of the bottom beam (14); the upper end of the abdominal hole pier (6) is prefabricated with a notch (19), and the vertical steel bar of the upright post in the notch (19) is welded with the extending steel bar on the bottom surface of the capping beam (17) and then sealed by high-strength mortar.

5. A hollow arch bridge system connected by UHPC wet joints and a construction method thereof are characterized by comprising the following steps:

the method comprises the following steps: excavating a foundation pit, constructing a concrete foundation (1), and pouring an arch support (2) and a bridge abutment (3); synchronously prefabricating arch ribs (8);

step two: moving the prefabricated arch rib (8) to a site through transportation equipment, lifting the side section (10) to an installation position, temporarily fixing the arch rib (8) by using a buckle lock, lifting the middle section (11), adjusting the arch axis and the elevation, chiseling 5-10 mm of surface concrete at a joint, cleaning, keeping the surface wet, welding a wet joint main rib, welding a single-side welding length not less than 10d, wherein d is the diameter (mm) of a steel bar, erecting a mold, pouring a UHPC (ultra high performance concrete) wet joint (5), pouring a transverse tie beam (9) after the folding is finished, welding a steel bar (12) reserved by an arch support (2) and an arch ring (4) main rib, pouring arch foot concrete (13), and finishing the sealing and reaming;

step three: welding reinforcing steel bars of the bottom beam (14) and prefabricated upright column reinforcing steel bars, and pouring concrete at the bottom of the column; the steel bars of the stand columns in the welding notches (19) and the steel bars extending out of the bottom surfaces of the bent caps (17), high-strength mortar is used for sealing the notches (19), and the welding length of the steel bars needs to meet the standard requirement;

step four: hoisting the bridge deck slab (7), completing the construction of the bridge deck system and additionally arranging the railings.