CN111206492A - Transverse segmented prefabricated prestressed concrete bent cap structure and assembling method - Google Patents

Abstract

The invention discloses a transverse sectional precast assembling prestressed concrete bent cap structure and an assembling method, comprising a bent cap main body and precast upright columns; the cover beam main body comprises a plurality of prefabricated sections which are spliced along the transverse direction; a hole for penetrating a steel strand is reserved in each prefabricated segment; every two adjacent prefabricated segments are connected through a wet joint section; the joint surfaces of every two adjacent sections of the prefabricated sections, which are close to the two sides of the wet joint section, are respectively embedded with an upper section steel lapping structure and a lower section steel lapping structure which are matched; the transverse reinforcing steel bars of the top surface, the bottom surface and the vertical surface of each prefabricated section extend into the range of the corresponding wet joint section, and the transverse reinforcing steel bars of each prefabricated section and the transverse reinforcing steel bars of another adjacent prefabricated section are mutually staggered and overlapped. The invention realizes the small-tonnage sectional prefabrication and assembly of the large-volume prestressed concrete bent cap, can better ensure the stress of the bent cap structure, improves the structure quality and accelerates the construction speed.

Description

Transverse segmented prefabricated prestressed concrete bent cap structure and assembling method

Technical Field

The invention relates to the technical field of bridge prefabrication, assembly and construction, in particular to a transverse segmented prefabricated prestressed concrete bent cap structure and an assembling method.

Background

The prestressed concrete bent cap of the existing bridge structure is constructed by adopting a support cast-in-place method. However, with the development of society, the cast-in-place bent cap of the bracket gradually cannot meet the construction requirements of people on safety, civilization and environmental protection.

In recent years, integrally prefabricated capping beams, prefabricated lower layers, cast-in-place upper layer partially prefabricated capping beams and transversely segmented fully prefabricated assembly capping beams have been successively applied to bridges.

For a bridge with a wider bridge deck, the integrally prefabricated capping beam is heavier, the requirement on hoisting equipment is very high, and the economical efficiency is poor; when the tonnage of transportation and installation is limited, the lower layer is prefabricated, and the upper layer cast-in-place bent cap can not completely meet the requirements of actual engineering; the transverse segmented fully-prefabricated bent cap is not connected with reinforcing steel bars among the segments, the segments are connected into a whole completely by means of the prestressed steel strands, and the performance of resisting out-of-plane stress is slightly inferior to that of an integral cast-in-place bent cap.

Therefore, how to improve the performance of resisting out-of-plane stress at the joint surface of the precast prestressed concrete cover beam becomes a technical problem which needs to be solved urgently by the technical personnel in the field.

Disclosure of Invention

In view of the defects in the prior art, the invention provides a transverse sectional precast assembling prestressed concrete bent cap structure and an assembling method, and aims to realize the small-tonnage sectional precast assembling of a large-volume prestressed concrete bent cap, thereby facilitating the manufacture, transportation and installation of precast components, better ensuring the stress of the bent cap structure, improving the structure quality and accelerating the construction speed.

In order to achieve the purpose, the invention discloses a transverse subsection prefabrication and assembly prestressed concrete cover beam structure which comprises a cover beam main body and prefabricated stand columns used for supporting the cover beam main body.

The bent cap main body comprises a plurality of prefabricated sections which are spliced in the transverse direction; a hole for penetrating a steel strand is reserved in each prefabricated segment; every two adjacent prefabricated segments are connected through a wet joint section; the joint surfaces of every two adjacent sections of the prefabricated sections, which are close to the two sides of the wet joint section, are respectively embedded with an upper section steel lap joint structure and a lower section steel lap joint structure which are matched with each other;

and a plurality of transverse reinforcing steel bars of the top surface, the bottom surface and the vertical surface of each prefabricated section extend into the range of the corresponding wet joint section, and the plurality of transverse reinforcing steel bars of each prefabricated section and the plurality of transverse reinforcing steel bars of another adjacent prefabricated section are in staggered lap joint arrangement.

Preferably, the wet joint section is cast using UHPC concrete, a minimum of 300 mm.

Preferably, a plurality of transverse reinforcing steel bars of each prefabricated section and a plurality of transverse reinforcing steel bars of another adjacent prefabricated section are fixed in a binding mode, and the strength is ensured through the anchoring length in staggered overlapping.

The invention also provides an assembling method of the transverse segmented prefabricated prestressed concrete bent cap structure, which comprises the following steps:

step one, arranging a high-strength non-shrinkage mortar cushion layer and a supporting cushion block at the top end of the prefabricated stand column;

secondly, hoisting each prefabricated segment connected with the prefabricated upright post, and solidifying the prefabricated segment with the corresponding prefabricated upright post after grouting;

hoisting the prefabricated sections adjacent to the prefabricated sections consolidated with the prefabricated upright column one by one; in the hoisting process, the upper section steel overlapping structure and the lower section steel overlapping structure which are matched with each other between every two adjacent sections of prefabricated sections are accurately clamped together and accurately positioned; then, stretching a temporary prestressed tendon through a temporary fixing structure arranged on each prefabricated segment, and reliably and fixedly connecting each two adjacent prefabricated segments; each temporary prestressed tendon is anchored to the temporary fixing structure;

step four, unhooking the crane and binding steel bars; the formwork pours the wet joint sections between every two adjacent prefabricated sections;

step five, after the wet joint section reaches the design strength, the penetration and the tension of the steel strand are carried out in the holes of the corresponding prefabricated sections, and the corresponding temporary fixing structures, the corresponding temporary prestressed bundles and the corresponding anchoring structures are removed;

step six, repeating the step three to the step five until all the prefabricated sections are completely erected;

and seventhly, installing the upper structure, and sequentially tensioning the residual prestressed steel bundles to perform bridge deck pavement and construction of accessory facilities.

The invention has the beneficial effects that:

the application of the invention can realize the small-tonnage segmental prefabrication assembly of the large-volume prestressed concrete bent cap, thereby facilitating the manufacture, transportation and installation of prefabricated parts, better ensuring the stress of the bent cap structure (the crack stress steel bar is arranged in the splicing seam of the prefabricated segments, further improving the integral stress performance of the prestressed concrete prefabricated bent cap), improving the structure quality, accelerating the construction speed, improving the field civilized construction and reducing the influence on the environment.

The UHPC new material is used, so that the work of welding the reinforcing steel bars in the on-site wet joint can be avoided, the requirement on the anchoring length of the reinforcing steel bars is reduced, the size of the wet joint is reduced, the on-site construction workload is reduced, and the construction process is simplified.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

Fig. 1 shows a schematic structural diagram of a splicing state according to an embodiment of the present invention.

FIG. 2 shows a schematic view of the wet seam end construction as completed according to one embodiment of the present invention.

Fig. 3 shows a schematic structural view of the joint face of any two adjacent prefabricated segments according to an embodiment of the present invention.

Fig. 4 is a schematic structural diagram illustrating a completed assembly according to an embodiment of the present invention.

Detailed Description

Examples

As shown in fig. 1 to 4, the transverse segment precast assembly prestressed concrete capping beam structure includes a capping beam body 1 and precast columns 4 for supporting the capping beam body 1.

The bent cap main body 1 comprises a plurality of prefabricated sections 11 which are spliced in the transverse direction; a hole for penetrating a steel strand 15 is reserved in each prefabricated segment 11; every two adjacent prefabricated segments 11 are connected through a wet joint section 14; joint surfaces of two sides of each two adjacent prefabricated sections 11 close to the wet joint section 14 are respectively embedded with an upper section steel overlapping structure 12 and a lower section steel overlapping structure 13 which are matched;

the transverse reinforcing steel bars of the top surface, the bottom surface and the vertical surface of each prefabricated section 11 extend into the range of the corresponding wet joint section 14, and the transverse reinforcing steel bars of each prefabricated section 11 and the transverse reinforcing steel bars of another adjacent prefabricated section 11 are arranged in an overlapping mode in a staggered mode.

The principle of the invention is as follows: the steel sections are embedded in the wet joint sections 14 of the prefabricated cover beam sections 11 to realize the quick and accurate positioning of the post-erection prefabricated sections; the workload of the operation of the wet joint section 14 is reduced on site through a plurality of transverse steel bars extending out of the wet joint section 14 and the poured UHPC concrete, the construction speed is accelerated, the better stress performance of the prefabricated cover beam segment 11 in the surface and outside the surface of the wet joint section 14 is ensured, the small-tonnage prefabrication and the quick assembly of a large-volume prestressed concrete cover beam are realized, and the large-volume prestressed concrete cover beam has good stress performance.

In certain embodiments, the wet joint section 14 is cast in UHPC concrete, a minimum of 300 mm.

In some embodiments, the transverse reinforcing bars of each prefabricated section 11 are fixed with the transverse reinforcing bars of another adjacent prefabricated section 11 by binding, and the strength is ensured by the staggered and overlapped anchoring length.

The invention also provides an assembling method of the transverse segmented prefabricated prestressed concrete bent cap structure, which comprises the following steps:

step one, arranging a high-strength non-shrinkage mortar cushion layer and a supporting cushion block at the top end of a prefabricated upright post 4;

step two, hoisting each prefabricated segment 11 connected with the prefabricated upright post 4, and solidifying the prefabricated segment with the corresponding prefabricated upright post 4 after grouting;

step three, hoisting the prefabricated sections 11 adjacent to each prefabricated section 11 fixedly connected with the prefabricated upright post 4 one by one; in the hoisting process, the upper section steel overlapping structure 12 and the lower section steel overlapping structure 13 which are matched with each other between every two adjacent prefabricated sections 11 are accurately clamped together and accurately positioned; then, stretching the temporary prestressed tendons 2 through the temporary fixing structures 3 arranged on each prefabricated segment 11, and reliably and fixedly connecting each two adjacent prefabricated segments 11; each temporary prestressed tendon 2 is anchored to a temporary fixing structure 3;

step four, unhooking the crane and binding steel bars; the formwork pours a wet joint section 14 between each two adjacent prefabricated sections 11;

step five, after the wet joint section 14 reaches the design strength, the steel strand 15 is penetrated and tensioned in the hole of the corresponding prefabricated section 11, and the corresponding temporary fixing structure 3, the corresponding temporary prestressed beam 2 and the corresponding anchoring structure are removed;

step six, repeating the step three to the step five until all the prefabricated segments 11 are completely erected;

and seventhly, installing the upper structure, and sequentially tensioning the residual prestressed steel bundles to perform bridge deck pavement and construction of accessory facilities.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims (4)

1. The transverse subsection prefabrication and assembly prestressed concrete cover beam structure comprises a cover beam main body (1) and prefabricated stand columns (4) for supporting the cover beam main body (1); the method is characterized in that:

the cover beam main body (1) comprises a plurality of prefabricated sections (11) which are spliced along the transverse direction; holes for penetrating steel strands (15) are reserved in each prefabricated segment (11); every two adjacent prefabricated sections (11) are connected through a wet joint section (14); joint surfaces of two adjacent prefabricated sections (11) close to two sides of the wet joint section (14) are respectively embedded with an upper section steel overlapping structure (12) and a lower section steel overlapping structure (13) which are matched with each other;

the transverse reinforcing steel bars of the top surface, the bottom surface and the vertical surface of each prefabricated section (11) extend into the range of the corresponding wet joint section (14), and the transverse reinforcing steel bars of each prefabricated section (11) and the transverse reinforcing steel bars of another adjacent prefabricated section (11) are arranged in an overlapping mode in a staggered mode.

2. The transversely segmented prefabricated prestressed concrete cap beam construction according to claim 1, characterized in that said wet joint section (14) is cast with UHPC concrete, minimum 300 mm.

3. The structure of a transverse segmental prefabricated prestressed concrete cover beam according to claim 1, characterized in that a plurality of said transverse reinforcing bars of each of said prefabricated segments (11) are fixed with a plurality of said transverse reinforcing bars of another adjacent prefabricated segment (11) by means of binding, and the strength is ensured by the staggered overlapping anchoring length.

4. The assembling method of the transverse segmental prefabricating and assembling prestressed concrete cap beam structure according to claim 1, comprising the following steps:

step one, arranging a high-strength non-shrinkage mortar cushion layer and a supporting cushion block at the top end of the prefabricated upright post (4);

secondly, hoisting each prefabricated segment (11) connected with the prefabricated upright post (4), and solidifying the prefabricated segment with the corresponding prefabricated upright post (4) after grouting;

step three, hoisting the prefabricated sections (11) adjacent to the prefabricated sections (11) solidified with the prefabricated upright posts (4) one by one; in the hoisting process, the upper section steel overlapping structure (12) and the lower section steel overlapping structure (13) which are matched with each other between every two adjacent prefabricated sections (11) are accurately clamped together and accurately positioned; then, stretching a temporary prestressed tendon (2) through a temporary fixing structure (3) arranged on each prefabricated segment (11), and reliably and fixedly connecting each two adjacent prefabricated segments (11); each temporary pre-stressing tendon (2) is anchored to the temporary fixing structure (3);

step four, unhooking the crane and binding steel bars; erecting a formwork to cast the wet joint section (14) between each two adjacent prefabricated sections (11);

fifthly, after the wet joint section (14) reaches the designed strength, the steel strand (15) is penetrated and tensioned in the hole of the corresponding prefabricated section (11), and the corresponding temporary fixing structure (3), the corresponding temporary prestress bundle (2) and the corresponding anchoring structure are removed;

step six, repeating the step three to the step five until all the prefabricated segments (11) are completely erected;

and seventhly, installing the upper structure, and sequentially tensioning the residual prestressed steel bundles to perform bridge deck pavement and construction of accessory facilities.

Images