Based on the construction method for mixing prestressed assembled corrugated steel web plate composite box girder
Technical field
The present invention relates to bridge construction technology fields, are answered in advance based on mixing suitable for large bridge more particularly, to a kind of
The construction method of the assembled corrugated steel web plate composite box girder of power.
Background technology
Traditional prefabricated case beam web is mostly concrete material, and not only weight is big and easy to crack, therefore concrete box girder is only suitable for
Applied to small across footpath(40m or less)Highway bridge.PC box girder with corrugated steel webs is using the efficient corrugated sheet steel conduct of shearing resistance
Web not only mitigates the dead weight of box beam, but also since Wavelike steel webplate is distinctive " fold effect ", prestressing force can efficiently apply
On concrete roof and floor, in recent years in large and medium-sized bridge(50m or more across footpaths)It is upper to be widely applied.
Existing Wavelike steel webplate PC combined box beams mostly use the following two kinds form and construct:
One is by the reinforcing bar precast concrete top plate, reinforcing bar precast concrete bottom plate and waveform steel abdomen of entire box girder body
Plate is divided into three parts and carries out respectively integral prefabricated, lifts again later in place, assembly is connected by screw bolts at bridge location.It is Chinese special
Sharp " pin-connected panel prestressed concrete combined box beam "(Application number 200620126505.3)The prefabricated component of above structure is disclosed,
And the connection type of Wavelike steel webplate and top plate and bottom plate is highlighted.But due to the box beam top plate and bottom plate of this structure
It is an integral structure with web, the weight of single prefabricated components is still very heavy.Such as the Wavelike steel webplate that bridge width is 16.75m
Box girder bridge, the weight per linear meter(lin.m.) is up to 10t or more, even if it is still very difficult to lift single prefabricated components when construction respectively.
Secondly, for convenience of transporting, the length of prefabricated components usually will not be very long, and above-mentioned full span erection structure is only limitted to the bridge of small across footpath
Beam, for the bridge of Long span, top plate and web still can use and be segmented prefabricated form.In addition, the patent does not account for reality
Application opportunity of prestressed strand and situations such as reserving hole channel when border is constructed, and also not plus opinion for the treatment measures of hogging moment area
State, if lacking the detailed consideration of the measure and Specific construction process aspect of reply beam body loaded deformation, the feasibility of construction compared with
Difference.
Another kind is that top plate and bottom plate and Wavelike steel webplate are fixed to the precast assembly unit for being linked to be I-shaped structure, at the scene
For example " two times tensioning is pre- for Chinese patent for completion bridge construction after the assembled rigid unit of multiple I-shaped structures is carried out horizontal and vertical splicing
Stress assembled Wavelike steel webplate combination beam and its construction method "(Application number 201510255113.0)Disclose above structure
Transverse H-shaped prefabricated member, and apply secondary prestress in corresponding opportunity, realize the laterally assembled of transverse H-shaped prefabricated member.It is above-mentioned pre-
The assembled rigid unit volume of system is big, tonnage weight(Such as weight of the single prefabricated I-shaped unit per linear meter(lin.m.) is i.e. up to 5t or so), and
And the stability of itself is also poor, easily causes transportation cost and hoisting cost rises;During the installation process to lifting appliance requirement
Higher, hoisting safety is relatively low.
Invention content
The present invention provides a kind of based on the construction method for mixing prestressed assembled corrugated steel web plate composite box girder, purpose
It is to be susceptible to transport, lifting and later maintenance when solving existing Wavelike steel webplate PC combined box beams applied to large bridge
Etc. the problem of.
To achieve the above object, the present invention makes full use of the characteristics of corrugated steel web plate composite box girder, in different plates in
Different opportunitys apply prestressing force:For Wavelike steel webplate combination beam, since Wavelike steel webplate has the spy of non resistance axle power
Point, the axial force of precast concrete bottom plate can reach natural separation over time and space with outer Prestressing, thus
It can be by the prestressing force single tension of precast concrete bottom plate to design value;Utilize the spy of corrugated sheet steel combination beam " weak beam-ends effect "
Point, precast concrete bottom plate is interior to use linear type pretensioned prestressing steel beam.After the completion of completing lateral I-beam assembly, then open
The top plate prestressed strand for drawing the secondary prestress steel beam and adjacent across footpath pier top hogging moment area of precast concrete bottom plate, specifically may be used
Take following technical proposals:
Construction method of the present invention based on the prestressed assembled corrugated steel web plate composite box girder of mixing, it is main to wrap
Include following steps:
The first step, by Bridge Design requirement, the independent precast concrete top plate of prefabricated composition i-shaped beams body unit, prefabricated
Concrete floor and Wavelike steel webplate:
For precast concrete top plate, first binding is provided with the top plate of lateral connection muscle, longitudinally connected muscle and peg notch
Bar-mat reinforcement, the peg notch is longitudinally spaced to be arranged in roof steel bar net both sides, then pier top hogging moment prestressed pore passage is pacified
In roof steel bar net, poured later;
For precast concrete bottom plate, tensioning equipment is first passed through to pretensioned prestressing steel Shu Jinhang tensioning, then bind and set
It is equipped with the baseplate reinforcing bar net of lateral connection muscle, longitudinally connected muscle and peg notch, the longitudinally spaced setting of peg notch exists
Baseplate reinforcing bar net both sides, and baseboard prestress duct is mounted in baseplate reinforcing bar net, installation form later, casting concrete,
After concrete reaches design strength, form removal loosens pretensioned prestressing steel beam;
For Wavelike steel webplate, first punch process corrugated sheet steel, then flange plate is welded at corrugated sheet steel both ends, later in institute
It states and welds multigroup spaced peg group on flange plate;
Second step carries out assembled in situ preparation:
Setting Mobile support device is as auxiliary construction platform between completing the adjacent abutment or bridge pier of construction at the scene, together
When, by the precast concrete top plate, precast concrete bottom plate and corrugated steel web transport of prefabricated completion to construction site;
Third walks, and carries out i-shaped beams body unit and its horizontally-spliced assembly:
Precast concrete bottom plate is lifted to Mobile support device using hanging device, Wavelike steel webplate is hung in recurrence, and
Wavelike steel webplate bottom peg group is inserted into the peg notch of precast concrete bottom plate;Later, lifting precast concrete top
Plate completes first I-shaped equally by peg group inserting to the peg notch of precast concrete top plate at the top of Wavelike steel webplate
The assembly of type beam body unit is constructed;
Then Mobile support device is walked along bridge wide direction horizontal transfer according to the construction of first i-shaped beams body unit
Suddenly the assembly construction for other i-shaped beams body units being transversely arranged in the spanning is completed;Adjacent I-shaped beam body is bound later
Lateral connection muscle between unit top plate and bottom plate, pours to form precast concrete top plate longitudinal wet joint and precast concrete bottom
Plate longitudinal wet joint, later to the secondary prestress steel Shu Jinhang tensioning in baseboard prestress duct;
4th step is combined the longitudinal spliced assembly of beam:
Mobile support device is transferred to other spanning positions successively, third is repeated and walks operation, completes longitudinal each spanning
The construction of beam body;
Longitudinally connected muscle of the adjacent bridge between top plate and bottom plate is bound, pours to form laterally wet seam or crossbeam, and according to
The sequence of central sill after first side bar, using symmetrical tensioning principle to being located at contiguous prefabricated concrete roof pier top hogging moment prestress hole
Tensioning steel Shu Jinhang tensioning in road forms continuous beam on many supports system;
5th step completes the erection of affiliated facility, terminates construction.
Form single precast concrete top plate, precast concrete bottom plate and the Wavelike steel webplate of the i-shaped beams body unit
Length be respectively 5-30 meters.
Construction method of the present invention based on the prestressed assembled corrugated steel web plate composite box girder of mixing, using list
Precast concrete top plate, precast concrete bottom plate and the Wavelike steel webplate of only prefabricated i-shaped beams body unit reproduce field and are spelled
Connect the mode of construction.The present invention carries out piecemeal to existing integral prefabricated I-shaped component in a vertical enterprising step, on the one hand
" the fold effect " for taking full advantage of Wavelike steel webplate realizes that box beam breaks the whole up into parts, and prefabricated components volume is fully reduced, structure is made
Part volume reduces, and is easy to transport and lift, is conducive to the fast erecting of bridge, while avoiding integral prefabricated I-shaped component
The problem of self stability difference;On the other hand also utilize Wavelike steel webplate distinctive weak " beam-ends effect ", on precast concrete top
It is provided with the prestressed pore passage for wearing pier top hogging moment tensioning steel beam in plate, is provided in precast concrete bottom plate and first opens
Method prestressed strand and secondary prestress steel beam realize that the maximum of construction is convenient with work progress perfect cooperation.Wherein, into
The tensioning of pretensioning steel beam is carried out before row precast concrete bottom plate, and it is complete completing lateral I-beam body unit assembly
Cheng Hou, then tensioning secondary prestress steel beam, the stress for resisting concrete shrinkage and creep generation;Web passes through end peg group
Be inserted into top, the mode in bottom plate peg notch is attached, be connected firmly, construct it is convenient.Adjacent top plate and bottom plate is in bridge
Beam construction site can by pour wet seam arrangements carry out splicing laterally and/or longitudinally it is wide with the bridge for obtaining various requirement,
Spanning.Specifically, advantages of the present invention can be embodied in the following:
(1)The present invention carries out beam body erection using the structure type of precast block assembly, and the volume and weight of each component are all
It is corresponding smaller, stability of the prefabricated component in transportational process can not only be effectively ensured, and be easily guaranteed that component in hoisting process
Safety, be conducive to construction.
(2)The achievable scale of various prefabricated components is prefabricated in the present invention, effectively increases construction efficiency, shortens construction
Period.
(3)The present invention applies different types of prestressing force on different opportunitys to top plate and bottom plate, and all using pre- in vivo
Stress rib, prestress application effect are relatively stable;Due to the deformed bar negligible amounts of tensioning at the scene, construction party
Just, fast.
Description of the drawings
Fig. 1 is the structural schematic diagram of i-shaped beams body unit in the present invention.
Fig. 2 is the structural schematic diagram of precast concrete top plate in Fig. 1.(Omit longitudinally connected reinforcing bar)
Fig. 3 is the structural schematic diagram of precast concrete bottom plate in Fig. 1.(Omit longitudinally connected reinforcing bar)
The structural schematic diagram of Wavelike steel webplate in Fig. 4 Fig. 1.
Fig. 5, Fig. 6, Fig. 7 are work progress schematic diagrames.
Fig. 8-13 is the relevant drawings that schematic illustration is carried out to the present invention.
Specific implementation mode
Construction method of the present invention based on the prestressed assembled corrugated steel web plate composite box girder of mixing, it is main to wrap
Include following steps:
The first step, by Bridge Design requirement, independent prefabricated composition i-shaped beams body unit(As shown in Figure 1)Concrete
Native top plate 1, precast concrete bottom plate 2 and Wavelike steel webplate 3:
Specifically, when prefabricated precast concrete top plate 1 as shown in Figure 2, first binding is provided with lateral connection muscle 1.1, vertical
To the roof steel bar net of dowel and peg notch 1.2, the peg notch 1.2 is longitudinally spaced to be arranged in roof steel bar net two
Side, then pier top hogging moment prestressed pore passage 1.3 is mounted in roof steel bar net, it is poured later;
When prefabricated precast concrete bottom plate 2 as shown in Figure 3, first the precalculated position on pre-tensioning system stretching bed is fixed and is first opened
Method prestressed strand 2.2 is stretched to design value, then binds and be provided with lateral connection muscle 2.1, longitudinally connected muscle and peg notch 2.3
Baseplate reinforcing bar net, the peg notch 2.3 is longitudinally spaced to be arranged in baseplate reinforcing bar net both sides, and by baseboard prestress duct
2.4 are mounted in baseplate reinforcing bar net, later installation form, casting concrete, after concrete reaches design strength, remove mould
Plate loosens pretensioned prestressing steel beam 2.2, completes the prefabricated of mixing prestressing force precast concrete bottom plate 2, above-mentioned pre-tensioning system is answered in advance
Power steel beam 2.2 is used to resist the stress of concrete shrinkage and creep generation;
When prefabricated Wavelike steel webplate 3 as shown in Figure 4, first punch process corrugated sheet steel, then welded at corrugated sheet steel both ends
Flange plate 3.1 welds multigroup spaced peg group 3.2 on the flange plate 3.1 later;Above-mentioned peg group 3.2 with top,
Peg notch 1.2,2.3 positions on bottom plate is corresponding, and shape matches, and can securely insert.
Second step carries out assembled in situ preparation:
Setting Mobile support device is as auxiliary construction platform between completing the adjacent abutment or bridge pier of construction at the scene, together
When, the precast concrete top plate 1, precast concrete bottom plate 2 and Wavelike steel webplate 3 of prefabricated completion are transported to construction site.
Third walks, and carries out i-shaped beams body unit and its horizontally-spliced assembly:
Precast concrete bottom plate 2 is lifted to Mobile support device 4 using hanging device(As shown in Figure 5)On, then lift by crane
Wavelike steel webplate 3, and 3 bottom peg group of Wavelike steel webplate is inserted into the peg notch of precast concrete bottom plate 2;Later,
Precast concrete top plate 1 is lifted by crane, 3 top peg group of Wavelike steel webplate is equally inserted to the peg slot to precast concrete top plate 1
In mouthful, the assembly construction of first i-shaped beams body unit is completed.
Then by Mobile support device 4 along bridge wide direction horizontal transfer, according to the construction of first i-shaped beams body unit
Step completes the assembly construction for other i-shaped beams body units being transversely arranged in the spanning;Adjacent i-shaped beams are bound later
Lateral connection muscle 1.1,2.1 between body unit top, bottom plate, and pour and to form precast concrete top plate longitudinal wet joint 5 and pre-
Concrete floor longitudinal wet joint 6 processed(As shown in Figure 6).In order to resist the moment of flexure of second phase load generation, when above-mentioned longitudinal wet connects
After seam reaches some strength, design value need to be stretched to the secondary prestress steel Shu Jinhang in baseboard prestress duct 2.4.
The i-shaped beams body unit of above-mentioned lateral connection constitutes single chamber structure as shown in FIG. 6, also can continuously splice
Group chamber in pairs or more chamber structures.
4th step is combined the longitudinal spliced assembly of beam:
Mobile support device 4 is transferred to other spanning positions successively, third is repeated and walks operation, completes longitudinal each spanning
The construction of beam body;
Longitudinally connected muscle of the adjacent bridge between top, bottom plate is bound, pours to form laterally wet seam or crossbeam 7(Such as Fig. 7 institutes
Show);In order to resist the pier top hogging moment of adjacent across footpath box beam, when laterally wet seam or crossbeam 7 reach some strength, according to elder generation
The sequence of central sill after side bar, using symmetrical tensioning principle to being located at contiguous prefabricated concrete roof pier top hogging moment prestressed pore passage
Tensioning steel Shu Jinhang tensioning in 1.3 forms continuous beam on many supports system;
5th step completes the erection of affiliated facility, terminates construction.
In order to reduce the workload of the wet seam of cast in situs, construction efficiency is improved, the single of i-shaped beams body unit is formed
The length of precast concrete top plate 1, precast concrete bottom plate 2 and Wavelike steel webplate 3 is respectively 5-30 meters.
It is vertically to be spliced to Wavelike steel webplate built H beam of the present invention below, applies mixing this construction of prestressing force
The concrete principle explanation that feasibility, the reasonability of method are made:
Stress of the analysis precast concrete bottom plate under two states first.
1. the 1st state:
Precast concrete bottom plate as shown in Figure 8, the prestressing force that the stretch-draw prestressing force steel beam being arranged inside is applied are N,
Then the section upper stress on precast concrete bottom plate is:
2. the 2nd state:
When above-mentioned precast concrete floor combination becomes I-shaped Wavelike steel webplate combination beam, I-shape cross section structure
As shown in Figure 9.
Apply prestressing force N on precast concrete bottom plate, the moment of flexure to compound section neutral axis is:
It is obtained by the area moment of upper lower section is equal:
The area of combination beam total cross-section is:
The moment of inertia of whole cross section is:
Wavelike steel webplate combination beam can not consider web when anti-bending bearing capacity calculates due to the non resistance axle power of web
Effect is equivalent to no web plate section, therefore sets:
Then:
The stress of top plate:
Enable ratio of height to thickness
The then stress of top plate:
The stress of bottom plate:
Have for general combination beam section, can obtain
By taking the Wavelike steel webplate combination beam of 30m across footpaths as an example.If, at this time, bring formula into(9)With(10):
When the across footpath of bridge further increases,WithIt further increases, formula(10)Meet
It can be seen that under the 1st state and the 2nd state, the stress approximately equal of precast concrete bottom plate.That is, first
The prestressing force that phase applies in the prefabricated panel stage is still held essentially constant after being overlapped into Wavelike steel webplate combination beam.Therefore claim
Wavelike steel webplate combination beam take it is vertical layered it is assembled before and after this mechanical characteristics that can be held essentially constant of stress be overlapping by
Power invariance.This characteristic is that the vertical layered splicing of Wavelike steel webplate combination beam provides the foundation.
On the basis of above-mentioned analysis, it is back to discuss ordinary steel-and mixes built H beam and Wavelike steel webplate built H beam
It is vertical split with it is assembled during stress variation.Wherein, using prestressing force as only consideration external force:
1. vertical split process:
Figure 10 is the schematic diagram that ordinary steel-mixes that built H beam is vertically split.
Figure 11 is the schematic diagram that Wavelike steel webplate built H beam is vertically split.
2. mixing prestressing force+vertical splicing:
Figure 12 is schematic diagram when ordinary steel-mixes built H beam application mixing prestressing force and vertical splicing.
Figure 13 is schematic diagram when Wavelike steel webplate built H beam applies mixing prestressing force and vertical splicing.
It compares above-mentioned legend to can be seen that for Wavelike steel webplate built H beam, applies prestressing force just in bottom plate
It seem an independent process;But it is entirely different that ordinary steel-, which mixes the case where combining,.It therefore, can be prefabricated in construction
Apply all or part of prestressing force when concrete floor, then by precast concrete bottom plate, Wavelike steel webplate and precast concrete
The vertical layered assembly of top plate can greatly reduce the steel Shu Zhangla workloads at scene in this way, improve factory prefabricating degree.