CN205501789U - Broad width box girder bridge girder bottom plate structure - Google Patents

Abstract

The utility model provides a broad width box girder bridge girder bottom plate structure has end longeron that sets up along the bridge lateral separation and the bottom plate thickening crossbeam that sets up along bridge longitudinal separation on the upper portion of the bottom plate of arranging bottom plate prestressing steel section, be arranged in bottom plate below the bottom plate prestressing steel have with bottom plate thickening crossbeam is corresponding, transversal arrangement's prestressing without bondn reinforcing bar, and the top surface of crossbeam is thickeied in both ends anchor after be close to girder web department kickup, pass bottom plate thickening crossbeam of prestressing without bondn reinforcing bar at the bottom plate. Can make the reinforcing of bottom plate rigidity through this girder bottom plate structure, the bottom plate prestressing steel's that the bottom plate receives radial force can be offset basically to the prestressing without bondn reinforcing bar, and the two combination can prevent effectively that the bottom plate receives the radial force effect to take place to burst apart the deformation.

Description

A kind of wide box girder bridge girder base arrangement

Technical field

This utility model relates to highway bridge, particularly a kind of wide box girder bridge girder base arrangement.

Background technology

Wide box beam bridge described in the utility model refer to base plate average thickness (base plate thickness at girder span centre with at girder root The meansigma methods of thickness sum at place) be baseplate width 1/50～1/20 single box single chamber prestressed concrete continuous beam and prestressing force Concrete continuous rigid structure bridge.

The girder of this wide box beam bridge easily bursts apart because following reason causes its base plate to neutralize after bridge puts into operation in construction:

Girder height at span centre and limit fulcrum is less, and at central bearing point, height is relatively big, and the deck-molding at central bearing point is typically with parabola Form deck-molding transition at span centre and limit fulcrum, makes base plate form curved surface (see Fig. 1)；Baseboard prestress steel bar arrangement is in base plate In, the layout shape on its facade is similar to base plate, the most curvilinear；In construction, curved baseboard prestress reinforcing bar is to open Pulling force N_pBase plate can be produced radial force (see Fig. 2), because base plate average thickness is too small with the ratio of baseplate width, base plate after stretch-draw Slenderness ratio excessive, make foolrstiffness not enough, construction neutralizes after bridge puts into operation base plate in the radial force of baseboard prestress reinforcing bar Under effect, it is susceptible to burst apart.

Prevent the traditional method of wide box beam bridge Bottom slab breaking, be to arrange at base plate to prevent collapsing reinforcing bar.The problem that the method exists, one It is that the anti-design collapsing reinforcing bar lacks foundation, collapses, including anti-, spacing, the anti-reinforcing bar etc. collapsing reinforcing bar used whether reinforcing bar arranges, arranges Level and diameter etc. are all without directly regulation；Two is to prevent in construction that collapsing reinforcing bar is difficult to clasp completely the corrugated tube of baseboard prestress reinforcing bar, no Easily play a role；Three is to solve the problem that base plate stiffness by itself is not enough.

Utility model content

The defect existed for the above-mentioned traditional method preventing wide box beam bridge Bottom slab breaking, the purpose of this utility model is to provide one Plant the wide box girder bridge girder base arrangement that can effectively prevent base plate from bursting apart.

The wide box girder bridge girder base arrangement that this utility model provides, on the top of the base plate being disposed with baseboard prestress lengths of rebar The bottom girder being horizontally arranged at interval along bridge and the base plate along the longitudinally spaced setting of bridge is had to thicken crossbeam；It is being positioned at baseboard prestress reinforcing bar Following base plate has, the no-cohesive prestressed reinforcement of lateral arrangement corresponding with described base plate thickening crossbeam, prestressing without bondn The two ends of reinforcing bar are anchored at base plate by anchorage after being bent upwards at girder web plate, thickening crossbeam through base plate and thicken crossbeam End face.

Described base plate thickeies the crossbeam mutual spacing s along bridge longitudinal direction_vSpan be: 150cm≤s_v≤300cm；Base plate thickeies horizontal stroke Centre-height d of beam₂Span be: (K/15-d_j)≤d₂≤(K/10-d_j), in formula, K is baseplate width, d_jPut down for base plate All thickness；

Centre-height d of described bottom girder₃Span be: d₂/4≤d₃≤d₂/2；

Horizontal spacing K between described bottom girder and between bottom girder and girder web plate₁Equal, its span is: 150cm≤K₁≤250cm；

In described base plate, the radical n of the no-cohesive prestressed reinforcement that corresponding single base plate thickeies crossbeam lateral arrangement is calculated by following formula Go out:

In formula

Int: bracket function, round off rule rounds,

σ_con,d: the control stress for prestressing design load (MPa) of baseboard prestress reinforcing bar,

A_p,d: the total cross-sectional area (mm of baseboard prestress reinforcing bar²),

σ_con,w: the control stress for prestressing design load (MPa) of no-cohesive prestressed reinforcement,

A_p1,w: the area of section (mm of single no-cohesive prestressed reinforcement²),

K: baseplate width (mm),

s_v: base plate thickeies the crossbeam mutual spacing along bridge longitudinal direction,

d₁: base plate thickness (mm),

a_p,w: the vertical dimension (mm) of no-cohesive prestressed reinforcement center of gravity to base plate bottom surface,

The circular curve radius (m) of r: base plate, when for other curve form, according toCalculating is taken, wherein l For curve chord length, β is the ratio of curve rise f and chord length l.

Described no-cohesive prestressed reinforcement is the UPS15.2E soap-free emulsion polymeization epoxy coating strand of diameter 18.1mm.

The construction method of above-mentioned wide box girder bridge girder base arrangement, comprises the following steps:

Step 1, pour girder

Complete to set up template, assembling reinforcement (including that girder, base plate thicken crossbeam and the reinforcing bar of bottom girder) after-pouring master by design Beam, base plate thicken crossbeam and the concrete of bottom girder；When pouring, pre-buried described lateral arrangement is placed in base plate in base plate and two ends and adds No-cohesive prestressed reinforcement in thick crossbeam；

Step 2, stretch-draw no-cohesive prestressed reinforcement

When the concrete strength that step 1 is poured reaches 90% design strength, stretch-draw no-cohesive prestressed reinforcement, stretch-draw terminates By anchorage, the two ends of no-cohesive prestressed reinforcement are anchored at the end face at the both ends of base plate thickening crossbeam afterwards；

Step 3, stretch-draw baseboard prestress reinforcing bar

After no-cohesive prestressed reinforcement stretch-draw, stretch-draw baseboard prestress reinforcing bar, terminates construction.

Compared with prior art, the beneficial effects of the utility model are:

(1) thickening crossbeam and bottom girder by base plate, make the rigidity of base plate strengthen, base plate is reduced by radial force effect deformation.

(2) the radical n that no-cohesive prestressed reinforcement calculates according to formula configures, can basic neutralisation stretch-draw baseboard prestress steel Radial force suffered by base plate during muscle, effectively prevents the Bottom slab breaking caused because of radial force effect.

(3) no-cohesive prestressed reinforcement selects the soap-free emulsion polymeization epoxy coating strand that external diameter is little, it is easy to lateral arrangement in the soleplate, It is not susceptible to conflict with baseboard prestress reinforcing bar and regular reinforcement.

Accompanying drawing explanation

Fig. 1 is the side view of wide box girder；

Fig. 2 is baseboard prestress reinforcing bar radial force schematic diagram；

Fig. 3 is along girder longitudinal direction partial sectional view；

Fig. 4 is A-A sectional drawing in Fig. 3；

Fig. 5 is B-B sectional drawing in Fig. 3；

Fig. 6 is C-C sectional view in Fig. 3；

Fig. 7 is D portion enlarged drawing in Fig. 3.

In figure: 1 girder, 2 base plates, 3 baseboard prestress reinforcing bars, 4 girder web plates, 5 bottom girders, 6 base plates add Thick crossbeam, 7 no-cohesive prestressed reinforcements, 8 anchorages.

Detailed description of the invention

Below in conjunction with drawings and Examples, this utility model is described further.

As it is shown in figure 1, the present embodiment wide box girder bridge girder base arrangement, wide box beam bridge is pre-stressed concrete and consecutive steel structures Bridge, base plate 2 is curved surface, and the baseboard prestress reinforcing bar 3 being placed in base plate 2 is the most curvilinear.Wide box girder bridge girder 1 across Degree is 180m, span centre deck-molding 4.5m, deck-molding 10.8m at central bearing point, baseplate width K=1140cm；Base plate thickness girder across Being 28cm at middle KZ, base plate thickness is 72cm at girder root GB, base plate average thickness d_j=50.0cm, for base plate width The 1/24 of degree, belongs to wide box beam bridge.

As it is shown on figure 3, span centre base plate curve chord length l=174.0m, the deck-molding of span centre and central bearing point can obtain rise F=10.8-4.5=6.3m, the circular curve radius of base plate

$r=\frac{l}{2}(\frac{1}{4\mathrm{\β}}+\mathrm{\β})=\frac{174}{2}\×(\frac{1}{4\×\frac{6.3}{174}}+\frac{6.3}{174})=603.9m.$

As shown in Figure 4 and Figure 5, base plate is disposed with 8 hole baseboard prestress reinforcing bars, the baseboard prestress steel in single duct altogether The area of section of muscle is 1668mm², total cross-sectional area A of 8 hole baseboard prestress reinforcing bars_p,d=13344mm², baseboard prestress Control stress for prestressing design load σ of reinforcing bar_con,d=1395MPa (the stretching force N of baseboard prestress reinforcing bar shown in Fig. 2_pRight with it Should).

As in figure 2 it is shown, curved baseboard prestress reinforcing bar is with stretching force N_pBase plate can be produced radial force after stretch-draw.Because of base plate Average thickness is too small with the ratio of baseplate width, and the slenderness ratio of base plate is excessive, makes foolrstiffness not enough, and construction neutralizes bridge and puts into fortune After row, under the radial force effect that baseboard prestress reinforcing bar produces, base plate is susceptible to deformation of bursting apart.

For preventing base plate from bursting apart deformation, as shown in Fig. 3 to Fig. 7, on the base plate top being disposed with baseboard prestress lengths of rebar Pour along bridge longitudinal direction mutual spacing s_vThe base plate of=1.8m thickeies crossbeam 6, and it is that class is trapezoidal that base plate thickeies section of beam, and base plate thickeies horizontal stroke Beam centre-height d₂=55cm；Thicken at base plate and pour along direction across bridge mutual spacing K between crossbeam₁=1.9m, centre-height d₃The bottom girder 5 of=20cm；The most corresponding each base plate thickeies the UPS15.2E of a diameter of 18.1mm of crossbeam lateral arrangement Soap-free emulsion polymeization epoxy coating strand is as no-cohesive prestressed reinforcement 7, and the two ends of no-cohesive prestressed reinforcement are near girder web plate 4 Place is bent upwards, thicken crossbeam through base plate after be anchored at base plate by anchorage 8 and thicken the end face of crossbeam.Single soap-free emulsion polymeization in advance should The area of section of power reinforcing bar is A_p1,w=140mm², control stress for prestressing design load is σ_con,w=1395MPa, prestressing without bondn Reinforcing bar center of gravity is a to the vertical dimension of base plate bottom surface_p,w=50mm.

As a example by shown in Fig. 4 section base plate, to 1#～6# totally 6 base plates being had to thicken crossbeam by section base plate.To should 6 Base plate is thickeied the radical n of the no-cohesive prestressed reinforcement in the base plate of crossbeam and is tried to achieve by calculated below:

Corresponding 6 base plates are thickeied the base plate thickness d of crossbeam₁Substitute into respectively in following formula:

Calculate corresponding 1#～6# base plate and thicken the radical n such as following table of the no-cohesive prestressed reinforcement in crossbeam base plate:

Base plate thickeies crossbeam numbering	1#	2#	3#	4#	5#	6#
							Base plate thickness d1(mm)	280	288	296	304	312	320
The radical n of no-cohesive prestressed reinforcement	4	4	4	4	4	4

From in table, for section base plate shown in Fig. 4, corresponding 1#～6# base plate thickeies the prestressing without bondn steel in crossbeam base plate Muscle is 4.

The radical of the no-cohesive prestressed reinforcement arranged in other parts of base plate is tried to achieve by same method.

The both ends of no-cohesive prestressed reinforcement are being bent upwards (as shown in Figure 4) at girder web plate 4, are adding through base plate It is anchored at base plate by anchorage 8 behind thick crossbeam two ends and thickeies the end face of crossbeam.

Above-mentioned kingpost baseplate structure is constructed according to the following steps:

Step 1, by having designed erection template, assembling reinforcement after-pouring girder, base plate thicken crossbeam and the concrete of bottom girder； When pouring, pre-buried lateral arrangement is partially disposed in base plate in base plate and bending two ends and thickeies the no-cohesive prestressed reinforcement in crossbeam；

Step 2, when step 1 casting concrete intensity reaches 90% design strength, stretch-draw no-cohesive prestressed reinforcement, adopt With anchorage, the two ends of no-cohesive prestressed reinforcement are anchored at base plate and thicken the both ends end face of crossbeam；

After step 3, no-cohesive prestressed reinforcement stretch-draw, stretch-draw baseboard prestress reinforcing bar, terminates construction.

Using this wide box girder bridge girder of above-mentioned kingpost baseplate structure, construction to neutralize after bridge puts into operation does not all occur base plate to collapse Split phenomenon.

Claims (3)

1. a wide box girder bridge girder base arrangement, it is characterised in that:

The bottom girder (5) being horizontally arranged at interval along bridge is had on the top of the base plate (2) being disposed with baseboard prestress reinforcing bar (3) section Crossbeam (6) is thickeied with the base plate along the longitudinally spaced setting of bridge；The base plate being positioned at below baseboard prestress reinforcing bar has and the described end Plate thickening crossbeam is corresponding, the no-cohesive prestressed reinforcement (7) of lateral arrangement, and the two ends of no-cohesive prestressed reinforcement are near main Web (4) place is bent upwards, thicken crossbeam through base plate after be anchored at base plate by anchorage (8) and thicken the end face of crossbeam.

Wide box girder bridge girder base arrangement the most according to claim 1, it is characterised in that:

Described base plate thickeies the crossbeam mutual spacing s along bridge longitudinal direction_vSpan be: 150cm≤s_v≤300cm；

Base plate thickeies centre-height d of crossbeam₂Span be: (K/15-d_j)≤d₂≤(K/10-d_j), in formula, K is base plate width Degree, d_jFor base plate average thickness；

Centre-height d of described bottom girder₃Span be: d₂/4≤d₃≤d₂/2；

Horizontal spacing K between described bottom girder and between bottom girder and girder web plate₁Equal, its span is: 150cm≤K₁≤250cm。

Wide box girder bridge girder base arrangement the most according to claim 2, it is characterised in that corresponding single in described base plate The radical n of the no-cohesive prestressed reinforcement that base plate thickeies crossbeam lateral arrangement is calculated by following formula:

$n=\mathrm{int}\[\frac{1}{8}\·\frac{{\mathrm{\σ}}_{con,d}{A}_{p,d}}{{\mathrm{\σ}}_{con,w}{A}_{p1,w}}\·\frac{{\mathrm{Ks}}_v}{(0.5d_1-a_{p,w})r}\]$

In formula

Int: bracket function, round off rule rounds,

σ_con,d: the control stress for prestressing design load of baseboard prestress reinforcing bar,

A_p,d: the total cross-sectional area of baseboard prestress reinforcing bar,

σ_con,w: the control stress for prestressing design load of no-cohesive prestressed reinforcement,

A_p1,w: the area of section of single no-cohesive prestressed reinforcement,

K: baseplate width,

s_v: base plate thickeies the crossbeam mutual spacing along bridge longitudinal direction,

d₁: base plate thickness,

a_p,w: the vertical dimension of no-cohesive prestressed reinforcement center of gravity to base plate bottom surface,

The circular curve radius of r: base plate, when for other curve form, according toCalculating is taken, and wherein l is bent Line chord length, β is the ratio of curve rise f and chord length l.