CN104652296B - To three across the method stepping into row reinforcing in ordinary reinforced concrete continuous girder bridge - Google Patents

Abstract

To three across the method stepping into row reinforcing in ordinary reinforced concrete continuous girder bridge, its step comprises, erection construction operating platform; In across backplate surface process; Jack is utilized to remove end bay bearing by after two end bay jack-up; Reduce jack height lower than end bay height of support, obtain the decreasing value of jack compared with end bay bearing by calculating; In across dead load moment of flexure unloading after paste and fixation steel plate; With jack by end bay jack-up, the end bay bearing of dismounting is reinstalled to original position; Reduce jack height, end bay is seated on end bay bearing again, then shifts out jack.The method take in across dead load moment of flexure unloading after strengthening with external bonding steel plate, make steel plate not only can participate in bearing carload and after add dead load, and can also participate in bearing unloaded dead load moment of flexure, effectively can improve the bending bearing capacity of girder, also comparatively fully play the material property of strengthening steel slab simultaneously; In work progress, jack reduces height can not affect bridge security.

Description

To three across the method stepping into row reinforcing in ordinary reinforced concrete continuous girder bridge

Technical field

The present invention relates to highway bridge, particularly a kind of to three across in ordinary reinforced concrete continuous girder bridge across by the affixing steel plate method of reinforcing after the unloading of dead load moment of flexure.

Background technology

Ordinary reinforced concrete continuous girder bridge is a kind of bridge type conventional in Short/Medium Span Bridge, it has that seam is few, the smooth-going advantage such as comfortable of good rigidity, driving, often the winner of Bridge type scheme comparison in (15 ~ 30) m span, most based on concrete box tee section.Three is the combination of comparatively common spanning across ordinary reinforced concrete continuous girder bridge, in general across span large compared with two end bay spans, in across span and the span ratio of end bay to be everlasting 1:0.5 ~ 0.8, so in across the major control position being bridge design, be also than the position being easier to go wrong in the actual operation of bridge.In across mid span moment be in across stressed key factor, after part three puts into effect across ordinary reinforced concrete continuous girder bridge, because the anti-bending bearing capacity of girder is not enough, when exceeding concrete ultimate tensile strength across the base plate flexural stress near span centre in girder, transverse crack is there will be across span centre base plate in girder, time serious, transverse crack runs through base plate, even extends upwardly to the edge of a wing.At this moment just need stepping into row strengthen maintenance in girder, to ensure safety and the durability of structure.

Reinforce across stepping into row in ordinary reinforced concrete continuous girder bridge three, the normal method adopted directly in girder across affixing steel plate on base plate.The defect of this reinforcement form is, steel plate has acted on the dead load moment of flexure on girder before can not participating in bearing reinforcing, can only participate in bearing the moment of flexure that carload causes, and after reinforcing, the anti-bending bearing capacity of girder improves limited; Compared with the tensile reinforcement that steel plate is existing with girder, its ess-strain relatively lags behind, and when ultimate limit state, its ess-strain does not far reach tensile strength design load, but reach its tension design strength across tensile reinforcement in girder, cause the material property that can not give full play to steel plate.

Summary of the invention

The object of this invention is to provide a kind of to three across the method stepping into row in ordinary reinforced concrete continuous girder bridge and reinforce, with overcome above-mentioned directly in girder across the defect that base plate sticking steel plate reinforcement method exists.

For achieving the above object, the present invention takes to reinforce three across the method for reinforcing the front rear affixing steel plate of dead load moment of flexure unloading existed across in ordinary reinforced concrete continuous girder bridge, and its construction sequence is as follows:

Step 1, in girder across lower erection construction operating platform;

Step 2, the position of affixing steel plate is needed to process in girder across base plate

First fracture carries out embedding; Cut the thick concrete surface layer of 2 ~ 8mm after reaching curing time, solid concrete inner layer is exposed; Then gently cutting with cutting axe the concrete surface exposed, forming neat matsurface; Dust on removing surface; The more serious uneven epoxy resin mortar of effects on surface is repaired;

Step 3, on two end bay bridge piers of girder, for benchmark is respectively symmetrical, two jack are installed with bridge center line, utilize jack by two of girder end bay jack-up, make it exceed end bay bearing 0.5 ~ 2cm, the girder dead load that reason end bay bearing is born is turned and is born by jack; Then end bay bearing is removed;

Step 4, to unload across dead load moment of flexure in girder

Reduce the height of jack, make it lower than the height of end bay bearing, after jack height reduction, the end bay downwarp thereupon of girder, utilize the end bay downwarp of girder in across the hogging moment produced, centering carries out all or part of unloading across dead load moment of flexure;

For guaranteeing the safety of jack height lower than end bay height of support axle casing, jack is tried to achieve by following formula compared with the reduction height a of end bay bearing:

a＝min{a ₁,a ₂,a ₃,a ₄}

Wherein, a ₁for making to reach capacity anti-bending bearing capacity M across bearing place hogging moment in girder _utime jack compared with end bay bearing reduction height (mm), a ₁tried to achieve by following formula:

$a_1=(M_u-1.2M_1)/\left(1.2\stackrel{\‾}{M}\right)$

In formula:

M _u: in across the Ultimate Bearing Capacity (Nmm) of bearing place girder, tried to achieve by " highway reinforced concrete and prestressed concrete bridge contain design specifications " (JTGD62-2004) the 5.2nd article,

M ₁: in across in bearing place girder across dead load moment of flexure (Nmm), calculate try to achieve by setting up bridge structural mechanics model or bridge construction FEM (finite element) model,

every 1mm jack compared with end bay bearing reduction height in across produce moment of flexure (Nmm);

A ₂for the upper limb across bearing place girder in making reaches maximum crack width limit value W _utime jack compared with end bay bearing reduction height (mm), a ₂tried to achieve by following formula:

$a_2=\frac{W_u{E}_s\frac{0.87A_s{h}_0}{1.5C_1}\left(\frac{0.28+10\mathrm{\ρ}}{30+d}\right)-M_1}{\stackrel{\‾}{M}}$

In formula:

W _u: maximum crack width limit value, I class and II class environment maximum crack width limit value are 0.2mm, and III class and IV class environment maximum crack width limit value are 0.15mm,

E _s: the modulus of elasticity (N/mm of longitudinal tensile reinforcing bar ²), to R235 reinforcing bar E _s=2.1 × 10 ⁵n/mm ², to HRB335 reinforcing bar E _s=2.0 × 10 ⁵n/mm ²,

A _s: in across the upper limb longitudinal tensile area of reinforcement (mm of bearing place girder ²),

H ₀: in across the effective height (mm) of bearing place girder,

C ₁: rebar surface form coefficient, plain steel-bar, C ₁=1.4; Ribbed Bar, C ₁=1.0,

ρ: longitudinal tensile rebar ratio, when girder section is rectangle, wherein b is breadth of section (mm); When girder section is T-shaped, wherein b is cross section web width (mm), b _ffor the width (mm) of component tension flange, h _ffor the thickness (mm) of component tension flange; As calculated value ρ > 0.02, get ρ=0.02, during ρ < 0.006, get ρ=0.006,

D: longitudinal tensile bar diameter (mm),

A ₃for can offset in girder across the jack of span centre dead load moment of flexure compared with end bay bearing reduction height (mm) (this reduction height in across the moment of flexure produced across dead load moment M in lucky counteracting ₂), a ₃tried to achieve by following formula:

$a_3=M_2/\stackrel{\&OverBar;}{M}$

In formula:

M ₂: across span centre dead load moment of flexure in girder, calculated by the model of structural mechanics or bridge construction FEM (finite element) model setting up bridge and try to achieve (Nmm);

A ₄for the maximum height (mm) that jack can reduce compared with end bay bearing, a ₄tried to achieve by following formula:

a ₄＝t-t ₁

In formula:

T: end bay height of support (mm),

T ₁: the minimum constructive height (mm) of jack;

Step 5, in girder across on base plate paste and fixation steel plate

Across after the unloading of dead load moment of flexure in girder, first the adhesive surface of steel plate is cleared up, make adhesive surface occur metallic luster, then through polishing, form coarse adhesive surface, with acetone, adhesive surface is wiped clean; Then paste and fixation steel plate with cementing agent: cementing agent adopts epoxies cementing agent, and spread upon by cementing agent across on concrete floor and steel plate adhesive surface in processed good girder, smearing thickness is 1 ~ 3mm simultaneously; Then steel plate is affixed on precalculated position; After pasting steel plate, knock steel plate gently, as without empty sound, represent and pasted closely knit, have empty sound, indicates air, do not paste closely knit, should steel plate be peeled, again paste after benefit cementing agent; Steel sticking is well shored later immediately, shore pressure and keep 0.05 ~ 0.1MPa, cementing agent is made just to extrude as degree is (if fix with expansion bolt from the side seam of steel plate, now expansion bolt is the permanent additional anchor of steel plate, expansion bolt bury underground hole and steel plate boring need complete before smearing cementing agent), then under 20-25 DEG C of normal temperature, make adhesive cures 24 hours, setting up period must not have any disturbance to steel plate; Support is removed after solidification;

Step 6, complete steel sticking and fixing after, utilize jack by two of girder end bay jack-up, make two of girder end bays exceed end bay height of support 0.5 ~ 2cm, the end bay bearing then step 3 removed reinstalls to original position;

Step 7, reduction jack height, make the end bay of girder again be seated on end bay bearing, the girder dead load born by jack turns to be born by end bay bearing; Then shift out jack, so far complete three across in plain bars continuous girder bridge across the construction of dead load moment of flexure unloading consolidation.

Compared with prior art, the invention has the beneficial effects as follows:

1, by reinforcing across affixing steel plate after the unloading of dead load moment of flexure in girder, make the steel plate of stickup not only can participate in bearing carload and after add dead load, and can also participate in bearing with jack height decline unload in across dead load moment of flexure, effectively can improve the bending bearing capacity of girder;

2, by reinforcing across affixing steel plate after the unloading of dead load moment of flexure in girder, make to be reduced across the strain stress of tensile region reinforcing bar in girder, effectively solve the problem that strengthening steel slab ess-strain relatively lags behind, comparatively can give full play to the material property of steel plate;

3, jack is determined by calculating compared with the numerical value of the reduction height of end bay bearing, can guarantee that the safety of the girder when implementing jack and reducing highly is unaffected;

4, this reinforcement means adopts conventional construction equipment, technical maturity, and site operation is easy, and cost is low, is especially applicable to below under-clearance 10m, sets up operating platform easily three across the reinforcing of plain bars continuous girder bridge.

Accompanying drawing explanation

Fig. 1 is the longitudinal work progress schematic diagram of the present invention along bridge, and wherein Fig. 1 (a) is the schematic diagram of construction sequence 1,2; Fig. 1 (b) is the schematic diagram of construction sequence 3,4,5; Fig. 1 (c) is the schematic diagram of construction sequence 6,7;

Fig. 2 is the profile at work progress end bay bridge pier place, wherein Fig. 2 (a) profile that is construction sequence 3 end bay bridge pier place (end bay bearing 2 dotted line represent remove); Fig. 2 (b) is the profile at construction sequence 4,5 end bay bridge pier place; Fig. 2 (c) is the profile at construction sequence 6 end bay bridge pier place; Fig. 2 (d) is the profile at construction sequence 7 end bay bridge pier place;

Fig. 3 is that wherein Fig. 3 (a) is girder dead load bending moment diagram across dead load moment of flexure unloading schematic diagram in girder; Fig. 3 (b) is the girder bending moment diagram after jack reduction height; Fig. 3 (c) is the girder displacement diagram after jack reduction height.

In figure: 1 – girder, 2 – end bay bearings, across bearing in 3 –, 4 – 1 end bay bridge piers, bridge pier in 4 – 2,5 – operating platforms, 6 – jack, 7 – cementing agents, 8 – steel plates.

Detailed description of the invention

Below in conjunction with drawings and Examples, the invention will be further described.

The present embodiment be to certain three across step in ordinary reinforced concrete continuous girder bridge row reinforce, as shown in Figure 1, this bridge places end bay bearing 2 on end bay bridge pier 4 – 1, across bearing 3 during middle bridge pier 4 – 2 is placed with, girder 1 by end bay bearing 2 and in support across bearing 3, the spanning of continuous girder bridge is combined as (14+20+14) m, and girder 1 adopts C40 concrete, and cross section is box-shaped, cross section height 1.4m, the wide 8.5m of top board, top board average thickness 22.5cm, the wide 4.5m of base plate; End bay bearing 2 and in be 350mm across the height of bearing 3, in be configured with 68 φ 28HRB335 longitudinal tensile reinforcing bars across bearing place girder upper limb, in across the effective height h of bearing place girder ₀=1345mm, across the Ultimate Bearing Capacity M of bearing 3 girder in being tried to achieve by " highway reinforced concrete and prestressed concrete bridge contain design specifications " (JTGD62-2004) the 5.2nd article _u=10325kNm.In there are many transverse cracks across base plate, maximum crack width is 0.45mm, needs centering anti-bend reinforced across carrying out after soleplate crack process.

Before construction, first set up the FEM (finite element) model of this bridge, by FEM (finite element) model try to achieve end bay bearing often reduce 1mm height in across the moment of flexure caused in across in bearing 3 place girder across dead load moment M ₁=3900kNm, across span centre dead load moment M in girder ₂=2461kNm, wherein and M ₁for hogging moment, M ₂for positive bending moment, during calculating, all get the absolute value of each moment of flexure.

Then according to the reduction height a=min{a of jack compared with end bay bearing ₁, a ₂, a ₃, a ₄, the value of a in work progress is determined by following calculating:

$a_1=(M_u-1.2M_1)/\left(1.2\stackrel{\&OverBar;}{M}\right)=(14939-1.2\&times;3900)/(1.2\&times;194)=44.1mm.$

Be in I class and II class environment based on this bridge, its maximum crack width limit value is 0.2mm; This cross section, place is straight web solid section, so case beam baseplate width equals cross section web width, then and b=4500mm; The HRB335 longitudinal tensile rebar surface form coefficient C adopted ₁=1.0, elastic modulus E _s=2.0 × 10 ⁵n/mm ²; Longitudinal tensile bar diameter d=28mm; The width b of component tension flange _f=8500mm, thickness h _f=225mm, in across the upper limb longitudinal tensile area of reinforcement A of bearing place girder _s=68 × 615.8 (mm ²),

Longitudinal tensile rebar ratio $\mathrm{\&rho;}=\frac{A_s}{{\mathrm{bh}}_0+(b_f-b)h_f}=\frac{68\&times;615.8}{4500\&times;1345+(8500-4500)\&times;225}=0.006,$

$\begin{array}{c}{a}_2=\frac{W_u{E}_s\frac{0.87A_s{h}_0}{1.5C_1}\left(\frac{0.28+10\mathrm{\&rho;}}{30+d}\right)-M_1}{\stackrel{\&OverBar;}{M}}\\ =\frac{0.2\&times;2.0\&times;{10}^5\&times;\frac{0.87\&times;68\&times;615.8\&times;1345}{1.5\&times;1.0}\left(\frac{0.28+10\&times;0.006}{30+28}\right)-3900\&times;{10}^6}{194\&times;{10}^6}\\ =19.4mm\end{array}$

According to M ₂=2461kNm, try to achieve:

$a_3=\frac{M_2}{\stackrel{\&OverBar;}{M}}=\frac{3900}{194}12.7mm.$

According to the height t=350mm of end bay bearing 2, the minimum constructive height t of jack 6 ₁=200mm, tries to achieve:

a ₄＝t-t ₁＝350-200＝150mm

According to the reduction height a=min{a of result of calculation determination jack compared with end bay bearing ₁, a ₂, a ₃, a ₄}=a ₃=12.7mm.

Then by following construction sequence complete to this three across in plain bars continuous girder bridge across reinforcing (composition graphs 1 and Fig. 2):

Step 1, in girder across lower erection construction operating platform 5.

Step 2, the position of affixing steel plate is needed to process in girder 1 across base plate

First fracture carries out embedding; Clear up the concrete surface layer in this region after reaching curing time, the foreign matters such as wipe oil, polishing salient angle, cuts the thick top layer of 2 ~ 8mm, exposes solid concrete inner layer; Then gently cutting on the concrete surface exposed with cutting axe, forming smooth matsurface, adopt oil-free compressed air to blow down or remove the dust on surface by the way that clear water rinses, after surperficial bone dry, being stained with acetone wipe surfaces with absorbent cotton; After process, if surface still has seriously uneven, repair with epoxy resin mortar.

Step 3, on two end bay bridge pier 4-1 with bridge center line for reference symmetry installs two jack 6, jack is utilized to push up on two of girder end bays, make it exceed end bay bearing 2 about 0.5 ~ 2cm, the girder dead load that reason end bay bearing is born turns to be born by jack; Then end bay bearing 2 is removed.

Step 4, to unload across dead load moment of flexure in girder 1

Reduce the height of jack 6, make the height of jack lower than end bay height of support 12.7mm; After jack height reduction, the end bay downwarp thereupon of girder, utilize the end bay downwarp of girder across the hogging moment produced in girder, centering all unloads across dead load moment of flexure.

Step 5, in girder 1 across on base plate paste and fixation steel plate 8

Complete in girder 1 across after the unloading of dead load moment of flexure, the adhesive surface of steel plate 8 is processed: as steel plate corrosion is not serious, sandblasting, sand face or flat grinder buffing method is adopted to make surface of steel plate occur metallic luster, polishing roughness is the bigger the better, polishing lines is as far as possible vertical with steel plate Impact direction, is then stained with acetone with degreasing cotton and wipes clean; As serious in steel plate corrosion, need first by appropriate salt acid soak 20 minutes, rusty scale is come off, then rinses with whitewash, neutralizing acid ion, finally goes out track with flat grinder buffing, then wipes clean with acetone; Then to be spread upon by the cementing agent 7 be made up of epoxy resin across on the adhesive surface of concrete floor and steel plate in processed good girder with spatula, smearing thickness is 2mm, and thick middle edge is slightly thin simultaneously; Then steel plate being affixed on precalculated position, if facade is pasted, for preventing trickling, one deck dewaxing glass wool cloth can being added; Bond after steel plate, knocked steel plate with hand hammer gently along sticking veneer, as without empty sound, represented and pasted closely knit, have empty sound, indicates air, do not paste closely knit, should steel plate be peeled, again paste after benefit cementing agent; Steel sticking is well shored with rod later immediately, shores pressure and keeps 0.1MPa, cementing agent is extruded just from the side seam of steel plate; Then under 25 DEG C of normal temperature, make adhesive cures 24 hours, setting up period must not have any disturbance to steel plate; Support is removed after solidification.

Step 6, complete steel sticking and fixing after, utilize jack by girder jack-up, make it exceed end bay height of support 2cm, the end bay bearing of former dismounting is reinstalled to original position.

Step 7, unload and reduce jack height, making the end bay of girder again be seated on end bay bearing, the girder dead load born is turned born by end bay bearing by jack; Then shift out the jack on end bay bridge pier, so far complete to three across in plain bars continuous girder bridge across reinforce whole constructions.

As shown in Figure 3, the present embodiment before reinforcing, girder dead load in this three-span continuous beam across generation positive bending moment M (+); During reinforcing, utilize jack to make the end bay downwarp of girder, make in three-span continuous beam across generation equal-sized hogging moment M (-), utilize this hogging moment centering all to unload across dead load moment of flexure.The steel plate pasted after unloading not only participate in bearing carload and after add dead load, but also participate in bearing the downwarp of girder end bay unload in across dead load moment of flexure, effectively improve the utilization rate of steel plate reinforcement ability; Make to be reduced across the strain stress of tensile region reinforcing bar in girder, after stressed together with strengthening steel slab, the initial value of stress strain reduces and the bending bearing capacity of girder is improved simultaneously.

Claims (1)

1. pairs three across the method stepping into row in ordinary reinforced concrete continuous girder bridge and reinforce, and it is characterized in that, comprises following construction sequence:

Step 1, in girder (1) across lower erection construction operating platform (5);

Step 2, the position of affixing steel plate is needed to process in girder (1) across base plate

First fracture carries out embedding; Cut the thick concrete surface layer of 2 ~ 8mm after reaching curing time, solid concrete inner layer is exposed; Then gently cutting with cutting axe the concrete surface exposed, forming neat matsurface; Dust on removing surface; The more serious uneven epoxy resin mortar of effects on surface is repaired;

Step 3, on two end bay bridge piers (4-1) of girder, for benchmark is respectively symmetrical, two jack (6) are installed with bridge center line, utilize jack by two of girder end bay jack-up, make it exceed end bay bearing (2) 0.5 ~ 2cm, the girder dead load that reason end bay bearing (2) is born is turned and is born by jack (6); Then end bay bearing (2) is removed;

Step 4, to unload across dead load moment of flexure in girder (1)

Reduce the height of jack, make it lower than the height of end bay bearing, after jack height reduction, the end bay downwarp thereupon of girder, utilize the end bay downwarp of girder in across the hogging moment produced, centering carries out all or part of unloading across dead load moment of flexure;

For guaranteeing the safety of jack height lower than end bay height of support axle casing, jack is tried to achieve by following formula compared with the reduction height a of end bay bearing:

a＝min{a ₁,a ₂,a ₃,a ₄}

Wherein, a ₁for making to reach capacity anti-bending bearing capacity M across bearing place hogging moment in girder (1) _utime jack compared with end bay bearing reduction height, a ₁tried to achieve by following formula:

$a_1=(M_u-1.2M_1)/\left(1.2\stackrel{\&OverBar;}{M}\right)$

In formula:

M _u: in across the Ultimate Bearing Capacity of bearing (3) place girder, tried to achieve by " highway reinforced concrete and prestressed concrete bridge contain design specifications " (JTGD62-2004) the 5.2nd article,

M ₁: in across in bearing (3) place girder across dead load moment of flexure, calculate try to achieve by setting up bridge structural mechanics model or bridge construction FEM (finite element) model,

every 1mm jack compared with end bay bearing reduction height in across produce moment of flexure;

A ₂for the upper limb across bearing place girder in making reaches maximum crack width limit value W _utime jack compared with end bay bearing reduction height, a ₂tried to achieve by following formula:

$a_2=\frac{W_u{E}_s\frac{0.87A_s{h}_0}{1.5C_1}\left(\frac{0.28+10\mathrm{\&rho;}}{30+d}\right)-M_1}{\stackrel{\&OverBar;}{M}}$

In formula:

W _u: maximum crack width limit value, I class and II class environment maximum crack width limit value are 0.2mm, and III class and IV class environment maximum crack width limit value are 0.15mm,

E _s: the modulus of elasticity of longitudinal tensile reinforcing bar, to R235 reinforcing bar E _s=2.1 × 10 ⁵n/mm ², to HRB335 reinforcing bar E _s=2.0 × 10 ⁵n/mm ²,

A _s: in across the upper limb longitudinal tensile area of reinforcement of bearing place girder,

H ₀: in across the effective height of bearing place girder,

C ₁: rebar surface form coefficient, to plain steel-bar, C ₁=1.4; To Ribbed Bar, C ₁=1.0,

ρ: longitudinal tensile rebar ratio, when girder section is rectangle, wherein b is breadth of section; When girder section is T-shaped, wherein b is cross section web width, b _ffor the width of component tension flange, h _ffor the thickness of component tension flange; As calculated value ρ > 0.02, get ρ=0.02, during ρ < 0.006, get ρ=0.006,

D: longitudinal tensile bar diameter,

A ₃for offsetting across the reduction height of the jack of span centre dead load moment of flexure compared with end bay bearing in girder, a ₃tried to achieve by following formula:

$a_3=M_2/\stackrel{\&OverBar;}{M}$

In formula:

M ₂: across span centre dead load moment of flexure in girder, calculated by the model of structural mechanics or bridge construction FEM (finite element) model setting up bridge and try to achieve;

A ₄for the maximum height that jack can reduce compared with end bay bearing, a ₄tried to achieve by following formula:

a ₄＝t-t ₁

T: end bay bearing (2) highly,

T ₁: the minimum constructive height of jack (6);

Step 5, in girder (1) across on base plate paste and fixation steel plate (8)

Across after the unloading of dead load moment of flexure in girder (1), first the adhesive surface of steel plate is cleared up, make adhesive surface occur metallic luster, then through polishing, form coarse adhesive surface, with acetone, adhesive surface is wiped clean; Then cementing agent (7) is used to paste and fixation steel plate: cementing agent adopts epoxies cementing agent, and spread upon by cementing agent across on concrete floor and steel plate adhesive surface in processed good girder, smearing thickness is 1 ~ 3mm simultaneously; Then steel plate is affixed on precalculated position; After pasting steel plate, knock steel plate gently, as without empty sound, represent and pasted closely knit, have empty sound, indicates air, do not paste closely knit, should steel plate be peeled, again paste after benefit cementing agent; Steel sticking is well shored later immediately, shores pressure and keeps 0.05 ~ 0.1MPa, and cementing agent is extruded just as degree from the side seam of steel plate, and then under 20-25 DEG C of normal temperature, make adhesive cures 24 hours, setting up period must not have any disturbance to steel plate; Support is removed after solidification;

Step 6, complete steel sticking and fixing after, utilize jack by two of girder end bay jack-up, make two of girder end bays exceed end bay height of support 0.5 ~ 2cm, the end bay bearing then step 3 removed reinstalls to original position;

Step 7, reduction jack height, make the end bay of girder again be seated on end bay bearing, the girder dead load born by jack turns to be born by end bay bearing; Then shift out jack, so far complete three across in plain bars continuous girder bridge across the construction of dead load moment of flexure unloading consolidation.