A kind of suspension rod syndeton for reinforcing PSC Continuous Box Girder Bridge and construction method
Technical field
The present invention relates to a kind of suspension rod syndeton for reinforcing PSC Continuous Box Girder Bridge and construction method (PSC: prestressed reinforced concrete), the ruggedized construction of this invention comprises suspension rod, contiguous block, linkage and is placed on the combination shaped steel on bridge floor center line, change PSC continuous girder bridge stress system and force-bearing situation by setting up suspension rod, thus improve its supporting capacity.By linkage, combination shaped steel is anchored on case back plate.Contiguous block is welded on combination shaped steel, and is connected with suspension rod, enables the lifting force of suspension rod be applied to case beam, thus carries out active enforcement to case beam.The present invention becomes in the PSC continuous girder bridge of suspension bridge or bowstring arch bridge after reinforcing: will combine shaped steel many places and girder anchoring, and avoid local damage, and effectively can improve the connection effect of suspension rod and girder.Tradition is set up in the reinforcement means of suspension rod, and the connection effect of suspension rod and girder is poor, and serious to case beam local damage.Combination shaped steel provides lifting force upwards to girder under the active force of suspension rod, enhances girder bending resistance, shear resistance, reduces girder bending-down distortion, and can suppress the development of crack in main beam.Combination shaped steel is arranged on bridge floor center line and also uses as dividing strip.This suspension rod syndeton can make that raising PSC continuous box girder bridge bearing ability is more efficient, simple, safety and economy.
Background technology
It is domestic and international at present that to carry out the main technique methods of strengthening reconstruction to bridge as follows:
1) increasing section reinforcing method: this method, by increasing the cross section of concrete component and increasing arrangement of reinforcement, improves the bearing capacity and stiffness of component.According to the difference of reinforcing object and requirement, can increasing section be main reinforcing, also can be increase arrangement of reinforcement for main reinforcing.Need guarantee in reinforcing that conjunction old and new concret is good.But this method shortcoming also clearly, in reinforcing, inevitably increase dead load, so the large span prestressed concrete Continuous Box Girder Bridge studied for the present invention is not very applicable.
2) bridge floor plate reinforcement method is thickeied: the method cuts original bridge deck pavement, again lays a layer concrete or steel concrete strengthening course.This method can repair the bridge deck having occurred the disease such as crack, stripping, can increase again the effective height of original girder, increases the bending resistance of girder, improves the load relieving system of hinged girder, thus improves the supporting capacity of bridge.But this method, owing to adding bridge deadweight, makes dead load moment of flexure increase more, and is still subject to the restriction of former bridge construction lower edge tensile zone reinforcing bar allowable stress, so reinforcement means is generally only applicable to across the less tee girder bridge in footpath or plate-girder.The method is not good for large span prestressed concrete Continuous Box Girder Bridge consolidation effect equally.
3) beam rib reinforcement method is increased: increase beam rib reinforcement method and be usually used in the reinforcing of T beam, for this kind of bridge, the lower end of beam can be widened, increase cross sectional area, and set up muscle of being advocated in as placed concrete cross section.But add dead load equally after increasing section, be not also suitable for large span prestressed concrete Continuous Box Girder Bridge and reinforce.
4) sticking carbon fiber reinforcing method: sticking carbon fiber reinforcing method utilizes cementing agent carbon fibre reinforced composite (CFRP) to be pasted onto beam body concrete surface, when beam body is subject to the mobile load such as automobile, crowd, carbon fiber and beam body concrete compatible deformation and jointly stressed, thus improve supporting capacity and the rigidity of bridge, serve reinforcement effect.But owing to needing in construction to paste at the bottom of reinforced composite to beam, need worker stands to smear cementing agent on support, operation is inconvenience very, and sticking Quality is difficult to be protected.Simultaneously, because reinforced composite only participates in work when bridge is subject to mobile load, belong to passive stressed, when reinforced composite plays a role, the beam body lower flexure strain be reinforced is often larger, therefore, when larger lower flexure strain has occurred large span prestressed concrete Continuous Box Girder Bridge, consolidation effect is undesirable.
5) setting up supporting member reinforcing method: when bridge capacity can not meet the demands, but when girder construction is substantially intact, in order to improve bearing capacity, can adopt the method increasing supporting member, the bearing capacity and stiffness of newly-increased component is larger.Must guarantee in construction that the connection between new and old component is reliable, make it jointly participate in stressed effect, this reinforcement means construction period is comparatively large to traffic impact, and there is the nonsynchronous problem of new and old member stress.
6) affixing steel plate reinforcement method: utilize epoxy resin series adhesive by steel sticking at the tension side of reinforced concrete structures or weak part, steel plate and original structure thing is made to form entirety jointly stressed, improve the bending resistance of works, shear resistance and rigidity, improve the reinforcing bar of original structure thing and concrete stress state, restriction crack progressing, thus the bearing capacity and the durability that improve bridge.Similar to sticking carbon fiber reinforcing method, affixing steel plate reinforcement method belongs to passive enforcement equally, is not also suitable for the large span prestressed concrete Continuous Box Girder Bridge that larger lower flexure strain occurs.
7) external prestressing strengthening method: external prestressing strengthening beam bridge is a kind of reinforcement means changing the original stress of beam body.When bridge construction Lack of support or need can consider when improving class of loading to adopt external prestressing strengthening method.This method arranges in beam external body to be applied with prestressed reinforcing bar or steel tendon, to improve the force-bearing situation of bridge.This method often needs at beam body prestressed anchor device, produces damage to beam body; There is the possibility transfinited in the excessive compressive stress in local, causes potential safety hazard.
8) bridge system reinforcing method is changed: this reinforcement means reduces girder internal stress by changing bridge, improve supporting capacity.As set up support or bridge pier under simply supported beam; Continuous beam is connected to become across simply supported beam by adjacent two.Often to set up bridge pier in operation under bridge in this reinforcement means construction, thus take under-clearance, affect traffic or bridge flood discharge.This reinforcing mode effect is better, is the common measures taken solving the overweight car of temporary traffic at present both at home and abroad.After loaded vehicle is current, then remove interim bridge pier or support.Syndeton in the present invention just for this kind of reinforcement means, as continuous girder bridge is become bowstring arch bridge and suspension bridge.
9) anchor spraying concrete reinforcing method: anchor spraying concrete reinforcing method utilizes mechanical injection high pressure, concrete at a high speed on the good steel mesh reinforcement of anchoring, makes its setting and hardening form reinforced concrete structure, increase former bridge construction strength and stiffness.But this kind of reinforcement means uses more in mortar flag stone Arch Bridges Strengthening, stone arch bridge Common Diseases can be solved preferably.
China's road Traffic Volume is rapid growth with socioeconomic development; Meanwhile, in specification, design load standard value was relatively low in the past causes a large amount of load carrying capacity of bridge relative deficiency, there is the potential safety hazard that can not be ignored.For the situation that current conventional bridge reinforcing method also comes with some shortcomings when improving large span prestressed concrete continuous box girder bridge bearing ability, the present invention with existing large span prestressed concrete box girder bridge for research object, collect and analyze the bridge defect and design defect that cause its Lack of support, designing a kind of suspension rod syndeton for reinforcing PSC Continuous Box Girder Bridge and construction method, making that raising PSC continuous box girder bridge bearing ability is more efficient, simple, safety and economy.
Summary of the invention
The object of the invention is to improve and reinforce PSC Continuous Box Girder Bridge benefit, designing a kind of suspension rod syndeton for reinforcing PSC Continuous Box Girder Bridge and construction method, following structural features of the present invention:
This method is the PSC continuous girder bridge of suspension bridge or bowstring arch bridge after being applicable to reinforcing, below for suspension bridge system, the reinforcement principle of suspension rod syndeton is described:
Together with case back plate 1 and combination shaped steel 2 are anchored at by vertical prestressed reinforcement 3 and linkage 15, cable 4, suspension rod 5 connects bridge tower 6 and combination shaped steel 2, bridge tower 6 is welded on combination shaped steel 2, cable 4 is anchored at case beam 10 two ends, suspension rod 5 provides vertical lifting force to combination shaped steel 2, combination shaped steel 2 is made to be subject to vertical lifting power, due to anchorage effect, case back plate 1 is subject to vertical lifting power, cable 4 turns at the top of bridge tower 6, pressure is applied to bridge tower 6, bridge tower 6 by force transmission to the combination shaped steel 2 above bridge pier, load is passed to case beam No. 0 block 8 by combination shaped steel 2 again, No. 0 block 8 bears force transmission to central bearing point bearing 9, then ground is passed to by bridge pier 10 and basis 11.The structure of such design makes to avoid the adverse effect to girder, makes again girder directly receive lifting force upwards.Thus strengthen the bending resistance of PSC continuous box girder bridge girder, shear resistance, reduce girder bending-down distortion, and the development of crack in main beam can be suppressed.
Suspension rod syndeton comprises:
Case back plate 1, combination shaped steel 2, vertical prestressed reinforcement 3, cable 4, suspension rod 5, bridge tower 6, boring 7, No. 0 blocks 8, central bearing point bearing 9, bridge pier 10, basis 11, vertically steel plate 12, lower horizontal steel plate 13, upper horizontal steel plate 14, linkage 15, contiguous block 16, contiguous block bolt 17, case beam 18.
Before reinforcing, case beam 18 acts on bridge pier 10, and bridge pier 10 acts on basis 11, and basis 11 acts on ground, and case beam 18, bridge pier 10 and basis 11 form the three stride continuous box girder bridge of standard.
Combination shaped steel 2 is welded by vertical steel plate 12, lower horizontal steel plate 13, upper horizontal steel plate 14, linkage 15, contiguous block 16.Case beam 18 is PSC material structure.Use machinery to get boring 7 on lower horizontal steel plate 13, linkage 15 is passed, and is connected with vertical prestressed reinforcement 3, combination shaped steel 2 and the anchoring of case back plate 1 are integrated by recycling linkage 15.
Suspension rod 5 upper end is connected with galvanized wire for suspension bridge 4, lower end by contiguous block bolt 17 be welded on the contiguous block 16 combined on shaped steel 2 and be connected, provide lifting force to case beam 18.
According to the architectural feature of above invention, its construction method is as follows:
On the standard three stride continuous box girder bridge of case beam 18, bridge pier 10 and basis 11 composition, process combination shaped steel 2 and upper horizontal steel plate 14 by Fig. 7, wherein go up horizontal steel plate 14 and be finally welded on combination shaped steel 2 in construction.Boring 7 is got at combination shaped steel 2 design attitude.Utilize linkage 15 to connect vertical prestressed reinforcement 3, after bridge floor center line arrangement combinations shaped steel 2, combination shaped steel 2 is anchored on case back plate 1 by recycling linkage 15.
The contiguous block 16 processed is welded on combination shaped steel 2.Contiguous block bolt 17 is utilized to connect suspension rod 5 and contiguous block 16.
Adjust each steeve tension according to bridge specific constructive form and degree of disease, make bridge be in good stress.Finally install, weld horizontal steel plate 14, and antirust treatment is carried out to all steel beam column.
Beneficial effect of the present invention:
The present invention is a kind of suspension rod syndeton for reinforcing PSC Continuous Box Girder Bridge and construction method, by combination shaped steel, suspension rod, contiguous block, linkage to the reinforcement effect of PSC Continuous Box Girder Bridge, Continuous Box Girder Bridge is made to reach the effect of active enforcement, overcome traditional reinforcement means consolidation effect poor, to the damaged shortcoming such as large of former bridge construction local location, can effectively improve girder bending resistance, shear resistance, reduce girder bending-down distortion, and suppress the development of crack in main beam.
The machinery related in the present invention, material are very general in bridge construction, and the practicality of this reinforcement means is guaranteed.The processing that is prefabricated in the factory such as combination shaped steel, anchor block, contiguous block, suspension rod etc., in-site installation, crudy can be protected, and can effective reduction of erection time.Construction area mainly, in deck centre dividing strip region, occupies little space, and uninterrupted traffic is little to traffic impact, is applicable to the bridge strengthening that traffic task amount is large.
Accompanying drawing explanation
Fig. 1 reinforce first three across PSC Continuous Box Girder Bridge along bridge to sectional structural map;
Fig. 2 reinforces front PSC Continuous Box Girder Bridge cross-sectional view;
Fig. 3 reinforces rear suspension bridge system bridge elevation;
Fig. 4 reinforces rear suspension bridge system bridge 1/2 elevation;
Fig. 5 reinforces rear cabinet beam cross-sectional view;
In Fig. 6 a be suspension rod and contiguous block along bridge to schematic diagram;
B is suspension rod and contiguous block direction across bridge schematic diagram;
Fig. 7 combines shaped steel and upper horizontal steel plate figure.
Case back plate 1, combination shaped steel 2, vertical prestressed reinforcement 3, cable 4, suspension rod 5, bridge tower 6, boring 7, No. 0 blocks 8, central bearing point bearing 9, bridge pier 10, basis 11, vertically steel plate 12, lower horizontal steel plate 13, upper horizontal steel plate 14, linkage 15, contiguous block 16, contiguous block bolt 17, case beam 18.
Detailed description of the invention
Below in conjunction with the drawings and specific embodiments, the present invention is further described;
A kind of suspension rod syndeton for reinforcing PSC Continuous Box Girder Bridge utilizing above-mentioned design and construction method, concrete steps are as follows:
Step one: inspection information also actual measurement obtains bridge structure, disease conditions, exploration obtains the bearing capacity size that pre-reinforcement bridge needs to improve, be used for obtaining the stressing conditions of Construction of Pylon of Long Span Suspension Bridge or bowstring arch bridge arch rib, combination shaped steel, suspension rod, contiguous block, linkage, determine the required number of each parts, size, steel grade and concrete deployment scenarios thus.
Step 2: by form of structure determination hanger erection order and each the pulling force of the stressing conditions obtained in step one and suspension rod, contiguous block, combination shaped steel.
Step 3: consider job site mechanical work ability in the lump according to step, by factory process Construction of Pylon of Long Span Suspension Bridge or bowstring arch bridge arch rib (sections), combines shaped steel (sections).Size of holing is determined by linkage size.In single combination shaped steel segmental length, several boring 7 is got to lower horizontal steel plate 13.Cut bridge floor centerline deck paving, expose vertical prestressed reinforcement 3, utilize linkage 15 to connect vertical prestressed reinforcement 3, after bridge floor center line arrangement combinations shaped steel 2, combination shaped steel 2 is anchored on case back plate 1 by recycling linkage 15.
Step 4: be welded to connect block 16 at combination shaped steel 2 design attitude, utilizes contiguous block bolt 17 to be linked in sequence suspension rod 5.Strictly welding quality is controlled in construction.For reducing temperature to harmful effect that is assembled, welding quality, the time period of answering selective temperature moderate constructs.
Step 5: reinforcing process Bridge structural system changes, causes bridge construction internal force generation distribution again, therefore needs to adjust steeve tension.According to step 2, by designing requirement, suspension rod is installed, and adjusts steeve tension.The pulling force correctness of suspension rod is the important factor in order of consolidation effect, needs reliable method to measure the pulling force of each stage suspension rod, if any deviation, should adjust in time, in order to avoid unfavorable to bridge.
Step 6: upper horizontal steel plate 14, in the place punching that suspension rod 5 passes, welds with vertical steel plate 12 after splicing.Carry out anticorrosion, antirust treatment to all steel beam column, then continuous girder bridge has been reinforced.
The above, it is only preferred embodiment of the present invention, not any pro forma restriction is done to the present invention, anyly do not depart from technical solution of the present invention content, according to technical spirit of the present invention to any simple modification made for any of the above embodiments, equivalent variations and modification, all still belong in the scope of technical solution of the present invention.