CN205088583U - Bent cap truss -like reinforcing structure - Google Patents

Abstract

The utility model provides a bent cap truss -like reinforcing structure, fixes at the gooseneck between two piers respectively and installs the slant steel branch II between gooseneck and bent cap including slant steel branch I, the both ends of installing between pier side and bent cap, wherein slant steel branch I divide into two sections, by fusing rather than welded steel wedge pole. During the reinforcement, adopt jack pair slant steel branch I to rise in advance, then the steel wedge pole welding that will calculate out length according to formula make slant steel branch I in vertical ascending vertical component, the bent cap upper portion dead load of effectively uninstalling of providing two sections slant steel branches between I, constitute the bent cap truss -like system of consolidating jointly by slant steel branch I, slant steel branch II and gooseneck, effectively participate in the atress of bent cap, effectively participate in undertakeing the car load and add the effect that the dead load produced to the bent cap with the back.

Description

A kind of bent cap truss-like reinforcing construction

Technical field

The utility model relates to highway bridge, is specially a kind of bent cap truss-like reinforcing construction.

Background technology

Bent cap refers to as supporting, distribution and the load transmitting superstructure, at bridge pier, abutment or the ordinary reinforced concrete arranged on campshed or prestressed reinforced concrete structure.Because design standard is on the low side, increase the reason such as imposed load or automobile overload, part bent cap has occurred that in operation bending resistance, shearing resistance etc. are because of the stressed cracking disease caused, for ensureing that safety, the durability of structure need to reinforce.

For existing highway bridge, the bent cap reinforcement means of normal employing has affixing steel plate or carbon fiber method, Enlargement of Section etc., these reinforcement means all belong to passive enforcement, its weak point is, before later stage reinforcement material can not participate in bearing and reinforce, external loads is to the effect that bent cap produces, can only participate in bearing follow-up carload and after add the active force that dead load causes, the bearing power increase of bent cap is limited.

Active enforcement refer to this reinforcement measure can not only participate in bearing follow-up carload and after add the internal force that dead load causes, and can also participate in bearing the effect be applied on bent cap.Active enforcement, because effectively improving the supporting capacity of structure and enjoying the attention of people, becomes a current research topic.

Utility model content

The purpose of this utility model provides a kind of bent cap truss-like reinforcing construction, effectively to improve the supporting capacity of bent cap for this research topic.

For achieving the above object, the bent cap truss-like reinforcing construction that the utility model provides, comprise be arranged on oblique steel pole I between bridge pier side and bent cap by billet, two ends are separately fixed at the gooseneck between two bridge piers and are arranged on the oblique steel pole II between gooseneck and bent cap; Wherein oblique steel pole I is divided into two sections, is connected by with the gad bar of its welding.

Described oblique steel pole I is 30 ~ 45 ° with the angle of bridge pier.

The construction method of above-mentioned bent cap truss-like reinforcing construction, comprises the following steps:

Step one, between the cantilever end, bridge pier of bent cap, the side of bent cap bottom surface and bridge pier first processes installing the concrete surface at billet position by design and installation billet: removed by the broken segment of concrete surface, then dabbing is carried out, make aggregate exposure, remove floating dust with iron brush or compressed air, damaged portion epoxy available mortar is filled;

Then surfacing is carried out to billet, remove the greasy dirt on billet surface with gasoline cleaning, then with sand-blast or grinder buffing rust cleaning, make billet surface expose gloss, use gasoline scrub again, be finally coated with one deck epoxy resin grout on billet surface and it is protected;

Then concrete sticking veneer is after treatment buried the expansion bolt of a φ 8 ~ 12 underground every 20cm; Concrete surface and billet (cleaning with gasoline before pasting) are coated with the epoxide-resin glue that thickness is 3mm respectively, the installing hole that billet has been offered in advance is utilized to be pasted onto on concrete surface by billet by expansion bolt, tightening nuts immediately, pressurize, unnecessary epoxy resin adhesive liquid is extruded along billet edge, reaches tight stickup; Removal nut after epoxy resin adhesive liquid solidification, the shank of bolt exposed is stayed 2 ~ 3mm, and all the other are clipped, and carry out cold riveting.

Step 2, installation oblique steel pole I

Jack work backing plate on one end of two sections of oblique steel poles I is welded respectively, by design angle, the other end of two sections of oblique steel poles I is welded on the billet of the bent cap corresponding with oblique steel pole I upper and lower side and bridge pier respectively, the length of two sections of oblique steel poles I will guarantee that the reserved spacing d between its jack work backing plate is greater than the height of jack, and jack can be made to insert.

Step 3, utilize jack that gad bar is installed

The length L of gad bar ₁determined by following formula:

$L_1=(d+\frac{{\mathrm{VL}}_2}{E_2{A}_{2}sin\mathrm{\θ}})\×\frac{E_1{A}_{1}sin\mathrm{\θ}}{E_1{A}_1\sin \mathrm{\θ}-V}\left(mm\right)$

In formula:

V: the vertical force size (N) needing unloading,

E ₁: the modulus of elasticity (N/mm of gad bar material ²),

A ₁: the section area (mm of gad bar ²),

E ₂: the modulus of elasticity (N/mm of oblique steel pole I material ²),

A ₂: the section area (mm of oblique steel pole I ²),

L ₂: the total length (not comprising gad pole length) (mm) of oblique steel pole I,

θ: the angle of oblique steel pole I and bridge pier,

Reserved spacing (being greater than jack height) (mm) between the jack work backing plate of d: two sections of oblique steel poles I;

Jack (7) is arranged between the work backing plate of two sections of oblique steel poles I, then jacking is carried out, the length of the jack aspect ratio gad bar after jacking should be greater than 10mm (being convenient to install gad bar) but must not more than 20mm (guaranteeing that jacking does not damage bent cap), and jacking stops jacking after reaching requirement height;

Then between the jack work backing plate two gad bars being placed in respectively oblique steel pole I, the both sides of jack, after jack oil return, the power of bent cap passes to gad bar from jack, makes gad bar compacted; Then withdraw from jack, the two ends of gad bar are welded with the jack work backing plate of oblique steel pole I, make two sections of oblique steel poles I be fixedly connected with integral.

Gooseneck between step 4, installation bridge pier and oblique steel pole II

The two ends of gooseneck to be welded on the billet of bridge pier side (can a billet public with oblique steel pole I); Then the two ends of oblique steel pole II are pressed design angle and weld (can a billet public with oblique steel pole I) respectively with gooseneck and the bent cap billet corresponding with it.

The beneficial effects of the utility model:

1, adopt jack to apply pre-applied force to the oblique steel pole I of bridge pier side, bent cap top dead load can be unloaded, effectively reduce top dead load to lid beam action.

2, the gad pole length determined by design formulas because of be greater than oblique steel pole I jack work backing plate between reserved spacing, thus (size is can to make oblique steel pole I on himself direction, there is axial compression ), this axial compression not only makes oblique steel pole I be fixed between bent cap and bridge pier safely and reliably, and at the vertical component vertically provided upwards, size is V, bent cap is effectively unloaded.

3, oblique steel pole I, oblique steel pole II and gooseneck composition bent cap truss-like reinforcement system, can effectively participate in the stressed of bent cap, participate in bearing carload and after add the effect that dead load produces bent cap.

4, the oblique steel pole I under bent cap cantilever and span centre and oblique steel pole II employing are arranged symmetrically with, and can not produce extra transverse bending moment to bridge pier, total vertical force of bridge pier also can not change.

Accompanying drawing explanation

Fig. 1 is the schematic diagram of the utility model bent cap truss-like reinforcing construction;

Fig. 2 is the reference diagram of the utility model construction method step one;

Fig. 3 is the reference diagram of the utility model construction method step two;

Fig. 4 is the reference diagram of the utility model construction method step three and four;

Fig. 5 is the reference diagram of the utility model construction method step three and four.

In figure: 1 – bent cap, 2 – bridge piers, 3 – billets, 4 – oblique steel pole I, 5 – jack work backing plates, 6 – gad bars, 7 – jack, 8 – goosenecks, 9 – oblique steel poles II

Detailed description of the invention

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

The present embodiment is carry out truss-like reinforcing to the queen post bent cap of certain highway bridge bridge pier.The long 16.3m of bent cap 1 of this highway bridge bridge pier 2, high 1.5m, wide 1.8m, the long 3.25m of cantilever end, bridge pier spacing 8.3m, bridge pier 2 is the square column of length of side 150cm.

There are many Vertical Cracks at top of bridge pier place bent cap upper limb before reinforcing, maximum crack width reaches 0.37mm, and be the crack that bending resistance deficiency causes, crack width exceedes specification permissible value, needs to reinforce.

When carrying out anti-bend reinforced to this pier cap beam, below the bent cap apart from bridge pier 2 center line 2.7m, need the vertical force V=325kN applying unloading, to unload the part hogging moment of bridge pier place bent cap upper limb, make crack width value meet code requirement.

Reinforce the round steel pipe that the oblique steel pole I 4 used adopts external diameter 351mm, wall thickness 16mm, section area A ₂for 16838.94mm ², the elastic modulus E of material ₂be 2.06 × 10 ⁵n/mm ², the total length L of two sections of oblique steel poles I ₂for 2300mm, wherein going up segment length is 1150mm, and lower segment length is 1150mm.

The oblique steel pole II 9 used adopts the round steel pipe of external diameter 351mm, wall thickness 16mm, and length is 2757.7mm (single oblique steel pole II length), the elastic modulus E of material ₂be 2.06 × 10 ⁵n/mm ².

Gooseneck 8 specification used is I36 i iron, long 8.3m.

The billet 3 used is the Q235 steel plate of 700mm × 360mm × 16mm.

The jack work backing plate 5 used is the Q235 steel plate of 360mm × 360mm × 16mm.

Reinforcing jack 7 height used is 400mm.

Angle theta between oblique steel pole I and bridge pier takes 45 degree, and the jack work backing plate mutual spacing of two sections of oblique steel poles I is 425.7mm.

Reinforce the round steel pipe that the gad bar 6 used adopts external diameter 203mm, wall thickness 16mm, the section area A of gad bar ₁for 9399.65mm ², the elastic modulus E of gad bar material ₁be 2.06 × 10 ⁵n/mm ²,

Length according to gad pole length design formulas gad bar:

$L_1=(d+\frac{{\mathrm{VL}}_2}{E_2{A}_{2}sin\mathrm{\θ}})\×\frac{E_1{A}_{1}sin\mathrm{\θ}}{E_1{A}_1\sin \mathrm{\θ}-V}=426.57\left(mm\right)$

Reinforce and carry out according to the following steps:

Step one, installation billet

Billet is arranged on respectively: the cantilever end bottom surface of bent cap is apart from bent cap bottom surface between bridge pier center line 2.7m place, bridge pier apart from bridge pier center line 2.7m place and the bridge pier both sides apart from bent cap bottom surface 1.95m;

First the concrete surface installing billet position is processed: the broken segment of concrete surface is removed, then carries out dabbing, make aggregate exposure, remove floating dust with iron brush or compressed air, damaged portion epoxy available mortar is filled;

Then surfacing is carried out to billet, remove the greasy dirt on billet surface with gasoline cleaning, then with sand-blast or grinder buffing rust cleaning, make billet surface expose gloss, use gasoline scrub again, be finally coated with one deck epoxy resin grout on billet surface and it is protected;

Then concrete sticking veneer is after treatment buried the expansion bolt of a φ 10 underground every 20cm; Concrete surface and billet (cleaning with gasoline before pasting) are coated with the epoxide-resin glue that thickness is 3mm respectively, the installing hole that billet has been offered in advance is utilized to be pasted onto on concrete surface by billet by expansion bolt, tightening nuts immediately, pressurize, unnecessary epoxy resin adhesive liquid is extruded along billet edge, reaches tight stickup; Removal nut after epoxy resin adhesive liquid solidification, the shank of bolt exposed is stayed 3mm, and all the other are clipped, and carry out cold riveting.

Step 2, installation oblique steel pole I:

Jack work backing plate on one end of two sections of oblique steel poles I is welded respectively, be on the 45 degree of billets other end of two sections of oblique steel poles I being welded on respectively the bent cap corresponding with oblique steel pole I upper and lower side and bridge pier by oblique steel pole I and the angle theta between bridge pier, the jack work backing plate mutual spacing making two sections of oblique steel poles I is 425.7mm.

Step 3, utilize jack work backing plate to be arranged on by jack between two sections of oblique steel poles I, then carry out jacking, when the jack overall height after jacking reaches 440mm, stop jacking; Then between the jack work backing plate two gad bars being placed in respectively oblique steel pole I, the both sides of jack, after jack oil return, the power of bent cap passes to gad bar from jack, makes gad bar compacted; Then withdraw from jack, the two ends of gad bar are welded with the jack work backing plate of oblique steel pole I, make two sections of oblique steel poles I be fixedly connected with integral.

Step 4, installation gooseneck and oblique steel pole II

The two ends of gooseneck are welded on respectively on bridge pier side, the billet shared with oblique steel pole I; Then oblique steel pole II and the public billet of oblique steel pole I are welded on bent cap bottom surface, lower end is welded on gooseneck.

Reinforcing operation is carried out according to above step, the vertical force component of 325kN can be provided at oblique steel pole I pair of bent cap supporting-point place, this vertical force component can reduce the hogging moment at bent cap upper limb place of top of bridge pier place, improve structure stress, reduce crack width, make crack width meet code requirement, ensure the durability of structure.Bent cap bending resistance after reinforcing, shear behavior improve, and effectively can improve the rigidity of bent cap structure simultaneously.

Claims (2)

1. a bent cap truss-like reinforcing construction, it is characterized in that, comprise be arranged on oblique steel pole I (4) between bridge pier (2) side and bent cap (1) by billet (3), oblique steel pole II (9) that two ends are separately fixed at the gooseneck (8) between two bridge piers (2) and are arranged between gooseneck and bent cap; Wherein oblique steel pole I is divided into two sections, is connected by with the gad bar (6) of its welding.

2. bent cap truss-like reinforcing construction according to claim 1, is characterized in that, described oblique steel pole I is 30 ~ 45 ° with the angle of bridge pier.