CN104195951B - Pull bar wedge bearing - Google Patents

Abstract

The present invention discloses a kind of pull bar wedge bearing setting up prestressed continuous beam No. 0 sections and precast box roof beam structure and adopt, comprise top board, right cone, base plate and left cone, top board and base plate are retrained by hexagon socket head cap screw nut and hexagon socket head cap screw, right cone and left cone are placed in the right between top board and base plate and the left side respectively, are connected with high strength nut by high strength thread, high strength pad.Tightening high strength nut makes top board rising support prestressed continuous beam No. 0 sections and precast box roof beam structure; when after closure of bridge structure or system transform; unclamp after high strength nut makes top board decline, the pull bar wedge bearing be erected under prestressed continuous beam No. 0 sections and precast box roof beam structure can be taken out of easily.Product configurations of the present invention is brief, decrement is little, overturning or slip resistance analysis, safe and reliable, environmental protection and cost performance high.

Description

Pull bar wedge bearing

Technical field

The present invention relates to the supporting apparatus that a kind of bridge (or structure) sets up engineering, be specially adapted to prestressed continuous beam No. 0 sections, pull bar wedge bearing that Precast T-Beam (case beam) sets up.

Background technology

In prestressed continuous beam No. 0 sections, prefabricated case beam (T beam) erection, according to the difference of design concept, sometimes need a kind of technique adopted.This process is as follows: first arrange temporary support at Dun Ding, then prestressed continuous beam No. 0 sections, prefabricated case beam (T beam) are erected on temporary support, though temporary support is a temporary works in bridge erection, really an extremely important and indispensable ring.Prestressed continuous bridge at cantilever pouring, free cantilever erection, full framing is cast-in-place completes, after bridge realizes closing up; After prefabricated case beam (T beam) has been erected at the operations such as wet joint, wet hinge seam, hogging moment stretch-draw and slip casting; Remove temporary support, complete system transform.Past has and to adopt brick, wedge shape wood to do temporary support, 3 kinds of methods that current China generally adopts and the shortcoming of existence as follows:

(1) sand cylinder/sandbox

Sand cylinder, sand box temporary support, by calculating the steel pipe manufacturing sand cylinder selecting diameter suitable, the shutoff of sand cylinder bottom welding steel plate, stay a screw hole in side and block with screw, appropriate fine sand is loaded in cylinder, the piston that one is slightly less than sand cylinder diameter is placed on fine sand top, and the steel pipe etc. that piston can select concrete, wood, steel plate to seal, makes its piston-top surface higher than sand cylinder 3-5CM.Releasing fine sand in bucket by unclamping bottom screw, reaching the object of removing temporary support, completing beam slab system transform.The shortcoming existed is: sand about carries 900KPa load pressure, and 90 tons of need 1 square meter left and right areas, apply without space for long-span continuous beam; Sand compress variation is large, must preset ± the height of 10mm, be unfavorable for Cantilever Construction case beam precision controlling; Domestic Zhejiang bridge once used 660t, but bulky, and pressure testing complex procedures, highly about 80cm, easily topple.

(2) resistance sulphur-bonded mortar

Sulphur-bonded mortar temporary support design principle, by pre-buried resistance wire in the sulphur-bonded mortar temporary support made by certain match ratio, can to soften the principle design of sulphur-bonded mortar after resistance wire energising.Adopt within the scope of the 5cm of bearing middle and lower part and establish sulphur-bonded mortar and pre-buried resistance wire, top adopts C50 concrete, namely with on bent cap contact surface spreads one deck malthoid in advance at the bottommost of bearing.After other operation completes, when needing to remove temporary support, pass to the constant current of 220V to the resistance wire be embedded in sulphur-bonded mortar layer, sulphur-bonded mortar is softened, top C50 concrete deadweight and the prefabricated fine strain of millet pressure in top effect under, slowly decline, precast beam drops to permanent bearing thereupon.

The shortcoming existed is: sulphur-bonded mortar bearing needs the hot melt that is energized, and adds potential safety hazard, more time-consuming, and is easy to have influence on the permanent bearing of rubber on side during heating, has infringement once in a while to Liang Tiye; From the viewpoint of environmental protection, sulphur boils surrounding environment influence very large, is that the rear smog produced of sulphur powder or heating all can produce harm to animal and plant; Sulphur-bonded mortar bearing is easily chipping can not be reused, and easily occur resistance wire electrical shorts and heat production uneven, be difficult to softening dismounting.

(3) static micro-explosion (splitting)

Prestressed continuous beam No. 0 sections adopts steel concrete temporary support mostly, after treating closure of bridge structure, then removes steel concrete temporary support.The shortcoming existed is: the time controling of method to microdilatancy explosive that presplitting cuts again is not easily grasped to adopt microdilatancy explosive to carry out; High-altitude suspention cuts concrete, and operating space is little, concrete chisel removal amount large, danger is high, and explosion simultaneously also easily destroys the stressed of box-beam structure.

Summary of the invention

The object of the invention is the temporary support problem in order to solve in bridge (or structure) erection process, provide a kind of construct brief, decrement is little, overturning or slip resistance analysis, safe and reliable, environmental protection and high erection prestressed continuous beam No. 0 sections of cost performance, prefabricated case beam (T beam) frame pull bar wedge bearing.

Technical scheme of the present invention is as follows:

A kind of pull bar wedge bearing, comprise top board, right cone, base plate and left cone, top board is placed on base plate, by hexagon socket head cap screw nut and hexagon socket head cap screw constraint, right cone and left cone are placed in the right between top board and base plate and the left side respectively, are connected with high strength nut by high strength thread, high strength pad; Tightening high strength nut makes top board rising support prestressed continuous beam No. 0 sections and prefabricated case beam (T beam) frame; when after closure of bridge structure or system transform; unclamp after high strength nut makes top board decline, the pull bar wedge bearing be erected under prestressed continuous beam No. 0 sections and prefabricated case beam (T beam) frame can be taken out of easily.

Described top board, right cone, base plate and left cone are cast by Q235 material and are formed, and surface is coated with two-layer MICA finish paint, every layer thickness 40 μm after adopting blasting craft; Described high strength thread, high strength pad and high strength nut adopt AISIA4340 steel, plating zinc on surface 50 μm; Described hexagon socket head cap screw nut and hexagon socket head cap screw adopt high strength steel, plating zinc on surface 50 μm.

The lozenges polishing of described top board, right cone, base plate and left cone, surface roughness is 0.8 ~ 1.6.

Described blasting craft reaches SA3 grade.

Described Q235 carbon structural steel is also known as at A3 plate.Q representative be the yield limit of this material, below 235, just refer to the yield value of this material, at about 235MPa.And its yield value can be reduced along with the increase of the thickness of material.Because carbon containing is moderate, combination property is better, and the performances such as intensity, plasticity and welding are better coordinated, and purposes is the most extensive.

Described sandblasting, English name: sandblasting utilizes the percussion cleaning of high speed sand flow and the process of alligatoring matrix surface; SA3 rank weighs the standard of cleannes, SA3 is divided into level Four, SA1, SA2, SA2.5, SA3, SA3 rank is industrial senior requirement process rank, the technical standard of SA3 process is the same with SA2.5 rank, but more thorough than the shade, corrosion etc. of the process of SA2.5 rank, these shade, corrosions etc. do not exist.

Described AISIA4340 is the one belonging to pinion steel, the trade mark: 4340, U.S. SAE standard 4340, AISI is same: UNSG43400, tensile strength sigma b (MPa): >=980 (100), yield strength σ s (MPa): >=835 (85), there are high intensity, toughness and outstanding quenching degree and anti-overheated stability, but susceptibility of flake formation is high, there is temper brittleness.Weldability is poor, needs through high temperature preheating before weldering, and postwelding need eliminate stress, and uses after modified.

Compared with existing sand cylinder (sandbox), resistance sulphur-bonded mortar, static micro-explosion (splitting) technology, pull bar wedge bearing of the present invention has the following advantages:

1, construct brief, top board, right cone, high strength pad, high strength nut, high strength thread, base plate, left cone and set bolt form, take up room little, using method is easy, and maintenance cost is low, easily replaces, quick detachable.

2, decrement is little, and steel beam column combines mutually, and decrement is little, very suitable precision controlling.

$\mathrm{\ΔL}=\frac{F_v\×h}{W_s\×A_{\min }}=\frac{1.5\×{10}^6\×150}{2.02\×{10}^5\×2.52\×{10}^4}=0.04\mathrm{mm}$

3, overturning or slip resistance analysis, bearing is horizontal high, and than about 1:1, length to height ratio is about 2:1, more than 2 temporary supports simultaneously side by side or π type arrange and use, overturning or slip resistance analysis, good stability.

4, safe and reliable, top board, base plate pressure-bearing, high-strength bolt tension, member parts is homogeneous controlled.Cast steel partial compression 150 ton hour, stress 59MPa, high-strength bolt 577MPa are safe and reliable.

Cast steel part ${\mathrm{\σ}}_{\max }=\frac{F_v}{A_{\min }}=\frac{4.5\×{10}^{6}N}{2.52\×{10}^4\mathrm{mm}}=59.52\mathrm{MPa}$

High strength thread stress ${\mathrm{\σ}}_{\max }=\frac{2f}{A_{\min }}=\frac{2\×1.417\×{10}^5}{\mathrm{\π}\×{12.5}^2}=577\mathrm{MPa}$

5, environmental protection, relative to sulphur-bonded mortar bearing, sandbox sand cylinder, concrete temporary support, on surrounding environment without impact; Health is succinct, without building waste; Low-carbon environment-friendly, recycles.

6, cost performance is high, and component casting technique is simple, and component market is all sold at a reasonable price, and acquisition cost is low.

Accompanying drawing explanation

Fig. 1 is the structural representation front view of pull bar wedge bearing of the present invention.

Fig. 2 is the structural representation left view of pull bar wedge bearing of the present invention.

Fig. 3 is the structural representation top view of pull bar wedge bearing of the present invention.

Title sequence number in figure is:

Top board 1, right cone 2, high strength pad 3, high strength nut 4, high strength thread 5, base plate 6, hexagon socket head cap screw nut 7, hexagon socket head cap screw 8, left cone 9.

Detailed description of the invention

Introduce the present invention in order to more detailed, below in conjunction with accompanying drawing, the present invention will be further described.

As shown in Figure 1 to Figure 3, a kind of pull bar wedge bearing, comprise top board 1, right cone 2, base plate 6 and left cone 9, top board 1 is placed on base plate 6, retrained by hexagon socket head cap screw nut 7 and hexagon socket head cap screw 8, right cone 2 and left cone 9 are placed in the right between top board 1 and base plate 6 and the left side respectively, are connected with high strength nut 4 by high strength thread 5, high strength pad 3; Tightening high strength nut 4 makes top board 1 rising support prestressed continuous beam No. 0 sections and prefabricated case beam (T beam) frame; when after closure of bridge structure or system transform; unclamp after high strength nut 4 makes top board 1 decline, the pull bar wedge bearing be erected under prestressed continuous beam No. 0 sections and prefabricated case beam (T beam) frame can be taken out of easily.

Using method of the present invention is: first, checks before installing: require the damage without any exterior visual and the damage from corrosion protection, ensure cleannes, bearing temporary fixed whether firmly, ensure that the parallelism of top 1 and base plate 6 supporting surface makes the direction vertical support plane of load; Be placed in again on Dun Ding, then prestressed continuous beam No. 0 sections, prefabricated case beam (T beam) are erected on bearing, after completing the operations such as cantilever pouring, free cantilever erection, full framing cast-in-place and wet joint, wet hinge seam, hogging moment stretch-draw and slip casting, remove bearing, complete system transform.

The present invention utilizes the unilateral constrain of high strength thread 5 to left cone 9, right cone 2 to obtain larger supporting capacity; Utilize the low-friction coefficient in angle steel face between top board 1, base plate 6 and left cone 9, right cone 2, acquisition top board 1, the vertical displacement that base plate 6 is larger, left cone 9, the horizontal movement that right cone 2 is larger; And pass through the torsional interaction of high strength thread 5, realize high tonnage jacking and fall unloading functions.Jacking Function implementation flow process: (1), top board 1 and base plate 6 are neatly stacked spelling, screw on hexagon socket head cap screw 8 and hexagon socket head cap screw nut 7; (2), by bearing drop to the ground and be sidelong, smear authentic high-quality at the chamfered portion of top board 1 and base plate 6 and lubricate anticorrosion grease, fill in left cone 9 and right cone 2 simultaneously; (3), by high strength thread 5 insert left cone 9 and right cone 2, high strength thread 5 installs high strength pad 3 and high strength nut 4, make top board 1 and base plate 6 exceed 5mm than left cone 9 and right cone 2; (5), tighten the torsional interaction of high strength nut 4 by high strength thread 5, realize top board 1 jacking 20mm.Fall when unloading, unclamp high strength nut 4, left cone 9 and right cone 2 are moved back toward both sides, realize top board 1 and to decline 20mm.

Application Example

The project of the BabahoyoBridge that Guangxi company undertakes the construction of recently, employs combined isolator of the present invention, completes erection prestressed continuous beam No. 0 sections and precast box roof beam structure easily, can build smoothly.

Claims (3)

1. a pull bar wedge bearing, it is characterized in that: comprise top board (1), right cone (2), base plate (6) and left cone (9), top board (1) is placed on base plate (6), by hexagon socket head cap screw nut (7) and hexagon socket head cap screw (8) constraint, right cone (2) and left cone (9) are placed in the right between top board (1) and base plate (6) and the left side respectively, are connected with high strength nut (4) by high strength thread (5), high strength pad (3); Tightening high strength nut (4) makes top board (1) rising support prestressed continuous beam No. 0 sections and precast box roof beam structure, when after closure of bridge structure or system transform, unclamp after high strength nut (4) makes top board (1) decline, the pull bar wedge bearing be erected under prestressed continuous beam No. 0 sections and precast box roof beam structure can be taken out of;

Described top board (1), right cone (2), base plate (6) and left cone (9) are cast by Q235 material and are formed, and surface is coated with two-layer MICA finish paint, every layer thickness 40 μm after adopting blasting craft; Described high strength thread (5), high strength pad (3) and high strength nut (4) adopt AISIA4340 steel, plating zinc on surface 50 μm; Described hexagon socket head cap screw nut (7) and hexagon socket head cap screw (8) adopt high strength steel, plating zinc on surface 50 μm.

2. pull bar wedge bearing according to claim 1, is characterized in that: the lozenges polishing of described top board (1), right cone (2), base plate (6) and left cone (9), surface roughness is 0.8 ~ 1.6.

3. pull bar wedge bearing according to claim 1, is characterized in that: described blasting craft reaches SA3 grade.