CN87102320A - The application of initial stress technique of steel pipe concrete structures - Google Patents

Abstract

The invention belongs to initial stress technique of steel pipe concrete structures.

Prior art adopts the reinforcement theory of core concrete later stage.The technical program belongs to initial stress technique, adopts core concrete reinforcement theory in early stage; Core concrete adopts high-grade concrete, steel fibrous concrete, or arrangement of reinforcement concrete filled steel tube scheme, and has proposed working curve family scope on this basis.

This programme is applicable to the recovery technique of framework, post, bridge pier, stake, water conservancy project structure, trussed construction and pillar etc.The technical program can be guaranteed to improve supporting capacity more than 40～100%.

Description

The invention belongs to initial stress technique of steel pipe concrete structures.

The technical characterictic of existing concrete filled steel tube is to recognize that the later stage reinforcement theory of VOnMiSes yield condition and core concrete; Axial compression stress in the steel pipe is б a-1≤0.5fy smaller or equal to 50 percent of yield strength; Core concrete is 200～No. 400.It is described to see building structure journal the 1st the 1st phase of volume, the 3rd the 1st phase of volume, the 5th the 6th phase of volume for details; Also only be applied to 0.7R=1900Kgf/cm in the CN85104444A manual ²The axial compression stress that is steel pipe only reaches 1520Kgf/cm ²; No. 460, core concrete.

The objective of the invention is to and to be applied to encased structures such as post, framework, truss, to support, give the repairing and reinforcement technology of stress rod member, stake and pillar with new technical scheme from the viewpoint of stress, rule.In the hope of saving steel to greatest extent, the latent effectiveness of performance structure.

The invention is characterized in:

1. proved that steel pipe has the drag of self-stress effect (load effect) steel pipe at hoop

$6R={\mathrm{\Σ}}_{\mathrm{Vax}>0}^{\mathrm{Vac}\≤1.0}\mathrm{VacE\Δ\ϵa}-1+\sqrt{{\mathrm{fy}}^2-6_1^2-6_1{6}_2}$

2. core concrete has self-stress effect, and core concrete belongs to strengthens the carrying mode of operation of later stage decay, best strain ν ac=0.3～0.5 early stage; Modulus of elasticity coefficient of intensification Sc=1.05～1.5 of ν ac＜0.5 o'clock.

3. encased structures has self-stress effect, belongs to typically from stress structure.

4. the stress development of core concrete, the raising of lateral deformation and label thereof has machining function to the stress development of steel pipe.Improve the core concrete label or adopt steel fibrous concrete can control the lateral deformation of core concrete effectively, improve the axial carrying capacity of concrete filled steel tube rod member, and obtain the economic effect of saving steel.

5. self-stress effect hypothesis, dynamic balance field, main force's field hypothesis have confirmed that core concrete and steel pipe o'clock strictly observe deformation compatibility condition ε ' in ν ac≤1.0 _A-1=ε ' _C-1; Steel pipe is obeyed generalized Hooke's law at stress one strain stress relation of axial and hoop.

6. improve the core concrete label or adopt steel fibrous concrete (in the best condition) can reach yield stress f y in the axial compression stress of ν ac≤0.5 o'clock steel pipe; And its circumference stress still is in the low value stage, б a-2＜0.5fy.

7. according to above characteristics, corresponding to the label 45MPa＜Rc＜99MPa of its core concrete of 1 grade of steel steel pipe (μ=0.04～0.16); Label corresponding to its core concrete of 16 manganese steel pipes (μ=0.04～0.12) is 45MPa＜Rc＜150MPa.

8. when core concrete is steel fibrous concrete, be 20MPa＜Rac＜75MPa corresponding to 1 grade of its label of steel steel pipe; Corresponding to 16 its labels of manganese steel pipe is 20MPa＜Rac＜118MPa.

9. for large eccentricity or small pieces eccentric bar, at the major control in-plane, can dispose in the inboard of steel pipe and to give stress and non-its core concrete of stress reinforcing bar (detailed accompanying drawing: (1) steel pipe, (2) fill plate, (3) arrangement of reinforcement, (4) welding are boxed out, (5) welding hole cover plate) that gives can bear the compressive stress of giving less than 0.7R28.

10. proposed to have more family of curves's scope of high bearing capacity, its cuff is φ=0.12～0.85(1 level steel steel pipe than index), φ=0.10～1.05(16 manganese steel pipe); And best cuff is than indication range φ=0.13～0.29(1 level steel steel pipe); φ=0.12～0.29(16 manganese steel pipe).(annotate: the core concrete label is taken by feature 7.8) contrasts with the measured data of this programme method and nearly 100 groups of test specimens, all is better than existing technical scheme.

Good effect of the present invention is:

1. can improve supporting capacity 5%～150%, can guarantee under the optimum state to improve supporting capacity more than 40%.

2. steel can be saved in a large number and steel can be saved more than 25% than existing technology.

3. the technical program can be applicable to post, framework, truss, gives and make or now make stake, bridge pier, port, Haihe River harbour post, pile foundation and give the stress tension member, the repairing and reinforcement technology of a kind of support of non-telescoping formula and pillar.

Claims (10)

1, the prior art of encased structures is admitted the later stage reinforcement theory of VonMises yield condition and core concrete; Axial compression stress in the steel pipe less than, equal 50 percent of yield stress, i.e. σ a-1≤0.5fy; Core concrete is 200～No. 400.The invention is characterized in: proved that 1. steel pipe and core concrete have self-stress effect, belonged to from stress structure; 2. core concrete belongs to the carrying mode of operation that strengthen early stage, the later stage decays; 3. the raising of the development of the stress development of core concrete, lateral deformation and label has machining function to the stress development of steel pipe; 4. steel pipe and core concrete o'clock strictly observe deformation compatibility condition ε ' a-1=ε ' c-1 in ν ac≤1.0; 5. steel pipe is obeyed generalized Hooke's law at the stress-strain relationship of axial and hoop; 6. proposed to have more family of curves's scope of high bearing capacity, its cuff is than index Φ=0.12～0.85 (1 grade of steel steel pipe); Φ=0.10～1.05 (16 manganese steel pipe), and the scope Φ of best curve family=0.13～0.29 (1 grade of steel steel pipe); Φ=0.12～0.29 (16 manganese steel pipe); 7. can pour into high-grade concrete in the steel pipe; High-grade cement mortar; And steel fibrous concrete.8. can need configuration to give stress and the non-stress reinforcing bar that gives by design in the concrete filled steel tube rod member.

The technical program can improve concrete filled steel tube rod member compressive capacity 5～150% (containing 1 grade of steel steel pipe and 16 manganese steel pipes).

The technical program can be applicable to axial compression rod member, small eccentricity and the large eccentric pressuring rod member of various different structures, with tension member and give the stress rod member.The present invention provides feasible technical scheme, and has obtained the economic effect that reduces bar cross section, alleviate dead load, save steel for the supporting capacity that improves existing encased structures.As a kind of three-dimensional frame construction: civilian and public framed building more than 20 layers and the industrial premises frame construction more than five layers.The pillar that it is characterized in that each layer framework all adopts the concrete filled steel tube rod member, level to girder and secondary beam, can adopt girder steel or reinforced concrete beam.Whole framework can all be a superstructure, and it is underground or all be underground frame construction also to can be partly top.Steel tube concrete frame puncheon also can be poured into a mould a layer concrete in its outside again by building requirements, so that it is the desired section of design.

2, require as described in 1 as claim: the three-dimensional frame construction of a kind of individual layer and multilayer.The frame column that it is characterized by each layer all adopts the concrete filled steel tube rod member.

3, require as described in 1 as claim: a kind of structure that contains microscler load-supporting part, if any post, skeleton etc.; The vertical load-supporting part of its post and skeleton all adopts the concrete filled steel tube rod member.

4, require as described in 1 as claim: a kind of support of on-telescopic or pillar, its pressure-containing parts are the concrete filled steel tube rod member.

5, require as described in 1 as claim: a kind of essence has adopted claim to require scheme as described in 1 and the frame construction that constitutes, as the assembling frame construction.

6, require as described in 1 a kind of repairing and reinforcement technology of reinforced concrete column as claim; It is characterized by in the pillar that needs reinforcement (garden shape, square, rectangle, polygon) peripheral solder and be processed into a steel pipe, beam is weldering reinforcing ring and rest down, then concrete perfusion or high-grade cement mortar again in the gap of steel pipe and pillar.

7, require as described in 1 a kind of application of concrete filled steel tube pile foundation as claim: the bottom that it is characterized in that stake has one to be cone shape steel boots, and is connected with the steel pipe of its top.The top of stake has reinforcing ring, and binds with steel deck-plate and to weld.Construction stage is driven underground this hollow steel pile tube to design elevation earlier.And then cut stake by designing requirement, and put into the cushion cap connecting reinforcement, concrete perfusion is promptly finished the making of steel pipe pile again, also can be made into concrete filled steel tube and gives the system stake.

8, require as described in 1 a seed stress concrete filled steel tube rod member as claim; Its feature a is that the inside center position of steel pipe is provided with the fine steel tube that a diameter is a bit larger tham the stretching rope diameter.The some millimeters of main steel pipe all are longer than at its two ends; There is circular steel cover plate for sealing one end of a circular hole at the center, and some stiffeners of welding between cover plate and the outstanding fine steel tube then are down concavity so that lay packing ring and the ground tackle of cable wire in the middle of it.The other end is earlier done Y shape with round steel and is connected, with fixed center steel pipe position, treat that this operation is finished after, just can be to pouring concrete within steel pipe, this end has also that centre is porose to have a steel deck-plate that stiffener, centre are time concavity.A branch of cable wire for stretch-draw is arranged in the middle of it.Its feature b is that the fine steel tube that passes cable wire is arranged on the inwall of steel pipe, and they are positioned at the two ends that two (or some) intersect diameter.Fine steel tube is longer than the some millimeters in main steel pipe two ends, cable wire portals and is located on the steel deck-plate between adjacent two stiffeners, and concrete placing in the steel pipe, the other end also have one of identical steel deck-plate, the stretch-draw cable wire is located in the fine steel tube of steel pipe walls inboard, and the stretching rope ground tackle is located between adjacent two stiffeners.

9, a kind of employing in essence as claim requires scheme as described in 1 and the underwater works that is combined into, as support under water, container, water conservancy project structure etc.

10, according to claim 1: a kind of concrete pier of steel tube, can be applicable to highway and railroad bridge, and People's Bank of China's overhead pedestrian crossing.

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