CN101245653A - Anti-torsion steel-concrete combined beam without connector - Google Patents

Abstract

The invention relates to a torsion-resistant steel-concrete composite beam without connectors, belonging to the technical field of constructing beam components. The composite beam is mainly composed of wing plates and a steel beam under and supporting the wing plates; the wing plates consists essentially of concretes, intersecting steel longitudinal bars and steel stirrups that are enwrapped in the concretes and arranged at interval; the front ends and rear ends of the steel stirrups are closed; the steel beam with a rectangle-shaped cross section is composed of two lateral surfaces and a bottom surface; the lower edges of the two lateral surfaces are respectively and tightly connected with the two sides of the bottom surface, while the upper edges of the two lateral surfaces is fixedly connected with a support plate; the support plate is positioned in the wing plates and welded with the steel stirrups. The composite beam saves steels and realizes precise construction requirements for torsion-resistant composite beams, thus greatly reducing the production cost of the composite beams and improving the safety factors; in addition, the composite beam fills the gaps in the construction requirements of the steel and concrete composite beams.

Description

Anti-torsion steel-concrete combined beam without connector

Technical field

The present invention relates to a kind of steel-concrete composite beam that is widely used in traffic or building field, especially a kind of steel-concrete composite beam and structural parameters thereof that satisfy antitorque requirement are determined, belong to and build worker's beam technical field.

Background technology

In traffic bridge or the construction of building house beam,, adopt the compound beam that forms by two kinds of combinations of materials more and more, such as the compound beam of steel-concrete for the consideration of the performance separately that makes full use of different materials with the effect of performance whole synthesis.Existing steel-concrete composite beam is in compound stress in actual use often, and generally all has shearing resistance preferably and anti-bending strength.

According to the knowledge of the applicant, a kind of structure commonly used is in the existing steel-concrete composite beam: arrange that in concrete reinforcing bar forms wing plate, below wing plate, establish the frame type girder steel then, be connected by being embedded in steel connector in the wing plate (commonly used have peg) between wing plate and the girder steel.The applicant finds: the steel-concrete composite beam of this structure, need expend a large amount of steel connectors between its wing plate and the girder steel; And what form by the steel connector between wing plate and the girder steel is that the multiple spot that disperses at interval is connected, therefore easily causes deformation such as wing plate perk under being turned round, thereby influences the Total tune performance.

In addition, the torsional property of the existing steel-concrete composite beam of this structure is often undesirable.This is to have blindness because of the structure at this compound beam on torsional resistance design, is in gear shaper without theoretical foundation, state without ready patterns to follow substantially, and its structural parameters only depend on experience to estimate; Thereby cause or the situation of waste of material, or torsional property is not good, even because of the structural parameters mistake of estimating makes this compound beam not have enough torsional properties, thereby brings the potential safety hazard in the use.

Summary of the invention

The present invention wants the technical solution problem to be: at above-mentioned existing steel-concrete composite beam structure consumptive material big defective and the definite blindness of antitorque structural parameters, a kind of anti-torsion steel-concrete combined beam without connector is proposed, this compound beam not only can be saved great deal of steel, and should guarantee enough torsional properties, thereby thoroughly eliminate the hidden dangers in project that the steel-concrete composite beam under being turned round may have.

In order to solve above technical problem, anti-torsion steel-concrete combined beam without connector of the present invention mainly is made of wing plate and the girder steel that is supported on below the wing plate, described wing plate mainly by concrete, be contained within that the vertical muscle of spaced apart and cross-coupled in length and breadth steel and stirrup muscle constitute in the concrete, described stirrup muscle head and the tail are closed, described girder steel is made of two sides and bottom surface, the lower limb of described two sides is connected with the dual-side of described bottom surface respectively, and its top edge is fixed with supporting plate; Described supporting plate is positioned at wing plate and welds with the stirrup muscle.

The concrete analysis of above-mentioned anti-torsion steel-concrete combined beam without connector is as follows:

1) since moment of torsion two parts addition that moment of torsion that the antitorque supporting capacity of the steel-concrete composite beam that wing plate and girder steel form is born by wing plate and girder steel are born form, and the moment of torsion that wing plate and girder steel are born is only relevant with its cross section parameter, therefore compare the steel-concrete composite beam that connects by connector between existing wing plate and the girder steel, anti-torsion steel-concrete combined beam without connector of the present invention is after removing connector, the torsional property of compound beam can not be affected, specifically referring to aftermentioned embodiment.

2) compound beam of the present invention is when bearing moment of torsion, because the stirrup of wing plate directly is welded on the supporting plate of girder steel, make wing plate be connected by the multiple spot that forms by connector originally and become continuous proximal line connection (being equivalent to significantly increase wing plate counted with being connected of girder steel) with girder steel, therefore can be made better co-ordination between wing plate and the girder steel in the process turning round of compound beam, and produce to start when effectively suppressing wing plate and being turned round and wait deformation, thereby the Total tune and the stability of raising compound beam; And great advantage is: the compound beam that this type of compound beam can be avoided containing connector originally is when being turned round, and connector root surrounding concrete stress is concentrated and the drawback of the local failure that causes easily.This that is to say, remove connector after, on the impregnable basis of torsional property that keeps compound beam, Total tune and the stability of compound beam in antitorque process is promoted, and has overcome the drawback of the local destructible of concrete.We can say further, owing to improved Total tune and the stability of compound beam in being turned round process, make that under same antitorque cracking value and limiting value situation the deflection after being turned round of compound beam of the present invention is less than the existing deflection that contains the steel-concrete composite beam of connector; Be more suitable in engineering using the requirement of the normal functional performance that is content with very little more undoubtedly and turn round the little compound beam of back deflection.

What deserves to be mentioned is that above-mentioned 2 concrete analyses are not to expect easily for the person of ordinary skill of the art.At first, the structural parameters of existing steel-concrete composite beam are determined this just blindly, thus connector compound beam antitorque had or not influence also is ambiguous (determining to ask for an interview aftermentioned about structural parameters); Secondly, wing plate be connected after girder steel removes connector the compound beam deflection that brings reduce unexpected especially.

To sum up, anti-torsion steel-concrete combined beam without connector of the present invention is compared existing steel-concrete composite beam, owing to change the direct and stirrup welding with girder steel routinely, is keeping on the torsional property basis of invariable, save connector fully, thereby saved great deal of steel; Also improve Total tune and the stability of compound beam in antitorque process simultaneously, thereby not only good but also light can carry the compound beam of being turned round for building or field of traffic provide a kind of.

One of further requirement of above-mentioned anti-torsion steel-concrete combined beam without connector is that the ratio of the width of described wing plate and height satisfies following formula: $12\&GreaterEqual;\frac{b_c}{h_c}\&GreaterEqual;(\frac{T_{1c}}{W_t{f}_c}-0.154)/0.0176,$ In the formula: b _c-wing plate width, h _c-wing plate height, T _1c-wing plate cracking resistance moment of torsion, T _1c=α _K1α _K2W _tf _t, W _t-wing plate cross section plasticity resistance moment, f _cThe concrete crushing strength of-wing plate, α _K1The concrete tensile strength reduction coefficient of-wing plate, α _K1Get 0.7, α _K2The antitorque raising coefficient of-wing plate, ${\mathrm{\&alpha;}}_{\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">k</figure-callout>}2}=0.95+0.057\frac{b_c}{h_c},$ f _tThe concrete tensile strength of-wing plate;

The spacing of described stirrup satisfies following formula: ${\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">s</figure-callout>}}_1\&le;\min (\frac{b_{\mathrm{cor}}^{\&prime;\&prime;}+h_{\mathrm{cor}}^{\&prime;\&prime;}}{4},250)\mathrm{mm},$ In the formula: s ₁-stirrup spacing, ${\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">s</figure-callout>}}_1=\frac{{2A}_{\mathrm{svt}}\mathrm{\&phi;}{A}_0{f}_{\mathrm{yv}}\cot \mathrm{\&alpha;}}{T_{1c}},$ A _Svt-single stirrup sectional area, $A_{\mathrm{svt}}=\mathrm{\&pi;}{\left(\frac{{\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">d</figure-callout>}}_1}{2}\right)}^2,$ φ=0.85, A ₀-shear flow center line encloses the wing plate cross-sectional area, A ₀=(b _c-t) (h _c-t), f _Yv-stirrup yield strength value, α-wing plate principal compressive stress inclination angle, 30 °≤α≤45 °, b _Cor" width between the center line of the long limit of stirrup, $b_{\mathrm{cor}}^{\&prime;\&prime;}=b_c-2t_c-{\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">d</figure-callout>}}_1,$ h _Cor" width between the stirrup minor face center line, $h_{\mathrm{cor}}^{\&prime;\&prime;}=h_c-2t_c-{\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">d</figure-callout>}}_1,$ , d ₁The barocline effective thickness of bar of-stirrup diameter, t-wing plate is got t=h _c/ 3, t _c-wing plate protective layer thickness, 15mm≤t _c≤ 40mm;

The diameter of described vertical muscle satisfies following formula: $25\&GreaterEqual;{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">d</figure-callout>}}_2\&GreaterEqual;\frac{s_1\&CenterDot;\tan \mathrm{\&alpha;}}{16},$ In the formula: d ₂-vertical muscle diameter;

The spacing of described vertical muscle satisfies following formula:: 100mm≤s ₂≤ 300mm is in the formula: s ₂-longitudinal bar spacing.

One of concrete analysis that above-mentioned anti-torsion steel-concrete combined beam without connector further requires is as follows:

1) destruction of the steel-concrete composite beam under being turned round bar is crushed to be caused owing to concrete baroclines.Because concrete flange plate is thinner, concrete flange plate is subjected to the constraint of reinforcing bar, and (b is compared on the length limit than beam type member _c/ h _c＜6) stronger, show very big plasticity.For fear of the too early destruction of the concrete flange plate of compound beam, can bring into play the due effect of girder steel, need the smallest cross-sectional size of regulation compound beam concrete flange plate, promptly stipulate the restrictive condition in concrete flange plate cross section.At present at home, one, the cross section restriction condition of beam type member is expressed with the theory of plasticity, i.e. T _u=ω W _tf _c, in the formula, T _uBe beam type unit construction beam limit torsional strength, ω is that the wing plate cross section does not reach perfectly plastic coefficient; Two, plate-type component is got $\mathrm{\&omega;}=0.154+0.0176\frac{b_c}{h_c};$ Therefore, the restrictive condition in the wing plate cross section of board-like compound beam is $\frac{b_c}{h_c}\&GreaterEqual;(\frac{T_{1c}}{W_t{f}_c}-0.154)/0.0176.$ Because shear strain influences the distribution of flexural stress, have the shear lag phenomenon in the wing plate again, promptly longitudinal stress is along wing plate width skewness, and stress is big near the wing plate girder steel, and stress at a distance is little.Experimental study shows $\frac{b_c}{h_c}\&le;12$ The time wing plate performance can access good performance.

2) because the approximate stress distribution of plastic material that adopts of cracking torque is calculated, so the tensile strength of plate-type component concrete flange plate will suitably reduce, α is got in unification _K1=0.7, under situation with the antitorque plasticity resistance moment in identical cross section, the cracking strength of plate-type component concrete flange plate will be higher than the beam type member, this be since plate-type component under the reinforcing bar restrictive condition of girder steel and concrete flange plate, the constraint that the core concrete of concrete flange plate is subjected to shows very big plasticity than strong of beam type member more.α _K2Value can reflect the influence of the aspect ratio of concrete slab, can be through returning α _K2Be expressed as ${\mathrm{\&alpha;}}_{\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">k</figure-callout>}2}=0.95+0.057\frac{b_c}{h_c}.$ The cracking resistance moment of torsion of the steel-concrete composite beam under therefore being turned round can be expressed as T _1c=α _K1α _K2W _tf _t

3) stirrup spacing is the principal element of the steel-concrete composite beam torsional strength under influence is turned round, but stirrup spacing competence exertion effect within the specific limits.The spacing of stirrup also is one of restriction compound beam diagonal crack key factor of carrying out.Show that by test and numerical computations concerning the steel-concrete composite beam under being turned round, too small stirrup spacing is not only uneconomical but also inoperative; For excessive stirrup spacing, when diagonal crack appearance in a single day, crack width is just bigger.Test shows, can limit the diagonal crack widths of steel-concrete composite beam under the service condition when spacing of stirrup satisfies the following relationship formula:

$\left(1\right)---{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">s</figure-callout>}}_1=\frac{2A_{\mathrm{svt}}\mathrm{\&phi;}{A}_0{f}_{\mathrm{yv}}\cot \mathrm{\&alpha;}}{T},$ $\left(2\right)---{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">s</figure-callout>}}_1\&le;\min (\frac{b_{\mathrm{cor}}^{\&prime;\&prime;}+h_{\mathrm{cor}}^{\&prime;\&prime;}}{4},250)\mathrm{mm}.$

4) under torsional interaction, vertical muscle mainly bears pulling force and pin power, the extrapolability that the vertical muscle in bight also bears diagonal compression and produced.The vertical muscle in bight plays the anchor slab effect of stirrup.The vertical muscle diameter in bight is too small when the spacing of stirrup is excessive, and when longitudinal bar spacing was very big, the bight diagonal compression will be released concrete.The excessive relatively waste of vertical muscle diameter.Longitudinal bar spacing is between 100mm to 300mm the time, and crack width is less.Above-mentioned destruction can be avoided when the relational expression below the diameter of the vertical muscle in bight and spacing satisfy:

$\left(1\right)---25\&GreaterEqual;{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">d</figure-callout>}}_2\&GreaterEqual;\frac{s_1\&CenterDot;\tan \mathrm{\&alpha;}}{16},$ (2)100mm≤s ₂≤300mm。

Two of the further requirement of above-mentioned anti-torsion steel-concrete combined beam without connector is: the two ends of described stirrup curve 135 °, and its two ends portion of bending encases vertical muscle, and its two ends are bent minister's degree and satisfied following formula: l=6d ₁, in the formula: minister's degree is bent in the two ends of l-stirrup.

The further concrete analysis of above-mentioned anti-torsion steel-concrete combined beam without connector two as follows: in the steel-concrete composite beam under being turned round, stirrup mainly plays and vertically sockets effect, the extrapolability that is produced with balance concrete diagonal compression.Test shows: when stirrup satisfied lap length, the torsional strength of beam increased significantly.Draw back phenomenon in the stirrup joint when the too short beam of stirrup overlap joint destroys, enough anchorage lengths are arranged so should note stirrup.The free-ended anchoring of stirrup should bend in the interior concrete of the inboard scope of stirrup.The pure compound beam wing plate of turning round often diagonal crack all occurs on four sides, so that stirrup must make is closed, so that resist the extrapolability in bight, four sides.Antitorque test both domestic and external shows: when the two ends of stirrup curve 135 °, extend 6d again ₁, and making crotch encase vertical muscle, this form all can satisfy the requirement of antitorque structure.

Three of the further requirement of above-mentioned anti-torsion steel-concrete combined beam without connector is: as described wing plate width b _cDuring≤400mm, described vertical muscle is arranged in four jiaos of stirrup; As described wing plate width b _cDuring 〉=400mm, described vertical muscle is peripheral uniform along stirrup; Described vertical muscle maximum configured radical satisfies following formula: $n_{\max }=\frac{A_{\mathrm{svt}}}{\mathrm{\&pi;}{\left(\frac{{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">d</figure-callout>}}_2}{2}\right)}^2{s}_1}{u}_{\mathrm{cor}}\left(\frac{f_{\mathrm{yv}}}{f_{\mathrm{sy}}}\right){\mathrm{<figure-callout\; id="2"\; label="cot"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">cot</figure-callout>}}^2\mathrm{\&alpha;},$ In the formula: n _Max-vertical muscle maximum configured radical, u _CorThe interior girth of-stirrup, u _Cor=2 (b _Cor+ h _Cor), b _CorWidth between the inboard, the long limit of-stirrup, h _CorWidth between the-stirrup minor face inboard, f _Sy-vertical muscle yield strength value.

The further concrete analysis of above-mentioned anti-torsion steel-concrete combined beam without connector three as follows: in the steel-concrete composite beam under being turned round, vertical muscle mainly makes compound beam play a part vertically to socket, and for this reason, should there be suitable anchorage length vertical muscle end.For the pure compound beam of turning round, the width b in wing plate cross section _cDuring less than 400mm, vertical muscle can centralized configuration four jiaos of stirrups; Width b _cDuring greater than 400mm, vertical muscle can evenly be arranged along the periphery of stirrup.Press longitudinal bar spacing and arrange when indulging muscle, need the maximum quantity of reinforcement n of control _Max

Four of the further requirement of above-mentioned anti-torsion steel-concrete combined beam without connector is: described wing plate principal compressive stress inclination alpha=37.5 °.

The further concrete analysis of above-mentioned anti-torsion steel-concrete combined beam without connector four as follows: in the steel-concrete composite beam under being turned round, the inclination alpha of concrete principal compressive stress is not only relevant with the size of vertical muscle stretching strain, stirrup stretching strain, concrete main compressive strain, also with act on compound beam on the moment of torsion and the ratio of moment of flexure relevant, along with the minimizing of twist and warping ratio, α will increase.α generally is limited in 30 °≤α≤45 °, so that the carrying out of control crack.Experiment shows, as α during greater than above-mentioned scope, it is very fast that the width in crack increases, for the frame type girder steel, because the effect of contraction of girder steel is got α=37.5 °

To sum up, anti-torsion steel-concrete combined beam without connector of the present invention is compared existing steel-concrete composite beam, on the basis that guarantees enough torsional properties, steel had both been saved, Total tune and stability in antitorque have been improved again, but also obtained accurate antitorque structure requirement, thereby reduce the manufacturing cost of compound beam greatly and improve safety factor (should thoroughly eliminate hidden dangers in project).

Description of drawings

Fig. 1 is the cross-sectional structure schematic diagram of embodiment of the invention anti-torsion steel-concrete combined beam without connector.

Fig. 2 be among Fig. 1 A-A to generalized section.

Fig. 3 is the cross-sectional structure schematic diagram of wing plate among Fig. 1.

Fig. 4 is as a comparison the cross-sectional structure schematic diagram that contains the connector steel-concrete composite beam in the embodiment of the invention.

The specific embodiment

Embodiment one

The anti-torsion steel-concrete combined beam without connector of present embodiment such as Fig. 1, Fig. 2 and shown in Figure 3 mainly are made of rectangular wing plate 1 of cross section and the girder steel 2 that is supported on below the wing plate 1.Wing plate 1 mainly by concrete, be contained within that the spaced apart and vertical muscle 5 of steel handing-over in length and breadth and stirrup muscle 6 constitute in the concrete, stirrup muscle 6 head and the tail are closed.Girder steel 2 is made of two sides 3 and bottom surface 4 and forms rectangular cross section; The lower limb of two sides 3 respectively with the welding of the dual-side of bottom surface 4, its top edge is welded with supporting plate 7, supporting plate 7 be embedded in the wing plate and with closed stirrup muscle 6 welding.Closed stirrup muscle 6 is rectangular.

The parameter of this compound beam is determined as follows:

1) span of compound beam is 3m, and height overall h is 270mm (as shown in Figure 1), girder steel 2 high h _sBe 200mm, rise-span ratio is 1/11.1.

For the main supporting frame in the building structure, the rise-span ratio that generally can get the freely-supported compound beam is 1/10～1/20, and the rise-span ratio of continuous composite beam is 1/20～1/25, and promptly the rise-span ratio of compound beam should be between the 1/10-1/25; For the beam of non-bearing framework, depth of section also can further suitably reduce; Some in particular cases, the shear resistance of girder steel 2 relative deficiency that seems, for fear of this situation, the overall height h in compound beam cross section should not surpass girder steel 2 depth of section h _S2.5 times.

2) wing plate 1 stretches out girder steel 2 center line 229mm, and wing plate 1 stretches out girder steel 2 edge 199mm.In the general building structure, wing plate 1 should satisfy and stretches out girder steel 2 center lines and be not less than 150mm, stretches out the structure requirement that girder steel 2 edges are not less than 50mm.

3) wing plate 1 protective layer thickness t _cBe 20mm, wing plate 1 width b _cBe 700mm, wing plate 1 height h _cBe 80mm, stirrup 6 yield strength f _Yv=vertical muscle 5 yield strength f _Sy=285.5MPa (measured value), the concrete tensile strength f of wing plate 1 _t=2.73MPa (measured value), the concrete crushing strength f of wing plate 1 _c=23.45MPa (measured value).

4) in the general building structure, wing plate 1 cross section is turned round the plasticity resistance moment and is calculated as follows: $W_t=\frac{{{\mathrm{<figure-callout\; id="2"\; label="h\; c"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">h</figure-callout>}}_c}^2}{6}({3b}_c-h_c)=\frac{{0.08}^2}{6}(3\&times;0.7-0.08)\&ap;0.002155,$ The cracking resistance moment of torsion of wing plate 1 then

$T_{1c}={\mathrm{\&alpha;}}_{\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">k</figure-callout>}1}{\mathrm{\&alpha;}}_{k2}{W}_t{f}_t=0.7\&times;(0.95+0.057\&times;\frac{0.7}{0.08})\&times;0.002155\&times;2.73\&times;{10}^3=5.97\mathrm{kN}.m,$

Then $(\frac{T_{1c}}{w_t{f}_c}-0.154)/0.0176=(\frac{5.97\&times;{10}^3}{0.002155\&times;23.45\&times;{10}^6}-0.154)/0.0176\&ap;-2.077$

$\frac{b_c}{h_c}=\frac{700}{80}=8.75,$ 8.75＞-2.077, satisfy $12\&GreaterEqual;\frac{b_c}{h_c}\&GreaterEqual;(\frac{T_{1c}}{W_t{f}_c}-0.154)/0.0176;$

5) diameter of stirrup 6 is chosen by requirements of common buildings structure, and the plain bar of present embodiment selection φ 6mm is made stirrup 6, and wing plate 1 principal compressive stress inclination alpha is got 37.5 °, the wing plate 1 bar effective thickness t=h that baroclines _c/ 3=80/3=26.7mm, wing plate 1 protection thickness t _cGet 20mm, the cross-sectional area A of shear flow wing plate that center line encloses 1 ₀=(700-26.7) (80-26.7)=35911mm ², the list of stirrup 6 props up sectional area A _St=3.14 * 3 ², stirrup 6 spacings then

${\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">s</figure-callout>}}_1=\frac{2\&times;3.14\&times;3^2\&times;0.85\&times;285.5\&times;1.3\&times;35911}{5.97\&times;{10}^6}=107\mathrm{mm},$ Get s ₁=100mm, b _Cor"=700-2 * 20-6=654mm, h _Cor"=80-2 * 20-6=34mm, $\frac{b_{\mathrm{cor}}^{\&prime;\&prime;}+h_{\mathrm{cor}}^{\&prime;\&prime;}}{4}=\frac{654+34}{4}=172\mathrm{mm},$ Stirrup 6 distance s ₁=100mm≤min (172,250) mm meets the demands;

6) diameter d is selected in examination earlier ₂Be the vertical muscle 5 of plain bar conduct of 6mm, then

6mm＞4.8mm is through checking vertical muscle 5 diameter d ₂Satisfy $25\&GreaterEqual;{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">d</figure-callout>}}_2\&GreaterEqual;\frac{s_1\tan \mathrm{\&alpha;}}{16}$ Requirement;

7) two ends of stirrup 6 curve 135 °, and the two ends of stirrup 6 portion of bending encases vertical muscle, and the l=6 * 6=36mm of minister's degree is bent in these two ends;

8) b _Cor=700-2 * 20-2 * 6=648mm, h _Cor=80-2 * 20-2 * 6=28mm, u _Cor=2 (b _Cor+ h _Cor)=2 * (648+28)=1352mm, the maximum configured radical of vertical muscle 5

$n_{\max }=\frac{3.14\&times;9}{3.14\&times;9\&times;100}\&times;1352\&times;\left(\frac{285.5}{285.5}\right)\&times;{1.3}^2=22.8,$

Get n _Max=23, the spacing of vertical muscle 5 is got s ₂=125mm evenly arranges the six roots of sensation up and down, satisfies 100mm≤s ₂The requirement of≤300mm.Vertical muscle 5 is evenly arranged along the periphery of stirrup 6.

The steel-concrete composite beam of the compound beam of above-mentioned present embodiment and strap bolt nail (be wing plate 1 be connected by peg with girder steel 2 steel-concrete composite beam) is carried out relatively being calculated as follows of twisting resistance:

1. the steel-concrete composite beam of selecting strap bolt nail for use as shown in Figure 4, the structure of this compound beam and present embodiment compound beam are basic identical, pre-buried spaced apart and the peg 8 that exposes the termination in different is in wing plate 1 middle part, the supporting plate 7 of the exposed junction of peg 8 and girder steel 2 welds.Its structural parameters are identical with the present embodiment compound beam.

2. compound beam cracking torque design formulas is: T _Cr=α _K1α _K2W _tf _t+ 2hbh _cf _t

Wherein: α ₁=0.7, ${\mathrm{\&alpha;}}_{\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">k</figure-callout>}2}=0.95+0.057\frac{b_c}{h_c}$

$W_t=\frac{{{\mathrm{<figure-callout\; id="2"\; label="h\; c"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">h</figure-callout>}}_c}^2}{6}(3b_c-h_c)=\frac{{0.08}^2}{6}(3\&times;0.7-0.08)\&ap;0.002155$

2.1 the cracking torque of present embodiment compound beam

$T_{\mathrm{cr}}=0.7\&times;(0.95+0.057\&times;\frac{0.7}{0.08})\&times;0.002155\&times;2.73\&times;{10}^3$

$+2\&times;0.27\&times;0.25\&times;0.08\&times;2.73\&times;{10}^3=35.45\mathrm{kN}.m$

2.2 the cracking torque of the steel-concrete composite beam of strap bolt nail

$T_{\mathrm{cr}}=0.7\&times;(0.95+0.057\&times;\frac{0.7}{0.08})\&times;0.002155\&times;2.73\&times;{10}^3$

$+2\&times;0.27\&times;0.25\&times;0.08\&times;2.73\&times;{10}^3=35.45\mathrm{kN}$

3. compound beam ultimate torque design formulas is: $T_u=A_0\mathrm{tk}{\mathrm{<figure-callout\; id="2"\; label="f\; c\; sin"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">f</figure-callout>}}_c\sin 2\mathrm{\&alpha;}(1+\frac{\mathrm{GJ}}{K_{t0}^{\&prime;\&prime;}})$

Wherein: f _c=23.45MPa, $t=\frac{{\mathrm{<figure-callout\; id="3"\; label="h\; c"\; filenames="S2008100198426E00011.png,S2008100198426E00012.png"\; state="\{\{state\}\}">h</figure-callout>}}_c}{3}=26.7\mathrm{mm},$

A ₀＝(700-26.7)(80-26.7)＝35911mm ²，k＝1.15，G＝7.9×10 ⁴MPa，

J＝4.19×10 ⁵mm ⁴，α＝37.5°，k _t0″＝4.13×10 ¹⁰N.mm ²

3.1 the ultimate torque of present embodiment compound beam

3.2 the ultimate torque of the steel-concrete composite beam of strap bolt nail

Contrast the cracking torque and the ultimate torque of above-mentioned two kinds of compound beams, because the cracking torque of two kinds of compound beams is identical with the ultimate torque design formulas, and each parameter is not subjected to the influence of peg in the design formulas, therefore, the cracking torque and the ultimate torque numerical value of two kinds of compound beams drawing of Practical Calculation are identical.This shows that the compound beam of present embodiment has been saved a large amount of pegs on the basis that guarantees antitorque supporting capacity.

In addition, in the present embodiment, the stirrup 6 in the wing plate 1 directly welds with the supporting plate 7 of girder steel 2, because stirrup 6 is circumferential arrangement in wing plate 1, therefore for wing plate 1 and girder steel 2, what it formed each other is that continuous proximal line connects rather than disperse independently connection.Like this, the connection integrity between wing plate 1 and the girder steel 2 can be better.Therefore the compound beam integral body of present embodiment is when bearing moment of torsion, wing plate 1 and better co-ordination of girder steel 2, be the Total tune and the good stability of the compound beam of present embodiment, thereby in being turned round process, can effectively suppress the distortion of wing plates 1 such as starting of wing plate 1 or girder steel 2.

Further be, the steel-concrete composite beam of present embodiment has provided the structural parameters requirement of clear and definite, changes the blindness of the antitorque structural requirement of steel-concrete composite beam in the past, thereby can avoid waste of material or potential safety hazard.

In addition to the implementation, the present invention can also have other embodiments.Such as easy understanding, 1) wing plate 1 cross section also can be trapezoidal, other quadrangle or polygon; 2) two sides 3 of girder steel 2 also can be to form with bottom surface 4 whole bendings; 3) supporting plate 7 of the top edge of girder steel 2 also can be to make integral body with the top edge of girder steel 2; 4) cross section of girder steel 2 also can be trapezoidal or other quadrangle; 5) closed stirrup muscle 6 also can form prismatic, hexagon, other polygon or shapes such as circle, ellipse; Or the like.All employings are equal to the technical scheme of replacement or equivalent transformation formation, all drop on the protection domain of requirement of the present invention.

Claims (8)

1. anti-torsion steel-concrete combined beam without connector, mainly constitute by wing plate and the girder steel that is supported on below the wing plate, described wing plate mainly by concrete, be contained within that the vertical muscle of spaced apart and cross-coupled in length and breadth steel and stirrup muscle constitute in the concrete, described stirrup muscle head and the tail are closed, and described girder steel is made of two sides and bottom surface; It is characterized in that: the lower limb of described two sides is connected with the dual-side of described bottom surface respectively, and its top edge is fixed with supporting plate; Described supporting plate is positioned at wing plate and welds with the stirrup muscle.

2. according to the described anti-torsion steel-concrete combined beam without connector of claim 1, it is characterized in that: 1) ratio of the width of described wing plate and height satisfies following formula:

$12\&GreaterEqual;\frac{b_c}{h_c}\&GreaterEqual;(\frac{T_{1c}}{W_t{f}_c}-0.154)/0.0176,$ In the formula: b _c-wing plate width, h _c-wing plate height, T _1c-wing plate cracking resistance moment of torsion, T _1c=α _K1α _K2W _tf _t, W _t-wing plate cross section plasticity resistance moment, f _cThe concrete crushing strength of-wing plate, α _K1The concrete tensile strength reduction coefficient of-wing plate, α _K1Get 0.7, α _K2The antitorque raising coefficient of-wing plate, ${\mathrm{\&alpha;}}_{k2}=0.95+0.057\frac{b_c}{h_c},$ f _tThe concrete tensile strength of-wing plate;

2) spacing of described stirrup satisfies following formula: $s_1\&le;\min (\frac{b_{\mathrm{cor}}^{\&prime;\&prime;}+h_{\mathrm{cor}}^{\&prime;\&prime;}}{4},250)\mathrm{mm},$ In the formula: s ₁-stirrup spacing, $s_1=\frac{{2A}_{\mathrm{svt}}\mathrm{\&phi;}{A}_0{f}_{\mathrm{yv}}\cot \mathrm{\&alpha;}}{T_{1c}},$ A _Svt-single stirrup sectional area, $A_{\mathrm{svt}}=\mathrm{\&pi;}{\left(\frac{d_1}{2}\right)}^2,$ φ=0.85, A ₀-shear flow center line encloses the wing plate cross-sectional area, A ₀=(b _c-t) (h _c-t), f _Yv-stirrup yield strength value, α-wing plate principal compressive stress inclination angle, 30 °≤α≤45 °, b _Cor" width between the center line of the long limit of stirrup, b _Cor"=b _c-2t _c-d ₁, h _Cor" width between the stirrup minor face center line, h _Cor"=h _c-2t _c-d ₁, d ₁The barocline effective thickness of bar of-stirrup diameter, t-wing plate is got t=h _c/ 3, t _c-wing plate protective layer thickness, 15mm≤t _c≤ 40mm;

3) diameter of described vertical muscle satisfies following formula: $25\&GreaterEqual;d_2\&GreaterEqual;\frac{s_1\&CenterDot;\tan }{16},$ In the formula: d ₂-vertical muscle diameter;

4) spacing of described vertical muscle satisfies following formula: 100mm≤s ₂≤ 300mm is in the formula: s ₂-longitudinal bar spacing.

3. according to the described anti-torsion steel-concrete combined beam without connector of claim 2, it is characterized in that: the two ends of described stirrup curve 135 °, and its two ends portion of bending encases described vertical muscle, and its two ends are bent minister's degree and satisfied following formula: l=6d ₁, in the formula: minister's degree is bent in the two ends of l-stirrup.

4. according to the described anti-torsion steel-concrete combined beam without connector of claim 3, it is characterized in that: when described wing plate width during smaller or equal to 400mm, described vertical muscle is arranged in four jiaos of stirrup; When described wing plate width during greater than 400mm, described vertical muscle is peripheral uniform along stirrup; Described vertical muscle maximum configured radical satisfies following formula: $n_{\max }=\frac{A_{\mathrm{svt}}}{\mathrm{\&pi;}{\left(\frac{d_2}{2}\right)}^2{s}_1}{u}_{\mathrm{cor}}\left(\frac{f_{\mathrm{yv}}}{f_{\mathrm{sy}}}\right){\cot }^2\mathrm{\&alpha;},$ In the formula: n _Max-vertical muscle maximum configured radical, u _CorThe interior girth of-stirrup, u _Cor=2 (b _Cor+ h _Cor), b _CorWidth between the inboard, the long limit of-stirrup, h _CorWidth between the-stirrup minor face inboard, f _Sy-vertical muscle yield strength value.

5. according to the described anti-torsion steel-concrete combined beam without connector of claim 4, it is characterized in that: described wing plate principal compressive stress inclination angle is 37.5 °.

6. according to the described anti-torsion steel-concrete combined beam without connector of claim 5, it is characterized in that: described wing plate cross section plasticity resistance moment $W_t=\frac{{h_c}^2}{6}({3b}_c-h_c).$

7. according to the described anti-torsion steel-concrete combined beam without connector of claim 6, it is characterized in that: described wing plate cross section is rectangular, and described girder steel cross section is rectangular, and described stirrup muscle is rectangular.

8. according to the described anti-torsion steel-concrete combined beam without connector of claim 7, it is characterized in that: the rise-span ratio of described compound beam is 1/10-1/25, and its overall depth of section is smaller or equal to 2.5 times of the girder steel depth of section; Described wing plate stretches out the distance of girder steel center line more than or equal to 150mm, and its distance of stretching out the girder steel edge is more than or equal to 50mm.

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