CN109112946B - Construction method of steel truss-corrugated steel web large-span combined beam bridge - Google Patents
Construction method of steel truss-corrugated steel web large-span combined beam bridge Download PDFInfo
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- CN109112946B CN109112946B CN201810635204.0A CN201810635204A CN109112946B CN 109112946 B CN109112946 B CN 109112946B CN 201810635204 A CN201810635204 A CN 201810635204A CN 109112946 B CN109112946 B CN 109112946B
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 234
- 239000010959 steel Substances 0.000 title claims abstract description 234
- 238000010276 construction Methods 0.000 title claims abstract description 16
- 230000006835 compression Effects 0.000 claims description 19
- 238000007906 compression Methods 0.000 claims description 19
- 238000010008 shearing Methods 0.000 claims description 11
- 239000002131 composite material Substances 0.000 claims description 8
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- 238000007596 consolidation process Methods 0.000 claims description 3
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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
- E01D12/00—Bridges characterised by a combination of structures not covered as a whole by a single one of groups E01D2/00 - E01D11/00
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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
- E01D19/00—Structural or constructional details of bridges
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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
- E01D21/00—Methods or apparatus specially adapted for erecting or assembling bridges
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Abstract
The invention discloses a steel truss-corrugated steel web large-span combined beam bridge, wherein a steel truss-corrugated steel web beam section is arranged outside a fulcrum lining concrete section in the bridge. The steel truss-corrugated steel web beam section can effectively share the shear load of the beam section, prevent the corrugated steel web from buckling and buckling instability to cause structural damage, meet the design requirement of a large-span corrugated steel web bridge and solve the problem that the corrugated steel web of the outer side beam section of the lining of the large-span corrugated steel web bridge is too large to be sheared. Accordingly, the inventor also establishes a corresponding construction method. The invention is suitable for designing and using the bridge with span of 160m or more, and has certain engineering significance and great economic value.
Description
Technical Field
The invention belongs to the field of transportation bridge and culvert engineering, and particularly relates to a steel truss-corrugated steel web large-span combined beam bridge and a construction method thereof.
Background
Along with the increase of the span of the bridge, the height of the section steel web near the fulcrum of the corrugated steel web is also larger and larger, buckling instability damage is easy to occur, and the corrugated steel web of the section near the fulcrum is restrained by lining concrete in general engineering so as to prevent the section from buckling. The Guangdong province Specification (DB 44/T1393-20147.2.2) states that the net height of a corrugated steel web should be less than 5m to prevent buckling instability of the web. However, with the increase of the bridge span, under the constraint of the high span ratio 1/15-1/17 of the support, when the span reaches more than 180m, the net height of the corrugated steel web at the fulcrum reaches 9-10 m, the web in the hogging moment area is ultrahigh, buckling instability is easy to occur, the bridge span is a limiting condition for the development of the bridge type span, and the self weight of the bridge is increased due to the arrangement of an overlong lining concrete section, so that the significance of arranging the corrugated steel web is lost.
Disclosure of Invention
The invention aims to solve the technical problem of providing a steel truss-corrugated steel web large-span composite beam bridge and a construction method thereof.
In order to solve the technical problems, the invention adopts the following technical scheme:
a steel truss-corrugated steel web beam section is arranged outside a support lining concrete section in a bridge.
The span of the large-span composite girder bridge is over 160 m.
The length of the beam section of the steel truss-corrugated steel web plate ensures that the net height of the corrugated steel web plate is more than 5m, and the stability safety factor of the corrugated steel web plate of the beam section is more than 2.0.
The steel truss-corrugated steel web beam section consists of a steel column, a compression steel truss, a tension steel truss, a node plate, a corrugated steel web, a steel upper flange plate and a steel lower flange plate.
The compression steel truss and the tension steel truss are connected in a separation type or a consolidation type, and the included angle between the compression pull rod and the tension pull rod and the horizontal line is 30-60 degrees.
The compression steel truss adopts a steel member or a steel pipe concrete member.
The steel upper flange plate and the steel lower flange plate are arranged in a rectangular or saddle shape.
Shear stiffness of steel truss
Is composed of
Wherein:
in the formula: a is the length of the steel upper flange plate, h is the length of the steel column, b is the length of the steel upper flange plate, and c is the distance from the lower end point of the tension steel truss to the steel upper flange plate.
The shearing forces respectively borne by the steel truss and the corrugated steel web are as follows:
in the formula: v is the shearing force borne by the steel truss-corrugated steel web beam section member, the shearing rigidity of the corrugated steel web is GA, G is the shear modulus of steel, and A is the section area of the steel web.
The construction method of the steel truss-corrugated steel web large-span combined beam bridge is operated according to the following steps:
<1> integrally prefabricating a steel truss-corrugated steel web member;
filling concrete in the compression steel truss;
after the construction of the supporting point lining concrete in the combined beam bridge is finished, the cantilever hoists the steel truss-corrugated steel web member;
and 4, casting the upper and lower concrete flange plates on site and hoisting the steel truss-corrugated steel web plate of the next section.
In order to meet the requirement that the shearing force borne by a large-span and dividable corrugated steel web plate is met so as to effectively prevent buckling instability of the corrugated steel web plate, the inventor designs a steel truss-corrugated steel web plate large-span combined beam bridge, and a steel truss-corrugated steel web plate beam section is arranged outside a support lining concrete section in the bridge. The steel truss-corrugated steel web beam section can effectively share the shear load of the beam section, prevent the corrugated steel web from buckling and buckling instability to cause structural damage, meet the design requirement of a large-span corrugated steel web bridge and solve the problem that the corrugated steel web of the outer side beam section of the lining of the large-span corrugated steel web bridge is too large to be sheared. Accordingly, the inventor also establishes a corresponding construction method. The invention is suitable for designing and using the bridge with span of 160m or more, and has certain engineering significance and great economic value.
Drawings
Fig. 1 is a schematic elevation view of a steel truss-corrugated steel web composite girder bridge according to the present invention.
FIG. 2 is a detailed view of a single steel truss-corrugated web hybrid, wherein: (a) the method is a schematic diagram of a rectangular arrangement method of the flange plate, (b) is a setting diagram of a saddle shape arrangement method of the flange plate, and (c) is a schematic diagram of a vertical plane of a single steel truss-corrugated steel web mixed part and a sectional diagram 1-1 thereof.
Fig. 3 is a schematic view of a connection method between a compression steel truss and a tension steel truss, wherein: (a) is a separation type connection, and (b) is a fixation type connection.
Fig. 4 is a schematic view of a split steel truss employed in the present invention.
Fig. 5 is a simplified diagram of the stress and constraint of the steel truss adopted by the invention.
Figure 6 is a deformation of the upper truss system consisting of the upper flange plate and the steel truss under pressure.
Fig. 7 is a coordinate system based on the dimensions of the upper truss before and after deformation, wherein the upper part is before deformation and the lower part is after deformation.
Fig. 8 is a deformation diagram of the lower truss system consisting of the lower flange plate and the tension steel truss.
Fig. 9 is a coordinate system based on the dimensions of the lower truss before and after deformation, wherein the upper part is before deformation and the lower part is after deformation.
Fig. 10 is a schematic view showing the completion of the construction of the fulcrum lining concrete in the composite girder bridge.
FIG. 11 is a schematic diagram of the first section of steel truss-corrugated steel web being hoisted and the upper and lower flange plates being poured when the present invention is applied
Fig. 12 is a schematic view of the construction completion of the steel truss-corrugated steel web composite beam bridge when the invention is applied.
Fig. 13 is a schematic elevation view of a steel truss-corrugated steel web rigid frame bridge of the steel truss-corrugated steel web composite girder bridge when the invention is applied.
Fig. 14 is a schematic view of the cross-sectional dimensions of a steel truss, wherein: (a) is a compression steel truss and (b) is a tension steel truss.
In the figure: 1 full-height concrete lining, 2 corrugated steel web plates, 3 upper flange plates, 4 lower flange plates and 5Lh(length of steel truss-corrugated steel web mixed beam section), 6 main piers and 7 middle pivot transverse partitionsThe steel truss-type connecting plate comprises a plate, 8 middle pivot webs, 9 compression steel trusses, 10 tension steel trusses, 11 gusset plates, 12 steel columns, 13PBL connecting keys, 14 angle steel connecting pieces, 15 steel upper flange plates, 16 steel lower flange plates and 17 fixed connecting plates.
Detailed Description
Basic structure and principle of large-span combined beam bridge with steel truss-corrugated steel web
The method adopts steel truss-corrugated steel web mixed shear, and arranges a steel truss-corrugated steel web beam section outside a support lining concrete section in the bridge, wherein the beam section has a length of LhSo as to share the problem that the corrugated steel web of the beam section is too large to be sheared (figure 1). Length L of steel truss-corrugated steel web beam sectionhThe net height of the corrugated steel web plate is more than 5m, and the stability safety factor of the beam section corrugated steel web plate is more than 2.0.
As shown in fig. 2, the steel truss-corrugated steel web beam section is composed of a steel column, a compression steel truss, a tension steel truss, a node plate, a corrugated steel web, a steel upper flange plate and a steel lower flange plate. Wherein, the compression steel truss adopts a steel member or a steel pipe concrete member. The steel upper flange plate and the steel lower flange plate are arranged in a rectangular or saddle shape. The compression steel truss and the tension steel truss can adopt a separation type or consolidation type connection method, and the included angle between the compression pull rod and the tension pull rod and the horizontal line (which should be controlled) is between 30 and 60 degrees (figure 3).
The shearing forces respectively borne by the steel truss and the corrugated steel web of the combined beam bridge are determined according to the shearing rigidity of the steel truss and the corrugated steel web.
Wherein the shear stiffness of the split steel truss (fig. 4) is calculated as follows:
the force of the steel truss can be simplified to the truss system analysis shown in fig. 5. The truss deformation in fig. 5 can be analyzed in two parts, see fig. 6-9, respectively. FIG. 6 is a deformation diagram of the upper truss system consisting of the upper flange plate and the compression steel truss, Delta1For truss node A under external force X1Vertical displacement, Δ L, taking place1For truss node A under external force X1The axial strain that occurs. FIG. 7 is a coordinate system based on the dimensions of the upper truss before and after deformation for calculating the external force X required to cause a unit vertical displacement of the truss node A1Size, i.e. countingAnd calculating the shear rigidity of the upper truss.
As can be seen from FIGS. 6-7:
according to the deformation coordination condition, the longitudinal coordinate y of the deformed truss node A is solved1：
From FIG. 7, the ordinate y of the deformed truss node A can be known1The vertical coordinate 0 of the truss node A before deformation reduction is equal to the vertical displacement of the truss node A, namely:
Δ1＝y1-0, unit displacement taken as Δ 11, get:
y1＝1 ②
substituting the second into the first to obtain:
axial strain and external force X are known from mechanics of materials1The relationship of (1):
from FIG. 7, F1And X1The relationship is as follows:
substituting the fourth step and the fifth step into the third step, and finishing to obtain:
i.e. the shear stiffness of the upper girder is
Similarly, fig. 8 is a deformation diagram of the lower truss system composed of the lower flange plate and the tension steel truss. Delta2For truss node B under external force X2Vertical displacement, Δ L, taking place2For truss node B under external force X2The axial strain that occurs. FIG. 9 is a coordinate system based on the dimensions of the lower truss before and after deformation for calculating the external force X required to cause a unit vertical displacement of the truss node B2And (4) calculating the shear rigidity of the lower truss. As can be seen from FIGS. 8-9:
according to the deformation coordination condition, the vertical coordinate y of the deformed truss node B is solved2：
FIG. 9 shows the ordinate y of the deformed truss node B2The ordinate c of the truss node B before deformation reduction is equal to the vertical displacement of the truss node B, namely:
Δ1＝y2c, taking the unit displacement Δ 11, get:
y2＝c+1 ⑦
substituting the seventh step into the sixth step to obtain:
from the axial strain formula:
from FIG. 9, F2And X2The relationship is as follows:
substituting ninthly and the sounds into the tool (b) to obtain:
i.e. the shear stiffness of the lower truss is
From the above analysis, it can be seen that the shear stiffness of the steel truss
Is (the reference numerals in the formula are shown in figure 6-figure 9):
wherein:
in the formula: a is the length of the steel upper flange plate, h is the length of the steel column, b is the length of the steel upper flange plate, and c is the distance from the lower end point of the tension steel truss to the steel upper flange plate.
The shearing forces respectively borne by the steel truss and the corrugated steel web (V is the shearing force borne by the steel truss-corrugated steel web beam section member) are as follows:
in the formula: the shear rigidity of the corrugated steel web is GA, G is the shear modulus of steel, and A is the section area of the steel web.
Construction method of large-span combined beam bridge with steel truss-corrugated steel web
<1> integrally prefabricating a steel truss-corrugated steel web member in a factory;
filling concrete in the compression steel truss according to the design requirement;
after the construction of the supporting point lining concrete in the combined beam bridge is finished, the cantilever hoists the steel truss-corrugated steel web member; (FIG. 10)
And 4, casting the upper and lower concrete flange plates on site and hoisting the steel truss-corrugated steel web plate of the next section. (FIGS. 11 and 12)
Application of three-steel truss-corrugated steel web large-span combined beam bridge
The design span of a corrugated steel web rigid frame bridge is (95+170+95) m, wherein the net height of the corrugated steel web at a fulcrum is 9.00m, a 15.40m lining concrete section is arranged on a beam section near a middle support, but the height of the corrugated steel web is still as high as 7.50m on the outer section where the 15.40m lining concrete is arranged.
To this end, with reference to the foregoing structure and method, steel truss-corrugated steel web beam sections, totaling 21.60m, 3 sections, each 8.00m, 7.20m, 6.4m in length, were provided outside the lining concrete beam sections.
As shown in FIG. 13, the thickness of the corrugated steel web in the A-B section is 24mm, the thickness of the corrugated steel web in the B-C section is 20mm, the thickness of the corrugated steel web in the C-D section is 18mm, and the thickness of the corrugated steel web in the D-E section is 16 mm. The corrugated steel web plate is made of 1600-type Q345D steel with the wave height of 200mm and the length of a straight line segment of 0.43 m. The stability safety coefficient n of the corrugated steel web before and after the arrangement of the steel truss is min { tau ═cr，I，fyd}/τdThe calculation is shown in tables 1 and 2.
Table 1 Web stability factor of safety (arranging steel truss front)
And in the section B-B, the thickness of the corrugated steel web is 20 mm: GA-0.0600E
Pressure lever A1Area of 230000mm2Pull rod A2Area of 100000mm2The following can be obtained:
cross-sectional dimension of the strut (fig. 14 (a)): b1＝800mm，h1＝1100mm，c1＝20mm
Tie rod cross-sectional dimension (fig. 14 (b)): b2＝600mm，h2＝1100mm，c2＝25mm
In the C-C section, the thickness of the corrugated steel web is 18 mm: GA-0.0487E
Pressure lever A1Area of 160000mm2Pull rod A2The area is 80000mm2The following can be obtained:
cross-sectional dimension of the strut (fig. 14 (a)): b1＝600mm，h1＝1000mm，c1＝16mm
Tie rod cross-sectional dimension (fig. 14 (b)): b2＝600mm，h2＝800mm，c2＝24mm
In the D-D section, the thickness of the corrugated steel web is 16 mm: GA 0.0393E
Pressure lever A1Has an area of 120000mm2Pull rod A2Area of 50000mm2The following can be obtained:
cross-sectional dimension of the strut (fig. 14 (a)): b1＝500mm，h1＝800mm，c1＝18mm
Tie rod cross-sectional dimension (fig. 14 (b)): b2＝500mm，h2＝800mm，c2＝18mm
TABLE 2 Web stability factor of safety (behind steel truss)
Claims (3)
1. A construction method of a steel truss-corrugated steel web large-span combined beam bridge is characterized by comprising the following steps of:
<1> integrally prefabricating a steel truss-corrugated steel web member;
filling concrete in the compression steel truss;
after the construction of the supporting point lining concrete in the combined beam bridge is finished, the cantilever hoists the steel truss-corrugated steel web member;
<4> cast-in-place upper and lower concrete flange plates and hoisting the steel truss-corrugated steel web of the next section;
the steel truss-corrugated steel web girder section is arranged outside a support lining concrete section in the bridge; the span of the large-span combined beam bridge is more than 160 m; the length of the beam section of the steel truss-corrugated steel web plate enables the net height of the corrugated steel web plate to be larger than 5m, and the stability safety coefficient of the corrugated steel web plate of the beam section to be larger than 2.0; the shear rigidity S of the steel trussTrussIs composed of
Wherein:
Lt＝a
in the formula: a is the length of the steel upper flange plate, h is the length of the steel column, b is the length of the steel upper flange plate, and c is the distance between the lower end point of the tension steel truss and the steel upper flange plate;
the steel truss-corrugated steel web beam section consists of a steel column, a compression steel truss, a tension steel truss, a gusset plate, a corrugated steel web, a steel upper flange plate and a steel lower flange plate; the compression steel truss and the tension steel truss are connected in a separation type or a consolidation type, and the included angle between the compression pull rod and the tension pull rod and the horizontal line is 30-60 degrees;
the shearing forces respectively borne by the steel truss and the corrugated steel web are as follows:
in the formula: v is the shearing force borne by the steel truss-corrugated steel web beam section member, the shearing rigidity of the corrugated steel web is GA, G is the shear modulus of steel, and A is the section area of the steel web. .
2. The construction method of the steel truss-corrugated steel web large-span composite girder bridge according to claim 1, wherein: the compression steel truss is a steel member or a steel pipe concrete member.
3. The construction method of the steel truss-corrugated steel web large-span composite girder bridge according to claim 2, wherein: the steel upper flange plate and the steel lower flange plate are arranged in a rectangular or saddle shape.
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