CN111335141A

CN111335141A - Antisymmetric beam-arch composite structure foot bridge

Info

Publication number: CN111335141A
Application number: CN202010112919.5A
Authority: CN
Inventors: 郑建东; 陈大汉; 王姝; 陈缔欣; 邱永兴; 黄福祥; 李建伟; 林骏; 叶其彬
Original assignee: Xiamen Municipal Engineering Design Institute Co ltd
Current assignee: Xiamen Municipal Engineering Design Institute Co ltd
Priority date: 2020-02-24
Filing date: 2020-02-24
Publication date: 2020-06-26

Abstract

The invention discloses an antisymmetric girder-arch combined structure pedestrian bridge, which comprises a first arch bridge part and a second arch bridge part which are arranged in an antisymmetric manner. First arch bridge portion and second arch bridge portion all include cushion cap, half arch ring, conversion platform, longeron, bracing combination and a plurality of pile foundation, and the cushion cap is fixed on a plurality of pile foundations, and the both ends of half arch ring are fixed respectively on cushion cap and conversion platform. The two ends of the longitudinal beam are respectively fixedly connected with the inclined strut combination and the conversion platform, the inclined strut combination is fixed on the bearing platform, the conversion platform of the first arch bridge part is fixedly connected with the conversion platform of the second arch bridge part, and the semi-arch ring is provided with a ladder footpath. The invention takes the advantages of two structural forms of beam and arch, combines a novel antisymmetric arched beam system through geometric relationship, and utilizes the connection of an arch ring and the ground to arrange a ladder footpath as a pedestrian passage. The structure has the characteristics of reasonable stress, strong bearing capacity, small deflection, safety, applicability, economy and attractiveness, and has no redundant structure, beautiful line and simple appearance.

Description

Antisymmetric beam-arch composite structure foot bridge

Technical Field

The invention belongs to the technical field of bridges, and particularly relates to a pedestrian bridge with an antisymmetric beam-arch combined structure.

Background

With the rapid development of social economy, the urbanization process of China is promoted and accelerated, and the requirement of people on improving the living environment is higher and higher. The bridge landscape design occupies an extremely important position in the urban landscape design, has obvious effect in improving urban livable environment, and the landscape and ornamental functions of the bridge are more and more emphasized by people, even some bridge designs place the landscape design on an important position. At present, bridge landscape design has some error zones: firstly, the bridge design is too pursuit of cost saving and convenient and fast to construct, so that the bridge style is too single and cannot meet the urban landscape requirements; secondly, the bridge design excessively attaches importance to the decoration of the appearance and provides landscape, the landscape design is disconnected with the bridge structure under stress, and the surplus decoration structure runs transversely.

Disclosure of Invention

In view of the above problems, the present invention provides a pedestrian bridge with an antisymmetric arch-girder composite structure, wherein the shape of the arch bridge integrates the shape and aesthetics of the arch bridge and the simple characteristics of the arch bridge, and the stress system of the structural body is coordinated and unified with the landscape shape of the bridge.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the utility model provides an antisymmetric beam-arch composite structure foot bridge, is including the first arched bridge portion and the second arched bridge portion that are antisymmetric setting each other. The first arched bridge part and the second arched bridge part respectively comprise a bearing platform, a half arch ring, a conversion platform, a longitudinal beam, an inclined strut combination and a plurality of pile foundations. The bearing platform is fixed on the pile foundations, and two ends of the semi-arch ring are respectively fixed on the bearing platform and the conversion platform. The two ends of the longitudinal beam are respectively fixedly connected with the inclined strut combination and the conversion platform, and the inclined strut combination is fixed on the bearing platform. The conversion platform of the first arch bridge part is fixedly connected with the conversion platform of the second arch bridge part, and the semi-arch ring is provided with a ladder footpath.

Furthermore, the inclined strut assembly comprises an inclined strut pier, a cap beam arranged at the top of the inclined strut pier and a connecting piece fixedly arranged on the side face of the cap beam, and one end of the longitudinal beam is fixedly connected with the connecting piece.

Preferably, the included angle between the inclined supporting pier and the bearing platform is not less than 90 degrees.

Preferably, the half arch ring and the longitudinal beam are both steel box girders, and the diagonal bracing pier is a reinforced concrete diagonal bracing pier.

Furthermore, the connecting piece comprises a panel, two ribbed bottom plates vertically arranged on two sides of the panel, two ribbed webs vertically arranged on two ends of the panel, a plurality of vertical perforated plates arranged along the length direction of the panel and parallel to the ribbed webs, and a plurality of rows of shear keys transversely penetrating through the vertical perforated plates. The panel is respectively welded with the ribbed bottom plate, the ribbed web plate and the vertical perforated plates in a penetration mode.

Shear nails are fixedly arranged on the inner sides of the panel, the ribbed bottom plate and the ribbed web plate respectively.

Wherein, the interval between any two adjacent vertical perforated plates is 100 cm.

The distance between any two adjacent rows of shear keys on the connecting piece is 25-35 cm.

Furthermore, a steel-concrete arch springing is pre-embedded at the joint of the bearing platform and the semi-arch ring, and the steel-concrete arch springing comprises a pre-embedded part partially pre-embedded in the bearing platform and arch springing reinforced concrete wrapped outside the pre-embedded part.

Furthermore, the embedded part comprises an end sealing plate, two ribbed bottom plates vertically arranged on two sides of the end sealing plate, two ribbed webs vertically arranged on two end parts of the end sealing plate, a plurality of perforated I-shaped steel arranged along the length direction of the end sealing plate, and a plurality of rows of shear keys transversely penetrating through the perforated I-shaped steel. One end of the perforated I-shaped steel is fixedly connected with the end sealing plate, the other end of the perforated I-shaped steel is embedded in the bearing platform, the end sealing plate is respectively welded with the ribbed bottom plate, the ribbed web plate and the perforated I-shaped steel in a penetration mode, and one end of the semi-arch ring is fixedly connected with the end sealing plate.

Wherein, the distance between any two adjacent perforated I-shaped steel is 50 cm.

The distance between any two adjacent rows of shear keys on the embedded part is 25-35 cm.

The invention has the following beneficial effects: combining the advantages of two structural forms of the beam and the arch, combining the two structural forms into a novel anti-symmetric beam arch system through geometric relationship, and arranging the pedestrian ladder footpath by utilizing the connection of the arch rings and the ground. The structure system has the advantages of attractive and soft line type of the arch bridge, simple structure of the bridge and simple and compact appearance, reasonable stress of the structure, good overall performance, small deflection and strong bearing capacity, provides a quick and comfortable interchange stairway, has no redundant structure, simple shape, soft appearance, safety, applicability, economy and attractiveness.

Drawings

Fig. 1 is a schematic perspective view of the present invention.

Fig. 2 is a bridge-type elevation view.

Fig. 3 is a bridge type plan view.

Fig. 4 is a construction flow chart of the pile foundation.

FIG. 5 is a construction flow chart of the combination of the bearing platform and the inclined strut.

Fig. 6 is a construction flow chart of the half arch ring, the conversion platform and the longitudinal beam of the half-width foot bridge.

FIG. 7 is a construction flow chart of the half arch ring, the conversion platform and the longitudinal beam of the other half of the foot bridge.

Fig. 8 is a schematic cross-sectional view of a stringer.

Fig. 9 is a schematic cross-sectional view of a conversion platform.

Fig. 10 is a schematic cross-sectional view of a half arch ring.

FIG. 11 is a schematic view of the brace assembly, cap beam and connector.

FIG. 12 is a schematic view of the arch springing and the embedment.

FIG. 13 is a schematic cross-sectional view of a stringer and cap stringer interface.

Fig. 14 is a schematic top cross-sectional view of the arch springing.

Fig. 15 is a schematic cross-sectional view of the bottom of the arch.

Fig. 16 is a perspective view of the connector.

Fig. 17 is a perspective view of the connector at another angle.

Fig. 18 is a schematic perspective view of an embedded part.

FIG. 19 is a schematic perspective view of another angle of the embedment.

FIG. 20 is a finite element model diagram of a pedestrian bridge according to the present invention.

FIG. 21 is a graph of beam height versus frequency.

FIG. 22 is a graph of beam height versus deflection.

FIG. 23 is a graph of beam height versus combined stress.

Fig. 24 is an analysis diagram of the axial displacement results when the end of the stringer is simply supported.

Description of the main component symbols: 101. a first arch bridge; 102. a second arch bridge; 10. a shear key; 100. shear nails; 11. a bearing platform; 12. a semi-arch ring; 120. a ladder walk; 13. a conversion platform; 141. a stringer; 142. combining inclined struts; 143. obliquely supporting the pier; 144. a cap beam; 145. a connecting member; 146. a panel; 147. a ribbed bottom plate; 148. a ribbed web; 149. a vertical perforated plate; 15. a pile foundation; 161. embedding parts; 162. arch foot reinforced concrete; 163. an end sealing plate; 164. a ribbed bottom plate; 165. a ribbed web; 166. punching I-shaped steel.

Detailed Description

The invention is further described with reference to the following drawings and detailed description.

As shown in fig. 1 to 24, the passenger bridge with the antisymmetric beam-arch combined structure comprises a first arched bridge part 101 and a second arched bridge part 102 which are arranged in an antisymmetric manner, wherein each of the first arched bridge part 101 and the second arched bridge part 102 comprises a bearing platform 11, a half-arch ring 12, a conversion platform 13, a longitudinal beam 141, a bracing combination 142 and a plurality of pile foundations 15. The bearing platform 11 is fixed on a plurality of pile foundations 15, two ends of the semi-arch ring 12 are respectively fixed on the bearing platform 11 and the conversion platform 13, one end of the longitudinal beam 141 is fixedly connected with the conversion platform 13, the other end of the longitudinal beam is fixedly connected with the inclined strut combination 142, and the inclined strut combination 142 is fixed on the bearing platform 11. The conversion platform 13 of the first arch bridge 101 is fixedly connected with the conversion platform 13 of the second arch bridge 102, and the half arch ring 12 is provided with a ladder way 120.

As shown in fig. 11, the bracing assembly includes a bracing pier 143, a cap beam 144 fixed to the top of the bracing pier 143, and a connecting member 145 fixed to the inside of the cap beam 144. As shown in fig. 16 and 17, the connecting member 145 includes a panel 146, two ribbed bottom plates 147 vertically disposed at both sides of the panel 146, two ribbed webs 148 vertically disposed at both ends of the panel 146, a plurality of vertical perforated plates 149 arranged along the length direction of the panel 146 and parallel to the ribbed webs 148, and a plurality of rows of shear keys 10 transversely disposed through the vertical perforated plates 149. Two ends of the longitudinal beam 141 are respectively fixedly connected with the conversion platform 13 and the connecting piece 145, the inclined support pier 143 is fixed on the bearing platform 11, an acute included angle is formed between the longitudinal beam 141 and the inclined support pier 143, the longitudinal beam 141 is a steel box beam, and the inclined support pier 143 is a reinforced concrete inclined support pier. The distance between any two adjacent vertical perforated plates 149 is 100cm, and the distance between any two adjacent rows of shear keys 10 is 25-35 cm. The face plate 146 is fusion welded to the ribbed bottom plate 147, ribbed web 148 and vertical perforated plates 149, respectively. Shear nails 100 are respectively fixedly arranged on the inner sides of the face plate 146, the ribbed bottom plate 147 and the ribbed web 148.

As shown in fig. 12, the connecting portion of the half-arch ring 12 and the bearing platform 11 is provided with a steel-concrete arch springing, and the steel-concrete arch springing comprises an embedded part 161 which is partially embedded in the bearing platform 11 and an arch springing reinforced concrete 162 which is wrapped outside the embedded part 161. As shown in fig. 18 and 19, the embedded part 161 includes an end sealing plate 163, two ribbed bottom plates 164 vertically disposed at both sides of the end sealing plate 163, two ribbed webs 165 vertically disposed at both ends of the end sealing plate 163, a plurality of perforated i-shaped steel 166 disposed along a length direction of the end sealing plate 163, and a plurality of rows of shear keys 10 transversely disposed through the perforated i-shaped steel 166. The distance between any two adjacent perforated I-shaped steel 166 is 50cm, and the distance between any two adjacent rows of shear keys 10 is 25-35 cm. One end of the perforated I-shaped steel 166 is fixedly connected with the end sealing plate 163, the other end of the perforated I-shaped steel is embedded in the bearing platform 11, the end sealing plate 163 is respectively welded with the ribbed bottom plate 164, the ribbed web 165 and the perforated I-shaped steel 166 in a penetration manner, and one end of the semi-arch ring 12 is fixedly welded with the end sealing plate 163.

As shown in fig. 4 to 7, the construction steps of the pedestrian bridge of the present invention are as follows:

firstly, leveling the field, constructing a pile foundation 15 and a bearing platform 11, embedding embedded parts 161 when the bearing platform 11 is poured, and embedding diagonal brace pier 143 steel bars in a diagonal brace combination 142.

Filling or excavating a side slope and compacting, arranging a concrete cushion layer, pouring an inclined strut combination 142 on the concrete cushion layer, wherein the inclined strut combination comprises an inclined strut pier 143, a reinforced concrete cap beam 144, a pre-embedded connecting piece 145 arranged on the side surface of the reinforced concrete cap beam 144, pouring arch foot reinforced concrete 162 through a support, and wrapping the pre-embedded piece 161 to form the reinforced concrete arch foot.

a) The embedment 161 is composed of a perforated i-beam 166, an end seal plate 163, a ribbed bottom plate 164 and a ribbed web 165.

b) The perforated I-shaped steel 166 is embedded in the bearing platform 11 in parallel at intervals of 50cm,

c) transverse through holes with the distance of 20cm are arranged in the web plate of the perforated I-shaped steel 166, and the shear key 10 is arranged in the through holes.

d) The shear nails 100 are uniformly arranged on the concrete inner sides of the ribbed bottom plate 164, the ribbed web 165 and the end sealing plate 163.

e) The perforated I-shaped steel 166 is fusion-welded with the end sealing plate 163, the ribbed bottom plate 164 and the ribbed web 165.

And thirdly, erecting the steel box semi-arch ring 12 on the support and welding the steel box semi-arch ring with an end sealing plate 163 of the embedded part 161.

Fourthly, erecting a steel box conversion platform 13 on the support and welding the steel box conversion platform with the steel box semi-arch ring 12.

Fifthly, one end of a longitudinal beam 141 erected on the bracket is welded with the conversion platform 13, and the other end of the longitudinal beam is welded with a connecting piece 145 on the side surface of a cap beam 144 at the top of the inclined strut assembly 142 to form a half-width bridge; and constructing the other half of the arch bridge according to the flow 1-5 to form the integral antisymmetric arch bridge.

a) The connecting member 145 is composed of a steel panel 146, vertical perforated plates 149 arranged in parallel at intervals of 100cm, a ribbed bottom plate 147 and a ribbed web 148.

b) Vertical perforated plates 149 are arranged in parallel at intervals of 100cm inside the cap beam 144.

c) The vertical perforated plate 149 is provided with perforations at intervals of 20cm, and the shear key 10 is arranged in the perforations.

d) The shear nails 100 are uniformly arranged on the concrete inner sides of the steel face plates 146, the ribbed bottom plates 147 and the ribbed web plates 148.

e) The steel panel 146 is fusion welded with the ribbed bottom plate 147, the ribbed web 148 and the vertical perforated plate 149. Laying auxiliary components such as the top stairway 120 of the arch section, railings and the like.

The performance change conditions of the pedestrian bridge under various loads are compared and analyzed by adopting an MIDAS finite element model analysis method, and the analysis process and the result are detailed as follows.

1. Analytical procedure

In the analysis, the size parameters of each part of the pedestrian bridge with the antisymmetric beam-arch combined structure are set as follows, the total length of the pedestrian bridge is 40m, the distance between two half arch rings 12 of the pedestrian bridge is 26m, the rise is 3.5m, the single total width of the pedestrian bridge is 3.0m, the total width of a conversion platform 13 is 6.3m, the section of a longitudinal beam 141 is a rectangular section, the size is 3.0m (width) × 0.8.8 m (height), the top plate thickness of the section of the longitudinal beam 141 is 20mm, the bottom plate thickness is 20mm, a web plate thickness is 20mm, a lower bearing platform 11 is set to be 7.5mx4.5mx1.5m and phi 100cm pile foundation 15, the transverse distance of the pile foundation 15 is 5.8m, the longitudinal distance is 2.5m, and a beam height increasing section is arranged in the range from the top of the longitudinal beam 141 to the cap beam 144 side of the inclined strut combination 142.

And analyzing and calculating the structure by adopting a finite element method, wherein the adopted software is MIDAS finite element software. The full bridge finite element model is shown in fig. 20. The full bridge has 280 nodes and 266 units.

1) Frequency analysis

The natural frequency of the structure refers to the inherent characteristic of the structure that the displacement of the structure changes according to a sine law with time when the structure does free vibration. The natural frequency of the structure is related to the rigidity, the mass and the external dimension of the structure, and when the structure is deformed, the elastic force enables the structure to be deformed and recovered. The spring force is mainly related to the size and structural rigidity, and the mass affects the acceleration. In the same shape, the frequency is high when the structural rigidity is larger, and the frequency is low when the mass is larger. The natural frequency of the structure under the action of the dead load is an important parameter for reflecting the overall state of the bridge.

Through analysis, the frequency theory analysis result of the pedestrian bridge is shown in fig. 21, wherein the horizontal coordinate is the height (unit: m) of the longitudinal beam 141 (the half arch ring 12 and the conversion platform 13), and the vertical coordinate is the frequency value (unit: Hz). The calculation result shows that the vertical reference frequency of the longitudinal beam 141 (the half arch ring 12 and the conversion platform 13) at four heights meets the requirement. As can be seen from fig. 21, the longitudinal beams 141 (the half arch rings 12 and the transition platforms 13) are heightened within a certain range, so that the rigidity of the whole pedestrian bridge can be improved, and the linear variation trend is basically presented.

2) Deflection analysis

The deflection refers to the linear displacement of the centroid of the cross section along the direction vertical to the axis when the member is bent and deformed, and is called the deflection, and the deflection is related to the load size, the sectional dimension of the member and the material physical property of the member. Through analysis, a deflection result curve chart of the pedestrian bridge is shown in fig. 22, wherein the horizontal coordinate is the height (unit: m) of the longitudinal beam 141 (the half arch ring 12 and the conversion platform 13), and the vertical coordinate is the mid-span deflection value (unit: mm). Under the action of a moving load, the span-middle deflection values of the longitudinal beams 141 (the half-arch rings 12 and the conversion platforms 13) at four heights are small, the overall performance of the pedestrian bridge is well maintained, and the requirement of the specification is met.

3) Stress

The analysis on the calculation and analysis of different beam heights and different plate thicknesses of the structure shows that the stress analysis result of the pedestrian bridge is shown in fig. 23, the theoretical result of the stress of the worst load position is good, the stress results are both about 110MPa and meet the requirements, and the specific gravity of the temperature stress is the maximum (shown in table 1); as the wall thickness of the pedestrian bridge structure is reduced, all indexes are increased to a certain extent and are within the range of material performance requirements, and optimization guidance can be provided for design (as shown in a table 2).

Table 1: stress gauge under each load working condition under beam height change

Wall thickness	Combined results of stress	Deflection	Fundamental frequency
				mm	(MPa)	mm	HZ
20	112.4	9.3	6.75
				18	115.1	10	6.78
16	118.1	10.9	6.81
				14	121.4	12.1	6.83
12	124.9	13.6	6.83

Table 2: index table for each load working condition under plate thickness change when beam height is 0.8m

4) The end of the longitudinal beam is set as result data (as shown in figure 24) simply supported on the inclined strut pier (upright pier)

The stress table under each load condition under the change of the beam height is shown in table 1, and when the end part of the longitudinal beam 141 is set to be simply supported and placed on a pier, the stress theoretical result of the worst load position is still good: the fundamental frequency is 5.1Hz, the combined stress is 90.6MPa, the vertical displacement is 11.2mm, and the horizontal displacement is 7.6 mm.

2. Analysis results

From the above analysis, the following conclusions can be drawn:

(1) each performance index of the pedestrian bridge under the action of each working condition can better meet the standard requirement.

(2) According to the calculation result, when the height of the cross-section beam is 0.7-1.0 m, the pedestrian bridge has good performance in all aspects, and the deflection result changes rapidly, which is a control factor of the structure.

(3) According to the calculation result, the temperature is used as the main influence factor of the stress of the structure due to the solidification of the arch springing, and the structural stress caused by settlement is increased continuously when the height of the beam is increased.

(4) After the end part constraint of the longitudinal beam 141 is horizontally released by the footbridge, all indexes are still good, and the axial displacement at the release position is slightly increased.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. The utility model provides an antisymmetric beam-arch integrated configuration passenger bridge which characterized in that: including being first arched bridge portion and the second arched bridge portion that antisymmetric set up each other, first arched bridge portion and second arched bridge portion all include cushion cap, half arch ring, conversion platform, longeron, bracing combination and a plurality of pile foundation, the cushion cap fix on a plurality of pile foundations, the both ends of half arch ring are fixed respectively on cushion cap and the conversion platform, the both ends of longeron respectively with bracing combination and conversion platform fixed connection, the bracing combination fix on the cushion cap, the conversion platform of first arched bridge portion and the conversion platform of second arched bridge portion are fixed continuous, half arch ring on be equipped with the ladder pavement.

2. The pedestrian bridge of an antisymmetric beam-arch combination structure as claimed in claim 1, wherein: the inclined strut combination comprises an inclined strut pier, a cap beam arranged at the top of the inclined strut pier and a connecting piece fixedly arranged on the side face of the cap beam, and one end of the longitudinal beam is fixedly connected with the connecting piece.

3. The pedestrian bridge of an antisymmetric beam-arch combination structure as claimed in claim 2, wherein: the included angle between the inclined supporting pier and the bearing platform is not less than 90 degrees.

4. The pedestrian bridge of an antisymmetric beam-arch combination structure as claimed in claim 2, wherein: the semi-arch ring and the longitudinal beam are steel box girders, and the inclined supporting piers are reinforced concrete inclined supporting piers.

5. The pedestrian bridge of an antisymmetric beam-arch combination structure as claimed in claim 2, wherein: the connecting piece include the panel, establish two ribbed bottom plates in the panel both sides perpendicularly, establish two ribbed webs at the panel both ends perpendicularly, lay and be on a parallel with along panel length direction a plurality of vertical perforated plates that ribbed web set up and transversely run through a plurality of rows of shear force keys that vertical perforated plate set up, the panel respectively with ribbed bottom plate, ribbed web and a plurality of vertical perforated plate weld all around thoroughly.

6. An antisymmetric beam-arch composite-structure footbridge as claimed in claim 5, characterized in that: and shear nails are fixedly arranged on the inner sides of the panel, the ribbed bottom plate and the ribbed web plate respectively.

7. An antisymmetric beam-arch composite-structure footbridge as claimed in claim 5, characterized in that: the distance between any two adjacent vertical perforated plates is 100 cm.

8. An antisymmetric beam-arch composite-structure footbridge as claimed in claim 5, characterized in that: the distance between any two adjacent rows of shear keys on the connecting piece is 25-35 cm.

9. The pedestrian bridge of an antisymmetric beam-arch combination structure as claimed in claim 1, wherein: the steel-concrete arch springing comprises an embedded part and arch springing reinforced concrete, wherein the embedded part is partially embedded in the bearing platform, and the arch springing reinforced concrete is wrapped outside the embedded part.

10. The pedestrian bridge of an antisymmetric beam-arch composite structure as claimed in claim 9, wherein: the embedded part include the end shrouding, establish perpendicularly two ribbed bottom plates in end shrouding both sides, establish perpendicularly two ribbed webs at end shrouding both ends, along a plurality of perforation I-shaped steel that end shrouding length direction laid, transversely run through a plurality of rows of shear force keys that perforation I-shaped steel set up, the one end of perforation I-shaped steel with end shrouding fixed connection, the other end is pre-buried in the cushion cap, the end shrouding respectively with ribbed bottom plate, ribbed web and perforation I-shaped steel weld all around thoroughly, the one end of half bow-turn with end shrouding fixed connection.

11. The pedestrian bridge of an antisymmetric beam-arch composite structure as claimed in claim 10, wherein: the distance between any two adjacent perforated I-shaped steel sections is 50 cm.

12. The pedestrian bridge of an antisymmetric beam-arch composite structure as claimed in claim 10, wherein: the distance between any two adjacent rows of shear keys on the embedded part is 25-35 cm.