RU2280121C1 - Bridge span structure erection method - Google Patents

Abstract

FIELD: building, particularly to erect small-scale and medium-scale bridges over rivers, rail roads, overpasses, to construct span sections of overpasses, trestles and floor structures.

SUBSTANCE: method for span structure erection by metal part mounting and by following reinforced concrete section connection involves mounting metal part of at least two mounting units, wherein each mounting unit is composed of two spaced apart metal main tubular beams so that distance between tubular beams is equal to tubular beam diameter and tubular beams are connected with each other by arch-shaped shell formed of tube half having diameter equal to tubular beam diameter, mounting units are connected with each other by two overlapped arch-shaped connection members extending along main beam sides; installing tension bars in each tubular beam; arranging transversal ties in each arch-shaped shell so that transversal ties and tension bars are arranged in horizontal planes, spaced apart along unit length and connected with each other in cross-section to create integral transversal links in the unit; installing stiffening members with central orifices inside each main beam; welding rod-like thrusts to upper mounting unit surface in staggered order; connecting mounting units with each other by overlapping two arch-shaped connection members one to another to create single arch-shaped shell having diameter equal to main beam tube diameter. Reinforced concrete section is solid.

EFFECT: simplified structure, reduced time of bridge erection in difficult-to-access areas.

3 cl, 10 dwg

Description

The present invention relates to civil engineering and can be used in the construction of the corresponding span structures, in particular bridges, overpasses, ceilings built through rivers, railways, overpasses, in which it is advisable to use structural elements combined from metal and concrete.

From the description of the invention “Steel-reinforced concrete span” and its drawing, see (USSR Author's Certificate No. 1825837, Mcl E 01 B 09/02, BI-25-93) there is a known method of erecting the span of the bridge, on which steel tubular beams with pre-installed bands with baited nuts set in the design position on the supports. Then they are connected by transverse ties and tighten the nuts on the bands, providing the required compression of the cross section of the pipe. After that, supporting elements made of a wooden beam with a wedge are laid on horizontal ties, and on them is a non-removable thin-sheet formwork. The pin stops are welded to the upper parts of the pipes of the inner surface of the formwork, which monopolize the reinforced concrete of the plate.

However, this known method of construction of the bridge span has a significant drawback, which is that the known method is difficult to implement and requires large financial costs, due to the need to place each tubular main beam in the design position on the support at the place of construction of the bridge, then connect them cross ties.

A known method of construction of the bridge span (see RF Patent 2041312, E 01 D 21/00, E 01 D 101: 26, publ. 1995.08.09), including the installation of the steel part of the span and the subsequent implementation of its concrete part, and the concrete part performed by spraying concrete on a steel part, which is used as a profiled sheet, then connect the concrete to the profiled sheet with fasteners, while spraying the concrete is carried out in sections and in layers with the possibility of at least partial setting of the concrete of the previous layer, while it is advisable to place iron or steel elements between concrete layers; spray concrete on both surfaces of the profiled sheet; layers to be made of various concrete; as concrete, use fiber-reinforced concrete or lightweight concrete with aggregate in the form of fibers or porous granules; to carry out a profiled sheet with a grid; attach the mesh to the profiled sheet, at least in areas forming in the direction of spraying the gutter, and it is possible to place the mesh in a recess that is preliminarily formed on the profiled sheet, and compress the profiled sheet in adjacent to the mesh sections for attaching the mesh, and to connect the profile a sheet of concrete on a profiled sheet to form holes with jagged edges or corrugations, for example, of variable width in the transverse direction.

This well-known technical solution is selected as a prototype, since with the claimed invention has the greatest number of common essential features and solves a similar problem with it. In addition, this well-known technical solution is the latest development on the claimed topic.

However, the prototype has a significant drawback, which consists in the fact that all operations for the construction of the span of the bridge must be performed sequentially and at the site of the construction of the bridge, which is difficult to implement especially in hard-to-reach geographical places. This is especially true for the installation of the steel part, performed elementwise, and the subsequent formation on it of the elementwise concrete part.

The present invention is the creation of a new method of construction of the bridge span, in which it would be possible to implement the modular principle of the construction of the bridge span, to ensure its rapid construction in an inaccessible geographical location and at the lowest cost.

The problem is solved as follows. In the known method of erecting the bridge span by mounting a metal part and then applying a concrete part to it, according to the present invention, the metal part is mounted from at least two mounting blocks, each of which first has at least two main beams placed at a distance from each other, equal to the diameter of the pipe, and connected by an arched sheath, which is preliminarily made from a half-pipe having a diameter equal to the diameter of the pipe, then inside each main beam they are installed rods, in each arched sheath - cross-links, which, together with the strands, are placed in a horizontal plane and dispersed along the length of the block, and connected in cross-section to form uniform cross-links in the block, while elements are placed in the supporting sections inside each main beam stiffness with a central hole, the stops are made in the form of pins and arrange them in a checkerboard pattern perpendicular to its upper surface, and then connect the mounting blocks to each other by overlapping two arc-shaped connecting elements with the formation of them arched shell in the form of a half-pipe having a diameter equal to the diameter of the main beam pipe, each of which is pre-installed on the sides of each mounting block, and the reinforced concrete part is made monolithic.

There is an option that develops the main technical solution, according to which metal pipes, which play the role of main beams, and half pipes connecting them, are also fastened to each other with the help of cords and transverse ties, respectively, with cords and transverse ties set horizontally.

There is a development option for the initial technical solution, according to which a monolithic reinforced concrete slab is formed of two layers, of which the lower layer is pre-laid on each mounting block and made of reinforced concrete or fiber-reinforced concrete, forming the module of the span from the last, and the upper one is laid over the entire width of the span from reinforced concrete.

Such a new technical solution with all its essential features allows us to achieve a technical result, which consists in the implementation of the modular principle of the construction of the bridge span structure, its rapid construction in an inaccessible geographical location and at the lowest cost. In addition, the volume of reinforced concrete work is reduced, as well as the volume of metal used and the number of nomenclature units used to erect the bridge span. This is due to the fact that in the present invention, the construction of the bridge span is carried out from at least two mounting blocks. At the same time, each of them is prefabricated in the factory and / or on site and is easily delivered to the installation site, especially in hard-to-reach places, for example, in the areas of laying gas and oil pipelines. This allows the on-site use of gas and oil pipelines for the construction of the bridge span, including pipes classified as used or recognized as substandard.

Compared with the prototype, the proposed technical solution has significant differences, which are as follows:

- pre-factory conditions or at the installation site of the bridge span from the metal tubular main beams form the mounting blocks, from which then form the metal part of the bridge span;

- tubular main beams are connected by arched shells made of half pipes having a diameter equal to the diameter of the main beam pipe;

- metal arched shells of half pipes and arched connecting elements are installed between the tubular main beams, form a wave-shaped upper part at the mounting block, providing rigidity in the longitudinal and transverse directions;

- a monolithic reinforced concrete part is erected on top of the metal part, and it is erected on the corrugated surface of the metal part serving as a formwork and having stops in the form of pins that are staggered perpendicular to the surface of the metal part. Due to this, the monolithic concrete part works well over the entire surface of the bridge span to separate from the metal part;

- the upper undulating metal part of the span consists of equally curved arched shells, which allows you to create an arched effect in the concrete part when loading the span with a local load between the main beams, since the “concrete arches” are the same in size and there is no spread in them, t. to. reinforced concrete works equally efficiently in compression;

- on top, each mounting block has either a reinforced concrete or fiber-reinforced concrete slab, on top of which, in the process of combining into a span, a common monolithic reinforced concrete slab is formed. This increases the bearing capacity of the main beams at the first stage of loading the span and accelerates the process of erection of the span, because after each installation, a technician can move through each mounting block.

The applicant conducted a patent information search, during which the claimed combination of essential features was not found. Therefore, the present invention can be considered new.

The proposed technical solution corresponds to the inventive step, since for a specialist of average skill the present invention does not logically follow from the prior art and is unexpected for him. So, for example, in the proposed technical solution, a uniform wavy surface is formed near the metal part of the bridge span. Moreover, its metal part is formed from prefabricated mounting blocks, which improves the assembly conditions of the span of the bridge, reduces its metal consumption and increases reliability and strength, because prefabricated blocks are easier to test for strength. In addition, on the surface of the metal part in a checkerboard pattern along the entire length of the monolithic block, stops in the form of pins are installed perpendicular to it. Such an installation is known from RF patent No. 2143023, IPC E 01 D 12/00, 1999.12.30. It is made not on a wavy surface, but on a surface of a different shape. In the present invention, they are installed on a uniform wave-shaped surface, which, in combination with the mentioned pins, allows you to have a monolithic reinforced concrete part of the bridge span, combining its mounting blocks in it into a single bridge structure.

The technical nature of the claimed invention is illustrated in the drawing, where:

figure 1 is a transverse section of the mounting block span;

figure 2 - node connection arched shell with the main beam;

figure 3 is a view of the upper part of the span of the bridge mounted on it with elastic pins;

figure 4 - installation diagram of the mounting blocks of the span on the supports;

5 is a cross-sectional view of the mounting blocks of the superstructure during their installation on the supports;

6 is a node connecting the mounting blocks to each other;

Fig.7 is a cross section of the mounting block after combining them in the span with a monolithic plate;

Fig - scheme concreting slab span;

Fig.9 is a cross section of the span of the bridge;

figure 10 is a view of the facade of the superstructure of the bridge.

The practical applicability of the present invention is explained below by the following description. A model was created in the form of a three-span bridge. The bridge span was designed under the load of A-11, NK-80. Dimension of the G-11.5 carriageway with two service walkways of 0.75 m each.

This span of the bridge consists of four mounting blocks, the connection of which forms the span (Fig.9). In each mounting block 1 and 2, metal tubular main beams 3 (see FIG. 1) are located in the transverse direction at a distance L = 820 mm from each other. Tubular main beams 3 are made of pipes with a diameter of D = 820 mm, wall thickness of 8 mm, strength class K55, with thermal hardening (Pipe type 3-U820-7-K55 GOST 20295-85). Pipes are manufactured in accordance with the requirements of GOST 20295-85 "Steel pipes for main gas and oil pipelines." In the tubular main beams 3, in the half-pipe 4 and in the arcuate connecting elements 5 made of the same pipes as the main beams, holes are drilled with a step m = 3480 mm along the length of the mounting block (Figs. 1 and 10). To the transverse ties 7 made of corners 100 × 100 × 5, 10 mm thick strips with holes are welded at the ends so that the holes in the strips coincide with the holes in the half pipe 4 (Fig. 2). At the construction site or in the factory, the main beams 3 are located at a distance L = 820 mm from each other, which in this case is equal to the diameter of the pipe used for the main beams. Between them, a half-pipe 4 is installed, and on the sides of the main beams 3, arcuate connecting elements 5 are mounted on auxiliary temporary scaffolds (not shown in the drawing) (Fig. 1). Then they connect everything into a single structure using strands 6 with a diameter of d = 20 mm, which are passed through the holes in the main beam 3, in the half-pipe 4, in the arcuate connecting elements 5 and the cross-braces 7 (Figs. 1 and 2). After that, tighten the nuts 8 to a design force of 5 tons using a torque wrench. After achieving the required compression of the cross section of the tubular main beam 3, a half-pipe 4 and arcuate connecting elements 5 are welded to its lateral surface 5. After that, supporting ribs 9 of 10 mm thick with a central hole d = 450 mm are welded in the supporting sections (Fig. 10) provides 3 convection processes in the pipe, which eliminates the accumulation of water inside the pipe. Flexible stops 10 with a length of 100 mm are welded perpendicularly to the upper wavy surface of the mounting block using the Hephaestus machine or another similar one. The Hephaestus welding machine is an experimental portable device designed for submerged arc welding of T-joints (TIP T1-MF) of large embedded products in reinforced concrete structures, including according to the technology of external reinforcement and during the installation of galvanized profiled flooring, as well as for welding of flexible stops (anchors) of steel-reinforced concrete spans. Flexible stops (anchor) 10 are made of scraps of class AIII reinforcement with a diameter of 16 mm and are staggered on the main beams 3, half pipes 4 and arcuate connecting elements 5 along the length of the span mounting block (Fig. 3). The pitch of the stops varies along the length of the mounting block from 400 mm near the support to 800 mm in the middle of the span (not shown in the drawing). To ensure the speed of assembly, durability and bearing capacity of the span prior to installation on supports at the construction site, the bottom monolithic slab 11 (Fig. 1) is made of reinforced concrete of strength class B25 reinforced with class AIII reinforcement with a diameter of 14 mm. It is more preferable if it is possible to concrete from fiber-reinforced concrete, since fiber-reinforced concrete has several times higher tensile and shear strength, impact and fatigue strength, fracture toughness and fracture toughness, frost resistance, water resistance, cavitation resistance, heat resistance and fire resistance.

Fiber concrete can be 15-20 times superior to concrete in terms of destruction performance. Fiber concrete is much more convenient to seal with a vibrator at the junctions of the half-pipes 4 and the main tubular beams 3. The assembly of all mounting blocks at all stages is carried out using a Ks4561 crane with a lifting capacity of 16 tons.

After assembling the supports 13, before the installation of the spans, geodetic control is carried out with the simultaneous application of marks for the installation of the mounting blocks of the spans. On the aligned and cleaned sub-trusses, the rubber and support parts of the ROCh 40 are installed (not shown in the drawing). Span mounting blocks are mounted sequentially in-flight. In each span, a distant mounting block 1 is installed. The parking lots of the crane 12 are determined from the installation condition of the blocks without raising or lowering the boom (Fig. 4). The installation of racks, nozzles, mounting blocks of the span is carried out by an RDK-25 crane with a lifting capacity of 25 tons. To connect the mounting blocks to the span to the arcuate connecting elements 5, two fixing rods d = 20 mm from class A-III fittings are welded on the block edges. Holes are made in the adjacent block at the edges. Adjacent blocks are overlapped by a value of h = 30 mm so that the locking rods enter the hole. Arcuate connecting elements 5 are welded along the end along the entire length of the mounting block (FIGS. 5 and 6).

A common monolithic reinforced concrete slab of strength class 15 B35 is arranged after installation and acceptance of a structure from mounting blocks. For the construction of a monolithic slab, formwork is installed only along the edges of the span (not shown in the drawing). After that, lay the reinforcing mesh 14 (Fig.7). Longitudinal reinforcement - rods of class A III with a diameter of 14 mm with a pitch of 150 mm. Transverse reinforcement - 12 mm in diameter with a pitch of 200 mm. A monolithic reinforced concrete slab 15 is concreted with a concrete pump 16 either from an adjacent span mounted span (Fig. 8) or from the ground. After curing, the concrete is dismantled. Metal structures of superstructures must accept all mounting loads without including reinforced concrete slab 15. During concreting, slab 15 is given a slope of 2% from the middle to the edges to ensure drainage without increasing the thickness of the roadway, the roadway of the roadway overpass is arranged by laying waterproofing from isoplast material - 5.5 mm, a protective layer - 40 mm and a two-layer asphalt concrete coating - 70 mm. After that, railing and barrier fences are installed (Fig.9).

The bridge span was designed and calculated according to SNiP 2.05.03-84 * "Bridges and pipes". As a result, the following numbers were obtained:

The calculated voltage in the main beam (pipe) at the first stage of the construction prior to the inclusion of reinforced concrete slab 15 in the work.

σn ¹ = 545 kg / cm ² is the voltage in the lower fiber of the pipe.

σv ¹ = 421 kg / cm ² is the voltage in the upper fiber of the pipe.

The rated voltage in the main beam (pipe) at the second stage of the construction with the inclusion of a reinforced concrete slab in the work.

σn ² = 2020 kg / cm ² - voltage in the lower fiber of the pipe.

σv ² = 360 kg / cm ² - voltage in the upper fiber of the pipe.

The total voltage in the lower fiber:

σn ² = 2565 kg / cm ² .

Total stresses in the upper fiber:

σ in ² = 781 kg / cm ² .

The calculated stress in the concrete slab 15 in the second stage:

σbet = 59.9 kg / cm ² .

The calculated stress in the longitudinal reinforcement of the plate 15 in the second stage:

σrs = 556.3 kg / cm ² .

The total deflection of the main beams of the superstructure was:

f = 3.5 cm.

Thus, the proposed method of construction of the bridge span allows to obtain the following advantages:

1. The use of a half-pipe between the beams allows you to achieve the following: under the influence of local load, a half-pipe with monolithic reinforced concrete works like an arch for compression. Under the action of the total load, part of the concrete in the places of the half-pipe fastening to the main beams is in the stretched zone. In this case, the half-pipe plays the role of external tensile reinforcement, helping concrete work.

2. Horizontal strands with nuts that fix the contour increase the reliability of the span, as they can be used to control the stress-strain state of the beams (to increase the stability of the beam, reduce tensile stresses in the lower fibers).

3. As a result of the rational distribution of concrete and the inclusion of the combined cross-section of the entire area of the reinforced concrete slab (in accordance with the diagrams of normal stresses), the span's work efficiency on bending under the influence of a common load increases, the mass, metal consumption decreases, and the crack resistance of the roadway plate increases.

4. A monolithic slab, consisting of two parts, increases the bearing capacity of the main beams at the first stage of loading the span and accelerates the process of erecting the span, because after each installation, a technician can move through each mounting block.

5. The absence of longitudinal seams of monolithic beams and the use of a monolithic plate allows to increase the fatigue strength and durability of the structure.

6. The development of the span structure for covering small spans (L = 15-21 m) is carried out taking into account the manufacture and installation of the span. The developed mounting blocks and their mounting methods with each other allow you to collect any dimensions of the span for a minimum time.

In general, the proposed method of erecting the flight structure of the bridge has certain technical and economic advantages compared to the known ones. Most clearly, the advantages of tubular spans are manifested in inaccessible places and in off-road conditions. Then the cost of work is reduced by 70% compared with typical reinforced concrete spans.

Claims (3)

1. A method of erecting a bridge span by mounting a metal part and then applying a reinforced concrete part to it, characterized in that the metal part is mounted of at least two mounting blocks, each of which consists of two metal tubular main beams located at a distance from each other, equal to the diameter of the tubular beam, and interconnected by an arched sheath, which is preliminarily made from a half-pipe having a diameter equal to the diameter of the tubular beam, and fixed along kam of the main beams of connecting arcuate elements, then, inside each main beam, strands are installed, and in each arched sheath, cross-links are placed, which together with the strands are placed in a horizontal plane and dispersed along the length of the block, and connected together in a cross section, forming in the block uniform transverse connections, while stiffeners with a central hole are placed in the supporting sections inside each main beam, after which they are welded to the shafts perpendicular to the upper surface of the mounting block Tnom procedure stops made in the form of pins, then are compounds mounting blocks with each other by overlapping two arcuate connecting members to form the shell are arched in the form of half-tube having a diameter equal to the diameter of the pipe main beam, and a monolithic reinforced concrete part produced. 2. The method according to claim 1, characterized in that the metal tubular main beams and semi-tubes connecting them are also fastened to each other with the help of cords and transverse ties, respectively, with the cords and transverse ties set horizontally. 3. The method according to claim 1, characterized in that the monolithic reinforced concrete slab is formed of two layers, of which the lower layer, made of reinforced concrete or fiber concrete, is pre-laid on each mounting block, forming the module of the span from the last, and the upper one, made of reinforced concrete, laid on the entire width of the span.

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