RU2291242C1 - Bridge structure - Google Patents

Abstract

FIELD: bridge building, particularly structural or constructional details of bridges.

SUBSTANCE: bridge structure comprises span assembly made of standardized members formed as panels with ribs or having box-like or U-shaped cross-sections. The span assembly is made as girder of single- or multi-span closed frame with V-shaped piers. The piers include a number of struts having constant thicknesses and creating inclined walls in transversal direction. Upper wall ends are provided with joint members connected to frame girder and extending at an angle of 30-60°. Lower wall ends are connected with each other and define support parts to install the span structure on high supports arranged in river over the highest water and ice drift level and provided with bearing parts. Lower wall ends may be connected directly to foundation to create non-thrust and trust structures correspondingly. Inclined thrust walls are provided with longitudinal depressions, which are symmetric with respect to longitudinal axis of bridge structure, wherein each inclined wall has at least 2 depressions. Double-hinged strut inserts are installed so that the strut inserts are spaced apart maximal distance. The strut inserts have design sections, which take full support (compression) pressure with taking into consideration lateral deflection. The strut inserts thickness is equal to that of V-shaped pier wall.

EFFECT: increased efficiency and service life of bridge structure, elimination of conditions, which cause bridge structure service life reduction, possibility to retain architectural form and to use standard members and joints, reduced material consumption and costs.

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Description

The invention relates to bridge construction and can be used in the construction of bridges and overpasses.

A reinforced concrete bridge structure with riding on top is known, intended for the construction of crossings, mainly through highways and navigable rivers, of a combined structure of unified elements in the form of a single or multi-span closed frame with inclined, at an angle of ~ 45 °, V-shaped supports, received for high the architectural expressiveness is the name "Running Doe" or "Bird" (analogue).

Bridge constructions of this type in our country began to be built in the seventies of the last century, and their number grew rapidly. They were also distinguished by high technical and economic indicators, and the crossings through the motorways, in addition, provided good visibility from the position of the driver; contributed to the reduction of accidents; finally put an end to the monotony on the roads. However, after 10-15 years of operation, it turned out that they were short-lived.

The disadvantages of the analogue are the low efficiency of the structure due to a shortage of the durability resource, which caused the formation of numerous cracks in the bearing elements of the frame and quickly led to their complete destruction. Bridge structures, in most cases, underwent premature rebuilding or major repairs.

The closest prototype in its essence and the achieved result are, for example, the following two bridge structures:

1) an overpass of frame construction, built on 209 km of the Moscow-Volgograd highway at the junction with the Tula-Ryazan highway near the city of Mikhailov, in 1969-1971;

2) a bridge across the shipping channel to them. Moscow in the village of Khlebnikovo.

Both structures were designed by the Soyuzdorproekt Institute, Moscow.

The overpass was built in the form of a single-span frame, which consisted of a crossbar of a plate-ribbed structure, two V-shaped supports made of a set of struts in the form of flat inclined walls of constant thickness along the facade and a variable expanding upwards in the transverse direction. The upper and lower ends of the struts have a rigid combination with the crossbar of the frame and the foundation.

The bridge over the Moscow Canal in the area of the village of Khlebnikovo, the span of which is made in the form of a multi-span frame with a cross-beam of a U-shaped cross section and also with V-shaped supports from struts with rigid nodal associations of the upper ones (with longitudinal ribs of a U-shaped crossbar) and lower ends between themselves, forming the supporting sections of the span, with the help of which it is hinged, without touching the sub-trusses, is located on the bridge supports.

The disadvantages of the prototypes, which are common for both examples, are the low efficiency of the design, associated with a lack of durability and loss of bearing capacity due to cracks in the concrete of the crossbar and struts, the disclosure of which, due to the interdependence of the bending deformations of the crossbar and struts, is constantly increasing and, in ultimately, reaches dangerous for construction values.

The elimination of these disadvantages by known methods, such as equalizing the cross-sections of the struts and the crossbar of the frame in the nodes of the union or reduce the span of the "bird wings" by increasing the contact angles of the upper ends of the struts to the crossbar (more than 60 °), leads to a decrease not only in architectural advantages, but and to reduce the span, cost overruns, the bulkiness of the structure, the loss of "unification" and the overall increase in the cost of construction.

It is known that the overpass on 209 km of the Moscow-Volgograd highway, long before the standard service life, exhausted its life and in the early 80s was converted to a conventional, beam type, according to the 2 × 24 m scheme, with an intermediate support on the dividing strip of the road .

For the same reason, the bridge over the Moscow Canal in the area of the village of Khlebnikovo is currently undergoing major repairs.

All this led to the fact that the construction of bridge structures of this type was “discontinued”, and the Running Doe disappeared on the motorways.

EFFECT: increased efficiency and durability of the combined construction of a bridge structure; elimination of the causes of the shortage of the resource of longevity; maintaining architectural expressiveness and enhancing their durability, "typing" of structural elements; decrease in material consumption and cost; rehabilitation and restoration of lost trust in these economical and original structures.

The specified technical result is achieved in that the bridge structure with riding on top, having a span of unified elements of a plate-ribbed, box-shaped or U-shaped section, made in the form of a crossbar of a single or multi-span closed frame with V-shaped supports from a set of struts of constant thickness along the facade, forming inclined walls in the transverse direction, the upper ends of which have rigid nodal associations with the crossbar of the frame, at an angle from 60 ° to 30 °, and the lower ones to each other, forming supporting sections for new spans to high, above levels of high water and ice drift, channel supports equipped with supporting parts, or directly with the foundation, creating accordingly an undivided and spacer structure, characterized in that the inclined strut walls are provided with longitudinal niches, which are asymmetric with respect to the longitudinal axis of the bridge structures, in an amount of at least 2 pieces on the wall, at the greatest possible distance from each other, install double-hinged struts-inserts with a design cross-section that ensures recovery riyatie full reference pressure (compression) with the buckling, the thickness of the strut inserts should be equal to the wall thickness of V-shaped supports.

The application of the proposed bridge structure allows us to realize the result of increasing the efficiency and durability of the structure by introducing into the V-shaped support at least 4 (two for each inclined wall) double-hinged struts-inserts, which, as the bends increase deformations in struts with rigid nodal joints, while not subjected to bending, take on pressure (compression) forces and, preventing the development of cracks, keep them in a state of very small opening, practically and without reducing the durability of the structure. At the same time, we can refer to many years of scientific experiments and observations, which indicate that reinforced concrete working in bending, including prestressed, does not exist without cracks (prof. L.I. Iosilevsky, MIIT, Moscow, Zhurnal. Transport Construction No. 11 , 2002, p. 13-17).

Accordingly, with the weakening of the influence of the bending moment, there is no need to increase the cross-section of struts, especially along the facade of the structure, and it becomes possible to "select" their thickness and the angle of contact with the crossbar of the frame according to aesthetic criteria.

Figure 1 shows a General view of a single-span bridge structure, spacer system.

Figure 2 is a transverse section I-I in the middle of the V-shaped support. The lower ends of the struts are rigidly combined with the foundation.

Figure 3 is a view along BB on the strut with a rigid nodal union.

Figure 4 - node A is the junction of the double-hinged strut-insert to the crossbar.

Figure 5 is a fragment of a General view of a multi-span bridge structure, an undisclosed system.

Figure 6 is a cross section of a U-shaped crossbar and a view of the strut wall.

Figure 7 - node support span on the channel support.

In Fig.8 is a General view of a single-span non-abutment bridge structure.

An example implementation.

The construction of the frame of the spacer bridge structure, consisting of a crossbar 1 and a V-shaped support 2, begins when the foundations 3 are ready, in which, for example, “wells” or “glasses” 4 are provided for installation in the design position and monoling struts 5, and in the alignment niches 6, sub-fermenters 7, for double-hinged struts-inserts 8, with hinges 9. Then, prefabricated blocks are installed on the scaffolds on top of the struts 5 or the corresponding elements of the crossbar 1 are concreted in the formwork, in which channels for tightening 10 and "windows" for monolithing the top are provided x ends of struts 5. The assembly of the remaining elements of the span corresponds to typical technological processes.

The implementation of the bridge structure of the non-support system, which, incidentally, is also applicable on highways as an alternative to the Running Doe viaducts, begins with the installation or concreting of the crossbar 1 of the span according to the readiness of the channel 11 or (for viaducts) of the extreme 3 supports, on top of which standard supporting parts and begin assembling on them from the supporting section 12, made in the form of a bar with reinforcing outlets and embedded parts of the type of "door hinge". By combining the “loops” with the pins, the struts 5 are deployed around them and, holding with the help of twists and supports in the design position, the lower ends of the struts and trusses 7 are monolithic under the hinges 9. Then the bolt 1. is mounted. It can be carried out in different ways - by assembling on the scaffolds, longitudinal slide or concreting in mobile formwork. At the same time, in the crossbar 1, niches or “windows” are foreseen for monopolizing with the upper ends of the struts 5, and in the niches 6, the sub-trusses 7 under the double-hinged struts-inserts 8 with hinges 9 simultaneously at a time. The installation of the puff 10 can be made as part of the crossbar 1 after monolithic, and in advance as a separate element at the upper ends of the struts 5.

The installation of the crossbar 1 of a single or multi-span frame is considered completed after the curing of the monolithic concrete, when all auxiliary devices can be removed: stretch marks, supports, scaffolds and formwork.

Claims (1)

A bridge structure with riding on top, having a span of unified elements of a plate-ribbed, box-shaped or U-shaped section, made in the form of a crossbar of a single or multi-span closed frame with V-shaped supports from a set of struts of constant thickness along the facade, forming inclined walls in transverse direction, the upper ends of which have nodal associations with the crossbar of the frame, at an angle from 60 ° to 30 °, and the lower ones are interconnected, forming supporting sections for setting the span to high, above the high of ice and ice drift, channel supports equipped with supporting parts, or directly with the foundation, creating accordingly non-abutting and spacer structures, characterized in that the inclined strut walls are provided with longitudinal niches, which are symmetrical about the longitudinal axis of the bridge structure, in an amount of at least 2 pieces on the wall, at the greatest possible distance from each other, install double-hinged struts-inserts with a design cross-section that ensures the perception of full reference pressure (compression), taking into account the longitudinal bending, while the thickness of the struts-inserts is assigned equal to the wall thickness of the V-shaped support.

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