RU93819U1 - COMBINED METAL SPAN STRUCTURE OF A BRIDGE - Google Patents

Abstract

 The metal girder bridge span with continuous main beams for railway load of two spatial mounting blocks, placed one on top of the other and combined as a whole, is equipped with horizontal connections, characterized in that it is also designed to pass vehicles, the inner beam transfers the load to the longitudinal beams of the lower of the orthotropic plate of the outer beam only at four points through the bearing device, the main beams are connected by horizontal ties in the upper zone pivotally and at one level, the rails are directly attached to the upper orthotropic plate of the inner main beam.

Description

The device relates to the field of bridge construction and can be used to block the navigable span of a restored railway bridge.

The prior art various prefabricated metal spans for blocking navigable (over 50 m) spans of railway bridges. [one]

The main disadvantage of these devices is their own weight (more than 140 tons), as a result of which there are no cranes of the corresponding lifting capacity for their installation. Basically, it is assumed a longitudinal slide of these spans with the device of intermediate supports or the use of an outback length from 0.5 to 0.75 span lengths, which increases labor costs.

The closest in technical essence to the claimed device is selected as a prototype metal girder bridge span with solid main beams under the railway load. [2] This is a span of two spatial blocks mounted one on top of the other. Each block consists of two main beams of a continuous I-section, combined by horizontal and vertical bonds into a rigid spatial system. The bridge beam is laid directly on the belts of the main farms.

The disadvantages of the known device are:

the support of the upper block to the lower along the entire length, which leads to an unfavorable distribution of forces, as a result of an excessive consumption of metal;

large construction height, which makes it difficult, if necessary, to pair with other spans of the bridge;

laying a bridge beam significantly increases labor costs.

The objectives of the proposed device is the overlap of the navigable span, reducing material consumption, labor costs and the implementation of the method of longitudinal sliding of the span with an outback of 0.25 to 0.5 m.

The device of the proposed span is illustrated by drawings: in Fig. 1, a facade is shown, in Fig. 2 is a plan, in Fig. 3 is a cross-section, in Fig. 4 is a diagram of a slide and installation of a span.

A metal span with riding on top to pass railway and road loads and consists of a spatial block of the inner loop 1 mounted on the spatial block of the outer loop 2, pivotally connected in the upper zone by horizontal ties 3 at the same level. In this case, the inner beam 1 transfers the load to the longitudinal beams 5 of the lower orthotropic plate 6 of the outer beam 2 only at four points through the supporting device 4. Thus, the inner beam 1 in a static scheme is a continuous three-span beam, which increases its rigidity, and in the outer main beam 2 decreases the bending moment. This provides a rational distribution of loads and a decrease in metal consumption in the whole span.

The optimal distance between the supporting devices 4 is: in the middle between the second and third - 0.4-0.6 length of the span; between the first and second, third and fourth - 0.2-0.3 lengths.

The outer beam 2 of an inverted U-shaped section consists of side walls 7 supported by vertical and horizontal stiffeners, a lower orthotropic plate 6 with longitudinal beams of the T-section 5.

The box-shaped inner beam 1 consists of side walls 8, a lower shelf 9, reinforced with stiffeners, an upper orthotropic plate 10, which has transverse beams of the T-section 11. Beams 11 also take longitudinal loads from horizontal ties 3 in addition to transverse loads.

Horizontal connections 3 in the plan consist of braces 12 and racks 13 of tubular section. They pivotally connect the main beams 1 and 2 in the upper zone and at the same level, prevent them from being displaced relative to each other along the axis of the bridge, as well as the deplanation of the section of the beam 1. Devices 14 providing swivel joints of the connections 3 are located on specially provided supporting tables 15 of the main beams which simultaneously act as horizontal stiffeners.

The rails 16 are directly attached to the upper orthotropic plate 10 of the inner main beam 1. On it is also a driveway plate for vehicles 17. The driveway plates for vehicles 18 are pivotally connected to the main beams 1, 2, and with the beam 1 through a vertical strut 19 of tubular section. The devices 20 are located on the supporting tables 15 of the beam 1. These connections and devices 20 do not allow inclusion in the joint work with the main beams of the plates 18.

For pedestrians, sidewalk consoles 21 are provided, and for inspection and maintenance of the structure, flooring 22.

To implement the longitudinal slide, the beams 1, 2 are fastened along the length, while the outback 23 is mounted to the outer beam 2, and the inner 1 serves as a counterweight. To create a margin of stability, the inner beam is loaded. Then push the outer beam 2 into the span. The beams are unfastened and the outer 1 is pushed along the inner 1. Using ties 3, the beams are fastened and the span is lowered to the design position.

Using the proposed span in comparison with existing ones will allow:

1. To reduce the labor costs for laying the bridge and by implementing the method of longitudinal slide without the use of a large length advance counter and intermediate supports.

2. Reduce the intensity of the structure.

3. To pass the rail and road transport.

Claims (1)

The metal girder bridge span with continuous main beams for railway load of two spatial mounting blocks, placed one on top of the other and combined as a whole, is equipped with horizontal connections, characterized in that it is also designed to pass vehicles, the inner beam transfers the load to the longitudinal beams of the lower of the orthotropic plate of the outer beam only at four points through the supporting device, the main beams are connected by horizontal ties in the upper belt articulated and at one level, the rails are directly attached to the upper orthotropic plate of the inner main beam.