RU130611U1 - STRUCTURE FOR STRENGTHENING BEAM BRIDGES WITH DOUBLE SUPPORT PARTS - Google Patents

Abstract

A design for reinforcing beam bridges with double supporting parts, including a support with supporting parts on which split spans in the form of beams are laid, and a monochromatic section between the beams, characterized in that each beam is rigidly connected to the support by means of fixed vertical strands passed through through channels in the beam, support and supporting parts.

Description

The utility model relates to bridge construction and can be used to strengthen existing spans or build new bridges, and can also be used in construction to strengthen the beams of floors of buildings and structures.

A known design for reinforcing beam bridges, including a support with supporting parts on which split spans in the form of beams are laid, and a monolithic section between the beams (see, for example, V.P. Eremeev, Strengthening reinforced concrete beam span road bridges. // Roads, - M: Informavtodor, 1987, No. 2, p.21, fig.10a). In this design, the split system is continuous.

The disadvantage of this design is the lack of rigidity of the bridge.

The utility model is based on the task of improving the design by increasing stiffness and redistributing the internal forces along the span of the bridge in connection with the introduction of additional fixed vertical cords.

The problem is solved in that in the design for reinforcing beam bridges with double supporting parts, including a support with supporting parts on which split spans in the form of beams are laid, and a monolithic section between the beams, each beam is rigidly connected to the support by means of fixed vertical braces, passed through the through channels in the beam, support and supporting parts.

Since in the design each beam is rigidly connected with the support by means of fixed vertical strands passed through the through channels in the beam, support and supporting parts, stiffness and redistribution of internal forces along the bridge span are ensured.

In Fig.1 shows a design for reinforcing beam bridges with dual supporting parts, side view, in Fig.2 - section aa in Fig.1; in Fig. 3, the influence lines of bending moments in a continuous beam are plotted, in Fig. 4, the influence lines of bending moments in a continuous beam with double supporting parts are plotted.

The design with double supporting parts consists of a monolithic section 1, of fixed vertical cords 2, passed through the through channels 3 in the span 4 in the form of beams, through the supporting parts 5 and through the body of the supports 6. The upper and lower ends of the cords are rigidly fixed and fixed in span 4 in the form of beams and the body of the supports 6.

In Fig. 3, Fig. 4, the analytical lines of the influence of bending moments in continuous and continuous beams with double supporting parts are constructed by the analytical method.

After monopolizing the supporting sections 1 - span 4 in the form of beams becomes continuous. By introducing fixed vertical strands 2 into the through channels 3 through the span 4 in the form of beams, through the supporting parts 5 and through the body of the supports 6, the design scheme changes, which requires an appropriate approach to the calculation. So a three-span split bridge after entering vertical cords turns into a five-span continuous. This design scheme is a multi-span continuous beam with double supporting parts.

Installation of the structure with dual supporting parts is carried out in the following order.

In the span 4 at the ends of the beams, the reinforcing bars are exposed, the reinforcing rods of adjacent beams of adjacent spans are joined together on the roadway plate, the supporting sections are monolithic 1. The through channels 3 are made with special channel formers (drilling machines) through the span 4 in the form of beams, supporting parts 5 and the body of the supports 6. The diameter of the through channels 3 is assigned from the calculations. Set fixed vertical strands 2, preferably prestressed, in these channels 3, so as to provide structural rigidity. In this case, the upper part of the strand 2 is fixed in the span 4 in the form of beams, and the lower part is in the body of the supports 6. Then monolithic and sealing of the through channels 3 are carried out.

In the proposed design, the reinforcing effect is achieved by changing the stiffness of the bridge and the appearance of supporting bending moments during the joint work of the span and supports for temporary loads. The values of bending moments in the middle of the spans for beam bridges are significantly reduced to 35%, the value of the dynamic coefficient decreases, which indicates an increase in the bearing capacity of the reinforced concrete span of the bridge.

The redistribution of internal forces along the span length is confirmed by the calculation below using the influence line method for specific parameters (dimensions in Fig. 3 and Fig. 4 in mm).

The areas of the corresponding lines of influence are:

W ₁ = 88.46 m ² ; W ₃ = 70.0 m ² ; _∑ W ₁ + W ₂ = 97.38 m ² ; W ₂ = 8.82 m ² . W ₄ = 55.0 m ² ; W ₅ = 69.84 m ² . W ₁ '= 63.18 m ² ; ∑ W ₃ + W ₄ = 125.0 m ² ; W ₃ '= 88.0 m ² ; W ₄ '= 77.22 m ² ; W ₅ '= 43.37 m ² ;

Comparison of M _n , M ₁ , M _K in%:

1.M _{n ∑} W ₁ + W ₂ and W ₁ '97.38> 63.18

35% reduction in bending moment in section "n";

2.M ₁ ∑ W ₃ + W ₄ and W ₃ '125.0> 88.0

30% reduction in bending moment in section "1";

3. ΣW M _to W ₅ and ₅ '69.84> 43.47

The decrease in bending moment in the section "K" by 35%,

where W _i - the area of the lines of influence under load;

M _i - bending moment in the corresponding sections;

i is the position of the sections.

The proposed design with dual supporting parts can be used to strengthen the beam (split, continuous and cantilever) and frame spans of bridges, both reinforced concrete and steel, and can also be used to strengthen the floor beams of buildings and structures.

Claims (1)

A design for reinforcing beam bridges with double supporting parts, including a support with supporting parts on which split spans in the form of beams are laid, and a monochromatic section between the beams, characterized in that each beam is rigidly connected to the support by means of fixed vertical strands passed through through channels in the beam, support and supporting parts.

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