RU64646U1 - PLATE-RIBE SPAN STRUCTURE WITH HORIZONTAL DIAPHRAGMS IN SUPPORT SECTIONS - Google Patents

Abstract

The utility model relates to construction and can be used in the construction of slab-ribbed beam spans. The objectives of the utility model are to increase the reliability and carrying capacity, reducing the material consumption of beam spans. A plate-ribbed superstructure with a ride on top (Figs. 1, 2) is composed of T-blocks 2 mounted on the supporting parts 1, connected to each other in a single structure along the roadway plate 3 by monopolizing the longitudinal joints 4 along the entire length of the span and by means of the device supporting sections at the level of the lower belt of horizontal diaphragms 5 of monolithic (precast) reinforced concrete. Fig. 2.

Description

The utility model relates to construction and can be used in the construction of slab-ribbed beam spans.

Known design of plate-ribbed spans with riding on top, made up of T-beams, interconnected by mounting joints in the plate of the carriageway and in the transverse beams (diaphragms), only in the plate of the carriageway and only in the diaphragms. (E.E. Gibshman, N.Ya. Kalmykov, N.I. Polivanov, BC Kirillov. Bridges and structures on the roads. Scientific and technical publishing house of the Ministry of Road Transport and Highways of the RSFSR. M., 1961, p. 305-314 )

The experience of building spans with joints only in the diaphragms indicated a significant drawback of these structures associated with the work of the carriageway slab according to the cantilever scheme, in which the distances between the main beams, determining the size of the cantilevers, are limited to 1.5-1.6 m, while the presence of often located diaphragms complicated manufacturing of beams.

The desire to maximize the monolithic span by combining the blocks between each other both in diaphragms and on the slab of the carriageway led to a significant increase in labor costs for the manufacture of blocks in comparison with the manufacture of spans from monolithic reinforced concrete on the scaffolds.

The closest design to the proposed technical essence and the achieved effect is a diaphragm-free span made up of blocks united by a longitudinal seam of monolithic plate of the carriageway along the entire span. (Soyuzdorproekt. Typical structures, products and units of buildings and structures: series 3.503.1-73. Span structures without diaphragms made of reinforced concrete beams of T-section with non-tensioning reinforcement, 1992; series 3.503.1-81. Span structures prefabricated reinforced concrete 12, 15 lengths , 18, 24, 33 m from I-section beams with prestressing reinforcement, 1994).

A disadvantage of the known construction is that the multi-rib span structure of the open profile, being a thin-walled plate-rib system installed by ribs on the supporting parts, is subject to torsion during eccentric loading with a temporary load, which creates obstacles to the free distortion (deplanation) of the transverse

sections with the appearance of self-balanced normal stresses and horizontal reactions. As a result, in the areas of support of the beams under the influence of horizontal reactive forces, stress concentrations exceed the ultimate and lead to the destruction of concrete support zones, support anchors and to the disruption of the functioning of the support devices.

The objective of the utility model is to increase reliability and load capacity, reduce the material consumption of plate-ribbed beam spans.

The specified technical result is achieved by the fact that the plate-ribbed span with riding on top, including T-beams installed on the supporting parts, combined with each other in a single structure along the carriageway plate by monopolizing the longitudinal joints along the entire length of the span, is equipped on supporting sections in the level of the lower belt beams with rigid horizontal diaphragms made of monolithic (precast) reinforced concrete, forming together with the beams a closed unchanged contour.

These differences are significant in a number of ways:

1. Based on the layout, the structures under consideration are composed of separate prefabricated blocks mounted on supports. After combining the blocks with each other, both the analog and the prototype become multi-ribbed systems with an open cross-section contour, while the claimed design receives short sections of a closed, unchanged contour (in the remaining sections, an open contour in the supporting zones), which absorbs the deplanations of the reference sections.

2. Based on the increase in carrying capacity, the claimed design has a greater bearing capacity due to the redistribution of normal stresses in the span sections. In this case, the normal stresses from the bimoment in the reference sections of the known solutions are considered to be zero, and in the middle of the span - maximum. In the claimed design, they have maximum values in the reference sections and significantly reduced in sections of the middle span.

3. On the basis of increased reliability, support devices (support parts and their fastening) and support zones of the claimed design do not experience impacts from the deplanation of support sections (it is extinguished by the support section of the closed loop), the support devices and bearing zones are operated in the modes provided by the design without destructive effects .

Thus, the claimed span has a combination of features that distinguish it from the prototype and known

solutions and allowing to achieve increased reliability, increased load capacity, reduced material consumption of plate-ribbed spans.

Figure 1 shows a cross section of a diaphragm-free plate-ribbed span with horizontal diaphragms in supporting sections; view aa, bb in figure 2; figure 2 is a view along BB in figure 1.

A plate-ribbed superstructure with a ride on top (Fig. 1,2) is composed of T-blocks 2 mounted on the supporting parts 1, united into a single structure along the plate of the carriageway 3 by monopolizing the longitudinal joints 4 along the entire length of the span and by means of the device supporting sections at the level of the lower belt of horizontal diaphragms 5 of monolithic (precast) reinforced concrete.

The horizontal diaphragms 5, together with the walls and the slab, form sections in the supporting zones of the span with a closed unchanged contour that absorbs the deplanations of the reference sections. As a result of this, the work of the span is carried out according to the scheme of the beam system with deplanation terminations at the ends, which leads to the redistribution of normal stresses in the sections from the bimoments with a decrease in the middle of the span. In addition, the device of rigid horizontal diaphragms makes it possible to isolate fixed support parts and their fixations from the need to act as obstacles to the perception of deplanations arising from constrained torsion.

The proposed design involves the use of beams of typical non-diaphragm spans. The device of horizontal diaphragms at the level of the lower belt of beams in the support zone will not require significant material and labor costs.

The proposed span has a reserve increase in carrying capacity, differs little from the known structures in terms of complexity and exceeds them in terms of reliability and durability.

Claims (1)

A plate-ribbed superstructure with riding on top, including T-beams installed on the supporting parts, united among themselves in a single structure along the carriageway plate by monoling longitudinal joints along the entire length of the span, characterized in that it is equipped with rigid horizontal sections on supporting sections diaphragms made of monolithic (precast) reinforced concrete, forming a closed unchanged contour in the supporting zone.