RU2056492C1 - Structural member - Google Patents

Abstract

FIELD: civil engineering. SUBSTANCE: structural member has concrete, bar-type and lengthwise positioned spiral reinforcement. The reinforcement is connected to support plates. Bar-type reinforcement is placed inside spiral reinforcement. Spiral reinforcement is installed along perimeter of the structural member. Total area of overlapping the spirals is S = (0,1-0,2)S •K,, where S is total area of overlapping two adjacent spirals, S is cross- section of concrete placed inside one spiral. Empirical coefficient K = 0.9 - 1.0 takes into account effect of angular lengthwise reinforcing bars. Closed zones are formed inside the structural member. Bar-type reinforcement is placed in the corners of the structural member. Besides spiral reinforcement is installed along perimeter of the structural member to enable reinforcement to make contacts to one another, and to form internal and external closed zones. EFFECT: high seismic stability. 2 cl, 2 dwg

Description

 The invention relates to the construction and can be used both in the construction of fortifications, bomb shelters, and frame buildings erected in seismic regions of the country.

Known building element containing embedded parts in the form of profiles installed with the formation of a closed metal circuit filled with concrete monolithic [1]
Also known is a column-type building element containing concrete, longitudinal steel rods and spirals of indirect reinforcement, with the turns of adjacent spirals located in the same plane partially overlapping, and spirals located perpendicular to them are installed in the zones of their alignment [2]
The closest in technical essence to the achieved result to the invention is a building element containing concrete, rod and longitudinally located spiral reinforcement connected to the base plates, and the rod reinforcement is placed inside the corner spiral reinforcement [3]
The disadvantage of this design of the building element is the fact that under intense dynamic loads that occur during earthquakes and explosions, there is a loss of stability of the longitudinal linear reinforcement, especially for extended building structures such as columns, which entails its destruction.

 The basis of the invention is the task of increasing the bearing capacity of structures and buildings operating under intense seismic impact without brittle fracture of the load-bearing elements of the reinforcing cage, which increases the reliability and safety of buildings and structures, and hence earthquake resistance while reducing metal consumption and reducing the amount of welding work during installation.

The essence of the invention lies in the fact that in a building element containing concrete, rod and longitudinally located spiral reinforcement connected to base plates, and rod reinforcement is placed inside the corner spiral reinforcement, spiral reinforcement is installed around the perimeter of the building element with overlapping adjacent spirals with a total overlap area S _per. = (0.1-0.2) S _sp. · K, where S _per. total overlap area of two adjacent spirals;
S _sp. the cross-sectional area of concrete placed inside one spiral reinforcement;
K 0.9-1.0 empirical coefficient taking into account the influence of angular longitudinal reinforcing bars; with the formation of closed zones inside the building element, at the corners of which is located rod reinforcement.

 In addition, spiral reinforcement is installed around the perimeter of the building element with the possibility of contacting each other and the formation of external and internal closed zones.

 Figure 1 shows a building element, a General view; figure 2 section aa in figure 1.

The building element consists of two base plates 1, installed at a certain distance from each other, longitudinal spiral reinforcement 2, perpendicularly fixed around the perimeter to the inner surface of the base plates, longitudinal reinforcing rods 3 installed inside the corner spiral reinforcement and also fixed to the inner surface of the base plates and concrete 4. Concrete 4 forms two types of closed areas of zones inside the body of a reinforced concrete building element: these are peripheral zones 5 inside spiral reinforcement p 2 and the reinforcement bars 3 without them as well as a central zone 6 between the two spiral reinforcement (sm.fig.2). Spiral fittings 2 can be installed with the overlapping of two adjacent spirals with a total overlapping area of two adjacent spirals equal to S _per. (0.1-0.2) S _sp. · K and without overlapping two adjacent spirals.

 Assembly of the building element is carried out in a special formwork device or conductor-pencil case (not shown in the drawings) as follows.

 First, on the periphery of the inner surface of the base plates 1 mark the location of the fastening of the spiral reinforcement 2 with or without overlapping two adjacent spirals. Then, longitudinal reinforcing bars 3 are fixed to the inner surface of one of the base plates 1 at the location of the angular spiral reinforcing bars 2, angular spiral reinforcing bars are put on them and fixed to the inner surface of one of the base plates, where the rods are already fixed. Then, along the perimeter of the base plate, the remaining spiral reinforcement is installed taking into account the overlap of adjacent spirals or without it, which are also fixed to the inner surface of the base plate. Then the free ends of the longitudinal reinforcing rods 3 and spiral reinforcement 2 are fixed to the inner surface of the second base plate. The reinforcing frame of the building element thus assembled is placed in a special formwork device or conductor-pencil case, where it is poured with concrete. After building strength, the building element is redistributed and sent to the finished goods warehouse.

 Works building element as part of a structure or building as follows.

 In earthquakes or explosions, structures of structures and buildings are subjected to repeated effects of forces corresponding to dynamically applied alternating loads of a random direction and magnitude. Under the influence of calculated and large-scale forces, transverse and longitudinal cracks form in reinforced concrete elements, which sharply reduce the stiffness and strength of the sections, which can cause brittle destruction of elements with catastrophic consequences for people with the next exposure.

The formation of cracks in reinforced concrete structures occurs as a result of the action of the main tensile stresses. Traditional longitudinally and transversely oriented reinforcement with a random direction of the load can lead to early cracking along dangerous sections. Premature cracking in this technical solution is prevented by turns of spiral reinforcement 2. This allows you to effectively resist tensile stresses of arbitrary orientation. Moreover, the ultimate deformability is ζ _before. (12-15) · 10 ^-3 , which is 5-8 times higher than the deformability of existing building elements.

 Under the action of compressive loads, the reinforcing bars 3 are protected from loss of stability by peripheral "zones" 5 inside the spiral reinforcement 2. The reinforcing bars 3 are not exposed to concrete 4. The location of the spiral reinforcement along the perimeter of the cross section of the building element with mutual overlap in turn creates a closed zone 6 in the center of the reinforced concrete element, for which the elements of all peripheral spirals play the role of a limiter of transverse deformations. This is especially important with eccentric compression of the building element. High deformability of the claimed building element eliminates the brittle nature of its destruction, and the created closed zones 5 and 6 significantly delay the moment of loss of stability of the reinforcing bars, which increases the bearing capacity of the reinforcing cage of the building element under seismic impact.

 Using the proposed building element will increase the safety and reliability of buildings and structures during intense seismic impact and seismic impacts by 1.5-2.0 times, reduce the amount of welding work by 2.5-3.5 times, reduce the reinforcement coefficient, which leads to a reduction labor costs, energy saving, simplifying assembly technology.

Claims (2)

1. CONSTRUCTION ELEMENT containing concrete, rod and longitudinally arranged spiral reinforcement connected to the base plates, and the reinforcement is placed inside the corner spiral reinforcement, characterized in that the spiral reinforcement is installed around the perimeter of the building element with overlapping adjacent spirals with a total overlapping area S _{( p e p )} equal
S _{n e p} = (0,1 - 0,2) • S _{c n} • K,
where S _{p e r} - total area of overlap of two adjacent spirals;
S _{with p} is the cross-sectional area of concrete placed inside one spiral reinforcement;
K = 0.9 - 1.0 - an empirical coefficient that takes into account the influence of angular longitudinal reinforcing bars,
and the formation of closed zones inside the building element, at the corners of which is located rod reinforcement.  2. The element according to claim 1, characterized in that the spiral reinforcement is installed around the perimeter of the building element with the possibility of contacting each other and the formation of external and internal closed zones.

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