SU109892A2 - The method of artificial compression of concrete in massive base plates - Google Patents

Description

BASIC Auth. St. No. 100179 describes a method of artificially compressing concrete in massive foundation slabs of structures erected on compressible soils, in which the reinforcement of the stretched zone is embedded in the structure and, prior to laying in the STofi zone, the concrete is stretched by its own weight of the structure or loads on it, in order to provide the required tensile stress of the reinforcement, the base plate is divided by temporary seams into eccentrically loaded elements, the sediment of which is accompanied by turning to a certain ktnogo position.

The disadvantage of this method is that the use of full stretch tension reinforcement to compress the foundation slab depends on the elastic deformations of the base, which limits both the rotation of the tension blocks and the elongation of the reinforcement and does not make it possible to fully use the strength of steel. married.

In the described method, this disadvantage is eliminated. This is achieved by using prestressed reinforced concrete elements instead of steel reinforcement.

FIG. 1-3 depicts an exemplary embodiment of the reduction of concrete in a massive base plate, and in FIG. 1 shows the first stage of works; FIG. 2 is a complete view of the structure.

According to the invention, first of all, a base plate is made dissected by a temporary suture / onto loadable elements 2, the sediment of which is accompanied by turning to a certain design position. Then prestressed reinforced concrete elements 3 are laid in the form of rectangular, T-shaped or other cross-section beams and the seam between the blocks is sealed.

These elements can be made with the use of high-strength steel wire (7 mm) or reinforcement of a periodic profile from 25GS steel or from steels of other higher grades.

The above prestressed elements (beams) 3 are made using high strength concrete, the compressive stress of which can be increased to 150-250 kg / cm or more. The compressive stress of the concrete is assigned depending on the intensity of tensile stresses expected subsequently. At the same time, the stresses in the reinforcement of these elements can be brought to very large values that are not achievable in conventional reinforced concrete structures. The fastening of the ends of prestressed reinforced concrete elements 3 is carried out by arranging at the ends of the surface roughness in the form of fines or by releases from the ends of the reinforcement elements, the profile of which ensures the reliability of embedding the ends of the elements 3.

Later, gradually increasing the height of the side walls 4, they cause stretching in elements 3 with simultaneous compression in the lower part of the foundations.

In this case, positive (compressive) stresses can be stored in the prestressed elements, since the magnitude of the resulting tensile force, determined by calculation, can be assigned

less than a previously caused compressive force.

FIG. Figure 3 shows the design scheme of an artificially crimped base plate with a clamp, with the dotted line 5 indicating the resulting stresses on the ground without compression, and the continuous 6-voltage line during the reduction.

The use of prestressed reinforced concrete elements instead of steel reinforcement creates the possibility of the full use of the strength of high-strength steels with non-recurring crimping methods; better leveling of the stresses at the base, provided by increased rigidity of the tightening; passes of heavy vehicles and concrete laying cranes on horizontal overlapping elements; increase the pace of construction and reduce its time due to the use of prestressed elements, which do not need unification in subsequent blocking.

Subject invention

The method of artificial compression of concrete in massive base plates according to ed. St. No. 100179, characterized in that, in order to better utilize the strength of the reinforcing steel, to compress the structure, prestressed concrete elements are used instead of steel reinforcement.

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