RU2655457C1 - Plate foundation under tank - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to construction and is used in the construction of slab foundations for vertical steel cylindrical tanks for liquids, including oil and petroleum products, on natural soils. Slab foundation for the reservoir consists of a solid reinforced concrete slab and a compensating pad of variable thickness from an easily compressed material between the slab and the ground base in the peripheral zone. Precipitation and deflections of the foundation slab are equalized by decreasing the rigidity of the subsoil base by stacking the damping liners of the calculated thickness in the peripheral zones.

EFFECT: technical result consists of increasing the service life and improving the performance of the tank by reducing the bottoms of the tanks, reducing the internal forces in the foundation plate and, as a consequence, the material consumption of the foundation while maintaining the simplicity and manufacturability of the production of slab foundations.

1 cl, 2 dwg

Description

The invention relates to the construction and is used in the construction of slab foundations for vertical steel cylindrical tanks for liquids, including oil and petroleum products, on natural soil bases.

The foundation consists of a foundation slab and compensating gaskets of variable thickness from an easily compressible material between the slab and the soil base, which reduces the rigidity of the soil base in the direction from the center to the edges of the plate.

The well-known foundation of cylindrical tanks in the form of a continuous reinforced concrete slab [1]. However, in the indicated foundation, the central parts of the bottom undergo the greatest precipitation and deflection [2]. At the same time, the operation of the tank is complicated: a complete drainage of oil products is not provided, produced water accumulates, which often leads to accelerated corrosion of the metal and possible rupture of the bottom. Also, the unevenness of the sediment of the center and the edges of the slab foundation may exceed the permissible standard values [3].

The base of a cylindrical tank is known, consisting of a layer-by-layer compacted soil cushion of variable thickness, depending on the compressibility of the base, reinforced with layers of geogrid / geotextile with rigid ring elements for their tension [4]. The technical result of the invention is to align the vertical deformations of the bottom of the tank by increasing the rigidity of the base of the Central zone. The disadvantage of this invention is the complication of the technology for the production of works, an increase in the volume of earthwork, a significant expenditure of expensive materials on a pillow reinforcement device.

A well-known foundation of the tank, including a round base plate located on a soil cushion made in the form of a truncated cone and located in a cone-shaped recess of the base [5]. The technical result of this invention is to reduce the deflections of the bottom of the tank due to the device of soil preparation of variable stiffness. The disadvantage of this foundation is the increase in the volume of earthwork, the need to develop an excavation pit of complex shape, significant transport, material and labor costs for the installation of soil pillows.

Closest to the invention in technical essence is a plate-ribbed foundation of controlled exposure with a soil base. [6] The foundation consists of rigid tapes oriented along the force axes of the building and thin plates forming the span. A damping pad in the form of a porous easily compressible material is provided between the plate part and the soil base, which ensures the later inclusion in the work of the span zone. However, the scope of the invention is limited to foundations for structures with a frame or wall design.

The objective of the invention is to reduce the internal forces and deflections of the foundation slab by leveling the stiffness of the soil base at the base of the foundation.

The technical result of the invention is:

- to increase the service life and improve the performance of the tank by reducing the deflection of the bottom of the tanks;

- in reducing the material consumption of the foundation by reducing internal efforts in the foundation plate;

- in maintaining the simplicity and manufacturability of the production of slab foundations.

The problem is solved by the installation of compensating gaskets of easily compressible materials with a thickness increasing in the direction from the center to the edge of the plate.

The invention is illustrated by drawings, where in FIG. 1 is a schematic diagram of the work of a slab foundation in the absence (left side) and presence (right side) of the compensating layer. In FIG. 2 shows a general view in orthogonal projection.

The slab foundation for the tank consists of a continuous reinforced concrete slab (1) and compensating gaskets of variable thickness from an easily compressible material (2) between the slab and a natural subgrade (3).

It is known that when loading a round flexible plate with a uniform load, the center gives a draft 1.24-1.57 times larger than the edges [7]. Accordingly, the stiffness coefficient of the soil base, determined according to the Winkler-Fuss contact model, reaches a maximum value (“short springs”) at the edge of the slab and gradually decreases to the center to a minimum value (“long springs”). As a result, the uniformly loaded plate in the Winkler-Fuss calculation model relies on supports of variable stiffness, which determines a significant deflection ƒ ₁ and the appearance of significant bending moments M ₁ in the plate itself.

The invention proposes to insert gaskets (2) between a continuous reinforced concrete slab (1) and a natural soil base (3) to compensate for the uneven compressibility of the soil base. The thickness of the gaskets (2) is selected based on the solution to the problem of leveling the stiffness coefficients of the soil base. Gaskets are proposed to be made of plate easily compressible materials based on polystyrene foam with a thickness of 20-100 mm. As a result, the deflection ƒ ₂ and the internal forces M ₂ in the foundation plate are reduced

The novelty of the invention consists in equalizing the sediments and deflections of the foundation slab by reducing the stiffness of the soil base in the peripheral zones by laying compensating gaskets of the estimated thickness, which eliminates the construction of complex structural elements and minimizes material and labor costs.

The device of the slab foundation under the tank is as follows. A foundation pit is being developed to the planning mark of the natural foundation. On a natural ground foundation (3), compensating pads of the estimated thickness (2) are laid and fastened. In order to avoid damage to the gaskets (2) during subsequent construction work, a protective screed of lean concrete is made on them. The formwork is exposed and the reinforced concrete slab is reinforced (1). Concreting of a continuous reinforced concrete slab (1) and care of concrete during hardening are performed.

Information sources

1. Tetior A.N. Foundations: a textbook for students of institutions of higher prof. education / A.N. Tetior. - M.: Publishing Center "Academy", 2010. - 400 p.

2. Dimov L.A. Deformed state of slab foundations of reservoirs for oil and oil products. / L.Ya Dimov // Geotechnics. - 2015. - No. 1 - S. 9

3. SP 22.13330.2011 Foundations of buildings and structures. Updated edition of SNiP 2.02.01-83 * / Ministry of Regional Development of Russia. M .: OJSC "TsPP", 2011.

4. Pat. 2437988 Russian Federation, IPC E02D 27/38. The base of the cylindrical tank / Yeshenko O.Yu., Volik D.V .; Applicant and patent holder Kuban State Agrarian University (RU). - No. 2010119896; declared 05/18/2010; publ. 12/27/2011, Bull. Number 36.

5. Pat. 2439248 Russian Federation, IPC E02D 27/38. The foundation of the reservoir on a weak base / Yeshenko O.Y .; Applicant and patent holder Kuban State Agrarian University (RU). - No. 2010119894; declared 05/18/2010; publ. 01/10/2012, Bull. No. 1.

6. Pat. 2561441 Russian Federation, IPC E02D 27/12. Plate-ribbed foundation shallow. / Pronosin Y.A., Kiselev N.Yu .; FSBEI HPE Tyumen State University of Architecture and Civil Engineering (RU).

7. Gorbunov-Posadov M.I., Malikova T.A., Solomin V.I. Calculation of structures on an elastic foundation. - M .: Stroyizdat, 1984. - 679 p.

Claims (1)

A slab foundation for a tank consisting of a continuous reinforced concrete slab and compensating gaskets of variable thickness from an easily compressible material between the slab and the soil base in the peripheral zone, characterized in that the precipitation and deflection of the foundation slab are aligned by reducing the stiffness of the soil base by laying damping pads of the calculated thickness in peripheral zones.

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