RU2561441C1 - Slabby and finned shallow foundation - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to civil engineering and can be used at the construction of shallow foundations. The slabby and finned shallow foundation contains foundation fins buried in soil along strength axes of the building. In the span zone there is a thin continuous plate. Between the plate and the ground base a damping layer is provided. It is made of a slabby highly compressed material. The thickness of the damping layer is selected from the condition of transmission to the base ground through the foundation fins of pressure providing settling of these fins to the value equal to the thickness of the damping layer and corresponding to the design resistance of the named ground. With exhaustion of compression of the material of the damping layer the possibility of its crimping with the formation of the uniform foundation and the zone of compaction under it in strong surface layers of ground with the redistribution of force of its repulse from the span zone of the foundation on its fins is provided.

EFFECT: expansion of the scope of application and decrease of the material capacity of the foundation due to the more effective distribution of loads.

3 dwg

Description

The invention relates to the construction and is used in the construction of shallow foundations for buildings mainly of medium and high storeys on soil foundations, represented by the upper layer of dense soils, underlain by the thickness of weak water-saturated dusty clay soils.

The foundation consists of rigid tapes oriented along the power 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.

Known tape foundation shallow [Tetior A.N. Foundations: textbook. allowance for students. institutions of higher prof. education / A.N. Tetior. - M.: Publishing Center "Academy", 2010. - 400 p.]. However, the field of application of these foundations is limited by exceeding the stresses of the calculated resistance of the soil of the base and the redistribution of forces in ground structures with uneven precipitation.

The well-known shallow foundation in the form of a continuous reinforced concrete slab [Tetior A.N. Foundations: textbook. allowance for students. institutions of higher prof. education / A.N. Tetior. - M.: Publishing Center "Academy", 2010. - 400 p.]. However, in this foundation the strength characteristics of the soil are not fully used, and also such foundations often have increased precipitation due to the considerable depth of the compressible thickness and increased material consumption.

Known plate-pile foundation with damping gaskets of various thicknesses, due to the device of which a predetermined distribution of loads between individual piles and plate is achieved [Patent for invention No. 2301303. Plate-pile foundation. Authors: Lushnikov V.V., Orzhekhovsky Yu.R., Smetanin M.V., Yardyakov A.S. It is registered in the State Register of Inventions of the Russian Federation on 09.03.2005]. Known strip foundation with the installation of damping pads at angles in order to equalize contact stresses on the sole [Tetior A.N. Foundations: textbook. allowance for students. institutions of higher prof. education / A.N. Tetior. - M.: Publishing Center "Academy", 2010. - 400 p.]. The above design solutions borrowed the idea of a method of controlled load distribution between elements of the "foundation - soil base" system.

Closest to the invention in technical essence is the foundation in the form of rigid orthogonal ribbons united by flexible upward convex shells arranged on a curved surface [Patent for invention No. 2393297. Foundation. Authors: Pronosin Ya.A., Poroshin O.S., Melnikov R.V. Registered in the State Register of Inventions of the Russian Federation on April 29, 2009]. The disadvantage of this solution can be considered technological difficulties associated with the device of a curved surface, the occurrence of spacer forces in the tapes, as well as the possibility of cracks and a decrease in the durability of the shell due to its tensile work.

The purpose of the claimed invention is to

- in expanding the field of application of shallow foundations, arranged on a dense natural foundation of limited thickness, underlain by weak water-saturated clay soils.

- in reducing the material consumption of the foundation due to a more efficient distribution of loads between the tape and plate parts.

The problem is solved by the device in the span zone of the foundation of damping gaskets of easily compressible materials on a natural basis, providing a specified distribution of loads on the bottom of the foundation and the formation of controlled compaction zones in the soil mass. At the same time, it is proposed to select the thickness of the damping gaskets from the condition of transferring to the strip foundations the pressure corresponding to the calculated resistance of the foundation soil, before the span zone is included in the work.

The invention is illustrated by the drawings in FIG. 1-2.

In FIG. 1 shows a general view of the invention in orthogonal projection. The design consists of rigid orthogonal tapes 1 oriented along the force axes of the building, a thin plate in the passage zones 2, a damping pad 3 between the plate 2 and the natural base 4.

The foundation device is as follows. A foundation pit is being developed to the planning mark of the natural foundation. Dig trenches under the strip foundations. At the base of the span zone, damping pads made of highly compressible plate material are laid. The formwork is exposed and the foundation is reinforced. Concreting and concrete care during hardening is carried out.

The operation scheme of the foundation is shown in FIG. 2-3.

At the first stage of work (figure 2), the loads from the erected above-ground structures are transferred to the soil base mainly through the ribs of the slab foundation along the power axes due to the compression of the gaskets in the span zones. In this case, local compaction zones are formed under the ribs in strong surface layers.

At the second stage of work, after the ribs have been deposited by an amount equal to the thickness of the damping gaskets and the exhaustion of the "free-running" gaskets, the spans forming a single standard foundation are included in the work. At the same time, the depth of the compressible thickness for the proposed invention is reduced by 10-15% compared with a uniformly loaded base.

Thus, the advantages of the proposed foundation design are as follows:

1) reduction of the final value of sediment due to controlled uneven loading of the base;

2) reduction of the material consumption of the foundation structure due to the redistribution of efforts to repulse the soil from the span zones to the ribs and, as a result, the reduction of bending moments in the span;

3) maintaining the technological simplicity of the production of conventional slab and strip foundations;

4) the possibility of increasing the accuracy of evaluating the compressibility characteristics of the base under the strip foundations due to field tests with a flat stamp comparable to ribs.

Claims (1)

A shallow-ribbed foundation of shallow laying, containing foundation ribs buried in the ground along the force axes of the building, a thin continuous slab in the span and a damping pad between the slab and the ground base, which is made of highly compressible slab material, the thickness of which is selected from the condition of transferring the foundation to the ground through the foundation ribs of pressure, ensuring the settlement of these ribs by an amount equal to the thickness of the damping pad and corresponding to the calculated resistance of the said soil, with aniem compression material pads possible to crimp it with the formation of a unified foundation and seal them in areas under strong surface layers of soil to the redistribution of the efforts of his resistance to the transit area on the foundation of its edges.

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