RU2331738C1 - Foundation of piles and slabs - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention is attributed to construction and can be used during erection of multistory buildings. Foundation of piles and slabs includes piles and foundation frames of reinforced concrete. Foundation of piles and slabs includes reinforced concrete slab, protruding bars of which are rigidly fixed with protruding bars of foundation frames top parts. The slab is placed on prepared base, separated from foundation frames by seams filled with leakproof material and has minimum thickness providing acceptance of seismic loads.

EFFECT: necessary rigidity of pile foundations, compatibility of foundation elements deformations at forward and twisting forms of seismic loads.

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Description

The invention relates to the construction and can be used in the construction of multi-storey buildings.

Piled foundations are known in which piles bear the main load, and grillages are not taken into account in bearing capacity calculations (Ukhov SB et al. Soil mechanics, foundations and foundations. Ed. ABC, M., 1994, p. 308. Calculation and foundation design).

The disadvantage of such foundations is that despite the developed area of the sole of the grilles, the calculation methods do not take into account the perception of loads from buildings by grilles.

Known pile-slab foundations in which the heads of piles are combined with a slab-grillage. In such foundations (SP 50-102-2003 Design and construction of pile foundations, p.31, clause 7.4.10), it is recommended that 85% of the load is perceived by piles, and 15% by the slab. To ensure the rigidity of the plate, its dimensions, and most importantly the thickness, are supposed to be made large. The load distribution between the slab and the piles is not always possible to calculate correctly.

When designing in seismic areas, a technical solution is also known, including reinforced concrete piles and grillages connected by individual random beams (Ukhov SB and other Soil Mechanics, foundations and foundations. M., Higher School, 2002, p. 521, Fig. 17 ) However, this does not ensure the interaction of randbalks and grillages, especially during torsional vibrations, therefore it is much more efficient to combine grillages with a plate, ensuring independence of precipitation of individual grillages under static load.

The technical solution to the problem is to achieve the necessary rigidity of the pile foundations, ensuring compatibility of deformations of the foundation elements during translational and torsional forms of seismic loads.

The task is achieved by the fact that the pile-slab foundation, including reinforced concrete piles and grillages, according to the invention has a reinforced concrete slab, the reinforcement outlets of which are rigidly joined with the outlets of the upper part of the grillages, while the plate is located on the prepared base, separated from the grillages with seams filled with sealed material and has a minimum thickness, providing the perception of seismic loads.

The novelty of the proposed proposal is due to the fact that the piles in the bush, which absorb the loads from the columns of the frame building, are joined by rigid grillages separated by seams from the foundation foundation slabs, which allows the slabs to which the loads are transferred from the wall filling and the floor of the floor located above them to be made thin. Unlike ties in the form of random beams between grillages, the slab ensures the compatibility of grillages operation during torsional and translational vibrations.

Figure 1 shows a top view of a pile-slab foundation.

Figure 2 shows a section on which it is seen how to connect the reinforcing outlets of the plate with the reinforcing outlets of the upper parts of grillages.

The pile-slab foundation includes reinforced concrete piles 1, which can be either driven or drilled. After completing the soil in the soil, the piles in the bushes are joined by rigid reinforced concrete grillages 2, which are joined with the elements of the above-ground structures 3 (columns, load-bearing walls, etc.). In the intervals between grillages, a prepared base 5 is made on which a rigid reinforced concrete slab 6 is installed, having reinforcing outlets 7. Reinforced concrete grouts 2 also have reinforcing outlets 4. Reinforced concrete slabs 6 and grillages 2 are located so that between them remains a seam 8, necessary for rigid joining reinforcing releases 4 and 7, followed by sealing the seam with a sealed material.

The pile-slab foundation is erected as follows. First, piles 1 are immersed, combining them into bushes with grillages 2, which take up loads from the columns of the frame 3, providing for the release of reinforcement 4 from the upper part of the grillages 2, prepare the base 5 for the device of a thin plate 6, the releases of the reinforcement of which 7 are connected to the releases of the reinforcement 4 of the upper grillages 2. The concrete of grillages 2 is separated from the concrete of the slab 6 by seams 8, the width of which is assumed to be less than the calculated horizontal displacement of elements of grillages and slabs under seismic effects. The seams are filled with airtight material, which ensures the independence of sediments, but at the same time it solves the issue of waterproofing and the joint reaction of grillages to seismic events.

The dimensions of the slab to be arranged depend on the design features of the building being designed (column pitch, payload, etc.), as well as on the seismic characteristics of the construction site (site scoring), while the thickness of the structure is minimal - from 120 mm to 300 mm, t. to. horizontal stiffness required for the perception of shear and torsional forces, even for a relatively thin plate on an elastic base is very high.

Claims (1)

A pile-slab foundation, including reinforced concrete piles and grillages, characterized in that it has a reinforced concrete slab, the reinforcement releases of which are rigidly joined to the reinforcement releases of the upper part of the grillages, while the plate is located on the prepared base, is separated from the grillages with seams filled with sealed material, and has a minimum thickness providing perception of seismic loads.

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