RU2652041C1 - Plate-frame foundation for a low-rise construction on soft grounds - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to construction of foundations of low-rise buildings on soft soils. Slab-frame foundation for low-rise construction on soft soils comprise a strip reinforced concrete foundation under all bearing walls of a factory-built slab building, connected to each other and united in a system of crossed strips laid on an aligned base on a waterproofing layer in the form of a film under the entire building. Each of the slabs of the strip reinforced concrete foundation is made in the form of a shell of rigid cross-section shape of a spatial and closed type with inside insulator of any type. Shell is formed by the upper and lower slabs of the spatial type, connected to each other, the lower slab is provided along the length of the sides, and the upper slab is made with ribs, grooves are made in the sides and in the lower part of the ribs, in the grooves the keys are embedded, by means of which the upper and lower slabs are interconnected. In the places of joints the slabs are provided with the outlets of the armature for docking with the armature of adjacent elements with knot embedment, and the space between the slabs of the frame is embedded with a soil mass and a layer of insulation on top, forming the bearing structure of the floor of the first floor. Upper slabs of the strip reinforced concrete foundation are made of a U-shaped cross-section with variable thickness of the ribs along the cross-sectional height, increasing towards the upper part of the section joining the ribs, inner surface of which is curvilinear and made to provide rational distribution of reinforced concrete along the section, according to the diagram of contact stresses.

EFFECT: technical result is increased rigidity and efficiency of the slab-frame foundation on soft soils, reduced material consumption of the slab-frame foundation for low-rise construction.

1 cl, 2 dwg

Description

The invention relates to the construction of foundations of low-rise buildings on soft soils.

There is a well-known foundation for low-rise construction on soft soils, including a tape reinforced concrete foundation under all the bearing walls of the building from interconnected cross tapes combined into a system, while the foundation is made in the form of a slab-frame foundation in a monolithic or precast-monolithic design, laid on a leveled the base on the waterproofing layer in the form of a film for the entire building, including the blind area, the cross-section of the elements of the slab-frame foundation has a closed box-like shape, consisting of a top of them and lower reinforced concrete slabs combined with extreme lateral and middle thickened ribs, between which a slab insulation is laid, the space between the frame elements is laid by the earthen mass and a layer of insulation on top, forming the supporting floor structure of the ground floor, and in the monolithic construction, the elements of the slab-frame the foundation is made in the factory version as prefabricated with the release of reinforcement for docking with the reinforcement of adjacent elements with monolithic site (RF Patent No. 1055637 U1, priority date 01/11/2011, date public tion 06/20/2011, authors Abovsky NP et al., RU).

The disadvantages of the analogue are: insufficient rigidity of the frame to ensure low sensitivity to uneven soil deformations; low heat-shielding properties due to the presence of a partition in the said section of the element, made in the form of a thickened rib; increased concrete consumption for the implementation of the element with a thickened middle rib with increasing height to ensure sufficient rigidity.

Known slab-frame foundation for low-rise construction on soft soils, adopted as a prototype, including tape reinforced concrete foundation under all the bearing walls of the building from factory-made plates, interconnected and combined into a system of cross tapes laid on a leveled base on a waterproofing layer in the form films for the entire building, each of the plates is made with a closed-shape cross-section with a heater located inside, and the space between the frame plates is laid by the ground mass and the layer insulation on top, forming the supporting structure of the floor of the first floor, while the slabs of the strip reinforced concrete foundation under all the bearing walls are made in the form of a trapezoidal rigid shell of a cross-section of a spatial and closed type, formed from the upper and lower plates of the spatial type, interconnected, while the lower plate made wider than the top and provided with sides along the length, and the top plate is made with inclined ribs, and grooves are made in the sides and at the bottom of the inclined ribs, in which the dowels are numbered, by means of which the upper and lower plates are interconnected, and at the joints of the plates they are equipped with releases of reinforcement for joining adjacent elements with reinforcement with the assembly of the assembly (RF Patent No. 2496943 C1, priority date May 14, 2012, publication date October 27, 2013, Authors Abovsky N.P. et al., RU, prototype).

The disadvantages of the prototype are: insufficient rigidity of the element of the slab-frame foundation due to the trapezoidal cross-sectional shape of the upper slab of the element, as well as the inefficient consumption of concrete on the widened lower slab.

The objective of the invention is to increase the efficiency of the slab-frame foundation for low-rise construction on soft soils by increasing stiffness, as well as reducing concrete consumption.

To solve this problem, a slab-frame foundation for low-rise construction on soft soils is proposed, including a reinforced concrete strip foundation under all the bearing walls of the building from factory-made plates connected together and combined into a system of cross tapes laid on a flat base on a waterproofing layer in the form of a film under the entire building, each of the slabs of the strip reinforced concrete foundation is made in the form of a rigid shell of a cross section of a spatial and closed type with with any type of insulation inside, the shell is formed of the upper and lower spatial type plates connected to each other, while the lower plate is provided with the sides along the length, and the upper plate is made with ribs, and grooves are made in the sides and in the lower part of the ribs dowels, by means of which the upper and lower plates are interconnected, in addition, at the joints of the plates are equipped with releases of reinforcement for joining adjacent elements with reinforcement with monolithic assembly, and the space between the plates of the frame is laid ground mass and a layer of insulation on top, forming the supporting structure of the floor of the first floor. According to the invention, the upper slabs of the strip reinforced concrete foundation are made in a U-shaped section with variable thickness of ribs along the section height increasing towards the upper part of the section uniting the ribs, the inner surface of which is made curved with the possibility of ensuring rational distribution of reinforced concrete over the section according to the contact stress diagram.

The U-shaped cross-sectional shape was not chosen by chance, because relying on the diagram of contact stresses at the base of the foundation, you can find the places of the greatest stress values on the foundation. Thus, it is possible to identify places where the maximum amount of reinforced concrete is needed, and where the minimum (Fig. 5.4, p. 120, "Soil mechanics. Foundations and foundations" - Ukhov SB, Semenov VV, Znamensky V.V. .).

The effectiveness of the inventive slab-frame foundation for low-rise construction on soft soils is based on all the advantages inherent in the prototype compared to well-known analogues, and the increase in its effectiveness is due to a change in the cross-sectional shape of the upper foundation plate in the form of a U-shaped shell with a variable thickness of ribs by section height. Due to the change in the cross-sectional shape of the upper plate, the issue of material consumption was resolved, since as a result of the removal of inefficient zones, the cross-sectional area, including the lower plate, and, therefore, the material consumption of the foundation elements, were reduced. However, the invention also solves the problem of insufficient rigidity, compared with the prototype, due to the rational distribution of reinforced concrete in the cross section of the slab.

At the same time, the design of the slab-frame foundation allows the use of slab insulation and other types of insulation, which lack strength properties.

Thus, the claimed design of the slab-frame foundation for low-rise construction on soft soils is most effective compared to the known analogues due to the reduction of labor costs in the construction of the foundation on soft and heaving soils, increasing rigidity, reliability of operation, improving heat-shielding properties and reducing concrete consumption and reinforced concrete.

The technical result achieved by the claimed design in comparison with the prototype is to increase the rigidity and reduce the material consumption of the slab-frame foundation for low-rise construction.

The invention is illustrated by drawings, where in FIG. 1 shows a fragment of a section of the foundation; in FIG. 2 - assembly of the foundation plate.

The slab-frame foundation for low-rise construction on soft soils is made under all the bearing walls of building 1 and consists of plates made in the form of a rigid shell of a cross-section of a spatial and closed type, formed from the top plate 2 and the bottom plate 3 of the spatial type, interconnected. The upper plate 2 is made of a U-shaped section with a variable thickness of the ribs 4 along the section height increasing towards the upper part of the section, combining the ribs 4, and the inner surface of the upper part is made curved to ensure rational distribution of reinforced concrete in the section of the plate. The lower plate 3 is provided with the lengths of the sides 5. In the sides 5 and in the lower part of the upper plate 2, grooves 6 are made in which the keys 7 are monochromatic, with which the upper 2 and lower 3 plates are interconnected. Moreover, the space between the upper 2 and lower 3 plates is filled with insulation 8 of any type. At the joints of the plates are equipped with releases of reinforcement 9 for docking with the reinforcement of adjacent elements with monolithic site.

A slab-frame foundation for low-rise construction on soft soils is laid on a leveled base 10 on a waterproofing layer 11 in the form of a film for the entire building. The space between the foundation slabs is laid with an earthen mass 12 and a layer of insulation 13 on top, forming the supporting structure of the floor 14 of the first floor. All elements of the tape reinforced concrete foundation are made in the factory version with the installation of mounting loops 15 in the bottom plate 3.

The construction of the slab-frame foundation for low-rise construction on soft soils is carried out as follows.

Several layers of waterproofing film 11 with a low coefficient of friction for the entire area of a low-rise building are laid on a leveled base 10. On the waterproofing film 11, under the load-bearing walls 1 of the low-rise building, the lower plates 3 are laid, for example, a plate insulation 8 is installed on them, then the upper plate 2 is laid on the lower plate 3 and they are joined by monoling the dowels 7 in the grooves 6. At the joints plates connect the releases of the reinforcement 9 of adjacent elements and perform monolithic nodes.

The space between the foundation elements on the inside is laid with an earthen mass 12 and a layer of insulation 13 on top, forming the supporting structure of the floor 14 of the first floor.

This design helps to reduce the cost of construction by reducing the volume of earthworks, which are minimized, since the device does not require an earth cushion and the use of specialized equipment.

Thus, having all the advantages of the prototype, the claimed design has significant advantages of a slab-frame foundation for low-rise construction on soft soils, and in connection with the improvement of the shape of the foundation elements and the implementation of the upper plate of a U-shaped section with a variable thickness of ribs along the section height, taking into account the rational distribution of reinforced concrete over the cross section in accordance with the contact stress diagram also acquires an additional effect, which consists in increasing the stiffness and reducing the material consumption of the foundation.

These advantages indicate that the claimed design is effective and has reliability, durability, efficiency.

Claims (1)

Slab-frame foundation for low-rise construction on soft soils, including a strip reinforced concrete foundation under all the bearing walls of the building from prefabricated slabs interconnected and combined into a system of cross tapes laid on a flat base on a waterproofing layer in the form of a film under the entire building, each made of slabs of tape reinforced concrete foundation made in the form of a rigid shell of a cross-section of a spatial and closed type with an insulation of any type located inside and it is formed from the upper and lower plates of a spatial type, interconnected, while the lower plate is provided along the lengths of the sides, and the upper plate is made with ribs, and in the sides and in the lower part of the ribs grooves are made in which the keys are monochromatic, with which the upper and the lower slabs are interconnected, in addition, at the joints of the slabs they are equipped with releases of reinforcement for joining adjacent elements with reinforcement with monolithic assembly, and the space between the plates of the frame is laid by the ground mass and a layer of insulation on top, bearing the supporting structure of the floor of the first floor, characterized in that the upper slabs of the strip reinforced concrete foundation are made of a U-shaped section with variable thickness of ribs along the height of the section, increasing towards the upper part of the section, combining the ribs, the inner surface of which is made curved with the possibility of rational distribution reinforced concrete cross-section, according to the diagram of contact stresses.

Images