UA34885A - Basement of building or structure - Google Patents

Abstract

The invention relates to the branch of building and is intended for use in basement building in usual conditions and at non-uniform deformations of bases. The basement of building or structure has support elements deepened to soil, cavities opened at outer surfaces of the basement, and joints.

Description

The invention relates to the field of construction and is intended for use in foundation construction under normal conditions and with uneven deformations of foundations.

An analogue of the invention in its essence is lattice foundations, which have cavities on the lateral surfaces of the foundation (see the book by M.I. Fidarov "Design and construction of intermittent foundations" - M. Building Publishing House, 1986 - page 29)

Spatial work is effectively used in these foundations due to the "arch" effect on the structure of the foundation. The design of lattice foundations with increased base load is characterized by reduced reliability. especially in conditions of detection of uneven deformations of the base itself, when there is a redistribution of the resistance pattern with the formation of additionally stressed zones. After the formation of increased resistance in the support elements, the spontaneous stabilization of the entire contact layer due to the existing cavities and the movement of the soil into these cavities occurs only after the complete formation of the marginal stiffness cores.

Lattice foundations are also not adapted to reduce loads from the contacting soil in conditions of development of forced horizontal movements of the soil massif.

Of the known technical solutions, block foundations are the closest to the proposed invention. equipped with cutouts on the support consoles, for example, curvilinear ones (see author's certificate Mo 1036845 under M class E02027/01).

In the conditions of detection of forced uneven vertical deformations of the foundations themselves, the rigidity of the support consoles along the length of the block is used ineffectively, which causes overstressing of individual protruding areas in the case of a parabolic shape of the support. The maximum stress of the ice on the sole of the block foundations due to the possible development in the conditions of overloads of excessive subsidence should be limited, which reduces the full use of the load-bearing capacity of the foundation soils. With forced horizontal deformations of the foundations, which always accompany vertical deformations, the load from the soil, which moves along the tangential and frontal side surfaces, cannot be reduced.

The task of the invention is to improve the foundation of the building, the structure due to the connection of struts at the level of the foundation, which fix the position of the foundation under shear loads of the soil and contact surfaces with cavities on the lateral level, which allows to reduce frictional forces and contact stresses.

Unlike the prototype, in which the cavities are located in a horizontal plane, the proposed foundation of the building has connections and cavities on the side surfaces, the side faces of which are curved, covered with an anti-friction layer and partially filled with soil.

The task is solved due to the fact that the foundation of the building contains support elements embedded in the ground, cavities that are open on the outer surfaces of the foundation, and connections.

According to the invention, the cavity is placed on the vertical outer surfaces of the support elements.

Thanks to the placement of cavities on the vertical outer surfaces of the supporting elements, a reduction in contact stresses on the lateral surfaces of the foundation is achieved due to the full use of frictional forces developed on them and the formation of uniform soil compaction with a high level of pressure of all prismatic sections of the foundation in contact with the soil.

In order to smoothly perceive deformation actions from the base, the side faces of the cavities are made curvilinear.

In order to reduce the frictional forces, the side faces of the cavities are covered with an anti-friction layer.

A flexible distribution layer of limited strength is placed between the cavities and the soil on the peripheral surfaces of the support elements in order to compact the base soil in the supporting and supporting areas.

The claimed invention is illustrated by drawings, where fig. 1 shows the foundation of a frame building, a building without a basement, a section (fragment); in fig. 2 - fragment from fig. 1; in fig. C - section B-B C fig. 2.

The proposed foundation of the building, the structure includes support elements 1, placed in the ground 2, which have a connection with Z and are equipped with cavities 4, made curvilinear with bases 5 and side faces 6. Side faces 6 of cavities 4 make up the actual side surfaces of support elements 1 Faces 6 form ribs 7 in the plane of the bases 5, which constitute the enveloping surface of the supporting elements 1. On the enveloping vertical surfaces of the supporting elements 1, between the soil 2 and the pyramidal cavities 4, a flexible layer 8 is placed. sections 9 of the side faces of 6 cavities 4. On the surface of the supporting elements 1, an anti-friction layer 10 is made, which is placed on the side surface of the foundation 11.

The claimed invention implements itself in this way. Relative to the vertically constructed enveloping planes of the support elements 1 of the foundation 11 of the building, the structure, the operating loads under normal engineering and geological construction conditions represent the active lateral pressure of a pound of backfill acting simultaneously from all sides.

At the same time, the foundation 11 is in a stable equilibrium state, and the areas of the support prismatic sections 9 are proportional in depth to the values of the lateral pressure ordinates, based on the calculation of reaching such limit resistances of the pound 2 at the contact, at which its static equilibrium state is maintained. Under the conditions of detection of the actions of forced horizontal displacements of the base, the normal loads along the frontal movements of the soil 2 are transformed into frontal passive pressure, and in the direction of movements of the Pound, lateral friction is caused, and in all cases, they are applied to individual supporting elements 1 skew-symmetrically and in magnitude much more than the usual active soil pressure 2. At the same time, an increase in the contact pressure on the support prismatic sections 9 above the limit values in statics is impossible and also leads to the fact that the soil 2, which approaches the contact, is plastically destroyed and moves freely into the cavities 4, as long as deformation actions are detected .

After that, the contact pressure decreases to the initial level, that is, the actual external surfaces of the foundation of the building, the building, cause the operation of the structure with constant resistance.

From the analysis of the given formulas, it follows that in addition to the loading force and deformation factors (М, б), some initial data with relatively independent freedom of choice (Н, Я) and the system of determining geometric coefficients (К, И, н, т), the main parameters ( n, 5, 2, M, B), which determine the dimensions, shape, strength of the material and reinforcement of the foundation 11 of the building, structure, are variable, mutually dependent and connected values, which fundamentally distinguishes the proposed foundation 11 from the prototype. So, to find the volume of cavities, use the following formula:

in 2 M NK. (6--H)- B) n B-(H-5-)- M n(sovo e. vipo))

G-U 2.M item 5. M (owl i E. vipo)) where M is the volume of cavities;

M - external normal load relative to the surrounding surfaces of the supporting elements, which acts either vertically or horizontally;

A - the ultimate bearing capacity of the foundation, at which the static equilibrium of the foundation is established and maintained;

H - full depth of cavities;

H - depth of introduction of soil into cavities; b. the absolute value of the forced displacement of the base soil at the considered point;

C - the actual contact area of the supporting prismatic areas;

K is the margin factor for the contact area, which takes into account possible changes in the estimated force loads;

I - coefficient of friction between the soil and the supporting prismatic sections; 1 - the generalized factor accounting for the shape of the volume of prismatic sections and their area of projection on the enveloping surfaces of the supporting elements; n - coefficient of transfer of contact pressures into their projection on the normal axis to the enveloping surface of the supporting elements; o - the angle formed by the enveloping plane of the supporting elements and the tangent plane drawn to the surface of the prismatic sections at the height of p.

So, if in the prototype the area 5 is set as the initial information, and the EC calculation is an independent independent operation, then in this case the final result is a joint solution of the combined formulas. If in the prototype, accounting for parameter и turns out to be an optional solution, then in this case, the construction of the foundation 11 without accounting for this factor is impossible, that is, during the operation of foundation 11, parameter и arises automatically according to the nature of the interacting materials. The depth of introduction of the soil 2 into the cavity 4 corresponds to the defined contact area of the support prismatic areas 9 5 and the constant limit resistance of the soil 2 of the base P, at which a steady state of static equilibrium is observed.

It should be noted that for the lateral planes of the supporting elements 1 of the foundation 11 of the building, structure, load fluctuations are not so significant for deformations of the entire skeleton and are more reflected in changes in internal forces that prevent possible deformations in the direction. The necessary strengthening of the structures according to the T parameter depends on the accepted stock factor K and is found using the formula: 1nn| owl ---

With and

TtT5--- - - with | 1 t , 2 4 where T is the total horizontal load that occurs on the sole of the foundation from the displacement of the soil;

A - the ultimate bearing capacity of the foundation, at which the static equilibrium of the foundation is established and maintained;

C - the actual contact area of the supporting prismatic sections;

Y - coefficient of friction between the soil and supporting prismatic sections; o - the angle formed by the enveloping plane of the support elements and the tangent plane drawn to the surface of the prismatic sections at the height y: t - the coefficient of transfer of contact pressures in its projection on the axis, which is parallel to the enveloping surface of the support elements.

For the side planes of support elements 1, the stock factor K is taken to be close to unity. and for the lower planes of supporting elements 1, this coefficient is much higher, which ensures high reliability of the operation of the building, structure.

The curvilinearity of the side faces b of the pyramidal cavities 4 is necessary to expand the possibilities of adjusting the planes of the supporting prismatic sections 9 of the outer planes of the supporting elements 71 in different ratios depending on the specific physical and mechanical properties of the base soils. That is, the change in the planes of the supporting prismatic sections 9 can follow both a linear and any non-linear law that increases or decreases.

The anti-friction layer 10 on the side faces 6 of the pyramidal cavities 4 is intended, on the one hand, to reduce the frontal resistance forces, which is especially necessary to protect the foundations 11, standing separately, or foundation walls from forced horizontal movements of the soil 2 of the base. It should be noted that in analogues, the introduction of an anti-friction layer 10 on the frontal surfaces of the support elements 1 relative to the direction of horizontal movement of the soil 2 does not in any way reduce the frontal loads that occur at that time. as in the proposed solution, the frontal loads are reduced to a known low limit due to the rational distribution of the forces of the side faces 6 of the cavities 4, due to their pyramidal (pyramidal-cylindrical) shape in accordance with the friction coefficient of the anti-friction layer 10, which ensures the free movement of the soil 2 into the depth of the cavities 4 and moving it away from the stressed supporting prismatic areas 9.

Separate flexible layer 8 of limited strength, designed to provide preliminary compression of the loose upper layer of the soil 2 of the base in the initial stages of loading, to ensure the storage of cavities 4 on the lateral outer surfaces of the supporting elements 1 during the backfilling of the soil 2, as well as in a number of cases for constructive organization of the anti-friction layer 10.

Depending on the type of foundation 11 buildings. structures, operating loads and forced values of uneven soil deformations 2, pyramidal cavities 4 are arranged on the outer vertical surfaces of support elements 1. On vertical surfaces, pyramidal cavities 4 can be arranged from four, two, or one side. In addition. pyramidal cavities 4 can be of different depths, closed or open, open. The side faces b of the pyramidal cavities 4 can have curvature, which is described according to any law. can have cylindrical sections along the depth of the cavities, and the surfaces of the side faces can be rough, with any given structure of micro-irregularities or smooth. The ribs 7 of the side faces 6 can be degenerate in the case of their colocylindrical curvature. The bases 5 of the pyramidal cavities 4 can have shapes with a different number of sides that touch each other. The anti-friction layer 10 can be made in the form of lubricants, soluble mixtures or complex compositions, for example, bituminized enamels, as well as in the form of sheet or film materials. The anti-friction layer 10 can be made on the side faces of the whole surface or partially. The dividing flexible layer 8 can be made in the form of a material that self-destructs in time, for example, non-rot-resistant construction cardboard, or in the form of a film-like flexible material of low strength that stretches under the influence of the mass of soil that is moved. The dividing flexible layer 8 can perform the function of an anti-friction layer 10. In addition, the anti-friction layer 10 can perform the function of a constructive formwork in the manufacture of supporting elements y7.

In the initial period of the construction of the building, structure, that is, when the external normal load has a minimum or "zero" value, the actual contact area 5 of the supporting prismatic sections 9 and the depth Pp of the introduction of soil 2 in the cavity 4 are also minimal, and the actual contact pressure is close to bearing properties of the base at a given degree of soil compaction. In the process of erecting a building, the load M increases proportionally, and together with this, the depth of introduction Pp and the actual contact area 5 of the support elements 1 increase. Moreover, the actual pressure on the contact is, at a given degree of compaction of the pound 2 under the support prismatic sections 9, a parameter close to in size to the ultimate bearing capacity of the base. For the calculated full load M according to the above-mentioned formulas, the geometric parameters of the supporting elements 1 of the foundation 11 of the building, structures are selected in such a way that the accepted coefficient of reserve K, given by the parameter Пп and 5, corresponded to the ultimate load-bearing property of the base B. In this position, all the supporting elements 1 of the foundation 11 buildings, structures occupy a stable state of static equilibrium. That is, the possible increase in additional subsidence (increase in the depth of introduction of Pp), associated with possible fluctuations of the calculated normal loads M, is very insignificant and according to the deformation criteria of movement irregularities is within the limits of the values allowed by technical and sanitary standards.

The described condition is also typical for the side surfaces of the supporting elements 1 of the foundation 11 of the building. Here, instead of the external normal load, there is a lateral pressure of the soil 2 of the return note, the fluctuation of which in magnitude in specific zones is completely insignificant. Thus, in this case, in proportion to the ordinates of the lateral pressure, the contact areas of the supporting prismatic areas 9 are formed, on which contact pressures appear that approach the load-bearing properties of the base at a given degree of soil compaction 2.

In comparison with the prototype, the declared foundation 11 of the building, the structure provides a reduction in its material intensity and the load from the contacting soil 2 on its surface. Moreover, the reduction of concrete costs of supporting elements 1 is not only due to the formation of cavities 4, but also due to the reduction of internal forces in the structure and the reduction of the dimensions of the elements themselves according to analogues, that is, within the limits of the given foundation 11, not only concrete is saved, but also reinforcing steel.

The proposed foundation 11 is distinguished by the high reliability of the operation of the entire building, the structure in the critical situation of an unforeseen emergency increase in force load is explained by the very work of the structures, that is, with increasing load, the support areas of the prismatic sections 9 are constantly increasing, and since at the same time the volume of the cavities 4 is early or later will be completely filled with soil 2, it is certain that the supporting area of the foundation 11 will increase significantly, and the average pressure will decrease with the achieved degree of compaction. However, after that, the foundation 11 will not be able to work in the system of self-adjustment of contact pressures. in -8 7. she s her Shky o same UVU UT UVIKUUYUVYTINU . but at 7:00 p.m.; / y y c. " ' u sa I ShK ay 7 y din du ZHI noi ---- s "sD/. things Rv st I her tuz ' sugi | in Y SN,

I, I you Y ru gy t py rya J. in 1 .

Fig. 1

What year

MILY, b sho Ж s, GU ; ODB. . t ut st. 4 Uh Y us.

KUA LAMA

SVY V y ra z 4 4 m Zhe uk i U UI u o DAK - ID, "U U zhu 75 era OKO i gr, o

SA Fo. ay b shi she Fig2 ' 5: b Y 7 id t y (U y . My ; ; I Y, con UA s-g KI sitzhu'lu 7 su pr. Ru. - U 5 in KK

I'm crooked

SUK KU Shchy, 44

KK, nn A,

He is still 5; whether the US kash 2 ku Code 5 Zh u i g a BD y

DE t» A AV

Ua UVK VV o U DYA VU and o Fig. 3.

Claims (4)

1. The foundation of the building, the structure contains support elements, cavities buried in the ground, which are open on the outer surfaces of the foundation and a connection, which is distinguished by the fact that the cavities are placed on the vertical outer surfaces of the support elements. 2. The foundation of the building, the structure according to claim 1, which differs in that the side faces of the cavities are curved. 3. The foundation of the building, the structure according to claim 1, which differs in that the side faces of the cavities are covered with an anti-friction layer. 4. The foundation of the building, structure according to claim 1, which is characterized by the fact that a flexible separating layer of limited strength is placed on the circumferential surfaces of the supporting elements between the cavities and the soil.