SU1620544A1 - Method of erecting pile foundation with solid framing on heaving and swelling grounds - Google Patents

Abstract

The invention relates to the construction, and in particular to methods for erecting pile foundations of buildings and structures with monolithic grillages on heaving and swelling soils. The purpose of the invention is to increase the effectiveness of reducing the effects of normal swelling forces, stumps and increasing the durability of foundations. The method is carried out as follows. Piles are poured into the ground, a layer of porous thermal insulation material is applied to the surface of the soil in the interwave space, the material is jointly loosened with the soil to a height H determined by the formula given in the description until an average density p 0.6 1.1 g / cm3. Then, in the upper layer with a thickness of (0.2-0.1) H, the mixture is compacted until the density reaches 0.85 g / cm3 p sC 1.3 g / cm3 and the grillage is concreted. The quick-hardening building foam or antifoam-gas silicate is used as a heat-insulating material. After casting with a grillage of necessary strength, a mixture of soil and material is deposited, forming a gap. Under the influence of swelling forces, the stump of the gap decreases in volume and thickness. As a result of compaction of the loosened mixture, sediment occurs to a certain limit, at which the swelling forces do not exceed the balancing force of their own weight of the foundation. 2 h. the item of f-ly, 4 ill. Ј (/

Description

The invention relates to the construction, and in particular to methods for erecting pile foundations of buildings and structures with monolithic grillages on heaving and swelling soils.

The purpose of the invention is to increase the effectiveness of reducing the effects of normal swelling, stomping and increasing the durability of foundations.

FIG. 1 shows a pile foundation, a general view; in fig. 2 - pile foundation during concreting of the grillage; in fig. 3 — fragment of the foundation after concreting; in fig. 4 - the same, when swelling the soil.

The method is carried out as follows.

Piles 2 are immersed in soil 1, a layer of porous thermal insulation material 3 is applied to the surface of the soil in the interwave space, the material 3 is jointly loosened with soil at a height of H, determined by

0

go

about ate

-U

- ICE

H -; - j-Pcha

Ј0.um.

+ (0,2--0,1) Н,

where Ah - the required amount of sediment;

pdpasp is the density of dry, loose soil particles before compaction;

pdyn.i is the density of particles of dry loosened soil after compaction during swelling, heaving,

 Dmat - sediment of particles of material, defined by the ratio

DNmat Pma- (hKpc),

where Lmat is the thickness of the material

Kos - coefficient of precipitation, equal to the ratio of the final volume of this material to the original volume.

to achieve an average density of p-0.6-1.1 g / cm3. Then, in the upper layer, with a thickness of (0.2-0.1) N, mixture 4 is compacted until an average density of 0.85 g / cm 3 p 1.3 g / cm 3 is reached.

As a heat insulating material, quick-hardening construction foam or foam-gas silicate can be used. After the upper layer 5 is compacted, the grillage 6 is concreted. After the concrete grinder 6 has a set of necessary strength, the preparation from the mixture of loosened soil settles, forming a gap 7, and when subjected to swelling forces, the heel compresses by 8, decreasing in volume and thickness. At the same time, as a result of compaction of the loosened mixture, a sediment occurs to a certain limit, at which the swelling forces do not exceed the balancing force of their own weight of the foundation.

Claims (3)

1. A method of erecting a pile foundation with a monolithic grillage on heaving and swelling soils, including sinking piles, forming, on the basis of preparation, a monolithic grillage from local soil by loosening it and then compacting it, erecting a grillage, characterized in that, in order to increase the effectiveness of reducing the normal forces of swelling, stomping and increasing the durability of the foundation, before loosening the local soil, a layer of porous thermal insulation is applied to its surface the first material and performing a loosening of the joint until reaching medium density, 6-1,1 g / cm3 at a height H emomu determined by the formula: AI-DNmat. j n -j - + b | at + (y-) n0 five Jb ull where Ah is the required amount of precipitation (clearance); Dmat - sediment of particles of material, defined by the ratio Dmat Lmat (1K ° s), where Lmat is the material thickness; Kos is the precipitation coefficient equal to the ratio of the final volume of this material to the initial volume; Ryo is the density of particles of dry loosened soil before compaction; - density of particles of dry loosened soil after compaction during swelling, heaving, and the mixture is compacted in the upper layer with a thickness of (1/5 ... 1/10) H until the average density of the mixture is reached, determined from the condition of 0.85 g / cm3, 3 g / cm3. 2. A method according to claim 1, characterized in that a layer of fast-hardening construction foam is applied to the surface of the local soil. 3. The method according to claim 1, characterized in that a layer is applied to the surface of the local soil 5 penogazosilicata. pdyn 1 V ir-y .. ii, /// /// rr /// b44 r FIG. 2 R L T L I f  g:: 1 / x | /// U // four 8- ± (Precipitation) t one Fig.Z ghhuhagl. one . : V: j -: .. V, .Y / Z. FIG. four