RU121274U1 - ARTIFICIAL REINFORCED BASIS FOR ESTABLISHED OR RECONSTRUCTED BUILDING - Google Patents

Abstract

1. An artificial reinforced base for an erected or reconstructed building, which is a soil-cement reinforced massif, including metal non-retrievable injectors with a blind, perforated part and a tip, made of pipes with a diameter of 32-76 mm, driven into wells pre-drilled through the foundation of a building being erected or reconstructed and located in a checkerboard pattern in several rows, including a barrier row made around the perimeter of the artificial foundation outside the foundation of the building, and the injectors are monolithic with a blind part into the body of the foundation, and through them an injection cement mortar is introduced into the ground under surcharge. ! 2. An artificial foundation according to claim 1, characterized in that in one well there are several injectors of different heights, intended for alternately cementation of several zones of the soil to be strengthened, and the perforated part of each subsequent injector is located below the perforated part of the previous one, without overlapping it. ! 3. An artificial foundation according to claim 1, characterized in that the surcharge is first provided by concrete preparation, and then by the body of the structure or by the foundation slab. ! 4. An artificial base according to claim 1, characterized in that the injection solution, in addition to cement and water, contains cement dust and water glass, or cement dust, bentonite clay and water glass, or cement dust, fine sand and water glass, or liquid glass. ! 5. Artificial foundation according to claim 1, characterized in that the wells are located vertically and / or obliquely. ! 6. An artificial base according to claim 1, characterized in that each injector is

Description

The utility model relates to the field of construction and can be used in the engineering preparation of construction sites for new construction, as well as for strengthening the foundations of existing buildings in solving the problems of losing their load-bearing capacity, in building superstructures, when there is a need to expand the foundation, or when reconstructing buildings.

Known methods for the preparation of artificial bases:

- by compaction of soils (by ramming with heavy rammers, arranging soil piles, ramming foundation pits, pre-soaking soils, using blast energy, deep hydraulic vibratory compaction, vibrating machines, rollers, etc.);

- full or partial replacement at the base of soils with unsatisfactory properties with sand, gravel, crushed stone, etc. pillows;

- the device of embankments (dumping or hydraulic washing);

- soil fixation (chemical, electrochemical, mixing, thermal and other methods);

- the introduction of special additives into the soil (for example, salinization of the soil or its impregnation with oil products to eliminate heaving properties);

- soil reinforcement (the introduction of special films, nets, etc.);

- by driving piles.

It is known, for example, artificial reinforced base (RU 2380482, IPC E02D 3/12, publ. 01.27.2010). which is a reinforced soil mass, which is obtained by injecting a compacting solution through injectors. Reinforcement is provided by a system of vertical volumetric elements of increased density, which are formed in the soil after its soaking and compaction as a result of injection of a suspension of carbonate sludge into the formed cavities under a pressure of 3.5-4.0 MPa. Injectors are removed from the soil after injection of the injection solution.

The disadvantages of the known methods are: insufficient bearing capacity of the obtained soil, the impossibility of driving or crushing piles due to the presence of reinforced concrete and metal buried objects in bulk soils. In addition, there are dynamic effects when driving piles on nearby existing buildings and structures, and the high cost of work.

The objective of the utility model is to increase the bearing capacity of soils during the engineering preparation of construction sites for new construction or to strengthen the soil foundations of existing buildings, reduce the cost of work, reduce the construction time of buildings and structures.

The problem is solved by an artificial reinforced base for a building being constructed or being reconstructed, which is a soil-cement reinforced array, including non-removable metal injectors with a deaf, perforated part and a tip made of pipes with a diameter of 32-76 mm, driven into pre-drilled wells through the foundation of a building being constructed or being reconstructed, and staggered in several rows, including a barrier row made along the perimeter of the artificial base outside undamenta building, the injectors are hardwired into the body hollow part of the foundation, and through them into the ground introduced under prigruzami injectable grout.

According to the utility model:

- in one well there are several injectors of various heights, designed for alternately cementing several zones of soil to be strengthened, the perforated part of each subsequent injector being located below the perforated part of the previous one without blocking it;

- the load is first provided with concrete preparation, and then with the body of the structure or foundation slab;

- the injection solution, in addition to cement and water, contains cement dust and water glass or cement dust, bentonite clay and water glass, or cement dust, fine sand and water glass, or water glass;

- wells are located vertically and / or inclined;

- each injector is fixed in the well by a packer, which can be both superficial and deep;

- when the diameter of the drilled well exceeds the diameter of the injector by more than 30 mm, the annular space of the blind part of the injector is cemented.

The specified technical result is achieved due to the following. Cement solution is injected into the soil through injectors under high pressure (5-20 atm). The solution penetrates through the hydraulic fractures caused by pressure into the caverns and cracks located between the rows of injectors, filling them, which allows to strengthen the weakest zones of the soil mass to the maximum extent. Areas into which the injection solution did not penetrate are also amplified, as they change their physical and mechanical properties: as a result of hydraulic fracturing caused by the high working pressure of the injected solution, they are compressed and compacted. Non-recoverable injectors serve as elements of vertical soil reinforcement. Monolithic with their deaf part to the foundation and entering the ground with a pointed edge, they perform the function of micro piles.

The installation of several injectors in one well makes it possible to strengthen the soil layers of various depths, which have their own characteristics and require solutions of different compositions, and can solve several problems simultaneously: for example, strengthening the foundation, anti-karst measures at depth, and reducing filtration. The monolithic injectors in the foundation prevents their discharge and contributes to a more rigid fit, prevents shifts when the solution is injected into them under high pressure. Since the injectors are made of a metal pipe, their deaf part monolithic in the foundation serves as an additional reinforcement of the foundation.

The addition of cementitious binders such as cement dust, sand, bentonite clay to the cement mortar reduces the cost of strengthening the soil and improves its physical and mechanical properties. In this case, cement is included in the solution only in a small amount (20-50% of the total number of dry mixes).

The barrier row of injectors serves as a curtain to prevent the injection of solution beyond the boundaries of the artificial base area.

The utility model is illustrated by drawings, where

figure 1 shows a diagram of the inventive artificial reinforced base, top view;

figure 2 - arrangement of injectors in the ground.

The artificial reinforced base contains non-recoverable metallic injectors 1. Position 2 denotes the foundation, and the technogenic mass formed from reinforced soils located under the base of the foundation, position 3.

An artificial reinforced base is constructed as follows.

Wells are drilled for concrete preparation, injectors 1 are installed in them, having a blind, perforated part and a tip of 50-100 cm. A barrier row of injectors 1 is created along the perimeter of the artificial base. Inside the barrier row, the injectors are driven into pre-drilled wells. The size of the mesh depends on the composition and properties of soils and can range from 1.5 × 1.5 m to 5 × 5 m. All injectors with a tip enter the soil to be strengthened. The deaf part of the injector 1 is monolithic in the foundation 2. In one well, several different heights of injectors can be installed, designed for successively cementing several zones of soil to be strengthened at different depths, and when installing more than one injector in the well, it is carried out so that the perforated part of each the subsequent injector was located below the perforated part of the previous one, without blocking it. In this case, when installing several injectors, the second injector will have a blind part equal to the perforated part of the first injector, and when installing the third injector, the height of its blind part will be the sum of the heights of the perforated parts of the first and second injector for the exact spreading of the injection cement mortar over each of the reinforcement zones (cementation) in depth.

Next, work is carried out on injection through the injectors 1 under the load created by the building, the injection of cement into the soil with ensuring its hydraulic fracturing at a pressure of 5-20 bar. Injection solution is injected into the injectors of the barrier row first, two to every third, passing a circle three times along the barrier row, and the solution injected into them has a more viscous consistency than the solution injected into the injectors inside the barrier row and contains quick-hardening additives. If there are two or three injectors at one injection point, cementation of the soil zones in depth is carried out in stages

- in a descending or ascending way (from a shorter injector to a longer one or vice versa).

Cement dust and water glass, or cement dust, bentonite clay and water glass, or cement dust, fine sand and water glass, or water glass are added to a cement mortar consisting of cement and water. The injection solution is fed into the soil to be strengthened through each injector in stages, creating a layered soil-cement compound in it, and after introducing 1/3 of the design amount of the solution, the injector is washed and filled with clay-bentonite solution, shut off with a ball valve installed on each injector, and settled in in this position for a day, after which further injection of the solution is carried out. When several injectors are installed in the well, injection of the injection solution through them is carried out in stages, starting from a lower injector to a larger one or vice versa. The injection of the injection solution over the area is carried out in stages by a gradual approximation, starting with the most distant injectors.

The order and conditions of the work is different depending on the properties of the soils, the tasks set (antifiltration works, geotechnical anti-karst works, strengthening bulk or suffusion soils in order to improve their physical and mechanical properties). For example, the injection of solutions in fractured rocky and karst soils is carried out in one zone, immediately to the entire depth of cementation. The size of the zone is set by the project. As a result of the introduction of the injection solution into the soil, a new technogenic array 3 is created having improved physical and mechanical properties.

At the end of cementation, the aerial part of the injector is cut off and filled with a cement plug. Thus, injectors are non-recoverable and serve as elements of vertical reinforcement.

Examples of specific performance of the utility model at various objects (5 objects) are shown in tables 1-3.

Table 1. Object number Type of soil, features The purpose of soil strengthening The number of solutions used additives one Soils are highly permeable, open karst cavities, marl, mudstone, sandstone, karst-suffusion process Strengthening the soil at the base of piles, lowering the filtration. Two solutions injected into two injectors: liquid sodium glass was added to one, bentonite clay and liquid potassium glass to the other. 2 Landslide, subsidence soils and sulphate-carbonate karst (loam) Foundation soil reinforcement 1 solution containing liquid sodium glass as an additive. 3 Sulphate-carbonate karst, landslide processes, heaving of soils, 2-category of soils. strengthening soil base, lower filtration. Bentonite clay (1 solution) was added to the cement mortar. four landslide, subsidence soils and sulfate-carbonate karst (bulk soils). elimination of a landslide hazard situation. Liquid potassium glass (1 solution) was added to the cement mortar. 5 bulk non-caking soil, sand, gravel, stone fragments, clay and sandstone soil layers. an increase in the bearing capacity of piles not driven according to the design, shortened and in smaller quantities. Cement dust, liquid sodium glass (1 solution) were added to the cement mortar.

Table 2.

Property Number Deformation modulus, MPa specific adhesion, MPa filtration coefficient, ms porosity coefficient angle of internal
friction, hail. density s / cm3

one 9-27 0.018-0.057 25.16 25 to 40% more 10 sh / m 16-24 1.84-2.04 2 7-16 0.007-0.024 0.708-0.786 15-23 1.8-1.96 3 7-18 0.012-0.035 10-20 1.80-2.0 four 7-16 0.007-0.024 0.708-0.786 15-23 1.8-1.96 5 18 t / s

Table 3.

Property Number Physico-mechanical properties of the resulting reinforced base deformation modulus, MPa specific
grip, MPa filtration coefficient, ms porosity coefficient angle of internal friction, degrees density, g / cm3 one 32-40 0.042-0.081 0.011-0.034 28-36 2.35-2.45 2 28-30 0.2-0.3 0.27-0.44 0.63 21-24 1.96-2.2 3 40 2.3-2.55 four twenty 0.1-0.25 21-24 5 37 t / s

As can be seen from the tables, as a result of the construction of the artificial foundation, a significant improvement in the physicomechanical properties of soils is achieved, which become suitable for accepting design loads. A single reinforced massif is created with the same soil density over the entire area of the base, which prevents uneven settlement of the building.

When installing an artificial base, small-sized equipment that does not carry out harmful emissions into the atmosphere is used. Production is almost waste-free. Materials are used only of organic origin. The erection of an artificial base is possible on almost all types of soils: rocky and semi-rocky, karst, incoherent (sand, gravel, pebble), bulk and subsidence. Artificial base can be used for any type of foundation: slab, strip, columnar. Work can be carried out in parallel with the construction of the building. The cost of work is lower than the cost of piling fields by 15-20%. In the process of constructing an artificial foundation, the filtration coefficient decreases by 2-3 orders of magnitude, which prevents the soaking of the base of the building erected on flooded soils throughout its entire life. At the same time, the device of reservoir drains is not required, which gives significant savings.

Thus, as a result of the application of the utility model, the bearing capacity of soils increases during the engineering preparation of construction sites for new construction or to strengthen the foundations of existing buildings, cheaper work is achieved, and the construction time for buildings and structures is reduced.

Claims (7)

1. An artificial reinforced base for a building being constructed or being reconstructed, which is a soil-cement reinforced massif, including non-removable metal injectors with a deaf, perforated part and a tip made of pipes with a diameter of 32-76 mm, driven into pre-drilled wells through the foundation of a building being constructed or being reconstructed, and staggered in several rows, including a barrier row made along the perimeter of the artificial base outside the basement of the building I, and the injectors are monolithic with a deaf part into the foundation body, and through them injection cement mortar is introduced into the soil under load. 2. The artificial base according to claim 1, characterized in that in one well there are several injectors of various heights, designed for alternately cementing several zones of soil to be strengthened, the perforated part of each subsequent injector being located below the perforated part of the previous one without blocking it. 3. The artificial base according to claim 1, characterized in that the load is first provided with concrete preparation, and then with the body of the structure or foundation slab. 4. The artificial base according to claim 1, characterized in that the injection solution, in addition to cement and water, contains cement dust and water glass, or cement dust, bentonite clay and water glass, or cement dust, fine sand and water glass, or liquid glass. 5. The artificial base according to claim 1, characterized in that the wells are vertically and / or inclined. 6. The artificial base according to claim 1, characterized in that each injector is fixed in the well by a packer, which can be both superficial and deep. 7. The artificial base according to claim 1, characterized in that when the diameter of the drilled hole exceeds the diameter of the injector by more than 30 mm, the annular space of the blind part of the injector is cemented.