RU121275U1 - REINFORCED GROUND-CEMENT WALL FOR PROTECTION OF BUILDINGS AND STRUCTURES FROM THE DIGGED NEAR THE CROWDED - Google Patents

Abstract

1. Reinforced soil-cement wall to protect buildings and structures from excavated near the pit, made in the form of a single soil-cement reinforced massif, including metal non-retrievable injectors in the form of pipes with a diameter of 32-76 mm, consisting of a blind, perforated part and points driven into pre-drilled along staggered wells with a part of the injectors inserted under the foundation of the building to be protected, and all injectors are tied by welding at ground level with a steel bar with a diameter of 10-20 mm, and through them injected cement mortar is introduced into the ground under load. ! 2. Reinforced soil-cement wall according to claim 1, characterized in that it occupies the area between the protected building and the side of the excavated pit, as well as part of the area under the base of the protected building, and the depth of the soil-cement wall is determined by the depth of entry into the ground of the tip of the injectors and exceeds the depth of the pit at least than 200 cm! 3. Reinforced soil-cement wall according to claim 1, characterized in that the surcharge is natural soils or a special slab. ! 4. Reinforced soil-cement wall according to claim 1, characterized in that the perforated part of the injector starts from the bottom of the foundation of the protected building, and the blind part is equal to the height of the foundation. ! 5. Reinforced soil-cement wall according to claim 1, characterized in that in one well there are several injectors of different heights, intended for cementation of layers of soil with different depths, and the perforated part of each subsequent injector is located below the perforated part of the previous�

Description

The utility model relates to the field of construction and can be used in the engineering preparation of construction sites for new construction in order to protect existing buildings from the effects of a deep excavation being excavated in the immediate vicinity for new construction, as well as to strengthen the sides of deep excavations.

To protect existing buildings and structures from the effects of being excavated near the foundation pit, mainly sheet pile fences made of bored piles, including those using large diameter metal pipes, are known today.

It is known, for example, the sheet piling according to the patent (RU 115372, IPC E02D 5/02, published April 27, 2012), which is a continuous wall of sheet piles made of a polymer material reinforced with fiberglass filler, interconnected by joining the profiled edge with a male shape and a profiled edge with a female shape and fastened by an external horizontal power belt.

Known construction for the localization and strengthening of soft soil (patent RU 89542, IPC E02D 17/18, publ. 10.12.2009), which contains a double sheet pile fence installed on the side of one of the side walls of the pit and filled inside to the level of the surface layer with a bulk layer, for example, from clay, drainage pipes located around the perimeter of the pit, and the surface layer covering the pit on top, with a geomembrane placed below it and a geogrid at the top.

The disadvantages of the known structures are:

- the impossibility of driving or crushing metal sheet piles due to the presence of reinforced concrete and metal buried objects in the soil;

- dynamic effects when driving piles on nearby existing buildings and structures;

- high cost for the installation of bored piles;

- the impossibility of installing on the site between the existing building and the excavated excavation pit powerful equipment used for the construction of bored piles;

- sheet piling serves as temporary structures for the period of excavation of the pit and the construction of the underground part of the building.

The objective of the utility model is to increase the efficiency of protecting buildings and structures from being excavated near the foundation pit, as well as reducing the cost of work.

The problem is solved by a reinforced soil-cement wall to protect buildings and structures from being excavated near the foundation pit, made in the form of a single soil-cement reinforced array, including non-recoverable metal injectors in the form of pipes with a diameter of 32-76 mm, consisting of a blank, perforated part and an edge, hammered into pre-drilled holes a grid of staggered wells, some of the injectors inserted under the foundation of the building to be protected, and all injectors tied by welding at the surface level of the earth with a steel bar with a diameter of 10–20 mm, and injected cement mortar was introduced into the soil under load under them.

According to the utility model:

- a reinforced soil-cement wall occupies the area between the building to be protected and the side of the excavated excavation pit, as well as a part of the area under the base of the building to be protected, the depth of the cement-wall being determined by the depth of entry of the injectors into the soil and exceeding the foundation pit by at least 200 cm;

- the load is natural soil or a special plate;

- the perforated part of the injector starts from the bottom of the foundation of the building to be protected, and the deaf part is equal to the height of the foundation;

- in one well there are several injectors of various heights, designed for cementation of different layers of soil, and the perforated part of each subsequent injector is located below the perforated part of the previous one, without blocking it;

- wells drilled vertically and / or inclined;

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

- wells are located in no less than 3 rows;

- the cement slurry injected into the injectors consists of cement and water, and 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 it.

The essence of the utility model is illustrated by drawings, which show the inventive reinforced soil-cement wall to protect buildings and structures from being dug near the foundation pit:

figure 1 - arrangement of wall injectors in the thickness of the earth;

figure 2 - arrangement of injectors, top view.

The reinforced soil-cement wall contains non-removable metal injectors 1. Position 2 denotes the protected building, position 3 denotes the side of the excavated near the foundation pit, position 4 denotes the reinforced cement-reinforced massif.

The construction of a reinforced soil-cement wall is as follows.

At the first stage of the work, the grid is marked out for the wells, their drilling and subsequent driving of injectors 1. The marking is carried out according to the natural topography, at a distance of 50-70 cm from the side 3 of the excavated foundation pit. Wells can be drilled vertically, obliquely or have a beam divergence depending on the purpose of the cement wall.

First create a barrier row of injectors. Behind the barrier row, injectors 1 are driven into pre-drilled wells. The size of the mesh depends on the composition and properties of the soil. After driving all injectors 1, they are strapped with a round steel bar (not shown). The strapping is performed by welding a steel bar with the body of the injector 1.

Then injected cement mortar is injected into the injectors 1. Injection solution is injected into the barrier row injectors first of all, and in a more viscous consistency with the use of quick-hardening additives, which allows you to create a screen that prevents the injection solution from breaking outside the cemented area, and gives tangible savings in consumables.

When two or three injectors are installed in one well, intended for alternately cementing two or three zones at different depths, the perforated part of each of them is located below the perforated part of the previous one, without blocking it. In this case, when installing two 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 accurate spreading of the injection solution in each of the reinforcement zones ( cementation) in depth. Cementation of soil zones in depth is carried out in stages - downward or ascending (from a shorter injector to a longer one or vice versa).

In terms of area, cementing work is carried out by a gradual rapprochement, starting with the maximum distances between the injectors, at which the hydraulic connection between them is practically absent during injection of the solution. In case of complication with the injection of the design quantity of solutions, the injection solution is fed into the cementation zone through each injector in stages, creating a layered soil-cement compound in the cementation zone. As a result, a soil-cement reinforced massif 4 is formed.

The number of rows of installed injectors should not be less than 3. Injectors in rows are staggered.

Soil strengthening is carried out under the load created by overlying natural soils, the body of the structure or a special plate. Weight, deformation properties, bearing capacity and permeability of the loading layer should ensure cementation at the design pressure of the mortar without violating the continuity of the loading layer and without leakage of cement mortar to the surface or to the loading layer. Cementation is carried out under a working pressure of 5-15 atm.

At the end of the cementation work, the aboveground part of the injector is cut off and filled with a cement plug.

The utility model is illustrated in tables 1-3, which show examples of the application of the proposed technical solution for specific objects (3 objects).

Table 1. Characteristics of soils at each of the facilities and types of work to strengthen them. Property 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 in order to exclude the impact on the dwelling house of the excavated foundation pit for the construction of an administrative building with an underground parking lot. Pit depth 8-10 meters Cement, water, liquid sodium glass. 2 Landslide, subsidence soils and sulfate-carbonate karst (loam), clay. Soil strengthening in order to exclude the impact on the dwelling house of the excavated foundation pit for the construction of an underground Water-cement solution containing liquid potash as an additive

parking lot. Pit depth 7 meters glass. 3 Sulphate-carbonate karst, landslide processes, loams, clays. Soils are waterlogged. Strengthening the soil in order to exclude the impact on the dwelling house of the excavated foundation pit for the construction of the building of a fitness center .. The depth of the pit is 10 meters Water-cement mortar with liquid sodium glass and bentonite clay. Table 2. Object No Deformation modulus, MPa specific adhesion, MPa porosity coefficient angle of internal friction, degrees density. s / cm3 one 10-15 0,023-0,031 0.78-0.087 16-19 1.88 2 13 0,03 eighteen 1.94 3 17 0,030 eighteen 1.94 Table 3. Property Number deformation modulus
MPa specific adhesion, MPa porosity coefficient angle of internal friction, degrees density, g / cm3 one 15-27 0,036-0,053 19-20 2.2 2 thirty 0.06 24 2.06 3 thirty 0,050 21 2,036

From the tables it follows that as a result of the application of the utility model in the cultivated soil, a reinforced cement-cement wall is created with enhanced physical and mechanical properties.

The work performed using the utility model showed that there was no settlement of existing buildings at any of the objects. The sides of the pit did not crumble and before the end of construction had the appearance of a glass-earth surface.

The construction of a soil-cement reinforced wall is environmentally friendly, the equipment for the production of works does not carry out harmful emissions into the atmosphere, since it works from electric power supplies. Production is almost waste-free.

The construction of a reinforced cement-reinforced wall is possible on almost all types of soils: rocky and semi-rocky at the base of buildings and structures, including in the slopes of foundation pits, karst, incoherent (sand, gravel, gravel), bulk and subsidence.

As a result of the application of the utility model, an almost homogeneous cement-cement structure (wall) with high bearing capacity is created. The reinforced soil is a new technogenic massif, consisting of natural soils, inclusions of cement stone, other components introduced into the ground and non-recoverable steel injectors, which are vertical elements of reinforcing the technogenic massif, which together with the ground structure forms a single spatial structure with high distribution and bearing capacity . Reinforced cement-cement wall replaces expensive enclosing structures (tongues from bored piles), which gives tangible savings in the construction of buildings and structures.

Thus, the application of the utility model allows to increase the efficiency of protecting buildings and structures from being excavated near the foundation pit, as well as reduce the cost of work.

Claims (9)

1. Reinforced soil-cement wall to protect buildings and structures from being excavated near the foundation pit, made in the form of a single soil-cement reinforced array, including non-recoverable metal injectors in the form of pipes with a diameter of 32-76 mm, consisting of a blank, perforated part and an edge, hammered into pre-drilled holes a grid of staggered wells, with some of the injectors inserted under the foundation of the building to be protected, and all injectors are tied by welding at ground level to steel m rod diameter of 10-20 mm, and through them into the ground under prigruzami introduced injectable grout. 2. The reinforced soil-cement wall according to claim 1, characterized in that it occupies the area between the protected building and the side of the excavated excavation pit, as well as part of the area under the base of the protected building, the depth of the cement-cement wall being determined by the depth of entry of the tip of the injectors into the soil and exceeding the depth of the excavation not less than than 200 cm. 3. Reinforced cement wall according to claim 1, characterized in that the load is natural soil or a special plate. 4. The reinforced soil-cement wall according to claim 1, characterized in that the perforated part of the injector starts from the bottom of the foundation of the building to be protected, and the deaf part is equal to the height of the foundation. 5. The reinforced soil-cement wall according to claim 1, characterized in that in one well there are several injectors of different height, designed for cementation of different depth layers of soil, and the perforated part of each subsequent injector is located below the perforated part of the previous one, without blocking it. 6. Reinforced cement wall according to claim 1, characterized in that the wells are drilled vertically and / or inclined. 7. Reinforced cement wall according to claim 1, characterized in that each injector is fixed in the well by a packer, which can be either surface or deep. 8. Reinforced cement wall according to claim 1, characterized in that the wells are located in at least 3 rows. 9. The reinforced cement-cement wall according to claim 1, characterized in that the cement mortar injected into the injectors consists of cement and water, and cement dust and water glass, or cement dust, bentonite clay and water glass, or cement dust are added to it. , fine sand and water glass, or water glass.