Pile and method of its installation into permafrost soil

FIELD: construction.

SUBSTANCE: pile comprises a hollow tubular case with an open lower end and an expander attached to the outer wall of the tubular case. The expander is fixed at the level of the open lower end of the tubular case and is made in the form of a spatial curvilinear structure, the section of which with a geometric plane passing via the vertical axis of symmetry of the tubular case is a trapezoid with bases. All points of trapezoid bases lie on spatial surfaces formed by displacement of trapezoid bases along parametric curves.

EFFECT: provision of vertical submersion of a pile with account of its bearing capacity.

10 cl, 8 dwg

 

Group of inventions relates to oil and gas construction, to the field of construction of load-bearing Foundation structures by immersing the tubular anchor piles and is designed to create a pile foundations and regulation of their impact on soil substrates in the construction of buildings and structures for various purposes in the areas of distribution of permafrost) with preservation of the base soil in its natural state throughout the life of the building or structure.

The term "territory permafrost or permafrost zone" includes the established concept meaning the region of the lithosphere, where the soils are frozen in the state continuously for more than a few (3-5) years.

The main problem of the construction of pile foundations of the industrial type within the permafrost zone is significant heterogeneity strength characteristics of soil under both plan and section. For these areas are also characterized by significant variability in soil temperatures geotechnical section formed by the heat exchange conditions on the Earth's surface. Mechanical properties of permafrost soils is mainly determined by their temperature, and the amplitude of these changes is that the same composition g the boots at different temperatures can be a liquefied mass of type "sour cream", and to have pronounced plastic properties on the type of "clay"and be a "rocky ground 5 categories. Such soils can be found even within the building footprint of individual buildings or engineering structures.

Particularly difficult conditions associated with the inaccessibility of the territory of permafrost, poor transportation and building infrastructure make particularly relevant to the application of the uniform (the same) on design of piles and unified way of their dives, which can be implemented in any soil conditions with guaranteed results to ensure the required bearing capacity. In this sense, screw piles are extremely promising for use, as they provide due to anchoring in the ground a significant reliability piles on the carrying and pulling loads. However, screw piles are not widely used in North construction, since the strength properties of permafrost soils require the use of technical means (machines and equipment), with significant torque to overcome the resistance of the soil when submerged piles. Used to date building mechanisms allow you to load screw piles, but the design of the piles which should be "adapted" under the strength characteristics of the Foundation soil. So, for example, pipe thawing of soils can be manufactured and shipped with a fairly significant amount (up to 800 mm) diameter screw part. The most common design - single-coil anchor. Piles, designed for immersion in permafrost soil have a greater angle of inclination of the spiral, a greater number of "turns" anchor part, but considerably smaller than the diameter of the anchor. Yes, they can be immersed without specialized equipment, but their bearing capacity and resistance against frost heave is significantly lower.

Known screw pile (RF patent for useful model №49841), comprising a hollow barrel with a support element and ribs on its upper end and a screw blade on the outer surface of the lower part of the trunk. The lower part of the trunk made in the form of cast tip connected with the upper part of the barrel by welding, on the inner surface of the handpiece is made of an additional blade and the lower end of the handpiece is made conical and is provided on the end face of the teeth. Dive screw piles as follows. Pile by screwing plunges into the top hole of a diameter equal to the diameter of the trunk. Reaching talus in the borehole, additional helical lobe moves the soil talus to the top of the barrel. Optional screw love the TB has 1.5-2 turns, this additional width of the blade is 0.15-0.25 from the inner diameter of the tip.

The result achieved when using the aforementioned construction, as described, is to facilitate the process of immersion through the facilities of the leader of the well and through the drilling of additional ground blade from the inner cavity of the pile. "A significant increase" bearing capacity of the pile is achieved by increasing the area of the projection of additional screw on a plane perpendicular to the axis of the pile, which in turn can be estimated by the value of 1.5-2.0% when using the blade size of 0.25 dint. The above suggests that to obtain the desired (design) bearing capacity and stability of the piles in this way is problematic because "the range of regulation of the bearing capacity and stability" does not exceed a few percent.

There is a method of immersing the tubular piles in permafrost soil (RF patent for the invention №2199627), including the rotation of the pile with the formation of the annular heating zone with simultaneous axial direction of the pile with the application of a pressing load, characterized in that the axial pile regulate the ratio

where h is the axial feed, mm/Rev; P is the axial force, kN; f - coefficient of friction with the Ali on the ground; k is thermal equivalent of the work, Kal/KGM; k1- specific heat of ice, cal/g·deg; t0the temperature of the frozen ground, °C, k2- heat of ice fusion, cal/g; q is the specific weight of ice, g/mm3; kLis the coefficient of listorti frozen ground; δ - thickness of the wall of the dip pipe, mm; δ' - end extension plane of the zone of friction due to radial beating the end of the pipe, mm

The method allows you to immerse in the soil of the tubular pile with smooth walls, without anchoring device, as represented by a numerical value describes the equality of heat due to friction forces end piles on the ground and cost of heat for heating and melting" permafrost soil in the annular zone at the lower end of the pile allocated for one revolution of the rotor mechanism to dive, taking into account the volume occupied by the pile wall (including beatings), immersion h mm per revolution. Any anchoring device is placed on the lower end of the pile, will require large amounts of heat, as in the implementation of immersion will need to form a" ring melt zone of larger diameter than mentioned in the claims. Also the disadvantages of this method include the inability of the pile with the anchor element.

Closest to the technical nature of the claimed group of inventions I is comprised of construction of the tubular piles with a protective coating and method of immersion in permafrost soil (RF patent for the invention №2202680). The hollow tubular body is made with an open bottom end, the outer wall of the tubular body at the level of the lower border of its protective coating provided by the extender, made in the form of a straight triangular prism whose bases are right triangles, with one of the edges of α each base plate is located on the generatrix of the tubular body, the other edge β of each of the base at right angles to it, and the values of edges α and β of the bases of the prism extender are determined from ratios,

where α, β are the dimensions of the straight edges of a triangular prism, m; V - speed immersion tubular piles, m/min; ω is the rotation speed of the tubular piles, rpm;- outer diameter tubular piles, m; Hn- the distance from the lower end of the tubular piles up extender, m;- density ottange soil, kg/m3; g - gravitational acceleration, m/s2;- coefficient of internal friction of the soil, ξ0- coefficient of lateral friction of the soil, LV- heat of melting per unit volume of frozen soil, j/m3, δpokr- coating thickness, m immersion tubular piles with a protective coating in permafrost soil involves the simultaneous impact on the tubular pile steep is the future of moment and axial force to education in the soil under the end of the tubular piles and along its walls octanol zone in the form of a hollow cylinder and the depth in her tubular piles. In the process of immersion tubular piles along the walls in the interval from the surface to the bottom edge of the protective coating creates a zone of ottange soil thickness is greater than the thickness of the zone ottange soil along the walls of tubular piles below the protective coating is not less than the thickness of the protective coating.

Known solution allows you to immerse tubular pile with the extender in the form of a straight triangular prism by rotating the pile with the formation of the annular heating zone below the lower end and below the expander. The disadvantage of the above method is that the target function method does not use the extender as anchor device after the pile into the soil and restore the natural temperature of the permafrost. The extender is used only to ensure the safety of the insulating coating within active seasonal soil layer near the upper end of the pile.

The task, which directed the claimed technical solution is the creation of a unified design of anchor piles, buried in the ground, while using a minimum number of technological operations, the minimum number and types of construction equipment, providing the possibility of obtaining a given (design) carrier SPO is oblasti and resistance against the forces of frost heave by changing the geometric parameters of the piles. Also a problem is the creation of a method of installation of piles, ensure immersion piles in soils with any found in developed areas of permafrost mechanical properties.

Technical result achieved when using the claimed group of inventions is to provide a vertical pile with regard to its bearing capacity.

The problem is solved in that in the pile, comprising a hollow tubular body with an open bottom end and an extender attached to the outer wall of the tubular body, according to the technical solution of the extender attached to the open lower end of the tubular housing and is designed as a spatial curved design, the cross-section of a geometric plane passing through the vertical axis of symmetry of the tubular body, represents a trapezoid with bases α and β, with all points of the bases of the trapezoid lying on spatial surfaces formed by the movement of the bases of a trapezoid on parametric curves:

;;and

;;where

xα, yα, zα- spatial coord. who are you to point the surface of the extender, the described lower base line;

xβ, yβ, zβspatial coordinates for points on the surface of the extender, described the upper base of the trapezoid;

ddrug- outer diameter of the tubular body, m;

Lraces- the length of the projection of the height extender on the axis of symmetry of the tubular body, m;

hTr- the height of a trapezoid, m;

φ∈[0, φmax] is the parameter describing the rotation angle of the axial plane of the extender, I'm happy.;

φmax- maximum absolute value of φ, rad.;

δ is the wall thickness of the tubular casing, M.

Numerical values of α and β selected from the rangesand β∈[0, α] with the possibility of a given strength characteristics of piles. The sides of the trapezoid can be a concave curves. Numerical values of ddrugthat & Phi;max, δ, hTr, Lracescan be selected from the following ranges:

ddrugfrom 0.1 to 0.4 m;

δ - 6 to 12 mm;

hTr- 0.0·ddrugto 1.5·ddrug;

φmax- from 0 to 100π;

Lracesfromto

with the possibility of providing and regulating the design bearing capacity of the pile and its resistance to the forces of frost heave in accordance with the following ratios:

<> ;

for pressing load and

for pulling, where

Fd,du- bearing capacity of the piles, TC;

γi- reliability: γaf- coefficient depending on the type of surface freezing, γcthe reliability coefficient from the piles, γt- temperature coefficient;

R - specific calculated resistance frozen ground normal pressure, TC/m2;

Rsh- specific calculated resistance permafrost soil shear on the surface of the freezing ground, TA/m2;

Raf,i- current resistance of the frozen ground offset side surface freezing tubular casing piles with permafrost soils, TA/m2;

Aaf,ithe surface area of freezing the i-th soil layer with a lateral surface of the tubular casing piles, m2. The pile can also be equipped with the baking powder, attached to the expander side of its lower end surface and is made in the form of a shape, the shape is close to a triangular pyramid, with at least one curved face, and the base of the pyramid is located on the lower end surface of the extender, the curvature of the curved face of the pyramid corresponds to the curvature of the tubular body, and the height of the pyramid hPR set in the range of values from 0.6 hTrto 1.8 hTrwhere hTr- the height of a trapezoid, m Plot tubular casing piles, located between the area of the lower end surface of the expander and the lower end surface of the pile is a truncated cone, with curved faces of the pyramid baking powder is made curved in the form of the helical pattern of the screw and the top of the baking powder is located on the generatrix of the truncated cone near the lower end of the tubular housing. The task is also solved by the fact that in the method of installation of piles, including the drilling of the top hole with a diameter smaller than the inner diameter of the hollow tubular body piles, installation of piles leader in the borehole, the simultaneous effect on the pile of torque and axial force to pile on the project depth, filling the internal cavity of the piles of cement-sand mortar, ofanim drilled soil or other dirt or sand-cement mortar and exposure of the latter to its freezing with an array of permafrost, according to the technical solution process simultaneous effect of torque and axial forces achieve axial equal the value offor one revolution of the rotor rotating mechanism by alternating from the change of torque and axial forces, where

Lraces- the length of the projection of the height extender on the axis of symmetry of the tubular body, m;

φ∈[0, φmax] is the parameter describing the rotation angle of the axial plane of the extender, I'm happy.;

φmax- maximum absolute value of the parameter φ describes the rotation angle of the axial plane of the extender, I am glad. Before installing piles on the wall of a leader well have heat until a temperature of the beginning of the thawing permafrost soil.

Alternatively, the task is claimed a method of installation of piles, including the drilling of the top hole with a diameter smaller than the inner diameter of the hollow tubular body piles, installation of piles leader in the borehole, the simultaneous effect on the pile of torque and axial force to pile on the project depth, filling the internal cavity of the piles of cement-sand mortar, ofanim drilled soil or other dirt or sand-cement mortar and exposure of the latter to its freezing with an array of permafrost, while, according to the technical solution, in the process of simultaneous effects of torque and axial force at the termination of the dive piles take axial load and remove the pile from the soil through the application thereto oppositely napravlennoj the torque then resume the simultaneous influence of torque and axial force with increasing speed of rotation of the mechanism used for dipping, while delivering the thawing of the soil beneath the lower end surface of the pile and around its lateral surface with the formation of octanol annular zone, an outer radius which is not less than. When resuming impact provide the specified performance of the pile, setting the axial flow in accordance with the following relationship:

where

η - axial feed piles into the ground, m/s;

Qf- specific heat content of the thawing of the soil, j/m3;

f - coefficient of friction between the pile and the soil surface;

Pc- the pressure of the pile at the ground surface, PA.

The claimed group of inventions is illustrated by the following drawings.

Figure 1 presents an image of piles installed in the ground.

Figure 2 is a schematic representation of a section of tubular casing piles with the extender, the vertical cross section in which each point represents a line.

Figure 3 is a schematic representation of the morphology of the expander in the form of a trapezoid.

Figure 4 is a schematic representation of the morphology of the expander in the form of a rectangle.

In Fig. a schematic representation of the formation of the expander in the form of a triangle.

Figure 6 is a schematic representation of the morphology of the expander in the form of a triangle (a degenerate trapezoid) with concave sides.

7 is a schematic representation of the morphology of the expander in the form of a trapezoid with pyramidal baking powder, secured on the lower end surface of the extender.

On Fig presents a plot of the tubular casing piles, made in the form of a truncated cone.

Positions on the drawings indicated:

1 - pile, 2 - tube case, 3 - extender,4 - baking powder.

Pile (1) is a tubular metal structure, comprising a tubular housing (2) and the expander (3), e.g. made of steel. The tubular body (2), piles made in the form of a hollow cylinder with open upper and lower end and the wall thickness δ. Near the lower end of the tubular body (2) piles (1) on its external surface is rigidly fixed to the expander (3), for example, by welding or casting, made in the form of a curved spiral shape, encircles the tubular body (2) piles (1) with a length Lraces. The number of complete rotations of the expander (3) around the tubular body (2) is equal to φmax. The cross section of each section of the expander (3) a plane passing through the axis of symmetry of the tubular body (2), in the General case is a trapezoid, OS is Finance which (α and β) parallel to the axis of symmetry of the tubular body and can be powerlineman in the range of values of and β∈[0, α]. The sides of a trapezoid can be made in the form of direct and concave lines, with the concavity directed into the line. The sizes of the bases of a trapezoid are selected so that, on the one hand, to provide equivalent strength characteristics of separate parts of the pile as a single structure, while the simultaneous fulfillment of the requirements for reducing the resistance to cutting of soil by baking powder when submerged piles, to ensure the developed surface friction of metal on the ground to ensure the formation of annular melt zone around the outer and inner surfaces of the tubular body (2), and on the other hand, to provide a sufficient area of the expander (3) piles (1) in permafrost soils after restoring their natural temperatures. On the outer surface near the lower end of the tubular body (2) butt joint with the lower end of the trapezoidal surface of the expander (3) can be fixed baking powder (4), from a geometrical point of view represents a pyramidal structure, the base of which is placed on the end of the trapezoidal faces the surface of the expander (3), and one of the side faces of baking powder (4) is made curved, and the curvature of this edge corresponds to the curvature of the tubular body (2).

The lower part korpusnoe to be made in the form of a truncated cone or a direct cylinder.

Regulation bearing capacity of the pile and its resistance to the forces of frost heave is achieved through informed choice of the numerical values of the geometric parameters of the tubular casing ddrug, δ and extender φmaxhTrL from a range of values

ddrugfrom 0.1 to 0.4 m;

δ - 6 to 12 mm;

hTr- 0.0·ddrugto 1.0·ddrug;

φmax- from 0 to 100 π;

Lracesfromto;

before getting into specific ground conditions design values of the forces pressing and pulling the load, taking into account design factors "reliability".

An example of regulation of the bearing capacity of piles

Engineering-geological cross-section of the considered construction site presented within the active layer to 1.6 meters loam glacial (i=0,40), slightly saline (Dsal=0,77), with average temperatures at the time of the maximum (1.6 m) thawing t=+0,4°C. Next, to a depth of 4.0 m sandy loam, ice content i=0.25, the salinity of Dsal=0,24, temperature t=-2,3°C. With a depth of 4.0 m and below the incision sandy loam labeldata (i=0,16), non-saline (Dsal=0,06) with temperature t=-2,4°C.

The area is laid pile Foundation, which would have taken the load from the structure, is equal to Fwdwlive=18,0 TS on a single CBA is. This level of stress is most typical for foundations of frame industrial buildings, complex processing pipeline bindings, private foundations technological equipment. Used as a tubular casing piles of metal pipe length L=6.0 m, with a diameter of ddrug=0,219 m and wall thickness δ=0,008 m

Pile Foundation, while providing a perception of design load should "protect" the construction of seasonal deformation of the piles under the influence of frost heave, equal, to consider engineering and geotechnical conditions, the value of Fvidel=12,9 TC.

In accordance with SNiP 2.02.04-88 coefficients of reliability equal to γaf=0,7 (coefficient depending on the type of surface freezing), γc=1,0 (reliability coefficient on the work piles), γt=0,8 (temperature coefficient); the calculated values of specific resistance of the frozen ground normal pressure in the cu/m2(R), nominal design impedance of permafrost soil shear on the surface freezing from permafrost soil in cu/m (Rsh) and the calculated resistance of the frozen ground offset side surface freezing tubular casing piles with permafrost soils in the TS/m2(Raf,i) calculated SNiP 2.02.04-88 and is shown in the table.

The height of the line extender is selected in the range of absolute values close to the minimum limit, such as hTr=0,04·ddrug=0,219·0,04=0,008 m; the size of its grounds α=β=δ=0,008 m Length extender Lraces=0.40 m provides φmaxequal to 720°, that is, (φmax=4π).

The total surface area of freezing within two permafrost layers geotechnical section (line 2 and 3, table 1) is equal to(layer 1 is not frozen, it is seasonally thawing).

When this area of the freezing side surface of the casing piles of soils within each geological element (layer) is equal to Aaf,1=0.55 m2(the breed gets frozen with the surface of the piles within the layer of seasonal thawing),and

respectively.

The forces keeping the pile in the soil due to their freezing her body, equal out the location of the extender:

Force opposing the displacement piles down vertically due to the application of loads from advancement design:

Force opposing the displacement piles up along the vertical axis due to frost heave of the soil of the seasonally thawing layer:

Force, arrivalsa the pile in the soil due to the extender and the action of forces, preventing the mixing of the dilator along the axis of the pile:

In the end, taking into account factors of reliability pile proposed design has a total carrying capacity by pressing the load equal to:

and is resistant provisions against the effects of pulling load:

Thus, the pile with selected characteristics (ddrug=0,219 m, φmax=4π, δ=0,008 m, hTrvalue =0.008 m, Lraces=0.40 m) does not provide design parameters by pressing load. Requires the regulation of the geometric parameters of the extender to ensure the designed performance.

However, the absence of extender per se leads to the following results. Consider the bearing capacity of piles in ddrug=0,219 m, φmax=4π, δ=0,008 m, hTr=0,0 m, Lraces=0,0 m

In this case, compared with the previous example, the value of F will increase by an amount corresponding to the forces of freezing body material piles of soils within the surface of the body, where you previously placed the extender

Other components of the bearing capacity of the pile is equal to:

In the end, considering what the factors of reliability pile without the extender has a total carrying capacity by pressing the load, equal to:

and is resistant provisions against the effects of pulling load:

Thus, the addition of a tubular casing piles very small extender increases by 35% of the bearing capacity of the pile and its resistance against the forces of seasonal frost heaving under other equal conditions (soil characteristics, the size of the piles etc).

The process of regulation of the bearing capacity is ensured by changing the geometric characteristics of the dilator within the specified ranges.

For example, in this case, an increase in h 20 mm, up to the value 0,028 m (0,13·ddrug) gives a positive result and total restraint of the pile forces increase to estimated values, namely

In the result, the total load-carrying capacity of the pressing load is equal to:

and is resistant provisions against the effects of pulling load:

The required design value by pressing the load is achieved. Characteristics of piles set equal to ddrug=0,219 m, φmax=4π, δ=0,008 m, hthe p =0.025 m, Lraces=0,4 m

The inventive method implemented as follows.

The main factor in the installation of piles is the provision of a certain axial vertical pile. Pre-Buryat leader of the borehole, the diameter of which is smaller than the inner diameter piles. The diameter of the leader of the wells selected from a range from 0 to ddrug-δ depending on the state of permafrost soils. The minimum diameter is used mainly for fine plastic-frozen soils, occurring at a temperature corresponding to the beginning of the transition pore moisture in the melt state, and the maximum for permafrost soils with a significant difference between the natural temperature of deposition and the onset temperature of thawing.

The pile of the claimed design installed in the top hole, then to the pile simultaneously applied axially (vertically located along the axis of symmetry of the hull piles) force and torque. At the same time provide the ratio of the applied axial load and torque to axial feed (speed dive) was equal to the value ofmeters per revolution of the rotor rotating mechanism by alternating changes of torque and axial forces. Prior to the installation of piles in the leader of the th hole on the wall of the latter may be provided to heat until the temperature reaches the beginning of the thawing permafrost soil. For thermal effects can be used any extended fuel source, such as a hose with holes in the side walls for supplying superheated steam, or heated mass drilled soil. Thus, while providing a specified axial pile immersed to the desired depth, after which its hollow body, if necessary, fill with sand and cement or other fixation solution and can stand up to freezing at ground level, then consider the installation is complete.

In the case when the dip pile in the process the simultaneous effect of torque and axial force is terminated, that is unable to provide the specified axial feed, the pile is extracted through the cessation of axial force and direction change of torque. After extracting piles on the surface of the resume simultaneous effects of torque and axial force with increasing speed of rotation of the rotary mechanism, used for dipping, such as installing KATO model PF-1200-YSVIII. However due to friction on the permafrost of the lower end of the tubular piles and the side surface of the extender provides the thawing of soil beneath the bottom end of the pile and around its lateral surface forming an annular zone, the outer radius of which exceeds an amount equal to the achieving the required performance of pile (axial) through the establishment of axial force in accordance with the following relationship:where

η - axial feed piles into the ground, m/s;

Qf- specific heat content of the thawing of the soil, j/m3;

f - coefficient of friction between the pile and the soil surface;

Pc- the pressure of the pile at the ground surface, PA.

Consider a specific example of implementation of the method of installation of piles. Metal pile with a total length of 10 m with the proposed design of the extender with the following geometrical parameters ddrug=0,325 m, φmax=4π, δ=0,008 m, hTr=0.03 m, Lraces=0.4 m, α=0,008 m, β=0,004 m Carry out immersion in icy tvercommertsia loam with a specific heat of thawing Qf=101136·103J/m3. For pile used self-propelled drilling rig KATO model PF-1200-YSVIII. Initially in the rotary mechanism of the rig fix the standard drilling tools with a diameter of 300 mm and perform the drilling leader of the well to the depth of the design position of the upper end of the extender. Next, the drilling tool is removed from the rotary mechanism and produce heating of the internal cavity of the leader wells steam needle until it reaches the temperature of the beginning of the faithful is the air traffic management breeds, composing the walls of the leader of the well. Such heating can translate in plastic-frozen state of the soil composing the walls of the well to a depth exceeding 50 mm To ensure uniform heating or when planning a long break between the drilling leader well and immersion piles may be used another method of heating, which consists in filling (fill) leader well rastoplenym drilled the ground, allowing you to keep plastic-frozen condition of the soil composing the walls of the well, over a long time. After warming up the walls of the bore in the rotary mechanism of the drilling machine set the pile, exert an axial force equal to, for example, 1/3 of the operating range of the hydraulic system KATO model PF-1200-YSVIII, with the simultaneous application of torque, while seeking alternate regulation of torque and axial forces provide axial pile equal tometer per revolution of the rotor of the drilling rig. Maintaining a steady flow, complete the pile to the design depth.

In the case when there is no possibility to establish and maintain the desired feed rate during the whole process of immersion due to insufficient operating range for axial loads and torque moments and is used for dipping mechanism, the immersion process is temporarily interrupted, relieve axial load and remove the pile from the soil through the application thereto oppositely directed torque. Next, after removing piles on the surface of the resume simultaneous effects of torque and axial force with increasing speed of rotation of the rotary mechanism of the drilling rig, while the desired performance immersion set predominantly axial force, providing the thawing of soil beneath the bottom end of the pile and around its lateral surface forming an annular zone, the outer radius of which exceeds an amount equal toThis size thawing in the loam (Qf=101136·103J/m3) provides, for example, when the axial force 12 TC (3/4 of the operating range of the hydraulic system of the drilling rig "Kato" is used in the model), that is, when the pressure on the ground the lower end of the body and the side surface of the expander, is equal to Pc=2950 kPa, when the value of the coefficient of friction of metal on permafrost fine soil (f=0.45, and axial flow (speed dive), equal to:

for one revolution of the rotary mechanism of the drilling rig.

The operating range of the rotor Kato model PF-1200-YSVIII provides from 0 to 54 turns in a minute. Overall time to dive under consideration piles can be estimated by the value of 10-25 minutes.

Average speed dive experimental piles, is a hollow tubular metal housing without the extender and without a leader well, on the subject "the pioneer Pipeline gas supply to the site of the industrial base HP Bovanenkovo amounted to approximately 1 m/min at a rotor speed of 15-25 rpm.

Thus the proposed device and method of installation allows to reduce time and material costs for construction of pile foundations in permafrost. Additionally, the device and methods are regional properties of universality, because it does not require changes in technology during the transition from plastic-frozen to tegmentum areas of permafrost merging type, applicable for areas recessed roof permafrost, stipulate the use of the technological cycle only one mechanism and minimizing the "wet process".

1. Pile, comprising a hollow tubular body with an open bottom end and an extender attached to the outer wall of the tubular body, characterized in that the expander is attached to the open lower end of the tubular body and is made in the form ol the spatial curvilinear designs, section a geometric plane passing through the vertical axis of symmetry of the tubular body, represents a trapezoid with bases α and β, with all points of the bases of the trapezoid lying on spatial surfaces formed by the movement of the bases of a trapezoid on parametric curves:
and

where xα, yα, zα- the spatial coordinates of the surface points extender described lower base line;
xβ, yβ, zβspatial coordinates for points on the surface of the extender, described the upper base of the trapezoid;
ddrug- outer diameter of the tubular body, m;
Lraces- the length of the projection of the height extender on the axis of symmetry of the tubular body, m;
hTr- the height of a trapezoid, m;
φ∈[0, φmax] is the parameter describing the rotation angle of the axial plane of the expander, glad;
φmax- maximum absolute value of φ, rad;
δ is the wall thickness of the tubular casing, M.

2. Pile according to claim 1, wherein the numerical values of α and β selected from the rangesand β∈[0,α] with the possibility obespechitelnyh strength characteristics of piles.

3. Pile according to claim 2, characterized in that the lateral sides of a trapezium are concave curves.

4. Pile according to claim 1 or 2, or 3, wherein the numerical values of ddrugthat & Phi;max, δ, hTr, Lracesselected from the following ranges:
ddrugfrom 0.1 to 0.4 m;
δ - 6 to 12 mm;
hTr- 0.0·ddrug1.5·ddrug;
φmax- from 0 to 100π;
Lracesfromto
with the possibility of providing and regulating the design bearing capacity of the pile and its resistance to the forces of frost heave in accordance with the following ratios:

for pressing load and

for pulling,
where Fd,du- bearing capacity of the piles, TC;
γi- reliability: γaf- coefficient depending on the type of surface freezing, γcthe reliability coefficient from the piles, γt- temperature coefficient;
R - specific calculated resistance frozen ground normal pressure, TC/m2;
Rsh- specific calculated resistance permafrost soil shear on the surface of the freezing ground, TA/m2;
Raf,i- current resistance of the frozen ground offset side surface of the freezing trubo is the case piles with permafrost soils, TC/m2;
Aaf,i- the surface area of the freezing of the i-th soil layer with a lateral surface of the tubular casing piles, m2.

5. Pile according to claim 1 or 2, or 3, characterized in that it is provided with baking powder, attached to the expander side of its lower end surface and is made in the shape of the form similar to a triangular pyramid, with at least one curved face, and the base of the triangular pyramid is located on the lower end surface of the extender, the curvature of the curved face of the pyramid corresponds to the curvature of the tubular body, and the height of the pyramid hTrset in the range of values from 0.6 hTrto 1.8 hTrwhere hTr- the height of a trapezoid, m

6. Pile according to claim 5, characterized in that the section of the tubular casing piles, located between the area of the lower end surface of the expander and the lower end surface of the pile is a truncated cone, with curved faces of the pyramid baking powder is made curved in the form of the helical pattern of the screw and the top of the baking powder is located on the generatrix of the truncated cone near the lower end of the tubular body.

7. The method of installation of piles in permafrost soil, including the drilling of the top hole with a diameter smaller than the inner diameter of the hollow tubular body piles, is a stop piles leader in the borehole, the simultaneous effect on the pile of torque and axial force to pile on the project depth, filling the internal cavity of the piles of cement-sand mortar, ofanim drilled soil or other dirt or sand-cement mortar and restraint of the pile to its freezing with an array of permafrost, characterized in that in the process of simultaneous effects of torque and axial forces achieve axial equal to the value offor one revolution of the rotor rotating mechanism by alternating changes of torque and axial forces,
where Lraces- the length of the projection of the height extender on the axis of symmetry of the tubular body, m;
φ∈[0, φmax] is the parameter describing the rotation angle of the axial plane of the expander, glad;
φmax- maximum absolute value of the parameter φ describes the rotation angle of the axial plane of the extender, I am glad.

8. The method of installation of piles according to claim 7, characterized in that before installing piles on the wall of a leader well have heat until a temperature of the beginning of the thawing permafrost soil.

9. The method of installation of piles in permafrost soil, including the drilling of the top hole with a diameter smaller than the inner diameter of the hollow tubular cor the USA piles, installation of piles in the top hole, the simultaneous effect on the pile of torque and axial force to pile on the project depth, filling the internal cavity of the piles of cement-sand mortar, ofanim drilled soil or other dirt or sand-cement mortar and restraint of the pile to its freezing with an array of permafrost, characterized in that in the process of simultaneous effects of torque and axial force at the termination of the pile relieve axial load and remove the pile from the soil through the application thereto oppositely directed torque, and then resume the simultaneous influence of torque and axial force with increasing speed a rotation mechanism that is used for dipping, while delivering the thawing of the soil beneath the lower end surface of the pile and around its lateral surface with the formation of octanol annular zone, an outer radius which is not less than.

10. The method of installation of piles according to claim 9, characterized in that upon renewal impacts provide the specified performance of the pile, setting the axial flow in accordance with the following ratio:
,
where η is the axial feed of the pile into the soil, m/s;
Qf-specific heat content of the thawing of the soil, J/m3;
f - coefficient of friction between the pile and the soil surface;
Pc- the pressure of the pile at the ground surface, PA.



 

Same patents:

FIELD: construction.

SUBSTANCE: method for making well for rolled-screw pile including drilling of conventionally cylindrical well. Roller unit and step accessory are connected to auger, device rotation is actuated for thread rolling, roller unit is brought into well, and thread making is started with the help of three rollers with various diametres and thicknesses in the form of truncated cone each, which are serially rolled one after another, and soil is impressed into well wall with angle of thread inclination between plane, where large wheel of each roller is located, and axis of roller unit rotation, making 76 degrees. Master roller executes primary rolling of thread, then intermediate roller of larger diametre and thickness expands groove, increasing thread dimension, and shaping roller of larger size completes soil compaction into well wall and thread rolling. Pitch, which provides for step accessory on auger per single complete rotation of shaping roller equal to 360 degrees makes 0.67 d, where d is diametre of roller unit pipe, and thread pitch corresponds to pitch of single turn of auger blade. Step accessory operates only in process of thread rolling together with rolling unit, and thus thread is rolled for the whole depth of well, reverse rotation is started, and roller unit is brought upwards along shaped thread, afterwards well is inspected and concreted. Device for method realisation comprises auger for drilling of conventionally cylindrical well, device for thread rolling made of roller unit, auger and step accessory. Roller unit includes steel pipe with diametre d with slots for rollers, steel bushings for axles of rollers, master roller with diametre of 0.52 d, intermediate roller with diametre of 0.71 d, shaping roller with diametre of 0.83 d, cover with tail, bottom. All three rollers are arranged as steel and are shaped as truncated cone, and straight line that coincides with diametre line of large wheel in each roller, crossing axis of roller unit rotation, is perpendicular to generatrix of pipe cylindrical surface in point of their crossing, and plane of each roller fit, i.e. plane of roller unit rotation axis crossing with point of crossing of roller rotation axis and large wheel of roller are at the angle of 120 degrees to similar plane of fit of each of two rollers.

EFFECT: simpler, affordable and cheaper arrangement of well for rolled-screw pile of high bearing capacity with the help of facilities for well drilling.

7 cl, 5 dwg

FIELD: construction.

SUBSTANCE: device for screwdriving of piles is related to construction and may be used for erection of bearing foundations, fixation of various mechanisms and devices on soil, also under conditions of frozen soils in process of screwdriving of metal tubular piles. Device comprises spinner 1, reducer 2 and cartridge 3, which is arranged in the form of bushing with longitudinal slot and horizontal axis. Lower part of cartridge 3 is equipped with grips with handle and spring-loaded fixator, besides grips have dead slots. Horizontal axis is made with cylindrical protrusions at ends, and longitudinal slots of bush are arranged as stepped and closed. Device may additionally be equipped with the second horizontal axis, detachable pad made of two plates, in which holes are arranged for horizontal axes, at the same time in one of plates holes are made with figure shape, and at one end of horizontal axes there are slants arranged with similar figure shape.

EFFECT: invention makes it possible, due to reduction of time for pile preparation for lift, its fixation in cartridge, to significantly increase efficiency of works on piles driving, and also to improve conditions of work, since all works are carried out not at height, but on ground, in close proximity to area of pipe screwdriving.

2 cl, 10 dwg

FIELD: construction.

SUBSTANCE: invention concerns bored pile construction in any soil environment, and can be applied in industrial and civil construction for construction of new foundations and reinforcement of existing ones, as well as in construction of supports bearing alternate loads. Method involves well drilling by drilling assembly consisting of drilling column and rock crusher, filling the well with solidifying mix, drilling column extraction from well, downtake of metal frame. Well drilling is performed with crushed rock discharge to surface by flush liquid or compressed air fed to bottomhole through hollow drilling column. Simultaneously with well drilling, metal frame made of reinforcement rods with helical flange at external surface is taken down by rotation. Frame is mounted coaxially along drilling column and can rotate together with it. Drilling column is extracted from well together with rock crusher, along with uninterrupted filling of well with solidifying mix through hollow drilling column.

EFFECT: enhanced efficiency of bored pile construction, improved manufacturing quality, enhanced life time and strength of pile.

4 cl, 3 dwg

FIELD: construction industry.

SUBSTANCE: method of installing tubular pile in permanently frozen earth involves rotation of pile and its simultaneous vertical movement under influence of pressing axial load applied to the pile. At that speed of vertical pile movement Vm, value of pressing axial load Pt and angular speed of pile rotation ω are controlled using a nomogram built in logarithmic coordinate system wherein along x-axis there marked are magnitudes of the value (athth) that comprises the ratio of thermal conductivity of thawed earth ath to thickness of thawed earth seam under pile edge δth, and along y-axis there marked are values of speed of vertical pile movement Vm. Nomogram consists of two families of Vm-vs-(athth) curves based on calculations of thermal, mechanical and hydrodynamic processes when installing the pile. The above nomogram provides the possibility of choosing the speed of vertical pile movement Vm, depending on pile size and specific earth properties, when Pt and ω are available, as well as the possibility of choosing pressing axial load Pt and angular speed of pile rotation ω when Vm and ath, δth are available.

EFFECT: improving the accuracy of parametrisation of pile installation mode.

3 cl, 2 dwg

FIELD: construction, methods or apparatus for placing sheet pile bulkheads, piles, mould-pipes, or other moulds by screwing down, namely for electric plant mounting.

SUBSTANCE: device comprises frame, guiding pipe with clamp, reduction gear with gear-wheels and bearings. Guiding pipe, driving gear-wheel and bearings are made as two sectional parts and provided with hinges from the first sides and with locks from the second sides thereof to join up all parts in single rigid structure. All hinges are coaxially arranged.

EFFECT: extended field of screw grounding electrode usage during grounding devices installation, increased structural simplicity, decreased weight and costs, increased reliability and operational safety, possibility of device usage in the case of power source absence or in territories unsuitable or unfavourable for another equipment usage.

3 cl, 3 dwg

FIELD: building, particularly to erect load-bearing foundation, to retain installation on ground surface and to drive underwater and ground-surface tunnels.

SUBSTANCE: screw pile comprises metal pipe with helical winding formed on the metal pipe and with concrete head installed on the pipe. Concrete head has thickness equal to 1/4-5 pipe diameters. Metal rods having length equal to that of concrete head are built in the concrete head. The helical winding extends along the full shaft length and is made as helical blade with width equal to 0.5-5 concrete head diameters. The helical winding has conical part formed in lower pile part and extending for the length equal to not more than 1/3 of pile length. Triangular stiffening ribs are distributed over the full helical blade surface and have bases connected with each other and abutting metal pipe. Apexes of the stiffening ribs are located at blade edge. Apex of each stiffening rib is provided with metal rod. Metal rods of stiffening ribs are connected with each other by metal reinforcement members embedded in blade edge. Additional triangular stiffening ribs are created in the blade. The additional triangular stiffening ribs extend transversely to main stiffening ribs and have bases connected with pipe. Additional stiffening ribs have apexes fastened to apexes of corresponding main stiffening ribs. Connection member adapted to connect the screw pile with building structure is located in upper pipe part. The connection member is made as header provided with thread or ribbed reinforced concrete header. Upper part of the header is fitted with hook fixer. Lower part thereof has bolt to provide keyed pile driving means fixation. Screw pile driving method and means, as well as tunneling method or method for underground passage construction by open-cut method with the use of the screw pile are also disclosed.

EFFECT: increased structural load-bearing ability, simplified structure, accuracy and reliability of screw pile driving, as well as possibility to drive pile in densely built-up areas.

5 cl, 7 dwg

FIELD: building, particularly screw pile forming.

SUBSTANCE: device comprises body, drive with load-bearing unit having outer collar joined with the body through worm gearing and inner collar joined with hollow screw working tool, which is provided with screw extensions made in lower end part. The device also has orifice for releasable valve receiving and to discharge well-filling materials into the well. Bunker is formed from upper end of working tool. Inner collar made in leading unit of the drive is joined with working tool to transmit rotation force to any working tool part through sliding connection. Inner and outer leading unit collars are connected to form the first pair. Inner collar of leading unit and working tool are coupled to form the second pair. The body and the working tool are connected by controlled fixers to constitute the third pair. The controlled fixers specify direction of mutually connected pairs in joint areas along the whole area of possible joint of each member pair. Power equipment of the drive may transmit translational and rotary movement to leading unit of the drive along with screw line pitch and operational direction specified during device operation. Cleaning unit, which removes foreign objects from outer surface of working tool is connected to inner collar of the leading unit.

EFFECT: reduced time of composite working tool reassembling and increased tool capacity.

5 cl, 5 dwg

FIELD: building, particularly for hole drilling in stable sedimentary rocks during building concrete and reinforced concrete piles having high load-bearing capacity and adapted for foundation and anchoring support forming.

SUBSTANCE: device has immovable unit fixed relative ground during drilling operation and installed on vehicle, and movable unit moving over immovable part for hole drilling. Immovable unit has steel tubular body closed with steel caps from both sides thereof. Four guiding channel bars and two threaded bars are arranged inside the tubular body. Movable unit has drilling shaft including threaded drill made as steel tube with two differently sized cutters. The cutters are of dihedral shape and have common rib and orifices formed in the steel tube under the cutters. Area of ground cut by lesser cutter is twice as small as that cut by larger cutter. Auger drill comprises removable cutting part and auger member communicating with collapsible box-shaped sleeve in upper auger member part through outlet orifice. Movable unit has platform fixedly secured to drilling shaft and comprising steel body and steep plates. Installed on the platform are driving mechanism for threaded drill and platform and driving mechanism for auger drill. Both driving mechanisms include electric drive and gear wheels. During hole drilling threaded and auger drills are installed to rotate in mutually perpendicular directions so that auger drill may perform not less than 20 revolutions as threaded drill turns through 360°. Threaded drill rotation is accompanied with longitudinal movement thereof for distance equal to thread pitch c=1.414d, where d is outer diameter of threaded drill tube. During threaded drill rotation through 360° the greater cutter tip describes a circle having diameter D=2.414d and equal to hole diameter.

EFFECT: possibility to drill screw-like hole with coarse thread in one pass or in one working cycle.

4 cl, 23 dwg

FIELD: pile forming machines provided with auger drilling tools.

SUBSTANCE: machine has vertical post, head providing rotary movement, which is movable relative the post, as well as auger drill. Auger drill includes hollow core and at least one screw blade. Machine has extension tube with lower end fixedly secured to upper auger drill end. The head cooperates with extension tube. Machine also includes tubular piston sliding inside hollow core of auger drill and inside extension tube. Upper tubular piston end is connected to concrete supply pipeline. Machine comprises annular lifting means having the first end rigidly secured to upper end of extension tube and the second end rigidly secured to upper end of tubular piston.

EFFECT: increased depth and quality thereof.

6 cl, 5 dwg

FIELD: building, particularly for building load-bearing foundations and securing different mechanisms and devices in ground, including permafrost ones, for driving metal tubular piles, preferably having diameters of 168 - 219 mm.

SUBSTANCE: method involves pressing pile in ground along with simultaneous driving thereof with the use of inner inventory key. Torque is initially applied to screw blade by inventory key and then as pile driving resistance increases pile shaft is also involved in torque transfer process, wherein exceeding of predetermined torque value to inventory key or pile shaft is not allowed. Screw pile comprises cylindrical tubular shaft with guiding cone, screw blade and seat formed in lower shaft part for inner inventory key installation. Shaft is formed of metal and has means for taking torque transferred from above key.

EFFECT: reduced material consumption due to providing two-stage torque transfer scheme, increased reliability of pile driving process and pile as a whole.

7 cl, 8 dwg

FIELD: construction.

SUBSTANCE: device for erection of bored screw piles consists of a body, the upper part of which is made in the form of a hollow polyhedral nipple with a hole for a lock finger, and a rock cutting tool with a skirt. The middle and the lower parts of the body are made in the form of solid cylinders with a cross section of various diameter, besides, the middle part has larger diameter, and the lower part is of smaller diameter. In the middle cylindrical part there is a system of holes, a cavity to inject a concrete mix and a transverse slot, in which on a vertical axis placed in the vertical hole of the body, there is a slot-forming knife mounted with the possibility of rotation, the rear and front faces of the working part of which are formed by crossing of two cylindrical surfaces of various radius, axes of which are parallel to the axis of the device and lie in a single plane, and the axis of the cylindrical surface forming a rear face of the slot-forming knife matches the device axis, at the same time the lower and the upper ends are made with radial flat faces. The slot-forming knife is installed with the possibility to interact with a spring-loaded pusher to extend the slot-forming knife into a working position, and in the lower cylindrical part of the body there is a through longitudinal slot with a limiter arranged in it.

EFFECT: increased efficiency in erection of bored screw piles and their bearing capacity and stable and medium-stable soils, reduced material intensity of boring works.

7 cl, 5 dwg

Screw pile // 2435905

FIELD: construction.

SUBSTANCE: screw hollow shaft is made along the perimeter in the form of a multiple helical surface with screw grooves inside and outside of the screw hollow shaft at the angle of 30°-55° to its axis of rotation in the form of pockets of curvilinear shape with centres of curvature of curvilinear pockets on the helical surface arranged in turns outside and inside the cross section of the screw hollow shaft, is mounted from one strip of identical width, coiled into cylindrical turns, connected to each other along longitudinal edges, and the strip is bent in a wave-like manner along bending lines arranged at the angle to its longitudinal edges, to form helical surfaces along outer and inner surfaces directed to one and the same side at the angle of 30°-55° to the axis of rotation of the screw hollow shaft, as pockets of curvilinear shape along outer and inner surfaces, which along the perimetre of the screw hollow shaft may be different not only in shape, but also in dimensions, at the same time the distance between bending lines is equal to the sum of length of perimetres of geometric figures of pockets of inner and outer surfaces.

EFFECT: expansion of functional capabilities.

1 cl, 6 dwg

FIELD: construction.

SUBSTANCE: device to form bore piles comprises a working element to create a well for a pile in the form of a hub with a cone tip, equipped with a helical blade, in the end of which on the hub there is a cone segment fixed at the angle of helical blade lift with its top towards it, and rigidly fixed by means of a tubular shaft with exhaust holes with an anchor, a helical blade of which has the same winding and pitch as the helical blade of the hub, the working element drive in the form of a hollow rotary stem, where there is a sleeve installed movably with a vibrator fixed on it, at the same time the lower end of the stem is connected with the tubular shaft of the working element, and the upper end of the stem, while the working element is being screwed, is connected to a source of gas-dynamic pulse, and after screwing - with the pump to supply soil-reinforcing mixture or concrete.

EFFECT: increased bearing capacity of bore piles.

1 cl, 3 dwg

Screw pile // 2416695

FIELD: construction.

SUBSTANCE: screw pile comprises a shaft with a screw block in the form of a hub with a cone tip equipped with a helical blade, and the block is fixed at the front end in direction of screwing. At the same time a semi-cylindrical section, which is joined to the helical blade of the block by means of the cone sector, is fixed to the pile shaft along the helical line with the same pitch and direction as the block blade.

EFFECT: simplification of design.

1 cl, 1 dwg

Screw pile // 2413818

FIELD: construction.

SUBSTANCE: screw pile comprises shaft with screw block in the form of hub with cone tip equipped with helical blade, and the block is fixed at the front end in direction of screwing. Injector in the form of pipe with holes aligned perpendicularly to its axis is rigidly fixed to cone tip of block, and front end of pipe has a plug in the form of cone, and back one, arranged in block, is connected to pipe installed inside shaft, upper end of which is connected to pump to supply soil reinforcement mixture.

EFFECT: improved bearing capacity of screw pile in loose and compressible soils.

Screw pile // 2412307

FIELD: construction.

SUBSTANCE: shaft fixed on surface of soil with nut is mounted from sections arranged of eight, ten, twelve, etc. of even number of equilateral triangles connected to each other by means of two lateral sides, at the same time sections are connected to each other by free third sides of triangles to form hollow helical shaft, along perimetre of which there are opposite four, five, six and more broken right and left helical lines to form inner four, five, six and more helical grooves, directed towards each other with identical pitch.

EFFECT: expansion of technological resources, increased rigidity and vibration stability in screw pile, including helical hollow shaft with cutting edges.

1 cl, 7 dwg

FIELD: construction.

SUBSTANCE: device for erection of drilled pile consists of metal frame, roller with cone rolls, hollow drill column with tip, roller is rigidly connected to metal frame. Upper part of roller is shaped as truncated cone, generatrix of which is arranged in the form of second order curve. Tip is rigidly connected to hollow drill column and is arranged on its lower end. Reinforced bars of metal frame are rigidly connected to mount rings.

EFFECT: invention provides for the possibility to erect drilled pipe, also with application of small drilling equipment in constrained conditions.

4 cl, 3 dwg

FIELD: construction.

SUBSTANCE: method for making well for rolled-screw pile including drilling of conventionally cylindrical well. Roller unit and step accessory are connected to auger, device rotation is actuated for thread rolling, roller unit is brought into well, and thread making is started with the help of three rollers with various diametres and thicknesses in the form of truncated cone each, which are serially rolled one after another, and soil is impressed into well wall with angle of thread inclination between plane, where large wheel of each roller is located, and axis of roller unit rotation, making 76 degrees. Master roller executes primary rolling of thread, then intermediate roller of larger diametre and thickness expands groove, increasing thread dimension, and shaping roller of larger size completes soil compaction into well wall and thread rolling. Pitch, which provides for step accessory on auger per single complete rotation of shaping roller equal to 360 degrees makes 0.67 d, where d is diametre of roller unit pipe, and thread pitch corresponds to pitch of single turn of auger blade. Step accessory operates only in process of thread rolling together with rolling unit, and thus thread is rolled for the whole depth of well, reverse rotation is started, and roller unit is brought upwards along shaped thread, afterwards well is inspected and concreted. Device for method realisation comprises auger for drilling of conventionally cylindrical well, device for thread rolling made of roller unit, auger and step accessory. Roller unit includes steel pipe with diametre d with slots for rollers, steel bushings for axles of rollers, master roller with diametre of 0.52 d, intermediate roller with diametre of 0.71 d, shaping roller with diametre of 0.83 d, cover with tail, bottom. All three rollers are arranged as steel and are shaped as truncated cone, and straight line that coincides with diametre line of large wheel in each roller, crossing axis of roller unit rotation, is perpendicular to generatrix of pipe cylindrical surface in point of their crossing, and plane of each roller fit, i.e. plane of roller unit rotation axis crossing with point of crossing of roller rotation axis and large wheel of roller are at the angle of 120 degrees to similar plane of fit of each of two rollers.

EFFECT: simpler, affordable and cheaper arrangement of well for rolled-screw pile of high bearing capacity with the help of facilities for well drilling.

7 cl, 5 dwg

FIELD: construction.

SUBSTANCE: working member for device of screw bored piles consists of casing pipe, shoe with screw blade and a tip and is sunken in the soil by being screwed by applied torque moment and axial vertical force. Working member differs by the fact that a cone-shaped tip has sharpness angle of 90°, inclination angle of screw line of the blade is chosen as per the given formulas for ensuring rational values of force impacts from the submerging mechanism, there is tight demountable joint of casing pipes, shoe has the radius which is more than that of casing pipe, which is chosen from the given equation, owing to which soil pressure is relieved to casing pipe due to recovery of elastic soil deformation after introduction of the shoe. When the working member is submerged, the soil is expanded with a shoe to sides, thus being compacted. When design reference mark is reached, reinforcement cage is installed in casing pipe, and pile is concreted with simultaneous removal of the working member by unscrewing and rotating it in opposite direction; at that, the tip remains in the soil. By means of the above, soil is compacted once again, and cavities left with the shoe are filled with concrete.

EFFECT: considerable decrease of power consumption required for well erection process.

1 cl, 3 dwg

Screw pile // 2379421

FIELD: construction engineering.

SUBSTANCE: hollow screw body is made of one circular-coiled strip with its turns being interconnected in the tips. The strip is bent along bend lines inclined to its edges to form along the external and internal surfaces the one-way curved pocket-shaped spirals and helixes which can differ both in shape and dimensions on the perimetre of the screw pile. And the bend line distance is equal to the total length of perimetres of pocket geometries within the internal and external surfaces.

EFFECT: technological enhancement.

6 dwg

FIELD: building, particularly for building load-bearing foundations and securing different mechanisms and devices in ground, including permafrost ones, for driving metal tubular piles, preferably having diameters of 168 - 219 mm.

SUBSTANCE: method involves pressing pile in ground along with simultaneous driving thereof with the use of inner inventory key. Torque is initially applied to screw blade by inventory key and then as pile driving resistance increases pile shaft is also involved in torque transfer process, wherein exceeding of predetermined torque value to inventory key or pile shaft is not allowed. Screw pile comprises cylindrical tubular shaft with guiding cone, screw blade and seat formed in lower shaft part for inner inventory key installation. Shaft is formed of metal and has means for taking torque transferred from above key.

EFFECT: reduced material consumption due to providing two-stage torque transfer scheme, increased reliability of pile driving process and pile as a whole.

7 cl, 8 dwg

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