Method for cast-in-place pile forming

FIELD: building, particularly foundation building, namely for erecting pile foundations in seasonally freezing ground.

SUBSTANCE: method involves forming well extending for the full thickness of seasonally freezing ground layer, wherein well diameter increases pile diameter; installing heater in the well; transferring heat; driving casing pipe with detachable tip in ground through heater cavity; concreting well bore along with simultaneous lifting casing pipe and removing heater. Heat is supplied to concrete mixture within the limits of seasonally freezing ground after casing pipe removal. Inductor made as copper wire coil covered with heat-protective layer and located outside metal pipe is used as the heater. Heating is performed within 10-12 hours along with maintaining 75-80°C temperature of concrete mix by regulating inductor power up to obtaining concrete strength equal to 80% of design strength. After inductor removal from the well gap formed between well wall and pile body is filled with non-heaving ground.

EFFECT: reduced power inputs along with maintaining high productivity and increased load-bearing pile capacity.

2 cl, 3 dwg

 

The invention relates to the field of construction, in particular to the Foundation, and can be used during the construction of pile foundations in seasonally frozen soils.

When the installation of pile foundations in frozen soils or seasonally frozen (in winter) there is a problem, which consists in the slow hardening of concrete in contact with frozen ground. This factor causes a decrease in the bearing capacity of the pile. To solve this problem, heat unloading space throughout the depth of the frozen ground.

A known method of manufacturing bored piles in frozen ground, including the formation of wells, installation of frame and laying of the concrete mixture, with subsequent heating by heat in the surrounding pile the soil, and simultaneously provide heat supply of pumping ground water from the surrounding borehole soil. (A.S. USSR №688555, etc. 03.05.78, publ. 30.09.79).

The closest in technical essence and the achieved result is a method of manufacturing a printed piles on the author's certificate of the USSR No. 966155 from 14.01.81. According to this method, the well is formed to a depth of seasonal freezing diameter greater than the diameter of the pile shaft. Set it connected to the heat source of the annular tubular heater with insulated inner surface is completely, the external diameter of which is equal to the diameter of the hole, and exceeds the internal diameter of the pile shaft and served warm in the surrounding soil. At the same time through the cavity of the heater in the ground bury the casing with a lost tip. Concreting of the barrel is produced in two stages: the first stage concreted bottom of the barrel to the level of seasonal soil freezing with simultaneous lifting of the casing, then stop applying heat and remove the heater, and then concreted the remainder of the hole with simultaneous extraction of the casing.

The use of this method allows to reduce the duration of the production piles by integrating in time the process of concreting piles using casing with the process of heating a concrete mixture by heat in the surrounding pile the soil. However, the heat in the surrounding pile the soil affects the energy consumption of the process - to ensure proper hardening process and especially for its acceleration is required to increase the time for its heating, which leads to higher energy process. The lack of control over the process of hardening of the concrete mix can lead to overdrying of the concrete, and hence a decrease in its strength.

The objective of the proposed method is to reduce energy consumption while maintaining performance povyshenie bearing capacity of the pile.

The problem is solved in that in the known method devices bored piles, including education on the depth of seasonal freezing boreholes with a diameter greater than the diameter of the pile shaft, the installation into the borehole heater, the heat, the depth through the cavity of the heater in the soil casing with a lost tip, concreting of the wellbore with simultaneous lifting of the casing and removing the heater, the heat is served in the concrete mix within the depth of seasonal freezing of soil after extraction from the well casing, the heater is a coil made in the form of covered outside in heat-insulating layer of the coil of copper wire, placed outside the metal pipe, the heat lead within 10-12 hours, maintaining the temperature of the concrete mix 75-80°by regulating the power in the inductor, to set the strength of the concrete mixtures up to 80% of the project, then the inductor is removed from the wells, and in formed after removal of the inducer, the gap between the borehole wall and the pile shaft is placed napucenosti the ground. In addition, the problem is solved also by the fact that between the heater and the casing pipe install pipe made of asbestos cement, whose length corresponds to the depth of the bore of larger diameter, and the pipe is left in the body piles after extraction is possible heater.

The claimed invention differs from the prototype in that:

- heat is served in the concrete mix within the depth of seasonal freezing of soil after extraction from the well casing;

the heater serves as the inductor, made in the form of covered outside in heat-insulating layer of the coil of copper wire, placed outside the metal pipe;

- the heat are in for 10-12 hours, maintaining the temperature of the concrete mix 75-80°by regulating the power in the inductor, to set the strength of the concrete mixtures up to 80% of the project;

- formed after removal of the inducer, the gap between the borehole wall and the pile shaft is placed napucenosti the ground;

- between the heater and the casing pipe install pipe made of asbestos cement, whose length corresponds to the depth of the bore of larger diameter, while the pipe is left in the body piles after removing the heater from the well.

The temperature rise of the concrete mix up to 75-80°and maintaining it for 10-12 hours accelerates the hardening of the concrete mix. During this time provided a set of strength in concrete mixtures up to 80% of the project. The use of the heater coil, made in the form of covered outside in heat-insulating layer of the coil of copper wire, placed outside the metal pipe, the call is authorized to be not only effective directional heating of the concrete mixture, but to regulate and control the heating process while maintaining the necessary modes of heating (temperature and time).

Further, the method is illustrated by a specific example. In Fig. 1 shows a heater (coil)mounted in the hole formed in the frozen section of the soil; figure 2 - the intermediate stage of the manufacture of the pile of Fig. 3 - pile, obtained by the proposed method (longitudinal section).

The method is implemented as follows. In seasonally frozen ground 1 on the depth of seasonal freezing 17 one of the known methods, for example by drilling, to form the borehole 2, the diameter of which is greater than the diameter of the pile shaft 3. In a well set the inductor 4, which includes the coil 5 of the copper wire, placed on the outside of the metal pipe 6. The outer surface of the pipe 6 has a thin layer of insulating material 7. Outside the coil 5 is covered with a heat-insulating layer 8. The power regulation of the inductor 4 is the power supply 9, which is a frequency Converter, for example, power 30 kVA, and the working frequency of the output current of 8.0 kHz. The frequency Converter provides such regimes inductor, which allow for the heating of the concrete mixture within the depth of seasonal freezing of soil to a predetermined temperature (75-80° (C) for the time not me is it 2 hours to stabilize the desired temperature of the concrete mixture with an accuracy of up to ±5°within a specified period of time (10-12 hours), which is necessary for curing up to 80% of the project, automatically shut down the heating mode and stabilization after stabilisation time. Temperature control of concrete mixtures is performed automatically. Through the internal cavity of the inductor 4 in the underlying thawed soil 10 bury the casing 11 with a lost tip 12. Between the inductor and the casing pipe installed asbestos cement pipe 13. The length of the inductor 4 corresponds to the depth of the borehole 2. After immersion of the casing pipe in her lower reinforcing frame 14 and produce a concrete mixture with 15 simultaneous lifting of the casing 11 up to its extraction from the ground, after which include a power source 9. After the power source is shut off, and the inductor is removed from the well. When this asbestos-cement pipe inner surface forgives" in the concrete and the external surface, the remaining "dry", does not interfere with removal of the inductor 4 from the well. In formed after removing the inductor gap stack napucenosti the ground 16, such as a gravel-sand mixture.

This pile with guaranteed load capacity can be produced in a short time with ekonomie the energy consumption through the use of directional induction heating of the concrete mixture.

1. The way devices bored piles, including education on the depth of seasonal freezing boreholes with a diameter greater than the diameter of the pile shaft, the installation into the borehole heater, the heat, the depth through the cavity of the heater in the soil casing with a lost tip, concreting of the wellbore with simultaneous lifting of the casing and removing the heater, wherein the heat is served in the concrete mix within the depth of seasonal freezing of soil after extraction from the well casing, the heater is a coil made in the form of covered outside in heat-insulating layer of the coil of copper wire, placed outside the metal pipe, the heat are in for 10-12 h maintaining the temperature of the concrete mix 75-80°by regulating the power in the inductor, to set the strength of the concrete mixtures up to 80% of the project, then the inductor is removed from the wells, and in formed after removal of the inducer, the gap between the borehole wall and the pile shaft is placed napucenosti the ground.

2. The way devices bored piles according to claim 1, characterized in that between the heater and the casing pipe installed asbestos cement pipe length corresponding to the depth of the bore of larger diameter, which leave the body of the pile after removing agrevate who I am.



 

Same patents:

FIELD: building, particularly for erecting support structures, namely pile foundations, injection anchors, walls in ground, cast-in-place reinforced earth constructions and other geotechnic structures used for new building erection or reconstruction of existent buildings.

SUBSTANCE: method involves forming well or trench section in ground; at least partly filling thereof with hardening material or drilling agent, for instance with cement-bentonite one; substituting thereof with hardening material; immersing reinforcing cage with outer flexible shell connected to at least part of cage length in well. The flexible shell is permeable for liquid fraction of the hardening material and provides waterproofing of the cage after setting of above material and hardening material located outside the shell. Shell parameters are determined from the given correlations.

EFFECT: increased load-bearing capacity, reliability and service life, extended field of application.

24 cl, 9 dwg

FIELD: building, particularly cast-in-place building units, namely support structures.

SUBSTANCE: reinforced concrete column is formed in retained formwork and consists of upper support part and lower foundation part. Column includes reinforcement frame grouted with concrete mix and embedded members arranged in upper column part. Upper part of frame is located in retained formwork. Embedded members are in level with foundation slab marks and with flooring panel marks. Embedded members are formed as closed contours with stiffening ribs. Column is built in single- or multi-slot hollow. Projection of geometric retained formwork cross-section center coincides with that of lower reinforcement frame part. Arms of lower reinforcement form part extending in Y-axis direction are sized in accordance with given mathematical relation. Method of column erection involves forming single- or multi-slot hollow; producing reinforcement form with embedded members; forming retained formwork; installing above components; vertically placing the reinforcement frame in hollow so that frame is spaced a distance from hollow bottom; vertically adjusting and fixing upper column part to prevent transversal displacement thereof; grouting lower column part in bottom-top direction; grouting inner retained formwork area of upper column part. Hollow has dimensions measured in Y-axis direction determined from given relation.

EFFECT: possibility of simultaneous building erection in upward and downward directions relative ground level.

7 cl, 13 dwg

FIELD: building and construction.

SUBSTANCE: method includes serial vibration immersion of inventory elements into soil, which are mated between each other, and their following vibration extraction with concurrent filling of hollow in soil with concrete mixture. Inventory elements are used, which are made in form of profiled posts, having gates in lower portion, closed during immersion in soil and opened by flexible links during extraction of elements from soil and feeding of concrete mixture. At the same time profiled elements of longitudinal walling have lesser length, than length of profiled elements of vertical posts, which during immersion are pressed in for greater depth than profiled elements of longitudinal walling. First, profiled element of longitudinal walling is immersed, and then via guiding conductor profiled element of vertical post is densely mated to it and is than immersed. Concrete mixture is loaded in profiled element of longitudinal walling with its extraction with open gates and extracted element is immersed in next position adjacently to previous profiled element of vertical post being in soil. Concrete mixture is loaded into profiled element of vertical post during its extraction with open gates and extracted element if immersed into following position with concurrent mating to previous profiled element of longitudinal walling with use of guiding conductor. Then inventory elements are immersed again. Device for construction of bearing-limiting structures in soil includes crane or pile driver with vertical guide, vibration immersion driver and at least two inventory hollow elements. Inventory elements are made in form of profiled elements of longitudinal walling and profiled elements of vertical posts. Profiled elements of longitudinal walling have length less than length of profiled elements of vertical posts, which are made of hollow rectangular profiles, rigidly interconnected by solid rib along transverse axis along whole height of element, while vertical guide in lower portion is provided with guiding conductor.

EFFECT: higher efficiency, broader functional capabilities.

2 cl, 13 dwg

FIELD: building structures, particularly shallow foundations.

SUBSTANCE: method involves creating well by ground excavation, introducing preparatory portion of hardening material in well hollow including calculated part of hardening material; arranging explosive charge in lower well part; securing explosive charge; blowing explosive charge up to create cavity for widened foundation post part; crushing and widening above calculated part after explosion; introducing additional portion of hardening concrete in well up to 4/5 of well height; filling it with calculated part of above material portion. Concrete for casting is used as preparatory hardening material.

EFFECT: reduced time, increased simplicity of foundation building and reliability.

2 cl, 5 dwg

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Pile // 2186905
The invention relates to the construction and can be used during the execution of pile foundations of buildings and structures

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SUBSTANCE: device comprises percussion unit with working forming unit made as sharpened cylinder and integrated in front part of percussion unit. Sharpened cylinder has outline including alternating convex and concave parts. Operational forming unit comprises two members with conical surfaces on front outer side thereof and spaced one from another along longitudinal device axis. Operational forming unit has seat surfaces located on outer rear part surface of front member and on inner surface of rear member.

EFFECT: increased efficiency of well driving.

3 cl, 3 dwg

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FIELD: building machinery, particularly for forming cast-in-place piles, pile foundations, retaining walls, slope protection structures and ground bases for floors.

SUBSTANCE: device comprises percussion unit with working forming unit made as sharpened cylinder and integrated in front part of percussion unit. Sharpened cylinder has outline including alternating convex and concave parts. Operational forming unit comprises two members with conical surfaces on front outer side thereof and spaced one from another along longitudinal device axis. Operational forming unit has seat surfaces located on outer rear part surface of front member and on inner surface of rear member.

EFFECT: increased efficiency of well driving.

3 cl, 3 dwg

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