CN110644478A

CN110644478A - Construction method of non-dumping pile foundation suitable for silt gelation

Info

Publication number: CN110644478A
Application number: CN201810666828.9A
Authority: CN
Inventors: 宋奇镛
Original assignee: Ext Corp
Current assignee: Ext Corp
Priority date: 2018-06-26
Filing date: 2018-06-26
Publication date: 2020-01-03

Abstract

The present invention relates to a method for constructing a non-earth-removing pile foundation, which is capable of minimizing the influence on the surrounding ground and significantly shortening the construction period of the pile foundation by injecting a pile body into gelled sediment, which is formed by stirring the sediment softened by the rotational injection of a stirring device and a gelling agent, and setting the gelled sediment on a supporting foundation, thereby enabling the pile body to be embedded into the foundation while minimizing the influence on the surrounding ground without digging. The invention discloses a construction method of a non-dumping pile foundation suitable for silt gelation, which comprises the following steps: (a) measuring the position of a pile body to be constructed; (b) rotating a stirring device to a pile construction site until the foundation is supported to soften the silt in the foundation, spraying a gelling agent to the stirring device, and stirring the softened silt and the gelling agent to gelatinize (gel) the silt; (c) removing the stirring device, and penetrating the pile body into the gelled sediment by means of dead weight so as to enable the pile body to be arranged on the supporting foundation; and (d) curing the gelled sediment and fixing the pile body.

Description

Construction method of non-dumping pile foundation suitable for silt gelation

Technical Field

The present invention relates to a method for constructing a non-earth-removing pile foundation, which is capable of minimizing the influence on the surrounding ground and significantly shortening the construction period of the pile foundation by injecting a pile body into gelled sediment, which is formed by stirring the sediment softened by the rotational injection of a stirring device and a gelling agent, and setting the gelled sediment on a supporting foundation, thereby enabling the pile body to be embedded into the foundation while minimizing the influence on the surrounding ground without digging.

Background

The method of constructing a pile foundation is roughly classified into a method of constructing a pile foundation by hammering a pile into a soil layer and a method of inserting a pile body into a soil layer after punching a hole in the soil layer.

Although the pile foundation construction of the pile driving method is quick and simple in construction time, much noise and vibration occur, and a penetration range has a limit. In addition, pile foundation construction to which the embedding method is applied is increasing in various civil engineering construction sites with the enhancement of regulations regarding noise and vibration.

The embedded pile is to excavate a foundation 1 using an excavating apparatus 4 to form a through hole 11 in a soil layer (fig. 1 (a)). When the perforations 11 are formed, the excavated sediment 13 is discharged to the outside.

After the filling material 2 is poured into the through-hole 11 (fig. 1 (b)), the pile body 3 is inserted into the through-hole 11 (fig. 1 (c)), and the filling material 2 is poured into the remaining space, thereby completing the piling work (fig. 1 (d)).

In addition, various coastal works such as national industrial bases and aviation are constructed every year. When large-scale construction is performed on soft ground around a filling ground or a coast, a large amount of sandy soil is generated on site in the process of drilling the ground to embed a pile when foundation construction is performed in the above-mentioned region. However, since the above-mentioned site excavated earth such as a puddle or slurry of the landfill needs to be disposed of as waste or reused after a certain process unlike general silt, the above-mentioned silt causes 2 times of pollution and causes a serious burden on the disposal space and disposal cost.

That is, since excavation of sediment inevitably occurs in the construction of the embedded pile foundation, construction costs for transporting waste sediment occur. And, the cost of injecting cement slurry between the pile body and the bore hole is increased.

And moreover, silt is removed during perforation, so that the perforated hole wall is exposed, the silt around the hole wall is softened, and the problem of reduction of friction force is caused. Further, the formation of the perforations causes problems such as the movement of the groundwater level and the sinking of the surrounding ground.

In addition, a PHC pile manufactured by applying a prestress to a pile body and then forming the pile body in a circular shape is generally used, and a sealing cap is coupled to an end portion of the PHC pile for fixing a PC steel wire, acting on a mold bottom when manufacturing the pile body, connecting the PHC piles adjacent to each other in the vertical direction, or the like. Further, a front end of a PHC pile provided at the lowermost part of the pile body is coupled to a front end of a nipple or a flat plate type ferrule, and an end cap is coupled to an upper end of a PHC pile provided at the uppermost part (see, for example, patent nos. 10 to 0995849).

Therefore, in the past, for the construction of one pile body, PHC piles of three specifications of the upper end pile, the middle pile and the lower end pile were manufactured, the number of required pile bodies was calculated according to the results of on-site ground investigation, and PHC piles of corresponding specifications were transported.

However, since the penetration depth of the pile changes depending on the ground state at the actual site and the experimental result, the remaining pile is secured in each specification in consideration of the possibility of the above-described fluctuation.

And, preferably, each specification of the pilings ensures a separate production line. However, the production amount of piles of each specification differs, and the demand is predicted to vary, and when a plurality of production lines are operated, the production efficiency is lowered. In addition, inventory is generated when supply and demand are unbalanced, and the PHC tubular piles are managed in accordance with each specification on site, so that the site management is complicated.

Disclosure of Invention

Technical problem to be solved by the invention

In order to solve the above problems, the present invention provides a method for constructing a non-discharging pile foundation to which gelation of silt is applied, which can minimize the influence on the surrounding ground by preventing the hole wall from being exposed without digging up earth when embedding a pile body.

The invention provides a non-dumping pile foundation construction method suitable for silt gelatinization, which can greatly shorten the construction period of a pile foundation.

The invention provides a construction method of a non-discharging pile foundation suitable for silt gelation, which is characterized in that when a PHC tubular pile is manufactured, unit piles of one specification are manufactured in a factory and assembled and used on site, thereby improving the effectiveness of pile body manufacturing and raw material supply and management and greatly improving the economy.

Technical scheme for solving problems

According to the invention of the preferred embodiment, in order to penetrate the pile body into the foundation, the method comprises the following steps: (a) measuring the position of a pile body to be constructed; (b) rotating a penetrating stirring device to a pile construction site until the foundation is supported to soften the silt in the foundation, spraying a gelling agent to the stirring device, and stirring the softened silt and the gelling agent to gelatinize (gel) the silt; (c) removing the stirring device, and penetrating the pile body into the gelled sediment by means of self weight to enable the pile body to be arranged on a supporting foundation; and (d) curing the gelled sediment and fixing the pile body.

According to another preferred embodiment of the present invention, in the step (b), a space for removing the upper sand from the ground to a predetermined depth is formed at the pile construction site.

According to another preferred embodiment of the present invention, the stirring device is provided with a soil discharge digging part having a continuous screw for soil discharge formed at a lower part thereof, and a stirring part having a stirring blade formed at an upper part thereof.

According to another preferred embodiment of the present invention, a reverse circulation portion is further formed between the excavation portion for discharging soil and the stirring portion of the stirring device, and the reverse circulation portion is formed with a non-reverse screw for discharging soil arranged in a direction opposite to the continuous screw for discharging soil.

According to the invention of another preferred embodiment, the stirring device comprises: a bolt sleeve for soil discharge, which has a continuous screw thread for soil discharge formed on the outer cylindrical surface and is used for digging and discharging the upper silt of the pile construction site to form a space part; and a non-discharging stirring rod, which is provided with a stirring wing on the outer cylindrical surface, is formed in the discharging bolt sleeve in a way of moving up and down and rotating, is used for softening the silt at the lower part of the space part, and is stirred with the gelatinizing agent.

According to another preferred embodiment of the present invention, a torque sensor for measuring a rotation torque of the stirring device is provided at an upper end of the stirring device, and the stirring work is repeatedly performed until a torque value measured by the torque sensor drops to or below a set target torque value in the step (b).

According to the invention of another preferred embodiment, a nozzle for injecting at least one of high-pressure air or high-pressure water is formed in the stirring device, and the silt is softened by the high-pressure injection through the nozzle.

According to the invention of another preferred embodiment, an expansion reinforcing plate with a larger diameter than the main body of the pile body is combined at the lower end of the pile body.

According to the invention of another preferred embodiment, in the step (c), the pile body is constructed by connecting a plurality of unit piles in a longitudinal direction.

According to the present invention of another preferred embodiment, the plurality of unit piles are coupled to each other by coupling members formed to protrude to the outside of the pile body.

According to the present invention of another preferred embodiment, in the step (c), a pile guide for guiding penetration of the unit pile is provided at an upper portion of the ground of the pile body construction site, and a fixing member for selectively hooking and supporting the protruding portion of the coupling member is formed at the pile guide.

According to the invention of another preferred embodiment, the unit pile includes: a hollow concrete pile body; a lower cover coupled to a lower end of the concrete pile body by a bolt; and an upper cover coupled to an upper end of the concrete pile body by a bolt.

According to another preferred embodiment of the present invention, the gelling agent comprises 35 to 60 wt% of an inorganic binder, 20 to 45 wt% of water, and 0.15 to 7 wt% of a dispersant.

According to another preferred embodiment of the invention, the gelling agent is added in an amount of 150 to 320 parts by weight relative to 100 parts by weight of the onsite silt.

According to another preferred embodiment of the invention, the weight of the inorganic binder relative to the weight of the total inorganic binder comprises SO₃7 to 15% by weight of Al₂O₃8 to 15 wt% and CaO45 to 55 wt%.

According to the invention of another preferred embodiment, the pile body is constructed by connecting a plurality of unit piles in a longitudinal direction, the unit piles including: a hollow concrete pile main body with the upper end and the lower end exposed is formed in the center; a plurality of PC nuts embedded in both ends of the concrete pile body, respectively; and a PC steel wire having both ends respectively coupled to the PC nuts and fixed thereto.

According to the present invention of another preferred embodiment, adjacent unit piles are connected to each other by bolting the coupling members to the PC nuts.

According to the present invention of another preferred embodiment, a front ferrule or an expansion type reinforcing plate is bolt-combined with a PC nut at the lower end of the unit pile located at the lowermost portion.

According to the present invention of another preferred embodiment, an end cap is bolt-combined with a PC nut at the upper end of the unit pile located at the uppermost portion.

According to another preferred embodiment of the present invention, enlarged portions having enlarged diameters are formed at both ends of the PC steel wire, at least one or more PC nuts at both ends are formed in a cylindrical shape by closely attaching a pair of right and left semi-cylindrical 1 st fixing members and a pair of right and left semi-cylindrical 2 nd fixing members to each other, and the PC steel wire is passed through a wire fixing tube of a hook plate for hooking the enlarged portions and a cylindrical coupling tube coupled to the outside of the wire fixing tube are formed at one end of the 1 st fixing member and the 2 nd fixing member.

According to another preferred embodiment of the present invention, the coupling pipe is formed to be longer than the wire fixing pipe, and is formed to extend a predetermined length to the other end side of the wire fixing pipe, and the wire fixing pipe and the coupling pipe are coupled to each other by a screw.

According to the present invention in another preferred embodiment, a fixing flange protruding to the outside of the coupling pipe is formed at the outside of one end or the other end of the wire fixing pipe.

According to another preferred embodiment of the present invention, a fixing flange embedded into the concrete pile body is formed on the outer side of the coupling pipe.

ADVANTAGEOUS EFFECTS OF INVENTION

The invention has the following effects:

first, when the pile body is embedded, the silt softened by the rotational penetration of the stirring device and the gelling agent are stirred and gelled, and the mixture is penetrated into the pile body by its own weight, and is set on the supporting base. Therefore, excavation of earth does not occur, and environmental pollution due to excavation of earth is avoided. Further, the work and time for processing the excavated soil can be saved, the workability and the economical efficiency can be improved, and the construction period can be shortened.

Second, since the properties of the ground of the embedded pile are temporarily changed and the pile is embedded, it is possible to prevent the problem of the hole wall being exposed or the problem of the sand being softened, which has been conventionally caused by the formation of the through hole, and to minimize the influence on the surrounding ground.

Thirdly, since the pile driving construction is performed in two steps of the ground surface gelation and the pile body penetration, the conventional step of treating cement paste between the pile body and the drilled hole can be omitted, and the pile foundation construction period can be shortened.

Fourthly, when a space is formed at a predetermined depth from the ground at a pile foundation construction site, gelled sand and sand are prevented from overflowing from the ground due to the volume of the pile body, and a surplus space is secured.

Fifth, the unit piles are configured by the cement pile main body to which the separate caps or covers are not attached at both ends, so that the unit pile specifications for manufacturing the PHC pile and the like can be unified. Therefore, after the unit pile is transported to the site, a coupling member is screwed to the PC nut embedded in the end portion as necessary, and is used as an intermediate pile. A tip ferrule, an expanding reinforcing plate, or an end cap is screwed to the PC nut formed at the end of the unit pile, and is used as a lower pile or an upper pile. Therefore, only one specification of unit piles needs to be produced in a factory, the manufacturing efficiency is high, the raw material supply efficiency is high, and the economical efficiency is high.

Drawings

FIG. 1 is a drawing showing a conventional pile foundation construction method;

FIG. 2 is a drawing showing processes of respective steps of a non-discharging pile foundation construction method by silt gelation according to the present invention;

FIG. 3 is a schematic view showing steps (b) and (c) of a method for constructing a non-discharging pile foundation by gelatinizing silt according to the present invention, in which a space is formed;

FIG. 4 is a perspective view showing a stirring device according to an embodiment;

FIG. 5 is a drawing showing a construction method using the stirring apparatus shown in FIG. 4;

FIG. 6 is a perspective view of a stirring device having a reverse circulation part formed therein;

FIG. 7 is a drawing showing a construction method using a stirring apparatus of another embodiment;

FIG. 8 is a perspective view of a stirring device formed with a nozzle;

fig. 9 is a drawing showing a state where a pile body of an embodiment is penetrated into the ground;

fig. 10 is a drawing illustrating a construction process of a unit pile using a pile guide;

fig. 11 is a perspective view showing an embodiment of a unit pile;

fig. 12 is a sectional view showing a unit pile;

fig. 13 is a perspective view showing a coupling relationship of unit piles by means of coupling members;

fig. 14 is a sectional perspective view showing a unit pile combined with a nose ferrule;

fig. 15 is a sectional perspective view showing a unit pile incorporating an end cap;

FIG. 16 is a perspective view illustrating a coupling relationship of a PC nut and a PC steel wire according to an embodiment;

fig. 17 is a sectional view showing a state in which the PC nut and the PC wire shown in fig. 16 are coupled;

FIG. 18 is a sectional view showing a state where a PC nut having a hook portion is coupled to a PC wire;

FIG. 19 is a perspective view showing a state where a PC nut and a PC wire are coupled to each other according to another embodiment;

FIG. 20 is a sectional view showing a state where the PC nut and the PC wire are coupled to each other as shown in FIG. 19;

FIG. 21 is a sectional view showing a state in which a PC nut having a fixing flange formed on a wire fixing pipe is coupled to a PC wire;

fig. 22 is a sectional view showing a state in which a PC nut having a fixing flange formed on a coupling pipe is coupled to a PC wire.

Description of the reference numerals

1: ground 11: punch

12 space part 13 excavated sand

2 filling material 3 pile

3', 3' -unit pile 31-concrete pile body

32,32a lower cover 33,33a upper cover

34 combining part 341 upper plate

342 lower plate 343 support plate

35 expansion reinforcing plate 36 PC steel wire

361 enlarged part 37, front metal ferrule

38 end cap 39 reinforcing band

4: digging device 5: gelled silt

6 stirring device 61 soil discharge digging part

611 continuous screw thread for soil discharge 62 reverse circulation part

621 non-earth-removing reverse screw 63, stirring part

631 stirring wing 632 jet orifice

633: nozzle 64: bolt sleeve for soil discharge

641 continuous screw thread for discharging soil 65 non-discharging soil stirring rod

651 stirring wing 66 excavating bit

7 pile guide 71 fixing part

8: PC nut 81: steel wire fixing tube

81a 1 st fixing member 81b 2 nd fixing member

811 hanging plate 812 through hole

813 hanging part 814 fixed flange

82 connecting pipe 821 fixed flange

B is bolt

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments.

Fig. 2 is a drawing showing the steps of a method for constructing a non-discharging pile foundation by the gelation of silt according to the present invention.

As shown in fig. 2, the method for constructing a non-discharging pile foundation by the gelation of silt according to the present invention includes, in order to penetrate a pile body 3 into a foundation 1: (a) measuring the position of the pile body 3 to be constructed; (b) a step of rotationally injecting a stirring device 6 into a construction site of a pile body 3 until the foundation is supported to soften the silt in the foundation 1, spraying a gelling agent to the stirring device 6, and stirring the softened silt and the gelling agent to gelatinize the silt (gel); (c) removing the stirring device 6, and penetrating the pile body 3 into the gelled sediment 5 by self weight and placing the pile body on a supporting foundation; and (d) curing the gelled sediment 5 and fixing the pile body 3.

The construction method of a non-discharging pile foundation in which silt is gelled according to the present invention is to penetrate a pile body 3 into a foundation 1, starting from (a) a step of measuring a position where the pile body 3 is to be constructed.

Then, (b) rotating and penetrating a stirring device 6 into the supporting ground at the construction site of the pile body 3 to soften the sediment in the foundation 1, and spraying a gelling agent to the stirring device 6, so that the softened sediment is stirred with the gelling agent to gel the sediment (gel) (fig. 2 (a)).

That is, the stirring means 6 is rotatably penetrated and the gelling agent is sprayed in the (b) step.

The silt in the ground softened by the penetration of the rotation of the stirring device 6 is stirred with the gelling agent to form gelled silt 5.

The gelling agent is used to temporarily increase the viscosity and elasticity of the softened sediment to gel (gel), and after the pile body 3 is inserted into the gelled sediment 5 in step (c) described later, the gelled sediment 5 is solidified to support the pile body 3.

The stirring of the gelling agent and the silt is not intended to form solidified soil by mixing the gelling agent and the silt, but is intended to increase the stability (consistency) of the silt so that the silt temporarily exceeds the liquid limit (liquidlimit) and becomes a liquid state with high fluidity that easily penetrates pile body 3.

That is, the silt is once made liquid by stirring the gelling agent and the silt, and after a certain time, the silt is solidified to support the pile body 3.

In this case, the degree of gelation of the sand varies depending on the weight and diameter of pile 3. That is, if the pile 3 has a large self-weight or diameter, the sand is gelled so as to be able to penetrate into the pile 3 by the self-weight.

The present invention is more applicable to soft ground such as clay layer where the mud and sand are more easily gelated.

And (c) removing the stirring device 6, and inserting the pile body 3 into the gelled sediment 5 by its own weight to be placed on the supporting base ((b) of fig. 2), and (d) curing the gelled sediment 5 to fix the pile body 3 ((c) of fig. 2).

The pile body 3 can be a PHC pipe pile, a steel pipe pile, a concrete pile, an I-beam and the like.

In the step (c), the pile 3 can be placed on the supporting ground by applying pressure to the upper end of the pile 3 after the pile 3 is inserted by its own weight.

Since even if pile 3 is driven into foundation 1 by its own weight, there is a possibility that gelled soil 5 between the front end of pile 3 and the supporting foundation will not be able to be stably seated on the supporting foundation.

Therefore, the front end of pile body 3 is caused to run into lower gelled soil 5 by knocking or pressing the auger, so as to be seated on the supporting ground.

As described above, in the present invention, since the gelled sediment 5 directly penetrates the pile 3 by its own weight when the pile 3 is buried, excavation does not occur. Therefore, the excavated sediment is not discharged, and the problem of the exposed hole wall or the softened hole wall formed with the through hole is avoided, so that the cylindrical friction force is easily ensured, and the peripheral low water level is not changed.

Further, the construction time of the pile 3 can be significantly shortened by omitting the treatment of excavating sand or the grouting step between the perforated hole and the pile 3.

That is, conventionally, if the height of the filling material 2 to be grouted is high, it is difficult to insert the pile 3, and therefore, the pile 3 is driven to insert after 1 injection of the filling material 2. Further, after the pile body 3 is inserted, the filler 2 is poured again, which makes the construction troublesome.

However, in the present invention, the conventional processes of digging and removing sand and sand from the ground, grouting a filler, and penetrating a pile can be completed in 2 steps of gelling the ground and penetrating the pile. Therefore, the construction steps are shortened, and the construction time is also greatly shortened.

The gelling agent may include 35 to 60 wt% of an inorganic binder, 20 to 45 wt% of water, and 0.15 to 7 wt% of a dispersant.

The inorganic binder causes the gelled silt 5 to solidify again.

If the inorganic binder is less than 35% by weight, the strength of the gelled soil 5 is hard to develop after curing and solidification, and if it exceeds 60% by weight, the water content is reduced, which hinders the gelation of the soil.

The water is directly related to the stability of the silt.

If the water content is less than 20 wt%, the silt is not easily gelled, and if the water content is more than 45 wt%, the curing or solidification time is delayed or the strength of the solidified silt is reduced, and the cylindrical surface friction of the pile body 3 is reduced.

The dispersant serves to prevent the silt particles, which are pulverized by stirring, from being coagulated again.

The dispersant is required to be mixed in an amount of 0.15 wt% or more in order to function as a dispersant, and if it exceeds 7 wt%, it delays the solidification of the silt, resulting in a decrease in strength.

And, preferably, the gelling agent is charged in an amount of 150 to 320 parts by weight with respect to 100 parts by weight of the in-situ silt.

The amount of the gelling agent to be added is determined in accordance with the soil quality, the weight of the pile body 3, and the like, and the above numerical range is suitable in consideration of the gelation of the sand and the curing time.

If the gelling agent is less than 150 parts by weight, it is difficult to form a mud-sand gel, and if it is more than 320 parts by weight, the required amount consumes excessive curing time, and thus, it is not economical.

And the inorganic binder comprises SO relative to the weight of the entire inorganic binder₃7 to 15% by weight of Al₂O₃8 to 15 wt% and CaO45 to 55 wt%.

The SO₃By generating ettringite hydrate, the binding force with soil is improved, and the composition is compact.

If the SO is present₃When the amount is less than 7% by weight, the initial strength is low, and when the amount is more than 15% by weight, rapid transformation from ettringite hydrate to monosulfate hydrate occurs, and cracks may occur due to overexpansion.

The Al is₂O₃Has an effect on the strength.

If said Al is present₂O₃Less than 8 wt%, strength is difficult to develop due to the deficiency of alkali components, and if more than 15 wt%, the reaction is excessively rapid, resulting in a decrease in mobility.

And reacting CaO with water, and curing the gelled sediment 5 to strengthen the hardness of the sediment.

If the CaO content is less than 45% by weight, it is difficult to secure sufficient hardness, and if it exceeds 55% by weight, the pH value of the gelled sludge 5 is raised to a suitable level or higher after curing.

FIG. 3 is a drawing showing steps (b) and (c) of a method for constructing a non-discharging pile foundation to which gelation of silt is applied, in which a space is formed.

As shown in fig. 3, in the step (b), a space 12 for removing the sediment at the upper part is formed from the ground to a predetermined depth at the construction site of the pile body 3.

When the silt is softened by the stirring device 6, even if the softened silt is not removed, the gelled silt 5 overflows from the upper part of the ground due to the volume of the pile body 3 when the silt is injected into the pile body 3. Therefore, various complaints such as troublesome work for treating the effluent water, environmental pollution, etc. are caused.

Therefore, space 12 of a predetermined depth is formed at the construction site of pile 3 in advance, and the upper sand is removed to secure a predetermined excess space, so that gelled sand 5 can be prevented from overflowing the ground after penetrating pile 3.

Preferably, the volume of space 12 is greater than or equal to the sum of the volume of pile 3 penetrating foundation 1, the volume of gelling agent, and the volume of silt softened by silt.

In the formation of space 12, step (b) is a process (fig. 3 (c)) in which space 12 is formed by removing silt with a separate device, stirring device 6 is put into space 12 to soften the silt at the lower part of space 12 (fig. 3 (b)), gelling agent is sprayed to stirring device 6, and the softened silt and gelling agent are stirred to gel the silt.

Then, the gelled sediment 5 is inserted into pile body 3 by its own weight and set (fig. 3 (d)), and the gelled sediment 5 is cured to fix pile body 3.

A torque sensor for measuring a rotation torque of the stirring device 6 is formed at an upper end of the stirring device 6, and the stirring work is repeated until a torque value measured by the torque sensor drops to or below a set target torque value in the step (b).

The gelled sediment 5 has a difference in fluidity depending on the weight of the pile 3. That is, the smaller the weight of pile 3 is, the greater the fluidity is required.

The fluidity of the gelled silt 5 is affected by the stirring time or the stirring speed, and therefore, the stirring time can be adjusted according to the required fluidity.

That is, the longer the stirring time, the more the fluidity is increased, and therefore, the stirring is continued until the required fluidity is secured.

At this time, the fluidity of the gelled soil 5 can be tested alone. However, since this test requires a long time, the fluidity is checked from the rotational resistance, i.e., the torque value, of the stirring device 6.

Accordingly, the target torque value is set based on the weight of pile 3, and when the torque value measured by the torque sensor becomes equal to or less than the set target torque value during the stirring operation, it is confirmed that the required fluidity can be secured, and the stirring operation is stopped.

FIG. 4 is a perspective view showing a stirring device according to an embodiment; fig. 5 is a drawing showing a construction method using the stirring device shown in fig. 4.

As shown in fig. 4, the stirring device 6 is configured such that the excavating part 61 formed with the continuous screw 611 for discharging soil is disposed at the lower part, and the stirring part 63 formed with the stirring blade 631 is disposed at the upper part of the excavating part 61.

The stirring device 6 is formed into a cylindrical pipe and is composed of a soil discharge excavation portion 61 disposed at a lower portion of the cylindrical pipe and a stirring portion 63 disposed at an upper portion.

The soil discharge excavation unit 61 excavates the foundation 1 to discharge sand and sand to the outside.

An excavating bit 66 is coupled to a front end of the excavating part 61.

The soil discharge excavation unit 61 excavates the foundation 1 through the excavation bit 66 at the lower end and the soil discharge continuous screw 611 on the outer cylindrical surface, and discharges the excavated sediment above the ground through the soil discharge continuous screw 611, thereby forming a space 12 (fig. 5 (a)) from the ground to a predetermined depth.

Preferably, the length of the excavation portion 61 is shorter than the length of the space portion 12.

The soil discharge excavation unit 61 removes the upper silt to form the space 12, and then the stirring unit 63 at the upper portion of the stirring device 6 is inserted into the lower portion of the space 12, whereby the silt at the lower portion of the space 12 is stirred without soil discharge (fig. 5 (b)).

At this time, even if the soil discharging and excavating part 61 penetrates into the lower part of the space part 12 and the silt in the lower part moves upward, the stirring part 63 can prevent the silt from moving upward, and the space part 12 can be sufficiently secured.

As described above, when the stirring device 6 including the soil discharging excavation portion 61 and the stirring portion 63 is used, the operation of forming the space portion 12 can be performed without an additional excavation device, and the lower silt can be stirred while securing the space portion 12.

The gelling agent is supplied to the cylindrical tube of the stirring device 6.

The supplied gelling agent is jetted into the ground through a plurality of jet ports 632 that communicate with the cylindrical pipe.

The ejection port 632 is formed in plurality spaced apart from each other in the longitudinal direction of the cylindrical pipe. In order to uniformly spray the gelling agent, two or more spray ports 632 are formed in plan view.

Fig. 6 is a perspective view of the stirring device having the reverse circulation portion.

As shown in fig. 6, a reverse circulation unit 62 having a non-discharging reverse screw 621 disposed in the opposite direction to the discharging continuous screw 611 is formed between the discharging excavation unit 61 and the stirring unit 63 of the stirring device 6.

When the sediment at the front end is moved upward by the soil discharge and excavation portion 61, a hole is formed in the lower portion.

Therefore, the silt moving upward is moved downward again by the reverse circulation portion 62.

Thus, the silt and the gelling agent are stirred up and down by the soil discharge excavation section 61 and the reverse circulation section 62, and the occurrence of a hole at the tip of the stirring device 6 is prevented.

Preferably, the non-discharging reverse thread 621 is formed discontinuously, i.e., intermittently, a bolt, differently from the discharging continuous thread 611, to prevent upper movement of the silt from occurring due to the rotation of the stirring device 6.

FIG. 7 is a drawing showing a method of constructing a stirring apparatus according to another embodiment.

As shown in fig. 7, the stirring device 6 is used for excavating and discharging sediment in the upper portion of the construction site of the pile body 3 to form a space 12, and includes: a soil discharging bolt bushing 64 having a soil discharging continuous screw 641 formed on an outer cylindrical surface thereof, and a non-soil discharging stirring rod 65 which is vertically and rotatably installed inside the soil discharging bolt bushing 64, has a stirring blade 651 formed on an outer cylindrical surface thereof, and softens the sand and sand at the lower portion of the space 12 and stirs the softened sand and sand with the gelling agent.

The stirring device 6 may be composed of a soil discharging bolt bushing 64 and a non-soil discharging stirring rod 65, differently from the embodiment illustrated in fig. 4 to 6.

The bolt sleeve 64 for discharging soil and the non-discharging stirring rod 65 are simultaneously and rotatably inserted into the construction site of the pile body 3.

The discharging bolt sleeve 64 has a discharging continuous thread 641 on an outer cylindrical surface. The bolt sleeve 64 for discharging soil excavates the silt in the upper part of the foundation 1, and discharges soil to the outside through the continuous screw 641 for discharging soil, thereby forming a space 12 from the ground to a predetermined depth.

The soil discharge bolt sleeve 64 excavates the foundation 1 only to the depth of the space portion 12.

The non-discharging agitator 65 is movable up and down and rotatable inside the discharging bolt housing 64.

The non-discharging agitator 65 is rotated separately from the discharging bolt housing 64.

The non-discharging agitating bar 65 may be formed of a cylindrical pipe having agitating wings 651 formed on an outer cylindrical surface thereof and an excavating bit 66 coupled to a front end thereof.

The gelling agent is supplied to the cylindrical pipe of the non-discharging agitating bar 65.

The supplied gelling agent is jetted into the ground through a plurality of jet ports communicating with the cylindrical pipe.

The non-discharging stirring rod 65 excavates the foundation 1 by means of the lower end excavating bit 66, and rotates while descending, and the stirring wing 651 softens the sand at the construction site of the pile body 3. And, the gelling agent sprayed through the cylindrical pipe of the non-discharging stirring rod 65 is stirred with the silt, so that the silt is gelled.

Fig. 8 is a perspective view of a stirring device formed with a nozzle.

As shown in fig. 8, at least one or more nozzles 633 for jetting at least high pressure air or high pressure water are formed in the stirring device 6, so that the silt is softened by the high pressure jetting by means of the nozzles 633.

When the stirring device 6 is rotated, air or water is sprayed to the ground through the nozzle 633 at a high pressure, so that the mud and sand around the mud and sand are softened more easily in the step (b).

Thus, the penetration of the foundation 1 of the stirring device 6 or the stirring of the silt and the gelling agent can be performed more easily.

Fig. 9 is a drawing showing a state where the pile body of the embodiment is inserted into the ground.

As shown in fig. 9, an expansion reinforcing plate 35 having a larger diameter than the main body of the pile body 3 is coupled to the lower end of the pile body 3.

The expansion reinforcing plate 35 can be welded and fixed at the lower end of the pile body 3.

The expansion reinforcing plate 35 can increase the area of the front end of the pile body 3 and improve the front end supporting force.

And, in the step (c), the pile body 3 may be constructed by connecting a plurality of unit piles 3',3 ″ in a longitudinal direction.

If the depth of the supporting foundation is deeper, a plurality of unit piles 3', 3' are connected up and down to carry out pile foundation construction.

At this time, the plurality of unit piles 3',3 ″ are coupled to each other by means of the coupling member 34, and the coupling member 34 is formed to protrude to the outside of the pile body 3.

The coupling parts 34 are formed by welding reinforcing plates having an outer diameter larger than that of the unit piles 3',3 "between the adjacent unit piles 3', 3". Or a ring-shaped reinforcing band is combined on the steel plate combined along the outer cylindrical surface of the upper end of the concrete unit pile to form the combination part 34.

The coupling member 34 is formed to protrude from the side surface of the pile body 3, thereby improving pile support.

Fig. 10 is a drawing illustrating a construction process of a unit pile using a pile guide.

As shown in fig. 10, in the step (c), a pile guide 7 for guiding penetration of the unit piles 3',3 ″ is provided on an upper ground portion of the construction site of the pile body 3, and a fixing member 71 for selectively hooking and supporting a protruding portion of the coupling member 34 is formed on the pile guide 7.

Unlike the general pile foundation construction method, the present invention is configured such that the pile body 3 is penetrated into the gelled sediment 5 by its own weight.

Thus, if the penetration depth is deeper than the depth of the unit pile 3 'or 3", the unit pile 3' or 3" is penetrated to the supporting ground without additionally fixing the unit pile 3 'or 3", and thus, the unit pile 3',3" cannot be connected to each other.

Therefore, when the plurality of unit piles 3',3 ″ are connected to each other by means of the coupling members 34, the unit pile 3' previously penetrated in the foundation 1 is temporarily supported by the pile guide 7.

That is, after the lower unit pile 3' is first inserted into the foundation 1 by its own weight ((a) of fig. 10), the coupling member 34 coupled to the upper end of the previously inserted unit pile 3' is supported by the fixing member 71 of the pile guide 7, and the upper end of the lower unit pile 3' is temporarily fixed to protrude above the ground ((b) of fig. 10).

Then, after the upper pile unit 3 ″ is coupled to the upper end of the previously inserted pile unit 3 '(fig. 10 (c)), the fixing of the fixing member 71 of the pile guide 7 is released, and the vertically connected pile units 3',3 ″ are inserted downward (fig. 10 (d)).

That is, since the coupling member 34 protrudes outside the pile body 3 at the connection portion of the upper and lower unit piles 3',3 ″, the protruding portion of the coupling member 34 is fixed by the fixing member 71 (fig. 10 (b) and (c)), and then after the upper and lower unit piles 3',3 ″, the fixing of the fixing member 71 is released when the pile is inserted into the foundation 1, and the pile is constructed in the order of inserting the pile into the foundation 1 (fig. 10 (d)).

Fig. 11 is a perspective view showing an example of the unit pile.

As shown in fig. 11, the unit piles 3',3 ″ include: a hollow concrete pile body 31; lower covers 32,32a bolted to the lower end of the concrete pile body 31; and upper covers 33,33a coupled to the upper end of the concrete pile body 31 by bolts.

A general pile body such as a PHC pile has a tip ferrule such as a nipple ferrule (mamila ferrule) or a flat plate ferrule (flat ferrule) coupled to a lower portion thereof, and an end cap for protecting a head from an impact such as a knock or a pile driving coupled to an upper portion thereof. When the piles are connected for use, the lower cover and the upper cover for connection are coupled to the pile located in the middle.

Therefore, if a plurality of unit piles 3',3 ″ are piled in a pile foundation by being connected in the longitudinal direction, piles in which the head caps and the end caps, the lower caps and the upper caps, the lower caps and the end caps, and the head caps and the upper caps are combined are manufactured and supplied.

However, since the penetration depth of each of the plurality of pile bodies 3 differs from site to site, it is difficult to accurately predict the needs of the various types of pile bodies described above, and it is difficult to perform inventory management.

Therefore, the front ferrule and the lower cap or the end cap and the upper cap can be selectively coupled to the concrete pile body 31, and the concrete pile body 31 can be coupled to the upper and lower portions thereof by selecting a desired component. Thus, the productivity of the pile body can be improved, and the stock management can be easily performed.

Here, the lower cover 32,32a is not only the lower cover 32 for connection of the intermediate pile, but also includes a front ferrule 32a of the front end.

That is, in case of the lower unit pile 3', the lower cover 32a may be formed of a removable nipple or a plate type ferrule. In particular, the lower cover 32a of the lower end of the lower unit pile 3' may be an expanding type reinforcing plate having a diameter larger than that of the concrete pile body 31.

The upper covers 33,33a are also referred to as upper covers 33 for connecting the intermediate piles, and also include end covers 33a for protecting the heads of the piles.

The lower cover 32,32a or the upper cover 33,33a may be appropriately selected according to need, and coupled to both ends of the concrete pile body 31 by bolts.

Fig. 12 is a sectional view showing a unit pile.

As shown in fig. 12, the pile body 3 is constructed by connecting a plurality of unit piles 3',3 "in a longitudinal direction, and the unit piles 3',3" include: a hollow concrete pile body 31 with upper and lower ends exposed at the center; a plurality of PC nuts 8 embedded in both ends of the concrete pile body 31, respectively; and a PC wire 36 having both ends fixed to the PC nut 8.

The unit pile 3',3 "includes: concrete pile body 31, PC nut 8 and PC steel wire 36.

The concrete pile body 31 is manufactured by circle center molding, and a hollow is formed in the center.

The concrete pile body 31 is manufactured in an exposed state without attaching a separate ferrule or cap to both the upper and lower ends thereof.

Thus, the unit piles 3',3 ″ can be unified into one specification by forming the unit piles 3',3 ″ from the concrete pile body 31 having no additional ferrule or cap attached to both ends.

The unit piles 3',3 ″ can be applied to any portion of the upper end, the lower end, and the middle of the concrete pile.

A plurality of PC nuts 8 are embedded in both ends of the concrete pile body 31, respectively.

The PC nut 8 is used to couple a coupling member 34 or a tip ferrule 37, which will be described later, and an expanding reinforcing plate or an end cap 38 to the end of the unit pile 3',3 ″ by bolts, and the unit pile 3',3 ″ can be used as an intermediate pile, a lower pile or an upper pile according to the kind of member coupled to the end of the unit pile 3',3 ″.

Both ends of the PC wire 36 are coupled and fixed to the upper and lower PC nuts 8, respectively.

The PC steel wires 36 are arranged in the longitudinal direction of the unit piles 3',3 ″ and embedded in the concrete pile body 31.

The PC steel wires 36 are embedded in the concrete pile body 31 so as to be spaced apart from each other.

The PC steel wire 36 is fixed after being tensioned, and a prestress is introduced into the pile body.

In the present invention, the concrete pile is constructed by transporting unit piles 3',3 ″ manufactured in the same specification without a separate ferrule or cap being attached to the ends thereof to the site and then assembling them.

Therefore, only one specification of the unit piles 3',3 ″ need to be produced at the factory, and thus it is possible to improve manufacturing efficiency, to provide economical efficiency, to supply materials efficiently, and to minimize the occurrence of surplus materials. Further, material management can be easily performed on site with the uniform specification of the unit piles 3',3 ″.

Fig. 13 is a perspective view showing a coupling relationship of unit piles by the coupling member.

As shown in fig. 13, the adjacent unit piles 3',3 ″ may be connected to each other by bolting the coupling members 34 to the PC nuts 8.

The upper and lower adjacent unit piles 3',3 "may be connected by a coupling member 34.

At this time, the coupling member 34 is bolt-coupled to the PC nut 8 of each unit pile 3',3 ″.

The coupling member 34 may have various embodiments, and as shown in fig. 13, may be configured by connecting an upper plate 341 and a lower plate 342, which are vertically spaced apart by a predetermined interval, to each other by a support plate 343.

The upper plate 341 and the lower plate 342 may be formed with coupling holes at positions corresponding to the PC nuts 8 of the unit piles 3',3", respectively. After the upper plate 341 and the lower plate 342 are brought into close contact with the end portions of the connected unit piles 3',3", respectively, bolts are coupled through coupling holes in the PC nuts 8 embedded in the end portions of the unit piles 3',3", whereby the adjacent unit piles 3',3 "can be connected to each other.

The coupling member 34 may be made of various materials, and preferably, is made of a metal material having a strong and small deformation.

Fig. 14 is a sectional perspective view showing a unit pile to which a tip ferrule is coupled.

As shown in fig. 14, the front ferrule 37 is bolt-coupled to the PC nut 8 at the lower end of the lowermost unit pile 3'.

In order to easily penetrate into the pile body in the slime and protect the front end during striking, a front end ferrule 37 is provided at the front end.

In this case, a plurality of pile bodies used in one concrete pile foundation construction are used by connecting unit piles 3',3 ″ manufactured to the same specification, and the unit pile 3' located at the lowermost part can be used by attaching another tip ferrule 37 to the lower end thereof on site.

The tip ferrule 37 is coupled to the PC nut 8 embedded in the end of the lowermost unit pile 3' by a coupling bolt (b).

Accordingly, the PHC pile can be formed to correspond to each position without manufacturing the lower end pile to which the tip ferrule 37 is attached in a separate specification.

Further, although not shown in the drawings, the lower end of the unit pile 3' located at the lowermost portion may be reinforced with a front end supporting force by an expandable reinforcing plate having a larger diameter than the concrete pile main body 31 bolted to the PC nut 8 according to the ground conditions.

As shown in fig. 14, 15, and the like, the lower end or upper end outer cylindrical surface of the concrete pile body 31 is formed with a reinforcing strip 39 for protecting the concrete pile body 31.

Fig. 15 is a sectional perspective view showing a unit pile combined with an end cap.

As shown in fig. 15, the upper end of the uppermost unit pile 3 "is bolted with an end cap 38 by means of a PC nut 8.

In order to protect the upper end of the pile body from knocks and the like, an end cap 38 may be incorporated on site at the upper end of the uppermost unit pile 3", if an upper cap is required.

The end cap 38 may be coupled to the PC nut 8 embedded in the end of the uppermost unit pile 3 ″ by coupling a bolt (b).

Thus, the upper end piles to which the upper covers are attached are not manufactured in individual specifications, but the PHC piles conforming to the respective positions are formed using the unit piles 3',3 ″.

FIG. 16 is a perspective view showing the connection between a PC nut and a PC wire according to an embodiment; FIG. 17 is a sectional view of the PC nut and PC wire shown in FIG. 16 in a coupled state; fig. 18 is a cross-sectional view showing a state in which a PC nut and a PC wire are coupled to each other with a hook portion formed thereon.

As shown in fig. 16 to 18, the PC wire 36 has enlarged portions 361 formed at both ends thereof, and at least one or more PC nuts 8 at both ends are formed in a cylindrical shape by closely contacting a pair of a 1 st fixture 81a and a 2 nd fixture 81b, which are spaced apart from each other in a semicircular shape, to the left and right, and are composed of a wire fixing tube 81 formed with a coupling plate 811 at one end of the 1 st fixture 81a and the 2 nd fixture 81b so that the PC wire 36 is passed through and the enlarged portions 361 are coupled; the coupling pipe is formed in a cylindrical shape and coupled to the outside of the wire fixing pipe 81.

In a conventional general PHC pile, a flat plate such as a ferrule or a seal cap is coupled to one end or both ends of a pile body. Therefore, the plate is adjacently provided in a figure-8 shape so that the enlarged portion 361 of the PC steel wire 36 passes through the insertion hole for fixing the tendon and the fixing hole for hooking the enlarged portion 361, and the enlarged portion 361 of one end of the PC steel wire 36 is hooked to the fixing hole, and the plate is pulled, thereby introducing the prestress into the PC steel wire 36.

However, in the present invention, no flat plate is attached to both ends of the unit piles 3',3 ″, and PC nuts 8 are coupled to both ends of the PC wire 36.

At this time, the enlarged portions 361 are formed at both ends of the PC steel wire 36 because there is a trouble that at least one side enlarged portion 361 of the PC steel wire 36 is formed after the PC nut 8 is coupled in order to couple the PC nut 8.

Accordingly, in order to join the PC nut 8 to the PC wire 36 having the enlarged portions 361 formed at both ends thereof at a time, the PC nut 8 is composed of the wire fixing pipes 81 partitioned from the left and right and the joint pipes 82 joining the same.

The wire fixing pipe 81 is formed in a cylindrical shape by closely attaching the 1 st fixing element 81a and the 2 nd fixing element 81b having a semi-cylindrical shape to each other.

A hooking plate 811 is formed at one end of the 1 st anchor 81a and the 2 nd anchor 81b constituting the wire fixing tube 81 such that the enlarged portion 361 of the PC wire 36 is hooked inside the hooking plate 811.

Accordingly, the wire fixing pipe 81 partitioned by the 1 st fixing element 81a and the 2 nd fixing element 81b is coupled to the end of the PC wire 36 having the enlarged portion 361 formed therein, and the coupling pipe 82 can be coupled and fixed to the wire fixing pipe 81.

The coupling pipe 82 has an inner diameter corresponding to the outer diameter of the wire fixing pipe 81, and the cylindrical coupling pipe 82 is coupled to the outside of the wire fixing pipe 81.

A through hole 812 through which the PC wire 36 passes is formed at the center of the hook plate 811 of the wire fixing tube 81.

An internal thread is formed at an inner cylindrical surface of the wire fixing tube 81 so as to be coupled to a bolt (b) coupling the unit piles 3',3 ".

In this case, the coupling pipe 82 outside the wire fixing pipe 81 serves only to join the wire fixing pipes 81 on both sides, and thus, does not need to be fixed to the wire fixing pipe 81.

As shown in fig. 18, in order to prevent the coupling pipe 82 from being detached during the manufacturing process, a hanging part 813 for supporting the coupling pipe 82 may be formed to protrude outside one end of the wire fixing pipe 81.

In order to prevent the coupling pipe 82 and the wire fixing pipe 81 from being separated from each other during the manufacturing process, a screw thread may be formed on an outer cylindrical surface of the wire fixing pipe 81, and an internal screw thread may be formed on an inner cylindrical surface of the coupling pipe 82, so that the wire fixing pipe 81 and the coupling pipe 82 are screw-coupled to each other.

FIG. 19 is a perspective view showing a state where a PC nut and a PC wire are coupled to each other according to another embodiment; fig. 20 is a cross-sectional view showing a state in which the PC nut and the PC wire shown in fig. 19 are coupled to each other.

As shown in fig. 19 and 20, the coupling pipe 82 is formed to be longer than the wire fixing pipe 81 and to extend to the other end side of the wire fixing pipe 81 by a predetermined distance, and the wire fixing pipe 81 and the coupling pipe 82 are screwed to each other.

The PC nut 8 shown in fig. 19 and 20 is an example used when the tension of the PC wire 36 is applied or when the bolt (b) is coupled to the coupling pipe 82 instead of the wire fixing pipe 81 when the unit piles 3',3 ″ are coupled to the coupling member 34.

The tension of the PC wire 36 has a tension for transmitting the external force transmitted to the connection pipe 82 to the PC wire 36, and male and female screws are formed on the outer cylindrical surface of the wire fixing pipe 81 and the inner cylindrical surface of the connection pipe 82, respectively, and are screw-connected to each other.

That is, instead of forming a separate female screw in the wire fixing tube 81, a female screw formed in the coupling tube 82 is applied, and the coupling member 34 is bolted when the unit piles 3',3 ″ are coupled.

At this time, the length of the PC wire 36 is made shorter to the extent that the length of the coupling pipe 82 is extended.

Further, since the length of the PC nut 8 is generally short, when a strong compression force is generated at the PC nut 8, a local front end breakage occurs near the PC nut 8. However, in the present invention, the length of the coupling pipe 82 is extended to increase the fixed length in the concrete pile body 31 of the PC nut 8, thereby preventing the partial front end from being broken as described above.

Fig. 21 is a sectional view showing a state in which a PC nut having a fixing flange formed on a wire fixing pipe is coupled to a PC wire.

As shown in fig. 21 (a) and (b), a fixing flange 814 protruding to the outside of the coupling pipe 82 may be formed at one end or the other end of the wire fixing pipe 81.

In the invention, no additional flat plate is needed, so that the end part of the concrete pile is exposed. Therefore, concentrated stress is generated in the peripheral concrete by the PC nut 8 such as tension of the PC wire 36 or tension generated at the connection portion of the unit piles 3',3 ″, or the PC nut 8 slips and separates from the concrete pile body 31. Accordingly, the PC nut 8 is formed by projecting the fixing flange 814 from the outside of the coupling pipe 82 so that the PC nut can be firmly fixed to the inside of the concrete pile body 31 and the concrete having a wider area can be supported by dispersing stress.

Fig. 21 (a) shows an example in which a fixing flange 814 is formed at the inner end of the wire fixing pipe 81.

At this time, the fixing flange 814 can prevent the sliding of the PC nut 8. And, the tension of the PC steel wire 36 prevents the concrete near the inner end of the PC nut 8 from being locally damaged by pressure. Also, the fixing flange 814 functions as a kind of hooking part, so that the coupling pipe 82 can be prevented from being detached from the wire fixing pipe 81 during the manufacturing process.

Fig. 21 (b) shows an example in which a fixing flange 814 is formed at the outer end of the wire fixing pipe 81.

In this case, local pressure damage of the concrete occurring in the vicinity of the inner end of the PC nut 8 can be prevented.

Further, as described above with reference to fig. 18, in this case, in order to prevent the coupling pipe 82 from being detached from the wire fixing pipe 81 during the manufacturing process, a hanging part 813 for supporting the end of the coupling pipe 82 may be formed to protrude outside one end of the wire fixing pipe 81.

Also, by forming the fixing flange 814, the PC nut 8 functions as a shear pin, so that the PC nut 8 is structurally integrated with the concrete pile body 31, reinforcing the end portions of the unit piles 3',3 ″.

As shown in fig. 22, a fixing flange 821 embedded in the concrete pile body 31 may be formed to protrude from the outside of the coupling pipe 82.

The fixing flange 821 integrates the PC nut 8 with the concrete pile body 31, reinforces the ends of the unit piles 3',3 ″ and prevents local damage of concrete.

Claims

1. A construction method of a non-dumping pile foundation suitable for silt gelation, which is characterized in that,

in order to penetrate a pile body (3) into a foundation (1), the method comprises the following steps:

(a) measuring the position of the pile body (3) to be constructed;

(b) rotatably injecting a stirring device (6) into a construction site of a pile body (3) until a foundation is supported to soften the silt in the foundation (1), spraying a gelling agent to the stirring device (6), and stirring the softened silt and the gelling agent to gelatinize the silt (gel);

(c) removing the stirring device (6), and penetrating the pile body (3) into the gelled sediment (5) by means of self weight to enable the pile body to be arranged on a supporting foundation; and

(d) curing the gelled sediment (5) and fixing the pile body (3).

2. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 1,

in the step (b), a space (12) for removing the upper sand from the ground to a predetermined depth is formed at the construction site of the pile body (3).

3. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 2,

a soil discharging and digging part (61) formed with a continuous screw (611) for discharging soil is arranged at the lower part of the stirring device (6), and a stirring part (63) formed with a stirring blade (631) is arranged at the upper part of the soil discharging and digging part (61).

4. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 3,

a reverse circulation part (62) is further formed between the soil discharging excavation part (61) and the stirring part (63) of the stirring device (6), and a non-soil discharging reverse thread (621) arranged in the opposite direction of the continuous thread (611) for soil discharging is formed in the reverse circulation part.

5. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 2,

the stirring device (6) comprises: a bolt sleeve (64) for soil removal, which is provided with a continuous screw (641) for soil removal on the outer cylindrical surface and is used for digging and discharging the upper silt of the construction site of the pile body (3) to form a space part (12); and a non-discharging stirring rod (65) which is provided with a stirring blade (651) on the outer cylindrical surface, is formed in the discharging bolt sleeve (64) in a way of moving up and down and rotating, is used for softening the silt at the lower part of the space part (12), and is stirred with the gelatinizing agent.

6. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 2,

a torque sensor for measuring a rotation torque of the stirring device (6) is provided at an upper end of the stirring device (6), and the stirring work is repeatedly performed until a torque value measured by the torque sensor drops to a set target torque value or less in the step (b).

7. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 1,

a nozzle (633) for jetting at least one of high-pressure air and high-pressure water is formed in the stirring device (6), and the silt is softened by the high-pressure jetting through the nozzle (633).

8. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 1,

an expansion reinforcing plate (35) having a larger diameter than the main body of the pile body (3) is joined to the lower end of the pile body (3).

9. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 8,

in the step (c), the pile body (3) is constructed by connecting a plurality of unit piles (3', 3') in a longitudinal direction.

10. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 9,

the plurality of unit piles (3', 3') are connected to each other by a connecting member (34), and the connecting member (34) is formed to protrude to the outside of the pile body (3).

11. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 10,

in the step (c), a pile guide (7) for guiding penetration of the unit pile (3',3") is provided on an upper ground portion of a construction site of the pile body (3), and a fixing member (71) for selectively hooking and supporting a protruding portion of the coupling member (34) is formed on the pile guide (7).

12. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 9,

the unit pile (3', 3') comprises:

a hollow concrete pile body (31);

a lower cover (32,32a) coupled to a lower end of the concrete pile body (31) by a bolt; and

and an upper cover (33,33a) that is bolted to the upper end of the concrete pile body (31).

13. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 1,

the gelling agent comprises 35 to 60 wt% of an inorganic binder, 20 to 45 wt% of water and 0.15 to 7 wt% of a dispersant.

14. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 13,

the gelling agent is added in an amount of 150 to 320 parts by weight relative to 100 parts by weight of the site silt.

15. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 13,

the weight of the inorganic binder relative to the weight of the overall inorganic binder comprises SO₃7 to 15% by weight of Al₂O₃8 to 15 wt% and CaO45 to 55 wt%.

16. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 1,

the pile body (3) is formed by connecting a plurality of unit piles (3', 3') along the longitudinal direction,

the unit pile (3', 3') comprises:

a hollow concrete pile body (31) with an upper end and a lower end exposed is formed in the center;

a plurality of PC nuts (8) embedded in both ends of the concrete pile body (31); and

and a PC wire (36) having both ends coupled and fixed to the PC nut (8).

17. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 16,

the adjacent unit piles (3', 3') are connected to each other by bolting the joint member (34) to the PC nut (8).

18. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 16,

at the lower end of the unit pile (3') located at the lowermost portion, a front ferrule (37) or an expanding reinforcing plate is bolt-coupled with a PC nut (8).

19. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 16,

at the upper end of the uppermost unit pile (3'), an end cap (38) is bolt-coupled with a PC nut (8).

20. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 16,

an enlarged part (361) with enlarged diameter is formed at both ends of the PC steel wire (36),

at least one of the PC nuts (8) at both ends is composed of a cylindrical wire fixing pipe (81) formed by a pair of left and right semi-cylindrical 1 st fixing pieces (81a) and 2 nd fixing pieces (81b) which are separated and closely contacted with each other, and a cylindrical connecting pipe (82) connected with the outside of the wire fixing pipe (81), wherein one end of the 1 st fixing piece (81a) and one end of the 2 nd fixing piece (81b) are provided with a hanging plate (811) which enables the PC steel wire (36) to penetrate through and hang an expansion part (361).

21. The method of constructing a non-discharging pile foundation suitable for gelation of silt according to claim 20,

the connecting pipe (82) is formed to be longer than the wire fixing pipe (81), is formed to extend to the other end side of the wire fixing pipe (81) by a predetermined length, and is connected to the connecting pipe (82) by a screw.

22. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 20 or 21,

a fixing flange (814) protruding to the outside of the coupling pipe (82) is formed on the outside of one end or the other end of the wire fixing pipe (81).

23. The method for constructing a non-discharging pile foundation suitable for gelation of silt according to claim 21,

a fixing flange (821) embedded into the concrete pile main body (31) is formed on the outer side of the connecting pipe (82).