KR102149894B1 - Method for pile construction - Google Patents

Abstract

The present invention relates to a pile construction method of constructing a pile after stirring the soil of the pile construction site, and the pile construction method according to the present invention includes a ground stirring step (S10) of spraying a filler while stirring the ground and the ground stirring step (S10). ) It is a technical feature that comprises a pile construction step (S20) of constructing a pile on the ground stirred in. Accordingly, it is possible to stably construct a high-depth pile regardless of the state of the ground, and the peripheral friction and tip bearing capacity of the installed pile can be improved to secure high support, and the construction is simple and the process period is shortened.

Description

Pile construction method {METHOD FOR PILE CONSTRUCTION}

The present invention relates to a method of constructing a pile in the ground, and more particularly, to a pile construction method of constructing a pile after stirring the soil of the pile construction site.

In general, in order to construct a structure, a method of securing support strength by constructing a pile in the ground is used. Construction methods for such piles include direct punching and buried construction.

The direct hitting method is a method of physically hitting the head of a pile to enter the ground, and has the advantage of low construction cost and freedom from the depth limit, but it is difficult to construct on a soft ground such as a landfill. Interruptions are often broken, construction is difficult depending on the nature of the ground, and construction is difficult in urban areas due to high noise.

The burial method includes excavation and topography of the ground, installation of casing, removal of slime (aerating), primary grouting to strengthen the contact force between the end of the pile and the ground, pile construction, casing removal, plowing, and secondary grouting by spraying water and cement. The process is proceeded in the order of arranging the pile head, and there are advantages in that there are few restrictions depending on the strata, low noise and low vibration, and that there are few restrictions on the properties of the ground that can be applied compared to the direct drilling method. However, it is difficult to remove the casing due to jamming (jammimg, a phenomenon in which soil flows between the end of the pile and the casing due to the pressure of the surrounding ground), and if the depth is about 45m or more, the leader of the construction equipment should be 45m or more to install the casing. It must be made, but construction is practically impossible due to safety problems such as construction risk. In addition, there is a problem in that it is difficult to apply the buried method because it is difficult to inject and pull out the casing in a highly viscous ground such as mud. In addition, even if cement milk is injected, since it is not uniformly formed on the outer surface of the pile, there is a problem in that the frictional force with the surrounding ground is low, and the treatment of the soiled soil is required.

The present invention has been conceived to solve the above problems, and the problem to be solved in the present invention is to provide a method of constructing a pile that does not require a soil treatment, a high-depth construction is possible, and can be constructed on a soft ground.

The pile construction method according to the present invention is characterized in that it comprises a ground stirring step of spraying a filler while stirring the ground and a pile construction step of constructing a pile on the ground stirred in the ground stirring step.

According to the pile construction method according to the present invention, it is possible to stably construct a high depth pile regardless of the state of the ground.

In particular, stable pile construction is possible on soft ground such as a landfill.

In addition, high bearing power can be secured by improving the peripheral friction and tip bearing power of the installed pile.

In addition, construction is simple and the process period is shortened.

1 is a flow chart of a pile construction method according to the present invention
Figure 2 is a drilling device used in the pile construction method according to the present invention
3 is a stirring part of the drilling device
Figure 4 is a state in which the pile construction is completed by the method of Example 1 by mounting the expansion reinforcing plate at the bottom of the pile

Hereinafter, a file construction method according to the present invention will be described in more detail through the accompanying drawings.

1 is a flow chart of a pile construction method according to the present invention. The pile construction method according to the present invention comprises a ground stirring step (S10) and a pile construction step (S20).

The ground agitation step (S10) is a step of agitating the ground by using the ceiling plant value, and the agitation diameter should be larger than the diameter of the pile constructed in the pile construction step (S20), and the filler is sprayed when the ground is stirred. The agitation of the ground may proceed to the target depth or may be stirred shallower than the target depth. The pile construction method according to the present invention is optimized when the length of the pile is 5 times or more compared to the diameter of the pile.

Figure 2 is a drilling device used in the pile construction method according to the present invention, Figure 3 shows a stirring part of the drilling device. The drilling unit is composed of a stirring unit 10, a reader 20, a backstage 30, a generator 40, etc., and the stirring unit 10 of the drilling device is a bite 12, a stirring blade 14 , It is configured to include a discontinuous spiral wing (16) and ejection hole (18).

The bite 12 is a component that is mounted on the tip of the stirring unit 10 to perforate the ground, and the ground is crushed by the rotation of the bite 12.

The stirring blade 14 is a component that agitates the ground crushed by the bite 12, and by the stirring of the stirring blade 14, it becomes easy to mix the filler and the ground later.

Spiral blade 16 is also a component that stirs the ground crushed by the bite 12. If the stirring blade 14 is formed in the transverse direction to perform transverse agitation of the ground, the spiral blade 16 Longitudinal agitation is carried out. In general, when agitating the ground using the stirring unit 10, the stirring unit 10 is not unilaterally inserted and rotated, but the ground is stirred while moving the stirring unit 10 up and down. At this time, the spiral blade 16 By this, the ground is stirred up and down. In the present invention, since the soil is not covered with soil, the spiral wing 16 does not close the cross-sectional area in which the ground is perforated (if closed, the soil is covered along the spiral wing 16, or up and down by the boundary of the spiral wing 16). It cannot be mixed with} It is formed discontinuously, and a stirring hole 17 that becomes a passage through which soil and sand moves up and down may be formed. The stirring hole 17 is preferably arranged in a zigzag shape along the axis of the stirring unit 10 to increase the efficiency of soil stirring.

The ejection hole 18 is a passage for ejecting the fluid flowing through the shaft of the stirring unit 10 into the ground, and the fluid may be water or a filler according to a specific shape of the stirring method. The filler is a mixture of a binder containing a solidifying agent, water, and cement, and is agitated with soil to form a hardened area around the pile to be constructed in the pile construction step (S20), thereby improving peripheral friction. In the case of soft ground, it is preferable in terms of constructability and structural safety that the filler is mixed in the form of a mixture of 30 to 35 ℓ by mixing 1 to 2 kg of solidifying agent and 70 to 100 kg of binder in water for 1㎥ of soil.

The solidifying agent is a material exhibiting effects such as increasing load-bearing capacity and reinforcing the ground by imparting solidifying power to the ground. In one embodiment, calcium chloride 22.4 to 35.7 parts by weight, ammonium chloride 12 to 28 parts by weight, magnesium chloride 21.42 to 34.68 parts by weight , Magnesium sulfate 1.2 to 7 parts by weight, Almic acid soda 8 to 13 parts by weight, Ligreen sulfonate 4 to 10 parts by weight, magnesium stearate 2.5 to 3.5 parts by weight, 1 to 2 parts by weight of divalent iron compounds such as iron sulfate Can be.

When the ground is stirred to the target depth in the ground stirring step (S10), there are two methods of mixing water or fillers.

The first is a method of stirring while continuously spraying the filler material from the surface to the target depth.

The second is a method of stirring while spraying only water from the ground surface to a point at a predetermined ratio of the target depth, and spraying the filler material from the point at a predetermined ratio of the target depth to the target depth. The point at which the predetermined ratio of the desired target depth is 2/3 of the target depth. According to the second method, there is an effect that construction costs can be reduced by reducing the filler material without causing the phenomenon that the floating soil mixed with the soil and the solidifying agent is reclaimed on the ground.

In the case of stirring the ground shallower than the target depth in the ground agitation step (S10), for example, even when the ground is stirred only up to 2/3 of the target depth, the method of mixing water or filler is largely divided into two types.

The first is a method of stirring while continuously spraying the filler material from the surface to the point where the stirring ends, and the second is a method of stirring while spraying water from the surface to a certain depth, and spraying the filler material after a certain depth. .

The pile construction step (S20) is a step of constructing a pile on the ground stirred in the ground stirring step (S10), and the embodiment is determined according to how the ground was stirred in the ground stirring step (S10).

First, the pile construction step (S20) when the ground is stirred to the target depth in the ground stirring step (S10) will be described.

Since the ground is stirred to the target depth, the end of the pile is easily constructed to the target depth. At this time, since the pile construction alone may not obtain sufficient tip bearing capacity, after the pile is constructed to the target depth, hit the head of the pile so that the pile can be firmly supported on the ground. These hits are referred to as “gyeongta” in the relative meaning of direct hitting, in which piles are constructed as hits on the hard ground, and “gyeongta” does not inflict the same level of hitting as putting piles on the ground. That is, the first embodiment of the pile construction method according to the present invention is configured to further include a pile hitting step (S30) of hitting the pile after constructing the pile to the target depth in the pile construction step (S20).

Example 1 is easy to penetrate after installing the expansion reinforcing plate at the lower end of the pile to improve the tip bearing capacity. The expansion reinforcement plate is a metal plate having a diameter larger than the diameter of the pile at the lower end of the pile, and the tip bearing capacity is greatly improved due to the expansion reinforcement plate. The expansion reinforcing plate may have a central hole. When the extension reinforcing plate is installed at the bottom of the pile, it is only applied to the buried method because the direct punch method is difficult. The larger the diameter of the expansion reinforcement plate is, the more advantageous it is to improve the tip bearing capacity. However, if it is drilled with a diameter wider than the diameter of the pile, it is difficult to maintain the verticality of the pile due to the empty space area. The diameter is designed and applied to a limit. For example, it is difficult to make the diameter of the expansion reinforcement plate larger than the diameter of the pile by 10 to 15 cm or more with the current embedding method. On the other hand, the method of Example 1 is a very advantageous method for using an expanded reinforcing plate because the ground can be stirred in a wider range than the pile diameter.

Figure 4 shows a state in which the pile construction is completed by the method of Example 1 by mounting the expansion reinforcing plate at the bottom of the pile. The friction force with the ground is very high due to the enlarged pile area created by the filler injection and stirring. For reference, the tip bearing capacity is usually calculated based on the diameter of the expansion reinforcing plate, and in the case of the construction as shown in FIG. 4, the overall support of the pile is greatly improved due to the application of the wide expansion reinforcing plate.

Next, the pile construction step (S20) when the ground is stirred below the target depth in the ground stirring step (S10) will be described.

Since the ground is agitated below the target depth, the end of the pile is easily constructed up to the point where the ground is agitated (hereinafter referred to as “stirring depth”). However, since the ground is not stirred up to the target depth, the pile is constructed using the direct drilling method. That is, the second embodiment of the pile construction method according to the present invention further includes a pile direct hitting step (S40) of constructing the pile to the target depth by hitting the pile by the direct punching method after installing the pile to the stirring depth in the pile construction step (S20). It consists of including.

At this time, since construction is not easy to increase the length of the pile to the target depth from the beginning, the length of the first pile (hereinafter referred to as'first pile') should be the same as the distance from the ground surface to the depth of stirring. , After installing the first file, it is better to connect another file (hereinafter referred to as'connected file') to the first file, and then hit the head of the connected file by direct hitting method. That is, the file direct hitting step (S40) may further include a file linking step (S42) of linking the initial file and the linked file.

The pile construction method according to the present invention enables stable high-depth pile construction regardless of the ground condition, and particularly has a remarkable effect on soft ground.

In addition, since soil and fillers form a reinforced area on the main surface of the pile, the peripheral friction is increased, and the pile with a reinforcement plate larger than the pile diameter can be easily inserted into the ground, so the tip bearing capacity can be easily increased. Can significantly improve the overall support. Therefore, assuming the same bearing capacity, the length of the pile used can be shortened compared to the conventional buried method or the direct punching method (when inserting the pile into the ground with the pile construction method according to the present invention, the peripheral friction force per unit length of the pile is embedded This is because when the construction method or direct punch method is applied, it is greater than the peripheral friction per unit length of the pile).

In addition, it is possible to remarkably improve the bearing capacity of the pile against the sub-friction force (the lower friction force acting on the pile due to the settlement of the soft layer when consolidation occurs due to lower groundwater level around the pile, mainly placed on the viscous ground, and embankment load).

In addition, it is easy to change the construction according to the design conditions because it is possible to increase the peripheral friction force by the pile just by increasing the stirring diameter.

In addition, there is no problem of topography treatment that occurs in the conventional embedding method.

S10 ground stirring step S20 pile construction step
S30 file putt step S40 file direct hit step
S42 file association steps
10 Stirring part 12 bytes
14 Stirring blade 16 Spiral blade
18 Blowout 20 Leader
30 backstage 40 generator

Claims (9)

Ground stirring step (S10) of spraying the filler while stirring the ground, and
A pile construction method comprising a pile construction step (S20) of constructing a pile on the ground stirred in the ground stirring step (S10),
The ground stirring step (S10) is a bite 12 for crushing the ground, a stirring blade 14 for agitating the crushed ground in a transverse direction, a stirring blade 16 for stirring the crushed ground in a longitudinal direction, and a fluid It is carried out by a perforation device having a stirring portion 10 consisting of a jet hole 18 for jetting into the ground,
The stirring unit 10 stirs the ground while moving up and down,
A stirring hole 17 is formed in the spiral wing 16 so that soil can be moved up and down through the stirring hole 17,
The filler is a mixture of a binder containing a solidifying agent, water and cement,
The solidified material is calcium chloride 22.4 to 35.7 parts by weight, ammonium chloride 12 to 28 parts by weight, magnesium chloride 21.42 to 34.68 parts by weight, magnesium sulfate 1.2 to 7 parts by weight, soda almic acid 8 to 13 parts by weight, ligreen sulfonate 4 to 10 parts by weight, 2.5 to 3.5 parts by weight of magnesium stearate, and 1 to 2 parts by weight of a divalent iron compound, characterized in that the pile construction method.
The method according to claim 1,
The ground stirring step (S10) is a step of stirring the ground to a target depth,
The pile construction step (S20) is a step of constructing a pile to a target depth,
A pile construction method, characterized in that it further comprises a pile hitting step (S30) hitting the pile after the pile construction step (S20).
The method according to claim 2,
The ground stirring step (S10) is a pile construction method, characterized in that stirring the ground while continuously spraying the filler from the ground surface to the target depth.
The method according to claim 2,
The ground stirring step (S10) is characterized in that the ground is stirred while spraying water from the ground surface to the point of 2/3 of the target depth, and the ground is stirred while spraying the filler from the point of becoming 2/3 of the target depth to the target depth. Pile construction method.
delete The method according to claim 1,
The ground stirring step (S10) is a step of stirring the ground up to 2/3 of the target depth,
The pile construction step (S20) is a step of constructing a pile up to 2/3 of the target depth,
After the pile construction step (S20), the pile construction method further comprises a direct hitting step (S40) of striking the pile to construct the target depth.
The method of claim 6,
The pile construction method (S40) further comprises a pile connection step (S42) of connecting the connection file to the first pile constructed on the ground.
delete The method according to claim 1,
The filling material is a pile construction method, characterized in that the solidifying agent 1 ~ 2 ㎏ for 1㎥ of soil and mixed in water with a binder 70 ~ 100kg in the form of a mixture of 30 ~ 35ℓ.

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