KR101224440B1 - Construction method of screw file - Google Patents

Abstract

The present invention relates to a screw pile construction method, comprising: a first step of forming a perforation by drilling a buried layer located on the top layer of the ground using a perforator; Inserting a screw pile into the perforation and rotating the screw pile while injecting air through the discharge hole at the end of the screw pile to drill a portion of the ground under the buried layer; The grouting solution is discharged through the grouting hole of the rotating screw drive to grind the ground to determine the support layer by using the torque value of the screw pile generated by the resistance of the ground, and then inject the screw pile to the support layer. A third step; A fourth step of increasing the supporting force of the support layer for supporting the screw pile inserted therein; A fifth step of further penetrating the screw pile to a predetermined depth while grouting the ground when the rotational driving of the screw pile is restored; By including it, it is possible to improve the tip bearing capacity of the screw pile against the ground even if the screw pile is inserted into the ground only to a certain depth, thereby reducing the time and effort required to penetrate the screw pile into the ground. .

Description

Screw pile construction method {CONSTRUCTION METHOD OF SCREW FILE}

The present invention relates to a screw pile construction method, and more particularly, to a screw pile construction method that can improve the tip bearing capacity of the screw pile to the ground even if the screw pile only penetrates the ground to a certain depth.

Generally, in case of building a high-rise building or a reinforced concrete structure, a basic construction is carried out by putting a PHC file or an H-type beam on the ground in order to solidify the foundations, and construction of the above- It is a very important construction for building structures.

As a method of constructing the above-mentioned file, a piling method and an excavation method have been introduced.

The method of installing the electron is as follows: a method in which the hammer of the weight is elevated by using a hoisting rope installed on the upper part of a leader installed vertically in the crawler traveling device, So that the pile is poured into the ground while the hammer is raised and lowered.

In the latter excavation method, the screw pile mounted on the pile connection part is rotated to excavate the ground to form a pile ball, and then the screw pile is reversely rotated and removed from the drilled pile ball, and then the pile is inserted into the pile ball, or Intrusive screw pile is used to reinforce the foundation of the ground.

However, when the foundation of the ground using the screw pile is carried out, it is necessary to inject the screw pile to the rock layer of the ground to increase the tip bearing capacity of the screw pile on the ground. There is a problem that the effort and the cost of injecting the screw pile are doubled.

The purpose of the present invention is to solve the problems described above, even if the screw piles into the ground only a certain depth to improve the end bearing capacity of the screw piles on the ground, accordingly the time and effort required to penetrate the screw pile into the ground It is to provide a screw pile construction method that can be significantly reduced.

The present invention was created to achieve the object of the present invention as described above, the screw pile construction method according to an embodiment of the present invention, to form a perforation by drilling a buried layer located on the top layer of the ground using a perforator A first step; Inserting a screw pile into the perforation and rotating the screw pile while injecting air through the discharge hole at the end of the screw pile to drill a portion of the ground under the buried layer; The grouting solution is discharged through the grouting hole of the rotating screw drive to grind the ground to determine the support layer by using the torque value of the screw pile generated by the resistance of the ground, and then inject the screw pile to the support layer. A third step; A fourth step of increasing the supporting force of the support layer for supporting the screw pile inserted therein; A fifth step of further intruding the screw pile to a predetermined depth while grouting the ground when the rotational driving of the screw pile is restored; Characterized in that configured to include.

Here, in the fourth step, the screw pile may be spaced apart from the ground at regular intervals, and then rotated forward to increase the bearing capacity of the ground by allowing the grouting liquid discharged to the ground to be stirred with the ground.

In the fourth step, the screw pile may be drawn out a predetermined distance from the ground and then repeatedly inserted therein to increase the bearing capacity of the ground.

In addition, the fourth step may increase the bearing capacity of the ground by compacting the ground by allowing the air to be discharged through the discharge hole of the screw pile.

In addition, between the second step and the third step may include a step of fixing the new screw pile to the tip of the screw pile exposed to the upper side of the ground.

After the fifth step, the grouting solution may be filled and grouted in the space between the inside of the screw pile, the ground into which the screw pile is inserted, and the screw pile into the ground.

The method may further include installing a head cleaning plate at the tip of the screw pile exposed to the ground.

The screw pile construction method according to the present invention improves the tip bearing capacity of the screw pile on the ground even if the screw pile is inserted into the ground only to a certain depth, thereby significantly reducing the time and effort required to penetrate the screw pile into the ground. It has an effect.

1 to 5 is a plan view sequentially showing a method for constructing a screw pile on the ground according to an embodiment of the present invention,
6 is a plan view showing an example of increasing the holding capacity of the sand gravel layer using a screw pile,
7 is a plan view showing another example of increasing the holding capacity of the sand gravel layer using a screw pile,
8 is a plan view showing another example of increasing the holding capacity of the sand gravel layer using a screw pile,
9 is a construction flow chart sequentially describing a screw pile construction method according to an embodiment of the present invention.

Hereinafter, a screw file according to the present invention will be described in detail with reference to the accompanying drawings.

1 to 5 are plan views sequentially showing a method of constructing a screw pile in the ground according to an embodiment of the present invention, Figure 6 is a plan view showing an example of increasing the bearing capacity of the sandy gravel layer using the screw pile 7 is a plan view showing another example of increasing the support capacity of the sand gravel layer using a screw pile, Figure 8 is a plan view showing another example of increasing the support capacity of the sand gravel layer using a screw pile, 9 is a construction flow chart sequentially describing a screw pile construction method according to an embodiment of the present invention.

As shown in Figures 1 to 5, the screw pile construction method according to an embodiment of the present invention by using a punching machine 300 to drill the buried layer (4) located on the top layer of the ground to form a punching portion (4a) The first step is to insert the screw pile into the perforations (4a) and to drive the screw pile while injecting air through the discharge hole 120 of the screw pile end ground 3 for the lower side of the buried layer (4) The second step of drilling a part of the support layer, and the grouting liquid is discharged through the grouting hole 130 of the rotating screw drive to grind the ground while utilizing the torque value of the screw pile generated by the resistance of the ground support layer A third step of injecting the screw pile up to the support layer after the determination; A fourth step of increasing the supporting force of the support layer for supporting the screw pile inserted therein; And a fifth step of further penetrating the screw pile to a predetermined depth while grouting the ground when the rotational driving of the screw pile is restored.

First, look at the structure of the screw pile used in the screw pile construction method according to an embodiment of the present invention.

The screw pile is formed with a hollow inside and communicates with the hollow at one end, the discharge hole having a smaller diameter than the hollow is formed through the tubular rod portion formed so as to be spaced apart a predetermined distance along the circumferential direction a plurality of grouting holes on the side; And a spiral portion formed and attached to the outer circumferential surface of the rod portion in a spiral shape in the longitudinal direction of the rod portion.

The rod part 100 is formed at the center of the rod part 100 in the longitudinal direction so as to facilitate the piercing operation by ejecting a fluid such as water or air through the end of the rod part 100 when the ground is punctured, And a hollow 110 for forming a traveling path is provided.

Since the ground is weakened when air is injected into the ground through the hollow 110, the piercing operation can be performed more smoothly. At the same time, the perforated soil can be moved quickly to the spiral part 200 to be described later, .

The hollow 110 is used as an air or fluid injection path in the ground penetration and pile installation steps and as an injection path of the grouting solution in the grouting step.

In addition, at one end of the rod part 100, a discharge hole 120 is formed in communication with the hollow 110 to discharge a fluid such as air or moisture to the outside, and a screw pile is formed on the side of the rod part 100. A plurality of grouting holes 130 are formed to penetrate the grouting liquid while allowing the grouting liquid to be injected into the perforated ground.

The outer circumferential surface of the rod portion 100 is provided with a spiral portion 200 is formed in a spiral shape and fixedly coupled, the spiral portion 200 is easily inserted into the ground by the rotation of the ground portion when the ground drilling In addition to the role of increasing the diameter of the perforation of the ground to be drilled by the screw pile and to improve the principal surface friction of the screw pile on the ground.

A screw file construction method using a screw file having such a configuration according to an embodiment of the present invention is as follows.

In general, the ground is sequentially laminated from the top of the rock layer (1) located at the bottom of the sand sand layer 2, the silt sand layer (3), the buried layer (4), first, as shown in FIG. By using a separate punching machine, the embedding layer 4 having a depth of about 5 m is drilled to form a punching portion 4a having a constant diameter (8 inches in this embodiment).

As shown in FIG. 2, the screw pile is inserted into the drilling portion 4a and the air is blown through the discharge hole 120 at the end of the screw pile to rotate the screw pile at a speed of about 14 RPM, thereby filling the buried layer 4. Perforate the silt sand layer (3) located in the lower layer.

The rotation speed of rotating the screw pile can be adjusted according to the hardness of the silty sand layer 3. If the hardness of the silt sand layer 3 is high, the rotation speed is increased, and if the hardness is low, the screw file is not damaged by reducing the rotation speed. It is desirable to drill while rotating within the range.

After the screw pile has been punched to a certain depth into the silt sand layer 3, a new screw file is fixedly coupled to the tip of the screw file exposed above the ground.

Although a method of fixedly coupling the new screw pile to the screw pile can be variously implemented, in this embodiment, a flange-shaped member is provided at the tip of the screw pile, and the flange-shaped member is fastened to each other using bolts and nuts. The screw pile is coupled to each other by the method.

As shown in FIG. 3, after the screw pile drills the silty sand layer 3 to a predetermined depth, grouting is carried out through the grouting hole 130 of the screw pile which is rotated by injecting grouting liquid through the hollow 110. The ground is grounded to the upper side of the sand grind layer 2 while grouting the ground by discharging the liquid.

Then, the sand gravel layer 2 increases the supporting force so as to stably support the screw pile in which the sand gravel layer 2 is inserted.

As shown in FIG. 6, in the method of increasing the supporting force of the sand grind layer 2, the screw pile is spaced apart from the ground at regular intervals and then rotated forward to discharge the grouting liquid to the ground. By stirring with the grouting liquid is filled in the empty space above the sand grind layer 2 can increase the bearing capacity.

As shown in FIG. 7, the screw pile may be pulled out at a predetermined distance from the ground and then repeatedly inserted into the sand pile layer 2 to increase the bearing capacity.

In addition, as shown in FIG. 8, by allowing air to be discharged through the discharge hole 120 of the screw pile, the upper part of the sand grind layer 2 may be compacted to increase the bearing force.

After increasing the top of the sand grind layer 2 by the above-described method, as shown in FIG. 4, the sand pile layer 2 to a depth where the screw pile no longer penetrates while grouting by rotating the screw pile again. The screw pile is stably supported on the ground by intruding into it.

The grouting liquid is filled in the space between the inside of the screw pile and the ground into which the screw pile is inserted and the screw pile into the ground, thereby increasing the supporting strength of the screw pile and the ground.

In addition, as shown in Figure 5, when the screw pile is completely penetrated into the ground and the front end of the screw pile exposed to the outside of the ground is stably supported, a separate head cleaning plate 140 is installed at the end of the screw pile This will complete the foundation work of the ground.

[Table 1] below shows the results of the load pile analysis and the total settlement and residual settlement after the construction of the screw pile on the ground by the screw pile construction method according to an embodiment of the present invention.

Load
maximum
weight
(ton)
final
Settlement
(mm)
Analysis method by yield load (load-strain)
P-S
logP-logS
S-logt P-dS /
d (logt) Yield
Ton



61.25



56.33 surrender
weight
(ton) Settlement
(mm) surrender
weight
(ton) Settlement
(mm) surrender
weight
(ton) Settlement
(mm) surrender
weight
(ton) surrender
weight
(ton)
52.5
8.41
52.5
8.41
52.5
8.41
52.5
52.5

The screw pile used in this experiment is 76.3 mm in rod diameter, 16.3 m penetration length, 152.6 mm screw diameter (install only 10.6 m in the lower part of the rod). The result was obtained.

As shown in Table 1, the yield load is 52.5 tons according to the analysis method of PS, LogP-LogS, S-Logt, and P-dS / d (logt) as the yield load of the screw pile, and the safety factor (2.0) The allowable bearing capacity is considered to be 26.25ton.

In the analysis method based on the settlement amount, the load at the total settlement (25.4mm) was 55.5tons, and the allowable bearing capacity considering the safety factor (1.5) was 37.0tons, and the load at the residual settlement (12.7mm) At 54.5 tons, the allowable bearing capacity considering the safety factor (2.0) is 27.25 tons.

As a result of this test, the allowable bearing capacity of screw pile was 26.25ton, the minimum value among the above analysis results, which satisfies the maximum pull capacity of 7ton.

As a result of this test, the allowable bearing capacity of screw pile is 26.25ton, which is the minimum value among the above analysis results.

Although the screw file of the present invention has been described with reference to the preferred embodiments, it should be understood that the technical scope of the present invention is not limited thereto.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. There is no saying.

1: rock bed 2: sand pile
3: silt sand layer 4: buried layer
100: rod 110: hollow
120: discharge hole 130: grouting ball
200: spiral 300: perforator

Claims (7)

A first step of perforating the buried layer located on the top layer of the ground using a perforator to form perforations;
Inserting a screw pile into the perforation and rotating the screw pile while injecting air through the discharge hole at the end of the screw pile to drill a portion of the ground located below the buried layer;
The grouting liquid is discharged through the grouting hole of the rotating screw drive to grind the ground to determine the support layer using the torque value of the screw pile generated by the resistance of the ground, and then to inject the screw pile to the support layer. A third step;
A fourth step of increasing the supporting force of the support layer for supporting the screw pile inserted therein;
A fifth step of further penetrating the screw pile to a predetermined depth while grouting the ground when the rotational driving of the screw pile is restored;
Wherein the screw file has a plurality of screw holes. The method of claim 1,
The fourth step is a screw pile construction method, characterized in that to increase the bearing capacity of the ground by allowing the grout liquid discharged to the ground to be stirred with the ground after a predetermined interval spaced apart from the ground. The method of claim 1,
The fourth step is a screw pile construction method, characterized in that to increase the bearing capacity of the ground by repeatedly performing the process of injecting the screw pile after drawing a certain distance from the ground. The method of claim 1,
The fourth step is a screw pile construction method, characterized in that to increase the bearing capacity of the ground by compacting the ground by allowing the air to be discharged through the discharge hole of the screw pile. 5. The method according to any one of claims 1 to 4,
And fixing the new screw file to the tip of the screw file exposed above the ground between the second step and the third step. The method of claim 5,
After the fifth step, a grouting solution is filled in the space between the inside of the screw pile and the ground into which the screw pile is inserted and the screw pile into the ground, thereby increasing the load of the screw pile itself. Screw pile construction method. The method according to claim 6,
The screw pile construction method further comprises the step of installing a head cleaning plate on the front end of the screw pile exposed to the ground outside.

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