KR101288885B1 - Micro steel pipe pile for increasing load carrying capacity and construction method thereof - Google Patents

Abstract

The present invention relates to a micro-steel pipe pile used as a pile to stably support the structure, in particular to a micro-steel pipe pile and its construction method that can increase the bearing capacity and horizontal resistance capacity while preventing relaxation after insertion It is about.
According to a preferred embodiment of the micro-steel pipe pile for increasing the bearing capacity of the present invention, a plurality of or more turning screws are formed at regular intervals in the lower portion of the lower portion, the steel pipe pile body is provided with the bottom surface is closed, the steel pipe pile body Filler discharge hole is formed between the adjacent turning screw penetrating the steel pipe pile body, stirring means for stirring the filler discharged to the filler discharge hole during rotational penetration of the steel pipe pile body is located around the filler discharge hole It is characterized by that.

Description

Micro steel pipe pile for increasing load carrying capacity and construction method

The present invention relates to a micro-steel pipe pile used as a pile to stably support the structure, and more particularly to a micro-steel pipe pile and a construction method that can increase the bearing capacity and horizontal resistance while preventing relaxation after insertion will be.

In general, the building should have sufficient bearing capacity to support the foundation. The micro pile method is used as a method of pile construction to secure bearing capacity for foundation soil.

The micro pile method is a method that uses a micro pile smaller than 300mm in diameter compared to the PHC pile or steel pipe pile method. Therefore, this method can be installed in a narrow place or a limited area, and the foundation pile of tower, chimney, transmission tower and noise control area that simultaneously underpinning, foundation reinforcement, compression and tensile force are applied. It is used for various purposes such as pile construction.

On the other hand, micro piles have a smaller diameter than other piles, so they have excellent resistance to compressive and tensile loads acting in the vertical direction, but have a very weak structural property due to their small horizontal shear surface.

In particular, in the case of the spiral micropile, which does not require an outer casing, the horizontal load must be transmitted only by the diameter of the shaft, so the resistance of the horizontal load is very weak. Nevertheless, spiral piles started in the United States around 1920 and have been used steadily until now due to the convenience of construction, fast construction speed and various applications.

On the other hand, in the case of the micro steel pipe pile, as mentioned above, the diameter is small, so that relaxation occurs after penetration. In particular, the deeper the penetration depth, the greater the relaxation phenomenon. This relaxation occurs to reduce the main surface friction with the ground to act as a cause of weakening the pile support force to reduce the stability of the foundation ground.

Therefore, the present invention was devised in view of the above circumstances, and the grouting layer was formed around the micro-steel pipe pile by enabling the injection and discharging of the filler and allowing the discharged filler to be easily stirred around the pile body. It is to provide a micro-steel pipe pile and its construction method for preventing the occurrence of relaxation after penetration to eliminate the relaxation after penetration, and to further increase the bearing capacity and horizontal resistance of the foundation ground.

According to a suitable embodiment of the micro steel pipe pile for increasing the bearing capacity of the present invention,

At least a plurality of turning screws are formed at predetermined intervals in the lower portion of the lower portion, and a steel pipe pile body having a lower end surface is provided.

One or more filler discharge holes are formed close to the pivot screw and penetrate the steel pipe pile body,

Stirring means for agitating the filler discharged to the filler discharge hole during rotational penetration of the steel pipe pile body is characterized in that located in the vicinity of the filler discharge hole.

Here, the stirring means,

A cone-shaped filler ejection cap which encloses the filler discharge hole and is closed downward and has an opening formed upward to induce a filler upward;

Located between the inner circumferential surface of the filler injection cap and the outer circumferential surface of the steel pipe pile body is characterized in that it is composed of a stirring blade which is installed at regular intervals in the circumferential direction.

At this time, the filling material ejection cap is provided with a plurality of installed from the bottom to the upper side, the upper diameter of the opening is increased as it is installed on the upper side, the maximum diameter is preferably the same or smaller than the diameter of the turning screw.

In addition, the stirring means,

It may be composed of a stirring bit attached to the outer circumferential surface of the steel pipe pile body by varying the height and circumferential position between the adjacent turning screw, respectively.

In addition, the stirring bit may be made in the form of a square block.

In addition, a plurality of stirring bits may be arranged along the spiral direction on the outer circumferential surface of the steel pipe pile body.

The bottom of the steel pipe pile body may also be formed with an acute or conical end.

On the other hand, according to the construction method of the micro steel pipe pile for increasing the bearing capacity of the present invention,

Providing a micro steel pipe pile;

Connecting the upper end of the micro steel pipe pile to the rotary driver to rotate the tube;

Starting the filling of the filling material when the micro steel pipe pile is inserted into the ground to a predetermined depth and discharging the filling material into the filling pipe discharge hole of the steel pipe pile body to the final penetration depth;

In the process of discharging the filler is characterized in that the construction including the step of causing agitation at the same time the filling material discharged by the steel pipe pile body-side stirring means.

According to the micro-steel pipe pile for increasing the bearing capacity according to the present invention, it is possible to inject and discharge the filler into the steel pipe pile body. The discharged filler is easily stirred by the stirring means around the pile body to form a grouting layer.

Therefore, after the penetration of the micro steel pipe pile, a grouting layer is formed around the micro steel pipe pile to eliminate loosening after penetration and to further increase the bearing capacity and horizontal resistance, so that the foundation can be supported more stably. The relaxation problem does not occur.

The following drawings, which are attached in the present specification, illustrate exemplary embodiments of the present invention, and together with the detailed description of the present invention, serve to further understand the technical spirit of the present invention. It should not be construed as limited.
1 is a front view of a micro steel pipe pile according to the first embodiment of the present invention.
Figure 2a is a perspective view of a portion of the lower stirring means is installed in FIG.
Figure 2b is a plan sectional view of the stirring means shown in Figure 2a.
Figure 2c is a perspective view of a portion installed upper stirring means in FIG.
Figure 3 is a construction state of the micro-steel pipe pile according to the first embodiment of the present invention.
4 is a front view of a micro steel pipe pile according to a second embodiment of the present invention.
Figure 5a is an enlarged view of the stirring bit side main portion applied to the second embodiment of the present invention.
FIG. 5B is a sectional view taken along the line XX of FIG. 5A. FIG.
Figure 6 is a construction state of the micro-steel pipe pile according to the first embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the accompanying drawings, but the present invention is not limited thereto.

1 is a front view of a micro steel pipe pile according to a first embodiment of the present invention.

As shown in Figure 1, the micro-steel pipe pile 10 is provided with a steel pipe pile body 12 having a hollow shape in the longitudinal direction. The steel pipe pile body 12 is open at the top and has a filler inlet 10a and the bottom is blocked by the conical end 11. Steel pipe pile body 12 has a plurality of or more turning screws 12a are formed at predetermined intervals from a lower portion to an upper portion in a predetermined section. Therefore, the steel pipe pile 10 is connected to the rotary driver 5 as shown in FIG. 3 and easily rotated into the ground by the turning screw 12a. In this case, the conical end 11 makes the underground penetration of the steel pipe pile body 12 easier. In the present embodiment, the end portion of the steel pipe pile body 12 is configured in a conical shape, but the present invention is not limited thereto, and may be configured as an inclined end that is closed at an acute angle.

One or more filler discharge holes 14 are located close to the turning screw 12a, and the filler discharge holes 14 penetrate the steel pipe pile body 12. In this embodiment, two or three turning screws 12a are formed and two filler discharge holes 14 are provided, but the present invention is not limited to these numbers.

Accordingly, the steel pipe pile body 12 forms one filler injection passage 10b from the filler inlet 10a to the filler discharge hole 14 as shown in FIG. 2 and is required for grouting through the filler inlet 10a. When the filler is injected, the filler is ejected into the filler discharge hole 14 via the filler injection passage 10b.

Micro-steel pipe pile 10 is provided with a stirring means for stirring the filler discharged to the filler discharge hole 14 during rotational penetration of the steel pipe pile body (12).

Stirring means according to one embodiment is shown in Figures 2a to 2c. FIG. 2A shows the stirring means located on the lower side, FIG. 2C shows the stirring means located on the upper side, and FIG. 2B shows a sectional view seen from the B-B line of FIG. 2A. Here, the upper and lower stirring means have the same structure.

Therefore, any one of the stirring means according to an embodiment surrounds the filler discharge hole 14 as shown in Figure 2a and 2b to form an opening (20a) which is closed downward and open upward, filling the filler upwards With a stirring blade 22 which is located between the inner circumferential surface of the filling material spray cap 20 and the outer circumferential surface of the steel pipe pile body 12 to induce the ejection of the cone-shaped filler cap 20 is installed at regular intervals in the circumferential direction Consists of.

At this time, the filling material ejection cap 20 is configured such that the inner diameter of the lower end side is the same as the outer diameter of the steel pipe pile body 12 is joined to the steel pipe pile body 12 by welding, and the upper end inner diameter is smaller than the inner diameter of the lower side. It is largely composed. Therefore, the filler discharged through the filler discharge hole 14 is ejected upward by the filler injection cap 20 when the steel pipe pile is inserted. At the same time, the stirring blade 22 stirs the filler according to the rotational penetration of the steel pipe pile. In addition, the stirring blade 22 also serves to reinforce the cone-shaped structure of the filler injection cap 20.

On the other hand, the stirring means installed on the upper side has the same structure as the stirring means on the lower side as above, but the filler injection cap 20 of the upper side is relatively longer in length and the diameter of the opening 20a is formed larger different. At this time, the maximum diameter of the opening 20a of the filler injection cap 20 installed on the uppermost side is configured to be equal to or smaller than the diameter of the turning screw 12a. This is to avoid disturbing the pivoting penetration of the steel pipe pile body (12).

Therefore, according to the first embodiment, the filler ejected from the filler injection cap 20 located at the lower side when the steel pipe pile is infiltrated first becomes grouting, and the filler injected from the filler injection cap 20 located at the upper side is primary. Secondary grouting is formed around the grouting. This can effectively prevent the occurrence of relaxation of the infiltrated steel pipe pile by forming a grouting layer that gradually increases as the top of the infiltrated steel pipe pile.

It can be configured as shown in Figure 4 to 5b as a stirring means of another embodiment. 4 is a front view of the micro-steel pipe pile according to the second embodiment of the present invention, Figure 5a is an enlarged view of the main portion of the stirring bit side applied to the second embodiment of the present invention, Figure 5b is a line AA of Figure 5a This cross section is shown.

4 to 5b, the stirring bits 120 are protrudingly attached to the outer circumferential surface of the steel pipe pile body 12 by varying their positions in height and circumference between the adjacent turning screws 12a and 12a, respectively. It can be configured as. Stirring bit 120 may be manufactured in the form of a square block, for example. In addition, a plurality of stirring bits 120 may be arranged along the spiral direction on the outer circumferential surface of the steel pipe pile body 12.

Therefore, when the stirring bit 120 is rotated integrally with the steel pipe pile body 12 in the ground, a plurality of stirring bits 120 sweep through the earth and sand surrounding it, the discharge of the filler from the filler discharge hole 14 It is made to rotate and stir the filling material discharged at the same time.

Reference numeral '6' is a 'connecting socket' connected to the rotary driver 5, '2' is a 'socket connecting pin'.

The construction method and operation | movement of the micro steel pipe pile 10 comprised in this way are demonstrated.

First, an injection hose (not shown) for connecting the upper end of the micro steel pipe pile 10 to the rotary driver 5 side socket 6 and injecting a filler necessary for grouting into the steel pipe pile body 12 is connected. . The injection hose is then connected to the micro steel pipe pile 10 via known rotating joint means.

In this state, rotational penetration is carried out by bringing the lower end of the steel pipe pile body 12 to the ground surface at a set position. At this time, the underground penetration of the micro-steel pipe pile 10 is made easy by the turning screw 12a.

In this way, when the underground penetration of the micro-steel pipe pile 10 is made to a certain depth, the filler is injected. The filler may be any filler known in the art for reinforcing soft ground such as cement paste, cement mortar. The injected filler is injected along the filler injection passage 10b of the steel pipe pile body 12 and ejected into the filler discharge hole 14. At this time, the filling material discharge hole 14 is stirred around the filling material is ejected by the rotation of the filler injection cap 20 or the stirring bit 120 integrated with the micro-steel pipe pile 10.

In this way, when the filling material reaches the required depth while continuously injecting the filling material, the rotation driving of the micro steel pipe file 10 is stopped, and the filling material exiting the micro steel pipe file 10 stops from the filling start end. The steel pipe pile body 12 is filled around the height section up to the moment (see FIGS. 3 and 6).

The filler is then condensed to form a grouting layer 30 around the bottom of the micro steel pipe pile 10 to a predetermined height. This grouting layer 30 is bound to the ground to eliminate the occurrence of relaxation of the micro-steel pipe pile 10. In addition, the grouting layer 30 increases the main surface frictional force of the steel pipe pile body 12 to further increase the bearing capacity and the horizontal resistance of the pile.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention . The invention is not limited by these variations and modifications, but is only limited by the scope of the appended claims.

12: steel pipe pile body
12a: turning screw
14: filling material discharge hole
20: Filling blowout cap
22: stirring blade
120: stirring bit

Claims (8)

At least a plurality of turning screws 12a are formed at regular intervals at a lower end portion thereof, and a steel pipe pile body 12 having a lower end surface is provided.
At least one filler discharge hole 14 positioned near the pivot screw 12a and penetrating the steel pipe pile body 12 is formed.
Stirring means for agitating the filler discharged to the filler discharge hole 14 during rotational penetration of the steel pipe pile body 12 is located around the filler discharge hole 14,
The stirring means,
A cone-shaped filler ejection cap 20 which surrounds the filler discharge hole 14 and is closed downward and has an opening 20a formed upward to induce a filler upward;
Consists of a stirring blade 22 which is located between the inner circumferential surface of the filler injection cap 20 and the outer circumferential surface of the steel pipe pile body 12 is installed at regular intervals in the circumferential direction,
The filler blowing cap 20,
Plural number is installed from the lower side to the upper side, and the maximum diameter of the opening is configured to increase as it is installed on the upper side, and the maximum diameter is the same as or smaller than the diameter of the turning screw (12a) for increasing the bearing capacity Micro steel pipe file. delete delete delete delete delete The method of claim 1,
The lower end of the steel pipe pile body (12) is a micro steel pipe pile for increasing the bearing capacity, characterized in that forming an acute or conical end (11). Providing a micro-steel pipe pile (10) as claimed in claim 1;
Connecting the upper end of the micro steel pipe pile (10) to the rotary driver (5) for rotational penetration;
Starting to pressurize the filling material when the micro steel pipe pile 10 is introduced into the ground to a predetermined depth, and discharging the filler material into the filler discharge hole 14 on the steel pipe pile body 12 side to a final penetration depth;
The method of constructing a micro-steel pipe pile for increasing the bearing capacity, comprising the step of simultaneously causing agitation to the filler discharged by the steel pipe pile body 12 side stirring means during the discharge process of the filler.

Images