KR20100123576A - Method for carrying out improved pile - Google Patents

Abstract

PURPOSE: An installation method of improved micro piles, an improved micro pile structure, and a pipe having an uneven cross-section for an improved micro pile structure are provided to improve the structural rigidity of the pile structure because the outer protrusions of the pipe enhance the anchoring force. CONSTITUTION: An installation method of improved micro piles is as follows. The ground is drilled and a casing is installed in the bore. A pipe(30) having an uneven cross-section is inserted in the casing. A pile(40) is inserted in the pipe and grouted. The casing is pulled out. A bracket(60) is installed on the top of the pile and foundation concrete(70) is placed.

Description

Improved pile construction method {METHOD FOR CARRYING OUT IMPROVED PILE}

The present invention relates to a method for constructing pile foundations, and more particularly, to an improved pile construction method for drilling a ground to a predetermined depth to form a cast-in-place pile with grouting.

The bearing capacity of the foundation ground is determined by the strength of the foundation, the size of the foundation, and the incorporation of the foundation. However, if the load transmitted to the foundation is very large, the indentation of the foundation must be considerably increased, so the entire foundation must be deeply indented, which leads to an increase in construction cost.

Therefore, in this case, by using the pile method to penetrate deep into the ground, such as steel, concrete, wood with a large rigidity so that the foundation is supported in a solid deep layer. The pile method should be easy to penetrate in the middle soils and ensure the bearing capacity of the pile tip.

However, in areas such as river basins, it is impossible to access the piles due to hitting and scouring occurs, so use the pile pile method to drill the concrete in advance after using the auger equipment.

One of the pile pile methods is a micro pile method for soft ground. A micro pile is a small drilling machine, which drills to a predetermined depth in the ground, assembles and installs piles and rebars, and grouts at low pressure (7 to 20 BAR) using a pump. Means small-caliber cast-in-place piles to be carried out and installed.

In the construction method using the micro pile, the bearing capacity by the main surface friction is increased than the general pile, and the frictional resistance effect of the surroundings is larger than the actual drilling diameter. In addition, there is a definite support effect on the distal end will also increase the bearing capacity.

Due to such characteristics, the micro pile is installed on sandy soils with greater frictional resistance than viscous soils. By using small sized drilling equipment, vibration and noise can be reduced compared to type construction or large diameter drilled piles, so it is highly utilized as a foundation pile in a downtown area or a foundation pile in a factory area, and construction in a soft ground is easy.

1A to 1C illustrate a micro pile construction method according to the prior art. As shown, the micro pile construction method is carried out by (1) preparatory work and drill drilling and casing insertion, (2) assembly and insertion of the micro pile, (3) grouting and upper fixing and the foundation concrete curing.

However, the conventional site pile method has the following problems.

Field pile methods, including micro pile method, show a relatively large amount of settlement compared to pile size (section area), and the foundation ground is relaxed, which greatly reduces friction around piles.

If the friction around the pile is reduced, there is a problem that the ground support capacity is insufficient to be unable to use the strength of the pile body enough to be uneconomical.

In addition, since the micro pile, which is one of the pile pile methods, is a method performed in order to reinforce the bearing capacity for the upper load of the soft ground, it is perforated with a crawler drill to prevent the buried layer or the soft layer hollow wall from falling down. After that, the casing should be installed until the rock bed. If the hollow wall collapses before the pile is inserted, the pile can not be inserted and the casing is inevitable to prevent the collapse of the hollow wall because there is no space to grout after inserting the pile.

When grouting by inserting a pile into the casing, grouting can be performed while drawing the casing. However, in the case of drawing the casing at the same time as grouting, the void wall is gradually collapsed and the pile section cannot be formed so that the predetermined section cannot be secured.

Therefore, in the prior art, there is a problem in that the casing for constructing the micro pile is buried as it is, so that the relatively expensive casing cannot be reused.

The present invention is to solve such a conventional problem, the object of the present invention is to increase the friction force around the pile.

Another object of the present invention is to reuse the casing used for pile construction.

According to a feature of the present invention for achieving the above object, the improved pile construction method of the present invention comprises a drilling and casing installation step of drilling the ground to install the casing; An uneven end pipe insertion step of inserting an uneven end pipe into the casing; A file insertion step of inserting a file into the uneven section pipe; A grouting construction step of grouting the pile; Casing drawing step of drawing the casing after the grouting construction; And it is preferable to include a base concrete forming step of installing a bracket on the top of the pile and cast the foundation concrete.

The grouting construction step of the present invention preferably includes a grouting compaction step of compacting the grouting by generating a vibration by the vibration generating unit provided in the uneven end pipe.

Casing drawing step of the present invention preferably comprises a casing drawing assistance step to assist the drawing of the casing by generating a vibration by the vibration generating portion provided in the uneven end pipe.

The basic concrete forming step of the present invention preferably includes a precast panel installation step of installing a precast panel on the upper surface of the ground before installing the bracket.

Forming the foundation concrete of the present invention preferably comprises the step of connecting the reinforcing bars provided in the bracket and the reinforcing bar forming the skeleton of the foundation concrete, and after the foundation concrete is poured.

An improved pile construction method according to another embodiment of the present invention comprises a drilling step of injecting cement paste into a hole to be drilled while drilling the ground using an auger; When the drilling is completed by the auger stirring the auger wall and cement paste by repeatedly moving the auger up and down; Drawing the auger and injecting cement paste into the perforated holes simultaneously with drawing the auger; Inserting step of inserting a file having a concave-convex cross-section tube in the perforated hole; And it is preferred to include a fixing step of pressing or hitting the inserted file fixed.

The drawing step of the present invention preferably comprises the step of injecting a cement paste for the tip portion to be poured in the tip portion of the pile.

Inserting step of the present invention preferably comprises the step of compacting the cement paste by generating a vibration by the vibration generating portion provided in the uneven end pipe.

The fixing step of the present invention preferably includes a base concrete forming step of installing the bracket on the top of the pile and placing the foundation concrete.

It is preferable that the improved pile structure of this invention is constructed by the said construction method.

Concave-convex cross-section tube of the present invention is a concave-convex cross-section tube body is inserted therein; It is preferable to include a plurality of protrusion layers provided on the outer circumferential surface of the uneven section pipe body.

The protrusion layer of the present invention preferably includes a vibration generating portion for generating vibration.

According to the improved pile construction method according to the present invention, by using the uneven cross-section tube is reduced the frictional frictional force to facilitate the drawing of the casing and the casing can be reused by preventing the collapse of the empty wall when the casing is drawn out, thereby reducing the construction cost It has the advantage of saving resources, and in addition to perforation by auger, cement paste can be injected to prevent the collapse of the empty wall, and cement paste can be injected even when the pile is inserted to improve the frictional force around the pile. Due to the protruding layer formed on the outer surface, the frictional force with the buried layer is improved to improve the structural rigidity of the pile.

Hereinafter, with reference to the accompanying drawings a preferred embodiment of the improved pile construction method according to the present invention will be described in more detail.

2 to 8 show a preferred embodiment of the improved pile construction method according to the present invention.

As shown, first, the auger 10 is used to form a hole for constructing a pile. The hole for constructing the pile is preferably formed through the buried layer (soft layer) 13 composed of soil formed from the ground to the rock layer (support layer) 15 below the buried layer 13.

When a hole is formed by the auger 10, the casing 20 is inserted into the hole. The casing 20 serves to prevent the buried layer 13 from being collapsed or buried when the pile is inserted into a hole formed in the ground. The casing 20 is preferably inserted only in the buried layer (13).

When the casing 20 is inserted into the hole, the uneven end pipe 30 is inserted into the casing 20, as shown in FIG. The uneven section tube 30 serves to improve the frictional force with the buried layer 13 and to facilitate the drawing of the casing 20. The uneven section pipe 30 may be configured such as PE pipe.

A plurality of protrusion layers 33 are formed on the outer surface of the uneven end pipe main body 31 forming the outer shape of the uneven end pipe 30. The protrusion layer 33 serves to reduce the contact area with the inner circumferential surface of the casing 20 and to increase the frictional force with the buried layer 13.

In addition, the protrusion layer 33 is provided with a vibration generator 35 for generating vibration. The vibration generating unit 35 is configured as a vibrator (Vibrator) that is operated in a wired or wireless manner to generate a vibration in the concave-convex cross-section 30 to compact the grouting or to facilitate the drawing of the casing. do.

When the uneven section tube 30 is inserted into the casing 20, the pile 40 is inserted into the uneven section tube 30 as shown in FIG. 4. The pile 40 is preferably inserted into the rock layer 15 past the buried layer 13.

When the pile 40 is inserted into the uneven end pipe 30, grouting is performed between the file 40 and the uneven end pipe 30, as shown in FIG. The grouting is to fill between the pile 40 and the concave-convex cross-section tube 30 and the pile 40 and the concave-convex cross-section tube 30 are integrated by grouting.

In addition, the grouting compaction operation may be performed by generating vibration by the vibration generator 35 provided in the uneven end pipe 30 during the grouting construction. By such grouting compaction work, the construction density of grouting can be improved.

When the grouting construction is completed, the work to draw the casing 20 is performed. When the casing 20 is pulled out, the protrusion layer 33 formed on the outer surface of the uneven end pipe 30 reduces the contact area between the uneven end pipe 30 and the casing 20, so that the casing is easily drawn out.

In addition, by generating a vibration by the vibration generating portion 35 provided in the uneven end pipe 30 so that the outer surface of the uneven end pipe 30 is easily separated from the inner surface of the casing 20, the casing 20 Can be easily pulled out.

When the drawing of the casing 20 is completed, the precast panel 50 is installed on the upper surface of the buried layer 13, and the bracket 60 is installed on the upper end of the pile 40. The bracket 60 is a component for transferring an upper load to the pile 40.

The bracket 60 is provided with a seating plate 61 seated on an upper surface of the precast panel 50 and spaced apart at predetermined intervals from the upper surface of the seating plate 61, as shown in FIG. A wing plate 65 including a 63 and a head fixing portion 67 connected to an upper end of the wing plate 65 and fixing an upper end of the pile 40.

When the bracket 60 is fixed to the upper end of the pile 40, the reinforcing bar 63 of the bracket 60 is connected to the reinforcing bars forming the skeleton of the foundation concrete 70, and the foundation concrete 70 Pour. Since the bracket 60 is connected to the reinforcing bar of the foundation concrete 70 and cured integrally with the foundation concrete 70, the connection rigidity of the foundation concrete 70 and the pile 40 may be improved.

In the improved pile construction method of the present invention, a method of constructing the pile 40 while protecting the void wall by injecting cement paste without using the casing 20 is illustrated in FIGS. 9 to 14.

As shown, first, an auger 10 is used to form a hole for constructing a pile. At this time, the auger 10 is drilled while injecting cement paste while drilling. When the cement paste is injected together with the perforations for inserting the pile 40, the cement paste may be agitated with the surrounding void walls by the auger 10 to form a blocking film, thereby preventing collapse of the void walls.

The cement paste may be composed by mixing cement, water or bentonite. The mixing ratio of the cement paste is shown in Table 1 below.

Kinds Mixing amount during excavation Tip mixing amount cement 120 kg 400-800 kg water 450ℓ 450ℓ Bentonite 25 kg

The tip mixing amount described in Table 1 means a separate mixing amount for placing the pile 40 in the hole formed by the auger 10 to secure the tip bearing force by placing the pile 40 at the tip of the pile 40. The cement paste to be poured at the tip of the pile 40 is preferably poured to a position of 500 mm or more from the tip of the pile 40.

When the auger 10 is excavated using the auger 10, it is often checked whether the auger 10 reaches the rock layer (support layer) 15. When it is confirmed that the auger 10 has reached the rock layer 15, the auger 10 continuously injects cement paste while drilling to the final depth to be drilled, that is, the design depth.

When the auger 10 reaches the design depth, the auger 10 is reciprocated up and down so that the raw soil and the cement paste are stirred. Due to this, the ground soil and the cement paste of the hollow walls can be stirred more densely.

When the stirring operation by the auger 10 is completed, the auger 10 is drawn out. At this time, the auger 10 is drawn while injecting cement paste into the perforated holes. Then, the pile 40 is inserted into the hole formed by the auger 10 using its own weight.

On the outer surface of the pile 40, the above-mentioned concave-convex cross section tube 30 may be mounted. Between the uneven end pipe 30 and the pile 40 can be integrated by applying a separate adhesive.

When the pile 40 is inserted into the hole, vibration is generated by using the vibration generating unit 35 of the uneven end tube 30 mounted on the outer circumferential surface of the file. Compacting the cement paste is located can improve the adhesion with the uneven end pipe (30).

When the pile 40 is inserted into the hole due to its own weight, the pile 40 is positioned to the design depth by the press-fitting or striking method. Then, the cement paste is filled between the existing empty wall and the pile 40 in which the cement paste is stirred, thereby improving the friction force around the pile 40, and the friction force is increased by the uneven end pipe 30 installed on the outer surface of the pile 40. By further improving, the file construction can be improved.

The bracket 60 mentioned above may be installed at an upper end of the pile 40 to form a foundation structure by the precast panel 50 and the foundation concrete 70.

15 shows a construction state to reinforce the slope using the file of the present invention.

As shown in the drawing, the pile according to the present invention can be installed on the slope and the precast concrete panel is installed on the head of the pile to prevent the slope from being collapsed. Such rock slopes are more economical than the general retaining wall method due to the reduction of soil volume, and the construction cost is reduced compared to the precast retaining wall because the panel size is large.

The file construction method mentioned above can be applied to a micro pile.

In the scope of the basic technical spirit of the present invention, many modifications are possible to those skilled in the art, and the scope of the present invention should be interpreted based on the claims which will be described later. .

According to the improved pile construction method according to the present invention as described above in detail has the following advantages.

By using the uneven section pipe, the casing can be easily drawn out, and the casing can be reused by preventing the collapsing of the wall when the casing is drawn, thereby reducing the construction cost and saving resources.

Perforation by auger at the same time to inject cement paste to prevent the collapse of the empty wall, and also to insert the cement paste when the pile is inserted to improve the frictional force around the pile, the buried layer due to the protrusion layer formed on the outer surface of the uneven section pipe There is an advantage of improving the ease of construction by improving the frictional force and the structural rigidity of the pile.

In addition, there is an advantage that the slope can be reinforced construction of the incision and landfill as well as the ground.

1a to 1c is a construction sequence diagram showing a pile construction method according to the prior art.

Figure 2 is a cross-sectional view showing the step of installing the perforation and casing of the improved pile construction method according to the present invention.

Figure 3 is a construction sectional view showing the step of installing the uneven section pipe of the improved pile construction method according to the present invention.

Figure 4 is a construction cross-sectional view showing the step of installing the file of the improved pile construction method according to the present invention.

Figure 5 is a construction cross-sectional view showing the steps of constructing the grouting of the improved pile construction method according to the present invention.

Figure 6 is a construction cross-sectional view showing a step of drawing the casing of the improved pile construction method according to the present invention.

7 is a cross-sectional view showing the step of installing the bracket and precast concrete panel of the improved pile construction method according to the present invention.

8 is a cross-sectional view showing the step of installing the basic concrete of the improved pile construction method according to the present invention.

9 is a construction cross-sectional view showing a step of drilling using another embodiment of the improved pile construction method according to the present invention.

10 is a cross-sectional view showing a step of drilling to the design depth using another embodiment of the improved pile construction method according to the present invention.

11 is a cross-sectional view showing a step of stirring the cement paste and the hollow wall using another embodiment of the improved pile construction method according to the present invention.

12 is a cross-sectional view showing the step of drawing the auger using another embodiment of the improved pile construction method according to the present invention.

Figure 13 is a construction cross-sectional view showing the step of inserting the file using another embodiment of the improved pile construction method according to the present invention.

14 is a cross-sectional view showing the step of pressing or hitting the pile using another embodiment of the improved pile construction method according to the present invention.

Figure 15 is a construction cross-sectional view showing a state in which the pile on the slope using the improved pile construction method according to the present invention.

Description of the Related Art [0002]

20: casing 30: uneven section pipe

33: projection layer 35: vibration generating unit

40: File 50: Precast Concrete Panel

60: bracket 70: foundation concrete

Claims (12)

Drilling and casing installation step of drilling the ground to install the casing; An uneven end pipe insertion step of inserting an uneven end pipe into the casing; A file insertion step of inserting a file into the uneven section pipe; A grouting construction step of grouting the pile; Casing drawing step of drawing the casing after the grouting construction; And Installing a bracket on the top of the pile and includes a foundation concrete forming step of pouring the foundation concrete Improved pile construction method. The method of claim 1, The grouting construction step It includes a grouting compacting step of compacting the grouting by generating a vibration by the vibration generating unit provided in the uneven section pipe Improved pile construction method. The method of claim 1, The casing drawing step is And a casing drawing assisting step of assisting drawing of the casing by generating vibration by a vibration generating unit provided in the uneven end pipe. Improved pile construction method. The method of claim 1, The basic concrete forming step And a precast panel installation step of installing a precast panel on an upper surface of the ground before installing the bracket. Improved pile construction method. The method of claim 1, The basic concrete forming step And connecting the reinforcing bars provided in the bracket with the reinforcing bars forming the skeleton of the foundation concrete, and pouring the foundation concrete and curing the foundation. Improved pile construction method. A drilling step of injecting cement paste into a hole to be drilled while drilling the ground using an auger; When the drilling is completed by the auger stirring the auger wall and cement paste by repeatedly moving the auger up and down; Drawing the auger and injecting cement paste into the perforated holes simultaneously with drawing the auger; Inserting step of inserting the file having a concave-convex cross-section tube in the drilled hole; And And a fixing step of pressing or hitting the inserted file to fix the inserted file. Improved pile construction method. The method of claim 6, The drawing step is Injecting a cement paste for the tip portion, which is poured at the tip of the pile; Improved pile construction method. The method of claim 6, The insertion step Comprising the cement paste by generating a vibration by the vibration generating portion provided in the uneven end pipe Improved pile construction method. The method of claim 6, The fixing step Installing a bracket on the top of the pile and includes a foundation concrete forming step of pouring the foundation concrete Improved pile construction method. An improved pile structure constructed by the construction method according to any one of claims 1 to 9. In the uneven section pipe used in the construction method according to any one of claims 1 to 9, Uneven end pipe body is inserted into the file; It includes a plurality of projection layers provided on the outer circumferential surface of the uneven section tube body Uneven section pipe of improved pile structure. The method of claim 11, The protrusion layer Vibration generating portion for generating a vibration Uneven section pipe of improved pile structure.

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