KR20060024826A - Working method of pile with an extended head - Google Patents

Abstract

The present invention relates to a construction method of the head extension type for supporting the load of the structure, for the construction of the head extension pile to increase the end bearing capacity of the pile by having a reinforcement having a diameter larger than the diameter of the pile to the embedded end of the pile Preliminary work for selecting piles, preparing and checking driving, handling obstacles, preparing work for checking the ground and reinforcing the ground after reinforcing the ground, and checking the verticality of the screw auger and leader from the front and side. Screw auger position fixing step; An excavation step of the screw auger to idle the auger to remove the slime; Injecting cement paste at high pressure; Setting the head extension pile to be vertical and intruding into self weight; In order to penetrate the head extension pile after the pile embedding process, the construction can be provided in a staggered step order, thereby providing a construction method that can secure stability, constructability, and economics against pile strength.

Pile, Driving, Pile Cap, Screw Auger, Reader, Cement Paste, Pile Penetration, Casing Drawing

Description

Working Method of Pile with an Extended Head}

1 is a conceptual diagram showing the file history showing the relationship between the internal strength of the pile and the construction history of the constructed pile;

2 is a cross-sectional view showing the structure of a reinforcing pile having a reinforcing portion at one end;

3 is a cross-sectional view showing the structure of a pile having reinforcing portions at both ends of the pile;

Figure 4 is a cross-sectional view showing the structure of the reinforcement pile coupled to the reinforcement plate on one end of the existing pile (PHC),

5 is a cross-sectional view of the reinforcement pile having a reinforcement blade plate for supporting the protrusion of the reinforcement plate of FIG. 4;

6 is a view showing a central through hole formed in the reinforcing plate used in the construction method of the present invention,

7 is a block diagram showing a construction method of a head extension pile using a casing in accordance with the construction method of the present invention in the soil collapsed during drilling;

8 is a block diagram showing the construction method of the head-extended pile of the present invention in soil that does not collapse during drilling;

9 is a view showing a process completed according to the construction method of the head-extended pile of the present invention in soil that does not collapse during drilling.

-Explanation of symbols for the main parts of the drawing-

2: head expandable pile 11: structure

12: cylindrical pile portion 20: lower reinforcement portion

21: lower reinforcement 22: lower cone

30: upper reinforcement portion 31: upper reinforcement

32: upper cone 40: reinforcement plate

41: steel plate reinforcing band 50: reinforcing blade plate

52: center hole 54: hollow part

62: screw auger 66: cement paste

The present invention relates to a construction method of the head extension pile, and more particularly, to the pile strength of the pile to improve the bearing capacity of the pile supporting the load of the structure as a pile supporting the load of the structure, construction and economic efficiency It relates to a construction method for providing a pile construction method that can secure the.

In general, when a building or a structure is erected, a foundation work is performed to reinforce the ground to support the upper structure according to the condition of the ground or the load of the structure. A shallow foundation or a deep foundation is performed according to various conditions such as the load of the structure. The case where the root entrance width ratio is 1 or less is called the shallow foundation, and the case where the root entrance width ratio is 1 or more is defined as the deep foundation. In the case of a shallow foundation, the structure is directly supported on the ground without using piles, and when the ground below the structure cannot support the load of the upper structure, piles are used to reinforce the bearing capacity of the ground.

The pile foundation is a foundation method that connects the head to the structure. If the pile is classified according to the material, it can be classified into steel pile, concrete pile, composite pile, etc. It can be divided into pour method.

Type construction method is to force the pile into the ground by striking the pile from the top after the pile is put up. When the pile is pushed into the ground by force of the driving energy, the pile shaft is pushed into close contact with the soil so that the external bearing capacity of the pile is increased. Good and easy to install.

However, the type method is difficult to vertically approach when the pile is to be installed deeply, excessive vibration and noise are generated, and construction in the city is limited.

On the other hand, the embedding method solves various problems of the type construction method by forming a hole in the ground in advance, injecting an adhesive about half of the hole, and then inserting and fixing the file into the hole. As a result, the embedding method is mainly used for the pile foundation in the city center now.

In the construction work, the basic construction occupies a very large portion, and in the case of pile construction, various pile construction methods are used for reasons such as different ground conditions and conditions for each site, lack of accurate understanding of driving equipment and construction based on the experience of the contractor. I am having difficulty every time.

1 is a conceptual diagram of the file strength showing the relationship between the internal strength of the pile and the construction history of the constructed pile. As shown in FIG. 1, the load PF of the structure 11 is supported by the construction strength of a plurality of piles 12 adjoining the bottom of the structure 11. The construction strength of the pile 12 indented is the sum of the tip bearing force TP of the pile tip and the peripheral frictional force SF of the pile side. By the way, the strength of the pile itself is high, but the construction strength of the pile is lowered due to workability.

For example, in the case of a high strength concrete pile (PHC, hereinafter referred to as PHC) of φ400, the pile itself has a internal strength of 112 tf, but the construction strength is about 60 to 80 tf, resulting in a waste of 32 to 52 tf of pile strength. In particular, in the case of the embedding method, after the ground is drilled larger than the diameter of the pile, the fabricated pile is installed in the perforation and the cement is injected between the pile and the ground to increase the peripheral frictional force. Subsequent tests showed that the peripheral friction was very minimal and most construction strength was dependent on the tip bearing capacity. Therefore, in the embedding method, it was necessary to make the construction history close to the pile itself, thereby improving the use efficiency of the pile.

Japanese Patent Application Laid-Open Publication No. 55-50142 has been disclosed as a conventionally known technique. A tip supporting steel pipe pile is formed by attaching a tip steel sheet having a through hole to the tip of a steel pipe and forming a reinforcing rib between the steel pipe and the tip steel sheet. Is described.

 The known technology is composed of a method of inserting a pile into an exposed ground or an excavated hole and then simply seating it on the ground, but not having an economic ripple effect, and filling the soil without injecting cement. Because of this, there is a defect that the waste capacity is large, and the reinforcing difficulty (central reinforcement) is very difficult and excessively expensive.

On the other hand, Japanese Laid-Open Patent Publication No. 2003-138561 is known as a similar technique, but this discloses a multi-stage expansion term (blocking wall) proposed to improve the continuous underground wall. In the literature, there is a problem that the construction difficulty is large and the cost is excessively consumed as a general concrete site placing method using a longitudinal continuous excavation equipment directly in the field. And the multi-level expansion port (blocking wall) in the form of a continuous underground wall is a technique that is not used in reality because of the form of excavation, because the concrete curing car and reinforcing bar must be used in combination.

The present invention is to solve the problems of the prior art made as described above,

An object of the present invention is to increase the construction strength of the pile without affecting the weight or volume of the pile used in the embedding method, pile strength during the construction of the pile to support the load of the structure to increase the use efficiency and economic efficiency of the pile To provide a construction method of the head extension pile that can secure the stability, construction and economics.

Another object is to provide a method of constructing a head extension pile which can be applied to the embedding method as it is and at the same time increase the construction strength of the pile by driving after the embedding method.

The head extension pile used in the construction method of the present invention uses a pile formed by attaching a reinforcement larger than the diameter of the pile to a predetermined thickness or integrally formed at the tip of the pile to increase the bearing capacity of the pile. It may be formed only at one end and may be formed at both ends of the pile.

The construction method of the present invention for achieving the above object is the selection of piles and the preparation and confirmation of the driving, the preparation work step such as obstacle handling, the step of preparing the driving installation after confirmation of the working ground and reinforcement of the ground, front and side A screw auger position fixing step of preparing a screw auger and a leader to confirm the verticality;

Excavation step by screw auger to remove the slime by idling the auger while spraying high pressure air in place after confirming the completion of drilling to the top of the soil layer possible to be beaten;

    Next, the step of mixing the cement paste in the order of water, cement using a dedicated mixer to inject the cement paste at a high pressure while drawing the screw auger;

Injecting the cement paste after the injection of the cement paste and optionally reintroducing the screw auger for mixing and slime treatment; After such pile embedding process, it can be achieved by installing in the order of hitting in order to penetrate the head extension pile.

In addition, the preparation step includes a casing installation step after the step installation step, and the casing drawing step is included before the pile beating step to prevent the collapse of the empty wall when the top of the weathering zone, which is the ground of the site collapses, After the drilling to the upper end to the support layer is characterized in that consisting of the step of performing a rear helm.

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

First, the head extension file applied to the construction method of the present invention will be described.

2 is a cross-sectional view showing the structure of a reinforcing pile having a reinforcing portion at one end. As shown in FIG. 2, the head extension pile 2 is composed of a cylindrical pile portion 12 and a lower reinforcement portion 20, and the lower reinforcement portion 20 has a lower reinforcement portion 21 and a lower cone plate 22. It consists of.

And the upper part has a driving surface (c) after being driven after the pile embedded construction, the cylindrical pile portion 12 is a concrete pile, PHC, steel pipe, H-shaped steel having a diameter of 350, 400, 450, 500, 600 mm, etc. Other composite pipes and wooden pipes.

The lower reinforcement 21 is a plate-shaped structure having a predetermined thickness that is integrally formed with the cylindrical pile portion 12 or joined by the joining means at the lower end of the cylindrical pile portion 12. The lower cone 22 is formed with an inclined portion having a constant inclination angle between the cylindrical pile portion 12 and the outer peripheral side of the lower reinforcing rod 21.

Table 1 illustrates the dimensions and dynamics of the pile.

TABLE 1

Type of file Φ350 PHC Φ400 PHC Φ450 PHC Φ500 PHC File itself history (tf) 89 112 137 173 Peripheral frictional force (tf) 30.37 38.13 46.76 59.04 Tip bearing capacity (tf) 58.63 73.87 90.24 113.96 Diameter of existing pile (mm) 350 400 450 500 Existing pile cross section (㎠) 961.625 1256 1590 1963 Reinforcement part proper diameter (mm) 473 531 587 660 Reinforcement section cross section (㎠) 1759 2216 2707 3419

In the case of Φ 350 PHC in Table 1, the tip bearing capacity must be 58 tf to obtain the pile capacity of 89 tf. By the way, by the cross-sectional area 961.625 cm 2 of the existing pile having a diameter of 350 mm, it is not possible to obtain a tip support force of 58 tf. Therefore, in order to obtain the tip bearing force 58 tf, the cross section of the tip of the pile must be 1759 cm 2. That is, the diameter of the reinforcement portion needs to be extended to 473 mm.

In Table 1, in the case of Φ400, Φ450, and Φ500 PHC, the cross-sectional area of the tip end should be extended to 2216, 2707, 3419 ㎠, respectively, in order to utilize all pile strengths corresponding to the diameter of each pile. The diameter needs to be extended to 531, 587, 660 mm.

On the other hand, it is preferable that the diameter (D) and thickness (T) of the lower reinforcing rod 21 has the same size, the ratio of the inclination ratio of the cone 22 is a ratio of the protrusion width (a) and the inclination width (b) of 1: 1 It selects in the range of -10, Preferably makes ratio of protrusion part width a and inclination part width b 1: 6.

3 is a cross-sectional view showing the structure of a pile having reinforcing portions at both ends of the pile. As shown in FIG. 3, both reinforcement piles have a lower reinforcement portion 20 formed at the lower end of the cylindrical pile portion 12 and an upper reinforcement portion 30 formed at the upper end portion of the cylindrical pile portion 12. It is composed of The upper reinforcement part 30 is composed of an upper reinforcement 31 and an upper cone 32 like the lower reinforcement 20 of FIG. 2. In addition, the upper reinforcement portion 30 has the same shape and dimensions as the structure of the lower reinforcement portion 20.

Figure 4 is a cross-sectional view showing the structure of the reinforcement pile coupled to the reinforcing plate at one end of the existing pile (PHC). As shown in FIG. 4, the reinforcement pile is composed of a cylindrical pile portion 12 and a reinforcement plate 40.

And the upper portion of the cylindrical pile portion 12 has a driving surface (c) after being driven after the pile embedded, the cylindrical pile portion 12 has a concrete pile, PHC having a diameter of 350, 400, 450, 500 mm, etc. , Steel pipes, and the like, and the reinforcement plate 40 uses an iron plate.

The reinforcement plate 40 is a plate-shaped structure having a predetermined thickness coupled to the lower end of the cylindrical pile portion 12 by the cylindrical pile portion 12 and the joining means. Here, the joining means may join the pile and the reinforcement plate by general welding when the cylindrical pile part 12 is a steel pipe. On the other hand, when the pile is a concrete pile, PHC, etc. is further provided with a steel plate reinforcing band 41 surrounding the lower end of the pile, the steel plate reinforcing band 41 and the reinforcing plate 40 to combine the pile and the reinforcing plate.

Table 2 illustrates the dimensions and dynamics of piles and stiffeners.

TABLE 2

Type of file Φ350 PHC Φ400 PHC Φ450 PHC Φ500 PHC File itself history (tf) 89 112 137 173 Peripheral frictional force (tf) 30.37 38.13 46.76 59.04 Tip bearing capacity (tf) 58.63 73.87 90.24 113.96 Diameter of existing pile (mm) 350 400 450 500 Existing pile cross section (㎠) 961.625 1256 1590 1963 Reinforcement Plate Proper Diameter (mm) 473 531 587 660 Reinforcement plate cross section (㎠) 1759 2216 2707 3419 Gusset plate diameter (mm) 123 131 137 160 Compressive stress (σc: tf / ㎠) 0.10 0.10 0.10 0.10 Thickness of Reinforcement Plate (mm) 10.8 11.1 11.3 12.2 Extrusion Length of Reinforcement Plate (a: mm) 62 66 69 80

Here, sigma c = 3 x tip bearing force / reinforcing plate cross section.

In the case of Φ350 PHC in Table 2, the tip bearing capacity is 58 tf to obtain 89 tf pile internal strength.The tip bearing capacity of 58 tf is obtained by the cross section 961.625 ㎠ of the existing pile with a diameter of 350 mm. Can't get it. Therefore, the cross-sectional area of the tip of the pile must be widened to obtain 58 tf of tip bearing capacity. In Table 2, the cross-sectional area of the reinforcing plate is 1759 cm 2 and the diameter is 473 mm, and the thickness t of the reinforcing plate is selected to be 10.8 mm.

In Table 2, in the case of Φ400, Φ450, and Φ500 PHC, the cross-sectional area of the reinforcement plate is extended to 2216, 2707, 3419 cm2, respectively, in order to utilize all pile strengths corresponding to the diameter of each pile. The diameters are expanded to 531, 587 and 660 mm. As can be seen from Table 2, the thickness of the reinforcement plate is formed thicker as the protrusion length of the reinforcement plate is larger.

FIG. 5 is a cross-sectional view of the reinforcement pile provided with a reinforcement blade plate for supporting the protruding portion of the reinforcement plate of FIG. As shown in FIG. 5, when the protruding length of the reinforcing plate 40 extending outward from the side of the cylindrical pile part 12 is long, or the thickness t of the reinforcing plate 40 is small, the reinforcing plate 40 is provided. The outer circumferential edge of) may be bent upward.

At this time, the effective cross-sectional area of the reinforcing plate 40 is reduced to reduce the tip bearing force. In order to prevent this, a plurality of reinforcing blade plate 50 is provided between the reinforcing plate 40 and the cylindrical pile portion 12.

The reinforcing blade plate 50 is installed on the upper surface of the reinforcing plate 40, the triangular iron plate around the cylindrical pile portion 12 at regular intervals. Since the reinforcement wing plate 50 and the reinforcement plate 40 all use iron plates, etc., it can be combined by general welding.

In the case of a pile such as PHC, the reinforcement wing plate 50 and the cylindrical pile part 12 join the steel plate reinforcing band 41 and the reinforcement wing plate 50 surrounding the lower end of the cylindrical pile part 12 by welding or the like. In the case of a steel pipe pile, the reinforcing blade plate 50 is directly joined to the side of the steel pipe pile by welding or the like.

5 shows the shape and coupling relationship of the reinforcement wing plate 50.

In addition, the reinforcing plate 40 is formed by drilling a central through-hole 52 in the center, thereby preventing the head-extension pile 2 from rising by underground leachate, which is introduced into the hollow portion 54 and is filled. have.

The central through hole 52 also introduces unnecessary slime into the pile during penetration of the pile, and also serves to introduce the cement paste into the pile, whereby the slime and cement paste are mixed and cured.

As described above, the file used in the construction method of the present invention uses the file shown in FIGS. 6 to 6, and as the head extension type file, a casing is used when drilling the ground when the site has a soil layer in which the upper part of the weathering zone collapses. Therefore, it is applied to the site to prevent the collapse of the wall and to carry out the rear navigating up to the support layer after the perforation to the top of the swivelable ground stratum of the helm.

In the case of soil collapse in this way, the head expansion pile (2) suitable for the load capacity is selected, and in the case of PHC pile, the closed type shoe (shoe) is used at the tip, and in the strata where the groundwater level is high, Center hole 52 in the middle to prevent the injuries to the pile water level when the head-expanded pile (2) penetration by self-weight.

And check the rudder 58 and equipment according to the ground and check whether there is no abnormality, and after estimating the depth of drilling, the dimensions on the pile every 50cm from the top of the weathering table, and every 20cm near the support layer.

At this time, the top of weathering zone is based on N value 50/20 ~ 10, and the estimation of the top of weathering zone is based on geological survey, RPM of the machine, and discharged soil.

The diameter of the casing is based on 20mm ~ 50mm of the diameter of the head extension pile (2), and the safety of driving is largely affected by the construction of the pile, which affects the verticality and the driving of the pile. It may cause a safety accident during construction.

In addition, the mixing ratio should be water: cement = 1: 1, and the cement should be mixed about 40kg per 1M, and because of the high pressure feeding, the equipments such as the mixer plant, the mixing weighing device, and the compressor, which are not shown, are concentrated in one place. Manage and identify and remove obstacles on the ground or underground.

A detailed description will be given below with reference to FIG. 7.

7 is a block diagram showing a construction method of a head extension pile using a casing in accordance with the construction method of the present invention in soil collapsed during drilling.

First, as described above, the preparation of the file, the preparation and confirmation of the driving, the preparation of the obstacle, etc. are performed.

Therefore, when installing rides, if the grounds are fragile, if the rides may be inclined or moved during operation, install the rides after confirming the ground and reinforcing the grounds, such as laying a double hole or laying rubble to keep the ground reinforced. (Step S20).

In the next step (S30) to fix the position of the casing is installed vertically and the excavation step (S40) is performed while paying attention to the following matters.

That is, in order to protect the wall and prevent the blockage of the ejection port, the screw auger is introduced into the casing, the screw auger is excavated in a forward rotation, the casing is reversely rotated, and the screw auger is pre-drilled compared to the casing. (SLIME) is discharged by high pressure air installed at the tip of screw auger.

The depth of the casing is applied to the soil layer where the wall does not collapse, and it is excavated to N value 50/20 ~ 10. (Weather degree)

According to the geological survey, it is possible not only to identify the possible soil strata in the site, but also to prepare the strata section of the geological survey vertically and horizontally to compare the geological section and the result of the sea navigation system. Mark the geological survey.

In addition, when the approachable soil level is reached, the screw auger's excavation speed is kept constant, the RPM is recorded and estimated from the current value, and the method of checking the groundable soil level with RPM is unclear due to the uncertainty of the soil layer. And the RPM method is used a lot in the field, but it is used as a reference, and the columnar diagram should be clearly prepared and compared with the estimated penetration depth to check the operating current of the auger motor.

And the soil discharged by the screw auger is agitated, so it is difficult to confirm the exact lipids, but the soil discharge is confirmed by estimating the soil layer compared with the geological survey.

On the other hand, in consideration of on-site imagination and machine entry conditions, the pilots are carried out in as many places as possible to record the soil condition closely, and the expected pile penetration depth is displayed. In the case of a plan to be adjacent to within 30m, it is advantageous to do as much as possible.

In addition, the results of the sea rudder are indicated in the layout and cross-sectional view to indicate the position and range of the rudder, which is applied to the site. The slower the excavation speed, the better the result is obtained. Do not reverse rotation as the soil will fall under the hole.

As described above, the excavation and geological survey, the excavation by the casing and screw auger (step S40) is completed after confirming the soil layer which can be driven by the use current of the auger motor or by confirming the discharge soil, the sea rudder.

The cement paste mixers, compressors, and generators prepared in advance are collected and managed in one place, and the materials are added in the order of water and cement. The tip part is intruded by the rear helm, so the perforated part is cement (40 kg / m): water = It is used by mixing (S50), such as 1: 1.

When the cement paste is prepared, the casing protecting the void wall is left as it is until the cement paste is injected, and the cement paste is injected at a high pressure while gradually drawing a screw auger (step S60).

Then, the cement paste is stirred with the surrounding soil to improve the peripheral frictional force, and the extension head pile (2) strength is mostly formed by the tip bearing force, so the screw auger is reintruded for cement paste mixing and minimal slimming. (Step S70).

At this time, pay attention to the penetration depth so as not to damage the support base when screw auger penetration.

Accordingly, the screw auger again as slowly as possible (step S80).

Then, in line with the center of the perforation, and then set up to be perpendicular to the intrusion by gravity of the head-expanded pile, the cement paste may flow out during the penetration, so slowly infiltrate the pile to prevent this (step S90).

Subsequently, after the penetration of the head extension pile, the upper end of the pile is fixed with a screw auger tip (step S100), and the casing is gradually drawn out (step S110).

Accordingly, the impact relief material (not shown) is placed at the tip of the head extension pile and freely falls into the RAM to infiltrate the pile. (Step S120)

On the other hand, pay attention to the verticality of the file, shaking, and breaking of the tip when driving.When the verticality of the file is shifted, the file may be destroyed and affect the file strength. Match.

Then, if it is judged that the driving force reached the expected support layer (average penetration amount of 5 ~ 10mm in one type), the operation of the helm is stopped and the settlement is recorded after installation. Measure the amount.

In addition, the construction method in the case where there is soil which does not collapse during drilling, which is another construction method, among the construction methods of the head extension pile 2 will be described. 7 is basically the same as FIG. 7, and the process is the same as that of FIG. 8 without using a casing.

8 can also be more easily understood by the description of FIG. 8.

Selection of the file and the preparation and confirmation of the drive, and the preparation work such as obstacle handling (S200), and after the confirmation of the working ground and reinforcement of the ground to install the ride (S210).

And the screw auger 62 to check the verticality of the screw auger 62 and the leader 64 in the front and side fixed (S220), excavation and geological survey, by the operating current of the auger motor or discharged soil, After confirming the ground layer that can be driven by the check of the rudder, etc., the excavation by the screw auger 62 is performed (S230).

In other words, the preparation of the pile, the preparation and confirmation of the drive, and the preparation work step (S200), such as obstacle handling, and the step of preparing the installation of the ride after confirmation of the working ground and reinforcement of the ground (S210), and screw auger from the front and side The screw auger position fixing step (S220) to check the verticality of the leader is completed the preparation process.

In the step (S200), the file is selected in the head-extended file of the present invention advantageous to the front end support, and identified to remove the ground or underground obstacles.

In the step of preparing to install the helm (S210) after checking the navigating equipment and facilities according to the ground, and confirms the abnormality, and confirms the stability of the working ground of navigating equipment. This may affect the auger's verticality and pile driving, and prevent safety accidents during construction.

In the screw auger position fixing step (S220), check the verticality at two points perpendicular to the front of the auger and reinforce it by laying a perforated plate and rubble if it is inclined or moved.

Then, the excavation and geological survey, the excavation step (S230) by the screw auger is carried out after confirming the soil layer which can be driven by the use current of the auger motor or by confirming the discharge soil, the time struck, etc.

At the time of excavation, the screw auger is inserted and then the screw auger is rotated forward to gradually excavate (② of FIG. 9).

The slower the excavation speed is, the better the results will be. If the auger is reversed during the excavation, care must be taken as the soil will enter the ball and adversely affect the bearing capacity. When the drilling is completed to the top of the soil layer excavable by hitting (Fig. 9 ③), the auger is idling while spraying high pressure air in place while holding it slightly to remove the slimes (④ in Fig. 9).

This idling is one of the important processes, and it excretes all the slime accumulated in the auger during the excavation, so it can reduce the amount of slime mixed with the cement paste later to prevent the strength from dropping.

Next, while performing the step (S240) of mixing the cement paste in the order of water and cement using a dedicated mixer, the cement paste 66 is injected at high pressure (S260) while drawing the screw auger 62 (S250). ⑤ of 9).

Since the tip part is intruded by the rear rudder, the perforated part is mixed with cement: water = 1: 1 (use cement about 40Kg / m), and the screw auger is drawn as slowly as possible while injecting cement paste at high pressure. .

Next, the head extension pile 2 is erected vertically, and then slowly penetrated (S280) in order to prevent the cement paste 66 from flowing into its own weight (6, ⑦ in FIG. 9).

In this case, screw auger re-injection can be used selectively. If there is no slime, this process does not need to be used. The reason for reintroducing the screw auger 62 here is to agitate the cement paste and the surrounding soil to induce an improvement in peripheral friction.

In order to penetrate the shock-absorbing material (not shown) at the distal end of the head extension pile (2), the final struck is performed at a height of 2M to be struck to generate the final settlement amount (S290) (Fig. 9).

If it is determined that the anticipated support layer has been reached (5 ~ 10mm penetration per type), the driving is stopped for a while, the settlement recorder is installed, and the driving is carried out to measure the penetration and rebounds to measure the final settlement. Check (S300).

On the other hand, pay attention to the verticality of the file, shaking, and breaking of the tip when driving.When the verticality of the file is shifted, the file may be destroyed and affect the file strength. Match.

As such, when the pile is inserted using the embedding method up to the pile penetration step (S280), the tip support force is improved by the lower reinforcement part, and the tip support force as shown in Table 1 can be obtained.

Next, after the file penetration is carried out by performing the file struck step (S290), the lower reinforcement part is infiltrated by the driving by the device (RAM) to improve the file bearing capacity by injecting the rear driving surface (c) into the strength of the pile itself. Closer support can be achieved.

As described above, in the case of soil which collapses during drilling, the head extension pile (2) suitable for the load capacity is selected. 8 is performed as it is,

However, the casing installation step is included after the step installation step (S210), and the casing withdrawal step is included before the file beating step (S120). When the ground of the site has a soil layer in which the weathering zone is collapsed, the casing is used. This prevents collapsing of the wall and punctures up to the top of the ground capable of navigating the rudder.

In any construction method that is the same as or similar to the construction method as described above, all construction methods using the head extension file of the present invention fall within the scope of the present invention among those skilled in the art, and thus infringe the rights of the present invention.

For example, the construction method of directly injecting the head extension pile directly into the pipe, the construction method of inserting the head extension pile directly after drilling, or inserting the head extension pile directly into the steel pipe, concrete pipe, synthetic resin pipe, wood pipe, etc. Construction method and the construction method which penetrates a head extension pile by hydraulic, pneumatic, and chemical means are mentioned.

According to the present invention, the construction method of the pile is used without impacting the weight or volume of the pile used in the embedding method by using a construction method for driving after landfilling and removing the slime by idling the auger in the excavation stage Can reduce the number of files used in construction by increasing the file history to the file itself, which can greatly increase the efficiency and economical use of the file.

  Compared with the pile construction originally planned in the field, the head extension type pile was installed in the same way as before and the construction method of the present invention was applied. It was effective enough.

In addition, there is an effect to increase the construction strength of the pile, to ensure the stability, construction and economics of the pile strength during the construction of the pile supporting the load of the structure to increase the efficiency and economic efficiency of the pile.

Claims (2)

Selection of pile, preparation and confirmation of driving, preparation of operation step such as obstacle handling (S200), preparation of driving installation after confirmation of working ground and reinforcement of ground (S210), verticality of screw auger and leader in front and side Screw Auger position fixing step (S220) to be a preparatory process to confirm; Excavation step (S230) by screw auger to remove the slime by idling the auger while spraying high pressure air in place after confirming the completion of puncturing to the top of the possible soil layer (S230); Next, the step of mixing the cement paste in the order of water and cement using a dedicated mixer (S240) to inject the cement paste at a high pressure while drawing a screw auger (S250); After the injection of the cement paste and optionally re-injecting the screw auger for cement paste mixing and slime treatment (260), the head extension pile is vertically set up and then introduced into its own weight (S270); Method of constructing a head-extended pile, characterized in that the construction is performed in the order of the step (S290) in order to infiltrate the head-expanded pile after the file embedding process. The method of claim 1, In the preparation process, the step of installing the casing is included after the installation step (S210), and the casing drawing step is included before the pile rolling step (S290). A method of constructing a head extension pile, characterized in that the step of carrying out the rear helm to the support layer after the drilling to the top of the rudder capable soil layer of the helm.

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