KR102091646B1 - Ground improvement type composite pile construction method - Google Patents

Abstract

The present invention relates to a ground improvement type composite pile construction method. The method comprises the following steps of: performing foundation-trenching by excavating the ground; installing a heat support wall in the excavated part; stirring the ground by excavating the center of the head support wall downwards and mixing an amendment; installing a guide device inside the head support wall; inserting a pile in a vertical direction into the ground mixed with the amendment by using the guide device; and placing foundation concrete inside the head support wall. Since the skin friction force and point bearing force of the pile are enhanced at the same time by installing a shear reinforcing material outside the pile and a point ring in the bottom, even a small-diameter pile can have a support force similar to the support force of a large-diameter pile. Moreover, as the point ring installed in the bottom of the pile is used as an expanded point ring depending on the condition of the ground and a point fixing solution is injected into the ground in the bottom of the pile, the point bearing force of the pile can be enhanced to enable the pile to have a substantial support force even on a bedrock layer.

Description

Ground improvement type composite pile construction method

The present invention relates to a method for constructing a soil-reinforced synthetic pile, and more particularly, to a method for constructing a soil-reinforced synthetic pile in which the support capacity of the pile is increased by improving the soil and synthesizing the improved soil and pile.

In general, the pile foundation is a long columnar structure penetrated into the ground, and after the pile construction, the upper structures are installed on the upper side of the pile, and the pile supports the load generated by the upper structures.

At this time, the bearing capacity of the pile may be determined by combining the tip supporting force, which is the supporting force of the pile tip ground, and the principal surface frictional force, which is the frictional force generated between the pile outer peripheral surface and the surrounding ground.

However, in the related art, by inserting a ready-made pile inside the perforation tool, the tip supporting force is calculated only by the tip surface of the pile itself, and the main surface frictional force is calculated by the outer peripheral surface of the pile itself.

Therefore, when hard ground does not exist, a large depth pile is used to secure sufficient support, but a large depth pile has a problem in that large-scale equipment is put in, and the construction period and construction cost increase.

As a solution to the above problems, Korean Patent Registration No. 10-1669108 “Basic File Construction Method for Soft Ground” is disclosed. This prior art "step of drilling the ground (1) by a perforator to form an injection hole (11); Inserting an injection tube (21) in which a tube (40) formed of a waterproof and waterproof material is inserted into the injection hole (11) formed by the perforator; Injecting the instantaneous expansion composition (60) through the injection tube (21), the instantaneous expansion composition (60) expands the tube (40) and forms a foundation file in the form that the outer edge is expanded than the injection hole (11). Containing; containing, the tube is formed to have a wrinkle (43) curved along the longitudinal direction to expand the surface area when expanded by the instantaneous expansion composition injected therein, the instantaneous expansion composition (60) Is a high-density polyurethane, and the tube 40 is made of one selected from among waterproof and elastic rubber materials, synthetic rubber materials, and synthetic resin materials, forming an opening 41a and forming a ring shape, and the upper end of the body An inlet portion 41 formed to have a thicker thickness so that elasticity is smaller than the portion; A body portion 44 extending downward from the inlet portion 41 to form an inner accommodation space and having the wrinkles 43 curved along the longitudinal direction; The lower portion of the body portion 44 is formed to extend beyond the outer diameter of the body portion 44 and is formed in a structure having a closed base-forming portion 47; the base-forming portion 47 is square, top A method of constructing a foundation file for a soft ground characterized in that it is formed in a shape selected from any one of the molds (see claim 1). ”, The instantaneous expansion composition is injected into the soft ground to inflate it in a shielded state. It is an object of the present invention to provide a method for constructing a soft ground foundation file that can improve the workability while increasing the compaction density.

However, the prior art may increase the frictional force by increasing the frictional area between the pile and the ground by the instantaneous expansion composition, but since the expansion of the pile depends on the instantaneous expansion of the injection material, it is applicable only to the super soft ground, and the bearing capacity of the pile There is a problem that depends on the rigidity of the instantaneous expansion material.

In addition, as a solution to the above-mentioned problems, the Republic of Korea Patent Publication No. 10-2010-0124028 "tip-end field-type pile construction method" has been disclosed. This prior art "injecting the injection pipe 25 to the planned point of the field pour pile; When the tip of the injection pipe 25 reaches the planned depth of the cast-in-place pile, pressure-injecting the injection liquid 32; Drawing the injection tube 25 when the injection of the injection solution 32 and expansion in the ground are completed; When the injection liquid 32 is solidified in the ground to form the solidified body 33, the step of intrusing the casing 21 at the planned point of the cast-in-place pile and excavating the soil inside the casing 21; When the tip of the casing (21) reaches the solid body 33, retracting the drilling equipment 22 and detecting the drilling hole; Erecting a reinforcing bar network (23) into the casing (21); Pouring concrete 31 inside the casing 21 and drawing the casing 21 at the same time; As a method of constructing an extended type cast-in-place pile (see claim 1), characterized in that it consists of the steps of curing the concrete (31) and completing an integrated cast-in-place pile with the solidified body (33), the effective section of the tip of the pile foundation By expanding to induce mechanical behavior similar to that of spread footing, only the bearing capacity due to skin friction, as in high-water clay soils The purpose of this construction is to construct a pile that exhibits the desired lower end bearing capacity even in this effective soft ground.

However, the prior art has a problem of increasing the construction cost and the construction period by separately requiring a ground reinforcement work to reinforce the ground of the tip of the pile before constructing the pile.

In addition, in the step of detecting the excavation hole, if the lower end portion of the excavation hole does not reach the solid body 33, there is a problem in that the friction force is reduced due to the excavation hole which was first excavated.

In addition, it is necessary to secure the area of the ground to be reinforced as the tip supporting force of the pile is affected by the thickness of the ground reinforced, but there is a problem that the expected effect of the ground reinforcement is not large as the grouting effect is uncertain in the soft ground.

In addition, if the thickness of the reinforced ground is not large enough, settlement may occur under the soft ground due to the load acting after pile construction, which may cause serious problems in the bearing capacity of the pile.

Therefore, it can be applied not only to the soft ground, but also to the soil and rocky ground, and it is necessary to develop a technology that can increase the overall bearing capacity of the pile by increasing the main surface friction and tip support of the pile without the construction of large-diameter piles and large-scale piles. to be.

Patent 0001: Republic of Korea Registered Patent No. 10-1669108 Patent 0002: Republic of Korea Patent Publication No. 10-2010-0124028

In order to solve the above problems, the present invention is to provide a method for constructing a ground-improving synthetic pile that increases friction between the pile and the ground by installing a shear reinforcement on the outside of the pile.

In addition, by mixing and stirring the ground around the pile with the improved material, and to integrate the pile and the surrounding ground, it is intended to provide a method for constructing a ground-improving synthetic pile in which the main surface friction of the pile is increased.

In addition, by providing a tip ring at the bottom of the pile, it is intended to provide a method for constructing a ground-improving synthetic pile in which the tip supporting force of the pile is increased.

In addition, by using a tip ring installed at the bottom of the pile in an enlarged form and injecting a tip fixing solution, it is intended to provide a method for constructing a ground-improving synthetic pile in which the tip supporting capacity of the pile is increased.

A method for constructing a ground-reinforced synthetic pile according to an example of the present invention includes excavating a ground to dig a foundation; Installing a head support wall on the excavated site; Excavating the central portion of the head supporting wall downward and mixing the improved material to stir the ground; Installing a guide device inside the head supporting wall; And inserting the pile in the vertical direction to the ground in which the improved material is mixed using the guide device.

In addition, after the step of inserting the pile in the vertical direction, pouring a foundation concrete on the inside of the head support wall; And removing the head support wall.

In addition, between the step of inserting the pile into the ground and the step of pouring the foundation concrete, it is possible to further perform the step of injecting a fixation solution into the front end of the pile.

In addition, the pile may be formed with a shear reinforcement projecting outwardly, and integrated with the ground on which the improved material is mixed by the outer surface of the pile and the shear reinforcement.

In addition, the shear reinforcement may include shear bars installed through the pile, and nuts fastened to the protrusions of the shear bars.

In addition, the shear reinforcement may include a-shaped angles installed in contact with the pile, bolts for coupling the angles to the pile.

In addition, the shear reinforcement may include ring-shaped connection bands installed on the outer circumferential surface of the pile and angled angles welded to the connection band.

In addition, the bottom rings of the pile may be installed while spaced apart from each other in a fan-shaped tip ring along the circumferential direction.

In addition, support protrusions for securing space may be installed below the tip rings.

In addition, the guide device is installed to be spaced apart from each other up and down, a pair of guide couplers having a cylindrical shape, connecting members connecting the pair of guide couplers up and down, and the guide couplers to be mounted on the head support wall. It may include mounting members.

In addition, the guide coupling tool further includes guides installed while being spaced apart from each other along the circumferential direction, and the guides can guide the pile to be well inserted in the vertical direction.

In addition, the mounting member may further include a fixing member installed between adjacent mounting members, and the fixing member may include a fixing hole into which a fixing key installed on the head support wall is inserted.

Through the present invention, by installing a shear reinforcement on the outside of the pile, the friction between the pile and the ground can be increased.

In addition, by mixing and stirring the ground around the pile with the improved material, the pile and the surrounding ground are integrated, so that the main surface frictional force of the pile can be increased.

In addition, by installing a tip ring at the bottom of the pile, the tip supporting force of the pile can be increased.

In addition, by using the tip ring installed at the bottom of the pile in an enlarged form and injecting the tip fixing liquid, the tip supporting force of the pile can be increased.

1A to 1H are flowcharts illustrating a construction procedure of a method for constructing a ground-heavy synthetic pile according to an example of the present invention.
Figure 2a is a view of the construction of the pile on the ground with a deep support layer by the ground improvement type synthetic pile construction method according to an example of the present invention.
Figure 2b is a view of the construction of a pile on a shallow ground support layer by the ground improvement type synthetic pile construction method according to an example of the present invention.
3A is a plan view showing the guide device.
3B is a side view showing the guide device.
3C is a view showing a state in which a guide device is installed.
3D is a cross-sectional view showing a cross-section AA in FIG. 3C.
Fig. 3E is a cross-sectional view showing the BB section of Fig. 3C.
3F is a cross-sectional view showing the cross-sectional view of FIG. 3C.
3G is a side view and a plan view showing a state of inserting a pile using a guide device.
3h is a view showing a state in which a shear reinforcement is coupled to a pile and a pile is inserted using a guide device.
Fig. 3I is a cross-sectional view showing the AA section in Fig. 3H.
3J is a cross-sectional view showing the BB section of FIG. 3H.
4 is a side view and a cross-sectional view showing a state in which a shear reinforcement of various embodiments is installed on a pile.
5A is a side view and a cross-sectional view showing a state in which a tip ring of a pile is installed.
5B is a side view and a cross-sectional view showing a state in which an enlarged tip ring of a pile is installed.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, the same components have the same reference numerals as possible even though they are displayed on different drawings. In addition, in describing embodiments of the present invention, when it is determined that detailed descriptions of related well-known configurations or functions interfere with understanding of the embodiments of the present invention, detailed descriptions thereof will be omitted.

In addition, in describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only for distinguishing the component from other components, and the nature, order, or order of the component is not limited by the term. When a component is described as being "connected", "coupled" or "connected" to another component, the component may be directly connected to or connected to the other component, but another component between each component May be "connected", "coupled" or "connected".

Hereinafter, a method for constructing a ground-improving synthetic pile according to an example of the present invention will be described in detail with reference to FIGS. 1 to 5.

Referring to Figure 1 or 2, the ground improved synthetic pile construction method according to an example of the present invention, the step of excavating the foundation by excavating the ground; Installing a head support wall (20) on the excavated site; A step of excavating the central portion of the head support wall 20 downward and mixing the improved material 30 to stir the ground; Installing a guide device (40) inside the head support wall (20); Inserting a pile (10) in a vertical direction into the ground on which the improved material (30) is mixed using the guide device (40); Can be applied in order.

This embodiment relates to a pile construction method for inserting a pre-made pile into the ground. This embodiment relates to a technique for increasing the bearing capacity of the pile 10 by using a small-diameter hollow pile and increasing the bonding force with the ground around the pile 10.

The step of excavating the foundation is a step of excavating the upper side of the ground on which the pile 10 is to be constructed, thereby excavating the foundation. The foundation digger may install a guide device 40 for guiding the pile 10 and at the same time excavate to the extent that the foundation concrete 50 is poured.

The step of installing the head supporting wall 20 is a step of installing the head supporting wall 20 on the excavated ground. The head support wall 20 can prevent the collapse of the excavated ground. The head support wall 20 can firmly support the guide device 40 to be described later. A fixed key 21 may be installed around the upper inner circumference of the head support wall 20. The guide device 40 can be precisely mounted by the fixing key 21.

The step of stirring the ground is a step of excavating the central portion of the head support wall 20 downward and mixing the improved material 30 to stir the ground. In this step, the ground can be improved by excavating the ground with an auger or the like on the lower side of the central portion of the head support wall 20 and mixing the improved material 30 into the excavated ground. The improved material 30 can be produced by mixing cement, water, and the like.

The improved ground has increased stiffness and adhesion, so that the bonding force between the pile 10 and the improved ground is increased, so that the supporting force of the pile 10 can be increased. In addition, as the improved ground is coupled to the pile 10, the main surface frictional force is increased by the improved ground, so that a small-diameter pile can have the same bearing capacity as a large-diameter pile.

The step of installing the guide device 40 is a step of installing the guide device 40 inside the head support wall 20. The guide device 40 may guide the pile 10 to be accurately inserted in the vertical direction.

Referring to Figure 3, the guide device 40 is installed spaced apart from each other up and down, a pair of guide fittings 41 having a cylindrical shape, and a connecting member 411 connecting the pair of guide fittings 41 up and down ), May include a mounting member 413 for mounting the guide coupling 41 to the head support wall (20).

The guide fitting 41 may have a cylindrical shape. The cylindrical shape can be applied when the pile 10 is circular. For example, when the pile 10 is a square, the guide coupling hole 41 may also be a square.

The pair of guide fittings 41 installed up and down may be connected by welding or the like by the connecting members 411. The connecting members 411 may be angled angles made of steel. The connecting members 411 can directly connect the pair of guide fittings 41. In addition, the connecting members 411 may interconnect the upper and lower flanges coupled to the side surfaces of the pair of guide fittings 41. The flange may be coupled by welding or the like in the horizontal direction around the guide fitting 41.

The mounting members 413 may be coupled to the guide fitting 41 by welding or the like, coupled to the connecting member 411, or coupled to the flange. The mounting members 413 may extend horizontally and be mounted on the head support wall 20.

The guide device 40 may further include a fixing member 415. The fixing member 415 may be installed between adjacent mounting members 413 among the mounting members 413. A fixing hole 417 may be formed in the fixing member 415. A fixing key 21 installed at an upper end of the head supporting wall 20 may be inserted into the fixing hole 417. That is, by inserting the fixing key 21 into the fixing hole 417, the guide device 40 can be mounted to the head supporting wall 20 precisely and firmly. Therefore, the pile 10 can be precisely inserted by a pair of guide fittings 41 and guides 43 installed inside the guide fittings 41 to be described later.

The guide device 40 may further include guides 43 that are installed while being spaced apart from each other along the circumferential direction inside the guide coupling tool 41. The guides 43 are spaced apart from each other on the inside of the guide coupling tool 41 and can be coupled by welding or the like. In addition, the guides 43 are coupled to a coupling band installed around the outside of the guide coupling hole 41 and the coupling band can be bolted to the guide coupling hole 41. The inner circumferential surface of the guides 43 may be installed to correspond to the outer circumferential surface of the pile 10 to guide the pile 10 so that it is well inserted in the vertical direction.

The step of inserting the pile 10 in the vertical direction is a step of inserting the pile 10 in the vertical direction on the ground in which the improved material 30 is mixed using the above-described guide device 40. Shear reinforcement 11 is installed on the outside of the pile 10, the tip ring 13 may be coupled to the bottom. The guides 43 spaced apart from each other can allow the shear reinforcement 11 and the tip ring 13 to be well inserted without jamming.

Referring to FIG. 4, in this embodiment, the shear reinforcement 11 installed outside the pile 10 is fastened to the protrusions of the shear reinforcing bars 111 and the shear reinforcing bars 111 installed through the pile 10. Nuts 113 may be included.

That is, after installing the shear reinforcing bars 111 to penetrate the pile 10, the nuts 113 are fastened to both exposed ends to be firmly coupled to the pile 10. The shear reinforcing bars 111 may be installed spaced apart from each other in the circumferential direction, and may be staggered so as not to overlap each other in the vertical direction.

Another embodiment of the shear stiffener 11 may include a-shaped angle 115, which is installed in contact with the pile 10, bolts 117 for coupling the angles to the pile 10. The shear stiffener 11 of this embodiment can be installed by contacting the angled angles 115 so as to be spaced apart at regular intervals along the periphery of the pile 10 and fastening the bolt 117 to be coupled to the outer circumferential surface of the pile 10. . That is, the vertical flange of the angled angle 115 is in contact with the side of the pile 10, the horizontal flange at the top or bottom of the vertical flange can be extended in the horizontal direction.

Another embodiment of the shear reinforcement 11 may include ring-shaped connection bands 119 installed on the outer circumferential surface of the pile 10 and angled angles 115 welded to the connection band 119. . The connection band 119 is installed to be in close contact with the outer circumferential surface of the pile 10 and then fastened with a bolt 117, and can be combined by welding the angled angles 115 to be spaced apart from each other on the outside of the connection band 119.

The pile 10 on which the shear reinforcement material 11 is installed may be inserted into the ground in which the improved material 30 is mixed to be integrated with the ground in which the improved material 30 is mixed. Therefore, the ground and the pile 10 agitated by the improved material 30 may be integrated, thereby significantly increasing the bearing capacity of the pile 10.

5, the lower end of the pile 10 may be installed while the tip rings 13 having a fan shape along the circumferential direction are spaced apart from each other.

The tip ring 13 can be coupled by arranging a plurality of them so as to be spaced apart from each other on the lower outer circumferential surface of the pile 10. The tip ring 13 may increase the overall bearing capacity of the pile 10 by increasing the tip supporting force of the pile 10 by increasing the diameter of the tip of the pile 10.

Support protrusions 131 for securing space may be installed under the tip ring 13. A space is secured at the lower end of the pile 10 by the support protrusion 131, so that the tip fixing liquid can be easily injected into the ground at the lower end of the pile 10.

The tip ring 13 may use an enlarged tip ring 13 according to the ground characteristics of the tip of the pile 10. The enlarged tip ring 13 may be formed by enlarging the size of the existing tip ring 13.

In this step, the pile 10 may be inserted by vibration using a hammer as a vibrator. By using a hammer as a vibrator, the pile 10 can be easily inserted into the improved ground.

After the step of inserting the pile into the ground, the step of injecting the tip fixing fluid into the bottom ground of the pile 10 may be further performed. This step can be performed when the pile 10 is inserted up to the support layer where the rock is present. That is, by injecting the tip fixing liquid into the tip of the pile 10, the tip of the pile 10 can be stably fixed to the support layer by the tip fixing liquid. An injection tube may be installed inside the pile 10 to inject the tip fixation solution.

After the step of inserting the pile 10 in the vertical direction, the step of pouring the foundation concrete 50 inside the head support wall 20 may be further performed.

The step of pouring the foundation concrete 50 is a step of pouring the foundation concrete 50 inside the head support wall 20. In this step, after completing the insertion of the pile 10 in the vertical direction, the guide device 40 is disassembled and the foundation concrete 50 is placed inside the head supporting wall 20 to be integrated with the head of the pile 10. can do. After the head of the pile 10 and the foundation concrete 50 are integrated, a subsequent process may be performed.

After pouring the foundation concrete 50, the step of removing the head support wall 20 may be further performed. The head support wall 20 can be recycled to another pile 10 construction.

In the above, even if all the components constituting the embodiments of the present invention are described as being combined or operated as one, the present invention is not necessarily limited to these embodiments. That is, within the scope of the present invention, all the components may be configured or operated by selectively combining one or more components. In addition, the terms "include", "consist" or "have" as described above mean that the corresponding component can be intrinsic, unless specifically stated to the contrary, excluding other components. It should not be interpreted as being able to further include other components. All terms, including technical or scientific terms, have the same meaning as generally understood by a person skilled in the art to which the present invention pertains, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted as being consistent with the contextual meaning of the related art, and are not to be interpreted as ideal or excessively formal meanings unless explicitly defined in the present invention.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the claims below, and all technical spirits within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

10: Pile
11: Shear reinforcement
111: shear bar
113: nut
115: angled angle
117: bolt
119: connecting band
13: tip ring
131: support projection
20: head support wall
21: fixed key
30: improved material
40: guide device
41: guide fitting
411: connecting member
413: mounting member
415: fixing member
417: fixed hole
43: Guide
50: basic concrete

Claims (12)

Digging the ground to dig a foundation;
Installing a head support wall on the excavated site;
Excavating the central portion of the head supporting wall downward and mixing the improved material to stir the ground;
Installing a guide device inside the head supporting wall; And
Inserting a pile in the vertical direction to the ground in which the improved material is mixed using the guide device; constructing in order,
The guide device is installed to be spaced apart from each other up and down, a pair of guide couplers having a cylindrical shape, connecting members connecting the pair of guide couplers up and down, and a mount for mounting the guide couplers to the head support wall A method for constructing a ground-reinforced synthetic pile comprising members. The method according to claim 1,
After the step of inserting the pile in the vertical direction,
Pouring foundation concrete on the inside of the head support wall; And
Removing the head support wall; Ground improvement type synthetic pile construction method further performing. The method according to claim 2,
Between the step of inserting the pile to the ground and the step of pouring the foundation concrete, the method of constructing the ground-modified synthetic pile further comprising the step of injecting a tip fixing solution into the ground at the bottom of the pile. The method according to claim 1,
The pile has a shear reinforcement projecting outwardly, and the ground improvement type synthetic pile construction method integrated with the ground on which the improved material is mixed by the outer surface of the pile and the shear reinforcement. The method according to claim 4,
The shear reinforcement is a ground-reinforced synthetic pile construction method comprising shear bars installed through the pile, nuts fastened to the protrusions of the shear bars. The method according to claim 4,
The shear reinforcing material is a ground-shaped synthetic pile construction method comprising a-shaped angles installed in contact with the pile, bolts for coupling the angles to the pile. The method according to claim 4,
The shear reinforcing material is a ground improved synthetic pile construction method comprising ring-shaped connection bands installed on the outer circumferential surface of the pile, and angled angles welded to the connection band. The method according to claim 1,
A method of constructing a ground-improving synthetic pile in which the tip rings having a fan shape are spaced apart from each other along the circumferential direction at the bottom of the pile. The method according to claim 8,
A method for constructing a ground-reinforced synthetic pile in which support protrusions for securing space are installed below the tip rings. delete The method according to claim 1,
The guide coupling tool further includes guides installed while being spaced apart from each other along the circumferential direction,
The guides are ground improvement type synthetic pile construction method to guide the pile so that it is well inserted in the vertical direction. The method according to claim 1,
A method of constructing a semi-improved synthetic pile, further comprising a fixing member installed between adjacent mounting members among the mounting members, wherein a fixing hole in which a fixing key installed in the head supporting wall is inserted is formed in the fixing member.

Images