KR100455915B1 - Micropile type packer and method for constructing micropile of pressure type using the micropile type packer - Google Patents

Abstract

The present invention relates to a micro pile packer suitable for maximizing the reinforcement effect of the ground and a pressure type micro pile construction method for easy construction and quality control through pressure grouting using the micro pile packer. The packer is cylindrical in shape and has a predetermined length, and is inserted and fixed at both ends of the nonwoven fabric, respectively, to seal the cylindrical space, and a plurality of penetrating materials, grouting injection pipes, foam urethane injection pipes, air and foreign material discharge pipes can penetrate. A first packing and a second packing having a through hole, wherein the first packing and the second packing include a hole through which the reinforcing material penetrates, a hole through which a grouting tube for injecting the grout chemical liquid penetrates; Air for discharging air and foreign substances generated during grouting to the outside of the drilling hole Is provided with a hole to discharge the foreign matter through common, it characterized in that it includes a hole which is expanded urethane injection pipe for injecting a foaming urethane drug solution through the said enclosed space, the first packing.

Description

Packer for micropile and pressure micropile construction method using the same {micropile type packer and method for constructing micropile of pressure type using the micropile type packer}

The present invention relates to a micropile, and more particularly, to a packer for a micropile suitable for reinforcing bearing capacity of a foundation ground, a soft ground, a surrounding ground, and a pressure micropile construction method using the same.

In general, all buildings must have sufficient bearing capacity to support the building, or else settlement will occur at the top or deep of the foundation, greatly affecting the stability of the building built on it.

Therefore, before erecting a building, it is necessary to investigate whether the soil bearing capacity is able to withstand the weight or load applied to the ground by the building through suitable surveys such as geological surveys and soil surveys. In the case of soil, peat land, wetland, soil with significant change in water content, soil with large gaps or uneven ground, the supporting ground is not sufficient, so the greater the supporting capacity is required. do.

In addition, in order to strengthen the foundation of the ground structure, a number of piles are embedded in the soft ground, or a wide and deep earth is excavated, the foundation is made of reinforced concrete, and then the structures are constructed on it. When facilities are installed, the conditions for strengthening the foundation are often not formed, and when the foundation is widely sold without knowing the location of underground buried materials, it may cause damage to facilities such as electricity or gas piping.

Therefore, it is well known that the pile foundation reinforcement method is used as a method for securing the bearing capacity on the foundation ground in consideration of the above points, and in addition, the rod and A variety of methods have been proposed, including grouting, which involves drilling using a bit, inserting steel pipes such as reinforcing bars into the drilled holes, and injecting reinforcing fluids (grouting fluids). Micro pile is a typical example.

The micro pile began in Italy in the fifties and has been constructed as a substitute for ground reinforcement and piles around the world. The micro pile, micro pile, root pile, needle pile, and gewi pile have been applied according to the purpose and scope of application by country. It is called the back.

Such micro piles can withstand vertical and horizontal forces and, depending on the design concept, may be used as a substitute for the pile foundation reinforcement method or as a component of the ground / pile composite, and have minimal impact on surrounding structures, ground, and the environment. It is possible to construct in all kinds of soil conditions that are difficult to construct, and has the advantage that it can be installed at any angle below the horizontal by ground anchor or grouting construction equipment.

The bearing capacity of the micro pile is determined by external factors (related to the ground), but the allowable load of the pile is determined by internal factors (components of the pile), so both external and internal factors are considered simultaneously in the design. Must be reflected in the design.

Hereinafter, a method of constructing a micropile according to the related art will be described with reference to the accompanying drawings.

1 is for explaining a method of constructing a reinforcing micro pile according to the prior art, and shows a state in which a reinforcing micro pile is installed in a drilling hole.

Reinforced micro piles are drilled in small diameters, so the equipment can be constructed with small equipment and little noise and vibration. It is used for residential and narrow places in the city center. In addition, it is more economical than the pile foundation reinforcement method because it can support a large load compared to the diameter of pile body, and amber stone is made by drilling pile to form pile body to support the working load by the main surface friction force of ground and grouting liquid. Installation is possible even if the reserved stone layer or support layer is located deep.

The construction method of such a reinforcing micro pile will be described in detail as follows.

The construction method of the reinforcement micro pile is largely composed of a drilling step, a pile installation step, and a grouting step.

First, the drilling uses bits with various diameters such as 76mm, 80mm, 90mm, 105mm, 115mm, 152mm, and 165mm in diameter, and in particular, more than 200mm bits are used. Install the casing till and drill the inside with a bit to form a hole.

At this time, the rock water or slime is removed by using fresh water as the working water during drilling, and the borehole's hollow wall becomes irregular because the rock piece or slim is discharged between the casing and the hollow wall, and the diameter of the drilling hole is larger than the casing diameter. As a result, the principal surface friction of the pile is improved.

When the drilling operation is completed, as shown in FIG. 2, the pile 21 combined with one reinforcing bar or three or more reinforcing bars is inserted. Usually, the material of the pile body 21 selects the material suitable for a ground characteristic and allowable load.

Since the reinforcing bars forming the pile 21 are three or more, the space between the reinforcing bars and the reinforcing bars is locally narrow so that when grouting, the cavity is not sufficiently filled and sometimes a cavity is formed. Therefore, the spacers 22 are installed at predetermined intervals so that the grouting chemical can be sufficiently filled in the hole when grouting.

Subsequently, when the pile is installed in the hole, grouting liquid is injected. That is, gravity grouting is performed immediately after the pile body is installed in the drilling hole. At this time, to compensate for the shrinkage of the grout chemical solution 23 is repeated about 3 to 6 times.

When the grouting is completed, the steel plate is fixed with a nut or welded on the top to ensure the clamping effect by ensuring the continuity of the structure and the pile so that the load of the structure is transferred to the pile. When the tofu cleansing is performed, the construction of the micropile according to the prior art is completed.

However, the conventional micropile construction method as described above has a limitation that it is used only when the pile having a low bearing capacity or the foundation ground which is installed in hard clay soil is a rock, and the pile is smaller because its diameter is smaller than its length. The tip bearing capacity of the micropile is not generally considered in the design because the tip area of is too small for the surrounding area.

In addition, in grouting, the grouting liquid is filled through the tube from the bottom of the punching hole and injected until it flows out to the inlet of the punching hole. The grouting is long and the grouting is performed 3 to 6 times to compensate for shrinkage. Since it is repeatedly performed, the workability is lowered and the construction period is longer, and the injection pressure cannot be maintained. Therefore, it is difficult to check the filling state and to control the quality.

The present invention has been made to solve the above problems of the prior art, an object of the present invention is to provide a packer for a micro pile suitable for maximizing the reinforcement effect of the ground.

Another object of the present invention is to provide a pressure-type micropile construction method using a micropile packer that is easy to shorten the construction period and control quality through pressure grouting using a micropile packer.

1 is a construction state diagram for explaining a gravity micropile according to the prior art

2 is a block diagram of a pile according to the prior art

3 is a block diagram of a packer for a micropile of the present invention

4A to 4B are configuration diagrams of the first and second packings of FIG.

5 is a state in which the reinforcing material, grouting pipe, polyurethane foam pipe, air and foreign matter discharge pipe is installed in the micro pile packer of the present invention;

Figure 6a to 6f is a state diagram for each step for explaining the pressure-type micropile construction method using the micropile packer of the present invention

7A and 7B are front views of FIGS. 6B and 6E, respectively.

* Description of the symbols for the main parts of the drawings *

31: nonwoven fabric 33a, 33b: first, second packing

51: H-beam 53: grouting pipe

53a: grout chemical solution 55: air and foreign substance discharge pipe

57: urethane foam injection tube 57a: polyurethane foam liquid

The micro pile packer of the present invention for achieving the above object is a micro pile packer inserted into the upper end of the inner diameter of the drilled hole in the ground during the construction of the micro pile for reinforcing the ground, a nonwoven fabric having a predetermined length in a cylindrical shape, A first packing and a second packing having a plurality of through-holes inserted into and fixed to both ends of the nonwoven fabric to seal the cylindrical space and through which a reinforcing material, grouting injection pipe, foam urethane injection pipe, air and foreign material discharge pipe can pass Characterized in that it comprises a packing.

At this time, the first packing and the second packing is a hole through which the reinforcing material penetrates, a hole through which the grouting tube for injecting the grout chemical liquid penetrates, and discharges air and foreign substances generated during grouting to the outside of the drilling hole. A hole through which the air and the foreign substance discharge pipe for passing through is commonly provided, and the first packing is further provided with a hole through which the polyurethane injection pipe for injecting the foamed polyurethane chemical liquid into the sealed space.

In addition, the outer side of the non-woven fabric along the outer peripheral surface of the first, second packing and the non-woven fabric for joining the first, second packing and the non-woven fabric, the screw is tightened to the non-woven fabric of the first, second packing It is preferable that the wire ring closely attached to the outer peripheral surface is further provided.

In addition, the hole through which the reinforcing material penetrates preferably has an H shape so that the H-beam can penetrate.

The pressure micropile construction method using the micro pile packer of the present invention comprises the steps of drilling a hole in the ground to a predetermined depth, the reinforcing material, grouting pipe, foam urethane injection pipe, air and Inserting a micro pile packer having a foreign substance discharge pipe into the perforated hole, injecting a foam urethane chemical solution through the foam urethane injection tube to expand the volume of the micro pile packer, and the inner diameter of the micro pile packer and the perforated hole. The step of intimately adhering to each other and injecting grout chemical liquid while maintaining a predetermined pressure through the grouting injection tube penetrating the micropile packer to grout in the perforated hole at the bottom of the micropile packer; At the same time, air and foreign substances generated during grouting Including the air, and the method comprising the perforations to the outside through the exhaust pipe to remove foreign matter, the method comprising: performing a head clean to handle cement ground surrounding the perforations characterized in that formed.

Here, after inserting the micro pile packer into the perforated hole, preferably further comprising the step of grouting the upper portion of the micro pile packer.

In addition, as the reinforcing material, any of an H-beam, a deformed steel bar, and a steel pipe pile may be used.

In addition, the grouting pipe is installed so that its end is located near the bottom of the perforated hole, the air and foreign matter discharge pipe is installed so that the end thereof is close to the lower end of the micro pile packer, the foam urethane injection pipe is the end It is preferable to install so as to be located between the first packing and the second packing.

EXAMPLE

Hereinafter, with reference to the accompanying drawings will be described a micro pile packer and a pressure-type micro pile construction method using the same.

3 is a configuration diagram of a micro pile packer of the present invention, Figures 4a to 4b is a front view of the first to second packing according to the micro pile packer of Figure 3, Figure 5 is a reinforcement ( As an example, a state diagram showing a state in which an H-beam) and various tubes (tubes) are inserted.

First, as shown in Figs. 3 and 4A to 4B, the packer for micropile of the present invention is largely cylindrical and has a nonwoven fabric 31 having a predetermined length and a first insert inserted at both ends of the nonwoven fabric 31. A first packing 33a and a second packing 33b, and the first packing 33a and the second packing 33b are holes through which an H-beam, which is commonly a reinforcing material, passes (hereinafter, the first hole and the first packing). 2 holes) 35a and 35b, holes through which grouting pipe for injecting grouting liquid (hereinafter referred to as third and fourth holes) 35c and 35d, and air and foreign matter for removing air and foreign matter The discharge pipe has holes (hereinafter, fifth and sixth holes) 35e and 35f through which the first packing 33a is sealed between the first packing 33a and the second packing 33b. It has a hole (hereinafter seventh hole) 35g through which a foam urethane injection pipe for injecting foam urethane into the space passes.

Here, the nonwoven fabric 31 surrounds the outer circumferential surfaces of the first packing 33a and the second packing 33b to seal an empty space between the first packing 33a and the second packing 33b, and It can be replaced by a tent or the like, and if it is a material that can sufficiently withstand the pressure due to the volume expansion of the polyurethane to be injected into the empty space between the first packing 33a and the second packing 33b. It may be.

In addition, the materials of the first packing 33a and the second packing 33b may be rubber, soft plastic, wood, iron plate, etc. Of these, the rubber material is most preferable as the material of the packing. That is, when the rubber packing is used, it is possible to bind more tightly between the grouting pipe, the air and the foreign substance discharge pipe, the foam urethane injection pipe, and the like which will be described in more detail below.

Meanwhile, FIG. 5 is a state in which the H-beam 51 and the grouting pipe 53, the air and foreign substance discharge pipe 55, and the foam urethane injection pipe 57 are inserted into the packer for the micro pile of the present invention as shown in FIG. As shown in the figure, the H-beam 51 penetrates the first hole 35a and the second hole 35b provided in the first packing 33a and the second packing 33b. The grouting pipe 53 is also inserted through the third hole 35c and the fourth hole 35d provided in the first packing 33a and the second packing 33b. The air and foreign substance discharge pipe 55 is inserted through the fifth hole 35e and the sixth hole 35f. However, the urethane foam injection tube 57 is inserted through the seventh hole 35g provided in the first packing 33a such that its end is located between the first packing 33a and the second packing 33b.

The air and foreign matter discharge pipe 55 is not only to discharge the foreign matters such as air or water generated in the grouting area due to the injection of the grout chemical liquid to the outside of the hole, but also to remove the air and foreign matters and then close the inlet. Allow pressure to be applied to the grouting area. At this time, when the pressure is applied to the grouting region, the grout chemical liquid is solidified, and the grout chemical liquid is tightly filled even in the voids or joints formed in the ground around the perforation hole by the pressure to improve the overall stability of the micropile. There is a number.

The urethane foam injection tube 57 is filled with a urethane chemical solution between the first packing 33a and the second packing 33b to gel in a closed space between the first packing 33a and the second packing 33b. Proceeds, thereby accompanied by volume expansion. In general, urethane chemicals have the advantage of controlling various physical properties such as expansion ratio, mechanical strength, etc., and in fact, the time for the urethane chemicals to be gelated is only a few minutes, so that they are filled in the space enclosed by the nonwoven fabric 31. If you do, you will be able to inject the grout in a short time.

A wire ring 37 is installed on the outer side of the nonwoven fabric 31 to tightly bond the nonwoven fabric 31 and the first and second packings 33a and 33b to each other. It is injected between the first packing 33a and the second packing 33b to enable firm support even when the volume is expanded.

6A to 6F illustrate a construction procedure for explaining the micropile construction method using the micropile packer of the present invention. FIG. 7a is a front view of FIG. 6b and FIG. 7b is a front view of FIG. 6e.

First, as shown in FIG. 6A, the soft ground on which the micro pile is to be installed is drilled using a rock drill or a boring machine to form a drill hole 61.

Thereafter, as shown in FIG. 6B, the packer for the micro pile into which the H-beam 51, the grouting tube 53, the air and foreign substance discharge tube 55, and the urethane foam injection tube 57 are inserted as the reinforcement material is described above. It is installed in the upper end in the drilling hole 61. 6B is a cross-sectional view taken along the line A-A 'of FIG. 7A. In fact, air and the foreign substance discharge pipe 55 are not shown, but are shown in the drawing for convenience of description. For reference, in addition to the H-beam 51 as the reinforcing material may be used to assemble a plurality of deformed steel reinforcement or use as a steel pipe pile.

Thereafter, as shown in FIG. 6C through the foam urethane injection tube 57, the foamed polyurethane chemical liquid 57a is injected between the first packing 33a and the second packing 33b. At this time, the foamed urethane chemical solution 57a is gelled at a very high rate, and after only a few minutes have elapsed after the injection of the chemical liquid, the foamed urethane solution becomes a gel state, thereby causing a volume expansion, thereby expanding the nonwoven fabric 31 to the above. The diameter of the nonwoven fabric 35 is in close contact with the inner diameter of the drilling hole.

Subsequently, as shown in FIG. 6D, the drill hole 61 in the upper portion of the micropile packer is filled with grout chemical liquid 53a such as cement milk, and then sintered for a predetermined time, and then as shown in 6e. Through the grouting tube 53, a grout chemical solution 53a, such as cement milk, is injected. At this time, since the end of the grouting tube 53 is located near the bottom surface of the drilling hole 61, the grout chemical solution 53a injected through the grouting tube 53 is filled from the bottom of the drilling hole 61.

After the grout chemical is sufficiently filled from the bottom of the drilling hole 61 to the bottom of the packer for the micropile, the air or the foreign matter generated in the process of filling the grout chemical through the air and the foreign matter discharge pipe 55 It is discharged to the outside of the drilling hole (61). Therefore, in order for the air and the foreign matters to be easily discharged to the outside, the ends of the air and the foreign substance discharge pipe 55 may be located near the lower end of the packer for the micropile. At this time, immediately after the discharge of the foreign matter is sealed by closing the air and the foreign substance discharge pipe is carried out pressure grouting. The grout chemical solution 53a is injected at a pressure of 5-10 kg / cm 2, and the grout chemical solution 53a is preferably a cement grout. At this time, the cement grout is adjusted to the weight ratio (w%) of water and cement in the range of 0.45 to 0.50.

As described above, the micropile method of the present invention injects the grout chemical at a pressure, so that the grout chemical penetrates along the pores and the joint surface of the ground, thereby maximizing the efficiency of the reinforcing effect, and the conventional gravity grouting prevents shrinkage. In order to repeat the grouting 3 to 6 times to take a lot of time, while the present invention completes the grouting in the drilling hole 61 by one grouting, the process time is reduced by that much.

When the grouting is completed as described above, as shown in FIG. 6F, when the tip of the micropile is treated with cement 65 to further strengthen adhesion to the surrounding ground, the micropile construction of the present invention is completed. do.

Although the preferred embodiments of the present invention have been described above, it is clear that the present invention can use various changes, modifications, and equivalents, and that the above embodiments can be appropriately modified and applied in the same manner. Accordingly, the above description is not intended to limit the scope of the invention as defined by the following claims.

As described above, the micro pile packer of the present invention and the pressure-type micro pile construction method using the same have the following effects.

First, since the H-beam is used as the reinforcing material, the reinforcing effect can be maximized.

Second, the pressure grout minimizes the grout frequency and the setting time, thereby reducing the construction period.

Third, since the pressure is maintained at the time of injection of the grout chemical solution to ensure a good filling of the grout chemical solution it is easy to quality control later.

Fourth, since pressure grouting is used, sufficient grout medicament is filled into voids or joint surfaces of soft soil such as sandy soil, so that the effect of ground improvement can be maximized, and in clay soil, the ground compacting effect can be maximized.

Claims (8)

As a micro pile packer inserted into the upper part of the inner diameter of the drilled hole drilled on the ground when the micro pile is constructed for reinforcing the ground, A nonwoven fabric having a predetermined length in a cylindrical shape; Inserted and fixed at both ends of the nonwoven fabric to seal the cylindrical space, and provided with a plurality of through holes through which reinforcement, grouting injection tube, polyurethane urethane injection tube, air and foreign substance discharge pipe can pass, and tightening of wiring A first packing and a second packing tightly bonded to the nonwoven fabric by The first packing and the second packing has a hole through which the reinforcing material penetrates, a hole through which a grouting tube for injecting the grout chemical liquid penetrates, and air for discharging air and foreign substances generated during grouting to the outside of the drilling hole. And a hole through which the foreign substance discharge pipe passes in common, and the first packing further includes a hole through which the polyurethane urethane injection pipe penetrates the urethane liquid into the closed space. The hole through which the reinforcing material penetrates the micro pile packer, characterized in that it has an H shape so that the H-beam can penetrate. delete The method of claim 1, wherein the wiring is provided on the outer side of the non-woven fabric along the outer peripheral surface of the first, second packing for micropile characterized in that the non-woven fabric tightly bonded to the outer peripheral surface of the first, second packing. Packer. delete Drilling holes in the ground to a predetermined depth; Inserting a micro pile packer in which the reinforcement, grouting pipe, foam urethane injection pipe, air and foreign matter discharge pipe are installed to extend over the upper end of the perforated hole in the perforated hole; Injecting the urethane foam liquid through the urethane foam injection tube to expand the volume of the micro pile packer to closely contact the inner diameter of the micro pile packer and the perforated hole; Air generated during grouting and grouting in the perforated hole at the bottom of the micropile packer by injecting grout chemical liquid while maintaining a predetermined pressure through the grouting injection tube passing through the micropile packer. Discharging the foreign matter to the outside of the drilling hole through the air and the foreign substance removing pipe; Pressure micropile construction method using a micro-packer characterized in that it comprises the step of performing the tofu to clean the cement around the perforated hole. The method of claim 5, further comprising grouting the upper portion of the micro pile packer after inserting the micro pile packer into the perforated hole. The pressure micropile construction method according to claim 5, wherein an H-beam, a deformed steel bar, and a steel pipe pile are used as the reinforcing material. According to claim 5, The grouting pipe is installed so that the end is located near the bottom of the perforated hole, The air and foreign matter discharge pipe is installed so that the end is close to the lower end of the micro pile packer, the foamed urethane The injection tube is a pressure micro pile construction method using a micro pile packer, characterized in that the end is installed so as to be located between the first packing and the second packing.