KR20210087863A - Prestressed Cast in Place Concrete Pile Assembly for Retaining Wall And Method for Constructing the Same - Google Patents

Abstract

The present invention relates to a pile assembly capable of embodying a prestressed cast-in-place concrete pile (P-CIP) retaining wall construction method by applying a tensile force upward after the embedment of rebars and the placement of concrete without inserting an H-pile or a pile having a specific shape, and a construction method thereof. In accordance with the present invention, the pile assembly for a P-CIP retaining wall includes: a lower plate installed on the bottom surface of a hole drilled on the ground; an upper plate installed in an upper part of the hole drilled on the ground; a plurality of reinforcement wires having a lower part fixed to the lower plate and having an upper part fixed to the upper plate; a plurality of tension wires having a lower part fixed to the lower plate and having an upper part installed to penetrate the upper plate; a plurality of cladding materials surrounding the outside of each of the plurality of tension wires; concrete placed and cured in the hole; and a tension support means supporting the tension wires by fixing the wires to the upper plate while applying a tensile force upward to the wires after the concrete is cured.

Description

P-CIP Pile Assembly for Retaining Wall and its Construction Method {Prestressed Cast in Place Concrete Pile Assembly for Retaining Wall And Method for Constructing the Same}

The present invention relates to a pile assembly used to construct a retaining wall, and more particularly, by applying a tensile force upward after embedding reinforcing bars and pouring concrete without inserting an H pile or a specific type of pile, P-CIP (Prestressed Cast in) (P-CIP) Place concrete pile) relates to a pile assembly implementing the retaining wall construction method and its construction method.

When excavating the ground to construct an underground structure, a retaining wall is constructed to stabilize the excavated surface. The method of constructing such a retaining wall varies depending on the ground conditions and the size of the earth pressure to be supported. Among them, the CIP method is easy to construct, has good rigidity, and can be applied to most of the ground except for the rocky ground, so it is suitable for many sites. has been applied

1 shows the structure of a retaining wall constructed by the conventional CIP method, wherein the lower portion of the ground on which the retaining wall 10 is to be constructed is made of rock or the retaining wall must support a very large earth pressure. The CIP method can be applied by installing and reinforcing the H pile (I) as the thumb pile 11 at intervals.

However, since the H-pillar has a symmetrical cross-sectional shape compared to the horizontal earth pressure acting on the retaining wall, it cannot be said that the H-pillar effectively supports the earth pressure as a flexural material. In addition, during the construction of the H pile, it is difficult to install the Tremi pipe into the drilling hole because the space in the drilling hole is partitioned by the flange and web of the H pile in the process of pouring concrete after installing the H pile in the drilling hole. Therefore, since the concrete must be poured from the top of the drilling hole and poured, material separation may occur and the concrete may not be tightly filled in the drilling hole. Also, when pouring from the top, the H-pillar may be pushed to one side due to the pouring pressure.

On the other hand, centrifugal molded PC piles are also used as thumb piles in addition to the above H-files. Since the centrifugal molded PC piles are manufactured in a factory, the quality is stable. Since there is no need to pour concrete to form, the time period can be shortened. However, in some cases, it is necessary to install earth plates or shotcrete walls between thumb piles in the rock section while excavating the ground after constructing the retaining wall. While it is possible to support earth plates, etc. in the space between the flange and the web of the H file after making it exposed, when using a centrifugal molded PC pile as a thumb pile, the centrifugal molded PC pile has a circular cross-section closed by concrete. Therefore, there is a problem in that it is not easy to install the earth plate or the like because it is necessary to install an insert bolt or the like in order to install the earth plate or the shotcrete wall. In addition, it can be said that the work is relatively easy in the case of using the H pile as a thumb pile in terms of supporting the earth plate, but the work of the centrifugal molded PC pile is difficult in the work of crushing concrete to a certain depth for the installation of the earth stage. It has the problem of being cumbersome.

In order to solve this problem, in Korean Patent No. 10-1572561, in the steel assembly embedded in the concrete to be poured into the underground drilling hole in order to construct the thumb pile constituting the retaining wall, the steel assembly is a retaining wall An inner flange located on the inside of the wall, an outer flange spaced apart from the inner flange and positioned on the outside of the retaining wall, and between the inner and outer flanges as long as one end surface is joined to the inner flange to become one Disclosed is a steel assembly comprising a pair of web members and having a closed filling space inside the cross-section.

However, since the above-mentioned conventional steel assembly or H-pillar is made of long steel up and down, the price is high and there is a problem that increases the overall construction cost.

Republic of Korea Patent Registration No. 10-1572561 Republic of Korea Patent Publication No. 10-2019-0123639

The present invention is to solve the above problems, and an object of the present invention is to provide a pile assembly for a P-CIP retaining wall having a low cost, easy construction, and excellent support strength, and a construction method thereof.

Pile assembly for P-CIP retaining wall according to the present invention for achieving the above object, a lower plate installed on the bottom surface of the hole perforated in the ground; The upper plate is installed on the top of the hole perforated in the ground; a plurality of reinforcing wires having a lower end fixed to the lower plate and an upper end fixed to the upper plate; a plurality of tension wires having a lower end fixed to the lower plate and having an upper end installed to pass through the upper plate; a plurality of covering materials surrounding the outside of each of the plurality of tension wires; Concrete poured into the hole and cured; and a tensile support means for fixing and supporting the upper plate in a state in which a tensile force is applied upward to the tensile wire after the concrete is cured.

A periphery of the lower plate may be inclined upward.

The tension support means is divided into a plurality of parts that spread in the radial direction of the tension wire at the upper side of the through hole of the upper plate through which the tension wire passes, and then are retracted while the lower end is inserted into the through hole and closely contacted with the outer surface of the tension wire. Conical wedge member; and an elastic ring for supporting and applying an elastic force in a radial direction to the wedge member.

The pile assembly of the present invention may further include a support coil for supporting while simultaneously surrounding the outer sides of the upper and lower ends of the plurality of coverings.

In addition, the pile assembly of the present invention may further include an individual support coil for supporting while individually surrounding the outer side of the upper end and lower end of each of the plurality of covering materials.

According to another aspect of the present invention, one or more guide plates having different diameters are disposed between the lower plate and the upper plate, and the tension wire and the covering material pass through the hole formed in the guide plate in a zigzag form. can be installed with

According to another aspect of the present invention, the plurality of tension wires may be installed to be twisted spirally between the lower plate and the upper plate.

The pile assembly according to another aspect of the present invention may have a structure in which a reinforcing plate in the form of a long flat plate is coupled between the lower plate and the upper plate.

The construction method of the pile assembly for P-CIP retaining wall according to the present invention,

(S1) drilling a hole to a predetermined depth in the ground;

(S2) inserting an assembly in which the lower plate, the upper plate, the reinforcing wire, the tension wire, and the covering material are combined into the hole;

(S3) curing by pouring concrete into the hole; and;

(S4) after the concrete is cured, pulling the upper end of the tension wire upward and fixing the tension wire to the upper plate with a tension support means while applying a tensile force;

may include.

According to the present invention, since prestress is introduced by applying tensile force to the tensile wire after curing the concrete in the field, compressive force is applied to the upper and lower ends of the concrete, and accordingly, the compressive strength of the pile assembly and the flexural rigidity of the retaining wall are increased to increase the earth pressure resistance ability can be improved.

In addition, it is possible to reduce the construction cost because it does not use long steel materials such as steel assembly or H pile, and it can further reduce the construction cost because it can reduce the transportation cost and manufacturing cost compared to the existing factory-made pre-stress pile. There is also an easy effect.

1 is a cross-sectional view showing the structure of a retaining wall constructed by the conventional CIP method.
2 is a perspective view showing a pile assembly for a P-CIP retaining wall according to an embodiment of the present invention.
3 is a plan view of the pile assembly for the P-CIP retaining wall shown in FIG.
4 is a cross-sectional view of the pile assembly for the P-CIP retaining wall shown in FIG.
5 is a cross-sectional view of the main part of the pile assembly for the P-CIP retaining wall shown in FIG.
6 is a cross-sectional view of a pile assembly for a P-CIP retaining wall according to another embodiment of the present invention.
7 is a cross-sectional view of a pile assembly for a P-CIP retaining wall according to another embodiment of the present invention.
8 is a cross-sectional view of a pile assembly for a P-CIP retaining wall according to another embodiment of the present invention.
9 is a cross-sectional view of a pile assembly for a P-CIP retaining wall according to another embodiment of the present invention.
10 is a cross-sectional view of a pile assembly for a P-CIP retaining wall according to another embodiment of the present invention.
11 is a perspective view of a pile assembly for a P-CIP retaining wall according to another embodiment of the present invention.
12 is a cross-sectional view of the pile assembly for the P-CIP retaining wall shown in FIG.
13 is a plan view and an enlarged perspective view of a portion of a pile assembly for a P-CIP retaining wall according to another embodiment of the present invention.

The configuration shown in the embodiments and drawings described in this specification is only a preferred example of the disclosed invention, and there may be various modifications that can replace the embodiments and drawings of the present specification at the time of filing of the present application.

Hereinafter, a pile assembly for a P-CIP retaining wall and a construction method thereof will be described in detail according to the embodiments described below with reference to the accompanying drawings. In the drawings, like reference numerals denote like elements.

2 to 5, the P-CIP retaining wall pile assembly according to an embodiment of the present invention is a lower plate 110 installed on the bottom surface of a hole (H) perforated in the ground, perforated in the ground An upper plate 120 installed at the upper end of the hole H, a plurality of reinforcing wires 130 having a lower end fixed to the lower plate 110 and an upper end fixed to the upper plate 120, and a lower end fixed to the lower plate A plurality of tension wires 140 fixed to 110 and installed so that an upper end passes through the upper plate 120 , a plurality of covering materials 150 surrounding the outside of each of the plurality of tension wires 140 , and the hole (H) The concrete 160 that is poured inside and cured, and the tensile force is applied to the upper plate 120 after the concrete 160 is cured and the tensile force is applied upward to the upper plate 120. support means.

The lower plate 110 , the upper plate 120 , the reinforcing wire 130 , the tension wire 140 , and the covering material 150 are pre-coupled and assembled before being installed inside the hole H, and then inside the hole H. inserted and installed. At this time, the tension wire 140 is coupled to the lower plate 110 and the upper plate 120 in a state in which no tensile force is applied.

The lower plate 110 is seated on the bottom surface of the hole (H) to form the lower end of the pile assembly. The lower plate 110 is made of a steel material in the form of a circular ring having an opening in the center, and a plurality of coupling holes 111 to which the lower end of the tension wire 140 is coupled are formed at regular intervals along the circumferential direction. .

It is preferable that the periphery of the lower plate 110 is inclined upward, which is the compression force applied to the concrete 160 at the periphery of the lower plate 110 when the tension wire 140 is pulled upward to generate a tensile force. This is because the tensile wire 140 may be relatively small compared to the inner portion to which it is coupled. That is, when the periphery of the lower plate 110 is inclined upward while going radially outward, when a tensile force is applied from the tension wire 140, the periphery of the lower plate 110 radially inwardly of the concrete 160. Compressive force is applied to the periphery, so that a uniform compressive force is applied to the entire concrete 160 to further increase the compressive strength and the flexural rigidity of the retaining wall, thereby improving the resistance to earth pressure.

The upper plate 120 is made of a steel material in the form of a circular ring having an opening in the center, and is disposed at the top of the hole H to be in close contact with the upper surface of the concrete 160 . The peripheral portion of the upper plate 120 may also be formed in a shape inclined downward while going outward in the radial direction to correspond to the peripheral portion of the lower plate 110 .

The reinforcing wire 130 may be configured using conventional reinforcing bars, and a plurality of linear reinforcing wires 131 each of which is welded to the lower plate 110 and the upper plate 120 and fixed to the lower end and upper end thereof; It may be composed of a plurality of circular reinforcing wires 132 coupled to surround the plurality of linear reinforcing wires 131 at the same time. A plurality of the circular reinforcing wire 132 may be arranged to be spaced apart in the vertical direction, and may be fixed to the linear reinforcing wire 131 by welding.

The tension wire 140 is for introducing prestress to the column of the concrete 160 by pulling upward after curing the concrete 160, and a strand made by twisting several strands of steel wire may be applied. . A plurality of the tension wires 140 are arranged at regular intervals along the lower plate 110 and the upper plate 120 in the circumferential direction. The lower end of the tension wire 140 is firmly fixed to the lower plate 110 by the fastening member 175 . The fastening member 175 may be configured by applying a conventional strand fixing device, or may be configured by applying the same or similar tensile support means as shown in FIG. 5 .

Since the tensile wire 140 is pulled after curing of the concrete 160 and a tensile force is applied, the outer surface of the tensile wire 140 between the lower plate 110 and the upper plate 120 is covered with a covering material 150 . The covering material 150 may be configured using a hose or tube made of a flexible resin.

The upper end of the tension wire 140 protrudes toward the upper side of the upper plate 120 through the through hole 121 formed in the upper plate 120, and is pulled by a tensile force adding device such as a hydraulic jack to apply a tensile force. It is fixed and supported on the upper plate 120 by the support means.

The tension support means is opened and closed in the radial direction of the tension wire 140 above the through hole 121 of the upper plate 120 through which the tension wire 140 passes, and the lower end of the through hole 121 is closed. ) inserted into the conical wedge member 171 for fixing the tension wire 140 while being in close contact with the outer surface of the tension wire 140, and an elastic ring supporting the wedge member 171 by applying an elastic force inward in the radial direction ( 172).

The wedge member 171 has a conical shape divided into two or three, and has a structure in which a ratchet protrusion or a toothed protrusion of a predetermined shape is formed to protrude from the inner surface in order to prevent the tension wire 140 from slipping.

The pile assembly for P-CIP retaining wall having such a configuration is constructed as follows.

First, a hole (H) is drilled to a predetermined depth in the ground.

Then, the assembly in which the lower plate 110, the upper plate 120, the reinforcing wire 130, the tension wire 140, and the covering material 150 are combined is inserted into the hole H.

Then, the concrete 160 is poured into the hole (H) and cured.

When the curing of the concrete 160 is completed, the upper end of the tensile wire 140 protruding upward of the upper plate 120 is pulled upward using a tensile force applying device such as a hydraulic jack, and tensile force is applied while the tensile force is applied. The wedge member 171 of the means is inserted into the through hole 121 to fix the tension wire 140 to the upper plate 120 .

As such, when a tensile force is applied to the tensile wire 140 and prestress is introduced, a compressive force is applied to the upper end and lower end of the concrete 160, and the compressive strength and flexural rigidity of the retaining wall can be increased to improve the resistance to earth pressure. have.

When the retaining wall in which a plurality of pile assemblies are continuous on the ground is completed through this series of construction processes, a wale and a brace or an earth anchor are installed in the pile assembly.

Meanwhile, in the above-described embodiment, the tension wire 140 and the covering material 150 are both installed vertically, but as shown in FIG. 6 , between the lower plate 110 and the upper plate 120, each having a different diameter At least one guide plate 180 is disposed, and the tension wire 140 and the covering material 150 are formed in a zigzag form so that the tension wire 140 and the covering material 150 pass through the hole formed in the guide plate 180 . can also be installed as

In this case, tensile force is applied not only in the longitudinal direction but also in the transverse direction, so that the compressive force is applied to the concrete 160 in the longitudinal and transverse directions to further improve mechanical performance (compressive strength and flexural rigidity of the retaining wall).

Alternatively, as shown in FIG. 7 , the lower end of the tension wire 140 is connected to any one coupling hole 111 of the lower plate 110 , and the upper end of the tension wire 140 penetrates the upper plate 120 . Among the balls 121 , the through-holes 121 having a predetermined phase difference from the coupling holes 111 of the lower plate 110 are passed through the plurality of tension wires 140 to the lower plate 110 and the upper plate. It may be installed to be twisted in a spiral between 120 .

In addition, in order to further increase the strength reinforcement by the tensile wire 140, as shown in FIG. 8, a support coil 191 for supporting while simultaneously surrounding and supporting the outer sides of the upper and lower ends of the plurality of coverings 150 is additionally installed or , as shown in FIG. 9 , the individual support coils 192 may individually surround and support the outside of the upper end and lower end of each of the plurality of covering materials 150 .

Also, between the lower plate 110 and the upper plate 120, a reinforcing plate 135 in the form of a long flat plate is welded to the reinforcing wire 130 and/or the lower plate 110 and the upper plate 120 by welding. In addition to reinforcing the strength, it is possible to facilitate the connection with the supporting structure (eg, wale and brace) after the construction of the retaining wall.

On the other hand, in the first embodiment described above, the lower end of the linear reinforcing wire 131 constituting the reinforcing wire 130 is fixed to the lower plate 110, but as shown in FIGS. 11 and 12, linear reinforcement as necessary. The wire rod 130 may be installed to extend to the lower side of the lower plate 110 by a predetermined depth.

13 shows another embodiment of the present invention, the pile assembly of this embodiment is provided with a long hole type mount guide hole 125 extending radially to the upper plate 120, the mount guide hole 125 ) has a configuration in which a wedge mount member 173 into which a conical wedge member 171 for fixing the tension wire 140 is inserted is installed.

The wedge mount member 173 is in the form of a cylindrical tube penetrating up and down, and is supported while the wedge member 171 is inserted through the hole at the top of the wedge mount member 173, so that the wedge member 171 is the tension wire 140. It acts to stably fix the top. The lower end of the wedge mount member 173 is movable in the radial direction of the upper plate 120 along the mount guide hole 125 so that the position at which the wedge member 171 fixes the tension wire 140 can be adjusted. have.

In the above, the present invention has been described in detail with reference to the embodiments, but those of ordinary skill in the art to which the present invention pertains may make various substitutions, additions and modifications within the scope not departing from the technical spirit described above. Of course, it should be understood that such modified embodiments also fall within the protection scope of the present invention as defined by the appended claims below.

H: Hall 110: lower plate
111: coupling hole 120: upper plate
121: through hole 125: mount guide hole
130: reinforcing wire 131: linear reinforcing wire
132: circular reinforcing wire 135: reinforcing plate
140: tension wire rod 150: covering material
160: concrete 171: wedge member
172: elastic ring 173: wedge mount member
175: fastening member 180: guide plate
191: support coil 192: individual support coil

Claims (7)

a lower plate installed on the bottom surface of the hole perforated in the ground;
The upper plate is installed on the top of the hole perforated in the ground;
a plurality of reinforcing wires having a lower end fixed to the lower plate and an upper end fixed to the upper plate;
a plurality of tension wires having a lower end fixed to the lower plate and having an upper end installed to pass through the upper plate;
a plurality of covering materials surrounding the outside of each of the plurality of tension wires;
Concrete poured into the hole and cured; and;
Tensile support means for fixing and supporting the upper plate in a state in which a tensile force is applied upward to the tensile wire after the concrete is cured;
including,
The periphery of the lower plate is formed to be inclined upwardly P-CIP retaining wall pile assembly. According to claim 1, wherein the tension support means, the lower end is inserted into the through hole while extending in the radial direction of the tension wire on the upper side of the through hole of the upper plate through which the tension wire passes, and the outer surface of the tension wire and the tension wire rod. a wedge member of a conical shape divided into a plurality to be in close contact; And P-CIP retaining wall pile assembly including an elastic ring for supporting and applying an elastic force in the radial direction to the wedge member. The pile assembly for a P-CIP retaining wall according to claim 1, further comprising a support coil supporting while simultaneously enclosing the outer sides of the upper and lower ends of the plurality of coverings. The pile assembly for a P-CIP retaining wall according to claim 1, further comprising an individual support coil supporting the outer side of the upper end and lower end of each of the plurality of covering materials while individually surrounding and supporting the outer side. The pile assembly for a P-CIP retaining wall according to claim 1, wherein the plurality of tension wires are installed to be twisted spirally between the lower plate and the upper plate. The pile assembly for a P-CIP retaining wall according to claim 1, wherein a reinforcing plate in the form of a long flat plate is coupled between the lower plate and the upper plate. As a construction method of the pile assembly for P-CIP retaining wall according to any one of claims 1 to 6,
(S1) drilling a hole to a predetermined depth in the ground;
(S2) inserting an assembly in which the lower plate, the upper plate, the reinforcing wire, the tension wire, and the covering material are combined into the hole;
(S3) curing by pouring concrete into the hole; and;
(S4) after the concrete is cured, pulling the upper end of the tension wire upward and fixing the tension wire to the upper plate with a tension support means while applying a tensile force;
A method of constructing a pile assembly for a P-CIP retaining wall comprising a.

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