KR102384199B1 - Prestressed soldier H-pile and self-supporting retaining wall construction method using the same - Google Patents

Abstract

The present invention relates to a prestressed H-pile being under bending stress by compressive tension, and a self-supporting retaining wall construction method using the same. The prestressed H-pile comprises: a main member having an H-beam structure; an upper fixing member and a lower fixing member fixed to a front flange located on a front side of an excavated part among two flanges located at both ends of the main member and constituting the main member; an auxiliary member having an H-beam structure and positioned between the upper fixing member and the lower fixing member; coupling nuts and coupling bolts for temporarily fastening the flanges of the auxiliary member and the main member so that the flange of the auxiliary member and the front flange of the main member can slide with each other while being in close contact with each other; and a tension jack located between the upper fixing member and the auxiliary member to maintain the compressive tension applied to a lower part of the upper fixing member and an upper part of the auxiliary member by using a hydraulic jack to introduce bending stress to the main member. Therefore, the prestressed H-pile can minimize the displacement of a retaining wall supported by the H-pile, thereby enabling the retaining wall to be supported by itself.

Description

Prestressed thumb pile and self-supporting retaining method using the same {Prestressed soldier H-pile and self-supporting retaining wall construction method using the same}

The present invention relates to a thumb pile to which prestress of bending stress is introduced using compressive tension force and a self-supporting retaining method using the same, and more particularly, to a main member of an H-beam structure, two flanges located at both ends of the main member and constituting the main member. ), the upper and lower fixing members fixed to the front flange located on the front side of the excavation part, the auxiliary member of the H-beam structure located between the upper fixing member and the lower fixing member, and the flange of the auxiliary member are in close contact with the front flange of the main member The coupling nut and coupling bolt that temporarily fastens the flanges of the auxiliary member and the main member so that they can slide to each other in a state where the upper fixing member and the auxiliary member are located between the upper fixing member and the auxiliary member, and using a hydraulic jack to introduce bending stress to the main member, the lower part of the upper fixing member and the auxiliary member A thumb pile to which prestress of bending stress is introduced, characterized in that it includes a tension jack for maintaining the compressive tension applied to the upper part, and it is inserted into a drilling hole drilled to a depth where horizontal displacement does not occur during ground excavation and drilled After embedding high-quality soil in the hole, compressive tension is applied to the upper and lower fixing members and auxiliary members using a hydraulic device to introduce a prestress of bending stress to the main member of the thumb pile. The present invention relates to a thumb pile to which a prestress of bending stress that can support earth pressure only with a retaining wall without a support member by reducing the deformation of the thumb pile is introduced, and a self-supporting retaining method using the same.

When excavating the ground for the construction of underground structures, support members such as horizontal struts, rakers, and earth anchors are widely used to minimize displacement of retaining walls due to earth pressure. Horizontal braces and rakers are difficult to apply when the excavation area of the site is large because their length is too long. Do.

In order to solve this problem, in Korean Patent Application Laid-Open No. 10-2019-0036591, as shown in FIG. 1 , an upper fixing device and a lower fixing device installed on the rear flange located on the rear side of the excavation unit at both ends of the H-beam, and the upper and lower fixings The thumb pile, which is composed of a tension member coupled to the device, and a fixing nut installed at both ends of the tension member to fix the tension member to the upper and lower fixing devices, is inserted into the drilled hole at the boundary of the excavation part, and tensile tension is applied to the tension member with a hydraulic jack to H A self-supporting type that can safely support earth pressure only with the retaining wall without supporting members by reducing the flexural deformation of the H-beam that supports the retaining wall by reducing the stress generated on the H-beam by earth pressure by introducing pre-stress of compression and bending stress to the beam. Developed a retaining method. However, in the previous application technique, the second moment of the cross section of the thumb pile was not maximized compared to the size of the drilling hole by using a round steel bar with a small cross section as a tension material to introduce prestress to the H beam, so the bending deformation of the H beam due to earth pressure was prevented. There is a limit to restraint, and in the end, it has the disadvantage that the displacement of the retaining wall supported by the H-beam cannot be suppressed as much as possible.

In addition, the Republic of Korea Patent Publication No. 1609805, "Thumb piles with pre-stress introduced and self-supporting temporary retaining construction method using the same" introduces pre-stress of compressive bending stress to increase compression capacity primarily at a certain length of the rear part of the excavation of the H-beam. After manufacturing the pile and inserting the thumb pile into the drilling hole, the prestress of the compression bending stress is introduced secondarily to the rear part of the thumb pile to secure the required compressive force. A self-supporting temporary retaining wall construction method that minimizes the displacement of the retaining wall was proposed.

However, the invention registered as above also introduces a pre-stress of bending stress to the thumb pile by applying a tensile force to the steel bar with a small cross-sectional area installed on the rear part of the thumb pile, similar to Patent Publication No. 10-2019-0036591. There was a structural limitation in maximizing the displacement of the retaining wall supported by the thumb pile as it could not maximize the flexural rigidity of the pile.

Republic of Korea Patent Publication No. 10-2019-0036591 (published on 04. 05. 2019) Republic of Korea Patent Publication No. 1609805 (registered on March 31, 2016)

Accordingly, it was made in consideration of the various problems of the prior art as described above, and an object of the present invention is to introduce a prestress of bending stress to the main member of the H-beam structure pre-fastened with the auxiliary member by applying a compressive tension to the auxiliary member of the H-beam structure. Therefore, it is to provide a self-supporting retaining wall that can stand on its own without a support member by reducing the stress generated in the thumb pile by the earth pressure during excavation of the ground and minimizing the displacement of the retaining wall by suppressing the bending deformation of the thumb pile due to the earth pressure.

In addition, the present invention is an auxiliary member used to introduce a prestress of bending stress to the main member, and by using an H-beam with a large cross-sectional second moment to increase the flexural rigidity of the thumb pile, the bending deformation of the thumb pile due to earth pressure is minimized, and thereby An object of the present invention is to provide a self-supporting retaining wall that can minimize the displacement of the retaining wall.

In addition, in the present invention, since the auxiliary member is pre-fastened to the main member by a coupling nut and coupling bolt, even if the auxiliary member has a smaller cross-sectional area than the main member, buckling by the compressive tension force or earth pressure applied by the hydraulic jack is prevented. It is to provide a self-supporting retaining wall with high stability.

In addition, the present invention is a method of removing the hydraulic jack while maintaining the compressive tension with the tension jack after applying the compression tension to the auxiliary member with a detachable hydraulic jack. Since the prestress of the bending stress is introduced to the thumb pile, the hydraulic jack can be repeatedly used for other thumb piles. It is to provide a self-supporting retaining wall having excellent economic efficiency and excellent workability that can control the displacement of the retaining wall by easily adjusting the size of the prestress introduced to the thumb pile through reinstallation and reloading of the hydraulic jack during ground excavation.

The thumb pile to which the prestress of the bending stress is introduced according to the present invention for achieving the above object is an H-beam structure that supports the earth pressure acting on the rear surface of the excavation part, and a bolt hole is located at a predetermined position of the front flange located on the front side of the excavation part. This plurality of perforated main member, the auxiliary member of the H-beam structure in which a bolt hole corresponding to the bolt hole perforated in the front flange of the main member is perforated in the flange, the upper fixing member fixed to the front flange of the upper end of the main member, the lower end of the main member a lower fixing member fixed to the front flange of It is characterized in that after applying the compressive tension to the auxiliary member with the hydraulic jack installed between the auxiliary members, the compression tension applied to the upper and lower fixing members and the auxiliary member is maintained with the tension jack installed between the upper fixing member and the auxiliary member.

In addition, in the present invention, the lower end of the upper fixing member is blocked by a lower central end plate, the upper end of the lower fixing member is blocked by an upper end plate, and the upper and lower ends of the auxiliary member are blocked by an upper central end plate and a lower end plate, respectively characterized.

In addition, in the present invention, in a state in which the bolt hole punched in the flange of the auxiliary member is tentatively fastened with the main member by the coupling nut and the coupling bolt, the auxiliary member moves downward with respect to the main member by the compressive tension force to the compressive force of the hydraulic jack. It is characterized in that it is formed in an oval shape to be possible.

In addition, the present invention is characterized in that the main member and the upper fixing member, or the main member and the lower fixing member are fastened with a coupling nut and a coupling bolt.

In addition, the present invention is characterized in that the lower central end plate and the lower side end plate connected from the side are integrally coupled to the reinforcing rib and the back plate.

In addition, the present invention is characterized in that the upper central end plate and the upper side end plate connected from the side are integrally combined with the reinforcing rib and the back plate.

In addition, the present invention is the auxiliary member 20 and the main member 10 by coupling and fixing the gap maintaining rod 90 having a predetermined diameter and having a length equal to the flange width to the rear flanges of both ends of the auxiliary member 20 by welding or the like. ) is characterized in that it maintains a certain interval.

In addition, the self-supporting retaining method using the thumb pile to which the present invention prestress is introduced is a step of forming a drilling hole to a depth at which horizontal displacement will not occur due to earth pressure while the ground is excavated at the ground excavation interface, the main member, the lower part is the lower part The thumb pile consisting of an upper fixing member blocked by an extension end plate, a lower anchoring member, an auxiliary member having the upper end blocked by an upper extension end plate, and a tension jack are pushed so that the tension jack protrudes above the drilling hole, and the auxiliary member faces the front of the excavation part After inserting high-quality soil into the drilling hole, hydraulic jacks are installed on both sides of the tension jack, and a predetermined compressive tension is applied to the lower part of the upper fixing member and the upper part of the auxiliary member. Maintaining pre-stress of tensile and bending stress introduced to the main member by rotating the screw shaft using a handle to contact the spherical groove of the upper plate coupled to the It is characterized in that the retaining wall supported by the thumb pile during excavation of the ground consists of a step of supporting the earth pressure and standing on its own.

In addition, the self-supporting retaining method using the thumb pile to which the present invention prestress is introduced is a step of forming a drilling hole using a casing to a depth at which horizontal displacement will not occur due to earth pressure while the ground is excavated at the ground excavation interface, the main member , the upper fixing member with the lower end blocked by the lower central end plate, the auxiliary member with the upper end blocked by the upper central end plate, and the thumb pile consisting of the tension jack, the auxiliary member faces the front of the excavation part while the tension jack protrudes above the drilling hole Inserting it into the drilling hole to make it so that it is inserted into the drilling hole, pulling out and removing the casing after embedding high-quality soil in the drilling hole, coupling the lower side end plates to both sides of the lower central end plate, and the upper side on both sides of the upper central end plate In the step of combining the single plate, hydraulic jacks are installed on both sides of the tension jack, and a predetermined compressive tension is applied to the lower part of the upper fixing member and the upper part of the auxiliary member. Rotating the screw shaft to maintain prestress of tensile stress and bending stress introduced to the main member, removing the hydraulic jack used for introducing compressive tension, lower side end plate and upper side end plate coupled to the side of the lower central end plate and upper central end plate It is characterized in that it consists of a step of separating and removing, and the retaining wall supported by a thumb pile while excavating the ground to be excavated in front of the main member supports the earth pressure and becomes self-supporting.

According to the present invention, the displacement of the retaining wall supported by the thumb pile by reducing the bending deformation by reducing the stress generated in the thumb pile by the earth pressure by introducing a pre-stress of the bending stress to the thumb pile by applying a compressive tension force to the auxiliary member. It has the effect of making it possible to become self-reliant by minimizing the

In addition, the present invention is an auxiliary member used to introduce the prestress of the bending stress to the main member, and by using the H-beam having a large cross-sectional second moment, the bending rigidity of the thumb pile is increased, and the bending deformation of the thumb pile due to earth pressure can be minimized. It has the effect that it can be applied to the deep excavation depth.

In addition, in the present invention, since the auxiliary member is pre-fastened to the main member by the coupling nut and coupling bolt, even if the auxiliary member has a smaller cross-sectional area than the main member, it is prevented from being buckled by the compressive tension force applied by the hydraulic jack or the bending force due to the earth pressure. It has the effect of increasing the structural stability of

In addition, since the present invention uses a detachable hydraulic jack to apply compressive tension to the auxiliary member of the thumb pile, the same hydraulic jack can be repeatedly used for a plurality of thumb piles, thereby having an economical effect.

In addition, during excavation of the ground, the horizontal displacement of the retaining wall can be minimized by reinstalling the removable hydraulic jack and adjusting the size of the compressive tension to adjust the size of the prestress introduced to the thumb pile, thereby increasing the structural safety of the retaining wall.

1 is a state diagram of a conventional thumb pile
Figure 2 is a cross-sectional view of an embodiment of the present invention thumb peg
3 is a cross-sectional view of the tension jack applied to the present invention;
Figure 4 is an embodiment installation cross-sectional view of the present invention thumb pile
5 is a cross-sectional view in which a gap maintaining rod is installed in an embodiment of the thumb pile of the present invention;
Figure 6 is a perspective view of one embodiment of the present invention thumb stakes
7 is a perspective view in which a tension jack is installed in an embodiment of the thumb pile of the present invention;
8 is a perspective view in which a tension jack and a hydraulic jack are installed in an embodiment of the thumb pile of the present invention;
Figure 9 is a state diagram showing the step of introducing a pre-stress to the thumb pile with a tension jack and a hydraulic jack in one embodiment of the present invention
10 is a state diagram of compressive and tensile stresses generally generated in thumb piles by earth pressure;
11 is a state diagram of compression and tensile stress generated in the main member constituting the thumb pile of the present invention by earth pressure;
12 is a comparative cross-sectional view of a conventional thumb pile and a thumb pile of the present invention;
13 is an exploded perspective view of another embodiment of the thumb pile of the present invention;
Figure 14 is a perspective view of another embodiment combined of the thumb pile of the present invention;

Hereinafter, the present invention will be described in detail based on the accompanying drawings. Figure 2 is a cross-sectional view of one embodiment of the present invention thumb pile, Figure 3 is a cross-sectional view of the tension jack applied to the present invention.

First, the thumb pile to which the prestress of the present invention is introduced has an H-beam structure that supports the earth pressure acting on the rear surface of the excavation part, and a plurality of bolt holes 11 are drilled at certain positions of the front flange located on the front side of the excavation part. main member 10, the auxiliary member 20 of the H-beam structure in which the bolt hole 21 corresponding to the bolt hole 11 perforated in the front flange of the main member 10 is perforated in the flange, the main member 10 The upper fixing member 30 fixed to the front flange of the upper end, the lower fixing member 40 fixed to the front flange of the lower end of the main member 10, and the auxiliary member 20 are in close contact with the front flange of the main member 10 A coupling nut 70 and a coupling bolt 80 that are pre-fastened to the bolt holes 11 and 21 formed in the main member 10 and the auxiliary member 20 so as to be slid in the state, and as shown in FIGS. 7 and 8. Similarly, after applying a compressive tension to the auxiliary member 20 with the hydraulic jack 60 installed between the upper fixing member 30 and the auxiliary member 20, the upper and lower fixing members 30 and 40 and the auxiliary member 20 It is characterized in that it maintains the compression tension applied to the tension jack (50) installed between the upper fixing member (30) and the auxiliary member (20).

In the present invention, the compressive tension applied to the auxiliary member 20 of the H-beam structure is eventually transferred to the upper and lower fixing members 30 and 40 to induce prestresses of tensile stress and bending stress in the main member 10, and thus the main member 10 ), a self-supporting retainer that can become self-reliant without a support member by reducing the amount of stress generated in the thumb pile due to earth pressure during excavation of the ground and suppressing the bending deformation of the thumb pile due to earth pressure to minimize the displacement of the retaining wall. provide a wall.

The present invention is an auxiliary member (20) used to introduce a prestress of bending stress to the main member (10), and by using an H-beam with a large cross-sectional secondary moment to increase the flexural rigidity of the thumb pile, the bending deformation of the thumb pile due to earth pressure Because it is minimized, it provides a self-supporting retaining wall that can be applied even in a deep excavation depth of the ground.

Since the present invention uses a detachable hydraulic jack 60 to introduce the prestress of bending stress to the thumb piles, the same hydraulic jack 60 is used for a plurality of thumb piles to reduce the construction cost, and to reinstall and reload the hydraulic jack during excavation of the ground It provides a self-supporting retaining wall with excellent workability that can control the displacement of the retaining wall by adjusting the size of the prestress introduced to the thumb pile through the

In the present invention, the lower end of the upper fixing member 30 is blocked with a lower extended end plate 32 or a lower central end plate 32a', and the upper end of the lower fixing member 40 is blocked with an upper end plate 42, and the auxiliary The upper end and lower end of the member 20 are blocked by the upper end plate 22 and the lower end plate 25, respectively, or are blocked by the upper central end plate 22a' and the lower end plate 25, which are the upper fixing member 30 It not only facilitates the installation of the tension jack 50 and the hydraulic jack 60 between the lower end of the and the upper end of the auxiliary member 20, but also applies the compressive tension force applied by the hydraulic jack 60 to the upper fixing member 30 and the auxiliary member. (20), so that the compression tension applied to the upper and lower fixing members 30 and 40 and the auxiliary member 20 by using the tension jack 60 can be stably transmitted to the lower fixing member 40 to do

3 is a cross-sectional view of the tension jack applied to the present invention, wherein the tension jack 50 is screwed to the screw thread of the holder 53 and the holder 53 having a thread on the inner surface while being fixed to the upper surface of the central part of the lower plate 52, and A handle 55 is formed in the middle portion so that the length can be adjusted through rotation, and the upper part is coupled to the screw shaft 54 having a spherical cross section, the upper fixing member 30, and the lower part is the screw shaft 54 upper part. It is composed of an upper plate 51 having a spherical groove 56 coupled to the sphere of the .

The upper plate 51 and the lower plate 52 of the tension jack 50 are the lower extended end plate 32 or the lower central end plate 32a ′ and the upper end of the auxiliary member 20 installed at the lower end of the upper fixing member 30 , respectively. It is coupled to the upper extended end plate 22 or the upper central end plate 22a ′ installed in a coupling nut 70 and a coupling bolt 80 .

At this time, the tension jack 50, which serves to maintain the compressive tension applied by the hydraulic jack, is adjustable in length like a screw jack, etc. Any device capable of maintaining compressive tension can be substituted.

4 is a cross-sectional view of an embodiment of the thumb pile of the present invention, wherein the bolt hole 21 punched in the flange of the auxiliary member 20 is the auxiliary member 20 by the coupling nut 70 and the coupling bolt 80. In a state of being pre-fastened to and in close contact with the main member 10 , it is minutely moved downward by the compression tension force of the hydraulic jack 60 to form an oval shape so that the compression tension force can be properly transmitted to the lower fixing member 40 .

In addition, although the drilling hole is not specifically illustrated in the present invention, in order to install the thumb pile, of course, the drilling hole is drilled in the ground with an auger screw or the like, and FIG. 4 shows that the thumb pile of the present invention is installed in the drilling hole. Earth pressure applied from the rear side is applied to the thumb pile, and accordingly, in the main member 10 of the H-beam structure constituting the thumb pile, a compressive stress is generated in the front flange and a tensile stress is generated in the rear flange. Unlike the conventional idea described above, the present invention applies a compressive tension force to the main member ( 10) Since prestress of tensile stress is introduced in the entire area and prestress of tensile stress and compressive stress are introduced respectively to the front flange and rear flange of the main member 10, the stress generated in the main member 10 by the earth pressure is offset. It is to reduce the bending deformation of the thumb pile and the displacement of the retaining wall supported by the thumb pile.

5 is a cross-sectional view in which a spacing rod is installed in an embodiment of the thumb pile of the present invention, and a spacing rod 90 having a predetermined diameter and having a length equal to the flange width on the rear flanges of both ends of the auxiliary member 20 is welded, etc. The auxiliary member 20 and the main member 10 are maintained at a certain distance by coupling and fixing with a . This is due to the fact that the auxiliary member 20 and the main member 10 are spaced apart at regular intervals by the spacing rod 90 even when bending occurs due to the compression tension force by the hydraulic jack 60 being applied to the main member 10. Accordingly, the bending load introduced into the main member 10 by the tension and compressive force applied to the auxiliary member 20 is easily transmitted over the entire length of the main member 10, thereby providing a larger size to the main member 10. It is designed to introduce bending stress prestress.

Figure 6 is a perspective view of one embodiment of the thumb pile of the present invention, Figure 7 is a perspective view in which a tension jack is installed in an embodiment of the thumb pile of the present invention, Figure 8 is a tension jack and a hydraulic jack in an embodiment of the present invention thumb pile It is a perspective view installed together, and FIG. 9 is a state diagram showing the step of introducing the prestress of the bending stress to the main member 10 by a tension jack and a hydraulic jack in an embodiment of the thumb pile of the present invention.

Figure 6 is a perspective view of an embodiment of the thumb pile of the present invention, showing before the tension jack 50 is installed on the thumb pile, Figure 7 is a perspective view of the tension jack 50 installed on the thumb pile of the present invention. After the jack 50 is installed by the method described in FIG. 3 above, as shown in FIG. 8, when the hydraulic jacks 60 are installed in a balanced manner on the left and right sides of the tension member 50, preparation to apply the compression tension to the auxiliary member 20 is completed , this step corresponds to Fig. 9 (a). Next, (b) of FIG. 9 shows the lower end of the upper fixing member 30 and the upper end of the auxiliary member 20 by increasing the length of the hydraulic jack installed between the upper end of the auxiliary member 20 and the lower end of the upper fixing member 30 . As the required compressive tension is applied to the When the compression tension of the tension is transferred to the lower fixing member 40, the screw shaft 54 of the tension jack 50 is rotated using a handle as shown in FIG. ) in the state of maintaining the compressive tension applied to the auxiliary member 20 and the upper and lower fixing members 30 and 40 by seating it in line with the spherical groove 56 of the upper plate 51, finally in FIG. 9 (d) By removing the hydraulic jacks 60 installed on the left and right of the tension jack 50 as shown, the introduction of the prestress of the bending stress to the main member 10 of the thumb pile is completed.

10 is a state diagram of compression and tensile stress generated in a thumb pile of an H-beam structure due to earth pressure in general, and FIG. 12 is a comparative cross-sectional view for comparing the cross-sectional secondary moment of the conventional thumb pile and the present invention thumb pile.

As shown in Fig. 10, when horizontal earth pressure is applied to the H-beam widely used as a thumb pile, the H-beam is bent in the form of a cantilever, and a compressive stress (+) is applied to the front flange located on the front side of the excavation part. and tensile stress (-) is applied to the rear flange located on the rear side of the excavation part.

11 is a state diagram of compression and tensile stress occurring in the main member 10 constituting the thumb pile to which the prestress of the present invention is introduced by the horizontal earth pressure. Compressive stress (+) and tensile stress (-) are generated on the front flange and rear flange of the side, respectively. As a result, a tensile stress (-) acts on the entire area of the main member 10” and at the same time “the compressive tension applied to the auxiliary member 20 is transmitted to the upper and lower fixing members 30 and 40, so that the bending load on the main member 10 is applied. As this is applied, a tensile stress (-) is generated on the front flange of the front side of the excavation part and a compressive stress (+) is generated on the rear flange of the rear side of the excavation part. As the compressive stress (+) generated in the front flange of the main member 10 and the tensile stress (-) generated in the rear flange of the main member 10 are significantly reduced by the prestress of the bending stress introduced into the main member 10 by the auxiliary member, the earth pressure It can be seen that the bending deformation of the thumb pile is reduced.

12 is a comparative cross-sectional view comparing the cross-section of a member affecting the cross-sectional secondary moment of a conventional thumb pile and a thumb pile of the present invention. Prestress is applied to the thumb pile by applying a tensile tension to the thumb pile, and Fig. 12 (b) shows a compressive tension to the H-beam-shaped auxiliary member 20 that is pre-fastened to the main member 10 of the thumb pile of the present invention. By applying a prestress of bending stress to the main member 10, as shown in the figure, the thumb pile of the present invention to which an H-beam-shaped auxiliary member 20 installed in the same drilling hole is applied has a cross-sectional secondary moment than that of a conventional thumb pile. It can be seen that the flexural rigidity is increased, and as a result, the bending deformation of the thumb pile due to the horizontal earth pressure is reduced, and the horizontal displacement of the retaining wall is reduced.

13 is an exploded perspective view of another embodiment of the thumb pile of the present invention, and FIG. 14 is a combined perspective view of another embodiment of the thumb pile of the present invention, wherein the lower end of the upper fixing member 30 is closed with a lower central end plate 32a' The upper end of the member 20 is blocked by an upper central end plate 22a', and the lower side end plate 32b' connected from the lower central end plate 32a' and coupled from the side is a reinforcing rib 33' and a back plate 34'. ) and the upper central end plate 22a ′ and the upper side end plate 22b ′ connected from the side are integrally coupled with the reinforcing rib 23 ′ and the back plate 24 ′, and the upper side end plate (22b') and the lower side end plate (32b') are necessary only when using the hydraulic jack 60 to apply a compressive tension to the auxiliary member 20, and after removing the hydraulic jack 60, it is not necessary, so the hydraulic jack 60 ), after removing the hydraulic jack 60 while being used as a support plate for supporting it, the upper side end plate 22b' and the lower side end plate 32b' are removed and reused in another thumb pile, so that the member can be economically utilized.

In the case of applying the self-supporting retaining method using the thumb pile to which the present invention prestress is introduced, the ground on which the drilling hole is formed is hard, so that the casing is not used when the drilling hole is formed. (32) is installed, the self-supporting retaining method using the thumb stakes in which the upper extended end plate 22 is installed on the upper end of the auxiliary member 20 is made in the following steps.

a) forming a drilling hole to a depth at which horizontal displacement does not occur due to earth pressure while the ground is excavated at the ground excavation interface;

b) the main member 10, the upper fixing member 30 whose lower end is closed with the lower extended end plate 32, the lower fixed member 40, the auxiliary member 20 whose upper end is closed with the upper extended end plate 22, tension Inserting the thumb pile composed of the jack 50 into the drilling hole with the auxiliary member 20 facing the front of the excavation part while the tension jack 50 protrudes above the drilling hole;

c) After filling the drilling hole with good quality soil, hydraulic jacks 60 are installed on both sides of the tension jack 50, and a predetermined compressive tension is applied to the lower part of the upper fixing member 20 and the upper part of the auxiliary member 20, and then the screw shaft (54) Tensile stress and bending stress introduced into the main member 10 by rotating the screw shaft 54 using the handle 55 so that the upper end is in contact with the spherical groove 56 of the upper plate 51 coupled to the upper fixing member. maintaining the prestress of

d) removing the hydraulic jack 60 used to introduce the compression tension;

e) It is characterized in that the retaining wall supported by the thumb pile is made independent of the earth pressure while excavating the ground to be excavated on the front surface of the main member 10 .

And although not specifically shown in the drawings, when the casing is used when forming a drilling hole because the ground is soft or the flow of groundwater is fast, and when the casing is pulled out after inserting the thumb stake into the installed casing, the casing can be pulled out smoothly. In order to do this, a lower central end plate 32a ′ and a lower side end plate 32b ′ are configured at the lower end of the upper fixing member 30 , and an upper central end plate 22a ′ and an upper side end plate are formed on the upper end of the auxiliary member 20 . (22b') The self-supporting retaining method using the thumb stake to introduce the pre-stress consists of the following steps.

a) forming a drilling hole using a casing to a depth at which horizontal displacement does not occur due to earth pressure while the ground is excavated at the ground excavation interface;

b) the main member 10, the upper fixing member 30 whose lower end is blocked by the lower central end plate 32a', the auxiliary member 20 whose upper end is blocked by the upper central end plate 22a', and a tension jack 50 inserting the configured thumb stake into the drilling hole with the auxiliary member 20 facing the front of the excavation part while the tension jack 50 protrudes above the drilling hole;

c) burying high-quality earth and sand in the drilling hole, then pulling out/removing the casing;

d) coupling the lower side end plates 32b' to both sides of the lower central end plate 32a', and coupling the upper side end plates 22b' to both sides of the upper central end plate 22a';

e) After installing hydraulic jacks 60 on both sides of the tension jack 50 and applying a predetermined compressive tension to the lower end of the upper fixing member 20 and the upper portion of the auxiliary member 20, the upper end of the screw shaft 54 is coupled to the upper fixing member maintaining the pre-stress of the tensile stress and the bending stress introduced into the main member 10 by rotating the screw shaft 54 using the handle 55 so as to be in contact with the spherical groove 56 of the upper plate 51;

f) removing the hydraulic jack 60 used for introducing the compression tension;

g) separating and removing the lower side end plate 32b' and the upper side end plate 22b' coupled to the side surfaces of the lower central end plate 32a' and the upper central end plate 22a';

h) The retaining wall supported by the thumb pile while excavating the ground to be excavated on the front surface of the main member 10 is characterized in that it comprises a step of supporting the earth pressure and standing on its own.

As described above, although the present invention has been described with reference to limited embodiments and drawings, the terms or words used in the present specification and claims are not to be construed as being limited to conventional or dictionary meanings, and to the technical spirit of the present invention. It must be interpreted with a corresponding meaning and concept. Therefore, the configuration shown in the embodiments and drawings described in the present specification is only one embodiment of the present invention, and does not represent all the technical spirit of the present invention, so within the limit that does not depart from the scope of the claims of the present invention, various It should be understood that there may be equivalents and variations.

10: main member 11: bolt hole
20: auxiliary member 21: bolt hole
22: upper extended end plate 22a': upper central end plate
22b': upper side end plate 23, 23': reinforcing rib
24, 24': top plate 25: bottom plate
30: upper fixing member 31: bolt hole
32: lower extended end plate 32a': lower central end plate
32b': lower side end plate 33, 33': reinforcing rib
34, 34': top plate 40: lower fixing member
41: bolt hole 42: upper end plate
50: tension jack 51: top plate
52: lower plate 53: holder
54: screw shaft 55: handle
56: spherical groove 60: hydraulic book
70: coupling nut 80: coupling bolt
90: spacing rod

Claims (8)

A main member 10 in which a plurality of bolt holes 11 are perforated at a predetermined position of the front flange located on the front side of the excavation unit in an H-beam structure supporting the earth pressure acting on the rear surface of the excavation unit;
Auxiliary member 20 of the H-beam structure in which the bolt hole 21 corresponding to the bolt hole 11 perforated in the front flange of the main member 10 is perforated in the flange;
an upper fixing member 30 fastened to the front flange of the upper end of the main member 10 with a coupling nut 70 and a coupling bolt 80;
a lower fixing member 40 fastened to the front flange of the lower end of the main member 10 with a coupling nut 70 and a coupling bolt 80;
In order to attach the auxiliary member 20 to the front flange of the main member 10, a coupling bolt that is pre-fastened with the coupling nut 70 in the bolt holes 11 and 21 formed in the main member 10 and the auxiliary member 20 ( 80);
After applying a compressive tension to the auxiliary member 20 with the hydraulic jack 60 installed between the upper fixing member 30 and the auxiliary member 20, the upper and lower fixing members 30 and 40 and the auxiliary member 20 are Pre-stressed thumb pile, characterized in that it maintains the compressive tension with a tension jack (50) installed between the upper fixing member (30) and the auxiliary member (20).
The method according to claim 1,
A lower end of the upper fixing member 30 is blocked by a lower extended end plate 32 or a lower central end plate 32a', and an upper end of the lower fixing member 40 is blocked by an upper end plate 42, and the auxiliary member Prestress-introduced thumb, characterized in that the upper end and lower end of (20) are blocked by the upper end plate 22 and the lower end plate 25, respectively, or the upper central end plate 22a' and the lower end plate 25 pile.
The method according to claim 1,
The bolt hole punched in the flange of the auxiliary member 20 is a hydraulic jack 60 in a state where the auxiliary member 20 is pre-fastened with the main member 10 by the coupling nut 70 and the coupling bolt 80 and is in close contact. Prestressed thumb pile, characterized in that the auxiliary member 20 is formed in an elliptical shape to enable micro-movement downward by the compressive tension force.
3. The method according to claim 2,
The lower central end plate 32a' and the lower side end plate 32b' connected from the side are integrally coupled with the reinforcing rib 33' and the back plate 34', and the upper central end plate 22a' and the side surface The upper side end plate (22b') connected continuously from the pre-stressed thumb pile, characterized in that it is integrally coupled with the reinforcing rib (23') and the back plate (24').
The method according to claim 1,
The tension jack 50 is fixed to the upper surface of the central part of the lower plate 52 and has a holder 53 having a thread on its inner surface, and is screwed to the thread of the holder 53 and a handle 55 is formed in the middle to rotate it. The length can be adjusted through the screw shaft 54 having a spherical cross section at the top, and the upper fixing member 30 is coupled to the lower end, and the lower surface is formed with a spherical groove 56 coupled to the spherical shape of the screw shaft 54 upper part. Prestress-introduced thumb stakes, characterized in that consisting of an upper plate (51).
The method according to claim 1,
The auxiliary member 20 and the main member 10 maintain a certain distance by coupling and fixing a gap maintaining rod 90 having a length equal to the flange width and a predetermined diameter to the rear flanges of both ends of the auxiliary member 20 by welding. Pre-stress-introduced thumb stakes, characterized in that they are hardened.
The self-supporting retaining method using thumb stakes introduced with pre-stress,
a) forming a drilling hole to a depth at which horizontal displacement does not occur due to earth pressure while the ground is excavated at the ground excavation interface;
b) the main member 10, the upper fixing member 30 whose lower end is closed with the lower extended end plate 32, the lower fixed member 40, the auxiliary member 20 whose upper end is closed with the upper extended end plate 22, tension Inserting the thumb pile composed of the jack 50 into the drilling hole with the auxiliary member 20 facing the front of the excavation part while the tension jack 50 protrudes above the drilling hole;
c) After filling the drilling hole with good quality soil, hydraulic jacks 60 are installed on both sides of the tension jack 50, and a predetermined compressive tension is applied to the lower part of the upper fixing member 20 and the upper part of the auxiliary member 20, and then the screw shaft (54) Tensile stress and bending stress introduced into the main member 10 by rotating the screw shaft 54 using the handle 55 so that the upper end is in contact with the spherical groove 56 of the upper plate 51 coupled to the upper fixing member. maintaining the prestress of
d) removing the hydraulic jack 60 used to introduce the compression tension;
e) A self-supporting retaining method using a prestress-introduced thumb stake, characterized in that the retaining wall supported by the thumb pile supports the earth pressure and becomes independent while excavating the ground to be excavated on the front surface of the main member 10.
The self-supporting retaining method using thumb stakes introduced with pre-stress,
a) forming a drilling hole using a casing to a depth at which horizontal displacement does not occur due to earth pressure while the ground is excavated at the ground excavation interface;
b) the main member 10, the upper fixing member 30 whose lower end is blocked by the lower central end plate 32a', the auxiliary member 20 whose upper end is blocked by the upper central end plate 22a', and a tension jack 50 Inserting the configured thumb pile into the drilling hole with the auxiliary member 20 facing the front of the excavation part while the tension jack 50 protrudes above the drilling hole;
c) burying high-quality earth and sand in the drilling hole, then pulling out/removing the casing;
d) coupling the lower side end plates 32b' to both sides of the lower central end plate 32a', and coupling the upper side end plates 22b' to both sides of the upper central end plate 22a';
e) After installing hydraulic jacks 60 on both sides of the tension jack 50 and applying a predetermined compressive tension to the lower end of the upper fixing member 20 and the upper portion of the auxiliary member 20, the upper end of the screw shaft 54 is coupled to the upper fixing member maintaining the pre-stress of the tensile stress and the bending stress introduced into the main member 10 by rotating the screw shaft 54 using the handle 55 so as to be in contact with the spherical groove 56 of the upper plate 51;
f) removing the hydraulic jack 60 used for introducing the compression tension;
g) separating and removing the lower side end plate 32b' and the upper side end plate 22b' coupled to the side surfaces of the lower central end plate 32a' and the upper central end plate 22a';
h) A self-supporting retaining method using a prestress-introduced thumb stake, characterized in that the retaining wall supported by the thumb pile supports the earth pressure while excavating the ground to be excavated in the front of the main member 10 and becomes independent.

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