Pile construction method and earth retaining wall construction method

Abstract

To provide a method for constructing a pile which does not discharge soil, and a method for constructing an earth retaining wall using the pile.SOLUTION: A method of constructing a pile includes a drilling step of drilling a hole by inserting a cylindrical sheath pipe 1 into the ground from a front end portion of the sheath pipe 1, a pile insertion step of inserting an H-shaped steel 4 as a pile member extending linearly into the sheath pipe 1 inserted into the ground, and a pipe extraction step of extracting the sheath pipe 1 from the ground, and in the drilling step, the sheath pipe 1 is inserted into the ground in a state where the front end portion is sealed with a lid member 3.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a method for constructing piles and a method for constructing an earth retaining wall. [Background technology]

[0002] Patent Document 1 discloses a method for constructing mortar piles. In this method, a hole is first drilled in the ground using a casing pipe with a bit attached to its tip. During drilling, water is discharged from the tip of the casing pipe. Next, an H-shaped steel beam is inserted into the drilled hole, and mortar is poured into the hole. The casing pipe is then removed. This completes the construction of the mortar pile. This mortar pile construction method is said to be able to use a small boring machine used for casing drilling. Furthermore, this mortar pile construction method does not cause noise or ground upheaval, making it possible to construct without constraints even on narrow roads. Mortar piles constructed using this method are formed at predetermined intervals and are used to construct water-stopping walls or earth-retaining walls. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-47653 Summary of the Invention [Problem to be solved by the invention]

[0004] In the method described in Patent Document 1, when drilling holes in the ground, there are cases where discharged soil (earth and sand) gets into the sheath pipe such as a casing pipe. In addition, the method described in Patent Document 1 has the problem that the discharged soil containing water must be disposed of because the hole is drilled while water is being discharged. Therefore, it is desirable to provide a driving method that does not result in discharged soil when driving piles into the ground, and a method for constructing an earth retaining structure using this method.

[0005] The present invention has been made in view of the above circumstances, and its object is to provide a method for constructing piles that does not cause soil removal, and a method for constructing an earth retaining structure using the same. [Means for solving the problem]

[0006] In order to achieve the above object, the pile construction method according to the present invention comprises the steps of: a drilling step of inserting the tip of the cylindrical sheath pipe into the ground and drilling a hole; a pile insertion step of inserting a pile member extending linearly into a sheath pipe inserted into the ground; a tube removal step of removing the sheath tube from the ground, In the hole-boring step, the sheath pipe is inserted into the ground with the tip portion sealed with a lid member.

[0007] The pile construction method according to the present invention further comprises: In the tube removal step, the cover member may be left in the ground.

[0008] The pile construction method according to the present invention further comprises: In the hole-boring step, the hole may be drilled by a dry method in which water is not supplied to the ground in the vicinity of the tip.

[0009] The pile construction method according to the present invention further comprises: The pile member may be an H-beam.

[0010] The pile construction method according to the present invention further comprises: In the hole-making step, a cutting edge for hole-making may be formed at the tip of the sleeve pipe, and the sleeve pipe may be rotated to make the hole.

[0011] The pile construction method according to the present invention further comprises: In the hole drilling step, the hole may be drilled while the surface of the cover member on the base end side of the sheath pipe is urged toward the ground by the tip end of the sheath pipe.

[0012] The pile construction method according to the present invention further comprises: The method may further include a filling step of filling a filler material into the sheath pipe into which the pile member is inserted.

[0013] The pile construction method according to the present invention further comprises: The filler may be sand.

[0014] In order to achieve the above object, the method for constructing an earth retaining wall according to the present invention comprises: A plurality of parent piles may be constructed by the pile construction method described above, and sheet piles may be inserted between the parent piles to construct a retaining wall. [Effects of the Invention]

[0015] It is possible to provide a method for constructing piles that does not cause soil removal and a method for constructing an earth retaining wall using the piles. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 4 is an exploded view of a sleeve tube and a cover member. [Figure 2] FIG. [Figure 3] FIG. 10 is a side view of the sleeve pipe to which the lid member is attached. [Figure 4] 10A and 10B are diagrams illustrating the arrangement of the cover member in the hole drilling process. [Figure 5] 10A and 10B are diagrams illustrating the state in which the hole is sealed with a lid member in the hole drilling process. [Figure 6] 10A and 10B are diagrams illustrating the state of holes drilled in the hole drilling step. [Figure 7] FIG. 10 is an explanatory diagram of a pile insertion process. [Figure 8] FIG. [Figure 9] FIG. 10 is an explanatory diagram of the extubation process. [Figure 10] FIG. 10 is a top view of the hole after the filling step. [Figure 11] FIG. 10 is a top view of the hole after the extubation step. [Figure 12] This is a top view of the retaining wall. DETAILED DESCRIPTION OF THE INVENTION

[0017] A pile construction method and a retaining wall construction method using the same according to an embodiment of the present invention will be described with reference to the drawings. First, an outline of the pile construction method and the retaining wall construction method using the same according to the present embodiment will be described.

[0018] The pile construction method according to this embodiment includes a hole drilling step in which a straight, cylindrical sheath pipe is inserted into the ground from its tip and drilled; a pile insertion step in which a pile member extending linearly is inserted into the sheath pipe inserted into the ground; and a pipe removal step in which the sheath pipe is pulled out of the ground; in the hole drilling step, the sheath pipe is inserted into the ground with its tip sealed with a lid member.

[0019] In the pile construction method according to this embodiment, piles can be constructed without causing soil removal.

[0020] The method for constructing an earth retaining wall according to this embodiment involves constructing a plurality of parent piles using the pile construction method according to this embodiment, and inserting sheet piles between these parent piles to construct an earth retaining wall.

[0021] In the method for constructing a retaining wall according to this embodiment, piles can be constructed without causing soil removal, and these piles can be used as the main piles of the retaining wall.

[0022] The pile construction method according to this embodiment and the method for constructing an earth retaining wall using the pile will be described in detail below. In the following description, the lower side in the vertical direction (the direction perpendicular to the ground surface (ground)) may be simply referred to as "lower" and the upper side may be simply referred to as "upper side." In other words, with the ground surface as the reference, the inside of the ground as viewed from the ground surface is the lower side, and the outside of the ground is the upper side.

[0023] As described above, the method for constructing an earth retaining wall according to this embodiment includes the drilling step, the pile insertion step, and the pipe removal step. The method for constructing an earth retaining wall according to this embodiment may further include a filling step of filling a filler material into the sheath pipe into which the pile member has been inserted, as will be described later.

[0024] The hole drilling process is a process in which the tip of the sheath pipe is inserted into the ground to drill a hole. A cylindrical sheath pipe is used. The axis of the sheath pipe is preferably linear. In other words, the sheath pipe preferably extends in a straight line. Below, an example will be described in which the sheath pipe is inserted perpendicular to the ground surface, but the sheath pipe may also be inserted at an angle to the ground surface.

[0025] The sheath pipe is a guide member for inserting the pile member into the ground in the pile insertion step described later. The sheath pipe can guide the pile member if it is tubular, but from the viewpoint of strength, it is preferably a steel pipe, for example.

[0026] In the drilling process, the tip of the sheath pipe is sealed with a lid member while drilling. Specifically, with the tip of the sheath pipe sealed with the lid member, the tip of the sheath pipe is inserted into the ground together with the lid member. This makes it possible to prevent the excavated soil from entering the sheath pipe during drilling. In other words, drilling can be performed without excavating soil.

[0027] When drilling a hole with the tip of the sheath pipe sealed with the lid member, it is advisable to drill the hole while pressing the tip of the sheath pipe with the base end side of the lid member (the surface facing above ground, the upper surface) facing into the ground (facing downward). This allows the sheath pipe to be inserted into the ground, and the lid member to be inserted into the ground. It also ensures that the tip of the sheath pipe is securely sealed.

[0028] An example of the lid member is a flat plate member that is separate from the sleeve pipe. The lid member may be formed, for example, from a steel material. The lid member may have a shape that protrudes downward, for example. An example of a shape that protrudes downward is a spine shape such as a cone. The lid member does not include those that include cutting teeth that rotate integrally with the pile (so-called bits). In other words, lid members in this embodiment do not include those that include cutting teeth that rotate integrally with the pile. It is preferable that the lid member has a shape that can be formed inexpensively. It is preferable that the lid member 3 is formed from an inexpensive material.

[0029] In the drilling step, a cutting edge for drilling holes may be formed at the tip of the sheath pipe, and the sheath pipe may be rotated to drill holes. By rotating the sheath pipe, the cutting edge at the tip can cut the ground and drill holes.

[0030] In the drilling process, it is advisable to drill using a dry method that does not supply water to the ground near the tip of the sheath pipe, thereby avoiding the generation of wet soil discharge.

[0031] The pile insertion process is a process of inserting a pile member extending linearly into a sheath pipe inserted into the ground. In other words, the pile insertion process is a process of inserting a pile member into the ground using the sheath pipe as a guide member. In the above-mentioned drilling process, the removed soil does not enter the sheath pipe, so in the pile insertion process, the pile member can be inserted into the sheath pipe without the need for soil removal processing (the work of removing the removed soil) inside the sheath pipe. In the pile insertion process, the position of the pile member is regulated by the sheath pipe, so the plumbing accuracy of the pile member is naturally ensured.

[0032] The pile members used in the pile insertion process can be of any type or material as long as they extend linearly and can be used as piles. Examples of pile members include metal rods, pipes, or H-beams made of iron or iron alloys. When constructing a retaining wall using a steel sheet pile retaining wall construction method, it is preferable to use H-beams as the pile members.

[0033] The pipe removal step is a step of removing only the sheath pipe from the ground. In the pipe removal step, the pile member is left in the ground, i.e., left in the hole in the ground formed by the sheath pipe.

[0034] In the pile construction method according to this embodiment, after the pipe removal step, a filling material may be filled into the hole in the ground formed by the sheath pipe to fill (fill) the gap between the pile and the ground, thereby fixing the pile to the ground. Also, after the pile insertion step and before the pipe removal step, a filling step may be performed in which a filling material is filled into the sheath pipe into which the pile member has been inserted, so that the gap between the pile and the ground is naturally filled (the gap is filled with the filling material) during the process of pulling out the sheath pipe from the ground in the pipe removal step.

[0035] During the pipe removal process, friction between the sheath pipe and the ground may cause a portion of the inner wall (ground) of the hole formed by the sheath pipe to collapse. When such collapse occurs, part of the gap between the pile and the ground within the extension range of the pile (hole) may be blocked by soil and sand from the collapsed ground. When such blockage occurs, it may not be possible to completely fill the gap between the pile and the ground with filler afterwards. Therefore, in the pile construction method according to this embodiment, it is preferable to perform the filling process after the pile insertion process and before the pipe removal process.

[0036] Examples of fillers in the filling process are grout, cement and sand.

[0037] Piles constructed using the pile construction method according to this embodiment are suitable as parent piles for earth retaining walls. When constructing an earth retaining wall, multiple parent piles are constructed using the pile construction method according to this embodiment, and sheet piles are inserted between these parent piles.

[0038] A specific example of the pile construction method according to this embodiment will be described below.

[0039] FIG. 1 shows an example of a sheath pipe 1 and a lid member 3 that seals the entrance of the sheath pipe 1. The sheath pipe 1 has a steel pipe 10 and a bit 2 that is attached to the tip of the steel pipe 10 and has a cutting edge 20 for drilling holes. The lid member 3 is attached to the tip of the sheath pipe 1, serves as a lid for the tip of the sheath pipe 1, and seals the entrance of the sheath pipe 1. FIG. 1 shows the steel pipe 10, the bit 2, and the lid member 3 in an expanded state. FIG. 2 shows an enlarged view of the bit 2. FIG. 3 shows the sheath pipe 1 with the bit 2 attached to the steel pipe 10, and the lid member 3 attached to the tip of the sheath pipe 1. FIGS. 1 to 3 are side views.

[0040] As shown in Figures 1 to 3, the bit 2 is formed in a cylindrical shape. A cutting portion 20 is formed at the tip of the cylinder of the bit 2. The tip of the bit 2 is an expanded diameter portion 23 whose inner diameter is larger than that of the base end side, and a stepped surface 24 (see Figure 2) facing the tip side is formed on the inner periphery of the cylinder, at the base end of the expanded diameter portion 23. The stepped surface 24 is formed in an annular shape when viewed along the axial direction of the cylinder of the bit 2.

[0041] As shown in Fig. 1, the lid member 3 is separate from the sleeve tube 1. As shown in Figs. 1 and 3, the lid member 3 may be flat. As shown in Fig. 3, the lid member 3 is adapted to fit into the cylindrical interior of the expanded diameter portion 23. When the lid member 3 is fitted into the cylindrical interior of the expanded diameter portion 23, the surface (upper surface) on the base end side is supported by a stepped surface 24 (see Fig. 2).

[0042] As shown in Figure 1, a socket 12 having an inner diameter larger than that of the base end is formed at the tip of a steel pipe 10, and the base end of a bit 2 can be inserted into the socket 12 to fix the bit 2 to the steel pipe 10. The bit 2 may be fixed to the steel pipe 10 (socket 12) with a pin or bolt.

[0043] As shown in Figure 3, when the bit 2 is fixed to the steel pipe 10, the axis of the bit 2 overlaps with the axis of the steel pipe 10 (axis G in Figure 3), and the sheath pipe 1 extends in a straight line.

[0044] 4 to 9 show the steps of the pile construction method according to this embodiment in the order in which these steps are performed.

[0045] Figures 4 to 6 show the steps of the hole drilling process. In the hole drilling process, first, the cover member 3 is placed on the ground surface as shown in Figure 4. The cover member 3 is placed in a position that overlaps with the extension direction of the hole to be drilled (in this example, the same as the vertical direction, hereinafter sometimes referred to as the hole drilling direction).

[0046] Then, the sheath pipe 1 is supported by a steel pipe pile construction machine or the like, and the axis of the hole to be drilled is aligned with the axis of the sheath pipe 1. At this time, the internal space of the sheath pipe 1 and the cover member 3 are positioned so as to overlap when viewed in the direction of drilling.

[0047] Next, as shown in Figure 5, when the sheath pipe 1 is lowered (moved downward) toward the ground, the cover member 3 fits into the tip of the sheath pipe 1 (expanded diameter portion 23, see Figure 2), sealing the tip of the internal space of the sheath pipe 1 at the tip of the sheath pipe 1.

[0048] As shown in Figure 6, the sheath pipe 1, sealed with the lid member 3, is further lowered into the ground (downward) to drill a hole, and the tip (bit 2) of the sheath pipe 1 is inserted into the ground. The sheath pipe 1 may be rotated when drilling a hole. As the sheath pipe 1 is inserted into the ground, the base end surface (surface facing above ground, upper surface) of the sheath pipe 1 is biased toward the ground (downward) by the tip (step surface 24, see Figure 2) of the sheath pipe 1. In this state, the lid member 3 remains sealed at the tip of the internal space of the sheath pipe 1. When the sheath pipe 1 is inserted into the ground to a predetermined depth, drilling is complete.

[0049] During drilling, the cover member 3 seals the tip of the internal space of the sheath pipe 1, so no excavated soil gets inside the sheath pipe 1. Since drilling can be done dry, no excavated soil containing water is produced.

[0050] After the hole drilling is completed, a pile insertion process is carried out in which an H-beam 4 serving as a pile member is inserted into the sheath pipe 1, as shown in Figure 7. The H-beam 4 is a steel material that extends linearly. The H-beam 4 is inserted into the sheath pipe 1 along the axis of the sheath pipe 1 and left in place.

[0051] After the H-beam 4 is placed inside the sheath pipe 1, a filling step is carried out in which sand 5 is filled as a filler into the sheath pipe 1 with the H-beam 4 inserted, as shown in Fig. 8. Fig. 10 shows a view (a top view, top view) of the sheath pipe 1 and the hole 9 formed thereby, as seen from the ground. After the filling step, the space (gap) between the H-beam 4 and the inner wall surface of the sheath pipe 1 is filled with sand 5.

[0052] Thereafter, as shown in Fig. 9, a tube removal step is performed in which the sheath pipe 1 is removed from the ground. When removing the sheath pipe 1 from the ground, the cover member 3 may be left in place in the ground. If the cover member 3 has a shape that can be inexpensively processed and formed, such as a flat plate, and is made of an inexpensive material such as steel, leaving the cover member 3 in the ground will not be a burden on construction costs. Rather, the task of removing the cover member 3 from the ground will be a burden on construction costs.

[0053] When the sheath pipe 1 is pulled out from the ground, the sand 5 that was filled inside the sheath pipe 1 naturally fills the space where the sheath pipe 1 had been. That is, the space between the H-shaped steel 4 and the inner surface of the hole 9 formed by the sheath pipe 1 is filled with sand 5. FIG. 11 shows a view of the hole 9 from the ground (top view). After the filling process and the pipe removal process, the space (gap) between the H-shaped steel 4 and the inner wall surface of the hole 9 is filled with sand 5. In this way, the H-shaped steel 4 in the hole 9 becomes a pile supported by the ground via the sand 5.

[0054] As shown in Figure 12, if a plurality of H-shaped steel beams 4 are erected as piles at predetermined intervals, these piles (H-shaped steel beams 4) can be used as parent piles to construct a retaining wall 100. Figure 12 is a top view of the retaining wall 100.

[0055] The retaining wall 100 may be constructed by inserting a sheet pile 7 between a pair of H-shaped steel beams 4, 4 serving as parent piles. The sheet pile 7 may be, for example, a rectangular plate. When the H-shaped steel beam 4 is constructed along the vertical direction, the sheet pile 7 may be arranged with the end face of its end portion 71 (the end portion extending along the vertical direction) facing the web portion 41 of the H-shaped steel beam 4. The end face of the end portion 71 may abut against the plate surface of the web portion 41. The end portion 71 may be arranged between the flanges 42, 42 of the H-shaped steel beam 4.

[0056] In this way, the pile construction method according to this embodiment allows the piles to be constructed without the need for soil removal. Also, the retaining wall construction method according to this embodiment allows the retaining wall to be constructed without the need for soil removal when constructing the main piles.

[0057] Other features of the pile construction method according to this embodiment are as follows.

[0058] For example, if an H-shaped steel beam is to be constructed as a pile using a general steel pipe pile construction machine (heavy equipment dedicated to rotary burial), the H-shaped steel beam will twist, but such a problem does not occur with the pile construction method according to this embodiment.

[0059] When constructing piles by driving H-beams 4, methods such as an H-beam press-in method using a vibrating machine or an H-beam erection method involving pre-excavation using a post-setting vehicle can be used. However, the H-beam press-in method has the disadvantage of affecting the surrounding environment due to vibration and noise. The H-beam erection method involving pre-excavation requires the work of erecting the H-beam into a hole drilled with an auger, which means that it is time-consuming to ensure the plumbing accuracy of the H-beam. However, when constructing holes using the pile construction method according to this embodiment, it is possible to avoid the excessive noise and vibration that occurs with the H-beam press-in method, and since the plumbing accuracy is naturally high, it is not necessary to time-consuming to ensure the plumbing accuracy.

[0060] In this way, a method for constructing piles and a method for constructing earth retaining walls can be provided.

[0061] It should be noted that the embodiments disclosed in this specification are merely examples, and the present invention is not limited to these embodiments, and can be modified as appropriate within the scope of the purpose of the present invention. [Industrial Applicability]

[0062] The present invention can be applied to a pile construction method and a retaining wall construction method. [Explanation of symbols]

[0063] 1: Sheath tube 10: Steel pipe 100: Earth retaining wall 12: Socket 2: bit 20: Blade part 23: Expanded diameter part 24: Step surface 3: Lid member 4:H type steel 41: Web Department 42: Flange 5: Sand 7: Yaita 71: Edge 9: Hole G: Axial center

Claims

1. a drilling step of inserting the tip of the cylindrical sheath pipe into the ground and drilling a hole; a pile insertion step of inserting a pile member extending linearly into a sheath pipe inserted into the ground; a tube removal step of removing the sheath tube from the ground, In the drilling step, the sheath pipe is inserted into the ground with the tip end sealed with a lid member.

2. The pile construction method according to claim 1 , wherein the cover member is left in the ground in the pipe removal step.

3. 3. The pile construction method according to claim 1, wherein the hole drilling step is performed by a dry method in which water is not supplied to the ground in the vicinity of the tip portion.

4. 3. The pile construction method according to claim 1, wherein the pile members are H-section steel members.

5. 3. The pile construction method according to claim 1, wherein in the hole drilling step, a cutting edge for hole drilling is formed at the tip of the sheath pipe, and the hole is drilled by rotating the sheath pipe.

6. 3. The pile construction method according to claim 1 or 2, wherein in the hole drilling step, the hole is drilled while the surface of the base end side of the sheath pipe in the cover member is urged toward the ground by the tip end of the sheath pipe.

7. 3. The pile construction method according to claim 1, further comprising a filling step of filling a filler material into the sheath pipe into which the pile member is inserted.

8. 8. The method for constructing piles according to claim 7, wherein the filler material is sand.

9. A method for constructing a retaining wall, comprising constructing a plurality of parent piles by the pile construction method according to claim 1 or 2, and inserting sheet piles between the parent piles to construct a retaining wall.

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