Drilling Guide Device

Abstract

PURPOSE: To provide a drilling guide device for use in construction of an earth retaining wall.CONSTITUTION: A drilling guide device is a drilling guide device for drilling new pile holes at predetermined positions between multiple parent piles B1 having H-shaped steel 2. It comprises a guide body 61 with an axis support portion 61a formed thereon, two blade retaining materials 62, and a blade material 63. A connecting hole 81a is formed at a lower end of a drilling drill 81. The guide body 61 has an axis support portion 61a and a connecting protrusion 61b. The connecting protrusion 61b is inserted into the connecting hole 81a of the drilling drill 81. The two blade retaining materials 62 are fixed with bolts and nuts, and two bearing portions 62a hold the axis support portion 61a of the guide body 61 and the connecting plate portions 62b are fixed to each other with fasteners 64. The two blade materials 63 are attached to two blade mounting plate portions 62c so that they are point-symmetrical about the diameter center of the axis support portion 61a of the guide body 61.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to an excavation guide device used for constructing an earth retaining wall at a construction site. [Background technology]

[0002] Generally, when constructing a building, excavation work is carried out to excavate the site to a specified depth, and this excavation work always requires retaining earth. Since excavation work often involves dangers such as collapse of the surrounding ground and outflow of soil and water from the surrounding ground, retaining earth is essential work to protect the sides of the excavation. When retaining earth is required, it is necessary to decide the construction method after thoroughly considering the soil quality of the construction site, the groundwater level, surrounding buildings, and the load on the ground.

[0003] Conventionally, the following construction methods have been known for earth retaining works. That is, the most common construction method is the parent pile and horizontal sheet pile method. In this parent pile and horizontal sheet pile method, first, H-shaped steel as parent piles are buried in the ground in series at the same specified intervals, and then multiple horizontal sheet piles are manually inserted between the H-shaped steel without gaps (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-204834 A [Patent Document 2] JP 2008-208599 A DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0005] However, in the technology disclosed in Patent Document 1, multiple H-shaped steel beams are embedded and a large number of cross sheet piles are fitted between the H-shaped steel beams, which requires the site to be excavated to a specified depth. This requires large-scale excavation work and the problem is that the preparation stage for fitting multiple cross sheet piles tightly between the H-shaped steel beams requires a lot of time and effort.

[0006] In addition, since excavation must be performed to a specified depth, this method is not suitable for locations with poor geology, weak ground, or excessive soil pressure. For example, if the site is near a river, water will flow out as the site is excavated, making work difficult.

[0007] Furthermore, the skills required to manually fit multiple cross sheet piles between the H-shaped steel beams without any gaps are being required, but there are fewer experienced sheet pile craftsmen with this skill, which means that the work is not progressing as expected. In addition, it is becoming difficult to obtain timber suitable for cross sheet piles, and the larger the construction site, the greater the number of sheet piles required, making it even more difficult to obtain cross sheet piles.

[0008] Furthermore, although there is a technique using cement as an earth retaining wall as described in Patent Document 2, etc., in this case, a large amount of cement is used, which increases costs and construction time.The object of the present invention is to provide an excavation guide device that can accurately excavate pile holes at planned positions in the construction of an earth retaining wall at a construction site, which can easily form an earth retaining wall regardless of the geology of the site and without digging the site deeply. [Means for solving the problem]

[0009] Therefore, the inventors have conducted intensive research to solve the above problems, and as a result, have come up with the invention of claim 1, which is a drilling guide device connected to the lower end of a drilling drill for drilling new pile holes for injecting cement milk at predetermined positions between a plurality of parent piles having H-shaped steel beams, the device comprising: a guide body having a pivotal support part formed at an intermediate position in the axial center; two blade retaining members attached to the pivotal support parts; and a blade member, the lower end of the drilling drill being formed with a connected hole, the guide body having a pivotal support part and a connecting protrusion part, the connecting protrusion part being inserted into the connected hole of the drilling drill and fixed with bolts and nuts, the blade retaining member comprising a semicircular arch-shaped bearing part, connecting plate parts extending outward from both ends of the bearing part in the width direction, and a blade attachment plate part extending radially from a predetermined position of the bearing part, The tips of the two blade materials enter the U-shaped portion formed by both flanges and the web of the H-shaped steel of the parent pile, and the tips of the blade materials abut against the flanges of the H-shaped steel and are close to the web. The blade materials attached via the blade retaining material attached to the guide body rotate on a horizontal plane together with the guide body which rotates in accordance with the rotation of the drilling drill, and when the blade materials abut against the flanges of the H-shaped steel, the rotation stops together with the blade retaining material. The blade materials of the excavation guide device mix soil and injected cement milk within their movable range during excavation work. The above problem has been solved by providing an excavation guide device characterized by the above.

[0010] The above problem is solved by the invention of claim 2, which is the excavation guide device according to claim 1, characterized in that the blade materials are prepared with a variety of different lengths in the longitudinal direction.The above problem is solved by the invention of claim 3, which is the excavation guide device according to claim 1 or 2, characterized in that the two blade materials used are of different lengths in the longitudinal direction.The above problem is solved by the invention of claim 4, which is the excavation guide device according to claim 1 or 2, characterized in that the two blade materials used are of the same length in the longitudinal direction. Effect of the Invention

[0011] In the invention of claim 1, the tips of the two blades of the drilling guide device enter between the flanges of the H-shaped steel of the parent pile, and the tips of the blades are close to or in contact with the flanges or web of the H-shaped steel. When drilling a hole in the intermediate wall between the H-shaped steel of the parent piles, the drilling guide device itself tries to rotate as the drilling drill rotates, but when the blades abut the flanges of the H-shaped steel, the drilling guide device rotates idly relative to the shaft support of the guide body, and the shaft center of the drilling drill is maintained at a constant position by the H-shaped steel of the adjacent parent piles, and the intermediate wall hole in the intermediate wall can be accurately drilled without being affected by the side wall hole in the nearby side wall. In this way, the drilling guide device serves as a guide to accurately maintain the direction of travel of the drilling drill, loop head, tip drilling mechanism, etc. from the start of drilling. Furthermore, the blades of the drilling guide device also serve to stir the soil and the cement milk to be injected within the rotational range during the drilling work.

[0012] In the invention of claim 2, blade materials 63 are prepared in various different lengths in the longitudinal direction, so that the blade material alone can be replaced without removing the blade retaining material from the guide body. In the invention of claim 3, two blade materials of different lengths in the longitudinal direction are used, which is suitable for excavating an intermediate wall hole located toward one of the H-shaped steel beams rather than the middle between the two H-shaped steel beams of adjacent parent piles. In the invention of claim 4, two blade materials of the same length in the longitudinal direction are used, which is suitable for excavating an intermediate wall hole located in the center of the two H-shaped steel beams between adjacent parent piles. [Brief description of the drawings]

[0013] [Figure 1] 1A is an oblique view of a key portion of a retaining wall according to the present invention, (B) is a longitudinal front view of a key portion of the retaining wall, (C) is a cross-sectional view taken along the X1-X1 arrow of (B), (D) is a cross-sectional view taken along the X2-X2 arrow of (B), and (E) is an enlarged view of part (α) of (B). [Diagram 2](A) is a schematic cross-sectional plan view of the retaining wall in the retaining construction area, (B) is an enlarged view of part (β) of (A), (C) is an enlarged view of part (γ) of (A), and (D) is a schematic cross-sectional plan view of the main parts of a unit wall body with one intermediate wall. [Diagram 3] 13(A) to 13(C) are a cross-sectional plan view and a longitudinal front view showing the structure of the parent pile. [Figure 4] 4(A) to 4(C) are a cross-sectional plan view and a longitudinal front view showing the structure of the side walls and the intermediate wall. [Diagram 5] This is a diagram showing steps 1 to 3 of the construction of the parent piles. [Figure 6] This is a diagram of steps 4 to 6 showing the construction of the parent piles until completion. [Figure 7] This is a diagram of steps 7 to 10 until the construction of the side wall is completed. [Figure 8] FIG. 1 is a diagram showing steps 11 to 14 until the construction of the intermediate wall is completed. [Figure 9] 1A is an exploded perspective view of the drilling guide device, and FIG. 1B is a perspective view of a state in which a lower part of a drilling drill is connected to the drilling guide device. [Figure 10] 1A is a front view of a drilling guide device attached to a drilling drill, (B) is a front view of the drilling guide device disassembled, (C) is a cross-sectional view of the main parts of the drilling guide device, and (D) is a cross-sectional view of the connecting part between the drilling guide device and the drilling drill. [Figure 11] 1(A) to 1(C) are diagrams showing a state in which the excavation guide device is used. BEST MODE FOR CARRYING OUT THEINVENTION

[0014] Hereinafter, an embodiment of an earth retaining wall, an earth retaining wall construction method, and an excavation guide device according to the present invention will be described with reference to the drawings. First, the earth retaining wall will be described, followed by the earth retaining wall construction method and the excavation guide device. The earth retaining wall is constructed in the shape of a closed enclosure wall (see FIG. 2(A)). Specifically, an earth retaining construction area A is set first. The earth retaining construction area A refers to the area for constructing the earth retaining wall on the land or site on which the earth retaining wall is to be constructed (see FIG. 2(A)). The parent piles B1, side walls 4, and intermediate walls 5 that constitute the earth retaining wall are constructed along the boundary line of the earth retaining construction area A (see FIG. 2(A)).

[0015] The retaining construction area A is composed of straight line portions along the X and Y directions and multiple corners (see Fig. 2(A)). The lines in the X direction that determine the retaining construction area A are the area boundary line Jx, and the lines in the Y direction are the area boundary line Jy. The retaining construction area A also has protruding corners To, which are corners facing outward, and recessed corners Ti, which are corners recessed inward.

[0016] Here, for the sake of convenience in explaining the invention, the X direction and the Y direction are used as terms indicating directions, and in principle, the horizontal direction of the retaining construction area A is taken as the X direction, the area boundary line Jx is taken as the horizontal line, and the vertical direction is taken as the Y direction, and the area boundary line Jy is taken as the vertical line (see Fig. 2). However, for the X and Y directions, the X direction may be taken as the vertical direction and the Y direction as the horizontal direction, and the area boundary line Jx may be taken as the vertical line and the area boundary line Jy as the horizontal line.

[0017] Furthermore, the aforementioned parent piles B1, side walls 4, and intermediate walls 5 exist as structures for constructing an earth-retaining wall in the earth-retaining construction area A (see Figs. 1(A), (B), (C), 2, 4(C), etc.). The parent piles B1 are arranged at predetermined intervals along the boundary line of the earth-retaining construction area A, and side walls 4, 4 and two or one intermediate walls 5 are formed between each of the adjacent parent piles B1, B1 in the multiple parent piles B1 arranged along the boundary line of the earth-retaining construction area A.

[0018] A part of the side wall 4 and a part of the intermediate wall 5 intersect in the width direction (horizontal direction), and these are continuously connected to form an earth retaining wall in the earth retaining construction area A. The partial wall body formed by the side wall 4 and the intermediate wall 5 formed between the adjacent parent piles B1, B is referred to as a unit wall body B2 (see Figure 2).

[0019] The parent pile B1 is composed of a parent pile hole portion 1, an H-shaped steel 2 as the pile core, and a concrete support portion 3 (see Fig. 3(A)), with the H-shaped steel 2 embedded in the parent pile hole portion 1 (see Fig. 3(B)), and the H-shaped steel 2 fixedly supported in the parent pile hole portion 1 by the concrete support portion 3 (see Fig. 3(C)). In constructing the parent pile B1, first the parent pile hole portion 1 is excavated in the position in the retaining construction area A where the parent pile B1 is to be constructed, in order to drive the H-shaped steel 2 into the pile (see step 2 in Fig. 5).

[0020] In order to facilitate the driving of the H-shaped steel 2 into the ground, a pile hole 1 with an inner diameter larger than the H-shaped cross-sectional shape of the H-shaped steel 2 is excavated by the drill shaft of an excavation machine. The H-shaped steel 2 is inserted upright into the pile hole 1 (see Figures 3(B) and (C) and step 5 in Figure 6). The total length of the H-shaped steel 2 is slightly longer than the total depth of the pile hole 1, and when the H-shaped steel 2 is completely driven into the pile hole 1, the upper tip of the H-shaped steel 2 protrudes slightly from the opening of the pile hole 1.

[0021] A concrete support section 3 is provided from the bottom surface to approximately the middle of the total depth of the pile hole section 1 over the entire depth from the opening to the bottom surface of the pile hole section 1 (see Figs. 1(B), (D), 3(B), and (C)). The concrete support section 3 covers the H-shaped steel 2 so that the section from the bottom to the middle position in the longitudinal direction is embedded in concrete, and the outer periphery and bottom surface of the concrete support section 3 are in close contact with the inner periphery and bottom of the pile hole section 1, so that the H-shaped steel 2 is securely fixed and supported in the pile hole section 1 (see Figs. 1(A), (B), and (D)).

[0022] The concrete support 3 is formed by solidifying liquid cement milk injected into the parent pile hole 1. The parent pile hole 1 is then backfilled with the embankment that was removed during excavation onto the concrete support 3 and piled up around the opening until it closes the opening of the parent pile hole 1 (see Fig. 3(C) and Fig. 6, step 6). Parent piles B1 with this configuration are constructed at predetermined intervals along the area boundary line Jx and area boundary line Jy of the retaining construction area A (see Fig. 2(A)).

[0023] Next, construction of the side wall 4 of the unit wall B2 constructed between adjacent parent piles B1, B1 will be explained. In principle, two side walls 4 are constructed (see Figs. 1(A), (B), and (C)). The side wall 4 is composed of a side wall hole 41 and a side wall concrete part 42 formed by solidifying cement milk injected into the side wall hole 41. The side wall 4 is approximately cylindrical (see Figs. 1(A), (C), and 2(B), (C), and (D)).

[0024] Furthermore, part of the cylindrical outer shape of the side wall 4 enters into the gap S between both flanges 21, 21 of the H-shaped steel 2 of the parent pile B1, and the part of the side wall 4 that enters into the gap S is configured to abut or be close to the web 22 of the H-shaped steel 2 (see Figs. 1(A), (C) and 2). Also, the side wall hole 41 is structured so that a part of it inevitably intermingles with the parent pile hole 1 (see Figs. 1(B), 4(A) and (B), Fig. 7 step 8 and step 9, etc.).

[0025] The side wall 4 is set shallower than the depth of the parent pile B1. Specifically, the depth of the side wall 4 is slightly more than half the depth of the parent pile portion B (see Figs. 1(B), (E), 4(A), (B)). The lower part of the side wall 4 and the upper part of the concrete support portion 3 of the parent pile B1 have a part where they intersect in the depth direction (or the up-down direction) (see Figs. 1(A), (B), (C), (E)).

[0026] In other words, the above-mentioned configuration of the parent pile B1 and the side wall 4 is such that the depth dimension of the side wall 4 is greater than the depth dimension from the opening of the parent pile hole 1 to the upper end of the concrete support part 3 (see FIG. 1). In other words, if the depth dimension from the opening of the parent pile hole 1 to the upper end of the concrete support part 3 is H1, and the depth of the side wall concrete part 42 or the side wall hole part 41 of the side wall 4 is H2, H2>H1.

[0027] The concrete support portion 3 and the side wall concrete portion 42 of the side wall 4 are If the intersection point in the vertical direction is taken as intersection 90, The intersection dimension h is h=H2-H1. Here, the intersection dimension h in the vertical direction (depth direction) between the concrete support portion 3 of the parent pile B1 and the side wall concrete portion 42 of the side wall 4 (see Figures 1(B) and (E)) is, specifically, if the depth of the parent pile B1 is approximately 10 m, the intersection dimension h of the intersection portion 90 is approximately 1 m.

[0028] In other words, an upper part of the concrete support part 3 of the parent pile B1 and a lower part of the side wall 4 have an intersection part 90 in the vertical direction, and the concrete support part 3 and the side wall concrete part 42 of the side wall 4 are continuously connected to each other in the depth direction (or vertical direction) of the concrete support part 3 and the side wall concrete part 42 of the side wall 4. The intersection dimension h of the intersection part 90 is not limited to the above numerical value, but may be changed appropriately depending on the depth dimension of the parent pile hole part 1 and the side wall hole part 41, and may be about 0.5 m to about 2 m.

[0029] Here, the excavation of the side wall hole 41 in the side wall 4 and the injection of the cement milk are carried out before the cement milk for constructing the concrete support portion 3 of the parent pile B1 has completely solidified and is still in a fluid state. In other words, the side wall hole 41 in the side wall 4 and the injection of the cement milk into the side wall hole 41 are carried out when the concrete portion of the concrete support portion 3 has not yet solidified and is in a liquid state and can be mixed with the cement milk that forms the side wall 4.

[0030] This causes the concrete support portion 3 of the parent pile B1 and the side wall concrete portion 42 formed by the solidification of the cement milk in the side wall 4 to mix together, thereby integrating the concrete support portion 3 and the side wall concrete portion 42 of the side wall 4 (see Figures 1, 4(B) and (C)).

[0031] Additionally, the area where the embankment has been backfilled in the pile hole 1 of the pile B1 intersects with the side wall 4. In the process of injecting cement milk into the pile hole 1 of the pile B1 and the side wall hole 41 of the side wall 4, the cement milk also flows into the pile hole 1, and the embankment backfilled in the pile hole 1 and the cement milk injected into the side wall hole 41 mix together.

[0032] Then, the cement milk injected into the side wall hole 41 within the parent pile hole 1 and above the concrete support portion 3 mixes with the embankment and becomes a mortar-like material, which hardens and forms a cylindrical wall above the concrete support portion 3, with approximately the same diameter as the concrete support portion 3. This cylindrical wall is mortar-like and has different properties from the concrete support portion 3, but has sufficient strength, and the cylindrical wall and the side wall 4 are continuously mixed in the vertical direction, so that the parent pile B1 and the side wall 4 form a continuous wall portion.

[0033] Next, the depth of the intermediate wall 5 is the same or approximately the same as the depth of the side wall 4 (see Figs. 1(A), (B) and 4(C)). The outer diameter of the intermediate wall 5 is larger than the outer diameter of the side wall 4. Furthermore, the intermediate wall 5 is configured so that a cross section perpendicular to the vertical direction intersects with a cross section perpendicular to the vertical direction of the side wall 4. In other words, the side wall 4 and the intermediate wall 5 are configured to be continuously and partially intertwined in the vertical direction.

[0034] The intermediate wall 5 is composed of an intermediate wall hole portion 51 and an intermediate wall concrete portion 52. First, the intermediate wall hole portion 51 is excavated, cement milk is injected into the intermediate wall hole portion 51, and the cement milk solidifies to form the intermediate wall concrete portion 52, thereby forming the intermediate wall 5 (see Figure 4(C) and Figure 8 steps 12 to 14).

[0035] Here, the excavation of the intermediate wall hole 51 in the intermediate wall 5 and the injection of cement milk are carried out before the cement milk for constructing the side wall concrete portion 42 in the side wall hole 41 is completely solidified and is still in a fluid state. In other words, the intermediate wall hole 51 in the intermediate wall 5 and the injection of cement milk into the intermediate wall hole 51 are carried out when the concrete portion of the side wall concrete portion 42 has not yet solidified and is in a liquid state and can be mixed with the cement milk that forms the intermediate wall 5.

[0036] This causes the side wall concrete portion 42 of the side wall 4 and the intermediate wall concrete portion 52 formed by solidification of the cement milk in the intermediate wall concrete portion 52 of the intermediate wall 5 to mix together, thereby integrating the side wall concrete portion 42 of the side wall 4 and the intermediate wall concrete portion 52 of the intermediate wall 5.

[0037] In the unit wall body B2, two intermediate walls 5 are formed between the side walls 4, 4 located on both sides of the intermediate wall 5 (see Fig. 1 and Fig. 2(A)-(C)), or one intermediate wall 5 is formed (see Fig. 2(D)). When two intermediate walls 5 are formed in the unit wall body B2, the two intermediate walls 5, 5 are formed so as to intersect with each other along the depth direction (up-down direction). Here, when excavating the intermediate wall hole portion 51 of the intermediate wall 5, an excavation guide device 6 may be used.

[0038] The structure and usage of the excavation guide device 6 will be described later. When there is one intermediate wall 5 in a set of unit wall bodies B2, the distance between the H-shaped steels 2, 2 of the parent piles B1, B1 on both sides of the unit wall body B2 is configured to be narrow. When there is one intermediate wall 5 in the unit wall body B2, this is often used when the retaining construction area A is relatively small.

[0039] The side walls 4 and intermediate walls 5 constituting the parent pile B1 and the unit wall body B2 are arranged as described above along the area boundary line Jx in the X direction of the earth retaining construction area A and the area boundary line Jy in the Y direction (see Fig. 2). The inner edge of the flange 21 of the H-shaped steel 2 of the parent pile B1 arranged on the X direction side of the projected corner To, in other words, the outer edge of the flange 21 located inward of the earth retaining construction area A, is located at the intersection of the area boundary line Jx and the area boundary line Jy (see Fig. 2).

[0040] Furthermore, the edge of the inner flange 21 of the H-shaped steel 2 of the parent pile B1 arranged on the Y-direction side of the protruding corner To, in other words, the edge of the flange 21 located inside the earth retaining construction area A located outside the earth retaining construction area A, is located at a position a predetermined distance away from the intersection of the area boundary line Jx and the area boundary line Jy. The inner flanges 21 of the H-shaped steel 2 of the parent pile B1 arranged along the area boundary line Jx and area boundary line Jy in the earth retaining construction area A are arranged so as to be aligned in a row along the area boundary line Jx and area boundary line Jy on which they are respectively arranged (see FIG. 2).

[0041] With respect to the H-shaped steel 2 of the parent pile B1 located on the area boundary line Jx side at the protruding corner To of the retaining construction area A, the side wall 4 located closest to the parent pile B1 on the area boundary line Jx side fits directly between both flanges 21, 21 of the H-shaped steel 2 along the area boundary line Jx (see Figure 2). In addition, the side wall 4 on the area boundary line Jy side located closest to the parent pile B1 on the area boundary line Jx side is arranged so as to incline toward the H-shaped steel 2 of the parent pile B1 on the area boundary line Jx side with respect to the linear row of other intermediate walls 5 and side walls 4, and fits between both flanges 21, 21 of the H-shaped steel 2.

[0042] As for the H-shaped steel 2 of the parent pile B1 located at the inside corner Ti between the area boundary lines Jx and Jy in the retaining construction area A, the web 22 of the H-shaped steel 2 is arranged at an angle of 45 degrees with respect to the X and Y directions (see Figs. 2(A) and (C)). The flanges 21, 21 of the H-shaped steel 2 of the parent pile B1 located at the inside corner Ti are configured to fit the side walls 4, 4 located closest to the inside corner Ti between the area boundary lines Jx and Jy.

[0043] Regarding the side walls 4 and intermediate walls 5 in the retaining construction area A described above, it is preferable that the diameter (outer diameter) of the approximately cylindrical intermediate wall 5 is equal to or larger than the diameter (outer diameter) of the approximately cylindrical side wall 4, and it is most preferable that the diameter (outer diameter) of the intermediate wall 5 is larger than the diameter (outer diameter) of the side wall 4. Furthermore, in the retaining construction area A, a gap may be formed between the side wall 4 arranged in the Y direction adjacent to the parent pile B1 at the projected corner part To and the H-shaped steel 2 of the parent pile B1. In this case, a supplementary side wall 4 may be added to fill the gap between the parent pile B1 and the side wall 4 (see Figures 2(A) and (B)).

[0044] Next, a method for constructing an earth retaining wall and the necessary equipment will be described. Before explaining the construction, the necessary equipment for constructing an earth retaining wall will be described. The equipment mainly used is a leaderless pile driver C, which is composed of a vehicle body 7 and an excavation device 8. The vehicle body 7 is a vehicle that can move on its own by having a main body 71 with a driver's cabin and a track 72, and the main body 71 is equipped with an extendable boom 73 (see FIG. 5).

[0045] The drilling device 8 includes a drilling drill 81, an auger 82 that rotates the drilling drill 81 in the circumferential direction of the axis, a tip drilling mechanism 83 attached to the tip of the drilling drill 81, and a loop head 84. The tip drilling mechanism 83 is replaceably attached to the drilling drill 81. A drilling guide device 6 may be provided above the tip drilling mechanism 83 as necessary (see FIG. 11).

[0046] The loop head 84 is formed with an outer diameter larger than the outer diameter of the screw-shaped tip excavation mechanism part 83 provided on the excavation drill 81, and a digging blade (not shown) is also attached to the lower end part (tip part) of this loop head 84. The loop head 84 is formed in a screw shape, and the soil dug up by the digging blade of the tip excavation mechanism part 83 and the digging blade of the loop head 84 are guided upward.

[0047] The loop head 84 and the tip drilling mechanism 83 are mounted on the same shaft, and this shaft is detachably attached to the drilling drill 81 via a mounting bolt. Although not shown in the figure, a loop material may be attached around the loop head 84, which may prevent the loop head 84 from coming into direct contact with the H-shaped steel 2 of the parent pile B1 during construction of the side wall hole 41.

[0048] Next, the construction of the earth retaining wall will be explained. To determine the area where the earth retaining wall will be constructed, an earth retaining construction area A is set, which is composed of straight line portions along the X and Y directions and multiple corners (see FIG. 2). As described above, the straight line portions in the earth retaining construction area A are the area boundary line Jx along the X direction and the area boundary line Jy along the Y direction. Then, an outside corner To and an inside corner Ti are set where the area boundary line Jx and the area boundary line Jy intersect.

[0049] The parent pile hole 1 is excavated at the area boundary line Jx and area boundary line Jy of the retaining construction area A by the drilling drill 81, loop head 84, and tip excavation mechanism unit 83 of the excavation device 8 (see steps 1 and 2 in Fig. 5). Next, cement milk is injected from the bottom to the middle of the total depth in the vertical direction of the parent pile hole 1 (see step 3 in Fig. 5). The cement milk is injected by spraying it from the loop head 84 and tip excavation mechanism unit 83 via a pump from the ground through the tubular drilling drill 81. The loop head 84 and tip excavation mechanism unit 83 are provided with a nozzle so that the cement milk can be sprayed.

[0050] Next, the H-shaped steel 2 is inserted into the pile hole 1, and the pile hole 1 is filled with the soil that was created when the pile hole 1 was excavated to form the pile B1 (see steps 4 and 5 in Figure 6). The piles B1 are embedded as accurately as possible into the vertical pile hole 1, and the upper part of the H-shaped steel 2 is set to protrude slightly from the opening of the pile hole 1. In this way, the piles B1 are constructed and placed at predetermined intervals along the area boundary line Jx and area boundary line Jy of the retaining construction area A (see step 6 in Figure 6).

[0051] Next, we move to the process of constructing the side wall 4. Specifically, a side wall hole 41 is excavated so that a part of the side wall 4 fits into the gap S between adjacent parent piles B1, B1 and between both flanges 21, 21 of each H-shaped steel 2, and a lower part of the side wall 4 intersects with the upper part of the cement milk injection part of the parent pile B1, that is, the part that becomes the concrete support part 3 when solidified (see steps 7 and 8 in FIG. 7).

[0052] Then, cement milk is injected into the side wall hole 41 to construct the cylindrical side wall concrete portion 42 (see steps 9 and 10 in Fig. 7). Such side walls 4 are constructed so as to fit into the gaps S between both flanges 21, 21 of all parent piles B1. At this time, a structure is formed in which parts of the side walls 4, 4 in the width direction fit into both gaps between both flanges 21, 21 on both sides of the width direction of the parent pile B1. Here, the steps of excavating the side wall hole 41 and injecting cement milk are performed when the cement milk constituting the concrete support portion 3 of the parent pile B1 is in a soft state before it hardens.

[0053] In the construction process of the side wall 4, the side wall hole 41 intersects with the parent pile hole 1 of the parent pile part B in the width direction in part. The parent pile hole 1 is backfilled with embankment on the top surface of the concrete support part 3, but since the embankment backfilled in the parent pile hole 1 is in an extremely soft and loose state, the cement milk injected into the side wall hole 41 flows into the parent pile hole 1 side, mixes appropriately with the backfilled embankment, and hardens into a mortar state. As a result, the side wall 4 and the parent pile B1 mix firmly together to form the wall body.

[0054] Next, the process proceeds to the step of constructing the central wall 5. First, an intermediate wall hole 51 is excavated between both side walls 4, 4 located between adjacent parent piles B1, B1 to the same depth as the side wall hole 41 of the side wall 4 and so as to intersect with the side wall hole 41 in the diametric direction (see steps 11 and 12 in FIG. 8). Next, cement milk is poured into the intermediate wall hole 51. When the cement milk solidifies in the intermediate wall hole 51, an intermediate wall concrete part 52 is formed, and the construction of the intermediate wall 5 is completed by intersecting a part of the side wall concrete part 42 of the side wall 4 in the width direction (see steps 13 and 14 in FIG. 8). Here, a drilling guide device 6 described later may be used for the construction of the intermediate wall 5.

[0055] Next, the drilling guide device 6 will be described. The drilling guide device 6 serves to position the tip drilling mechanism 83 when drilling the intermediate wall hole 51 with the drilling device 8 of the drilling drill 81, loop head 84, and tip drilling mechanism part 83 in the construction of the intermediate wall 5 (see FIG. 11). In addition, it serves as a guide to accurately maintain the traveling direction of the drilling drill 81, loop head 84, and tip drilling mechanism part 83 from the start of drilling.

[0056] That is, when the intermediate wall hole 51 is excavated by the excavation device 8, the excavation drill part 81 serves to excavate the intermediate wall hole 51 at an accurate position without approaching the intermediate wall hole 51 biasedly in the direction of the side wall hole 41 in the adjacent side wall 4. Furthermore, the blade material 63 of the excavation guide device 6 also serves to stir the soil and the injected cement milk within its movable range during the excavation work.

[0057] The excavation guide device 6 is composed of a guide body 61, two blade holding members 62, and two blade holding members 62 (see Figs. 9 and 10). The guide body 61 has a shaft support portion 61a, a connecting protrusion portion 61b, and a connected portion 61c. The two blade holding members 62 are attached to the shaft support portion 61a.

[0058] The connecting protrusion 61b serves to connect to the lower end of the drill 81, and has a circular or polygonal cross section. A connected hole 81a into which the connecting protrusion 61b is inserted is formed at the lower end of the drill 81. The connecting protrusion 61b is inserted into the connected hole 81a of the drill 81, and is fixed by a fastener 64 such as a bolt or nut. The connected portion 61c of the guide body 61 serves to connect the loop head 84 and the tip drilling mechanism part 83 of the drilling device 8 (see Figures 10(A) and (B)).

[0059] The blade retaining material 62 is composed of a substantially semicircular arch-shaped bearing portion 62a, a connecting plate portion 62b extending outward from both widthwise ends of the bearing portion 62a, and a blade attachment plate portion 62c extending radially from a predetermined position of the bearing portion 62a. The bearing portions 62a of the two blade retaining materials 62, 62 sandwich the shaft support portion 61a of the guide body 61 (see FIG. 9(A)).

[0060] The inner diameter of the circular inner circumference formed by symmetrically joining the two bearing portions 62a, 62a is set to be approximately equal to the outer diameter of the shaft support portion 61a. The connecting plate portions 62b, 62b are fixed to each other with fasteners 64 such as bolts and nuts, and both blade holders 62, 62 are rotatably attached to the shaft support portion 61a of the guide body 61. The connecting plate portion 62b and the blade attachment plate portion 62c are formed with bolt holes for fasteners 64 such as bolts and nuts.

[0061] The blade material 63 is attached so as to be replaceable with respect to the blade holding material 62. The blade material 63 has a substantially T-shaped cross section perpendicular to the longitudinal direction. The blade material 63 has bolt holes on one longitudinal side for fasteners 64 such as bolts and nuts for attachment to the blade attachment plate portion 62c.

[0062] The blade material 63 is fixed to the blade mounting plate portion 62c of the blade holder 62 via fasteners 64 such as bolts and nuts. Here, in the theory of connecting the blade mounting plate portions 62c, 62c, by arranging the bolt holes in the vertical direction, the fasteners 64 such as bolts and nuts are also arranged in the vertical direction, which reduces soil resistance during excavation work.

[0063] When both blade holding materials 62, 62 are attached to the shaft support portion 61a of the guide body 61, both blade attachment plate portions 62c, 62c are set to be located on an extension of the diameter of the circular cross section of both bearing portions 62a. In other words, both blade attachment plate portions 62c, 62c are provided to be approximately point-symmetrical with respect to the center of the cross-sectional diameter of the shaft support portion 61a, and the two blade materials 63, 63 attached to both blade attachment plate portions 62c, 62c also have a positional relationship that is approximately point-symmetrical.

[0064] The blade materials 63 are prepared in various different lengths in the longitudinal direction. Two blade materials 63 are attached to the excavation guide device 6. In the case where there are two intermediate walls 5 between adjacent parent piles B1, B1, each intermediate wall 5 is provided at a position offset from the center of both H-shaped steel beams 2, 2 between the adjacent parent piles B1, B1.

[0065] Therefore, the two blade materials 63, 63 are used with different lengths in the longitudinal direction. In other words, one intermediate wall 5 is constructed at a position offset toward one H-shaped steel 2 from the middle between the two H-shaped steels 2, 2, and the other intermediate wall 5 is constructed at a position offset toward the other H-shaped steel 2, so the lengths of the two blade materials 63, 63 are made different so that both tips can abut against both H-shaped steels 2, 2. In addition, when there is one intermediate wall 5 between adjacent parent piles B1, the intermediate wall 5 is located at the center of both H-shaped steels 2, 2 between adjacent parent piles B1, B1, and two blade materials 63 with the same length in the longitudinal direction are used.

[0066] The blade material 63 attached via the blade retaining material 62 attached to the guide body 61 can rotate on a horizontal plane together with the guide body 61 which rotates due to the rotation of the drilling drill 81, and when the blade material 63 abuts against the flange 21 of the H-shaped steel 2, the rotation stops together with the blade retaining materials 62, 62 (see Figure 11).

[0067] The tips of the two blade materials 63 of the drilling guide device 6 enter between the two flanges 21, 21 of the H-shaped steel 2 of the parent pile B1, and the tips of the blade materials 63 approach or abut against the flanges 21, 21 or the web 22 of the H-shaped steel 2. As the drilling drill 81 rotates, the drilling guide device 6 itself also tries to rotate, but when the blade materials 63 abut against the flanges 21, 21, the drilling guide device 6 rotates freely relative to the shaft support part 61a of the guide body 61, and the shaft center of the drilling drill 81 is maintained in a constant position by the H-shaped steel 2 of the adjacent parent piles B1, and the intermediate wall hole 51 in the intermediate wall 5 can be accurately drilled without being affected by the side wall hole 41 in the nearby side wall 4.

[0068] The use of the drilling guide device 6 will now be described. The drilling guide device 6 serves to excavate the intermediate wall hole 51 at an accurate position while maintaining the verticality during construction of the intermediate wall 5. The tip portions of the two blade members 63, 63 of the drilling guide device 6 are inserted into the gap S formed by both flanges 21, 21 and the web 22 of each of the adjacent H-shaped steels 2, 2 of the adjacent parent piles B1, B1.

[0069] At this time, the tip portions of both blade materials 63, 63 of the drilling guide device 6 are set so as to be able to come into contact with both flanges 21, 21 or the web 22 of the H-shaped steel 2. Then, drilling is started by the drilling drill 81, loop head 84, and tip drilling mechanism 83, and both blade materials 63, 63 use both H-shaped steels 2, 2 approximately like guide rails to perform accurate drilling work, and can perform the drilling work without being affected by the side wall hole 41 adjacent to the intermediate wall hole portion 51.

[0070] Also, although not shown, the upper part of the concrete support part 3 of the parent pile B1 and the lower part of the side wall 4 may be adjacent to each other without intersecting in the vertical direction. Even in this case, by injecting cement milk into the side wall hole 41, the cement milk flows into the backfilled soil above the concrete support part 3 of the parent pile hole 1 and turns into a mortar state, which solidifies, essentially integrating the parent pile B1 and the side wall 4. [Explanation of symbols]

[0071] 6...Drilling guide device, 61...Guide body, 61a...Axial support portion, connecting protrusion 61b, 62...Blade retainer, 62a...Bearing portion, 62b...Connecting plate portion, 62c...Blade mounting plate portion, 63...Blade material, drilling drill 81, connection hole 81a, 90…Intersection.

Claims

1. A drilling guide device is connected to a lower end of a drilling drill for drilling new pile holes for injecting cement milk into predetermined positions between a plurality of parent piles having H-shaped steel, The drilling drill has a lower end formed with a connection hole, and the guide body has a support portion and a connecting protrusion, and the connecting protrusion is inserted into the connection hole of the drilling drill and fixed with a bolt and nut. The blade holding material is composed of a semicircular arch-shaped bearing portion, connecting plate portions extending outward from both ends of the bearing portion in the width direction, and a blade attachment plate portion extending radially from a predetermined position of the bearing portion. The tips of the two blade materials fit into the U-shaped portion formed by the two flanges and web of the H-shaped steel of the parent pile, the tips of the blade materials abut against the flanges of the H-shaped steel and are close to the web, the blade materials attached via the blade retaining material attached to the guide body rotate on a horizontal plane together with the guide body which rotates in conjunction with the rotation of the drilling drill, and when the blade materials abut against the flanges of the H-shaped steel, their rotation stops together with the blade retaining material, and the blade materials of the excavation guide device stir soil and injected cement milk within their movable range during excavation work.

2. 2. The excavation guide device according to claim 1, wherein the blade material is prepared in a variety of different lengths in the longitudinal direction.

3. 3. The excavation guide device according to claim 1, wherein the two blade materials have different lengths in the longitudinal direction.

4. 3. The excavation guide device according to claim 1 or 2, wherein the two blade materials have the same length in the longitudinal direction.

Images