Method of building in core material

Abstract

To provide an installation method for core material allowing the core material to be efficiently installed in a removed space of an underground obstacle.SOLUTION: An installation method for core material to install the core material in a removed space of an underground obstacle comprises: an obstacle removal process removing the underground obstacle embedded in a caisson after cutting the underground obstacle with a tip bit of the caisson pressed in the underground; a mouth pipe forming process pulling up the caisson from an underground hole formed in a removed space of the underground obstacle and leaving a tip side of the caisson as a mouth pipe in the underground hole; and a core material installation process placing a core material guide on a head part of the mouth pipe to install the core member in the underground hole by using a core material guide.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a method for constructing a diaphragm wall for building a core material in the removal trace of a subsurface obstacle.

Background Art

[0002] When attempting to construct a subsurface wall surrounding a construction planned area to demolish an existing building and construct a new building, structures remaining underground such as the underground structure and foundation of the existing structure may become obstacles.

[0003] For example, in the method for constructing a diaphragm wall of Patent Document 1, after removing a subsurface obstacle by the all-casing method, a curable material is filled in the removal trace to backfill it, and a preceding columnar body is constructed. Then, this preceding columnar body is used as part of the diaphragm wall.

[0004] In such a case, when building a retaining wall by building a parent pile 1 into the removal trace of a subsurface obstacle S as shown in Fig. 10(a), generally the following procedure is adopted. First, a casing is pressed into the ground by the casing method, and the subsurface obstacle S taken into the casing is removed.

[0005] Next, as shown in Fig. 10(b), a backfill material B is filled in the removal trace and cured to backfill the removal trace. A hole for building the parent pile is drilled in the backfilled area using a boring machine such as an earth auger, and cement milk C is filled. After that, before the cement milk C hardens, the parent pile 1 is built in.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] According to the above method, the main pile 1 can be accurately installed at the removal trace of the underground obstacle S. However, when removing the underground obstacle S and installing the main pile 1, it is necessary to perform the drilling operation twice, etc., and the number of working steps is large and complicated. In addition, for the two drilling operations to be performed, different types of drilling machines must be adopted, and it takes time and effort to move the drilling machines in and out.

[0008] Also, for example, as shown in FIG. 10(c), when the installation positions of adjacent main piles 1 are narrow, when drilling a hole for installing the subsequent main pile 1 adjacent to the previously installed main pile 1, the drilling machine may come into contact with the previously installed main pile 1. In such a case, the main pile 1 cannot be installed by the above method.

[0009] The present invention has been made in view of such problems, and its main object is to efficiently install the core material at the removal trace of the underground obstacle.

Means for Solving the Problems

[0010] To achieve such an object, the method for installing the core material of the present invention is a method for installing the core material for installing the core material at the removal trace of the underground obstacle, which includes an obstacle removal step of cutting the underground obstacle with the tip bit of the casing pressed into the ground and then removing the underground obstacle taken into the casing, a mouthpiece tube forming step of pulling up the casing from the underground hole formed at the removal trace of the underground obstacle and leaving the tip side of the casing as the mouthpiece tube of the underground hole, and a core material installation step of installing a core material guide at the head of the mouthpiece tube and installing the core material into the underground hole using the core material guide.

[0011] The method for constructing the underground continuous wall of the present invention is characterized in that a casing holder is installed around the underground hole, and the mouthpiece tube is held by the casing holder.

[0012] According to the method for constructing a diaphragm wall of the present invention, the tip side of the casing used when removing underground obstacles is left in the underground hole as a mouthpiece pipe, and this mouthpiece pipe is used as a pedestal on which a core material guide used when building the core material is placed. Thereby, even when the diameter of the underground hole formed in the removal trace of the underground obstacle is sufficiently larger than the cross section of the core material, the core material can be accurately built into the planned position using the core material guide. As a result, it is possible to omit the operation of drilling a hole for building the core material after backfilling the removal trace of the underground obstacle as in the prior art.

[0013] In addition, if a large-diameter casing is adopted when removing underground obstacles, a plurality of core materials can also be built into the underground hole formed in the removal trace of the underground obstacle, significantly improving the working efficiency when building the core materials, and contributing to shortening the construction period and reducing the construction cost.

Effect of the Invention

[0014] According to the present invention, after removing the underground obstacle, the step of backfilling the removal trace and constructing a hole for building the core material can be omitted, and it becomes possible to efficiently build the core material in the removal trace of the underground obstacle.

Brief Description of the Drawings

[0015]

Figure 1

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Embodiments for Carrying Out the Invention

[0016] The present invention uses a casing used when removing underground obstacles to install a core material in the removal trace. The core material can be any long member installed underground, such as the main piles of a retaining wall, the core material of a continuous underground wall, an existing concrete pile or steel pipe pile forming a support pile, etc. Hereinafter, with reference to FIGS. 1 to 9, the case of installing the main pile 1 of the retaining wall will be taken as an example, and the details of the method for installing the core material will be described.

[0017] ≪≪≪Main Piles of Retaining Wall≫≫≫ As shown in FIG. 1(a), when constructing a new building N, a retaining wall 3 may be constructed so as to surround the construction target area. The retaining wall 3 is formed by driving main piles 1 such as H-shaped steel to a predetermined depth at a predetermined position designed in advance, for example, as shown in FIG. 1(b). Thereafter, it is constructed by providing a diaphragm 2a, a lateral sheeting 2b, and, if necessary, a cut beam or a pile driving (not shown).

[0018] At this time, when attempting to construct a new building N using the removal trace where the upper structure of the existing building has been removed, there may be a case where underground obstacles S such as underground structures and foundations remain underground. If these underground obstacles S are at the installation position of the main pile 1, after removing the vicinity including the part interfering with the main pile 1 among the underground obstacles S, the main pile 1 is installed in the removal trace.

[0019] ≪≪≪Step of Removing Underground Obstacle S and Providing an Underground Hole≫≫≫ The operation of removing such a subsurface obstacle S and installing the parent pile 1 of the retaining wall 3 at the removal site can be realized by the following procedure.

[0020] <<Obstacle removal process>> First, by using the all-casing method that utilizes the casing 11 attached to the boring machine 10 as shown in Fig. 2, the subsurface obstacle S at the planned installation position of the parent pile 1 is removed, and a subsurface hole H with its hole wall protected by the casing 11 as shown in Fig. 4(c) is constructed.

[0021] <<Boring machine>> The boring machine 10 may adopt any type as long as it is equipped with equipment applicable to the all-casing method. For example, a BG machine (manufactured by Bauer GmbH in Germany), known as a hydraulic multi-functional large-diameter boring machine, can be adopted. Hereinafter, the case of adopting the BG machine as the boring machine 10 will be taken as an example to explain its structure.

[0022] The boring machine 10 includes a traveling unit 12 equipped with crawlers, a base machine 13 rotatably provided on the traveling unit 12, and a leader 14 tiltably provided on a bracket provided on the base machine 13. A guide member 141 is provided on the front surface of the leader 14, and a top sheave 142 is provided at the upper end.

[0023] The guide member 141 extends in the longitudinal direction (vertical direction) of the leader 14 and guides the moving direction of the rotary drive device 16. The rotary drive device 16 is provided with a dreddler 161 at its lower end, and the casing 11 is connected to the dreddler 161. As shown in Fig. 2, the casing 11 includes a tip casing 11a having a tip bit 111 at its tip and a casing body 11b connected to the tip casing 11a.

[0024] On one side, a wire 15 is wound around the top sheave 142, and its tip is hanging down on the front side of the leader 14. Further, a kelly bar 17 is suspended from the tip of the wire 15 via a swivel joint 151. The kelly bar 17 is provided so as to penetrate through the rotary drive device 16 and the dretter 161, and an excavation attachment 18 such as an auger drill 18a or a hydraulic club hammer 18b as shown in FIGS. 4(a) and 4(b) can be attached to the tip thereof.

[0025] Both the above casing 11 and the excavation attachment 18 are structured such that rotational force is applied via the rotary drive device 16 and the dretter 161 that move up and down along the leader 14.

[0026] To remove the portion of the underground obstacle S that interferes with the planned installation position of the main pile 1 with the hole drilling machine 10 having such a configuration, first, as shown in FIG. 2, the casing 11 is positioned at a position surrounding the planned driving position of the main pile 1 set in advance. For positioning the casing 11, it is advisable to employ, for example, a scale iron plate 5 arranged on the ground surface.

[0027] ≪Scale Iron Plate≫ The scale iron plate 5 is composed of a substantially T-shaped iron plate having a through hole 51 of a size through which the casing 11 can be inserted, as shown in FIG. 7(a). This scale iron plate 5 is installed in advance on the ground surface such that the through hole 51 matches the arrangement position of the casing 11. Then, the hole drilling machine 10 is moved close to the scale iron plate 5, and position adjustment is performed by appropriate means so that the casing 11 is arranged at a position where it penetrates through the through hole 51 of the scale iron plate 5. Thereby, the casing 11 can be positioned at a position surrounding the planned driving position of the main pile 1.

[0028] Subsequently, as shown in Fig. 3(a), the casing 11 is rotationally press-fitted into the ground via the rotational drive device 16. Then, the casing 11 penetrates into the ground while cutting the underground obstacle S with the tip bit 111. And when the total length of the casing 11 is insufficient, the casing 11c is appropriately added to the casing 11 while the casing 11 is rotationally press-fitted into the ground.

[0029] For the addition work, as shown in Fig. 3(b), the added casing 11c is prepared at the material temporary storage place 4 provided near the base machine 13. Before and after this, the rotational press-fitting work of the casing 11 is temporarily stopped, and the connection between the upper end of the casing 11 and the dredger 161 is released. Next, the base machine 13 is rotated to move the dredger 161 to the material temporary storage place 4, and the head of the temporarily placed added casing 11c is connected to the dredger 161.

[0030] Subsequently, the base machine 13 is rotated again to move the added casing 11c connected to the dredger 161 above the casing 11 penetrating into the ground, and the lower end of the suspended added casing 11c is connected to the head of the casing 11. Such addition work and the rotational press-fitting work of the casing 11 by the rotational drive device 16 are repeatedly carried out until the tip of the casing 11 reaches the lower end of the underground obstacle S.

[0031] Next, the rotational press-fitting work of the casing 11 is temporarily stopped, the connection between the upper end of the casing 11 and the dredger 161 is released, the tip of the auger 17 located inside the dredger 161 is exposed, and as shown in Fig. 4(a), an auger drill 18a is attached to the tip. When the rotational drive device 16 is operated, a rotational force is transmitted to the auger drill 18a via the dredger 161. Therefore, with this auger drill 18a, the earth and sand and the underground obstacle S in the casing 11 are crushed and drilled.

[0032] Further, as shown in Fig. 4(b), the auger drill 18a is pulled out from the casing 11, and instead, a hydraulic club hammer 18b is attached to the kelly bar 17. Using this hydraulic club hammer 18b, the concrete pieces and earth and sand of the underground obstacle S crushed by the auger drill 18a are picked up and discharged. In such a procedure, the rotary pressing operation of the casing 11, the boring operation inside the casing 11, and the discharging operation of the concrete pieces and earth and sand are repeated at appropriate timings.

[0033] As a result, as shown in Fig. 4(c), the underground obstacle S at the driving position of the main pile 1 is removed, and in the removal trace, a underground hole H whose hole wall is protected by the casing 11 is constructed. Note that the auger drill 18a and the hydraulic club hammer 18b may be appropriately used according to the state of the underground obstacle S, the ground conditions, etc. Also, as the excavation attachment 18, other boring tools may be prepared and used.

[0034] ≪≪Mouthpiece Pipe Forming Process≫≫ After constructing the underground hole H whose hole wall is protected by the casing 11 in this way, as shown in Fig. 5(a), a curable filling material F is placed and filled into the underground hole H through the tremie pipe T, and the underground hole H is backfilled. The curable filling material F is not particularly limited, but in this embodiment, fluidized treated soil is adopted.

[0035] After backfilling the underground hole H with the curable filling material F, as shown in Figs. 5(b) and 5(c), before the curable filling material F hardens, while gradually pulling up the casing 11, the extended casing 11c exposed on the ground is sequentially removed and withdrawn. Then, the tip side of the casing 11 is left as the mouthpiece pipe 6 of the underground hole H.

[0036] In Fig. 5(c), the tip casing 11a and the casing body 11b connected thereto are left as the mouthpiece pipe 6, but depending on the ground conditions, a plurality of extension casings 11c may be left as part of the mouthpiece pipe 6. The operation of removing the extension casing 11c while gradually pulling up such a casing 11 and leaving the tip side as the mouthpiece pipe 6 of the underground hole H is performed using the casing holder 20.

[0037] ≪Casing Holder≫ As shown in Figs. 7(b) and 7(c), the casing holder 20 includes a holder body 21 installed on the ground surface around the casing 11, and a plurality of wedge members 22 inserted into the gap between the holder body 21 and the casing 11.

[0038] The holder body 21 has a ring shape as shown in Fig. 7(b), and its inner diameter is formed to be large enough to form a gap with the casing 11. Its structure may be an integral ring member, or for example, it may be composed of a pair of split members and formed to be assembled by fastening means such as bolts.

[0039] As shown in Fig. 7(c), the wedge member 22 is composed of a wedge body 221 and a locking ring 222, and a plurality of them are arranged at intervals in the circumferential direction of the casing 11. In Fig. 7(b), four wedge members 22 are provided at intervals in the circumferential direction, but the number may be any as long as it is at least 3 or more.

[0040] When it is desired to support the casing 11 using the above-described casing holder 20, with the holder body 21 placed at a position surrounding the casing 11 on the ground surface, the wedge body 221 of the wedge member 22 is inserted into the gap between the two. On the other hand, when it is desired to release the support of the casing 11, the wedge body 221 is pulled out using the locking ring 222. Note that the casing holder 20 is not limited to the above shape, and any configuration may be adopted as long as it has a structure capable of supporting the casing 11 in a suspended state within the underground hole H.

[0041] The operation of removing the upper part of the casing 11 and leaving the tip side as the mouthpiece tube 6 using such a casing holder 20 is carried out in the following procedure.

[0042] First, connect the head of the casing 11 that protects the hole wall of the underground hole H and the dredger 161. Before and after or simultaneously with these operations, install the holder body 21 at a position surrounding the casing 11 as shown in FIG. 7(b).

[0043] Next, as shown in FIG. 5(b), raise the rotary drive device 16 along the guide member 141 provided on the leader 14, and pull up the casing 11 until the entire spliced casing 11c is exposed above the ground. After that, insert the wedge member 22 into the gap between the lower spliced casing 11c and the holder body 21 arranged around it to support the casing 11.

[0044] In this state, disconnect the connection between the entire spliced casing 11c exposed on the ground, the dredger 161 connected to its upper end, and the spliced casing 11c (held by the casing holder 20) connected to its lower end. Then, after removing the exposed spliced casing 11c, connect the head of the spliced casing 11c held by the casing holder 20 and the dredger 161. After that, pull out the wedge member 22 and then pull up by the length of one portion of the spliced casing 11c. Repeat such operations sequentially.

[0045] In this way, leave the tip casing 11a corresponding to the lower part of the casing 11 and the casing body 11b connected thereto as the mouthpiece tube 6, and remove the other spliced casing 11c portions. The mouthpiece tube 6 remaining in the underground hole H is suspended and supported in the underground hole H via the casing holder 20 as shown in FIG. 5(c).

[0046] ≪≪Core material building-in process≫≫ After the above operations are completed, use the mouthpiece tube 6 as a gantry and install the core material guide 30 used when driving the parent pile 1 into the underground hole H as shown in FIG. 6(a).

[0047] <<Core Material Guide>> The core material guide 30 is a jig used to define the planar position with respect to the underground hole H when driving the main pile 1. As shown in Figs. 8(a) and 8(b), it includes a pair of vertical members 31, a pair of horizontal members 32, and a plurality of fixing brackets 33 for detachably fixing them. Its shape is assembled on the well girder in a plan view as shown in Fig. 8(a).

[0048] That is, a pair of vertical members 31 arranged at a separation interval slightly larger than the height of the main pile 1 are placed on the upper parts of a pair of horizontal members 32 arranged at a separation interval slightly larger than the flange width of the main pile 1. Then, by fixing both of them with the fixing brackets 33, an opening 34 having a cross-section substantially the same as that of the main pile 1 is formed, and this opening 34 is used as a guide when driving the main pile 1.

[0049] The opening 34 serving as a guide when driving the main pile 1 can be arranged at any position in the plan view in the underground hole H by appropriately adjusting the positions of the pair of horizontal members 32 with respect to the mouthpiece pipe 6 and the positions of the pair of vertical members 31 with respect to the pair of horizontal members 32. Figs. 8(a) and 8(b) give an example of the case where the main pile 1 is driven at a position where the axis coincides with the axis of the underground hole H.

[0050] Note that the core material guide 30 is not limited to the above configuration as long as it can form the opening 34 serving as a guide when driving the main pile 1. Also, in Figs. 8(a) and 8(b), angle steel is used for the vertical members 31, H-shaped steel is used for the horizontal members 32, and clamping brackets such as clamps are used for the fixing brackets 33. However, any long members may be used for the vertical members 31 and the horizontal members 32, and any member configuration may be adopted for the fixing brackets 33 as long as it can detachably fix the vertical members 31 and the horizontal members 32.

[0051] Using such a core material guide 30, the operation of driving the anchor pile 1 into the ground hole H is carried out according to the following procedure. First, as shown in Fig. 6(a), the core material guide 30 is installed on the mouthpiece pipe 6, and the arrangement position of the opening 34 is aligned with the planned driving position of the anchor pile 1. Next, as shown in Fig. 6(b), the Kelly bar 17 provided at the tip of the wire 15 provided in the boring machine 10 is removed, and the anchor pile 1 is installed and suspended above the ground hole H.

[0052] Then, as shown in Fig. 6(c), using the core material guide 30, the anchor pile 1 is lowered and driven into the ground hole H while being suspended. After that, before the curable filling material F hardens, the orientation and height of the anchor pile 1 are adjusted, and the position of the anchor pile 1 is fixed using a jig as appropriate. After that, the core material guide 30, the mouthpiece pipe 6, and the casing holder 20 are removed, and the vicinity of the ground surface of the ground hole H is backfilled as necessary.

[0053] As described above, in the method of driving the core material, the tip side of the casing 11 employed when removing the underground obstacle S is left in the ground hole H as the mouthpiece pipe 6, and this mouthpiece pipe 6 is used as a base for placing the core material guide 30 used when driving the anchor pile 1. Thereby, even when the diameter of the ground hole H formed at the removal trace of the underground obstacle S is sufficiently larger than the cross-section of the anchor pile 1, the anchor pile 1 can be accurately driven to the planned driving position using the core material guide 30.

[0054] In addition, when driving the anchor pile 1, it is possible to omit the operations such as backfilling the removal trace of the underground obstacle S and then boring the hole for driving the anchor pile 1, which were carried out in the prior art, contributing to shortening the construction period and reducing the construction cost.

[0055] Furthermore, when removing the underground obstacle S, if a boring machine 10 applicable to a large-diameter casing 11 is adopted, a plurality of main piles 1 can be driven into the large-diameter underground hole H formed in the removal trace of the underground obstacle S as shown in Fig. 9(a), and the working efficiency can be further improved. The procedure is as follows: First, as shown in Fig. 9(b), among the two main piles 1, the core material guide 30 is adjusted and arranged so that the opening 34 is located at the planned installation position of the first main pile 1, and the first main pile 1 is driven in with this opening 34 as a guide.

[0056] Next, as shown in Fig. 9(c), the core material guide 30 is adjusted and arranged so that the opening 34 is located at the planned installation position of the second main pile 1, and the second main pile 1 can be driven in. In this way, it is possible to efficiently drive in the main piles 1 under any construction conditions, such as when the driving positions of adjacent main piles 1 are narrow.

Explanation of Reference Numerals

[0057] 1 Main pile (core material) 2a Belly jack 2b Lateral sheeting 3 Retaining wall 4 Material temporary storage area 5 Scale iron plate 51 Through hole 6 Mouthpiece pipe 10 Boring machine 11 Casing 11a Tip casing 11b Casing body 11c Extended casing 111 Tip bit 12 Traveling part 13 Base machine 14 Leader 141 Guide member 142 Top sheave 15 Wire 16 Rotation drive device 161 Dredgerman 17 Kelly bar 18 Excavation attachment 18a Auger drill 18b Hydraulic Club Hammer 20 Casing Holder 21 Holder Body 22 Wedge Member 221 Wedge Body 222 Locking Ring 30 Core Material Guide 31 Vertical Member 32 Horizontal Member 33 Fixture 34 Opening T Tremey Pipe F Hardening Filling Material (Filling Material) N New Building B Backfill Material C Cement Milk

Claims

1. A method for installing a core material into the excavation trace of a subsurface obstacle, comprising: an obstacle removal step of cutting the subsurface obstacle with a tip bit of a casing pressed into the ground and then removing the subsurface obstacle taken into the casing; a mouthpiece pipe formation step of pulling up the casing from the subsurface hole formed in the excavation trace of the subsurface obstacle and leaving the tip side of the casing as a mouthpiece pipe at the mouth of the subsurface hole; a core material installation step of installing a core material guide at the head of the mouthpiece pipe and installing the core material into the subsurface hole using the core material guide. A method for constructing a continuous diaphragm wall in the ground, characterized by comprising the above steps.

2. In the method for constructing a continuous diaphragm wall according to Claim 1, a casing holder is installed around the subsurface hole, and the mouthpiece pipe is held by the casing holder. A method for constructing a continuous diaphragm wall in the ground, characterized by this.

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