JPH04350219A - Sheathing construction method - Google Patents

Abstract

PURPOSE:To construct a firm sheathing wall while preventing a facility from becoming a large scale. CONSTITUTION:A hole 2 is bored with the screw 3 of an auger to the depth where a hole wall is not collapsed while a solidifying material 4 is injected. After the solidifying material 4 is injected into the hole 2, the screw 3 is inserted into the hole 2 for excavation to the preset depth, the forward rotation of the screw 3 is maintained for the required period at the specific excavation position, the excavation soil and solidifying material are stirred and discharged, then the screw 3 is extracted from the hole 2, and the hole 2 is deepened by a series of actions. The solidifying material 4 is injected into the hole 2, and the ground is excavated to the target depth. When the target depth is attained, the forward rotation of the screw 3 is maintained for the required period, then the screw 3 is rotated reversely, the screw 3 is extracted from the hole 2 while the discharged soil 5 and solidifying material 4 are returned into the hole 2, and a pile-shaped hardened body 6 is obtained. The above processes are repeated to construct a sheathing wall.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earth retaining method mainly applied to constructing earth retaining walls in shallow ground.

0002

[Prior Art] Conventionally, as well-known, the sheet pile method, column row method, or continuous wall method have been mainly used as earth retaining methods, but especially when the excavation depth is small, (
(b) The so-called horizontal sheet pile construction method, in which the wall is formed using H, I-shaped steel and wooden boards, (b) The sheet pile construction method, in which steel sheet piles are driven into the soil, or (c) The soil pile column construction method is used, in which a slurry-like solidification material is mixed with the local soil and reinforcing material is added to create columns.

0003

[Problems to be Solved by the Invention] However, since the above-mentioned concrete horizontal sheet pile construction method mainly involves hand digging, the construction speed is slow, and it is difficult to avoid loosening the back ground, so water-stopping properties cannot be expected. There is this inconvenience. Also,
The sheet pile construction method has disadvantages in that it becomes uneconomical if the steel sheet piles are buried, and the back ground becomes loose when the steel sheet piles are pulled out. Furthermore, the soil pile column construction method includes:
Since a slurry or mortar plant is required, there is a problem in that the equipment must be large-scale. In addition, when using a slurry-like solidifying material, it is not only difficult to ensure high strength, but also because water is mixed in, which is disadvantageous to the strength development of the hardened product.
There is also the problem that more solidifying material is required to obtain the same strength than when using powdered material.

[0004] The present invention aims to solve all of the above-mentioned problems.

[0005]

[Means for Solving the Problems] In order to achieve the above objects, the present invention provides the following (a), (b), (c),
The method is characterized in that the steps (d) and (e) are repeated in sequence to form pile-like hardened bodies in columnar rows in the ground.

(a) A hole drilling machine having stirring and discharging functions is operated while being guided by a positioning ruler, and a hole is drilled while introducing a soil solidifying material into the surface layer of the ground to a depth where the hole wall does not collapse.

(b) After putting the soil solidification material into the hole, insert the drilling part of the hole drilling machine into the hole and drill to a specific depth, and keep drilling at the specific digging position for the required time. The hole is deepened by maintaining the normal rotation of the machine to agitate and discharge the excavated soil and solidified material, and then removing the borehole from the hole once or multiple times.

(c) A soil solidifying material is put into the hole from which the drilling machine has been pulled out, and the drilling section is inserted into the hole again to drill to the target depth.

(d) When the target depth is reached, after maintaining the normal rotation of the drilling machine for the required time, the drilling machine is reversed and the discharged soil and solidified material are returned to the hole. The hole drill is pulled out of the hole to obtain a pile-shaped hardened body.

(e) After completing the steps (a) to (d) above, move the guide position by the positioning ruler to the side by a distance approximately corresponding to the diameter of the pile-shaped hardened material, and then move it again. The step (a) is started.

[0011]

[Operation] In the above-mentioned step (a), the ground solidifying material is mixed into the discharged soil, and a cut hole for introducing the ground solidifying material is formed. Then, in step (b), the hole is deepened, and at this time, the work of mixing a soil solidifying material into the local soil and the reinforcement of the hole wall are performed simultaneously. In other words, if a hole is excavated to a specific depth with soil solidification material injected into the hole, and then the excavator is kept in normal rotation for the required period of time, the local soil and the ground solidification material that was previously introduced are stirred and mixed. It is ejected out of the hole in a state where it remains intact. Further, at this time, a portion of the soil solidification material is attached to the hole wall, so that the hole wall is reinforced. Therefore, even if the hole drilling machine is pulled up to newly introduce soil solidification material into the hole, the hole wall is prevented from collapsing. Then, in step (c), the hole is reinforced and dug to the target depth, and in step (d), the excavated soil is remixed by reversing the drilling machine and backfilled into the hole while being compacted. As mentioned above, this discharged soil is mixed with a soil solidifying agent. Therefore, over time, the soil solidifying material causes a hydration reaction and fixes the soil particles, forming a pile-shaped hardened body in the backfilling area. Then, in step (e), the guide position by the positioning ruler is moved to the side by a certain amount, and the step (a) is started again.

[0012] By repeating each of the above steps, columns of pile-shaped hardened bodies are created.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

First, as shown in FIG. 1, a predetermined amount of soil solidifying material 4 is poured into the surface layer of the ground 1 while a hole 2 is drilled to a depth I at which the hole wall 2a does not collapse. This drilling work is performed using a general-purpose screw type drilling machine. That is, the hole 2 is formed in the ground 1 by rotating the screw 3, which is the hole drilling part of the hole drilling machine, in the direction of the arrow X and lowering it at a predetermined speed in the axial direction. At this time, a predetermined amount (for example, 20
0 kg) of soil solidifying material 4 is uniformly poured into the hole being drilled. By doing so, a predetermined amount of the ground solidifying material 4 can be mixed into the discharged soil. In addition,
The hole drilling operation by the hole drilling machine is performed using a positioning ruler 10 as described later.

Next, as shown in FIG. 2, a ground solidifying material 4 is poured into the hole 2. The ground solidifying material 4 is a solidifying material whose main materials are gypsum, blast furnace slag, and ordinary Portland cement, with the addition of halogen compounds or sulfates as hardening accelerators as needed and mixing well. It is commercially available as ESC (trade name; manufactured by Osaka Cement Co., Ltd.). That is, this solidifying material 4 has a mixing ratio of gypsum, blast furnace slag, and ordinary Portland cement as the main materials: gypsum 15 to 60 (wt%), blast furnace slag 20 to 60 (wt%), and ordinary portland cement. 10 to 50 (wt%), and grind and mix them so that the specific surface area is 4500 cm2/g or less, or grind and mix them with a curing accelerator added to 5 (wt%) or less. It has water absorption, swelling and hydraulic properties. The amount of the ground solidifying material 4 to be added is the ratio of the set addition amount (Kg/m3) to the amount of undischarged soil, that is, the portion of soil from depth I to depth II.

As shown in FIG. 3, the screw 3 of the hole drilling machine is again inserted into the hole 2 into which the soil solidification material 4 has been introduced, and is lowered while rotating normally in the direction of the arrow X to reach the depth II.
(For example, dig to GL-5m). And depth II
When reaching , the descent of screw 3 is stopped, but
The forward rotation state of the screw 3 is maintained as it is. At this time, the previously introduced solidification material 4 and the excavated soil 5 are further mixed and are sequentially discharged out of the hole 2. Then, when the soil 5 is no longer discharged, the screw 3 is inserted into the hole 2.
Pull it out. In addition, when digging the screw 3,
When the screw 3 is rotated forward at a certain position to mix and discharge the soil 5 and the solidifying material 4, a part of the solidifying material 4 is transferred to the hole wall 2.
It will be attached to a. Therefore, the hole wall 2a is reinforced, and even if the screw 3 is pulled out of the hole 2, the hole wall 2a is
A will never collapse.

Next, as shown in FIG. 4, a ground solidifying material 4 similar to that described above is poured into the hole 2 which has been dug down to depth II. In this case, the input amount is from depth II to depth III.
Set addition amount for the soil volume of the part (Kg/m3
) (for example, 200 kg/m3).

In this way, as shown in FIG. 5, the screw 3 of the hole drilling machine is again inserted into the hole 2 into which the soil solidification material 4 has been introduced, and is lowered while rotating normally in the direction of the arrow X to reach the depth II.
Excavate to I (for example, GL-7m). Then, when the depth III is reached, the descent of the screw 3 is stopped, but the forward rotation state of the screw 3 is maintained as it is. At this time, the soil solidification material 4 introduced at the stage shown in Figure 4
and the excavated soil 5 are further mixed and sequentially discharged out of the hole 2.

[0019] The time required in this way (about 1 to 3 minutes)
After rotating the screw 3 in the normal direction, the screw 3 is rotated as shown in FIG.
As shown in , the mixture of soil 5 and soil solidification material 4 discharged out of the hole 2 is sequentially returned by reversing the direction of the arrow Y. At that time, the screw 3 is pulled up at a slow speed. As a result, the soil 5 and soil solidification material 4 returned into the hole 2 are further mixed and compacted. The degree of compaction can be controlled by the load of the screw drive device, etc.

Then, as shown in FIG.
When the soil 5 is completely pulled up from the hole 2, the soil 5 is poured into the hole 2.
The mixture of and soil solidification material 4 is completely filled. However, if this is left as it is, the ground solidifying material 4 reacts and exhibits a hardening effect over time, and a pile-shaped hardened body 6 is created. The self-supporting depth of the hole wall and the excavation depth for each construction stage will be determined through preliminary test excavation.

At the stage where the pile-shaped hardened body 6 has been created in this way, the guide position of the positioning ruler 10 is moved laterally by a distance L slightly shorter than the diameter of the hardened body 6, and then, the guide position is moved from the beginning again. Returning to each process mentioned above (Fig. 1~
Repeat Figure 7). The positioning ruler 10 is shown in FIGS. 10 to 12.
As shown in the figure, a rectangular frame 11 placed on the ground;
A guide tube 12 slidably attached to the frame 11,
The guide tube 12 is provided with a fixing mechanism 13 for fixing the guide tube 12 at a predetermined position on the frame 11. The guide tube 12 has an inner diameter corresponding to the outer diameter of the screw 3 of the hole drilling machine, and a tongue portion 12a provided at the upper end thereof is connected to the frame 11.
The rectangular flange 12b protruding from the outer periphery is brought into sliding contact with the upper surface 11a of the frame 11, and the frame 11 can be slid in the longitudinal direction thereof. Further, the fixing mechanism 13 includes a plurality of semicircular grooves 14 carved on the inner surface 11b of the frame body 11, and semicircular grooves 15 corresponding to the semicircular grooves 14 of the rectangular cylinder portion 12b of the guide tube 12. and a locking pin 16 that is removably installed between the opposing semicircular grooves 14 and 15. The interval between the semicircular grooves 14 is set to a value that allows the fixed position of the guide cylinder 12 relative to the frame 11 to be moved by the distance L. However, the guide tube 12
is fixed at a specific position, and each step (Figs. 1 to 7) is performed once while guiding the screw 3 with this guide cylinder 12. After that, the fixed position of the guide cylinder 12 is moved by a distance L. The frame body 11 is moved in the longitudinal direction and the above steps are performed again. By repeating this process, as shown in FIGS. 8 and 9, pile-shaped hardened bodies 6 are formed in column rows in slightly different states, and the retaining wall 1
7 is formed.

[0022] In the above embodiment, the series of operations of charging the soil solidifying material into the hole → excavating with the screw auger → stirring and removing soil by normal rotation of the screw → pulling the soil out of the hole with the screw is carried out in one step. Although a case has been described in which the process is carried out repeatedly, the present invention is not necessarily limited to such a case. That is, if the target depth is relatively deep, the series of operations described above may be repeated multiple times.

[0023] Also, the soil solidifying material is of course not limited to those mentioned above; for example, various materials such as ordinary Portland cement and blast furnace cement can be used.

[0024]Although the above embodiments have been described using a screw-type hole-drilling machine, any type of hole-drilling machine can be used as long as it performs the same or better role. good.

Further, the configuration of the positioning ruler is not limited to the above-mentioned configuration, and various modifications can be made without departing from the spirit of the present invention.

[0026]

[Effects of the Invention] Since the present invention has the above-described structure, the following effects can be obtained.

First, since construction is carried out using an excavator,
The construction speed is much faster than the main pile horizontal sheet pile method, which is mainly done by hand.

Moreover, the cured product according to the present invention has, for example,
It is possible to exhibit a uniaxial compressive strength of about several Kgf/cm2 to 60 Kgf/cm2, and the rigidity is high, displacement is small, and the back ground is rarely loosened.

[0029] In addition, it is possible to form the earth retaining wall using a general-purpose excavator, and the solidification material can be used in powder form, so there is no inconvenience that the equipment becomes large-scale. High-strength earth retaining walls can be constructed using a relatively small amount of solidification material.

Furthermore, since each cured body is created using a positioning ruler, there is no misalignment of each cured body with respect to each other, and high water-stopping properties can be ensured by providing a lapped portion.

[0031] According to the present invention, it is also possible to perform construction work such as lining, cutting, and earth anchoring.

[Brief explanation of drawings]

FIG. 1 is a process explanatory diagram showing one embodiment of the present invention.

FIG. 2 is a process explanatory diagram of the same example.

FIG. 3 is a process explanatory diagram of the same example.

FIG. 4 is a process explanatory diagram of the same example.

FIG. 5 is a process explanatory diagram of the same example.

FIG. 6 is a process explanatory diagram of the same example.

FIG. 7 is a process explanatory diagram of the same example.

FIG. 8 is a sectional view showing the earth retaining wall of the same example.

FIG. 9 is a cross-sectional view taken along line BB in FIG. 8;

FIG. 10 is a plan view showing the positioning ruler of the same embodiment.

FIG. 11 is a front view of the same.

FIG. 12 is a perspective view of the same.

[Explanation of symbols]

1...Ground 2...hole 3... Excavation part (screw) 4...Ground solidification material 5...Soil 6...Hardened body 7...Reinforcement steel material 10...Positioning ruler 11...Frame body 12...Guide cylinder

Claims (1)

[Claims] Claim 1: The following (a), (b), (c), (d), (
An earth retaining method characterized by sequentially repeating the step e) to create pile-like hardened bodies in columnar rows in the ground. (a) A hole drilling machine having stirring and discharging functions is operated while being guided by a positioning ruler, and a hole is drilled while introducing a soil solidifying material into the surface layer of the ground to a depth where the hole wall does not collapse. (b) After putting the soil solidification material into the hole, insert the drilling part of the hole drill into the hole and drill to a specific depth, and keep the hole drill at the specific digging position for the required time. The excavated soil and solidification material are stirred and discharged while maintaining the rotating state.
Thereafter, the hole is deepened by performing a series of operations such as removing the hole drill from the hole once or multiple times. (c) Inject soil solidification material into the hole extracted by the drilling machine,
Insert the drilling part of the drilling machine into the hole again and drill to the target depth. (d) At the stage when the target depth is reached, after maintaining the normal rotation state of the drilling machine for the required time, the drilling machine is reversed and the discharged soil and solidified material are returned to the hole while the drilling machine is being drilled. The pile-shaped cured product is obtained by pulling the machine out of the hole. (e) After completing the above steps (a) to (d), move the guide position of the positioning ruler to the side by a distance approximately corresponding to the diameter of the pile-shaped hardened material, and then repeat the steps ( Start a).