JPH02266012A - Consolidating method for soft ground - Google Patents

Abstract

PURPOSE:To make thorough consolidation possible and to improve work efficiency with reduced materials and work processes by constructing consolidated ground of multicircular consolidation layers with a plurality of earth augers that are employed by turns from larger-bore machines to smaller-bore machines. CONSTITUTION:Excavation is made deep with a large-bore earth auger 8 with the consolidation center 16 being made the center of excavation end soft soil 9 is removed therefrom. The soft soil 9 at the lower and and at the peripheries of the auger 8 is consolidated with consolidating material 6 such as pit send or the like by reversing the auger 8. When resistance is made to the rotation of the auger 8, throwing-in of the consolidating materiel 6 is stopped and the auger 8 is pulled out. Then the excavation is made again with an earth auger 8' having a bore smaller than the auger 8 and after this, consolidation is made with the consolidating materiel 6 thrown into the peripheries of a spiral blade 10 by reversing the auger 8'. Similar processes are repeated and consolidation is further made by using by turns earth augers 8'', 8'''... having bores smaller than preceding machines. Thereby consolidated ground is formed of multicircular consolidated layers.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an improvement in a ground consolidation method when constructing structures such as pillars and manholes on soft ground.

<Concerning the conventional technology> To explain the conventional technology, first, as shown in Fig. 1 (A), for example, in the case of a pole, it is possible to prevent a fixed depth or inclination, and as shown in Fig. 1 (B), it is Draw contours 1 to (4) widely around (2) and up to the buried depth of the utility pole, and then
As shown in figure (C), the pillar hole (5
), and after laying a cracked stone (],) at the bottom of the pole and erecting the pole on top of it, fill the area around the utility pole (2) with compacted material such as shiiyama sand (6). Measures such as filling the area around the pillars in a funnel-shaped manner were used.

When constructing manholes, etc., the same method as the above-mentioned Tobaba is used.

In addition, the applicant is Jikoko 61. -18608 provides a sand pile construction method as a soft ground improvement method, and as shown in Figure 1 ([]), the earth auger (15) is used to excavate and while it is rotated in the opposite direction, the ground improvement material (mountain sand) is used. , gravel, etc.) (6) is also used to consolidate the soft layer (9).

<Problems to be solved by the invention> Figure 1 (A
), since the ground around the utility pole (2) is not consolidated, the utility pole (2) naturally slopes and sinks, and with the method shown in Figure 1 (B), the concrete for foot protection (4) is not consolidated. It is necessary to support the utility pole (2) by some means during the curing period of concrete 1-(4), which requires a large amount of concrete, and in the case of Figure (C), the part near the ground surface is 111 The area around the buried part of the utility pole (2), which has been reinforced with sand or other filler (6), is hardly consolidated, so there is no supporting pressure and the pole naturally tilts or sinks, as shown in Figure 1 (A). Also, with the method shown in Figure 1 (1), there is a problem that the center of consolidation (consolidation core), that is, the part of the earth auger remains unconsolidated. In the case of draining water from soft ground and consolidating it, there is a problem that even if a structure is built on sand piles, the water will gradually accumulate again and the structure will sink or slope.The present invention solves these problems. This is an attempt to resolve the issue.

(b) Regarding the structure of the invention (Means for solving the problems) The present invention adopts the following method in order to solve the problems of the conventional construction method as described in (2) below.

That is, using the consolidation core (16) as the excavation core, excavate to the required depth with a large diameter earth auger (8) to remove soft soil (9), and then remove mountain sand, etc. while rotating the auger (8) in the opposite direction. Consolidated material (6) is put around the ass auger (8) to remove the lower part of the tip of the auger (8) and the soft upper part (9) of the surrounding area.
) to consolidate. Fluctuations (resistance) in the rotation of the auger (8)
If this is seen, stop feeding the compacted material (6) and pull out the auger (8).
) remains unconsolidated, so here we use a smaller diameter earth auger (8') than a large diameter earth auger (8).
Then, while rotating the ocher (8") in the opposite direction: 3. Feed the consolidation material (6) around the spiral blade (10) and consolidate it. In the same way, use the earth auger with a smaller diameter. If it is consolidated using
11) is constructed.

The consolidation range may be wide or narrow depending on the type or size of the building, but if the diameter area of the large-diameter earth auger (8) initially used is insufficient for the area of the consolidated ground, the area of the consolidated ground that has been consolidated first is (11) is the center and around it, the area of consolidation influence (14) and the consolidated ceric acid layer (12') at the center.
Multiple circular consolidated ground (11') that intersect with each other.
to expand the consolidation range.

<Regarding the operation and effects of the invention> Since the present invention has the above-described configuration, FIG. 2(A)
As shown in , the large-diameter earth auger (8) has a spiral blade (10) that is small compared to its diameter.
The secondary circular consolidation layer (12) formed around 8) is thin, and a consolidation layer (12') is formed on the outside of the layer (12), which reduces the consolidation layer.

When the compaction by the large-diameter earth auger (8) is completed, the auger (8) is pulled out, and earth augers (8'...) with smaller diameters are sequentially used to perform the second process in the same manner as described above. Tertiary circular consolidation layer (]3.13'...
・) is formed, and finally, the compaction material (6) is fed in using the earth auger of the smallest diameter to form the final circular compaction layer, the compaction is completed, and the auger is pulled out.

In such a case, the consolidated layer (13'-') formed sequentially from the second consolidated layer (13) has a deconsolidated layer (12') on the outside thereof.
) are not formed, and all are completely consolidated, and a completely consolidated consolidated ground (11) is formed.

In addition, if a wide area of consolidated ground is required, as shown in Figure 3, the first consolidated ground (11) is the center and around it, the area of consolidation influence (14) is at least the consolidated silicic acid layer (+2
If the consolidated ground (l]') is constructed using the same method as described above with the position where the layers overlap each other as consolidation cores (1, 6'), the consolidated silicic acid layer (12) of the circular consolidation layer (12) 12") can be completely consolidated and the required area of consolidated ground can be obtained. Furthermore, the part where the last small-diameter earth auger is pulled out is a small-diameter opening [21", but normally there is no problem with construction work. Alternatively, the hole may open naturally due to lateral pressure, and if deemed necessary, mortar may be poured into the hole to open the hole.

The ground consolidated by the present method uses an earth auger, so it is possible to consolidate the soft ground (9) at a considerable depth, and the area of consolidation can be freely expanded, and the degree of consolidation can be made uniform. be. Therefore, there is no need for the conventional method of cross-section timbers (3), large amounts of concrete h (4), or supporting means during curing, and there is no need for the work of ramming mountain sand as shown in Figure 1 (C). The earth auger excavation part does not remain as a large opening (unconsolidated part) as in the case of FIG. However, it is very efficient to consolidate the required area in one work, and even if you erect a pillar or construct a manhole etc. on the consolidated ground, there will be sufficient supporting side pressure, etc. Q44, and the structure will not sink or tilt. No other inconveniences will occur.

[Brief explanation of drawings]

FIG. 1(A) to FIG. 1(I) are explanatory diagrams showing a conventional method for compacting the ground when constructing a structure on soft ground, and for preventing the structure from sinking and tilting. Note (E)
shows the state in which the earth auger in (D) is pulled out. FIG. 2 is an explanatory view of the method of the present invention, in which (A) is an explanatory side view of the formation of the first circular consolidated layer, and (B) is an explanatory side view of the formation of the second and subsequent circular consolidated layers. (C) is a plan view of the consolidated ground, and (D) is an explanatory longitudinal cross-sectional view thereof. FIG. 3 is an explanatory plan view when the consolidated ground expansion method is implemented. (])... Split chestnut stone (2)... Utility pole (3)... Square lumber (4)... Concrete 1~ (5)... Pole erection hole (6)... Consolidation hole (7)... ...Earth auger (Fig. 1 (D)) (
8, 8')... Earth auger (9)... Soft layer (soil) (10)... Spiral blade (11, 11')... Consolidated ground (12)... - Secondary circular consolidation layer (12') ... Consolidation sentence reduction (13, 13') Second and third consolidation layers (14)...
・Consolidation influence range (15)...Earth auger (Fig. 1 (D)) (1
6) Consolidation core/Drilling core (17) Consolidation effective range (18) Consolidation core (Drilling core)

Claims (2)

[Claims] (1) In the same excavation core, a large-diameter earth auger is sequentially changed to a small-diameter earth auger, and consolidation material is put in and consolidated around each earth auger each time, creating a consolidated ground with multiple circular consolidation layers. A method of consolidating soft ground characterized by comprising: (2) Centering on the consolidated ground consolidated by the method described in claim (1) above, a plurality of multi-circular consolidated grounds are constructed around the consolidated ground by intersecting at least the consolidation layer reduction layer within the area affected by the consolidation. A method of compacting soft ground, which is characterized by expanding the range of compaction.