JPH11222849A - Structure of diaphragm wall and excavating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the structure of a diaphragm wall, in which the degree of freedom of a design is increased and strength can be set easily in response to stress, and an excavating. method. SOLUTION: The structure of the diaphragm wall has column wall sections 2, in which a plurality of column bodies 1,... are juxtaposed continuously in a row in a plan view and reinforcing column sections 3 having axial centers 3 at places passing the joining sections P of the adjacent column bodies 1, 1 on the plan view while being formed so that the column wall sections 2 and parts are superposed mutually. The reinforcing column sections 3 are disposed on one surface sides of the column wall sections 2 and on every other joining section P of the joining sections P of a plurality of the column bodies 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an underground wall such as a mountain retaining wall or a water blocking wall, and a method of excavating a ground.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 10, a method of excavating a ground c with a multi-screw excavator a having three earth augers b arranged in a line is disclosed in Japanese Patent Publication No. 62-54929. It is disclosed in gazettes and the like.

That is, as shown in FIGS. 10 and 11 (a), the ground c is excavated by three rotating earth augers b, and solidified from the earth augers b. by mixing and drilling soil while ejecting a liquid to form a borehole f ₁ of the first run. The borehole f ₁ is partially made of the longitudinal hole of three mutually overlap each other g .... Next, as shown in FIG. 11 (b), At a plan view, by a predetermined distance apart on a horizontal extension surface of the formed borehole f ₁ to form a second borehole f _2. Thereafter, as shown in FIG. 10 and FIG. 11 (c), the third earth hole a ₃ is excavated by positioning the middle earth auger b at the unexcavated portion h between the respective earth holes f ₁ and f _2. Then, the drill holes f ₁ , f ₂ , f ₃ are connected in a daisy chain. That is, the vertical holes g ′, g ′ at the adjacent ends of the first and second drill holes f ₁ , f _{2 correspond} to the two earth augers b,
b. In this way, the excavation hole is sequentially formed to form the excavation hole.

[0004] In addition, as shown in Fig. 12, the excavated earth and sand in the excavation hole and the consolidation liquid are mixed to form a solidified underground wall d. That is, the underground wall d is configured such that a part of the adjacent pillars m, m overlap with each other and a plurality of pillars m are arranged continuously in a line in a plan view. Has an H-shaped steel k as a reinforcing material inserted before the excavated earth and sand solidifies.

Japanese Patent Application Laid-Open No. Hei 7-34451 discloses that FIG.
As shown in FIG. 1, an underground wall d provided with reinforcing pillars n at every predetermined pitch is disclosed. That is, this underground wall d is
Adjacent pillars m, part of m overlap each other and pillar m
Are continuously arranged in a row in a plan view, and on one side of the pillar wall p and every other one of the plurality of pillars in a plan view. The reinforcing column portions n are formed so as to partially overlap each other, and inside the wide portion q formed by the reinforcing column portions n and the columns m corresponding to the reinforcing column portions n, An H-shaped steel k having a width larger than the diameter of the column m is provided.

When the underground wall d is formed, a multi-axis excavator (not shown) in which four earth augers are arranged in a substantially T-shape is used for the excavation method described with reference to FIGS. It is formed while excavating the ground.

[0007]

However, in the conventional excavation method, as described with reference to FIGS. 10 and 11, three excavation holes f ₁ and f ₂ are formed between the _first and second excavation holes f ₁ and f _2.
When forming the second excavation hole f ₃ , the _two vertical augers b, b on both sides of the three excavation holes f ₁ , f _{2 at} the adjacent ends of the first and second excavation holes f ₁ , f _2. , G 'portion is dug up, so that a large amount of excavated earth and sand (remaining soil) is discharged and wasted.

In the structure of the underground wall d described with reference to FIG. 12, when the stress applied to the underground wall d is large, the diameter D of each column m is increased to cope with this stress. It is difficult to increase the width of each H-shaped steel k provided inside each column m to increase the strength of the underground wall d. That is, in order to form the column m having a large diameter D, the earth auger b (bit e) of the multi-axis excavator shown in FIG.
, Shafts, screw parts, etc.), but the crane, etc., also needs to be large in size to hold the three earth augers b, which have increased in size and increased in weight. Manufacture of excavator and on-site operation (handling)
Is difficult or impossible.

Further, in the structure of the underground wall d described with reference to FIG. 13, the pitch L of the wide portions q arranged side by side cannot be reduced, and it is possible to cope with a large stress applied to the underground wall d. However, there is a disadvantage that there is little design freedom. In addition, two joints r at portions where the pillars m and m overlap each other are formed between adjacent reinforcing pillars n and n,
Further, since the joints r, r near the reinforcing pillars n, n are located at positions where shear stress is strongly applied, the underground wall has a disadvantageous structure in terms of strength.

Accordingly, an object of the present invention is to provide an underground wall structure and an excavation method which increase the degree of freedom of design and can easily set the strength corresponding to the stress.

[0011]

In order to achieve the above-mentioned object, the structure of the underground wall according to the present invention is arranged such that adjacent pillars partially overlap each other and that the plurality of pillars are provided. A column wall portion which is continuously arranged in a line in a plan view; and the column wall has an axis at a position passing through a joint portion of a column member which is orthogonal to the column wall portion and which is adjacent to the column wall portion in a plan view. Part and a reinforcing column part formed so as to partially overlap each other, and the reinforcing column part is provided only on one side of the column wall part, and every other part of the joint part of the plurality of column bodies is provided. It is provided for each. In addition, the diameter of the reinforcing column is different from the diameter of the column.

Further, according to the excavation method of the present invention, the width dimension larger than the diameter of the column is provided inside the wide portion formed by the reinforcing column and a part of the column wall corresponding to the reinforcing column. H-shaped steel is provided.

[0013] Also, a multiplicity comprising a pair of left and right first earth augers and a second earth auger having an axis at the vertex position of an isosceles triangle in plan view with respect to the axis of the pair of first earth augers. An excavation method for forming an excavation hole in the ground with a shaft excavator, wherein the pair of first earth augers form left and right first excavation holes that partially overlap with each other, and the second earth auger. The auger forms a second borehole partly overlapping the pair of first boreholes to form a single stacked three-bale cross-sectional borehole comprising the first and second boreholes. ,afterwards,
The first and second holes are arranged such that a pair of adjacent first holes is disposed on a horizontal extension surface of the formed pair of first holes.
In the earth auger, an excavation hole with an adjacent three-baled cross section is formed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing embodiments.

FIG. 1 shows an embodiment (first embodiment) of an underground wall structure according to the present invention. The underground wall structure includes a column wall 2 and a column wall 2. And reinforcing pillars 3 provided only on one side.

More specifically, the column wall portion 2 is formed such that a part of the adjacent columnar columns 1 overlaps each other, and a plurality of columnar columns 1... They are arranged side by side in a row. At this time, the mutual interval between the axes 1a, 1a of the adjacent pillars 1, ₁ is set to a predetermined pitch L1.

The columnar reinforcing column 3 has an axis 3a at a position orthogonal to the column wall 2 in a plan view and passing through a joint P between the adjacent columns 1,1. And it is formed so that a part may overlap with the column wall part 2. The reinforcing pillars 3 are provided every other joint P on one side of the plurality of pillars 1. The reinforcing column 3 is disposed at the apex of a regular triangle in plan view with respect to the axis 1a of the column 1, 1 whose axis 3a is adjacent to the column 1, and has a diameter D _{1 of the} column _1. When formed in a substantially same diameter D _2.

Further, a reinforcing bar portion 3, with a portion of Hashirakabe portion 2 corresponding to the reinforcing bar portion 3, the wide portion 4 of the larger width dimension T ₁ than the diameter D ₁ of the columnar member 1 is formed, the inside of the wide portion 4, H-section steel 5 large width T ₂ than the diameter D ₁ of the cylindrical body 1 (core) is provided.

As described above, the structure of the underground wall of the present invention is such that the adjoining pillars are provided at intermediate positions between the adjoining reinforcing walls 3 provided only on one side of the pillar wall 2. Since there is only one joint portion P at 1, 1, a structure having sufficient strength against shear stress applied to one surface of the column wall portion 2 is provided.

FIG. 2 shows a second embodiment of the underground wall structure according to the present invention.
Shows the embodiment, this thing, phase axis 1a phases adjacent posts 1, 1 between adjacent wide portions 4, 4, (than the pitch L ₁₎ a pitch L ₂ between 1a The column wall 2 is formed by setting it to be small. That is, the pitch L3 between the adjacent reinforcing pillars 3, ₃ is set to be small, and the structure has a greater strength against the stress applied to one side of the pillar wall 2.

FIG. 3 shows a third embodiment in which the underground wall structure is such that the diameter D ₂ of the reinforcing column 3 is different from the diameter D ₁ of the column 1 of the column wall 2. It is. That is, the diameter D ₂ of the reinforcing pillar 3 is set to be larger than the diameter D ₁ of the pillar 1 of the pillar wall 2. Thereby, the width dimension T of the wide portion 4
₁ is increased, whereby the inside of the wide portion 4 may be provided with a H-type steel 5 large width dimension T _2, it is possible to increase the strength against stress applied to one side of the Hashirakabe portion 2. In the illustrated example, the column walls 2 are formed with the pitches of the respective columns 1... Being equal intervals. However, as described with reference to FIG. 2 can also be applied.

Further, as shown in the fourth embodiment of FIG. 4, the diameter D ₂ of the reinforcing column 3 can be made smaller than the diameter D ₁ of the column 1 of the column wall 2. That is, the width dimension T ₁ of the wide section 4 can be reduced, and the H-section steel 5 having the small width dimension T ₂ can be provided inside the wide section 4. In the illustrated example, the axis 3a of the reinforcing column 3 is the axis 1a of the adjacent column 1, 1.
The vertex position of an isosceles triangle is set for 1a.

The structure of the underground wall of the present invention is not limited to the above-described embodiment. For example, the H-section steel 5 may be provided only in a desired wide portion 4 among a plurality. Further, an H-section steel having a small width is disposed in the joint P of the adjacent pillars 1, 1 between the wide portions 4, 4, so as to further increase the strength of the joint P against shear stress. Is also good.

Next, the excavation method of the present invention will be described. 5 to 7 show a multi-axis excavator 6, and the present invention is, for example, an excavation method for forming an excavation hole C in a ground A using the multi-axis excavator 6.

The multi-axis excavator 6 has a pair of left and right first earth augers 7, 7 and an axis at a vertex position of an isosceles triangle in plan view with respect to the axis of the pair of first earth augers 7, 7. A second earth auger 8. In the illustrated example, a case is shown in which the second earth auger 8 is disposed at the apex position of the equilateral triangle in plan view with respect to the pair of first earth augers 7 and 7. Reference numeral 9 denotes a bit provided on the shaft 10 of each of the first and second earth augers 7, 7, 8, and each shaft 10 is provided with a stirring bar such as a horizontal rod or a screw for stirring excavated earth and sand. Means 11 are provided.

In the excavation method of the present invention, first, as shown in FIG. 5 and FIG. 8A, the left and right first augers 7, 7 partially overlap each other. 1 drill hole 1
2 and 12, and a second earth auger 8 forms a second drilling hole 13 which partially overlaps the pair of first drilling holes 12, 12 to form first and second drilling holes 12, 12. , 13 to form a single stacked three-bale cross-section borehole C (C ₁ ).

At this time, the first and second earth augers 7,
A consolidation liquid (containing cement or the like) is ejected from a predetermined portion of each of the bits 9 and / or each of the shaft portions 10 of 7 and 8. ) Stirring means 11
Are mixed by stirring.

Thereafter, as shown in FIG. 8 (b), a pair of adjacent first excavation holes 12, 12 are arranged on the horizontally extending surfaces of the formed pair of first excavation holes 12, 12. Then, the first and second earth augers 7, 7, 8 are formed with the excavation holes C having the adjacent three bales-shaped cross section. That is, the first drilling hole C (C
As part the first borehole 12 one of the left and right of the ₁₎ overlap to form two second lap three bale-type cross-section of the borehole C (C _2).

At this time, in plan view, the first drilling holes 12, 12 adjacent to the first and second drilling holes C ₁ , C ₂ are:
Since the area of the overlapping portion M overlapping each other is small, excavated earth and sand (remaining soil) discharged at the time of excavation is significantly reduced.

Next, as shown in FIG. 8C, the first drilling hole C (C ₂ ) partially overlaps the first drilling hole 12 so as to overlap with the first drilling hole 12.
A third drilling hole C (C ₃ ) is formed, and this is repeated to form a continuous drilling hole in the horizontal longitudinal direction. In addition,
The H-shaped steel is inserted before the excavated earth and sand inside the excavation hole solidifies, and the excavated earth and sand is solidified to form the underground wall (described with reference to FIGS. 1 to 4).

The excavation method according to the present invention, as shown in FIG.
(C ₁ ) is formed, and the formed pair of first drilling holes 12 and 12 are formed.
A pair of adjacent first excavation holes on the horizontal extension surface of the
A second excavation hole C (C ₂ ) having a three-layered bale-shaped cross section is formed so that the holes 12 and 12 are arranged at a predetermined interval, and thereafter, the first and second excavation holes C ₁ and C ₂ are formed. During C ₂ (Soil A
In some cases, an excavation hole C (C ₃ ) having a _third stacked three-bale type cross section may be formed in the undigged portion 14).

That is, the first drilling hole of the _third drilling hole C ₃
The first and second excavation holes C in which part of 12, 12 are formed
_1, formed so as to overlap the first borehole 12 and 12 of the C _2, and the borehole C _1, C _2, C ₃ continuous form, then,
The fourth excavation hole is formed apart from the _second excavation hole C2 formed earlier, and excavation is performed in such a manner that the fifth excavation hole is continuous.

The excavation method described with reference to FIGS.
In the adjacent three-bale type cross-section drilling holes, the mutual spacing between the axes 12a, 12a of the overlapping first drilling holes 12, 12 can be freely set to a desired interval. That is, the strength of the underground wall formed thereafter can be easily set. For example, by setting the above-mentioned mutual interval small, the adjacent second excavation holes 13 and 13 approach each other, and as described with reference to FIG. , the pitch L ₃ of the reinforcing bar portion 3 of the formed diaphragm wall becomes the strength increases less.

Further, by changing only the second earth auger 8 (particularly the bit 9) to one having a different diameter, as described with reference to FIGS. 3 and 4, the reinforcing pillar 3 of the underground wall formed is formed. it is possible to easily change the diameter D _2. That is,
The strength setting corresponding to the stress can be easily performed.

Further, as shown in FIG. 6, by excavating the second earth auger 8 so as to be shorter than the pair of first earth augers 7, 7, each second excavation hole 13 is formed in each first excavation hole.
12 can be formed to be shallower, and each of the reinforcing pillars 3 of the underground wall described with reference to FIGS. 1 to 4 can be formed shorter than the pillar wall 2.

As described above, according to the underground wall structure and the excavation method of the present invention, the degree of freedom in designing the underground wall is greatly improved, and it is possible to cope with various location conditions.

[0037]

Since the present invention is configured as described above, the following effects can be obtained.

According to the first aspect of the present invention, the pitch L ₃ of the reinforcing column 3 can be freely set, so that the wall thickness ───, ie, from the end of the reinforcing column 3 to the end of the column wall 2 The strength as an underground wall can be freely set while keeping the width dimension ま で up to the portion the same. Further, since the joint P of the pillars 1, 1 between the reinforcing pillars 3, 3 is formed at one location, the structure is advantageous in terms of strength against shear stress.

According to the second aspect, the strength of the underground wall corresponding to the stress can be set. According to the third aspect, the strength of the underground wall can be further increased, and the H-shaped steel 5 having a required size corresponding to the stress can be provided.

According to the fourth aspect of the present invention, the excavated earth and sand (remaining earth) discharged during the excavation operation is greatly reduced. That is,
The area to be excavated twice (excavation) is extremely small and work efficiency is good. In addition, the excavation hole C of three stacked bales type cross section
Or the excavation diameter of the second earth auger 8 (bit 9), ie, the diameter D ₂ of the second excavation hole 13
─── can be changed freely, or the depth of the second drilling hole 13 can be set smaller than that of the first drilling holes 12, 12. That is, the degree of freedom in designing the underground wall can be increased.

[Brief description of the drawings]

FIG. 1 is a sectional plan view showing a first embodiment of a structure of an underground wall according to the present invention.

FIG. 2 is a cross-sectional plan view showing a second embodiment.

FIG. 3 is a cross-sectional plan view showing a third embodiment.

FIG. 4 is a cross-sectional plan view showing a fourth embodiment.

FIG. 5 is a front view showing an earth auger of the multi-axis excavator.

FIG. 6 is a side view showing a tip portion of the earth auger.

FIG. 7 is a cross-sectional plan view showing an arrangement of an earth auger.

FIG. 8 is an explanatory diagram showing an excavation step.

FIG. 9 is an explanatory view showing another excavation step.

FIG. 10 is an explanatory diagram showing a state of formation of a conventional excavation hole.

FIG. 11 is an explanatory diagram illustrating an excavation step.

FIG. 12 is a cross-sectional plan view showing a structure of a conventional underground wall.

FIG. 13 is a cross-sectional plan view showing another structure of the underground wall.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Column 2 Column wall 3 Reinforcement column 3a Axis 4 Wide part 5 H-section steel 6 Multi-axis excavator 7 First earth auger 8 Second earth auger 12 First drill hole 13 Second drill hole A Ground C drill hole D ₁ diameter D ₂ diameter P junction T ₂ width

Claims (4)

[Claims] 1. A column wall portion 2 in which a plurality of column members 1 are arranged in a row in a plan view so that a part of adjacent column members 1 overlap with each other, and The column wall 2 in plan view
And a reinforcing column portion 3 having an axis 3a at a position passing through the joint portion P of the adjacent columnar bodies 1 and 1 and being formed so as to partially overlap the column wall portion 2. The reinforcing column 3 is provided only on one side of the column wall 2 and a plurality of columns 1
The underground wall structure is arranged every other joining portion P of... 2. The underground wall structure according to claim 1, wherein the diameter D ₂ of the reinforcing pillar 3 is different from the diameter D ₁ of the pillar 1. 3. A column 1 inside a wide portion 4 formed by a reinforcing column 3 and a part of a column wall 2 corresponding to the reinforcing column 3.
Structure of the underground wall of claim 1 or 2 wherein the H-section steel 5 large width dimension T ₂ is provided than the diameter D _1. 4. A pair of left and right first earth augers 7, 7,
Excavation on the ground A by a multi-axial excavator 6 including a pair of first earth augers 7, 7 and a second earth auger 8 having an axis at a vertex position of an isosceles triangle in plan view. An excavation method for forming a hole C, wherein the pair of first earth augers 7, 7 partially overlap each other with first and second first earth augers 7, 7.
In addition to forming the second and the second drilling holes, the second earth auger 8 partially overlaps the pair of the first drilling holes 12 and 12.
13 comprising a first and a second borehole 12, 12, 13
A drill hole C having a cross section of three stacked bales is formed.
The first and second earth augers 7, 7, 8 are arranged so that a pair of adjacent first dig holes 12, 12 is disposed on a horizontal extension surface of the formed pair of first dig holes 12, 12. The excavation method according to claim 1, wherein an excavation hole C having an adjacent three bales-shaped cross section is formed in the step (a).