JP7261119B2 - Earth retaining structure - Google Patents

Description

The present invention relates to an earth retaining structure that separates the ground from the excavation side, particularly when the groundwater level is lower than the planned excavation depth (i.e., when the groundwater level outside the earth retaining is lower than the ground with floor inside). ), it relates to an earth retaining structure based on the parent pile + horizontal sheet pile construction method.

Various types of buildings, vertical shafts, underground tanks, and the like are examples of underground structures constructed in the ground by vertically digging the ground. In the case of vertical excavation, before excavating the interior, a retaining wall made of a continuous wall made of soil mortar is constructed by the SMW construction method, the TRD construction method, or the like.

If the groundwater level in the surrounding area is lower than the floor ground inside the earth retaining, the groundwater will not enter, so the main pile + horizontal sheet pile construction method can be applied as the earth retaining.

In the parent pile + horizontal sheet pile construction method, H-shaped steel (for example, H-300 x 300) is erected at intervals of 1 to 2m as a parent pile, and the inside is excavated in a range where the soil behind can stand on its own. Between the webs, the horizontal sheet pile is inserted in such a way that both ends are locked to the back of the excavation side flange of the H-shaped steel. As the horizontal sheet piles, wooden thick plates, square timbers, sheet piles (steel sheet piles), H-shaped steel (for example, H-150×150), etc. are used.

Patent Literature 1 discloses a master pile + horizontal sheet pile construction method. However, this is an example of when the groundwater level outside the earth retaining is higher than the ground with floor inside, and a permeable sheet is placed on the back side of the horizontal sheet and a waterproof sheet is placed on the surface side to treat subsoil water. ing.

Japanese Patent No. 4532337

However, the conventional master pile + horizontal sheet pile construction method has the following problems.
A large number of horizontal sheet piles are required, and after use they are either left as they are or they are removed and discarded. Even when the horizontal sheet pile is H-shaped steel, it is cut short to 1 to 2 m, so it becomes industrial waste.

Manually excavating around the web of the main pile (H-shaped steel) (back side of the flange on the excavation side) and inserting the horizontal sheet pile takes time and effort.
The horizontal sheet pile weighs 30 to 60 kg (when the distance between the main piles is 1 to 2 m), and it is difficult to install by human power alone.

The horizontal sheet piles are placed from the top and the bottom is excavated, so there is a possibility that they will fall.
In addition, since the required excavation depth (exposed surface) is increased due to manual excavation under the installed horizontal sheet piles, and the horizontal sheet piles are inserted diagonally into the back of the flange, there is also the possibility of collapse due to this. There is
In addition, usually, a wedge is driven between the flange and the horizontal sheet pile to prevent the horizontal sheet pile from falling, but this causes an increase in man-hours.

Patent document 1 is a parent pile + horizontal sheet pile construction method in excavation below the groundwater level. Therefore, since groundwater infiltrates, a water-permeable sheet is placed on the back side of the horizontal sheet pile, and a water-blocking sheet is placed on the surface side, and the infiltrated water is collected in an internal pit and drained.
However, in the main pile + side sheet pile construction method, the side sheet pile is inserted after excavating the front surface, and if such excavation is performed in an area with groundwater, there is a risk of ground collapse.

In view of such circumstances, it is an object of the present invention to provide an earth retaining structure that is suitable when the groundwater level is lower than the planned excavation depth.

The earth retaining structure according to the present invention comprises: a plurality of parent piles arranged at predetermined intervals so as to separate the ground from the excavation side; a cloth material stretched in a plane between the adjacent parent piles; and a cloth material fixture for fixing the cloth material to the excavation side surface of the parent pile.

The cloth material has a thick portion formed to be thicker than the other portion in a part of the cloth material, and the cloth material fixture is fixed to the main pile, and the cloth material has the thickness of the cloth material. It engages with the part in the stretching direction.

The cloth material fixture includes a half pipe extending in a direction perpendicular to the stretching direction of the cloth material and pressed by a cylindrical surface against a non-thickness portion near the thickness portion, and both ends of the half pipe. to the parent pile.

As described above, the present invention relates to an earth retaining structure that separates the ground from the excavation side. , fabric material (also referred to herein as "cloth sheet pile") is used in place of the usual wooden or steel cross sheet piles.

According to the present invention, the horizontal sheet piles are made of fabric material that is much lighter than the conventional wooden or steel ones, so that manual installation is easy and workability is excellent.
Also, the cloth material can be attached to the surface of the excavation side of the parent pile, which also facilitates the attachment.
Moreover, the cloth material can be left as it is, or when it is removed or disposed of, the amount is extremely small, and the disposal cost is low.

As described above, the construction method of the present invention is very efficient and can reduce costs under the condition that there is no groundwater behind the earth retaining.

Diagram showing construction example using earth retaining Front view of the retaining wall seen from the direction of arrow II in Fig. 1 Plan view of the retaining wall in Fig. 2 Right side view of the retaining wall in Fig. 2 A plan view and a front view showing a cloth processed shape as an example of a first fixing structure of the cloth material. Member diagram and installation diagram in the first fixed structure example A plan view and a front view showing a cloth processing shape as an example of a second fixing structure of the cloth material. Member diagram and installation diagram in the second fixed structure example

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a diagram showing an example of construction using earth retaining.

When constructing underground structures (various buildings, shafts, underground tanks, etc.) under the construction ground 1, prior to this, the ground side (non-excavation area) and the excavation side (planned excavation area) are separated. , earth retaining (earth retaining) 2 is constructed.

In particular, the earth retaining 2 of this example is an earth retaining by the parent pile + horizontal sheet pile construction method, which is suitable for such a case, on the premise that the groundwater level GWL of the construction ground 1 is lower than the planned excavation depth (ground with floor 7). , H-shaped steel is used as the main pile, and cloth material (cloth sheet pile) is used as the horizontal sheet pile. However, in FIG. 1, only the parent pile 3 made of H-shaped steel is shown, and the illustration of the cloth material 4 is omitted.

A plurality of parent piles 3 are arranged at predetermined intervals (for example, intervals of 1 to 2 m) along a virtual partition line between the ground side (non-excavation area) and the excavation side (planned excavation area) of the construction ground 1. is erected vertically into the ground. The built-in depth is set deeper than the scheduled excavation depth (floor ground 7).

The parent pile 3 is basically made of H-section steel (for example, H-300×300). Therefore, the main pile 3 has a pair of front and rear flanges and a web connecting the central portions of both flanges.

The main pile 3 made of H-section steel is installed such that a pair of front and rear flanges thereof are opposed to each other in the width direction of the earth retainer 2 . Therefore, the webs of the main piles 3 adjacent to each other in the extending direction of the earth retaining 2 (the rowing direction of the main piles 3) are opposed to each other.

After erecting the main pile 3, the inner side of the row of the main pile 3 (excavation side partitioned by the row of the main pile 3) is excavated. Then, as the excavation progresses, in other words, every time a predetermined depth (for example, 20 to 30 cm) is excavated, a cloth material 4 (Fig. 2) equivalent to a horizontal sheet pile is placed between the exposed portions of the adjacent parent piles 3. pass over A method for installing the cloth material 4 here will be described in detail later.

Then, excavation and installation of cloth materials (cloth sheet piles) equivalent to horizontal sheet piles are repeated, and wales 5 and struts 6 are installed at predetermined depths. Excavate to the ground 7) (state of Fig. 1).

After that, an underground structure (not shown) is constructed on the floor ground 7, and the gap between the earth retaining structure and the earth retaining structure is backfilled to complete the construction.

Next, the cloth material 4 stretched between the adjacent parent piles 3, 3 will be described.
2 is a front view of the earth retainer viewed from the direction of arrow II in FIG. 1, FIG. 3 is a plan view of the earth retainer of FIG. 2, and FIG. 4 is a right side view of the earth retainer of FIG.

The cloth material 4 stretched between the main piles 3, 3 adjacent to each other at intervals of 1 to 2 m has a predetermined tensile strength, and is made of, for example, a civil engineering sheet, canvas, carbon fiber cloth, etc., and has a width of 20 to 30 cm. It is formed like a strip. In addition, since civil engineering sheets are thin, a plurality of sheets may be overlapped and used.
A cloth material fixture 20 for fixing the cloth material 4 to the excavation side flange surface of the main pile 3 is provided.

The cloth material fixing structure by the cloth material fixing tool 20 will be described with reference to FIGS. 5 and 6. FIG.
FIG. 5 is a plan view (A) and a front view (B) showing a cloth processing shape as an example of a first fixing structure for the cloth material. FIG. 6 is a diagram (A) of members and diagrams (B) and (C) of installation in the first fixing structure example.

The cloth material fixing structure in this example includes thick portions 10 formed by making both ends of the cloth material 4 (portions corresponding to the main piles 3) thicker than the other portions, and a cloth material fixed to the main piles 3. and a cloth material fixture 20 that engages the thick portion 10 of the material 4 in the stretching direction.

The thick portions 10 at both ends of the cloth material 4 are formed as follows.
The cloth material 4 is double-folded at both ends (folded portion 11), and sewn together with a rope-like member 12 having a diameter of 15 to 20 mm held therein (stitched portion 13). . As a result, a thick portion 10 having a thickness greater than that of the other portions is formed by the folded portion 11 and the rope-like member 12 at both ends of the cloth material 4 (at positions corresponding to the main piles 3).
The rope-shaped member 12 may be a rod-shaped member having a certain thickness, such as a rope.

The cloth material fixture 20 includes a half pipe 21 that is applied to the non-thickness portion of the cloth material 4 near the thickness portion 10 on the excavation side flange surface of the main pile 3, and both ends of the half pipe 21 are attached to the main pile. 3 and bolts 22 that are fixed to it.

The half pipe 21 is made by dividing a metal pipe in half, and extends in a direction (vertical direction) perpendicular to the stretching direction of the cloth material 4, and its cylindrical surface is the excavation side flange of the main pile 3. It is pressed against the cloth material 4 on the surface, particularly the non-thickness portion near the thickness portion 10 of the cloth material 4 (the non-thickness portion inside the thickness portion 10 in the stretching direction). Damage to the cloth material 4 can be prevented by contacting the cloth material 4 with the cylindrical surface.

The half tube 21 is longer than the width of the cloth material 4 and has bolt insertion holes 21a at both ends (portions protruding from the upper and lower edges of the cloth material 4).
Threaded holes 23 are formed in the excavation side flange of the main pile 3 so as to correspond to the bolt insertion holes 21 a at both ends of the half pipe 21 . A threaded hole 23 is provided on the excavation side flange of the main pile 3, avoiding the web position.

Therefore, when the width of the cloth material 4 is, for example, 25 cm, the end of the cloth material 4 is placed on the exposed flange surface of the main pile 3 every time the depth of one cloth material 4 is excavated, for example, 30 cm. Then, the cylindrical surface of the half pipe 21 is put on the cloth material 4 (the non-thick part near the thick part 10), and the bolts 22 are inserted through the bolt insertion holes 21a at both ends of the half pipe 21, It screws into the threaded hole 23 of the flange. By adopting such a fixing method, the cloth material 4 is not provided with notches or through holes that cause the cloth material 4 to tear. A rubber plate having a thickness of about 5 mm may be interposed between the cloth material 4 and the half tube 21 .

As a result, the cloth material 4 is stretched between the main piles 3 and 3 by the cloth material fixtures 20 (half pipes 21) locking the thick portion 10 in the stretching direction at both ends thereof. be More specifically, when earth pressure acts on the cloth material 4 and tensile force acts on it, the thick part 10 bites into the cloth material fixture 20 (half pipe 21 ) and becomes the fixed end of the cloth material 4 . Thereby, the cloth material 4 functions as an earth pressure resistance member.

Moreover, on the flange of one parent pile 3, as shown in FIG. are superimposed on each other and fixed with a common fabric fixture 20 (half pipe 21 and bolt 22).

In this example, the screw hole 23 is formed in the flange of the main pile 3, but instead of the screw hole 23, a bolt insertion hole may be formed and fixed using a nut.
In the case of the threaded hole 23, the threaded hole 23 can be protected by screwing the bolt 22 in advance when the main pile 3 is erected.

In order to prevent interference between the cloth fixing members 20 of the cloth members 4 adjacent to each other in the vertical direction, the fixing positions of the cloth fixing members 20 are staggered in the horizontal direction as shown in FIG. changing to become This is to minimize the gap between the cloth members 4,4.
In this case, the gap between the cloth members 4 may be made smaller by making the width of the cloth member 4 wider at the intermediate portion than at both ends.

Another fabric fixing structure will be described with reference to FIGS. 7 and 8. FIG.
FIG. 7 is a plan view (A) and a front view (B) showing a cloth processing shape as a second fixing structure example of the cloth material. FIG. 8 is a member diagram (A) and installation diagrams (B) and (C) in the second fixing structure example.

In this fixing structure example, the cloth material 4 is stretched over the main pile 3 in a connected state without being divided.
For this reason, the intermediate portion of the cloth material 4 is folded over the flange of the main pile 3 so as to form three folds, and the rope-like members 12, 12 are held in the left and right folded portions 11, 11, respectively, and sewn. are sewn together (stitched portions 13, 13).
Accordingly, in this case, thick portions 10, 10 are formed by the rope-like members 12, 12 on the right and left sides of the sewn portion 13 in the intermediate portion of the cloth material 4. As shown in FIG.

Therefore, on the flange of each main pile 3, the center (non-thick part) between the thick parts 10, 10 formed by the pair of left and right rope-shaped members 12, 12 is pressed by the cloth material fixture 20 (half pipe 21), By fixing the upper and lower ends with bolts 22, the cloth material 4 can be stretched between the adjacent main piles 3, 3. - 特許庁

As described above, the following effects can be obtained by using cloth materials (cloth sheet piles) in place of conventional wooden or steel horizontal sheet piles.
Since the cloth material 4 including the rope-like member, which is much lighter than the conventional one, is used, it is easy to attach manually and is excellent in workability.

Moreover, the cloth material 4 can be attached to the outer surface of the excavation side flange of the main pile 3, and the attachment is extremely easy without the need to excavate the inside of the flange.
Moreover, the cloth material 4 may be left as it is, or when it is removed or disposed of, the amount is extremely small, and the disposal cost is low.

The method of constructing an earth retaining using cloth sheet piles as described above can be realized by the following steps (1) to (3) on the condition that the groundwater level is lower than the planned excavation depth.
(1) Parent pile insertion step; A plurality of parent piles are inserted into the ground at predetermined intervals so as to separate the ground from the excavation side.
(2) Excavation step; Excavating the excavation side of the parent pile (by a predetermined depth).
(3) Cloth material fixing step; As the excavation progresses (each time the excavation is performed by the predetermined depth), the cloth material is stretched between the exposed portions of the adjacent main piles to fix the excavation side surface of the main piles. to secure the cloth material to.

The above earth retaining construction method is very efficient and can reduce costs, provided that the groundwater level is lower than the planned excavation depth and there is no groundwater behind the earth retaining.

It should be noted that the illustrated embodiment is only a schematic illustration of the present invention, and that the present invention, in addition to what is directly indicated by the described embodiment, can also be made by those skilled in the art within the scope of the claims. Needless to say, it includes the improvement and change of
The claims as originally filed were as follows.
[Claim 1]
An earth retaining structure that separates the natural ground side and the excavated side of the ground,
a plurality of parent piles arranged at predetermined intervals so as to separate the ground from the excavation side;
A cloth material stretched in a plane between adjacent parent piles,
a cloth material fixture for fixing the cloth material to the excavation side surface of the parent pile;
An earth retaining structure, characterized by comprising:
[Claim 2]
The cloth material has a thick portion formed to be thicker than the other portion in a part of the stretching direction,
2. The earth retaining structure according to claim 1, wherein said cloth material fixing member is fixed to said main pile and engages said thick portion of said cloth material in a stretching direction.
[Claim 3]
3. The earth retaining structure according to claim 2, wherein said thick portion is formed by folding back and stitching the ends of said cloth material in two and arranging a rope-like member therein.
[Claim 4]
The thick part is formed by folding back the intermediate part of the cloth material three times and sewing them together, and arranging two rope-like members therebetween with an interval therebetween. 2. The earth retaining structure according to 2 above.
[Claim 5]
The cloth material fixture includes a half pipe extending in a direction perpendicular to the stretching direction of the cloth material and pressed by a cylindrical surface against a non-thickness portion near the thickness portion, and both ends of the half pipe. The earth retaining structure according to any one of claims 2 to 4, further comprising a bolt for fixing to the main pile.
[Claim 6]
A method for constructing an earth retaining for partitioning the ground from the ground side to the excavation side when the groundwater level is lower than the planned excavation depth,
a parent pile inserting step of inserting a plurality of parent piles into the ground at predetermined intervals so as to separate the ground from the excavation side;
an excavation step of excavating the excavation side of the parent pile;
a cloth material fixing step of stretching a cloth material between the exposed portions of adjacent parent piles and fixing the cloth material to the surface of the parent pile on the excavation side as the excavation progresses;
A method for constructing an earth retaining, comprising:

1 Construction ground 2 Earth retaining 3 Main pile (H-shaped steel)
4 Cloth materials (cloth sheet piles)
5 wale 6 strut 10 thickness part 11 folded part 12 rope-like member 13 sewn part 20 cloth material fixture 21 half pipe 21a bolt insertion hole 22 bolt 23 screw hole

Claims (3)

An earth retaining structure that separates the natural ground side and the excavated side of the ground,
a plurality of parent piles arranged at predetermined intervals so as to separate the ground from the excavation side;
A cloth material stretched in a plane between adjacent parent piles,
a cloth material fixture for fixing the cloth material to the excavation side surface of the parent pile;
with
The cloth material has a thick portion formed to be thicker than the other portion in a part of the stretching direction,
The cloth material fixture is fixed to the main pile and engages with the thick portion of the cloth material in the stretching direction,
The cloth material fixture includes a half pipe extending in a direction perpendicular to the stretching direction of the cloth material and pressed by a cylindrical surface against a non-thickness portion near the thickness portion, and both ends of the half pipe. and bolts for fixing to the parent pile . 2. The earth retaining structure according to claim 1 , wherein said thick portion is formed by folding back and stitching the ends of said cloth material in two and arranging a rope-like member therein. 2. The mountain according to claim 1 , wherein said thick portion is formed by folding a middle portion of said cloth material three times and stitching them together, and arranging two rope-like members therein with a space therebetween. retention structure.

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