JP2015221993A - Earth retaining wall and construction method for the earth retaining wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an earth retaining wall that cuts off water at prescribed locations and may be constructed simply at reduced costs.SOLUTION: An earth retaining wall 1 includes H-shaped steel 11, soil cement 13, a steel plate 15 and others, and is constructed on a permeable layer 101 and an impermeable layer 102 of the ground 100. The soil cement 13 is filled in a water cutoff section in a part in the height direction of the H-shaped steel 11, to be in contact with the adjacent pieces of H-shaped steel 11. The soil cement 13 is filled by high-pressure injection of cement milk from a rod 20 inserted directly into the ground 100 between the adjacent pieces of H-shaped steel 11, and then mixed and agitated with the soil in the ground 100.

Description

  The present invention relates to a retaining wall and a construction method thereof.

  When constructing an underground structure, a mountain retaining wall is constructed, and then an excavation site ahead is excavated. When excavating the ground deeper than the groundwater level, a soil cement wall having a water stopping function is used as a retaining wall.

  The soil cement wall is composed of a plurality of columnar bodies of soil cement, and a continuous wall having a water stopping function is constructed by wrapping adjacent columnar bodies together. The soil cement columnar body is excavated with a drilling blade such as an auger head to form a drilling hole with a diameter corresponding to the columnar body, and the ground soil and cement milk etc. are mixed and stirred in the drilling hole with a screw etc. Then, it is constructed by inserting a core material such as H-shaped steel into the excavation hole.

  Patent Documents 1 and 2 describe that when a soil cement wall is constructed, the columnar body of the soil cement is wrapped only at a portion where water stop is necessary, thereby reducing the material cost.

  As an example of another mountain retaining wall, Patent Document 3 describes that a water retaining portion is provided at a position where the flow of groundwater in the ground is blocked behind the mountain retaining wall composed of a main pile and a lateral sheet pile.

JP 2012-107444 A Japanese Patent Laid-Open No. 9-279568 JP 2009-68203 A

  In each of Patent Documents 1 to 3 described above, a water stop function is given only to a necessary portion. However, in a soil cement wall as in Patent Documents 1 and 2, cement milk or the like is spread over the entire length of the core material. Since it is filled, the material cost is still high even by the above-mentioned method, and it is necessary to cast a core material before the cement milk or the like is hardened, so that the construction is difficult. In addition, the method of Patent Document 3 has a problem in terms of cost because it uses a horizontal sheet pile that supports earth pressure and a water stop.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a mountain retaining wall or the like that can be water-stopped at a predetermined location, can be easily constructed, and can be reduced in cost. .

  The first invention for achieving the above-described object is that the plurality of pile members placed on the ground and the water-stopping material are filled only with a part in the height direction of the pile members, so that the adjacent ones It is a mountain retaining wall characterized by comprising the water stop part formed so that a pile material may be contacted.

  It is desirable that the water blocking material is filled from between the adjacent pile materials. Moreover, it is desirable that the water stop material is filled so as not to protrude in front of the pile material. Furthermore, it is desirable to further include a plate material provided between the pile materials adjacent to each other, except for a portion where the water blocking material is filled in the height direction of the pile material.

  As for 2nd invention, it fills with a water stop material only in the process of placing a plurality of pile materials in the ground, and only a part of the height direction of the pile materials so that it contacts the adjacent pile materials. And a step of forming a water stop portion.

  It is desirable to fill the waterstop material from between the adjacent pile materials. Moreover, it is desirable that the water-stopping material is filled by performing high-pressure injection from a rod inserted directly into the ground. Moreover, it is desirable that the water stop material is filled so as not to protrude in front of the pile material. Furthermore, it is desirable to further comprise a step of providing a plate material between the pile materials adjacent to each other, except for a portion where the waterstop material is filled in the height direction of the pile material.

  According to the present invention, since the water stop material is formed by filling only a part of the pile material in the height direction, the amount of the water stop material is reduced as compared with the conventional soil cement wall, Can be easily constructed and the cost of the material can be suppressed, which is also preferable from the environmental viewpoint. In addition, after placing the pile material, it is possible to fill the water-stopping material from between the adjacent pile materials to form the water-stop part, so there is no need to drive the pile material before hardening the water-stopping material. Easy. Furthermore, since the water stop part is formed so as to be in contact with the pile material, the earth pressure can be suitably borne by this, and the lateral sheet piles can be omitted. In addition, if water is discharged from a portion other than the water filling material, such as a layer with a small proportion of sandy or gravel in all layers, a separate plate is provided, and leakage due to water leakage that could not be assumed. Damage can be prevented. Moreover, earth pressure can also be borne by a board | plate material.

  Further, by filling the water-stopping material by high-pressure injection from the rod directly inserted into the ground, the water-stopping material and the soil of the ground are mixed and stirred, and the water-stopping portion can be easily formed by replacing the ground. Further, since it is not necessary to excavate a drilling hole having a diameter corresponding to the water stop portion, the excavating blade does not interfere with the pile material during ground excavation. Furthermore, it is not necessary to remove the water stop portion when excavating the ground by filling the water stop material so that it does not protrude in front of the pile material.

  ADVANTAGE OF THE INVENTION According to this invention, the water retaining wall etc. which can be water-stopped in a predetermined location, and can be constructed | assembled easily and the cost can be suppressed can be provided.

The figure which shows the retaining wall 1 Perspective view of mountain retaining wall 1 The figure which shows the horizontal direction cross section of the retaining wall 1 The figure which shows the construction method of the retaining wall 1 The figure which shows the construction method of the retaining wall 1 Diagram showing filling of cement milk The figure explaining the retaining wall 1a and its construction method

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First embodiment]
(1. Mountain retaining wall 1)
First, a mountain retaining wall according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a view showing a mountain retaining wall 1 as seen along the height direction. FIG. 2 is a perspective view of the retaining wall 1, and FIG. 3 is a view showing a horizontal section of the retaining wall 1. FIG. 3A shows a horizontal section at the position of the soil cement 13, and FIG. 3B shows a horizontal section at the position of the steel plate 15.

  The mountain retaining wall 1 is provided on the ground 100. The ground 100 has a water permeable layer 101 such as sandy soil and a water impermeable layer 102 such as viscous soil. The excavation location 200 is formed by excavating the ground 100 in front of the retaining wall 1. Hereinafter, in the retaining wall 1, the front refers to the direction of the excavation site 200, and the rear refers to the direction of the ground 100.

  The retaining wall 1 includes an H-shaped steel 11, a soil cement 13, a steel plate 15, and the like, and is provided in the water-permeable layer 101 and the water-impermeable layer 102 of the ground 100.

  The H-shaped steel 11 is a pile material provided in the height direction of the retaining wall 1, and a plurality of H-shaped steels 11 are provided at intervals on a plane.

  The soil cement 13 is a part of the H-shaped steel 11 in the height direction, and is a water stop portion provided in a water stop target section such as the water permeable layer 101 where water stop is desired. The soil cement 13 is formed by filling cement milk (water-stopping material) from between the H-shaped steels 11, mixing with the soil of the ground 100 and stirring, and as shown in FIG. It is provided in contact with the web or the like.

  The steel plate 15 is a part other than the soil cement 13 (the place where the cement milk is filled) in the height direction of the H-shaped steel 11, as shown in FIG. It is a plate material that is provided in a portion where there is a fear. The steel plate 15 is an iron plate, for example, and is fixed to the flange of the H-shaped steel 11 by welding or the like so as to cover the front between the adjacent H-shaped steels 11.

  In the present embodiment, the impervious layer 102 is very strong, and it is assumed that earth pressure is not generated on the retaining wall 1 in the impermeable layer 102, and the steel plate 15 is only attached to the water discharge portion or the like. In a place where earth pressure is generated on the retaining wall 1, it is preferable to attach a plate material such as a sheet pile between the H-shaped steels 11 to support the earth pressure.

(2. Construction method of mountain retaining wall 1)
Next, the construction method of the mountain retaining wall 1 will be described. When the mountain retaining wall 1 is constructed, first, the H-shaped steel 11 is inserted into the ground 100 as shown in FIG. The H-shaped steel 11 is inserted by a conventional method such as a vibration method, a pre-boring method, or a forced press-fitting method, and as described above, a plurality of H-shaped steels 11 are provided at intervals on a plane.

  In the present embodiment, the soil cement 13 is formed using a high-pressure jet stirring method that is frequently used for ground improvement. That is, as shown in FIG. 4B, one rod 20 is directly inserted into the ground 100 between the H-shaped steel 11, and from the nozzle (not shown) at the rod end in the water stop target section. Fill with cement milk by high pressure injection.

  While lifting the rod 20, the cement milk is sprayed from the nozzle at the rod end toward the surrounding ground 100 as shown by an arrow as shown in FIG. After mixing and stirring, the soil cement 13 is formed by replacing the ground 100 as shown in FIG.

  In the example of FIG. 6, the rod 20 is inserted at a position corresponding to the vicinity of the center of the web of the H-shaped steel 11, the cement milk protrudes and fills the front of the H-shaped steel 11, and the soil cement 13 is filled with the H-shaped steel 11. Projecting forward. In this example, the cement milk is injected at a high pressure so that the soil cement 13 has a substantially circular cross section. However, when the soil cement 13 is formed, the cement milk may be injected at a high pressure so that the soil cement 13 has a non-circular cross section. Is possible. The width of the soil cement 13 can also be changed according to the interval of the H-shaped steel 11. Furthermore, the cement milk can be sprayed not only in the horizontal direction but also downward from a nozzle (not shown) at the tip of the rod. In this case, the cement milk is sufficiently injected even at the lower end of the water stop target section. It can be filled, and the adhesion between the soil cement 13 and the H-shaped steel 11 is increased, and the water stoppage is improved.

  Returning to the description of the method for constructing the retaining wall 1. Next, as shown in FIG. 5A, the ground 100 in front of the H-shaped steel 11 is excavated. At the position of the soil cement 13, excavation is performed while removing the soil cement 13 protruding forward of the H-shaped steel 11.

  Thereafter, further excavation is continued from the position of the soil cement 13 downward. As shown in FIG.5 (b), the steel plate 15 is provided between the adjacent H-shaped steel 11 as mentioned above in required places, such as a water discharge part. When excavation is performed to the required depth in this way, the retaining wall 1 described in FIG.

  As described above, according to the present embodiment, since the cement cement is formed by filling cement milk only in a part in the height direction of the H-shaped steel 11, the amount of cement milk is larger than that of the conventional soil cement wall. Therefore, the soil cement 13 can be easily constructed and the cost of the material can be suppressed. Moreover, since the soil cement 13 can be formed by first filling the H-shaped steel 11 and then filling cement milk between the adjacent H-shaped steels 11, it is necessary to cast the H-shaped steel 11 before the cement milk is hardened. Easy to install. Furthermore, since the soil cement 13 is formed so as to come into contact with the H-shaped steel 11, the earth pressure can be suitably borne by this, and a side sheet pile or the like can be omitted. However, it is possible to further provide a horizontal sheet pile or the like between the H-shaped steel 11 at the place where the soil cement 13 is provided.

  Further, in the portion other than the soil cement 13, for example, when the water is discharged in a layer having a small proportion of sandy soil or sandy gravel, the steel plate 15 is provided as described above in the water discharge portion, etc. Damage caused by water leakage can be easily prevented. It is also possible to bear earth pressure with a horizontal sheet pile or the like.

  Furthermore, by filling the cement milk with the cement milk by performing high-pressure injection from the rod 20 directly inserted into the ground 100, the cement milk and the soil of the ground 100 are mixed and stirred, and the soil cement 13 can be easily formed by replacing the ground 100. Further, since it is not necessary to excavate a drilling hole having a diameter corresponding to the soil cement 13, the excavating blade does not interfere with the H-shaped steel 11 during ground excavation.

  However, the present invention is not limited to this. For example, the pile material is not limited to the H-shaped steel 11, and angle steel, C-shaped steel, steel pipes, wooden piles, and the like can also be used. Moreover, as a water stop material, the thing by water glass of cement milk, the high pressure injection of a chemical | medical solution, etc. can be considered.

  Moreover, the water stop target section should just be a section which wants to stop water, and is not restricted to the water permeable layer 101. FIG. For example, even in the impermeable layer 102 such as clay soil, since some sand is mixed, if it is desired to stop the water on a plan basis or if it is desired to completely stop the water, this is set as the water stop target section. Or conversely, if water is to be passed through the water permeable layer 101 as well, it is not set as a water-stop target section in the plan.

  In the example of FIG. 1, the lower end portion of the retaining wall 1 reaches the impermeable layer 102, but the relationship between the layer of the ground 100 and the depth of the retaining wall 1 is not limited thereto. For example, the bottom end of the mountain retaining wall 1 may be in the water permeable layer 101. Further, due to the groundwater level being at a lower position, even the section of the permeable layer 101 or the like that does not have groundwater at all times may be set as a water-stop target section from the viewpoint of measures in case of precipitation. Furthermore, the number of water stop target sections is not limited to one, and a plurality of sections may be set apart in the height direction. In this case, the water stop part such as the soil cement 13 may be formed in each of the plurality of water stop target sections to perform the water stop.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. 2nd Embodiment is an example from which the formation position of the soil cement 13 differs, and since it is the same about others, description is abbreviate | omitted.

  Fig.7 (a) is a figure which shows the horizontal direction cross section in the position of the soil cement 13 of the retaining wall 1a. As shown in FIG. 7A, in this embodiment, the cement milk is filled so as not to protrude forward of the H-shaped steel 11, and the soil cement 13 is formed so as not to protrude forward of the H-shaped steel 11.

  When constructing the retaining wall 1a, as shown in FIG. 7B, the position where the rod 20 is inserted into the ground 100 is shifted rearward from the vicinity of the center of the web of the H-shaped steel 11, and the arrow from the nozzle at the rod end Cement milk is injected at a high pressure as shown in FIG. Thereby, the cement milk can be filled so as not to protrude to the front of the H-shaped steel 11.

  In this case, when excavating the ground 100, it is not necessary to remove the soil cement 13 as described above with reference to FIG. Therefore, excavation work becomes easy, the disposal cost of the soil cement 13 can be reduced, and this is preferable from the environmental viewpoint.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs.

1, 1a ......... Mountain retaining wall 11 ... ... H-shaped steel 13 ... ... Soil cement 15 ... ... Steel plate 100 ... ... Ground 200 ... ... Excavation point

Claims (9)

A plurality of piles placed on the ground,
By filling the water-stopping material only with a part in the height direction of the pile material, the water-stop portion formed so as to contact the adjacent pile material,
A retaining wall characterized by comprising:   The mountain retaining wall according to claim 1, wherein the water blocking material is filled from between the adjacent pile materials.   The mountain retaining wall according to claim 1 or 2, wherein the water blocking material is filled so as not to protrude in front of the pile material.   The plate material provided between the said adjacent pile materials is further comprised in a part except the filling location of the said water stop material of the height direction of the said pile material, The Claim 1- Claim 3 characterized by the above-mentioned. The retaining wall according to any one of the above. A process of placing a plurality of pile materials on the ground;
The step of forming the water stop portion so as to contact the adjacent pile material by filling the water stop material with only a part of the height direction of the pile material,
A method for constructing a retaining wall, characterized by comprising:   6. The method for constructing a retaining wall according to claim 5, wherein the water blocking material is filled from between the adjacent pile materials.   The method for constructing a retaining wall according to claim 5 or 6, wherein the water blocking material is filled by performing high pressure injection from a rod directly inserted into the ground.   The method for constructing a retaining wall according to any one of claims 5 to 7, wherein the water blocking material is filled so as not to protrude in front of the pile material.   9. The method according to claim 5, further comprising a step of providing a plate material between the adjacent pile materials in a part of the pile material excluding the filling portion of the waterstop material in the height direction. The retaining wall according to any one of the above.

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