JP3552925B2 - Opening method of groundwater holes in steel pipe column retaining wall - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a method for restoring groundwater vein of a steel pipe column retaining wall formed for water stoppage and soil retaining when constructing an underground structure or the like, wherein a groundwater flow hole is provided in a soil cement portion under the steel pipe of the retaining wall. It is about how to establish.
[0002]
[Prior art]
In the construction of underground structures, etc., a well-impermeable soil retaining wall is constructed around the construction area to excavate the ground underground and to construct a building. Is buried. Since the embankment wall emphasizes water shielding, a continuous underground wall made of reinforced concrete and a steel tube column retaining wall are generally used.However, the formation of this wall will block the groundwater vein and increase the groundwater level. It often causes large fluctuations and adversely affects the surrounding environment. Particularly in recent years, this has become a social problem as construction has become larger.
[0003]
In order to solve this problem, various researches and developments have been made on measures for restoring groundwater veins on earth retaining walls. However, in the case of earth retaining walls made of reinforced concrete, construction of water passage is troublesome and requires a large amount of cost. In addition, in the case of a steel column pillar retaining wall, since the structure is difficult to change because a pre-made steel pipe is used, it has been considered unsuitable as a structure for restoring the groundwater flow.
[0004]
The present inventors proceeded with research and development of water permeability in a steel pipe column soil retaining wall having many advantages, such as excellent workability and excellent strength and water blocking properties, and were formed at the time of construction of the soil retaining wall by work from the ground. A method has been proposed in which a water passage hole is formed in the earth retaining wall made of only soil cement so that the flow of the groundwater vein can be restored (for example, see Japanese Patent Application No. 9-189002).
[0005]
[Problems to be solved by the invention]
The proposed method is to excavate and remove the soil cement inside and below the buried steel pipe from above the ground with an auger screw or the like to open a water hole. However, excavation with an auger screw requires a large pile driver, and because it excavates the inside of the steel pipe from the ground and proceeds with the excavation to the soil cement wall below it, it hits a groundwater vein that does not originally need to be excavated Excavations and removal of soil cement other than the part required a large construction space, and it was pointed out that there were disadvantages in construction and cost, such as excessive cost.
[0006]
The present invention has been made in order to solve the above-mentioned problem, and a relatively small water jet construction machine is used to excavate a necessary portion of a groundwater vein and a corresponding soil cement wall by a simple operation from the ground. It is intended to provide a new method of removing and opening a water hole.
[0007]
[Means for Solving the Problems]
The configuration of the present invention for achieving the above object, with reference to the accompanying drawings corresponding to embodiments, a method according to claim 1, in construction of a steel pipe Piles earth retaining wall A, the length of該土Tomekabe A It sets the range of the is passed through in the direction, the steel pipe 1 a which corresponds among water passage scope of the steel pipe 1 serving as earth retaining member, Tomeoki the sinking in to a depth near the upper end of the underground water vein D, other steel tube 1 is aquifer the by sinking depth in need beyond the bottom of the Tomeoi steel pipe to form a nonexistent soil cement only earth retaining wall 3 a of the steel pipe, after hardening of the soil cement, fastened by underground water vein D near A guide hole 6 is formed in the inserted steel pipe 1a, and a water jet nozzle 8 is inserted through the guide hole 6 to excavate and remove a water flow target area of the soil cement wall 3a. Water hole communicating with D 5 is established.
[0008]
The method according to claim 2 is a method according to claim 1, in which, when the soil cement is in a hardened state, the small-diameter vertically long formwork 11 is inserted into the steel pipe 1a kept close to the groundwater vein D. It is characterized in that holes 6 are formed.
[0009]
In the method of claim 3, in the construction of the steel pipe column retaining wall A , the depth of the steel pipe 1 serving as the retaining member is set to a depth equal to or less than the required penetration depth to the impermeable layer E below the groundwater vein D. comprising, formed on the earth retaining wall 3 a of only soil cement in the absence of the steel pipe 1, after curing of the soil cement, drilled guide hole 6 than in the steel pipe 1a above the water passage scope a, the guide hole 6 A water jet nozzle 8 is inserted into the soil cement wall 3a to excavate and remove a water flow target area , and a water flow hole 5 communicating with the groundwater vein D is opened in the soil cement wall 3a. is there.
[0010]
The method according to claim 4 is the method according to claim 3, wherein when the soil cement is in a hardened state, a small-diameter vertically long formwork 11 is inserted into the steel pipe 1a above the water-passing point a. It is characterized in that holes 6 are formed.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention relates to a steel pipe column retaining wall (hereinafter referred to as a retaining wall) that is constructed for impermeable and retaining soil when constructing an underground structure or the like, and communicates with the groundwater vein interrupted by the construction. This is to open a water hole.
[0012]
Conventionally, as shown in FIGS. 1, 2, 13, and 14, a steel pipe 1, 1 provided with a joint member 2 on the opposed outer surface is fitted and connected to each other by the joint members 2, 2. While being inserted into the excavation hole 4 filled with the soil cement 3, the operation is performed. This method is called a so-called ONS method.
[0013]
As shown in FIG. 1 and FIG. 2, the construction of the retaining wall A is such that the entire retaining wall A including the steel pipe 1 is inserted into the impermeable layer E below the groundwater vein and over the groundwater vein. As shown in FIGS. 13 and 14, the steel pipe 1 to be laid is of a length necessary for the stability calculation of the retaining wall A. In order to make the retaining wall A function as a water impervious wall, In some cases, a soil cement wall 3a in which only the soil cement 3 is filled in the excavation hole 4 is formed at a depth deeper than the lower end of the steel pipe 1 in which the steel pipe 1 is laid and beyond the permeable layer to the impermeable layer E thereunder.
[0014]
The method (first method) corresponding to Claims 1 and 2 is carried out on the former soil retaining wall A formed by piercing the steel pipe 1 to the impermeable layer E. A corresponding method (second method) is carried out in the latter, a retaining wall A which is formed by embedding the wall 3a of only soil cement below the laid steel pipe 1 into the impermeable layer E.
[0015]
First, an embodiment of the first method will be described. As shown in FIGS. 1 and 2, the retaining wall A is formed with the construction ground C interposed therebetween. In the first method, when constructing the retaining wall A, a range (a target area for water transmission) a is set in the longitudinal direction of the retaining wall A, and the steel pipe 1a corresponding to the range a is set at the upper end of the groundwater vein D. The steel pipe 1 is laid in the impermeable layer D beyond the permeable layer in the same manner as in the prior art so as to keep the sediment in the soil cement close to the depth. Therefore, in the water flow target range a, the portion below the steel pipe 1a is only the soil retaining wall (soil cement wall) 3a made of only soil cement having no steel pipe as a core material.
[0016]
Then, a water hole 5 (see FIGS. 3 and 4) communicating with the groundwater vein D is opened in the soil cement wall 3a. As shown in FIGS. 5 and 6, after the soil cement 3 is hardened, the water passage hole 5 is first opened from the inside of the steel pipe 1 a within the water passage target area a set in the longitudinal direction of the retaining wall A. A guide hole 6 having a diameter small enough to insert a jet nozzle is formed, and the soil cement 3 in the upper portion of the steel pipe 1a is removed to form a recess 7. In the illustrated example, the guide hole 6 is provided to a depth reaching near the lower end of the groundwater vein D. However, the present invention is not limited to this. For example, the guide hole 6 may reach the lower end of the steel pipe 1a. Good.
[0017]
Next, as shown in FIGS. 7 and 8, a high-pressure water injection pipe 9 having a nozzle 8 at the tip is inserted into the guide hole 6, and high-pressure water is injected to the soil cement wall 3a at a position intersecting with the groundwater vein D. And crush and excavate. The excavated soil cement is discharged together with the water from the guide hole 6 to the upper concave portion 7 and to the ground. Then, the soil cement and the water that have reached the concave portion 7 are sucked by the suction pipe 10 and discarded at an appropriate place. As a result, a water hole 5 communicating with the groundwater vein D is opened in the soil cement wall 3a, and the groundwater vein D blocked by the retaining wall A is replaced with the soil vein formed with the construction ground C therebetween. The water flow is restored via the water holes 5, 5 in the walls A, A.
[0018]
9 to 11 show another embodiment of the opening of the water hole 5. In this embodiment, when the soil cement is in an unhardened state after the formation of the retaining wall A, as shown in FIG. 9, for example, the tip is closed from the ground in the steel pipe 1a in the water passage target area a. A bottom, small-diameter, vertically long pipe-shaped mold (or a solid rod-shaped mold) 11 is inserted, and when the soil cement 3 is hardened or almost hardened, the mold 11 is pulled out and removed. Thereby, as shown in FIG. 10, the guide hole 6 is formed in the soil cement from the steel pipe 1a to the groundwater vein D. Thereafter, as in the previous embodiment, the nozzle 8 is inserted into the guide hole 6 and excavated by a water jet, and the soil cement and water are discharged through the suction pipe 10 to open the water passage hole 5. become. In this embodiment, similarly to the previous embodiment, the depth of the guide hole 6 may be such that it reaches the lower end of the steel pipe 1a.
[0019]
In each of the above embodiments. Although the number of the steel pipes 1a in the water passage target range a is one, this can be implemented even when a plurality of steel pipes are connected as shown in FIG. 12, for example. By doing so, the water passage hole 5 can be made large.
[0020]
Next, the second method will be described. This retaining wall A is also formed with the construction ground C sandwiched in the same manner as in the first method described above, but the retaining wall A in the second method is laid down as shown in FIGS. The steel pipe 1 has a length necessary for calculating the stability of the retaining wall. However, in order to provide the retaining wall A with a function as a water impervious wall, the retaining pipe made of only the soil cement filled in the excavation hole 4 (soil cement) is used. A wall 3a is formed at a depth beyond the groundwater vein D to the impermeable layer E thereunder. The water hole 5 is formed in the soil cement wall 3a.
[0021]
The opening of the water hole 5 is performed in the same manner as the opening of the water hole 5 in the first method. That is, as one embodiment, as described with reference to FIGS. 5 to 8, after the soil cement was hardened, the guide hole 6 was formed from the steel pipe 1 a in the water flow target range to the soil cement wall 3 a. Then, the water hole 5 is opened by a water jet. As another embodiment, as described with reference to FIGS. 9 to 11, when the soil cement is in an uncured state, the mold 11 is inserted and pulled out, and after forming the guide hole 6, the water is removed. The water hole 5 is opened by the jet.
[0022]
In each of the above embodiments, the number of the steel pipes 1a in the water passage target area a is one. However, the second method is similar to the case of the first method, for example, as shown in FIG. A large water passage hole 5 can be opened in the soil cement wall 3a by extending the water passage target area a so as to extend over a plurality of steel pipes and passing through the steel pipes 1a therein.
[0023]
【The invention's effect】
As described above, according to the present invention, in the construction of an underground structure or the like, a steel pipe column row retaining wall conventionally buried and buried as a high water-impermeable retaining wall is used, and the presence of a steel pipe is provided below the column. A soil retaining wall made of only soil cement is formed and a water hole is opened in it.The steel pipe column retaining wall functioning as a water impervious wall at the time of construction, and the groundwater vein restored after construction It can function as a water-permeable wall.
[0024]
And even in the construction where the entire retaining wall is embedded into the impermeable layer, and also in the construction in which the soil cement wall below the column steel pipe goes beyond the permeable layer into the impermeable layer, Since the water holes can be opened by a relatively small water jet construction machine without using a large construction machine, the construction space can be reduced, and the construction can be performed simply and economically. In addition, the cleaning effect of the water jet can also remove cement milk that has infiltrated into the ground, thereby reliably restoring groundwater veins.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a state in which a retaining wall is formed in an embodiment of the first method of the present invention.
FIG. 2 is a partial front view of the earth retaining wall.
FIG. 3 is a side sectional view showing a state in which the water hole is opened.
FIG. 4 is a partial front view of the earth retaining wall.
FIG. 5 is a side sectional view of a main part showing a guide hole formation state in an embodiment of opening a water passage hole.
FIG. 6 is a front sectional view of the essential part.
FIG. 7 is a sectional side view of a main part showing a state of the water jet injection.
FIG. 8 is a front sectional view of the relevant part.
FIG. 9 is a cross-sectional side view of a main part showing a form insertion state in another embodiment in which a water-permeable hole is opened.
FIG. 10 is a sectional side view of a main part showing a state in which the guide hole is formed.
FIG. 11 is a sectional side view of a main part showing a state of the water jet injection.
FIG. 12 is a front view of a main part showing another embodiment of the first method.
FIG. 13 is a sectional side view of a main part showing an embodiment of the second method of the present invention.
FIG. 14 is a front view of the same.
FIG. 15 is a front view of a main part showing another embodiment.
[Explanation of symbols]
A Steel pipe column retaining wall B Underground structure C Construction ground D Groundwater vein E Impervious layer 1, 1a Steel pipe 2 Joint material 3 Soil cement 3a Soil cement wall 4 Drilling hole 5 Water hole 6 Guide hole 7 Recess 8 Nozzle 9 High pressure Water injection pipe 10 Suction pipe 11 Formwork

Claims (4)

In the construction of the steel column pillar retaining wall, set the range to allow water to flow in the length direction of the retaining wall, and lay down the steel pipe that is the target area of the steel pipe as the retaining member to a depth near the upper end of the groundwater vein. The other steel pipes are sunk to the required depth beyond the permeable layer, and the lower part of the steel pipes is formed on the retaining wall made of only soil cement without steel pipes. A guide hole was drilled from the steel pipe that was kept up to the point, and a water jet nozzle was inserted into this guide hole to excavate and remove the target area of the soil cement wall for water penetration. A method for opening a groundwater flow hole in a steel pipe column retaining wall, characterized by opening a water hole for communication. In the construction of the steel column pillar retaining wall, when the soil cement is in an unhardened state, a guide hole is formed by inserting a small-diameter vertical formwork into the steel pipe kept close to the groundwater vein, The method for establishing a groundwater passage hole in the steel pipe column retaining wall according to claim 1. In the construction of a steel column pillar retaining wall, the depth of the steel pipe used as the retaining member should be reduced to the required penetration depth beyond the groundwater vein to the impervious layer below it. After forming and hardening the soil cement, a guide hole is drilled from the steel pipe above the water flow target area , and a water jet nozzle is inserted into this guide hole to increase the water flow target area of the soil cement wall. A method for opening a groundwater drainage hole in a steel pipe column soil retaining wall, comprising excavating and removing and opening a drainage hole communicating with a groundwater vein in a soil cement wall. In the construction of the steel column pillar retaining wall, when the soil cement is in an uncured state, a guide hole is formed by inserting a small-diameter vertically long formwork into the steel pipe above the water flow target range , The method for opening a groundwater passage hole in the steel pipe column retaining wall according to claim 3.

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