JPH0641977A - Construction method of continuous underground water stop wall - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent deterioration of the stabilizing liquid to be used, and to construct a continuous water blocking wall that is easy to build and connect water blocking sheets and has excellent workability and water blocking performance. [Structure] An excavation groove 6 is formed in the ground while using a wall stabilizing liquid 5, and a connecting fitting 2a having substantially the same depth as the excavation groove depth on both sides of the excavation groove 6,
After the bag 1 made of a liquid-impermeable sheet provided with 2b is built in a contracted state, a filling material is injected into the bag 1,
A continuous water blocking wall W covered with a liquid impermeable sheet is constructed in the excavation groove 6. The bag body 1 is slightly shorter than the connecting metal fitting, and the connecting metal fitting is in a state in which the extra length of the relative difference is projected downward. A space M is formed and the connecting fitting 2
An injection rod is inserted through the vertical hole space P formed by a and 2b, and the lower space M is filled with grout material to perform root consolidation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing a continuous water stop wall which is constructed in the ground as a water stop wall in a construction work, a dam continuous water stop wall, a hazardous substance flow prevention wall and the like.

[0002]

2. Description of the Related Art As a method for constructing a water blocking wall in the ground, there is an underground continuous water blocking wall method which has been widely used in recent years.
This underground continuous water-stop wall construction method uses a high-pressure jet to form a groove in the ground, injects asphalt emulsion and cement grout into the space, improves the ground, and protects the groove wall. While using a bentonite stabilizer, etc., after excavating a groove of a predetermined depth in the ground, pour asphalt emulsion, cement-based grout material, etc. into the excavation groove, or put a curing agent in the stabilizer. There is a method of constructing a continuous water blocking wall in the ground by naturally hardening it.

In order for the wall body constructed by the continuous water-stop wall construction method to fully function as a water-stop wall, the wall body is free from cracks and the watertight structure of the joint portion is excellent. However, in reality, due to uncertainties in construction, excessive stress cracks caused by earthquakes, etc., complete waterproofing cannot be expected over a long period of time, so a waterproof sheet was used. The continuous water stop wall method is adopted. As a continuous water-blocking wall method developed in recent years, for example, Japanese Patent Laid-Open No. 4-5094 and Japanese Patent Publication No. 61-494.
51, JP-A-63-304821, JP-A-56-85018, and JP-A-63-522.

[0004]

However, the main construction method of the continuous water-stop wall construction method using the water-stop sheet is that one sheet of water-stop sheet is built in the excavation groove, and then the curing agent is applied to the front and back sides thereof. However, there are various construction problems when installing the waterproof sheet. For example, when the water blocking sheet is built in the stabilizing solution, it cannot be lowered by its own weight. Therefore, as in the invention described in JP-A-56-85018, columns are attached to both ends of the water blocking sheet. A method of making a descent has been proposed. In this case, the pillars are temporarily suspended by a crane or the like, and then they are built in the vertical direction, but there is a limit to the lateral length of the seat that can be accurately built. Further, as described in Japanese Patent Laid-Open No. 63-304821, there has been proposed a method in which a water blocking sheet is stretched between a plurality of struts and is installed in a laterally compact state. However, as the excavation depth increases, it becomes difficult to accurately stretch the waterproof sheet in a compact size. Furthermore, when connecting between the water blocking sheets, the water blocking sheets must be installed and connected in an open state, and this connection work is difficult and requires a lot of labor and time.

On the other hand, when constructing a continuous wall, the excavation trench is sequentially constructed for each predetermined block (element) unit, but various problems occur in relation to the wall stabilizing liquid used. If the bentonite stabilizer is used, when excavating the next unit adjacent to the unit that has already been hardened with a cement-based hardening agent, the bentonite stabilizer is contaminated by calcium ions of the hardening agent. Deteriorates and causes the wall to collapse, and the amount of waste liquid increases, and bentonite adheres to the wall and joint of the already hardened adjacent unit, resulting in the formation of unconsolidated parts and water leakage. There was a problem such as. Further, the deterioration of the bentonite stabilizing solution increases the gel viscosity and the specific gravity, which lowers the excavation efficiency and makes it difficult to classify the sludge, install the water blocking sheet, and solidify. Also,
When a self-curing stabilizer is used, it is restricted by various operations such as excavation and installation of a waterproof sheet due to restrictions from the curing time, and gel viscosity and specific gravity increase due to deterioration of the self-curing stabilizer, The above-mentioned problems similarly occur. further,
When a polymer stabilizer is used, there are problems such as difficulty in curing itself.

[0006] Therefore, the main object of the present invention is to eliminate the deterioration of the stabilizing solution used, and solve the various problems that have arisen with it, and to install the waterproof sheet.
It is intended to provide a method of constructing a continuous water blocking wall which facilitates connection work and is excellent in workability and water blocking performance.

[0007]

[Means for Solving the Problems] The problem is to form an excavation groove in the ground while using a wall stabilizing liquid, and to make the excavation groove slightly shorter than the depth of the excavation groove, and to provide both side portions thereof. A bag body made of a liquid-impervious sheet having a length substantially equivalent to the groove depth and provided with a connecting metal fitting projecting an extra length of the relative difference downward is built in a contracted state. After that, a filling material is injected into the bag body to form a continuous water blocking wall covered with a liquid impermeable sheet in the excavation groove, and at the connecting portion connecting adjacent water blocking walls to each other. A vertical hole space in the depth direction of the ground is secured by the connecting fitting, an injection rod is inserted from the vertical hole space, and a grout material is provided in the space between the bag body and the bottom of the excavation groove supported by the connecting fitting in a floating state. It is possible to solve it by filling and solidifying.

[0008]

In the present invention, the water blocking sheet is a bag made of a liquid impermeable sheet. This bag body is slightly shorter than the depth of the excavation groove, has a length substantially corresponding to the groove depth on each of both sides thereof, and a connecting fitting in which an extra length of the relative difference is projected downward. It is equipped with. First, when installing in the excavation ditch, since the connecting metal fittings fixed to both sides of the bag body are used as the core material to contract the bag body and insert it in a compact and solidified state, it can be easily installed. In addition to being able to do so, the connecting work can be performed easily. Once the bag is built,
A filling material is injected into the bag body to form a water blocking wall covered with a liquid impermeable sheet in the excavation groove. The injected filler is completely separated from the wall stabilizing liquid used for excavation and does not mix with each other, so the contamination of the wall stabilizing liquid is eliminated, and various problems that have been problems in the past are solved. It Further, since the filler can be quality-controlled on the ground, strength and quality can be arbitrarily adjusted, and since slime and the like are not mixed in, it is possible to construct a water blocking wall having a desired quality. Become. If a bag having a partition wall or a plurality of connecting members arranged in the groove width direction is used inside the bag, the shape can be retained relatively easily even in the injection completed state and the expansion in the excavation groove width direction can be achieved. You can prevent it from coming out.

Further, in the case of the conventional construction method, the wall body is constructed by filling the grout material, adding a curing agent to the wall surface stabilizing liquid to cure, or waiting for the self-hardening stabilizing liquid to cure. Therefore, it was not possible to excavate until the adjacent element has a predetermined strength, but in the case of the method of the present invention, the bag is filled with a filler, so There are no restrictions and continuous work can be performed, and interlocking pipes and the like are not required to be built, which improves work efficiency. Further, in the present invention, a vertical hole space in the depth direction is secured by the connecting fitting at a connecting portion connecting adjacent water blocking walls, an injection rod is inserted from the space, and is supported by the connecting fitting in a floating state. Since the grout material is filled in the space between the bag body and the bottom of the excavation groove, which is solidified, a reliable and highly reliable water blocking wall can be constructed.

[0010]

EXAMPLES The present invention will be described in detail below based on examples. FIG. 1 is a diagram of a rooting construction procedure in a continuous underground water blocking wall according to the present invention, FIG. 2 is a diagram showing the impermeable bag 1 according to the present invention in a built-up state, and FIGS. [Fig. 5] is a structural diagram of the bag body 1, and Fig. 5 is a diagram showing an injection construction procedure after being built. The liquid-impervious bag body 1 used in the method of the present invention is
A rectangular parallelepiped bag made of a suitable liquid-impermeable sheet material such as a polyethylene sheet, a nylon sheet, a canvas sheet or the like, or a synthetic rubber, etc., and a side wall sheet portion as shown in FIG. Is folded in a bellows shape and inserted in a contracted state. Further, the bag body 1 is slightly shorter than the depth of the excavation groove, and male and female connecting fittings 2a and 2b each having a length substantially equivalent to the depth of the excavation groove are fixedly provided on both sides thereof. ,
The connecting fittings 2a and 2b are legs that protrude downward with an extra length of relative difference from the bag body 1. The connecting fitting 2
When a steel material is preferably used as a and 2b, it serves as a core material of the bag body 1 and functions as a weight, which facilitates transportation and installation. The bag 1
The inside of the cell is divided into a plurality of cells 1A to 1F by partition walls 1a to 1e arranged in the groove width direction in the direction of the completed construction. The partition walls 1a to 1e are shown in FIG.
As shown in Fig. 4, when the surrounding ground is soft or relatively weak, the bag body 1 is prevented from bulging in the groove width direction as shown by the chain line, and the bag body 1 is rectified even after the injection. It is provided so as to retain the shape of.
Further, injection holes 1f, 1f ... Are formed in the ceiling sheet portions of the cells 1A to 1F, respectively.
The filler is sequentially injected into F, and when the injection is completed, as shown in FIG.
It becomes the shape shown in. The size B of the bag 1 and the cell division are determined after careful consideration of the workability, the work process, the extension of work per day, and the like. The partition walls 1a to 1e do not have to be sheet materials for completely partitioning the cells 1A to 1F as shown in FIG.
As shown in FIG. 6, the partition walls 1a, 1c, and 1e may be, for example, a mesh sheet or a connecting member provided at appropriate intervals so as to allow the flow between the cells.

In constructing a ground suspension water wall, first, in accordance with the general procedure for trench excavation, a pair of guide walls 4 and 4 form a trench by taking measures such as a ruler for trench excavation, protection of hole walls, and prevention of stabilizing liquid outflow. After sandwiching and laying, the excavator which is appropriately selected such as bucket type, impact type or rotary type is used to excavate the excavation trench 6 while filling the excavation trench 6 with the wall surface stabilizing liquid 5. In the case of excavation, the method of the present invention allows continuous construction without waiting for the hardening of the adjacent walls, and therefore the excavation order is not limited at all, and the excavation can be performed continuously in one direction.

Next, the bag 1 is built from the portion where the trench excavation is completed. At the time of building, as shown in FIG. 2, the bag 1 is suspended by a heavy machine (not shown) such as a crane brought to the site, and is built in the vertical direction as it is. At that time, the completed water blocking wall W
The female connecting fitting 2b of the built-in bag 1 is fitted into the male connecting fitting 2a fixed to the side end of (1 '), and is suspended as a guide.

When the building of the bag 1 is completed, the filling material is injected according to the procedure shown in FIG.
If the extension direction of the wall is to the right of the drawing, then FIG.
As shown in (c), the leftmost cell 1A of the bag 1 is filled. The cell 1A expands as the filling material is injected, and the portion of the bag 1 on the right side of the cell 1A is pushed out to the right side of the groove 6. Next, as shown in FIG. 5D, the filling material is sequentially injected into the cells 1B and 1C from the left side cell to extend to the right side of the groove 6 and the space between one element is increased as shown in FIG.
As shown in, a water blocking wall W covered with a liquid impermeable sheet is constructed. When the bag 1 is built, as shown in FIG. 2, a method may be used in which it is connected to the completed bag 1 ′ at the time of building, or a plurality of bags 1, 1 ... It is also possible to assemble these into a groove after connecting them together.

As the filler to be injected into the bag body 1, for example, asphalt emulsion, cement-based milk, mortar, concrete or the like can be preferably used, and since it simply has only the function of stopping water. If it is possible to use water, waste liquid, liquid such as sand, or granular material. Further, in order to reduce the amount of industrial waste, it is possible to fill the bag body 1 with the replacement portion of the bentonite stabilizing solution used at the time of excavation as it is or with a curing agent mixed therein. In addition, the injection may be performed by pouring or by press-fitting with a predetermined pressure.

On the other hand, under the condition that the construction depth of the water blocking wall is shallow or the ground is relatively strong, the bag body 7 shown in FIGS. 7 and 8 can be used. The bag 7
Is a rectangular bag having no partitioning material such as partition walls,
Similar to the bag body 1, it has connecting fittings 2a, 2b on its side parts, and an injection hole 7a in its ceiling sheet part, and when assembled, it is folded into a bellows shape as shown in FIG.
It is inserted in a contracted state, and the filling material is injected according to the same procedure as that of the bag body 1.

By the way, in the connection portion of the water blocking wall W in the present invention, a vertical hole space P in the depth direction of the ground is formed by the connection fittings 2a, 2b, ... Specifically, in the case of the bags 1 and 7 shown in FIGS. 3 and 7, a steel material having a T-shaped cross section is used for the male connecting fitting 2a, and an opening groove is formed laterally for the female connecting fitting 2b. By using the steel material having a box-shaped cross-section, the vertical hole space P in the depth direction of the ground is secured in a state where these connecting fittings are connected to each other. As a concrete shape of the other connecting metal fitting, for example, as shown in FIG. 9, the connecting arms 11a and 1a are provided on the left and right sides of the bag body 10, respectively.
It is also possible to use a connecting fitting 11 (12) having a U-shaped cross section in which 1b (12a, 12b) is fixedly installed, and FIG.
As shown in 0, on both sides of the bag body 13,
H-shaped sheet pile 14, 1 with one side of the flange cut
5 can also be used. The connection fittings 2a, 2b, 1
.. function as a weight when the bags 1, 7 are built, facilitate the building in the excavation trench, and function as a protective material for the bags when sliming. Also,
By these, the vertical planes of the side edges on the extension side of the bags 1, 7 ... Are secured and the mutual connection is facilitated.

As shown in FIG. 1, the bag body 1 according to the present invention is provided with connecting metal fittings 2a fixed to both sides in the installed state.
When the tip of 2b contacts the bottom of the excavation groove, it is supported above the bottom of the excavation groove and is supported in its lower space M.
On the other hand, grouting material such as mortar or concrete is filled and root consolidation is performed. At the time of root consolidation, the injection rod 15 is inserted through the vertical hole space P formed by the coupling fittings 2a, 2b, and the bentonite solidifying material is inserted from the tip nozzle of the rod 15 toward the lower space M of the bag body 1, or Grout materials such as cement milk, mortar, or concrete are pressed in. The grout injection pressure of 30 kgf / cm ² or more, preferably about 50 kgf / cm ² or more is sufficient. The injected grout material is not limited to the lower space M of the bag body 1 and the partition walls 1a. 1
Since it also enters the vertical grooves 6a, 6a ... of the b portion, a sufficient waterproofness is secured. In addition, instead of the injection rod 15, a tremie pipe is used to replace the concrete with the lower space M.
It can also be set in. It seems that even the concrete can be filled in the lower space M due to its fluidity. Further, when pouring and placing grout material or the like, as shown in FIG. 11, for example, the bentonite stabilizing solution is pumped up from the vertical hole space P on one side and introduced into the vertical hole space P on the other side for circulation. Create a flow,
It is also possible to make the grouting material or the like that is poured and placed around the lower portion of the bag body 1 good. In particular, when the distance between the joints is long, it is a relatively effective method when pouring concrete.

On the other hand, in constructing the water blocking wall, it is necessary to remove slime after excavation, but as shown in FIG. 12, the slime S in the adjoining portion of the bag body 1 is temporarily removed by the clamshell bucket 9 as shown in FIG. In the case of removing, as shown in FIG. 13, if the removing work is performed while protecting the bag body 1 after being built by the protective steel material 8 having a U-shaped cross section, the bag body 1
You can work without damaging. The protective steel material 8 can also be used as a jig for building.

The lateral movement associated with the injection of the filler into the bag 1 described above will now be described. As shown in FIG. 14, the specific gravity of the wall surface stabilizing liquid 5 filled in the groove 6 is If γ _s , the pressure distribution in the depth direction is represented by γ _s · H. On the other hand, assuming that the specific gravity of the filler injected into the bag body 1 is γt, the pressure distribution in the depth direction is also represented by γt · H.
Usually, the specific gravity of the bentonite liquid used as the wall stabilizing liquid is in the range of about 1.15 to 1.25, and when the filler is cement-based, it is in the range of about 1.30 to 1.70. Therefore, the pushing force (γt−γ _s ) · H due to the difference in specific gravity acts as the pressure ΔP in the pushing direction. Therefore, it is considered possible to sufficiently push laterally by using the additional pressure due to the difference in specific gravity, the injection pressure, and the like as necessary. In some cases, if the upper end A of the bag body 1 on the side of the moving tip side is injected in a timely and restrained manner by some method, the pressure on the lower end side can be increased and the movement can be facilitated. it can.

[0020]

As described above in detail, according to the continuous water blocking wall of the present invention, it is possible to eliminate the deterioration of the stabilizing liquid used and solve the various problems caused by the deterioration. Further, the work of constructing and connecting the water blocking sheet is facilitated, and the workability and the water blocking property are excellent.

[Brief description of drawings]

FIG. 1 is a diagram of a rooting construction procedure for an underground continuous water stop wall according to the present invention.

FIG. 2 is a diagram showing a state in which the bag body 1 according to the method of the present invention is installed.

FIG. 3 is a contracted state diagram of the bag body 1.

FIG. 4 is a state diagram of the bag body 1 after the filling material is injected.

FIG. 5 is a diagram showing an injection procedure after the bag is built.

FIG. 6 is a functional explanatory diagram of a partition wall.

FIG. 7 is a contracted state diagram of a bag having a one-cell structure.

FIG. 8 is a view showing a state where a bag having a one-cell structure is filled with a filler.

FIG. 9 is a contracted state diagram of a bag body including another connecting fitting.

FIG. 10 is a contracted state view of a bag body including another connecting fitting.

[Fig. 11] Fig. 11 is a construction status diagram of a rooting work.

FIG. 12 is a slime treatment procedure diagram.

FIG. 13 is a bag body protection state diagram during slime processing.

FIG. 14 is an explanatory diagram of lateral movement of the bag body.

[Explanation of symbols]

1. 7 ... bag body, 1a to 1e ... partition wall, 1f ... injection hole, 2a
・ 2b ... Connection fitting, 4 ... Guide wall, 5 ... Wall stabilizing liquid, 6 ... Excavation groove, 8 ... Protective steel material, 9 ... Clamshell bucket, W ... Water blocking wall

Claims (1)

[Claims] 1. An excavation groove is formed in the ground while using a wall stabilizing liquid, and the excavation groove is slightly shorter than the excavation groove depth, and the groove is substantially formed on each of both sides of the excavation groove. After building a bag made of a liquid-impermeable sheet in a contracted state, having a length corresponding to the depth and having a connecting metal fitting projecting the extra length of the relative difference downward, the bag is placed inside the bag. Injecting a filler to form a continuous water stop wall covered with a liquid impermeable sheet in the excavation trench, and in the connecting portion connecting adjacent water stop walls, the connecting metal fittings in the ground depth direction A vertical hole space was secured, an injection rod was inserted from the vertical hole space, and the space between the bag body and the bottom of the excavation groove supported in a floating state by the connecting metal fitting was filled with grout material to perform root consolidation. A method of constructing a continuous underground water stop wall, which is characterized in that