JPH08260452A - Cylindrical drain structure and method of weak-ground improving construction by cylindrical drain structure - Google Patents

Abstract

PURPOSE: To improve drainage performance by fitting a beltlike drain body on the peripheral wall of a cylindrical coating body and preparing a pile while using industrial waste as fillers to a water-permeable cylindrical drain body mounted so as to be crossed with the beltlike drain body. CONSTITUTION: A plurality of thin beltlike drain bodies 2 in narrow width are installed in parallel on the outer circumferential wall surface of a cylindrical coating body 1 from an end to an end along a bus direction. The mounting ratio of the beltlike drain bodies 1 in narrow width to the outer circumferential surface of the cylindrical coating body 1 is changed in response to the extent of the water permeability of fillers charged into the cylindrical coating body 1. When water permeability can depend upon sand pile itself largely, moisture pressed in the ground is passed through the water-permeable cylindrical coating body 1 and collected by the fillers having water permeability on the inside and drained. When the water permeability of the fillers charged into the cylindrical coating body 1 cannot be expected so much, the fillers conduct action, in which the weak ground is pressed in the horizontal direction and moisture in the ground is pressed and collected to the beltlike drain bodies 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical drain structure for forming sand piles for improving soft ground and a soft ground improving method using the same.

[0002]

2. Description of the Related Art It is a conventional practice to construct vertically permeable sand piles in soft ground and apply a load to the ground to collect water in the ground into the sand piles and squeeze it to strengthen the ground. It is widely used as a sand drain method. By the way, on the ground that is extremely likely to collapse, on soft ground or on soft ground immediately after landfill, the sand piles that have been constructed will cause the surrounding ground to collapse, or excessive porosity or soil that will be generated in the soil when hollow pipes are laid. It may be locally deformed or bent due to pressure or the like, and when it is extremely severe, it may be cut in the middle and the initial purpose may not be achieved.

Therefore, the periphery of the sand pile is covered with a tubular structure formed of a water-permeable material such as paper, a porous plastic sheet, a net, and a non-woven fabric so that the shape of the sand pile is maintained from the soft ground. The technology (see Patent Application Publication No. 3006 of 1970) was developed. This technique thus achieves the purpose of ground reinforcement by sand piles.

When a long tubular structure made of a net material made of synthetic resin is used as the water-permeable material, the long tubular structure is inserted into a hollow pipe which has been previously driven into the ground and the sand is inserted. However, at this time, the elongated tubular structure is caused to sway or twist in the middle due to the weight of sand, and becomes a twisted state, which makes subsequent sand filling and insertion work impossible. There was a possibility that the purpose of sand pile construction could not be achieved.

Therefore, the reinforcing ears are formed symmetrically along the generatrix direction on the outer peripheral surface of the long tubular structure to further enhance the strength of the tubular structure, and the long tubular structure is not fully formed during the construction. Bag for synthetic resin mesh sand piles (Showa 48) that prevents swiveling and twisting from occurring.
Year Utility Model Application Publication No. 24975) has been devised. The sand pile using this bag for sand pile construction also creates a drainage channel in the vertical direction to smoothly suck up the water in the ground and drain it to promote the consolidation of the ground. ing.

From the description of the construction condition of the sand pile forming bag, if the forming bag is swung or twisted during the charging of the filler, it means that the length of the bag is The hollow pipe is larger than the diameter, and the inner diameter of the hollow pipe is at least the outer diameter of the bag for sand pile formation, plus the width of both reinforcing ears, so the hollow pipe is driven into the ground. The ratio between the cross-sectional area and the cross-sectional area of the constructed sand pile becomes relatively small,
There is a problem that construction efficiency is low and the effect of applying load to the ground per unit is diminished. By the way, in recent years, there is a shortage of high-quality fillers such as river sand, which may hinder the promotion of the consolidation effect of the vertical drain method, which may cause various troubles in the soft ground improvement work.

Therefore, a part of the water-impermeable net bag body that covers the sand pile is knitted with a thread made of a water-permeable material, and the water-permeable material portion of the net bag body is attached to the lower end of the net bag body. It is not possible to drain the water collected from the soft ground through the sand in the net bag by using the net bag structure for sand pile formation that is continuous from Of course, drainage is also carried out through the vertical permeable material provided in the main body of the net bag to promote the consolidation effect of the soft ground (public utility model application publication No. 8202 in 1992).
No. 9) are also known.

Further, in order to make up for the insufficient drainage function of the sand pile when using a sand pile forming (filling) material that causes a hindrance to the drainage function of the sand pile, it is necessary to form a vertically elongated tubular sand pile. Water-permeable bag structure for sand pile formation in which one or more water-permeable elongated drainage pipes are arranged along the longitudinal direction of the bag of the bag structure (see Japanese Patent Application Publication No. 198513/1992).
Is also known before application. The sand pile of this kind structure, during construction,
It is considered difficult to fill only the water-permeable bag structure with sand. In addition, one or more water-permeable drainage pipes that can withstand pressure from the outside have a literally circular cross section, and one bag is relatively flat, and both are integrated and integrated. To do this, a strong jig is required.

Further, when considering the cross section in the hollow pipe, the bag structure formed by integrating both of the above is a water distribution pipe (external) which holds an annular shape located on the outer periphery of the bag (that is, near the inner wall of the hollow pipe). It is understood that there is an inconvenience that the loss cross-sectional area of the formed sand pile is increased due to the water pipe having a strength capable of withstanding the pressing force from the above, and the deployment of the water pipe is also viewed from the surrounding ground. It can be seen from the viewpoint of the molded sand pile that it only has a drainage function as a point.

[0010]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems in the conventional structure and construction method, and improves the shape retention of the cylindrical drain structure and the filling efficiency of the filler. To increase the drainage performance of the structure itself, and to ensure that the type and range of materials that can be used as the filling material of the cylindrical drain structure are expanded.

[0011]

In order to achieve the above-mentioned object, the present invention has the respective constituent features as described below. (1) One or a plurality of strip-shaped drain bodies are provided on the inner or outer wall of a tubular or bag-shaped covering formed by a sheet-like material using a braided, woven or water-permeable material. A tubular drain structure. (2) The one or more band-shaped drain bodies provided on the inner or outer wall of the tubular or bag-shaped covering body are arranged continuously in the vertical direction or the diagonal direction, respectively. The cylindrical drain structure according to the item.

(3) One or a plurality of strip-shaped drain bodies provided on the inner or outer wall of the tubular or bag-shaped covering body are arranged in combination in the vertical direction and the diagonal direction, respectively. The cylindrical drain structure according to the item 1). (4) Item (1) above, wherein the one or more strip-shaped drain bodies provided on the inner or outer wall of the tubular or bag-shaped cover are arranged so as to cross each other diagonally. The cylindrical drain structure described. (5) One or a plurality of strip-shaped drain bodies provided on the inner or outer wall of the tubular or bag-shaped covering body are continuously arranged in the vertical direction or diagonal direction, and at least adjacent strip-shaped drain bodies are horizontally arranged. The cylindrical drain structure according to the above (1), which is arranged so as to communicate with.

(6) The tubular drain structure according to the above (5), wherein the horizontal band-shaped drain bodies are arranged in a continuous annular shape. (7) As a belt-shaped drain, the thickness is several mm and the width is 5
The above items (1) to (6) characterized in that the length is 20 cm
The cylindrical drain structure according to any one of items. (8) The tubular drain structure according to any one of (1) to (7) is inserted into a hollow pipe that penetrates into the ground, and sand or sand is inserted into the tubular drain structure. A method for improving soft ground, characterized in that a pile surrounded by a drain structure is formed in the ground by filling with a similar powdery material and extracting the hollow tube.

(9) The tubular drain structure according to any one of the above items (1) to (7) is inserted into a hollow pipe that penetrates into the ground, and the tubular drain structure is inserted into the tubular drain structure. A soft ground improvement method characterized by forming a pile surrounded by a drain structure in the ground by filling a soil material containing a cohesive soil such as an intermediate soil and extracting the hollow tube. (10) In the hollow pipe that penetrates into the ground, the above (1)
Through (7), the tubular drain structure according to any one of the items (1) to (7) is inserted, and the hollow drain is filled with industrial waste such as construction soil and coal ash while being inserted into the tubular drain structure. A soft ground improvement method characterized by forming a pile surrounded by a drain structure in the ground by extracting.

[0015]

The connection between the water-permeable band-shaped drain body and the cylindrical covering body in the longitudinal axis direction may be a crimping or nailing structure. Particularly, when they are connected in parallel in the longitudinal axis direction, Simply connecting the ends to each other ensures simple connection at other points. The cylindrical drain structure of the present invention is formed by connecting the band-shaped drain body to the cylindrical covering body in advance before it is carried into the site, and by carrying it in separately and assembling it on site before the construction. There could be ways, but

The thin band-shaped drain body has elasticity in the longitudinal axis direction, is relatively difficult to bend, and can be easily bent in the width direction. Therefore, the two are coupled to each other in the respective longitudinal axis directions. If it is, it can be folded in the width direction after assembly and can be transported with a small volume, and it is planned to attach the band-shaped drain body to the cylindrical covering body in a circumferential or diagonal direction. In some cases, on-site connection before construction is convenient for carrying in.

The strip-shaped drain body is, as described above,
Since it is a material that has elasticity in the longitudinal axis direction and is relatively difficult to bend, the tubular or bag-shaped covering body acquires shape retention by mounting it on the cylindrical covering body, and therefore Insert the coating in a hollow tube that has penetrated,
Even when the filler is put therein, there is no possibility that the covering body is bent or twisted, and the filler can be packed efficiently and surely.

Since the belt-shaped drain body has a flat plate shape and a thin-walled cross-sectional shape, it can be easily attached and integrated along the peripheral surface of the cylindrical covering body, and the belt-shaped drain body can be mounted along the peripheral surface of the cylindrical covering body. Even if they are joined together, there is little or no narrowing of the right-angled cross-sectional area of the sand pile surrounded by the covering during the construction.Therefore, the loss cross-sectional area of the sand pile due to mounting the strip-shaped drain on the cylindrical covering is It is kept to a minimum, so there is no risk of the soft ground pressure being reduced by the constructed sand pile. Further, in view of the arrangement state of the band-shaped drain body, the band-shaped drain body functions by contacting a drainage region of a vast volume which is linearly or planarly spread.

By mounting the strip-shaped drain body along the peripheral surface of the cylindrical covering body, the filler has the function of pressing at least the soft ground in the horizontal direction and draining the water in the ground through the strip-shaped drain body. Therefore, it is possible to construct the sand pile without making the quality of the water permeability of the filling material a problem. For example, intermediate soil [soil having an intermediate particle size composition between sand and clay. "Geotech Note 2, Intermediate soil-sand or clay"
Soil material including cohesive soil, such as published by (Soil Engineering Society)
It is possible to use filling materials such as construction soil and coal ash.

When the strip-shaped drain body is mounted in the circumferential direction of the cylindrical covering body, the strip-shaped drain body mounted in the axial direction is cut due to an unexpected accident in the ground, and the continuous drainage of the strip-shaped drain body is cut off. Even when it is broken, the belt-shaped drain body is at least bridged to another belt-shaped drain body attached in the axial direction to ensure water permeability of the accident belt-shaped drain body through the horizontal belt-shaped drain body. When at least two strip-shaped drain bodies are diagonally crossed with respect to the longitudinal axis direction of the covering body, the intersecting portions have a function of ensuring continuity of water permeability.

[0021]

[Examples] Examples of the cylindrical drain structure and the soft ground improvement method according to the present invention will be described below with reference to the drawings. Since there are some that can be partially modified within the technical level, the constitutional requirements of the present invention are limited based on only the specific structures of the examples of the present invention without showing any special reason. Interpretation is not allowed.

(1) FIG. 1 is a perspective view of an essential part of an embodiment of the cylindrical drain structure of the present invention, in which the longitudinal direction (generic line) of the peripheral wall surface of the cylindrical cover 1 is shown. , A plurality of thin band-shaped drain bodies 2 are mounted in parallel. The cylindrical covering 1 is usually made of a flexible material such as a woven fabric, a knitted fabric, or a water-permeable thin non-woven fabric,
The cylindrical covering 1 has sand, gravel, pebbles,
It is strong enough not to be broken even if it is left in the soft ground in a state where it is packed with a filling material such as construction soil or industrial waste. The shape of the cylindrical cover 1 is a cylindrical body having the same diameter from end to end when no external force is applied, and normally both ends are open, but it may be bottomed (bag-like). However, it is necessary to leave an opening for efficiently charging and filling a filler such as sand, gravel, pebbles, construction soil or industrial waste in the inner side of the cylindrical covering 1.

The length of the cylindrical covering 1 in the longitudinal axis direction is substantially the same as the depth required for ground improvement. Generally, the water-permeable cylindrical coating 1 itself has a function of draining water in the ground, but this is not enough. As for the material of the narrow band-shaped drain body 2, two water-permeable material planes are arranged slightly apart from each other in parallel, and an intermediate material bent in a corrugation along the longitudinal axis direction is arranged therebetween, as if it were a corrugated cardboard-shaped structure. Forming the material, the band-shaped drain body 2
Has water permeability in the direction perpendicular to the plane and water permeability in the longitudinal direction. It is preferable that the thickness is about several mm and the width is about 5 to 20 cm. Due to its structure, it is difficult to bend in the longitudinal axis direction, and easy to bend in the perpendicular direction.

In this embodiment, a plurality of thin band-shaped narrow band drain bodies 2 are mounted on the outer peripheral wall surface of the cylindrical covering body 1 in parallel along the generatrix direction from end to end. The connection between the outer peripheral wall surface of the cylindrical covering body 1 and the band-shaped drain body 2 having a narrow ridge may be performed by crimping, nailing (for example, fixing with a stapler), bonding with an adhesive, or braiding. However, it is sufficient if it is not separated at least when constructing sand piles. Therefore, the connection structure of both materials can be selected according to the convenience of construction. The mounting ratio of the banded band-shaped drain body 2 to the outer peripheral surface of the cylindrical covering body 1 can be changed according to the degree of water permeability of the filler put into the cylindrical covering body 1.

For example, when the water permeability can be largely dependent on the sand pile itself, it is not necessary to increase the mounting ratio of the strip-shaped drain body 2 so much. That is, the squeezed water in the ground passes through the water-permeable cylindrical coating 1 and is collected by the water-permeable filler inside, and drained. However, when the filler to be put into the cylindrical covering body 1 is a clay filler (for example, intermediate soil), construction residual soil, etc. and water permeability cannot be expected so much, the mounting ratio of the belt-like drain body 2 is increased. At this time, the outer peripheral surface of the cylindrical cover 1 may have a function of connecting the side edges of the band-shaped drain body 2 having a narrow ridge.
In this case, the filler is expected to exert the action of pressing the soft ground in the horizontal direction to squeeze the water in the ground and collect the water in the strip-shaped drain body 2.

Further, since the strip-shaped drain body 2 is made of a thin material, when it is mounted on the cylindrical covering body 1, there is no risk of reducing the cross-sectional area of the sand pile to be constructed. That is, it becomes possible to depend more on the drainage effect of the strip-shaped drain body 2. At that time, if necessary, the band-shaped drain bodies 2 mounted on the outer peripheral surface of the cylindrical covering body 1 may be doubled or stacked.
When the constituent material of the cylindrical covering 1 has water permeability,
The strip-shaped drain body 2 can be attached to the inner peripheral wall of the cylindrical covering body 1. It can be said that the structure, the effect, and the construction method are almost the same as those in which the strip-shaped drain body 2 is attached to the outer peripheral wall of the cylindrical covering body 1. If the cylindrical coating 1 is a bottomed coating, the coating 1 is secured in the ground by the filling, and the cylindrical coating 1 does not move as the hollow tube is pulled out.

(2) FIG. 2 is a perspective view of a main part of another embodiment of the cylindrical drain structure and the soft ground improving method of the present invention, in which the longitudinal axis of the outer peripheral wall surface of the cylindrical cover 1 ( Bus)
A plurality of strip-shaped drain bodies 2 that are inclined with respect to the direction are arranged in a multiple spiral shape (however, the twist angle is small) in the longitudinal axis direction of the peripheral wall surface of the covering body 1. As described above, the material of the strip-shaped drain body 2 is hard to bend in the longitudinal direction, but it can be applied to the curved surface of the outer peripheral wall of the cylindrical covering 1.

The spirally wound band-shaped drain body 2 can be mounted on the outer peripheral wall of the cylindrical covering 1, respectively. For example, as shown in FIG.
When the left-handed spiral-wound strip-shaped drain body 2 is mounted on the inner peripheral wall, the strip-shaped drain bodies 2 mounted inside and outside the cylindrical covering body 1 cross each other, and the water passage surface is shown at the intersection (shown by a dotted line). 3 is formed (the cylindrical covering 1 is made of a water-permeable component). Therefore, even if one of the strip-shaped drain bodies 2 is damaged above the water-passing surface 3 for some reason and loses the drainage function to the ground surface, the strip-shaped drain body 2 on the other side is passed through the water-passing surface 3. The drainage action of the strip-shaped drain body 2 can be continued.

In the vertically long cylindrical covering 1, the water drainage surface 3 of each one strip-shaped drain body 2 mounted in a left-right spiral shape has a large number of water-passing surfaces 3, and thus the strip-shaped drain body is protected against external obstacles. It guarantees drainage of the body. Of course, this means that when all the spiral band-shaped drain bodies 2 are provided only on the outer peripheral wall of the cylindrical coating body 1, and when one of the belt-shaped drain bodies 2 is provided with the cylindrical coating body 1 as shown in FIG. The same applies when the other is arranged in a spiral shape in parallel with the generatrix direction.

(3) FIG. 4 is a measure against the case where a plurality of strip-shaped drain bodies 2 mounted on the peripheral wall surface of the cylindrical covering body 1 are mounted in parallel and do not have the water-passing surface 3 without crossing each other. , At least adjacent water-permeable strip-shaped drain bodies 2 are connected to each other, and the strip-shaped drain bodies 4 are arranged along the circumferential direction of the cylindrical covering body 1. Since both ends of the strip-shaped drain body 4 intersect and contact with each water-permeable strip-shaped drain body 2 to form a water-passing surface 3, one of the strip-shaped drain bodies 2 is damaged above the point and the ground surface is damaged. Even when the drainage function up to is lost, the drainage action to the surface of the belt-shaped drain body 2 can be continued through the other belt-shaped drain body 2. The band-shaped drain body 4
Is attached to the peripheral wall of the cylindrical cover 1 in an annular shape, so that the drainage function is further insured. Further, the shape retaining effect of the cylindrical covering 1 is also enhanced.

[0031]

As described above, the tubular drain structure of the present invention has an effective drainage effect without reducing the construction cross-sectional area of sand piles, while the drainage effect is separately provided by the belt-shaped drain body. In addition, it is possible to increase the shape retention of the cylindrical covering and efficiently insert the filling material during the construction, and adopt a structure that does not twist or damage the cylindrical covering. are doing.

Since the cylindrical drain structure of the present invention ensures the drainage function by the artificial drain, the filling material packed in the cylindrical covering body is compacted in the horizontal direction and is contained in the ground. It suffices to collect water in a band-shaped drain body of sand piles and drain it to the ground.
Not only sea sand but also mountain sand with a slightly inferior water permeability function, as well as powder material, soil material containing cohesive soil such as intermediate soil, construction waste soil, or packing such as industrial waste such as coal ash is used. can do. And so on, such a conventionally known net sand pile construction bag, etc., has a special action that cannot be expected,
It is possible to exert an effect.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a cylindrical drain structure of the present invention.

FIG. 2 is a perspective view of another embodiment of the cylindrical drain structure of the present invention.

FIG. 3 is a perspective view of another embodiment of the cylindrical drain structure of the present invention.

FIG. 4 is a perspective view of another embodiment of the cylindrical drain structure of the present invention.

[Explanation of symbols]

1 Cylindrical or bag-shaped cover made of knitted, woven or water-permeable plate material 2 Water-permeable belt-shaped drain material 3 Water-permeable surface 4 Horizontal belt-shaped drain material

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[Procedure amendment]

[Submission date] March 30, 1995

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

FIG.

[Fig. 2]

[Figure 3]

[Figure 4]

Front Page Continuation (72) Inventor Norihiro Tanimoto 1-18-2-502 Higashi Nakashin, Hirakata City, Osaka Prefecture (72) Inventor Kiyoo Nakayama 47-11 Tsuchimuro-cho, Takatsuki City, Osaka Prefecture (72) Makoto Otsuka Gifu Prefecture 416-57 Yoshida, Minami-cho, Kaizu-gun (72) Inventor Tadayoshi Maeda 2-40-1-806 Kitahonmachi, Funabashi, Chiba Prefecture

Claims (10)

[Claims] 1. One or a plurality of strip-shaped drain bodies are arranged on the inner or outer wall of a tubular or bag-shaped covering formed by a sheet-like material using a braided, woven or water-permeable material. A cylindrical drain structure that is installed. 2. The one or more strip-shaped drain bodies provided on the inner or outer wall of the tubular or bag-shaped covering body are arranged continuously in the vertical direction or the diagonal direction, respectively. The cylindrical drain structure described. 3. The one or more strip-shaped drain bodies provided on the inner or outer wall of the tubular or bag-shaped covering body are arranged in combination in a vertical direction and an oblique direction, respectively. Cylindrical drain structure. 4. The one or more strip-shaped drain bodies provided on the inner or outer wall of the tubular or bag-shaped covering body are arranged so as to cross each other diagonally. Cylindrical drain structure. 5. One or a plurality of strip-shaped drain bodies provided on the inner or outer wall of the tubular or bag-shaped covering body are continuously arranged in a vertical direction or an oblique direction, and at least adjacent strip-shaped drain bodies are connected to each other. The tubular drain structure according to claim 1, wherein the cylindrical drain structure is arranged so as to be connected in a horizontal direction. 6. The tubular drain structure according to claim 5, wherein the horizontal band-shaped drain bodies are arranged in a continuous annular shape. 7. The tubular drain structure according to claim 1, wherein the band-shaped drain has a thickness of several mm and a width of 5 to 20 cm. 8. The tubular drain structure according to any one of claims 1 to 7 is inserted into a hollow pipe penetrating into the ground, and sand or sand-like sand is inserted into the tubular drain structure. A method for improving soft ground, characterized in that a pile surrounded by a drain structure is formed in the ground by filling a powdery material and extracting the hollow tube. 9. The tubular drain structure according to any one of claims 1 to 7 is inserted into a hollow pipe that penetrates into the ground, and an intermediate soil or the like is inserted into the tubular drain structure. A method for improving soft ground, characterized in that a pile surrounded by a drain structure is formed in the ground by filling a soil material containing a cohesive soil and extracting the hollow tube. 10. The tubular drain structure according to any one of claims 1 to 7 is inserted into a hollow pipe penetrating into the ground, and construction residual soil or coal is inserted into the tubular drain structure. A method for improving soft ground, which comprises filling industrial waste such as ash and extracting the hollow tube to form a pile surrounded by a drain structure in the ground.