JPH1037172A - Water pass cylinder for preventing ground liquefaction and burying method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent liquefaction by providing a water pass cylinder which has many water inlets and a water pass passage in the direction of a ground surface and covers its outer periphery with water permeation sheet in a rear part of a tip cone. SOLUTION: A permeation water pass cylinder with tip cone 1 consists of a tip cone 2, a water pass cylinder 3, and a water permeation sheet 8, and many water inlets 5 and a water pass passage 6 are provided in the water pass cylinder 3. Next, an outer side of the sheet 8 is covered with a protective cylinder and advances into the ground down to predetermined depth, and then the protective cylinder is pulled out on the ground by preventing the rise of the permeation water pass cylinder 1 by earth and sand which enter in a recessed part 23. A rear end of the water pass passage 6 is opened on the ground surface, and its cross sectional area is large to such extent that capillary phenomenon does not occur. Underground water is not pumped up except when an earthquake occurs, and the water pass passage 6 is large to such extent that sufficient amount of water can escape on the ground surface when pressure of underground water is increased due to the earthquake. Since the sheet 8 passes only water and does not allow earth and sand to enter into the water pass cylinder 3 even when the earthquake occurs, the water pass passage 6 is not clogged and discharges clearance water on the ground before the ground is liquefied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water pipe to be buried in a liquefiable ground to prevent liquefaction of the ground during an earthquake and a method of burying the water pipe. It is buried in the ground that is easily liquefied at the time of grounding, perpendicular or oblique to the ground surface, and does not normally pump up groundwater.However, when groundwater pressure rises due to excessive pore water generated by vibration during an earthquake, The present invention relates to a water pipe having a water channel that can rise above the ground surface and a method of burying the water pipe.

[0002]

2. Description of the Related Art A water pipe to be buried in the ground which is easily liquefied during an earthquake and a method of burying the water pipe are disclosed in
No. 127823, JP-A-61-83711,
JP-A-63-89716, JP-A-2-18300
No. 6, JP-A-4-24330, JP-B-7-2
It is well known as seen in, for example, JP-A-6387, and a part thereof is implemented in various places.

[0003] However, in the conventional one using a crushed stone drain column or a water pipe, sediment is clogged between the stones of the crushed stone drain and the water passage during a long period until an earthquake occurs due to the constant pumping of groundwater by capillary action. However, in the case of an earthquake, it was often impossible to drain enough water. Therefore, it was necessary to regularly dig out the stones, remove and refill the sediment accumulated between the stones, and clean the water passages.If an earthquake occurred just before the maintenance, clogging would occur. The drainage speed of groundwater was slow, and sufficient liquefaction could not be prevented.

[0004]

Therefore, according to the present invention, construction work for installation is simple, there is no need for maintenance due to clogging with earth and sand during normal times, and a large amount of groundwater can be quickly drained to the ground during an earthquake, and liquefaction of ground The problem to be solved is to develop a water flow pipe for preventing liquefaction of the ground and a method of burying the water pipe without damaging the water pipe so as to surely prevent the liquefaction of the ground.

[0005]

According to the present invention, in order to solve the above-mentioned problems, a ground is buried in the ground and serves as a passage for releasing groundwater to the ground before the ground liquefies in the event of an earthquake. There is a tip cone formed of a hard material such as steel or plastic, and a number of water inlets are provided behind the cone, and a ground passage is formed in the surface direction in communication with the water inlet. A water-cylinder having a rigidity such that it is not crushed in the water, the water passage having a cross-sectional area large enough not to cause a capillary phenomenon, and a water-permeable sheet covering the outer periphery of the cylinder And a penetrating water-permeable cylinder provided with a tip cone, wherein the tip cone has a columnar portion protruding outside of the water-permeable sheet, and the soil and sand in the ground enter the portion. 1 recess, sun Chi, separate recesses, only horizontal transverse groove, has developed a vertical and horizontal directions of transmission through water bottle tipped cone for preventing soil liquefaction grooves are formed.

Further, according to the present invention, at least a part of the water-permeable sheet with a cone at the tip for preventing liquefaction of the ground is penetrated into the ground with the outer side of the water-permeable sheet being covered with a protective cylinder. Separating the protection cylinder from the permeation water cylinder with the tip cone, pulling out only the protection cylinder to the ground, and embedding the permeation water cylinder with the tip cone such that the permeation water cylinder with the tip cone is embedded at a predetermined depth in the ground Method developed.

[0007] In the present invention, the ground surface is
In addition to the general ground surface, it is used as a term that includes artificially formed cliffs, walls of tunnels and underground spaces, and the like. Further, the water-permeable sheet is made of a net, a woven fabric, a knitted fabric, or a non-woven fabric made of fiber, metal, plastic, chemical fiber, or the like, and is used as a term meaning a material having an excessive action.

[0008]

FIG. 1 is a block diagram showing an embodiment of the present invention.
6 through FIG. FIGS. 1 to 3 show a permeated water cylinder 1 with a tip cone according to the first and second aspects of the present invention.
FIG. 1 is a longitudinal sectional view including a center line of a permeated water-cylinder 1 having a tip cone, and FIG.
Fig. 3 shows the appearance of the tip cone and a cross-section of a state in which the permeated water passage portion and the outside thereof are covered with a protection tube 25.
FIG. 3 is a sectional view taken along line III-III in FIG. 1.

In FIGS. 1 to 3, reference numeral 1 denotes a permeate water passage with a tip cone, and reference numeral 2 denotes a tip cone. This tip cone 2 is made of a rigid material such as metal, plastic or even ceramics, the shape of which is, as can be seen particularly in FIG. 2, a cone 21 such as a pointed cone or pyramid followed by a cylinder or There is a pillar portion 22 such as a polygonal pillar. A recess 23 is formed on at least the outer surface of the pillar portion 22. This recess 23 may also be in the cone 21. Further, the conical portion 21 is not necessarily required depending on the soil quality, and may be only the column portion 22.
The tip may protrude into a hemisphere. FIG. 2
1 shows a state in which the permeation water cylinder portion of the permeation water cylinder 1 with the cone at the tip of FIG.

[0010] Behind the tip cone, there is a permeate water passage portion, which is composed of a water passage tube 3 and a permeate sheet 8 so as to cover the outer periphery thereof. The water passage tube 3 has an outer tube 4 and an inner tube 7 in which a number of water inlets 5 are formed, and a water passage 6 is formed between the outer tube 4 and the inner tube 7. The water pipe 3 is made of hard plastic, metal or inorganic material,
A large number of water inlets 5 communicate with a water passage 6, which extends in the axial direction of the water passage tube 3 over the entire length thereof, and has a rear end (right side in FIG. 1), that is, when it is buried. It is open where it touches the ground surface.

In a part of the water passage 6 between the outer cylinder 4 and the inner cylinder 7 of the water cylinder 3, a plurality of reinforcing members 9 extending in the axial direction at appropriate intervals as shown in FIG. There is a tubular body having such a rigidity that it is not crushed in the ground. And this water passage cylinder 3 and the permeable sheet 8
The operation rod 10 is connected to the distal end cone 2, and the operation rod 10 is inserted into a central hollow portion thereof. However, the connection of the water passage cylinder 3 and the water permeable sheet 8 to the tip cone 2 may be either one.

FIGS. 4 to 6 show a second embodiment of the permeate water cylinder 1 with a tip cone according to the first and second aspects of the present invention. FIG. FIG. 5 is a vertical sectional view including a line, FIG. 5 is a view showing the appearance of the tip cone 12, and a cross section of the permeated water passage portion and the outside thereof covered with a protection tube 25. FIG.
It is sectional drawing in the VI line.

In FIGS. 4 to 6, reference numeral 11 denotes a permeate water passage with a tip cone, and reference numeral 12 denotes a tip cone. The tip cone 12 is made of a rigid material such as metal, plastic or even ceramics, the shape of which is, as can be seen particularly in FIG. 5, a cone 21 such as a pointed cone or pyramid followed by a cylinder or There is a pillar portion 22 such as a polygonal pillar. A groove 33 is formed at least on the outer surface of the column portion 22. This groove 33 is a cone 21
There may be.

The conical portion 21 is not necessarily required depending on the soil quality, and may be only the column portion 22. The column portion 22 may have a tip end projecting into a semicircle. Tip cone 1
2, there is a permeate water cylinder part, which is
3 and a water permeable sheet 18 covering the outer periphery thereof. FIG. 5 is a perspective view of the permeated water cylinder 11 with a cone at the tip of FIG.
2 shows a state in which the permeate water-cylinder portion is covered with a protective cylinder 25.

The water passage cylinder 13 is formed by winding a large number of plastic linear objects in a meandering manner so as to be entangled with each other. The outer surface of the water passage cylinder 13 has a large number of openings, which serve as water inlets 15. A water passage 16 that extends in the axial direction is formed at a portion where the plastic linear objects are entangled with each other. Further, the hollow portion inside the portion where the plastic linear objects are entangled with each other also serves as the water passage 16.

These water passages 16 are open at the rear end (right side in the figure), that is, where they come into contact with the ground surface 40 when they are buried. Furthermore, these water passages 16 have a cross-sectional area large enough not to cause a capillary phenomenon, and no groundwater is pumped except during an earthquake. And when the underground water pressure increases due to the earthquake,
It is large enough to allow a sufficient amount of groundwater to escape to the surface.

It is natural that the water passage cylinder 13 also has such a rigidity as not to be crushed in the ground. The water passage cylinder 13 and the water permeable sheet 18 are connected to the tip cone 12
, And an operation rod 19 is provided at the center thereof. However, the tip cone 2 of the water passage cylinder 13 and the water permeable sheet 18
Connection to either of them.

The water passages 3, 1 used in these embodiments
At the outer periphery of 3, there are water permeable sheets 8, 18 which do not allow earth and sand having a particle size of several microns or more to pass through. I can't. Therefore, the water passages 6 and 16 are not clogged with earth and sand, and even during an earthquake, pore water generated by vibration can be quickly drained to the ground surface before the ground is liquefied, and the earth and sand are not spouted to the ground surface. Normally, the water-permeable sheets 8 and 1
Only water enters through 8, but this water does not rise above the level of groundwater, so that the surface of the ground will not be dampened with water.

Behind the tip cone 2, operation rods 10 and 19 penetrating through the center of the transmission cone 1 with the tip cone are inserted. It is used when entering the water pipe, when removing the protective cylinder, and also when performing maintenance. In particular, when adding multi-part water flow cylinders, they can be arranged straight, and meandering after embedding can be prevented.
However, the operation rod may not be provided.

Next, the third aspect of the present invention will be described. This permeated water cylinder with a tip cone is characterized in the part of the tip cone 51 as shown in FIG.
4 to 6, which are embodiments of the invention described in (1), a plurality of longitudinal grooves 54 in the axial direction are further provided. That is, in FIG. 9, the pillar portion 52 of the tip cone 51 has a horizontal transverse groove 52 and a vertical groove 54.
Are provided. Note that reference numeral 3 in FIG. 9 denotes a water passage cylinder having the same structure as that used in the previous embodiment.

Next, a permeated water cylinder with a tip cone according to a fourth aspect will be described. In the permeate water cylinder with the tip cone, the portion of the water cylinder 3, 13 in the embodiment of the invention described in claims 1, 2 and 3 is, for example, 120 cm.
It is divided into lengths and connected. This is used when it is difficult to handle the permeated water cylinder with the tip cone because of its long length or when the work site is narrow. Even when the permeated sheets 8 and 18 are appropriately divided into lengths, Good.

FIGS. 7 and 8 are views showing an embodiment of the invention described in claim 5, and are views showing a state in which the penetrating water-permeable cylinder 1 with a tip cone is advanced to a predetermined position on the ground. In these figures, reference numerals 1 and 11 denote permeation water passages with tip cones each including the tip cones 2 and 12 and the water passage cylinders 3 and 13 and the water permeable sheets 8 and 18. The outside of the sheets 8 and 18 is covered with a protective cylinder 25. This is to prevent damage to the permeated water-carrying cylinders 1 and 11 with the distal end cones. The distal end of the protective cylinder 25 is formed by screws formed on the rear ends of the distal end cones 2 and 12 or other unremovable engagement members. It is attached by the combining means, and in this state, it is weighted by its own weight or monken hammer, and is inserted into a hole 10 that has been dug in advance, or is advanced to a predetermined position on the ground while being excavated with a tip cone.

At this time, in order to prevent the protection cylinder 25 from being caught or dislodged from the ground, the pillar portions 22, 33, which are the maximum outer shapes of the tip cones 2, 12, are apparent from FIGS. 2, 5, and 7. In addition, it is larger than the outer diameter of the protection cylinder 25.

When it is difficult to handle the permeated water pipe 1 with a cone at the end thereof and the work site is narrow, only the water pipes 3 and 13 or the water permeable sheets 8 and 18 and the protective pipe 25 are appropriately long. Using the divided part, the part is made to enter the ground by the length of the divided part, and the parts are sequentially added to a predetermined length.

After the penetrating water-permeable cylinder 1 with the tip cone has been advanced to a predetermined depth, the protective cylinder 25 must be separated from the penetrating water-permeable cylinder 1 with the tip cone and pulled out to the ground. Therefore, it is necessary to reversely rotate the protection cylinder 25 or lift it upward to disengage the two, but the protection cylinder 25 and the permeate water-carrying cylinder 1 with the tip cone rotate together or move up. The recesses 23 and grooves 33 formed mainly in the column portions 22 and 32 of the tip cone 2 function to prevent the
It is. When the penetrating water-permeable cylinder 1 with the tip cone enters the ground, the surrounding earth and sand enters the concave portion 23 and the groove 33,
Prevents reverse rotation and elevation of the permeate water cylinder 1 with the cone at the tip. Thereby, the protection cylinder 25 is separated from the engagement portion of the tip cone 2,
Only the protection cylinder 25 can be extracted from the ground surface 40.

The concave portion 23 may have various shapes such as a circular shape, a triangular shape, and a rhombic shape, in addition to the rectangular shape shown, and the groove 33 may have a spiral shape. It is recommended to prevent reverse rotation or elevation of the permeate water-carrying cylinders 1 and 11 with the selected tip cone. Further, the protection cylinder 25 and the tip cone 2 are engaged with each other not only by screw connection, but also by a notch, a convex portion engaging with the notch, a bayonet-type engaging member, and other known detachable engaging means.

FIG. 8 shows a state in which the protection cylinder 25 has been removed from the state of FIG.
A flowing water layer 41 is continuously provided at an end facing the ground surface 40, and the flowing water layer 41 is connected to a drainage channel 42 such as a gutter, and is discharged through the permeated water flow cylinders 1 and 11 with a cone at the end of an earthquake during an earthquake. Underground water is discharged to rivers and sewers through these.

[0028] Such a permeated water-carrying cylinder 1 with a tip cone,
Numeral 11 denotes a plurality of holes that are buried regularly or randomly over a certain area. ▲ 砂 ▼
Only water is discharged from the water inlets 5 and 15 to the ground surface 40 through the water passages 6 and 16. For this reason, the pore water pressure of the groundwater decreases, and the sediment does not erupt along with the groundwater to the surface of the ground due to a crack having a low ground strength. Thereby, liquefaction of the ground at the time of an earthquake can be prevented.

[0029]

According to the first and second aspects of the present invention, the following effects can be obtained. 1. The liquefaction of the ground during an earthquake can be reliably prevented only by embedding a permeated water passage with a simple cone having a tip cone. 2. Maintenance is easy because no maintenance is required after burying the permeate water cylinder with the cone at the tip.

3. Since there is a concave portion or a groove on the surface of the tip cone, when the surrounding earth and sand enter therein and the protective cylinder is pulled out of the ground, the permeated water cylinder with the tip cone does not rise with it. 4. Since the cross-sectional area of the water passage of the permeate water cylinder with a tip cone is large, there is no rise in groundwater due to capillary action, and groundwater is not pumped up unnecessarily except during an earthquake, and it can drain groundwater in a short time during an earthquake. Liquefaction of the ground during an earthquake can be reliably prevented. 5. Because there is a water permeable sheet, sediment does not enter the water pipe and sediment is not discharged to the ground with groundwater. As a result, the ground does not collapse.

According to the third aspect of the present invention, the following effects can be obtained in addition to the above effects 1 to 5. 6. Because there are vertical grooves, it is easy to enter even on hard ground. 7, Since the part of the pillar part divided by the vertical and horizontal grooves is in the shape of a protrusion, depending on the geology, it engages with the surrounding soil and soil, and when the protective cylinder is pulled out from the ground, the permeated water cylinder with the tip cone is formed. Does not rise with it.

According to the fourth aspect of the present invention, the following effects can be obtained in addition to the effects 1 to 5 described above. 8. Since it is divided, it is easy to handle.
Easy to work in poor working environment. Further, according to the invention of claim 5, the following effects can be obtained. 9. Since there is a protection tube, the water passage tube, especially the water-permeable sheet, is not damaged when buried.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a permeated water cylinder with a tip cone according to the first and second aspects of the present invention.

FIG. 2 is a cross-sectional view of the appearance of the distal end cone of FIG. 1 and a cross section of a permeate water passage section, and a state where the outside of the permeate water passage section is covered with a protective cylinder. It is sectional drawing in the AA line in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a longitudinal sectional view showing a second embodiment of the permeated water cylinder with a tip cone according to the first and second aspects of the present invention. FIG. 4 is a sectional view taken along line BB in FIG. 3.

FIG. 5 is a cross-sectional view of the appearance of the distal end cone of FIG. 2 and a section of a permeate water passage section and a state in which the outside of the permeate water passage section is covered with a protective cylinder.

FIG. 6 is a sectional view taken along line VI-VI in FIG.

FIG. 7 shows a state in which a protective tube is placed over the permeated water tube with a cone at the tip of the present invention, and is penetrated into the ground.

FIG. 8 shows a state after the protective tube is removed from the state of FIG. 7,
In other words, this shows a state in which the permeated water pipe with the tip cone of the present invention is buried underground.

FIG. 9 shows the appearance of a tip cone of a permeation water cylinder with a tip cone according to the invention of claim 3, and a part of the permeation water cylinder.

[Explanation of symbols]

 1, 11: Permeate water passage cylinder with tip cone 2, 12, 50 ... Tip cone 3, 13 ... Water passage cylinder 4 ... Outer cylinder 7 ... Inner cylinder 5, 15 ... Water inlet 6, 16 ... water passage 8, 18, ... water permeable sheet 9 ... protection cylinder 10, 19 ... operation rod 21, 31, 51 ... cone part 22, 32, 52 ... pillar part 23, 33: recess 53: horizontal groove 54: vertical groove

Claims (5)

[Claims] 1. A tip cone which is buried in the ground and serves as a passage for allowing groundwater to escape to the ground before the ground liquefies in the event of an earthquake, and has a tip made of a hard material such as metal or plastic. There is provided a large number of water inlets at the rear of the cone, and a cylinder having such a rigidity that it is not crushed in the ground where a water passage is formed in the surface direction in communication with the water inlet. A water-permeable cylinder having a cross-sectional area large enough not to cause capillary action, and a water-permeable sheet with a tip cone provided with a water-permeable sheet covering the outer periphery of the cylinder. The tip cone has a columnar portion protruding outside of the water-permeable sheet, and a concave portion is formed in the portion to the extent that earth and sand in the ground are formed. Transmission through cone Water bottle 2. The permeate water cylinder with a tip cone for preventing ground liquefaction according to claim 1, wherein the recess formed in the tip cone according to claim 1 is one or more grooves in a substantially horizontal direction. 3. The tip cone according to claim 1, wherein the tip has a plurality of vertical grooves in the axial direction of the permeate water bottle with the tip cone, and one or more vertical grooves in a horizontal direction perpendicular to the vertical grooves. 2. A permeated water passage cylinder with a tip cone for preventing ground liquefaction according to claim 1, wherein said permeation passage has a lateral groove. 4. The permeate water cylinder with a tip cone for preventing liquefaction of the ground according to claim 1, wherein the permeate water cylinder with a tip cone is formed by connecting ones that are appropriately cut in length. 5. A passage that is buried in the ground and allows groundwater to escape to the ground before the ground is liquefied in the event of a haze, and the tip is formed of a hard material such as metal or plastic at the tip. There is a cone, and a large number of water inlets are provided behind the cone, and the rigidity is such that it is not crushed in the ground where a water passage is formed in the surface direction in communication with the water inlet. A water-permeable cylinder having a tip end cone provided with a water-permeable cylinder having a cross-sectional area large enough not to cause a capillary phenomenon, and a water-permeable sheet covering the outer periphery of the cylinder; The tip cone has a columnar portion that protrudes outside the water-permeable sheet, and a concave portion is formed in the portion so that earth and sand in the ground are formed. Transmission through tip cone At least a water cylinder is penetrated into the ground with the outer side of the water-permeable sheet covered with a protective cylinder, and when a predetermined depth is reached, the protective cylinder is separated from the permeate water-permeable cylinder with the tip cone, and it is pulled out to the ground and a tip cone is attached. A method of burying a permeate water cylinder with a tip cone, wherein the permeate water cylinder is buried at a predetermined depth in the ground.