JPH10183593A - Pipe head cap for drain pipe method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe head cap which prevents breakage in the head part of a drain pipe and reduce the construction time and cost. SOLUTION: A head cap 40 is provided with an internal engagement part 40a which is internally engaged with a head opening part of a drain pipe 36a, a lid part 40b which is integrally formed in the internal engagement part and covers the head opening part, drain holes 40c which are formed in the lid part as a lot of small-diameter holes and communicate the inside with the outside of the drain pipe, and a seal material 40c which is stuck on the top face of the lid part and closes the drain hole. When this pipe head cap 40 is used, the water content generated in a drain layer is lead from the drain holes in the lid part into the inside of the drain pipe so that the drain pipe can be driven in a sandy ground till the same depth as the bottom face of the excavated ground to be excavated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe head cap mounted on a drain pipe head in a drain pipe method.

[0002]

2. Description of the Related Art When constructing a structure on a sandy ground, when the sandy ground liquefies, the structure is destroyed, falls, unequal settlement,
In order to cause damage such as levitation, multiple drain pipes are installed on sandy ground as a liquefaction prevention method, thereby shortening the horizontal drainage path and reducing the escape of excess pore water pressure generated during an earthquake. A drainage layer is provided between the sandy ground and the structure foundation by laying a gravel (crushed stone) mat on the excavated ground excavating the sandy ground to a predetermined depth from the top of each drain pipe. It communicates with the bed to secure a water pressure dissipation path.

FIG. 4 shows the head of the drain pipe 2. The drain pipe 2 is a pipe material whose head and lower end are opened, and a number of peripheral drain holes are formed in the peripheral surface thereof, and the peripheral pipe of the drain pipe 2 is prevented from being clogged with the peripheral drain holes. For this purpose, a filter material 3 is provided. A pipe cap 4 is attached to the head of the drain pipe 2.

[0004] The pipe cap 4 has a cylindrical outer fitting portion 4 a which fits externally to the head 2 a of the drain pipe 2, and is formed integrally with the outer fitting 4 a to form a head opening 2 a of the drain pipe 2.
and a lid 4b for closing the drain pipe 2 and has a function of protecting the head 2a when the drain pipe 2 is driven and preventing sand or gravel from entering the inside of the drain pipe 2.

When the pipe cap 4 having the above structure is attached to the head 2a of the drain pipe 2, the outer fitting portion 4a of the pipe cap 4 closes the drain hole on the upper surface of the drain pipe 2. A predetermined depth is set so that the pipe cap 4 of the pipe 2 is located at about several tens of centimeters in the drainage layer (that is, the pipe cap 4 of the drain pipe 2 is located at about several tens centimeters above the bottom of the excavated ground). It must be buried in sandy ground.

However, when each drain pipe 2 is buried in sandy ground so that the pipe cap 4 is located in the drainage layer, when excavating the ground, the excavating machine is operated by the head of the pipe cap 4 or the drain pipe 2. 2a may be damaged by contact.

Therefore, in order to prevent the excavating machine from coming into contact with the drain pipe 2 and the pipe cap 4, the drain pipe 2 has been cast on the sandy ground 6 to the same depth S ₁ as the bottom of the excavated ground until now. ; then (see Fig. 5), the depth pipe cap 4 is exposed from the drilling bottom 8a to S ₁ drilled drilling ground 8 (see FIG. 6), then remove the pipe cap 4, the drain pipe 2 head Then, a short drain pipe 2 'is connected by a join pipe 10, a pipe cap 4 is attached to the head thereof, and a gravel 12 is laid in the excavated ground 4 (see FIG. 7). The drain pipe 2 ′ is a pipe material having a large number of drain holes (not shown) formed on the peripheral surface.

When the construction method shown in FIGS. 5 to 7 is performed,
Since the Da設the drain pipe 2 to the bottom surface of the same depth S ₁ of the drilling ground, drain pipes 2 and pipe caps 4 by contact with the drilling machine there is no risk of damaging.

[0009]

However, the above-mentioned construction method has a problem in terms of construction cost because an extra drain pipe 2 'is required as shown in FIG.

In addition, before the gravel 12 is laid, the work of connecting the drain pipes 2 and 2 'by the joint pipe 10 must be performed, and there is a problem that much labor and time are required for the construction.

The present invention has been made in view of the above circumstances, and it is possible to prevent a drain pipe and a pipe cap from being damaged by an excavating machine, shorten a construction period, and reduce labor and construction costs. An object of the present invention is to provide a pipe head cap of a construction method.

[0012]

According to a first aspect of the present invention, there is provided a pipe head cap for a drain pipe method, wherein a gravel mat is laid in an excavated ground formed by excavating a sandy ground. Forming a drainage layer between the structure and the sandy ground, and connecting the upper part of the drain pipe cast in the sandy ground to the drainage layer to secure a path for dissipating the water pressure of the drainage layer. A pipe head cap to be attached to the head of the drain pipe, wherein an inner fitting part which is internally fitted into a head opening of the drain pipe; and the head opening part which is formed integrally with the inner fitting part. A cover, a drain formed in the cover as a large number of small-diameter holes and communicating between the inside and outside of the drain pipe, and a sealing material attached to an upper surface of the cover to close the drain. Equipped pipe head cap It is.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a structure 20 constructed on a sandy ground. A precast pile 24 is driven into a sandy ground 26 from a footing 22 of the structure 20.

An excavated ground 2 formed by excavating a sandy ground immediately below the structure 20 is provided on a foundation portion of the structure 20.
The drainage layers 32 and 34 are formed by laying a predetermined amount of gravel mats in the drainage layers 32 and 3.
4, the heads of drain pipes 36a to 36d and 38a to 38c, which are cast at predetermined intervals on the sandy ground 26, communicate with each other.

Here, the drain pipes 36a to 36d,
38a to 38c are cylindrical pipes whose upper and lower ends are open, and a large number of drain holes are formed on the peripheral surface. The outer circumference of the tube is surrounded by a filter material 39.

A pipe head cap 40 shown in FIGS. 2 and 3 is attached to the head opening. The pipe head cap 40 includes drain pipes 36a to 36a to 3d.
6d, inner fitting part 4 fitted inside head opening parts of 38a to 38c
0a, a lid 40b integrated with the inner fitting portion 40a to close the head opening, a number of small-diameter drain holes 40c formed in the lid 40b, and affixed to the upper surface of the lid 40b. And a sealing material 40d closing many drain holes 40c.

Next, a liquefaction prevention method in which the pipe head cap 40 is mounted on the drain pipes 36a to 36d and 38a to 38c will be described with reference to FIGS.

[0018] First, before forming the drilling ground 28, its bottom surface and the same depth S ₂ of the excavation soil 28 as the head is positioned, and Da設the drain pipe 36a~36d in sandy soil 26 To go. Before forming the excavated ground 30,
As the head is positioned at the bottom of the same depth S ₃ of the excavating ground 30, sandy soil 2 the drain pipe 38a~38c
I will cast it in 6.

Next, as shown in FIG. 1, excavation grounds 28 and 30 are formed by an excavation machine (not shown) so that the bottom surfaces have depths of S ₂ and S ₃ , respectively. As a result, as shown in FIG. 2, the pipe head cap 40 attached to the head openings of the drain pipes 36 a to 36 d is exposed on the bottom surface 28 a of the excavated ground 28.

Next, after removing all the sealing material 40d attached to the lid portion 40b of each pipe head cap 40, a predetermined amount of gravel (crushed stone) is laid in the excavation grounds 28 and 30, and the drainage layer 32 and 34 are provided.

When the above-described construction method is performed, the drainage layers 32, 3 formed by gravel are provided between the sandy ground 26 and the foundation of the structure 20.
Because of the provision of 4, the liquefaction can be prevented by shortening the horizontal drainage path and accelerating the escape of excess pore water pressure generated during an earthquake. Each of the drain pipes 36a to 36d and 38a to 38c has a large number of drain holes 40d formed in the lid 30b of the pipe head cap 40.
The drainage layers 32 and 34 are communicated with each other through the through holes, so that a sufficient water pressure dissipation path of the drainage layers 32 and 34 can be secured. Thus, liquefaction of the sandy ground can be prevented, and damage such as destruction, overturning, uneven settlement, and floating of the structure can be prevented beforehand.

Therefore, according to the present embodiment, the pipe head cap 40 is provided with the drain pipes 36a to 36a.
d, since the inner fitting portion 40a is fitted in the head opening portion of each of the head portions 38a to 38c in a state where the inner fitting portion 40a is fitted inside, there is no possibility that the pipe head cap 40 comes off when the casting is performed in the sandy ground 26.

The drain pipes 36a to 36d, 3
8a-38c, before forming excavated ground 28,32,
Since the head to the bottom of the same depth S ₂ thereof excavation soil 28, 32 are Da設in sandy soil 26 so as to be positioned, when forming the digging ground 28 and 32 by drilling machine, the drilling Damage to the head of the drain pipe and the pipe head cap 40 due to contact with the machine can be prevented.

In this embodiment, the excavated ground 28, 3
Since the sealing material 40d is stuck to the lid 40b of each pipe head cap 40 until immediately before the gravel (crushed stone) is laid in the inside of the pipe 0, the drain pipe 36a is inserted through the drain hole 40c.
To 36d and 38a to 38c can be prevented from entering.

Further, the drain pipes 2 and 2 'are connected to the joy pipe 10 as in the conventional method shown in FIGS.
The connection work becomes unnecessary, and the drain hole 30c can be easily opened simply by peeling off all the sealing material 40d stuck on the lid portion 40b of each pipe head cap 40, so that the process is immediately shifted to the next step. (That is, the excavated ground 28,
Since it is possible to immediately shift to the work of laying a predetermined amount of gravel (crushed stone) in the inside 30, the labor and the construction time can be greatly reduced, and the construction cost can be greatly reduced.

[0026]

As described above, according to the pipe head cap of the drain pipe method of the present invention, since the inner fitting portion is fitted inside the opening of the drain pipe head, the sandy ground There is no danger of the pipe head cap coming off during casting.

The drain holes formed as a large number of small-diameter holes in the lid can introduce moisture generated in the drain layer into the inside of the drain pipe, so that the water reaches the same depth as the bottom of the excavated ground to be excavated. It becomes possible to drive the drain pipe into the sandy ground. Thus, when the excavating machine forms the excavated ground, it is possible to prevent the head of the drain pipe and the pipe head cap from being damaged by the excavating machine.

Further, if a sealing material is stuck on the upper surface of the cover until immediately before the gravel mat is laid in the excavated ground, sand can be prevented from entering the drain pipe from the drain hole.

Further, it is not necessary to connect the drain pipe and the joint pipe as in the conventional method, and the drain hole can be easily opened only by peeling off all the sealing materials of the pipe head caps. As we can move immediately, we greatly reduce labor and construction time,
Construction costs can also be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a view showing a structure on a sandy ground to which a liquefaction prevention method according to the present invention has been applied.

FIG. 2 is a cross-sectional view showing a pipe head cap mounted on a head opening of a drain pipe according to the present invention.

FIG. 3 is a plan view showing a drain hole formed in a lid of a pipe head cap.

FIG. 4 is a cross-sectional view showing a state in which a conventional pipe head cap is attached to a head opening of a drain pipe.

FIG. 5 is a diagram showing a state in which a drain pipe is cast using a conventional pipe head cap.

FIG. 6 is a diagram showing a state where excavated ground is formed using a conventional pipe head cap.

FIG. 7 is a diagram showing a state in which a short drain pipe is connected to a rising portion of the drain pipe by a joint pipe so as to rise on the excavated ground.

[Explanation of symbols]

20 structure 26 sandy soil 36 a to 36 d, 38a-38c drain pipes 28 and 30 drilled ground 32,34 drainage layer S _2, S ₃ the depth of the bottom of the excavation soil 40 pipe head cap 40a in fitting portion 40b lid 40c Drainage hole 40d Sealing material

Claims (1)

[Claims] 1. A drain pipe formed by laying a gravel mat in an excavated ground formed by excavating a sandy ground to form a drainage layer between a structure and the sandy ground, and casting the drainage layer in the sandy ground. A pipe head cap attached to the head of the drain pipe when an upper part of the drain pipe is communicated with the drain layer to secure a path for dissipating water pressure in the drain layer. An inner fitting portion to be fitted,
A lid portion integrally formed with the inner fitting portion and covering the head opening portion, a drainage hole formed as a large number of small-diameter holes in the lid portion and communicating with the inside and outside of the drain pipe, and an upper surface of the lid portion. A pipe head cap of a drain pipe method, comprising: a sealing material that is attached and closes the drain hole.