JPH0618445U - Underground continuous wall with liquefaction control function - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a structure of a continuous underground wall having a liquefaction suppressing function and having excellent workability and economy. [Structure] A drainage member 1 made of grooved steel is integrally attached to the outer surface of a flange portion of an underground continuous steel material 5 having an H-shaped section by welding or the like. A large number of small holes 2 are formed in the drainage member 1, and a filter for blocking the intrusion of earth and sand is provided in the small holes 2 portion. The underground continuous wall 4 is formed by connecting a large number of steel materials 5 for underground underground walls by joints 6 at both ends of the flange portion in the wall continuous direction. When the excess pore water pressure of the ground around the underground continuous wall 4 rises due to an earthquake or the like, underground water is drained from the ground through the small holes 2 and the filter and through the inside of the drainage member 1. , Excessive pore water pressure of the surrounding ground is dissipated, and liquefaction of the surrounding ground is suppressed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 INDUSTRIAL APPLICABILITY The present invention is a liquid used for underground walls of buildings constructed on the ground where liquefaction may occur, underground continuous walls such as sewage treatment plants, underground spaces, bridge foundations, common ditches, and retaining walls such as underground tanks. It relates to a continuous underground wall with a deteriorating function.

[0002]

[Prior art]

 The current underground continuous wall construction method is as follows: after excavating the ground, insert reinforcements such as reinforcing bars, and place concrete in it.Place-in-place concrete underground continuous wall, stress material is inserted into the ground, and the surrounding area. Stable solidified underground continuous wall that solidifies the steel with solidifying material, steel underground underground wall where steel materials such as box sheet piles are driven into the ground, the inside or outside is excavated, and soil cement is injected to solidify, etc. There is.

On the other hand, as a countermeasure against liquefaction of the underground continuous wall constructed in the ground where there is a risk of liquefaction, there is a method of using a soil compaction method or a ground improvement method, and the rigidity of the underground continuous wall is There is a structure countermeasure that is designed to withstand the external force generated during liquefaction.

[0004]

[Problems to be solved by the device]

 As a countermeasure against the liquefaction of underground continuous walls, the ground compaction method is difficult in terms of cost when the liquefied layer and the soft ground are alternating. The ground improvement method is complicated in construction, and has problems in terms of construction period and cost. Also, when dealing with structures, the wall width becomes thicker because of the need for greater rigidity, which makes workability and cost difficult.

The present invention aims to solve the above-mentioned problems in the prior art, and has a structure of an underground continuous wall which has a liquefaction suppressing function of the underground continuous wall itself and is excellent in workability and economy. It is provided.

[0006]

[Means for Solving the Problems]

 The underground continuous wall with liquefaction prevention function of the present invention is an underground continuous wall constructed in the ground where liquefaction is likely to occur, and one or both sides of the underground continuous wall are integrated with a drainage member extending in the depth direction. It was installed in. The drainage member is used to dissipate excess pore water pressure generated in the ground during an earthquake, and a large number of holes are provided in the longitudinal section of the drainage member to prevent soil from entering the holes. Install a filter for

The structure of the underground continuous wall is not particularly limited, but in the case of a steel underground continuous wall, the drainage member is provided integrally with the steel material for the underground continuous wall forming the underground continuous wall such as a box sheet pile. It can be installed in the ground by casting it integrally with the steel material for underground wall. In the case of cast-in-place concrete underground continuous walls, etc., a drainage member that forms a closed cross section, such as a pipe, must be installed at the underground continuous wall position (one or both sides of the underground continuous wall) before excavation. It can also be integrated with the underground wall by placing concrete etc. into the grooving. In this case, it goes without saying that a hole for the drainage member for draining water due to the generation of excess pore water pressure is provided on the surface of the ground that is in contact with the soil.

[0008]

[Action]

 Water in the ground, which has been subjected to excessive pore water pressure generated during an earthquake, is drained through a large number of holes provided in the drainage member through the drainage member, which results in an excessive gap water pressure around the underground continuous wall. It disperses, and liquefaction around the continuous underground wall is suppressed. At this time, infiltration of earth and sand into the drainage material is blocked by the filter in the hole.

Due to the effect of suppressing the liquefaction of the surrounding ground by the drainage members provided on one side or both sides of the underground continuous wall, the ground resistance can be taken into consideration in the design of the underground continuous wall, and the economical design can be realized. And the safety in case of an earthquake will be greatly improved.

Further, since the drainage member provided on the underground continuous wall suppresses liquefaction, no special liquefaction countermeasure is required when constructing the underground continuous wall on the ground where there is a possibility of liquefaction. . This improves workability and shortens the construction period.

[0011]

【Example】

 Next, an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 and FIG. 2 show an embodiment of a continuous underground wall with a liquefaction suppressing function of the present invention.

In the present embodiment, a large number of steel members 5 for underground continuous walls each having an H-shaped cross section consisting of a web portion and a flange portion are connected in the wall continuous direction by joints 6 at both ends of the flange portion to form an underground continuous wall 4. Is forming. The drainage member 1 made of channel steel is integrally attached to the outer surface of the flange portion of the steel material 5 for continuous underground wall by welding or the like, and is constructed in the excavation groove together with the steel material 5 for underground continuous wall. Get caught.

As shown in FIG. 1 or FIG. 3, the drainage member 1 has a large number of small holes 2 formed therein. Although not shown, this small hole 2 portion is for preventing the intrusion of earth and sand. Is equipped with a filter. The filter may be directly attached to the small hole 2 portion, but may be of a type in which a plug with a filter is fitted into the small hole 2. In addition, in this embodiment, the shape of the tip of the drainage member 1 is sharpened for the purpose of suppressing the penetration resistance at the time of driving and press fitting, and the lid 8 is provided at the upper end to prevent the entry of earth and sand. It is preventing. A filter or the like may be attached to the upper end instead of providing the lid 8.

The cross-sectional shape of the drainage member 1 is not limited to the groove shape, and there is an angle steel or a semi-circular member that forms a drainage space of a closed cross section by being attached to the outer surface of the flange of the steel material 5 for underground underground wall. Alternatively, a member having a closed cross section such as a pipe may be used.

Further, the underground continuous wall 4 can be composed only of the steel material 5 for the underground continuous wall to which the drainage member 1 is attached, but as shown in FIG. It is also possible to fill concrete 7 or mortar etc. to improve the waterproofness and rigidity.

FIG. 4 is a conceptual view of the underground continuous wall with drainage function of the present invention. During an earthquake, water whose pressure has increased due to liquefaction of the ground 10 is drained from a hole through a filter as shown by an arrow. It flows into the drainage member 1, passes through the internal space of the drainage member 1, and is drained from the upper part of the drainage member 1 to the ground.

FIG. 5 shows another embodiment of the present invention. As the steel material 5 for underground wall, a steel material having a box-shaped cross section having joints 6 at both ends of the flange is used.

In addition to this, it is also conceivable that the body of the underground continuous wall is made of cast-in-place concrete or a precast concrete member, and a drainage member is provided on these.

[0020]

EFFECT OF THE INVENTION Since the underground continuous wall itself has a liquefaction suppressing function, liquefaction around the underground continuous wall is suppressed.

Due to the effect of suppressing the liquefaction of the surrounding ground, ground resistance can be taken into consideration in the design of the continuous underground wall, which leads to an economical design and greatly improves the safety during an earthquake.

When constructing a continuous underground wall in the ground where there is a risk of liquefaction, no special liquefaction measures are required, which improves workability and shortens the construction period.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a continuous underground wall with a liquefaction suppressing function of the present invention.

2 is a plan view of a steel material for underground continuous wall corresponding to the embodiment of FIG. 1. FIG.

FIG. 3 is a perspective view showing an example of the shape of a drainage member.

FIG. 4 is a vertical cross-sectional view for explaining the drainage function of the underground continuous wall with a liquefaction suppressing function of the present invention.

FIG. 5 is a plan view showing another example of steel material for an underground continuous wall.

[Explanation of symbols]

1 ... Drainage member, 2 ... Hole, 3 ... Drainage member tip part, 4 ...
Underground continuous wall, 5 ... Steel material for underground continuous wall, 6 ... Joint part, 7 ...
Concrete, 8 ... Lid, 10 ... Layer that may liquefy

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Kida 4-53-3 Kitahama, Chuo-ku, Osaka Sumitomo Metal Industries Co., Ltd.

Claims (2)

[Scope of utility model registration request] 1. A drainage member extending in the depth direction of the underground continuous wall is integrally provided on one or both sides of the underground continuous wall constructed in the ground where liquefaction is likely to occur. A continuous underground wall with a liquefaction inhibiting function, characterized in that a large number of holes are provided in a predetermined section in the longitudinal direction of the member, and a filter for preventing intrusion of earth and sand is provided in the holes. 2. The underground continuous wall with a liquefaction inhibiting function according to claim 1, wherein the drainage member is provided integrally with a steel material for an underground continuous wall which constitutes the underground continuous wall.