JPS644932Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention can be applied to golf courses, amusement parks, sports fields, tennis courts, pavements, factory green spaces, etc. by directing rainfall into the ground without changing the ground surface environment. This relates to a structure that temporarily retains surface flowing water within the ground, which is designed to temporarily retain water in the ground, alleviate rapid river rises, and prevent flood damage.

(Prior art) The inventor filed the application for utility model registration in 1981.
In No. 36834, diameter 2 to 50 with water absorption performance
Under the ground surface, a water retention body is formed by covering at least the upper surface of a group of grains with a uniform diameter of mm with a perforated sheet made of an incorrosive material that allows water to pass through but inhibits sand and mud from permeating, or a fiber sheet. We propose a structure that retains surface flowing water in the ground by burying it in the ground and installing a water guide part to the upper surface of the retention water body between the ground surface and the upper surface of the retention water body. The aim was to prevent flood damage in river basins where rivers are at risk of flooding due to rainwater, and to reduce the amount of rainwater runoff.

(Problem to be solved by the invention) However, in the above-mentioned structure for retaining surface flowing water in the ground, fine mud accumulates inside the sheets and grain aggregates over many years, and the initial water retention capacity is reduced. is decreasing.

(Means for solving the problem) The present invention was proposed to solve the above problem.
A water retention body is buried under the ground surface by covering the upper surface of a collection of grains of equal diameter with a perforated sheet or fiber sheet made of an incorrosive material that allows water to pass through but inhibits sand and mud from permeating. However, water partially passes through the inner wall surface that surrounds the outer periphery of the water body and is in contact with the water body.
This invention relates to a structure for retaining surface flowing rainwater in the ground, which is characterized by having a mud pit made of a perforated sheet or a fiber sheet that inhibits the permeation of sand and mud.

(Function) and (Effects of the invention) In the present invention, a mud pit is provided that surrounds the outer periphery of a water retention body buried under the ground surface, and the inner peripheral surface of the pit in contact with the water retention body is partially covered. Since the sheet is made of a perforated sheet or a fiber sheet that allows water to pass through but blocks sand and mud from permeating, the inside of the granule aggregates and the upper sheet may become clogged with ultra-fine mud over many years. Also, water is supplied and retained from the mud pit to the same grain aggregate group.

In addition, the sand and mud that entered the mud pit along with the rainwater, as well as the fine mud and extremely fine mud that are part of the sand and mud, settle and stay at the bottom of the pit, and this stagnant material is removed at certain intervals. Therefore, the original water retention capacity can be maintained without replacing the granule aggregation group.

(Example) The present invention will be described below with reference to the illustrated embodiments.

Artificial lightweight aggregates such as biltong (product name: manufactured by Sumitomo Mining Co., Ltd.) that have water absorption properties and a particle size of 2 to 50 mm, various rounded lapilli, perlite, anti-volcanic, tuff, porous Packing granules such as sintered materials into containers or bags made of perforated sheets or fiber sheets made of incorrosive rock wool, glass wool, carbon wool, polypropylene, etc., which allow water to pass through but sand and mud hardly pass through. The water retention body block 1 is buried in layers under the ground surface or under the paved surface of the ground, and an incorrosive perforated sheet or fiber sheet 2 that allows water to pass through but hardly permeates mud and sand is placed on top of the block. Bury it. The sheet 2 will cover the soil necessary for grass and trees, and the topsoil layer 3 will be used as is for an amusement park, tennis court, or green space within the factory.

A mud pit 4 in the form of an annular or polygonal frame is disposed surrounding the outer periphery of the first group of water retention blocks, and the inner wall surface of the pit 4 in contact with the outer circumferential surface of the first group of water retention blocks is partially , a perforated sheet or fiber sheet 5 made of an incorrosive material that allows water to pass through but prevents sand and mud from passing through. Reference numeral 6 in the figure indicates a water collection hole portion of the pit 4.

Since the illustrated embodiment is configured as described above, rainwater flowing on the ground surface passes through the perforated sheet or fiber sheet 2 and is guided to the water-absorbing granules in the water retention block 1. 60~ of ground volume
Approximately 80% of the water is temporarily retained without changing the ground surface environment, mitigating the sudden rise in river water levels.
Flood damage is prevented.

At this time, clogging due to fine mud is prevented by the perforated sheet or fiber sheet 2 and the perforated sheet or fiber sheet of the water retention body block 1 surrounding the granules.

However, over many years, fine mud accumulates inside the particles of the water retention body block 1, and the initial water retention capacity decreases. It is supplied to the grains of the water retention body block 1 through the perforated sheet or fiber sheet 5, thereby preventing a decrease in water retention capacity.

Furthermore, by removing the fine mud that remains at the bottom of the pit 4 at certain intervals, the original water retention capacity can be maintained without replacing the water retention body block 1.

Note that 7 in the figure is a discharge port for discharging the accumulated water in the pit 4 to the surrounding ground.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of a structure for retaining surface flowing rainwater in the ground according to the present invention. 1... Water retention body block, 2... Perforated sheet or fiber sheet, 4... Mud collecting pit, 5... Perforated sheet or fiber sheet.

Claims (1)

[Scope of utility model registration request] The upper surface of a collection of grains with a uniform diameter of 2 to 50 mm that has water absorption ability is covered with a perforated sheet or fiber sheet made of an incorrosive material that allows water to pass through but inhibits sand and mud from passing through. The water retention body is buried under the ground surface, and the inner wall surface in contact with the water retention body is made of a perforated sheet or fiber sheet that partially allows water to permeate but prevents sand and mud from permeating. A structure for retaining surface-flowing rainwater in the ground, characterized by having a mud pit arranged in the structure.