JPH0216219A - Laying work of underground structure - Google Patents

Abstract

PURPOSE:To meet the buoyancy of an underground structure by a method in which a foundation concrete is placed into a space for an underground structure, and the foundation concrete is connected with the underground structure set on the foundation concrete by wires. CONSTITUTION:A space 2 slightly larger than an underground structure 1 is formed in the space where the underground structure is to be set up, and reinforced foundation concrete 3 is placed on the bottom of the space. The underground structure 1 having a floor area smaller than the planar area of the concrete 3 is set up on the central part of the concrete 3 and connected by wires 7 and turnbuckle 8 placed between anchor bolts 5 and the upper hooks 6 of the structure 1. Soil and stones 9 are then placed on the concrete 3 along the periphery of the structure 1 inside the space 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a construction method for burying a closed underground structure such as a basement underground.

BACKGROUND OF THE INVENTION From the viewpoint of effective use of land, various underground structures such as basements have been developed and are being put into practical use. When these sealed underground structures are buried below the water level at the buried location, they tend to float up due to the influence of buoyancy. If the underground structure is installed under a house on the ground, the buoyant force can be offset by the gravity of the house. However, when there are no above-ground buildings at the location where the underground structure is buried, it is necessary to take measures against the buoyancy during the process of burying the underground structure.

Conventionally, underground structures of this type have been fixed to the foundation concrete using anchor bolts or the like at the lower portion. However, according to this construction method, the amount of foundation concrete poured increases, the foundation work becomes deeper, and as a result, the construction cost increases. In addition, underground structures are fixed to the foundation concrete with anchor bolts at the lower part, so once an underground structure is buried, it is difficult to release the anchor bolts unless all surrounding soil and stones are removed. This makes maintenance and inspections after construction complicated.

OBJECT OF THE INVENTION Accordingly, an object of the present invention is to simplify the construction of foundation concrete while making it possible to sufficiently cope with the buoyancy of underground structures. Another purpose is to connect the foundation concrete and underground structures near the ground level,
The aim is to facilitate maintenance and inspection after construction.

Solution to the Invention In view of the above-mentioned object, the present invention involves pouring a foundation concrete larger than the floor area of the underground structure into the bottom of the buried space of the underground structure, and forming a part of the foundation concrete larger than the floor area of the underground structure. It receives the weight of the earth and stones above, and uses this weight to offset the buoyancy of the underground structure on the foundation concrete.

Further, this underground structure is connected to the foundation concrete by an anchor bolt or the like of the foundation concrete at the upper part of the underground structure by a wire.

Therefore, they can be fixed in the upper part of the buried work, and even after being buried, maintenance and inspection of that part can be easily performed.

DETAILED DESCRIPTION OF THE INVENTION FIGS. 1 and 2 show a method for burying a closed underground structure 1 such as a basement according to the present invention.

A buried space 2, which is slightly larger than the underground structure 1, is formed at the buried position of the underground structure 1, and a reinforced concrete foundation 3 is poured into the bottom of the buried space 2. A plurality of anchor bolts 5 are embedded in this foundation concrete 3 along with an anchor beam 4.

Here, the floor area of underground structure I is the foundation concrete 3
is set smaller than the plane area of . The periphery of the inner wall of the buried space 2 is surrounded by arrows Fiio, and is held by support beams 11 so as not to collapse inward.

Then, on top of this foundation concrete 3, an underground structure 1 with a floor area smaller than the floor area of the foundation concrete 3 was placed, and a frame was passed between the anchor hole 5 and the hook 6 at the top of the underground structure 1. Connected by wire 7 and turnbuckle 8. Thereby, the underground structure 1 is fixed almost at the center on the foundation concrete 3.

After doing this, the earth and stone 9 are thrown into the bottom part of the burial space 2. As a result, the soil and stones 9 after being introduced are sequentially deposited on the foundation concrete 3 along the outer periphery of the underground structure 1 inside the burial space 2, and their gravity is applied to the upper surface of the foundation concrete 3. Of course, the sheet piles 10 and the support beams 11 are removed in advance in response to this loading of the upper part 9.

When the underground structure 1 is buried, a buoyant force F corresponding to the amount of drainage acts on the part of the underground structure 1 based on the water level at that location according to Archimedes' principle, so the underground structure 1 will float due to the buoyant force F. Trying to go up. However, this underground structure 1 is fixed to the foundation concrete 3, and on top of this foundation concrete 3, there are stones and earth 9! Since the amount Ml is acting, as shown in Fig. 3,
The buoyant force F is offset by the sum of the weight M2 of the foundation concrete 3 and the weight fM1 of the upper part 9 above the foundation concrete 3. Therefore, this underground structure 1 is stabilized in the buried state without receiving any special external force from above ground. Therefore, the sum of I(fM 2 of the foundation concrete 3 and the weight !1M1 of the earth and stone 9 on top of the concrete 3 is the buoyant force F
must be significantly larger than . If the inner wall of the burial space 2 is formed vertically at the initial stage of construction and the heavy IMI of the soil and stones 9 embedded therein is insufficient, the inner peripheral wall of the burial space 2 may be , as shown by the dotted lines in FIGS. 1 and 2, with a slope that widens upward. The inclination angle α at this time is set to an angle that maintains a stable state without collapsing, that is, an angle of repose, taking into account the properties of the soil and stone. When the soil and stones 9 are placed on the foundation concrete 3 in this state, the soil and stones 9 in the space from the slope line to the outer periphery of the underground structure 1 are
Since it acts as a weight M1 on the upper surface of the foundation concrete 3, the required weight IMI of the soil and stones 9 is increased overall.

Effects of the Invention In the present invention, since the weight of the soil and stone surrounding the underground structure acts on a portion of the foundation concrete that is larger than the floor area of the underground structure, the sum of the weight of the soil and stone and the weight of the foundation concrete causes a The buoyancy of fixed underground structures can be sufficiently offset. Therefore, it is easy to bury it underground in areas where the water level is relatively high. Therefore, it is possible to bury an underground structure even in a location where there is no building above the underground structure and whose weight cannot be used as a force to counteract buoyancy.

Since the underground structure is attached to the underground foundation concrete using wires at the upper part, connection operations can be performed at the upper part of the underground structure, that is, close to the ground level, and maintenance and inspection of the connection part is possible even after embedding work. It becomes easier.

[Brief explanation of the drawing]

FIGS. 1 and 2 are vertical cross-sectional views of the buried underground structure, and FIG. 3 is an explanatory diagram of the relationship between gravity and buoyancy. 1. Underground structure, 2. Buried space, 3. Foundation concrete, 7. Wire, 8. Turnbuckle, 9.
・Soil and stone.

Claims (1)

[Claims] A foundation concrete is poured into the bottom of the buried space of the underground structure, an underground structure with a floor area smaller than the floor area of the foundation concrete is placed on top of this foundation concrete, and the foundation concrete and the top of the underground structure are connected with a wire. Then, along the outer periphery of the underground structure in the buried space,
A method for burying underground structures characterized by placing soil and stones on top of the foundation concrete and using the weight of the soil and foundation concrete to offset the buoyant force acting on the underground structure.