JPH0528235Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a sunken underground storage tank constructed using the open cut construction method or the well construction method.

``Conventional technology'' In recent years, many water tanks have been manufactured for firefighting purposes or as a countermeasure against large-scale earthquakes.These water tanks are made of cast-in-place concrete, which is poured on-site, and concrete segments that are manufactured in factories. It is broadly categorized into precast concrete that is assembled on site.

In addition, the above-mentioned water tanks are often sunk underground, and in that case, if they are made of cast-in-place concrete, the so-called open-cut construction method involves digging a hole in advance, building a formwork there, and pouring concrete. In the case of precast concrete, the open cut method or the so-called well method, in which a water tank is assembled above ground and the earth and sand below is excavated and drained, sinks into the ground. Adopted.

``Problem to be solved by the invention'' When manufacturing the above-mentioned sunken water tank made of cast-in-place concrete, there is a drawback that the form work becomes large and the construction becomes troublesome.

On the other hand, when manufacturing a precast concrete submerged water tank using the well construction method, compared to using the open cut construction method, there is no need to dig a hole for installing the water tank in advance, and no sheet pile construction is required. Although it has the advantage of being easy to construct and is suitable for urban areas, it has the disadvantage that the concrete segment is heavy, requires a corresponding transport vehicle and heavy equipment for assembly such as a crane, and requires a large work space and access road. There is.

Particularly recently, the installation locations of water tanks are often limited to small areas in urban areas, and the construction of sunken precast concrete water tanks is restricted due to the inability to secure a large work space or access road. There is.

This invention was developed in view of the above circumstances, and whether the open cut construction method or the well construction method is used, the construction is much simpler than when constructing a conventional storage tank.
The purpose of the present invention is to provide a sunken underground storage tank that does not require a large work space or access road at the site.

``Means for Solving the Problems'' The submerged underground storage tank according to the present invention is characterized by its side plates, in which the outer periphery of the side plate has a segment structure made up of a combination of a plurality of metal segments, and the inner periphery of the side plate Part of the building is made of cast-in-place concrete.

"Function" In the above-mentioned submerged underground storage tank, the outer metal segment functions as earth retaining and formwork, and the inner concrete has watertightness, anti-corrosion functions, and also functions as a counterweight.

Furthermore, since metal segments are much lighter than concrete segments, they can be assembled using light and heavy machinery and can be transported using relatively small transport vehicles.

“Embodiment” An embodiment of the present invention will be described below with reference to the drawings.

Figure 1 is a partially sectional side view of a submerged water tank to which the present invention is applied, and in the figure, reference numeral 1
2 is a bottom plate, 2 is a side plate fixed on the top of the bottom plate 1,
Reference numeral 3 denotes a top plate fixedly installed on the upper part of the side plate 2, and a space 4 for storing water inside the tank is formed by these. The bottom slab 1 and the top slab 3 are made by placing reinforcement at the site and then pouring concrete.

The side plate 2 has a double structure of an outer peripheral part 2a and an inner peripheral part 2b. The outer circumferential portion 2a is made by connecting a plurality of arc-shaped steel segments 5, which are standardized in advance and produced in a factory, to each other in the circumferential direction and the axial direction (vertical direction) on site. The inner circumferential portion 2b is made of reinforced concrete poured on-site, similar to the bottom plate 1 and top plate 3. Waterproof mortar 6 is applied to a predetermined thickness (approximately 10 mm) on the inner surface of the inner peripheral portion 2b, the bottom plate, and the top plate. Note that the inner circumferential surface of the tank may be coated with a resin if necessary.

Note that 10 indicates leveled concrete, 11 indicates split stone, and 12 indicates a manhole.

Next, a method of constructing the above-mentioned underground water tank will be explained. Construction methods can be divided into the following three types depending on the installation location and ground conditions.

Open cut method The open cut method is used when the work site is large and the ground is sufficiently hard.

In this case, digging a hole for installing the water tank in advance and securing the earth with sheet piles 21 are the same as in the past, but when making the side slabs 2, the steel segments 5 are used as the outer formwork. Moreover, since this formwork requires almost no support (shoring), the construction period can be significantly shortened compared to the construction of conventional underground storage tanks made of cast-in-place concrete.

Inverse winding method The reverse winding method is used when the installation location is narrow, such as in urban areas, and the ground is of good quality.

In the case of the reverse winding construction method, for example, the side slabs 2 are constructed from the top, contrary to normal construction, and are constructed in order from the bottom side while excavating earth and sand. In this case, the steel segments 5 are used to function as earth retaining. This allows construction to proceed smoothly.

Well construction method The well construction method is used when the installation location is narrow and the ground is soft.

In this case, the main part of the water tank is constructed above ground, and the earth and sand underground is excavated and removed as it is gradually sunk downward.In this case, too, the steel segment 5 can function as a formwork. can.

Note that the above segments are not limited to steel, and may be made of other metals. Furthermore, it goes without saying that the above-mentioned underground storage tank can also store liquids other than water.

"Effects of the invention" As explained above, according to the sunken storage tank according to the invention, the metal segments forming the outer periphery of the side slab can function as earth retaining or formwork, and the construction method is open-cut. Regardless of whether the construction method, reverse winding method or well construction method is adopted, the construction period and cost can be reduced.

Furthermore, since the metal segments of the side plates can function as formwork, it is possible to save labor in removing the formwork and the like.

Further, since the concrete forming the inner circumferential portion of the side slab has a liquid-tight function and a corrosion-proofing function, there is no problem with liquid storage and progress of corrosion of the metal segments can be prevented. In addition, since the concrete also functions as a counterweight, it is possible to prevent the underground storage tank from floating when the water in the tank decreases.

In addition, since metal segments are much lighter than concrete segments, they can be assembled using light and heavy equipment and can be transported using relatively small transport vehicles, so there is no problem even if the work space is relatively small or the delivery path is small. Excellent effects such as construction progress can be achieved.

[Brief explanation of the drawing]

The drawing is a partially sectional side view showing an embodiment of the present invention. 1... Floor slab, 2... Side slab, 2a... Outer periphery of side slab, 2b... Inner periphery of side slab, 3... Top slab, 4...
Space, 5...Steel (metal) segment.

Claims (1)

[Scope of utility model registration request] In a submerged underground storage tank in which a space for storing liquid is formed inside by a bottom plate, a side plate, and a top plate, the outer periphery of the side plate has a segment structure consisting of a combination of a plurality of metal segments. This is a submerged underground storage tank characterized by the fact that the inner periphery is made of concrete that is cast on-site.