JPH1037221A - Construction of facility embedding underground storage tank and its working method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a required bearing power without driving piles even to soft ground, to prevent cracking and to shorten the period of construction work. SOLUTION: Floor portion for an underground pit 13, on which a storage tank is to be installed, should be formed by laying foamed blocks 24 on a leveling layer 23 with unevenness corrected and pouring concrete over the blocks, thereby forming a paved floor surface lever 26. And the pavement near the blocked top surface of the underground pit 13 should be formed by laying formed blocks 24 over a leveling layer 41 with the irregularity corrected, laying a protection concrete layer 42 to the top surface of which an inorganic crystal- growing agent with water-soluble silicate and magnesium fluoride compound as principal components added, and then concrete is placed on the protection layer 42 for forming the surface paving layer 43.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a facility, such as a gas station, in which a storage tank is buried underground, and a method of constructing the facility.

[0002]

2. Description of the Related Art A typical example of a facility in which a storage tank is buried underground is a gas station. In a gas station, a tank for storing gasoline and kerosene is buried underground, and vehicles for refueling frequently come and go, so that the ground support is important. The bearing capacity of this ground varies greatly from region to region. For this reason, in the case of land with strong bearing capacity, a predetermined bearing capacity can be obtained by mixing a soil conditioner, but in the case of soft ground, as shown in the figure, the predetermined bearing capacity can be obtained. It is common practice to drive a large number of friction foundation piles 3... Not only under the floor of the pit 1 of the underground tank but also on the runway 2 in order to secure the ground.

[0003]

However, the operation of driving the friction foundation piles 3... Not only raises the problem of vibration and noise, but also increases the number of work steps, so that the construction period becomes longer and the cost increases. Would. In addition, friction foundation pile 3
Even if the supporting force is increased by driving…, as shown in the figure, the pile 3 can only support the surface pavement 4 at points, so the pavement 4 between the piles 3 should be uniformly supported. It is difficult. For this reason, when a heavy vehicle such as a large truck runs, the pavement 4 slightly undulates or sinks,
Repeating this causes cracks.

[0004] In addition, the concrete pavement surface may be repeatedly shrunk by cold and warm, and cracks may be generated. There is a problem that the concrete becomes brittle and the strength is reduced. Moreover, concrete shrinks little by little with the passage of time, and cracks due to this shrinkage also occur. Sometimes joints are cut to prevent these cracks,
Conventional joint cutting is insufficient and cracks cannot be reliably prevented. In practice, repairs such as filling the cracks with epoxy resin are frequently performed.
And the cost and labor required for this repair are also problems. Further, in a gas station, if spilled gasoline or the like enters the cracks, it is dangerous, and this is a problem from the viewpoint of protecting the natural environment.

Therefore, the present invention can obtain a predetermined supporting force without driving a pile even on soft ground,
An object of the present invention is to provide a structure of a facility in which a storage tank is buried underground and a construction method thereof, which can prevent cracks and shorten a construction period.

[0006]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above-mentioned object, and the structure according to claim 1 has a structure in which concrete is formed at least at the bottom of a hole which has been drained to a depth where a tank can be buried. Casting to form an underground pit,
A storage tank is installed in this underground pit, and the top opening of the underground pit is closed, and the underground pit is covered with concrete at the same height as the surrounding area. It is constructed by laying foam blocks on the leveling layer that has been adjusted and forming a floor pavement layer in which concrete is cast on these foam blocks, and the pavement around the closed upper surface of the underground pit,
A foam material block is laid on the uneven leveling layer, and a protective layer made by adding an inorganic crystal breeding material containing water-soluble silicate and a magnesium fluoride compound as a main component to concrete is provided on the upper surface of the foam material block. It is a structure of a facility in which a storage tank is buried underground, characterized in that it is formed by forming a surface pavement layer in which concrete is cast on the protective layer.

According to a second aspect of the present invention, in addition to the first aspect, the floor portion of the underground pit is provided with a foam material block laid on an uneven ground foundation layer, and an upper surface of the foam material block is provided. By forming a protective layer in which an inorganic crystal breeding material containing water-soluble silicate and magnesium fluoride compound as main components is added to concrete, and forming a floor pavement layer in which concrete is cast on the protective layer. It is a structure of a facility where a storage tank characterized by being constructed is buried underground.

According to a third aspect of the present invention, the foam block is a block made of expanded polystyrene.

According to a fourth aspect of the present invention, the foam material block is a foam concrete block.

[0010] In the construction method according to the fifth aspect, concrete is poured into at least the bottom of the hole that has been excavated to a depth where the tank can be buried to form an underground pit, and a storage tank is installed in the underground pit. In closing the opening of the upper surface of the underground pit and constructing a facility where the closed upper surface of the underground pit is paved with concrete at the same height as the surrounding area,
The floor portion of the underground pit has a leveling layer forming step of forming a leveling layer by irregularly adjusting the bottom of the hole, a foaming material block laying step of laying a foaming material block on the leveling layer, and a foaming material block laying step. Pavement around the closed top surface of the underground pit is leveled by unevenness to form a leveling layer, and foaming is performed on this leveling layer. Layer laying step of laying a material block, and a protective layer forming step of forming a protective layer on the upper surface of the foam material block by adding an inorganic crystal breeding material mainly composed of a water-soluble silicate and a magnesium fluoride compound to concrete And a concrete pouring step of pouring concrete on this protective layer. Facility is a construction method.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, a gas station will be described as an example of a typical facility in which a storage tank is buried underground.

As shown in the plan view of FIG. 1, the gas station 11 has a pit 13 formed underground for burying a storage tank 12 such as a gasoline storage tank or a kerosene storage tank underground. In addition, a fire wall 14 is provided on the boundary excluding the road side, an office building 15 is built on one side of the site, a canopy 16 is extended from the office building 15, and a lower part of the canopy 16 is A refueling machine will be installed in the plant and a suspended refueling machine will be installed. And
The upper surface opening portion of the underground pit 13 is closed, and the closed upper surface of the underground pit 13 is paved with concrete at the same height as the periphery of the underground pit 13 to form a vehicle traveling path 17. In addition,
In FIG. 1, reference numeral 20 denotes an automatic car wash, and 21 denotes a car wash.

In order to construct the underground pit 13, first, the soil is sufficiently discharged to a depth where the tank 12 can be buried (a discharging step). Then, crushed stones or the like are laid at the bottom of the hole and rolled to form a base layer 22 (base layer forming step), and sand or a loose lightweight aggregate is laid horizontally on the base layer 22, That is, leveling is performed to form the leveling layer 23 (leveling layer forming step). The leveling layer 23 is a layer for arranging the foam blocks 24 to be described later in a stable state so that they can be laid horizontally in a stable state, and for preventing the laid foam blocks 24 from becoming uneven. When the leveling layer 23 is formed, a foam material block 24 is laid on the leveling layer 23 (foam material block laying step).

The foam material block 24 functions as a ground stabilizing material. In this embodiment, the foam material block 24 is a block made of expanded polystyrene having a width of 2 m, a length of 1 m, and a thickness of 50 cm (styrene foam block 24). When the styrofoam block 24 is laid, the styrofoam block 24 is laid while being connected using a tie (not shown) so as not to be separated from an adjacent one. The binding metal has claws on both sides, and the nails are pierced into adjacent styrofoam blocks 24 to bind the two blocks together.

The styrofoam block 24 is lightweight,
Not only is it excellent in heat insulation and sound insulation, but it also has sufficient compressive strength. In the case of the gas station 11 as in the present embodiment, it is preferable to use a gas-resistant one. Further, since the polystyrene foam is melted by a solvent such as gasoline or kerosene, the protective layer 25 is formed on the upper surface (protective layer forming step).

The protective layer 25 is formed by applying a material obtained by adding an inorganic crystal growth material to concrete. This inorganic crystal breeding material contains a water-soluble silicate and a magnesium fluoride compound as main components. The function of the inorganic crystal breeder will be described later.

After the protective layer 25 is formed, the concrete is cast on the protective layer 25 to form the floor pavement layer 2.
6 is formed (concrete casting step). When the floor pavement layer 26 is formed, concrete is poured after the reinforcing bars 27 are arranged.

When the floor of the underground pit 13 is constructed in this way, the gantry 28 of each tank 12 is constructed of concrete or the like, and the side wall 29 of the underground pit 13 is constructed. The support wall 30 which also functions as a partition wall is constructed.

The side wall 29 is constructed by installing a concrete base block 31 having an L-shaped cross section on the floor pavement layer 26, and constructing a concrete wall on the base block 31. In this embodiment, when constructing a concrete wall, as shown in FIG. 7, a styrofoam mold 32 is assembled, and the molds 32 on both sides are fixed to each other by holding metal fittings 33 and the like. Reinforcing bar 3 inside
4 and the concrete is cast and integrated with the formwork 32 to build a wall.

As described above, when the styrofoam form 32 is used, it is not necessary to remove the form 32 after the concrete is cured, so that labor can be saved and the construction period can be shortened. In addition, the mold 32 made of Styrofoam has a large number of small concave portions due to foam on the contact surface with concrete, and therefore has a strong bonding force with cast concrete. As described above, the surface of the side wall 29 thus constructed, particularly the surface on the tank side,
It is desirable to form a protective layer by applying a material obtained by adding an inorganic crystal breeder to concrete. If a protective layer is formed on the surface of the side wall 29, it is possible to protect the styrofoam even if fats such as gasoline adhere. The fire wall 14 can be similarly constructed.

In this embodiment, the support wall 30 is constructed by stacking styrofoam blocks.
Then, it is desirable to form a protective layer on the surface of the styrofoam block by applying a material obtained by adding an inorganic crystal breeding material to concrete, similarly to the side wall 29. When a block made of Styrofoam is stacked, when cement milk is used as an adhesive, a strong bonding force can be obtained due to the presence of the small recesses of Styrofoam, as described above.

The side wall 29 and the support wall 30
May be constructed by stacking concrete blocks, or constructing a metal or wooden formwork, casting concrete, and removing the formwork after curing. Also,
The formwork 32 may be made of foamed concrete, which has better fire resistance.

After the underground pit 13 is constructed in this manner, the storage tank 12 is installed and fixed on the gantry 28, and work such as piping for installing the storage tank 12 is performed. Then, the outside of the side wall 29 is backfilled, and the upper surface opening of the underground pit 13 is covered with the floor slab concrete 35 and closed. The underground pit 1 around the storage tank 12
3 may be filled with sand or the like.

Next, the upper surface of the closed underground pit 13 and the pavement around it (vehicle running path 17) will be described. First, the earth and sand in the pavement construction area except the upper surface of the underground pit 13 is discharged to a predetermined depth (a discharging process) or backfilled to make the depth constant. Then, a crushed stone or the like is laid on the bottom of the hole and rolled to form a base layer 40 (a base layer forming step), and sand or a loose lightweight aggregate is laid horizontally on the base layer 40, That is, leveling is performed to form the leveling layer 41 (leveling layer forming step). Like the underground pit 13, the leveling layer 41 enables the foam blocks 24 to be lined up in a stable state and laid horizontally, and to prevent the laid foam blocks 24 from becoming uneven. Layer. And the leveling layer 4
When 1 is formed, the foam material block 24 is laid on the leveling layer 41 (foam material block laying step).

The foam material block 24 functions as a ground stabilizing material. As in the case of the underground pit 13, in this embodiment, a block made of expanded polystyrene having a width of 2 m, a length of 1 m, and a thickness of 50 cm (a styrofoam block 24) is used. ). When the styrofoam block 24 is laid, the styrofoam block 24 is laid while being connected using a tie-down fitting so as not to be separated from the adjacent one.

As the styrofoam block 24, in the case of the gas station 11 as in this embodiment, a flame-retardant one is used. In addition, since styrene foam is melted by a solvent such as gasoline or kerosene, a protective layer 42 is formed on the upper surface.
Is formed (protective layer forming step).

The protective layer 42 is formed by applying a material obtained by adding an inorganic crystal growth material to concrete. This inorganic crystal breeding material contains a water-soluble silicate and a magnesium fluoride compound as main components. The proportion of the inorganic crystal breeding material added may be about 10% to less than 10%.

The components of the inorganic crystal breeding material are, for example, 20% by weight of SiO2, 30% by weight of CaO, 5% by weight of NaO, and 2-3% by weight of insoluble components. The reaction of the inorganic crystal breeding material is a water-soluble silicate + Ca (OH) 2 → C—S—H type crystal, and a fluoride compound containing magnesia + Ca (OH) 2 → CaF2
+ MgSiO2 + αH2O. Reproduce the water-soluble silicate in the reaction, and generate extra H2O in the reaction,
The reaction is utilized in the reaction, that is, the reaction continues as a chain reaction. Then, C—S—H based crystal (needle-shaped) and CaF
2. MgO.nSiO2 (equiaxial, oblique) is entangled and becomes strong. Therefore, the strength of the concrete is improved by about 10 to 15% as compared with the non-coated one as measured after curing for 4 weeks. Then, as the time elapses, the reaction proceeds, and the strength can be increased by 28 to 30%.

Further, since this inorganic crystal breeding material is extremely fine, it can penetrate more than 30 cm into the concrete by capillary action and osmotic pressure action, and enters into small gaps such as pores and voids of the concrete to seal. By doing so, a dense organization can be achieved. Therefore, as shown in FIG. 9, it has a property of penetrating into the concrete cast on the protective layer 42, exhibits waterproofness (water stoppage), and reliably prevents penetration of gasoline, water, and the like. be able to. For this reason, even if cracks occur on the surface pavement described later, even if gasoline or water enters the cracks, oil such as gasoline separates from water and rises and evaporates. It hardly reaches the styrofoam. Even if the cracked oil such as gasoline falls, the protective layer 42 has the water-stopping property, so that it can be surely prevented from reaching or contacting the styrofoam block 24.

In addition, the above-mentioned dense structure contributes to the improvement of the strength, and also helps to prevent cracks. In the event that a crack occurs, it is self-repaired by the crystal growth of the inorganic crystal growth material, and is integrated again. Become

Other characteristics of the above-mentioned inorganic type crystal breeding material include deterrence against frost damage, deterrence against salt damage, deterrence against neutralization, deterrence against alkali-aggregate reaction, deterrence from hardening shrinkage, and chemical resistance.

The above-mentioned protective layer 42 is formed not only on the entire upper surface of the styrofoam block 24 laid but also on the upper surface of the slab concrete 35 which covers the opening of the upper surface of the underground pit 13. That is, the protective layer 42 is provided in front of the area where the surface pavement concrete is cast.
Is formed to prevent cracking of the concrete and to ensure protection of the Styrofoam block 24.

After the protection layer 42 is formed, next, concrete is cast on the protection layer 42 to form a surface pavement layer 4.
3 is formed (concrete casting step). When the surface pavement layer 43 is formed, concrete is cast after the reinforcing bars 44 are arranged vertically and horizontally.

In the case of arranging the reinforcing bar 44, in this embodiment, a reinforcing bar support 45 shown in FIG. 11 is used.
The rebar supporting bracket 45 is fixed by welding or the like in a state where the inverted members 47 having left and right downwardly directed legs 46 are respectively crossed substantially at a right angle at the center of the horizontal portion. Has a substantially S
And a pair of substantially S-shaped winding wires 49 which are open downward and have different directions in the horizontal portion of the other member. The installation surface index portion 50 is inserted downward, and a depth regulating portion 51 is extended.

In order to stop the reinforcing bar 44 by using the reinforcing bar support fitting 45 having the above-described configuration, a leg 46 longer than the restricting portion 51 is pierced into a predetermined position on the upper surface of the Styrofoam block 24 and inserted. Is sufficiently pierced until the lower end thereof contacts the upper surface of the Styrofoam block 24. Since the insertion depth regulating portion 51 is set to a predetermined length capable of holding the reinforcing bar 44 at an optimum height, the height of the reinforcing bar 44 can be reduced only by bringing the lower end into contact with the upper surface of the Styrofoam block 24. It can be located at the optimum height. It is desirable that the insertion depth regulating portion 51 has a contact area as large as possible by, for example, bending the lower end into an L shape so as not to pierce the styrofoam block 24.

After the reinforcing bar support 45 is disposed on the styrofoam block 24 in this manner, the reinforcing bar 44 is then inserted into the S-shaped winding wires 48, 49, and the winding wires 48, 49 are inserted. The reinforcing bar 44 is stopped by winding the tip portion of 49 around the driving surface indicator 50 and the insertion depth regulating portion 51. In this case, since the reinforcing bar 44 has a limit in length, the reinforcing bar 44 is actually joined in the middle, and the reinforcing bar 44 in the same direction is adjacent to the winding wire portion 48,
The respective rebars 44 are inserted into 49 and stopped. Then, the reinforcing bars 45 are arranged at the portions where the vertical and horizontal reinforcing bars 44 intersect, and each reinforcing bar 44 is supported. Therefore, as shown in FIG. 12, when a total of four reinforcing bars 44 cross (a), There are a case where three wires cross (b) and a case where two wires cross (c). However, since a pair of winding wires 48 and 49 are provided on the upper side and a pair of winding wires 48 and 49 on the lower side, all of these cases are used. Accordingly, each reinforcing bar 44 can be supported without difficulty.

When the work of arranging the reinforcing bar 44 is completed in this way, concrete is poured. At this time, FIG.
As shown in (d), when the upper end of the casting surface index portion 50 provided on the reinforcing steel support bracket 45 is used as a guide, the casting can be accurately performed to a predetermined thickness. Note that the casting surface indicator 5
The height of the upper end of 0 is adjusted in advance according to the thickness of the concrete suitable for the site.

In the case of the gas station 11, a column 52 for supporting the canopy 16 is often provided.
Is generally one step higher than its surroundings. In the present embodiment, when forming this base portion, as shown in FIG. 13, a concrete frame 55 molded in advance to a predetermined height is placed on the protective layer 42, and in this state, the frame 55 Cast concrete inside and outside. The bottom of the concrete frame 55 is formed in a shape protruding outward, and is configured to be pressed down by the poured concrete. A non-through hole 56 for supporting the reinforcing bar 44 is formed in an upper portion of an inner surface of the side wall 29 of the frame 55, and a through hole 57 for penetrating the reinforcing bar 44 is formed in a lower portion of the side wall 29 buried in the cast concrete.

When the above-described frame 55 is placed and concrete is cast, a raised base portion can be easily constructed. Then, the pillar 52 can be erected on the base portion.

In this way, when the surface pavement layer 43 is formed by placing concrete on the protective layer 42, the protective layer 42
The inorganic form crystal breeding material permeates into the concrete of the surface pavement layer 43 with the passage of time. Therefore,
The concrete of the surface pavement layer 43 is densely structured and the strength is improved, and the occurrence of cracks and fine hair cracks can be suppressed. Even if cracks occur on the surface pavement, the cracks are blocked because the inorganic crystal breeding material that continues to undergo a chain reaction penetrates. Even if gasoline or water previously flows into the crack, the gasoline or water is prevented from further penetrating by the protective layer 42 having the water blocking property. Therefore, the surface pavement layer 43
Even if cracks occur, the spilled gasoline can be reliably prevented from reaching the styrofoam block 24, and damage to the styrofoam block 24 due to adhesion of oils and fats can be reliably prevented.

A flame-retardant styrofoam block 24 is buried as a ground stabilizing material. However, since the upper surface of this styrofoam block 24 is covered with a protective layer 42 and concrete is cast on the protective layer 42, Even if a fire occurs on the surface pavement, the underground Styrofoam block 24 does not burn and there is no danger in fire prevention. The flame-retardant styrofoam block 24
Alternatively, the use of a non-combustible foam, such as a foam cement block, further reduces the fire hazard.

Another embodiment of the surface pavement layer 43 shown in FIG. 14 is a foam material block 2 such as a styrofoam block.
4 is provided with a snow melting mechanism. This snow melting mechanism
For example, a groove is formed on the upper surface of the Styrofoam block 24, and a snow-melting pipe 60 is provided in the groove.
The snow carried on the surface pavement layer 43 is melted by heat carried by a heat medium such as hot water passed through the inside of the pavement.

As described above, when the snow melting mechanism is provided on the styrofoam block 24, the heat can be efficiently prevented from escaping to the ground due to the heat insulating property of the styrofoam.
The heat radiated can be effectively used for melting snow. Therefore, a snow melting mechanism excellent in thermal efficiency can be provided. Note that the snow melting mechanism is not limited to a mechanism through which warm water is passed, but may be a mechanism provided with a heating wire, for example.

In the above embodiment, the gas station 11 has been described as an example. However, the present invention is not limited to this, and a tank for storing substances other than gasoline is buried underground. It may be a facility that did.

[0045]

According to the present invention as described above, the following effects can be obtained. According to the first and fifth aspects of the present invention, the floor portion of the underground pit is constructed by laying a foam material block on an uneven ground foundation layer, and placing a floor pavement layer in which concrete is cast on the foam material block. The pavement around the closed upper surface of the underground pit is laid with foam blocks on the uneven leveling layer, and water-soluble silicate and magnesium fluoride compound are placed on the upper surfaces of these foam blocks. Is formed by forming a protective layer by adding an inorganic crystal breeding material whose main component is concrete to concrete, and by forming a surface pavement layer on which concrete is cast on this protective layer. The necessary supporting force can be secured by the laid foam block without driving the pile. Therefore, even if the ground is soft, it is not necessary to drive the foundation pile, which not only eliminates the problems of vibration and noise associated with the pile driving work,
The construction period can be shortened by using a foam block that can be laid by workers manually, compared to the case of pile driving.
Also, construction costs can be saved.

Further, since the necessary supporting force is secured by the foam material block, in other words, since the supporting force is provided by a surface different from that of the point supported by the pile, the load applied to the surface pavement can be dispersed and carried. The amount can be reduced. Therefore, it is possible to reliably prevent the surface pavement from being cracked or cracked due to the concentrated load.

Further, on the upper surface of the foam material block, a protective layer is formed by adding an inorganic crystal breeding material containing a water-soluble silicate and a magnesium fluoride compound as main components to concrete, and concrete is cast on the protective layer. Since the provided surface pavement layer is formed, the concrete of the surface pavement layer can be densified by the inorganic crystal breeding material and the strength can be improved. Therefore, even if the concrete pavement surface is repeatedly shrunk due to cold and warm, generation of cracks and cracks can be suppressed, and frost damage in a cold region can be prevented.

The inorganic crystal breeding material has the property of penetrating into the concrete cast on the protective layer, and exhibits waterproofness (water-stopping property) to ensure penetration of gasoline, water and the like. Can be prevented. For this reason, even if a crack occurs on the surface pavement, it is possible to reliably prevent gasoline and water entering the crack from reaching the foam material block, and when styrofoam is used as the foam material block. Particularly useful.

Further, since the occurrence of cracks and cracks on the pavement surface can be effectively suppressed, the labor and cost for repair can be greatly reduced, and the maintenance can be simplified and simplified. .

According to the second aspect of the present invention, an inorganic crystal breeding material containing water-soluble silicate and a magnesium fluoride compound as main components is provided on the upper surface of the foam material block laid for constructing the floor of the underground pit. Since a protective layer added to concrete is formed and concrete is poured on this protective layer, the floor pavement layer is less likely to crack and exhibits water stoppage, similarly to the surface pavement layer of a vehicle traveling road. .
Therefore, even if the floor pavement layer is cracked or cracked, it is possible to reliably prevent gasoline and the like leaking from the tank from reaching the foam material block.

According to the third aspect of the present invention, since the block made of expanded polystyrene is used, the laying work is easy because of its light weight, which greatly contributes to shortening the construction period. In addition, since the expanded polystyrene block is excellent in heat insulation, when a snow melting mechanism is installed, thermal efficiency can be increased, and running costs can be reduced.

According to the fourth aspect of the invention, since the non-combustible foam concrete block is laid, the fire safety can be further enhanced.

[Brief description of the drawings]

FIG. 1 is a plan view of a gas station.

FIG. 2 is a sectional view of an underground pit.

FIG. 3 is a sectional view of an underground pit.

FIG. 4 is a plan view of an underground pit in which floor slab concrete is partially removed.

FIG. 5 is a perspective view of an underground pit.

6A is a sectional view of a side wall, and FIG. 6B is a perspective view of the side wall.

FIG. 7 is a sectional view of a vehicle traveling path.

FIG. 8 is a partially cutaway perspective view of a vehicle traveling path.

FIG. 9 is a sectional view of a vehicle traveling path.

FIG. 10 is a partially cutaway perspective view of a vehicle traveling path.

FIG. 11A is a perspective view of a reinforcing bar support, and FIG. 11B is a front view thereof.

FIG. 12 is an explanatory diagram showing a state where a reinforcing bar is supported,
(A) is an explanatory view showing a state in which four intersecting rebars are supported, (b) is an explanatory view showing three intersecting rebars, (c) is an explanatory view showing a state in which two intersecting rebars are supported, and (d) is an intersecting rebar. It is a front view which shows the state which supported.

13A is a perspective view of a frame, FIG. 13B is a plan view of the frame, and FIG. 13C is a cross-sectional view of the frame.

FIG. 14 is a partially cutaway perspective view of a vehicle running path provided with a snow melting mechanism.

FIG. 15 is a sectional view of a pavement layer supported by a friction foundation pile.

FIG. 16 is a plan view of a conventional gas station.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Gas station 12 Storage tank 13 Underground pit 14 Fire wall 15 Office building 16 Canopy 17 Vehicle running path 20 Automatic car wash 21 Car wash 22 Base layer 23 Leveling layer 24 Foam block (Styrofoam block) 25 Protective layer 26 Floor pavement layer 27 Reinforcing Bar 28 Stand 29 Side Wall 30 Supporting Wall 31 Foundation Block 32 Formwork 33 Holder 34 Reinforcing Bar 35 Floor Slab 40 Base Layer 41 Leveling Layer 42 Protective Layer 43 Surface Pavement Layer 44 Reinforcing Bar 45 Reinforcing Bar Support 46 Leg 47 Formed members 48, 49 Winding wire portion 50 Placing surface index portion 51 Insertion depth regulating portion 52 Column 55 Frame body 56 Non-through hole 57 Through hole 60 Snow melting tube

Claims (5)

[Claims] 1. An underground pit is formed by casting concrete at least at the bottom of a hole that has been excavated to a depth where a tank can be buried, a storage tank is installed in the underground pit, and a top opening of the underground pit is closed. At the same time, in a facility where the top surface of the closed underground pit is paved with concrete at the same height as the surrounding area, the floor of the underground pit is laid with foam blocks on uneven leveling layers, and these foam blocks are The pavement around the closed upper surface of the underground pit is laid with a foam block on the uneven leveling layer. On the upper surface, a protective layer formed by adding an inorganic crystal breeding material mainly composed of a water-soluble silicate and a magnesium fluoride compound to concrete is formed. Structure of the facility the storage tank, characterized by being configured by forming a surface pavement layer was Da設 concrete and buried underground to. 2. The floor of an underground pit is constructed by laying a foam material block on an uneven foundation layer, and an inorganic material mainly composed of a water-soluble silicate and a magnesium fluoride compound on the foam material block. The storage tank according to claim 1, wherein a protective layer is formed by adding a system crystal breeding agent to concrete, and a floor pavement layer in which concrete is cast is formed on the protective layer. The structure of the facility buried underground. 3. The structure of a facility having a storage tank buried underground according to claim 1, wherein the foam material block is a block made of expanded polystyrene. 4. The structure of a facility having a storage tank buried underground according to claim 1, wherein the foam material block is a foam concrete block. 5. An underground pit is formed by casting concrete at least at the bottom of a hole that has been excavated to a depth at which the tank can be buried, a storage tank is installed in the underground pit, and an upper opening of the underground pit is closed. At the same time, when constructing a facility in which the top surface of the closed underground pit is paved with concrete at the same height as the surrounding area, the floor of the underground pit will have a leveling layer to form a leveling layer by leveling the bottom of the hole. Pavement around the closed upper surface of the underground pit by constructing through a process, a foam block laying process of laying a foam block on the leveling layer, and a concrete casting process of casting concrete on the foam block. A leveling layer forming step of forming a leveling layer by adjusting unevenness, and laying a foam block on the leveling layer to lay a foam material block A protective layer forming step of forming a protective layer by adding an inorganic crystal breeding material containing water-soluble silicate and magnesium fluoride compound as main components to concrete on the upper surface of the foam material block; A method of constructing a facility in which a storage tank is buried underground, which is constructed through a concrete placing step of placing concrete.