JPH0912089A - Structure for protecting liquid-proofing dike of tank - Google Patents

Abstract

PURPOSE: To prevent reserved liquid leaking from a tank from flowing outside even if a dike sinks, tilts, falls down or is damaged by cracks or the like due to liquefaction of the tank yard ground when an earthquake occurs. CONSTITUTION: A protection dike 3 is formed of a ring-like float 11 and a wall material 12 provided upward from the float 11, and the protection dike 3 is installed in a non-fixed state on the ground separately from an entire inner periphery of a liquid-proofing dike 2, wherein the protection dike 3 is formed of a volume of the float 11 which has such buoyancy that the float sinks while receiving reserved liquid leaking from a tank without overflowing with the water material 12 and it floats in fluid such as soil including water or liquefied water, and a weight of the protection dike 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protection structure for an oil levee, a liquid levee, or a partition levee (hereinafter referred to as liquid levee) of a tank for storing liquid dangerous substances such as petroleum or low temperature liquefied gas. is there.

[0002]

2. Description of the Related Art Around a tank 1 for storing liquid dangerous substances such as petroleum or low temperature liquefied gas, as shown in FIG. In order to prevent this, a liquid barrier 2 is provided.

The levee 2 is safe against its own weight, earth pressure, hydraulic pressure, earthquake effects, temperature changes and other loads,
And it is made of reinforced concrete or earth as safe against stress caused by load. FIG. 6 shows a case of a general levee 2 having a reinforced concrete structure. The liquid levee 2 is formed in an inverted T shape from a foundation 9 consisting of a bottom slab 7 at the lower end portion embedded in the ground 6 and a footing 8 and a wall body 10 standing upright on the foundation 9.

The volume of the liquid barrier 2 surrounded by the wall 10 of the liquid barrier 2, the height of the wall 10 of the liquid barrier 2, and the like are defined by law. In addition, regarding the influence of the earthquake, the inertial force at the time of the earthquake, the earth pressure at the time of the earthquake, and the hydraulic fluid at the time of the earthquake are taken into consideration, and a predetermined safety factor has been established for the bearing capacity, sliding, and overturning of the dike 2. .

[0005]

The tank yard 4 is often installed on a soft ground 6 such as a landfill or a land reclamation site such as a seaside or river basin, and when a groundwater level is high or a sandy place, an earthquake occurs. There was a risk of liquefaction phenomenon in which the entire ground became liquid when subjected to strong vibrations at, and sand and water increased to high pressure underground and spouted. In this case, the liquefied ground will be in a state where sand is mixed in the water, heavy things in the sand will sink, and light things will rise. In such a case, the large liquid levee 2 with a specific gravity of the reinforced concrete structure of about 2.5 may sink to the loose ground 6, tilt, fall, or be damaged by cracks. there were.

Further, at this time, when a storage liquid such as petroleum or low temperature liquefied gas having a specific gravity smaller than 1 in the tank 1 leaks from the tank 1, these storage liquids are liquefied water or liquefied water having a specific gravity larger than 1 generated by the earthquake. It is thought that there is a possibility that it may float on the earth and sand containing the water, overrun the liquid barrier 2 that is damaged by sinking or tilting, and may flow out of the tank yard 4 to cause a great disaster. Similarly, it is also considered that the levee made of soil may damage the ground and the levee due to the liquefaction phenomenon caused by the earthquake and may not be able to receive the leaked storage liquid.

The present invention has been made in view of these problems, and even if the dike is submerged, tilted, overturned, or cracked due to the liquefaction phenomenon of the ground of the tank yard at the time of an earthquake, It is intended to provide a protection structure for a tank levee that prevents leaked stored liquid having a specific gravity of 1 or less from flowing out of the tank levee.

[0008]

The tank levee protection structure of the present invention comprises a ring-shaped float and a wall material provided upward from the float to form a protection dam, and It is installed on the ground in a non-fixed state so as to be separated from the entire inner circumference of the levee, and even if the float above receives buoyancy against the stored liquid leaking from the tank, the protective levee keeps the stored liquid leaking from the tank. The total weight of the above wall materials and float so that the float receives buoyancy against the fluid such as earth and sand containing water or liquefied water that sinks and sinks without overflowing with the above wall material and floats the bank. And the above-mentioned dike is formed by the volume of the float.

In addition, the above-mentioned protective bank is formed so that an elastic material is provided on the outer surface of the wall material of the protective bank so that the elastic material comes into contact with the inner surface side of the tank liquid bank and is slidable. is there.

Further, the protection dam is formed by forming a float of the protection dam into a hollow closed ring shape and partitioning the hollow ring-shaped portion in the circumferential direction into a plurality of sealed partition chambers.

Further, the above-mentioned protection dam is provided with a float of the protection dam in a pit formed in the shape of a bottomed open drain on the ground at a position lower than the ground surface.

[0012]

The tank levee protection structure of the present invention comprises a ring-shaped float and a wall material provided upward from the float to form a protection levee, and the protection levee is formed around the inner circumference of the liquid levee. Since it is installed on the ground in a non-fixed state, it is independent of the protection dike in the event of an earthquake because it is a separate body from the dike. Also, due to the liquefaction phenomenon of the ground caused by the earthquake, water or soil containing water is ejected from the ground to weaken the ground, causing the heavy dike to sink or tilt and partially collapse, causing damage such as cracks. Even so, since the protection dike is a separate body from the liquid dike and behaves independently,
They will not be damaged by being pulled into a heavy dike and sinking or tilting together.

Further, the protective bank has a specific gravity of 1 leaked from the tank.
Even if the float receives buoyancy, it does not float up against smaller stored liquids because it has a small buoyancy, while it contains water with specific gravity greater than 1 or liquefied water generated by the liquefaction phenomenon due to an earthquake. For the fluid such as earth and sand, because the float receives the buoyancy force from the liquid to float, the protective dike is formed by the total weight of the wall material of the dike and the float and the volume of the float. Even if water or soil containing water is generated by the liquefaction phenomenon, the float itself floats on the softened ground due to buoyancy. Therefore, the protection dike will not be damaged by sinking, tilting, partially deforming or cracking in the weakened ground. In addition, even if the stored liquid with a specific gravity of less than 1 leaks, the float has a small buoyancy with the stored liquid with a specific gravity of less than 1. Therefore, the float of the protective dike does not rise and is grounded on the ground, so It does not overflow with the material and does not flow outside. As described above, even if the levee is damaged by the liquefaction phenomenon caused by the earthquake, the levee is not damaged, and the liquid leaked from the tank can be received while maintaining the airtight and liquidtight structure.

In addition, the protection dam is formed so that an elastic material is provided on the outer surface of the wall material of the protection dam, and the elastic material elastically abuts on the inner surface side of the tank dam and is slidable. Therefore, even if the levee and the levee shake greatly due to an earthquake, they will elastically contact with each other through the elastic material and will not be damaged. In addition, even if the stored liquid in the tank leaks and flows and hits the wall material of the levee bank strongly, the impact force is dispersed through the above-mentioned elastic material provided on the outer surface to soften the wall material of the levee wall located outside. Since it hits elastically, both the protective dike and the liquid dike will not collide and be damaged. Furthermore, when the elastic material is formed of a heat insulating material and the wall material is formed of a low temperature steel material, the cold heat of the low temperature storage liquid is relaxed through the heat insulating material and the space formed between the liquid bank and the bank. However, since the cold heat of the low temperature storage liquid is not rapidly transmitted to the outer levee wall, damage to the levee due to thermal shock is prevented. In this way, a double safety liquid bank protection structure suitable for a liquid bank of a low temperature tank that receives the leaked low temperature storage liquid is obtained.

Further, since the protection dam is formed by forming a float of the protection dam into a hollow closed ring shape and partitioning the hollow ring-shaped portion in the circumferential direction into a plurality of sealed partition chambers, for example, an earthquake or the like. Therefore, even if a part of the partition chamber of the float is damaged and the buoyancy of the part is lost, the floating function of the entire float is not impaired. Further, when a part of the float is damaged and leaks, it is possible to efficiently detect the leaked portion and repair the leaked portion for each partition chamber in the partitioned range.

Further, since the above-mentioned dike is provided in the pit formed in the shape of an open-bottomed open bottom in the ground at a position lower than the ground surface, water generated by the earthquake or fluidized water It is easy to collect the sediment containing in the pit lower than the ground surface, and the sediment containing the inflowing water or the fluidized water gives buoyancy to the float in the pit to make it float up smoothly, and the protection dike rises to a predetermined height. To maintain. When the stored liquid having a specific gravity of less than 1 leaks, the float receives a small buoyancy, so that the stored liquid does not float and sinks and the protective dike descends, and the stored liquid is received without overflowing the protective dike.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments will be described with reference to the drawings. FIG.
The case where the protective bank 3 according to the present invention is provided around the tank 1 around the entire inner position of the liquid bank 2 so as to be separately provided without being fixed in a separate manner. FIG. 2 shows that the ground 6 is liquefied by a large-scale earthquake, and the levee 2 sinks into the weakened ground 17 and is damaged. In addition, the earthquake damages the tank 1 and the stored liquid. 5 shows the state in which the stored liquid 5 is received by the protection bank 3 provided with the ring-shaped float 11.

In the case of the levee concrete structure dike 2,
The liquid barrier 2 is formed in an inverted T-shape from a base 9 composed of a bottom slab 7 at the lower end portion embedded in the ground 6 and a footing 8 and a wall 10 standing upright on the base 9. This dike 2
The protective bank 3 is provided around the entire circumference of the tank 1 with a predetermined space inside. The protective bank 3 is formed by a ring-shaped float 11 made of a buoyant body at the lower end and a wall material 12 made of a flat plate upward from the float 11, and the upper end of the protective bank 3 is the liquid bank. It is provided so as to extend from the upper end of the second wall body 10.

The float 11 of the buoyant body is a refractory / heat-resistant member made of steel or the like, and has a rectangular cross section or a circular cross section, and is formed of a hollow closed hollow cylindrical body or a whole lightweight material having no hollow. , A material that does not corrode or an outer surface is coated with an anticorrosion coating. The flat plate wall material 12 is made of a fire-resistant / heat-resistant material such as steel, and is formed of an airtight / liquid-tight rigid material.
A material that does not corrode or the outer surface is formed by anticorrosion coating or the like. The protective bank 3 formed in this way will be described in detail later, but it is placed on the ground 6 or a part of the lower part of the float 11 so that it can float up and down by earth and sand containing water or liquefied water and move vertically. The whole is buried in the ground 6 and set aside.

When the storage liquid 5 having a specific gravity smaller than 1 leaks, the levee 3 has a small buoyancy in the float 11 when the float 11 is submerged in the storage liquid 5, so that the float 11 is at the bottom of the storage liquid 5. The levee of the float 11 is large when the float 11 is submerged in water or the like having a specific gravity of more than 1 or sediment containing water that is liquefied, while the levee 3 does not rise. The protection bank 3 is constructed by setting the total weight of the wall material 12 member and the float 11 member that configure the protection bank 3 and the volume of the float 11 that receives the buoyancy so that 3 floats in water or the like.

If necessary, on the outer surface of the wall material 12 of the protection dam 3, reinforcing materials 13 made of a rigid member such as a ring shaped steel are provided at predetermined vertical intervals in the circumferential direction. In addition, as shown in the figure, when it comes in contact with the dike 2,
An elastic material 14 made of a fireproof / heatproof elastic member is provided at the tip of the reinforcing material 13, and the protective bank 3 is formed so as to elastically and slidably contact the liquid bank 2. Also, the wall material 12
Is provided with a connecting member 15 at the upper end thereof, and a supporting member 16 made of the same member as the elastic member 14 is provided at the lower portion of the connecting member 15 to elastically connect with the upper end of the wall body 10 of the liquid levee 2. It is formed so as to abut and cover the upper portion to close it.

As shown in FIG. 2, when groundwater or earth and sand containing water erupt from the ground due to a large earthquake and the ground 6 causes a liquefaction phenomenon, the liquefied soft ground 17 causes a heavy load on the concrete structure. The liquid levee 2 is partially sunk or tilted, and cracks 18 or the like are generated in the wall body 10 to damage it. In such a case, the above-mentioned dike 3 is the dike 2
Since it is a separate body and does not combine with, and it behaves independently, and because the float 11 is provided, it is submerged in water or earth and sand and slopes and is not liquified on the liquefied ground 17 It floats and is not damaged by the liquefaction phenomenon.

Further, when the tank 1 is damaged due to an earthquake and the storage liquid 5 leaks, as described above, the dike 2 is damaged due to sinking or the like and cannot receive the storage liquid 5. 3 float 11 is liquefied ground 1
Since it does not get damaged by being sunk or tilted in 7 and does not float up to the stored liquid 5 having a specific gravity smaller than 1, the lower end of the float 11 is the ground 17 below the stored liquid 5.
The storage liquid 5 is grounded above and received by the wall material 12 without overflowing, and the storage liquid 5 does not flow out.

Further, as described above, since the elastic material 14 is provided at a predetermined position on the outer surface of the wall material 12 of the protection bank 3, the protection bank 3 may come into contact with the wall surface 10 of the liquid protection bank 2 or strongly due to a large shaking due to an earthquake. Even if it hits, since it elastically hits through this elastic material 14, neither the liquid-proof dike 2 nor the protective dike 3 is damaged. Further, even if the leaked storage liquid 5 flows and collides strongly with the wall material 12 of the protection bank 3, the impact force is dispersed and relaxed through the elastic material 14, and the wall body 10 of the liquid bank 2 located outside is relaxed. Since it hits elastically, the liquid bank 2 and the bank 3 are not damaged by the leaked force of the stored liquid 5.

When the elastic material 14 is formed of a heat insulating material and the wall material 12 is formed of a low temperature steel material or the like, it is composed of the space between the liquid-proof dike 2 and the protective dike 3 and the heat insulating material. Since the cold heat is transmitted through the elastic material 14, the cold heat of the low temperature storage liquid is not directly transmitted to the wall body 10 of the outer dike 2 and no thermal shock is applied. Therefore, the wall body 1 made of a concrete body or the like by the rapid cooling.
No heat damage to 0 occurs. In this way, the protection structure of the double safety liquid barrier 2 that gently receives the leaked low temperature storage liquid 5 by reducing the heat effect is provided.

FIG. 3 shows another embodiment of the protection dam 3A. The float 11A of the protective bank 3A is formed in a ring shape along the circumferential direction of a hollow having a sealed space inside, and a partition 19 for circumferentially partitioning the hollow portion is provided to form a plurality of independently sealed partition chambers 20. To do. Since the partition chamber 20 that is independently sealed is formed in this manner, even if a part of the partition chamber 20 of the float 11A is damaged due to an earthquake or the like and its buoyancy is lost, the floating function of the entire float 11A is not impaired. Also,
The inspection and repair of the damaged portion of the float 11A can be sequentially performed efficiently for each partition chamber 20 in the partitioned range.

The float 11A shown in FIG. 3 shows a case where the inner vertical wall surface is formed by extending the wall material 12A downward and used together. In this way, the float 11A becomes the wall material 1
It becomes a reinforcing member that reinforces the lower outer periphery of 2A in a ring shape, and the strength of the protective bank 3A in the circumferential direction increases. Further, the production cost can be reduced and the work efficiency can be improved by dividing each of the partition sections and manufacturing the float 11A and the wall material 12A integrally in the factory, and connecting and assembling the divided pieces on site.

In FIG. 4, a pit 21 formed in the shape of an open bottom with a bottom is provided in the ground 6 at a position lower than the ground surface along the entire inner circumference of the liquid levee 2, and the pit 21 is surrounded by the outer wall of the protective levee 3B. The case where the wall surfaces are separated from each other is shown. The float 11B of the protective bank 3B is formed so as to float on the water in the pit 21 provided in the ground 6 of the tank yard 4 and smoothly move up and down. When water or liquefied earth and sand containing water flows into the pit 21, the float 11B smoothly floats and maintains a predetermined height. Further, the protection bank 3B moves vertically without tilting or falling down due to the earthquake, and even if the stored liquid 5 in the tank leaks, the stored liquid 5 does not float up and can receive the stored liquid 5. it can.

The pit 21 shown in FIG. 4 is a pit 21 located at a position lower than the ground surface with water or soil containing water generated when the ground 6 of the tank yard 4 undergoes a liquefaction phenomenon due to an earthquake.
Since it is easy to collect it inside, the liquefied water and the sand that have partially generated in the tank yard 4 are collected in the pit 21 and averaged to improve the vertical movement of the protection dike 3B to a predetermined height position as described above. maintain. Also, in normal times, the tank yard 4
It can be used for drainage channels such as rainwater circulating around the inside, and when groundwater level is high, the drainage can be adjusted by communicating with the groundwater to lower the groundwater level and lower the groundwater level of the ground 6 in the tank yard 4. It can also prevent softening.

Although the liquid levee 2 shown in FIGS. 1, 2 and 4 has a concrete structure, the liquid levee 2 constructed with soil also has an inner side of the liquid levee 2. By providing the same protection dike 3 around the entire circumference at a predetermined interval, the same effect as described above can be obtained without being damaged by subsidence or the like against the liquefaction phenomenon caused by an earthquake.

[0031]

The protection structure for the tank dike of the present invention is
A ring-shaped float and a wall material provided upward from the float form a protective bank, and the protective bank is installed on the ground in a non-fixed state so as to be separated from the entire inner circumference of the liquid bank. Even if there is an earthquake, it behaves independently of the dike. Therefore, even if water or liquefied sand containing water is ejected from the ground due to the liquefaction phenomenon of the ground due to the earthquake and the foundation is weakened and the levee is submerged or tilted and damaged, the levee is the levee. Since it is a separate body, it behaves independently and is not damaged at the same time. When the dike is soaked in the storage liquid leaked from the tank, it sinks while the storage liquid is received by the wall material without overflowing it, whereas the dike contains water generated by the earthquake or liquefied water. The liquefaction phenomenon caused by the earthquake occurred because the weight of the wall material and the float volume and the volume of the float were used so that the float would float when the float was immersed in a fluid such as However, the dike is not subsided or inclined and damaged. Therefore, even if the stored liquid leaks, the protective bank receives the stored liquid and does not let the stored liquid flow out to maintain safety.

An elastic material is provided on the outer surface of the wall material of the protective bank, and the elastic material is slidably contacted with the inner surface side of the tank liquid bank. Even if it strongly hits the wall material of the protective levee, the load is elastically received and the stored liquid can be safely received without being damaged. Furthermore, when the protective bank is made of a low temperature material, a double safety liquid bank protection structure can be obtained which receives the cold heat of the low temperature storage liquid without directly transmitting it to the liquid bank.

In addition, the float of the bank is formed in the shape of a hollow ring, and the hollow ring is partitioned in the circumferential direction to form a plurality of sealed partitions. Even if it is damaged, the function of the entire float is not impaired, and the leaked storage liquid can be safely received.
In addition, maintenance of floats on the bank and repairs when damaged can be done efficiently.

Further, the protective dike provided in the pit formed in the shape of an open bottom with the bottom of the dike of the dike on the ground lower than the ground surface makes it easy to collect water and liquefied sand containing water in the pit. , Vertical movement in the pit becomes smooth. Further, it is possible to maintain a predetermined height of the protective bank and safely receive the leaked storage liquid.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional explanatory view in which a protective bank according to the present invention is provided inside a tank liquid bank.

FIG. 2 is a vertical cross-sectional explanatory diagram showing a case where the ground causes a liquefaction phenomenon to sink the liquid bank and an outflow of the stored liquid is received by the protective bank.

FIG. 3 is an explanatory view with a part omitted showing another embodiment of the protection dike.

FIG. 4 is a vertical cross-sectional explanatory view showing a case in which a protective bank is provided in a pit formed in the ground.

FIG. 5 is an explanatory view showing a conventional tank liquid barrier.

FIG. 6 is a vertical cross-sectional explanatory view showing a conventional liquid barrier having a reinforced concrete structure.

[Explanation of symbols]

1 tank 11, 11A, 11B
Float 2 breakwater 12, 12A, 12B
Wall material 3, 3A, 3B Protective bank 13 Reinforcement material 4 Tank yard 14 Elastic material 5 Storage liquid 15 Connecting material 6 Ground 16 Support material 7 Bottom plate 17 Ground 8 Footing 18 Crack 9 Foundation 19 Partition 10 Wall 20 Partition room 21 Pit

Claims (4)

[Claims] 1. A ring-shaped float and a wall material provided upward from the float to form a protection dam, and the protection dam is separated from the entire inner circumference of the liquid dam to the ground in a non-fixed state. For the fluid such as earth and sand containing water or liquefied water, which is installed stationary and sinks in the state where the protection bank receives the storage liquid leaked from the tank without overflowing with the wall material. A protective structure for a tank dike, which is formed by the volume of a float that causes floating buoyancy and the weight of the dike. 2. An elastic material is provided on the outer surface of the wall material of the protective bank, and the elastic material is formed by slidably abutting the inner surface side of the tank liquid bank. Tank dike protection structure. 3. The float according to claim 1, wherein the float of the protection bank is formed in a hollow ring shape, and the hollow ring-shaped portion is circumferentially partitioned into a plurality of closed partition chambers. Tank dike protection structure. 4. The tank liquid-proof according to claim 1, 2 or 3, characterized in that the float of the protective dike is provided in a pit formed in the shape of a bottomed open drain on the ground at a position lower than the ground surface. Levee protection structure.