JPS5839718B2 - Underground tanks for storage of crude oil, liquefied gas, etc. - Google Patents

Description

[Detailed Description of the Invention] The underground tank for storing crude oil, liquefied gas, etc. according to the present invention is capable of smoothly discharging stress at the even corner portion of the connection between the side wall and the bottom plate, and also allows stress generated from the temperature difference occurring at the bottom portion to flow smoothly. In other words, in an underground tank made of reinforced concrete, the inner surface of the joint between the tank side wall and the bottom plate is formed into a tapered shape in cross section, and the tapered portion is A water-permeable layer is formed on the mortar-shaped bottom of the bottom plate formed by the method, and the water-permeable layer is covered with a concrete floor plate.

In general, in underground tanks, a large load is applied to the lower surface of the tank bottom plate due to the influence of groundwater pressure, frost heaving pressure, or temperature.
A large bending moment is generated at the joint between the bottom plate and the side wall.

On the other hand, for the joint structure between the bottom plate and the side wall of the tank, a rigid connection method is desirable from a functional standpoint, especially in the case of a reinforced concrete tank, but rigid connections cause excessive stress concentration at the side corners, making the tank more likely to break. For these reasons, the joint between the bottom plate and the side wall is made into a hinge structure as shown in FIG. 53-479
No. 22), etc., but with such a hinge structure,
They have drawbacks such as being inferior to rigidly bonded ones in terms of the amount of deformation of interior materials such as membranes and water-stopping properties.

In addition, in underground tanks, in order to cope with the pumping pressure, the bottom plate is sometimes thickened to increase the tank's own weight and prevent the tank body from floating up, but if the bottom plate is thick, the LN
Temperature stress generated from the difference in temperature between ultra-low temperature stored materials such as G and underground temperature becomes a problem, and unreasonable force is applied to the bottom plate, etc., so it is necessary to deal with this.

Furthermore, if the pneumatic caisson method is used as a construction method, even if the hole on the bottom slab is later covered with concrete when Manlock, Material Rock, etc. are used, the joint becomes a source of leakage, causing the tank to leak. This may deteriorate the performance of the insulation material of the tank and have an adverse effect on the tank itself.

This invention solves the above-mentioned problems by rigidly connecting the tank bottom plate and the side wall. Next, an embodiment will be explained with reference to the drawings. The inner surface 4 of the connecting portion is formed to have a tapered cross section, and the tapered inner surface 4 of the joint portion is formed into a tapered shape in cross section.
A permeable layer 5 made of a porous material such as gravel is formed on the mortar-shaped bottom of the bottom plate 3 formed by the above, the permeable layer 5 is covered with a concrete floor plate 6, and a pipe 1 is buried in the side wall 2. The tip of the pipe 7 is inserted into the water-permeable layer 5, and water at an appropriate temperature is passed through the pipe 7 and the water-permeable layer 5 using the supply or drainage pumps 8, 9.

Further, the concrete floor plate 6 is formed to have a thin wall with low rigidity to hold the tank inner tank 10.

The underground tank of this invention has the above-mentioned configuration, and has a water permeable layer 5.
acts as a hot water heater and has the following effects.

(1) By forming the inner surface of the joint between the side wall and the bottom plate into a tapered shape in cross section, sudden changes in the cross section can be avoided even if the joint is a rigid joint, and the stress can be reduced. flows smoothly, so stress concentration hardly occurs.

(2) Reduction in temperature stress Since water can be passed through the permeable layer on the bottom plate and used as a hot water heater, the temperature stress occurring in the bottom plate can be considerably reduced.

When constructing a tank using the pneumatic caisson construction method, it is almost impossible to install a hot water heater under the bottom slab because fire cannot be used for work under the bottom slab. There is a hot water heater on top, so you can install it without any problems.

(3) Measures against water leakage from the bottom plate Since water leaking from the bottom plate is guided to the permeable layer and pumped up, water leakage will not cause a decline in the performance of the insulation material or have any other negative impact on the tank body.

(4) Lower construction costs As a result of (1) to (3), significant cost reductions can be expected, such as savings in construction materials and simplification of processes.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view showing an embodiment of the present invention, FIG. 2 is a sectional view of a main part of the same, and FIG. 3 is a sectional view showing a conventional example. 1...Underground tank, 2...Side wall, 3.
...Bottom plate, 4...Inner surface of joint part, 5...
... Permeable layer, 6... Concrete bottom plate.

Claims (1)

[Claims] 1. In an underground tank made of reinforced concrete, the inner surface of the joint between the side wall of the tank and the bottom plate is formed into a tapered shape in cross section, and a permeable layer is formed in the mortar-shaped bottom of the bottom plate formed by the tapered part, and the permeable layer is An underground tank for storing crude oil, liquefied gas, etc. whose top is covered with a concrete floor plate.