JPS6068282A - Prestressed concrete tank - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a slip-rest female concrete tank for storing liquids such as water, petroleum, or low-temperature liquefied gas.

Generally, this type of tank has a tom roof (1), side walls (2
) and a bottom plate (3), and the connecting part between the side wall (2) and the bottom plate (3) can be of a sliding type, a hinge type, a fixed type, etc. depending on the purpose and scale. ing.

In the slide type structure, as shown in Figure 2, the side wall (2) and the bottom plate (3) are completely insulated (so that the side wall (2) can freely center against circumferential prestress and water pressure. Since it can be displaced in the direction, it has the advantage of being able to apply a complete prestress in the circumferential direction and not generating a bending moment in the vertical direction.
It is extremely difficult to maintain liquid tightness over a long period of time.

In the sheep type structure, as shown in Figure 3, the side wall (2) and the bottom plate (3) are hinged, and a vertical bending moment occurs at the lower end of the side wall. A bending moment larger than that of the method is generated, and a large amount of prestressing steel (A) is required in the vertical direction.Also, since the displacement of the lower end of the side wall toward the center is restrained, the lower end of the side wall is It is not possible to introduce compressive force due to prestress, and cracks are likely to occur due to drying shrinkage or temperature changes.Furthermore, with this method, it is also difficult to maintain liquid tightness of 4°C.

In addition, in the fixed type structure, as shown in Figure 4 (C5
The side wall (2) and the bottom plate (3) are rigidly connected, and the liquid tightness is the best, but the circumferential prestress and the hydraulic pressure 1
(Thus, a large vertical bending moment occurs at the lower end of the side wall. Therefore, a PC steel plate is required in the vertical direction. Also, since the displacement of the lower end of the side wall toward the center is restrained, the hinge As in the case of this method, it is not possible to introduce compressive force due to prestress in the circumferential direction to the lower part of the side wall.

The present invention has been proposed in order to solve these problems, and the corner portion that connects the tank side wall and the bottom plate is made into a continuous curved shell structure, and the corner part that connects the tank side wall and the bottom plate is made into a continuous curved shell structure, and the corner part that connects the tank side wall and the bottom plate is made to have a continuous curved shell structure, and the corner part that connects the tank side wall and the bottom plate is made to have a continuous curved shell structure. This relates to a prestressed concrete tank characterized by having a horizontally movable sliding layer provided therebetween.

As described above, in the prestressed concrete tank according to the present invention, the corner portion that connects the tank side wall and the bottom plate is changed from the orthogonal structure as in the conventional method.
By forming a continuous curved shell structure for smooth stress transmission, and by providing a horizontally movable sliding layer between the bottom plate and the base plate and directly under the side walls sandwiching the corner part, the corner part horizontal displacement is no longer restricted, and the generation of secondary stress in the out-of-plane direction can be suppressed to a small level.

In addition, by creating a curved shell structure at the lower corner of the side wall to facilitate deformation in the radial direction, sufficient compressive force can be introduced in the circumferential direction through prestress, preventing drying shrinkage and temperature changes. This can prevent the occurrence of cracks due to

Further, if necessary, the axial PC steel materials that were separately arranged on the side walls and the bottom plate can be made into continuous and identical pieces, and the PC steel material fixing device can be saved.

As described above, according to the present invention, an economical prestressed tank with excellent liquid tightness, thin member thickness, and small amount of prestressed steel material is provided.

The present invention will be described below with reference to the illustrated embodiments.

In Figures 5 and 6, (the mark is the dome roof of the prestressed concrete tank, θ4 is the side wall, 03 is the bottom slab, and the curved shell side that connects the side wall 02) and the bottom slab (13) is continuous. The course part (1
4) and the bottom plate 031 and the side wall (12) are installed on the base plate (1″3). PC steel (1G) is arranged in the circumferential direction to counteract the long sword, and prestress is introduced by the PC steel (16).In addition, if necessary, the bending moment in the out-of-plane direction is Axial PC steel (16') is placed for resistance.

The bottom plate (13) is formed in a disk shape or a ring shape,
A sliding layer (17) is interposed between the base plate 05 and the base plate 05, and is supported on the base plate 05 without equally restraining horizontal displacement due to external forces, temperature changes, etc.

The side wall (the base plate (I5) below Id of I2 is formed in a trapezoidal shape, and there is a sliding layer between the top surface of the turn and the bottom surface of the side wall circle! 08)
However, the sudden weight of the dome roof (11) and side walls (1) is directly transmitted to the foundation plate (15), but the corner part (15)
4), and is therefore constructed so as not to be restrained against horizontal displacement due to prestress, external force, temperature change, etc. A buffer 44' (19) is interposed between the corner portion 0 and the base plate (151), or a space is left open to allow free deformation.

Furthermore, uneven loads that act on the entire tank, such as horizontal forces during earthquakes, can be resisted by ring-shaped horizontal movement prevention protrusions (2 (1)) protruding from the outer periphery of the base plate (). In addition, if the unbalanced load is small, the horizontal movement prevention protrusion (20) is not provided, and the Go+1 circle and the cushioning material (
It is also possible for the base plate 05) to take charge via I8).

In the illustrated embodiment, as described above, the side wall (12)
and the bottom plate 03) is changed from the conventional orthogonal structure to a curved shell structure with smooth stress transmission, and the horizontal displacement is not restricted by the sliding layer Q7) (18!). By doing so, it is possible to suppress the generation of secondary stress in the out-of-plane direction, and as mentioned above, by making the corner part (( In order to be able to introduce a compressive force of →- in the direction as well by prestress, Ic is small.

7 to 9 show other embodiments of the present invention.

As a means of resisting eccentric loads such as seismic horizontal force, a shear key c21+ with a convex cross section extending radially from the center to the outer circumference is provided on the bottom surface of the bottom plate (I3), and
15) A four-strip groove is provided to which the shear key 112+1 engages, thus controlling the prestress, the liquid pressure in the tank, the gas pressure,
In response to a uniform axisymmetric load such as a temperature change, the base plate (1) can be freely deformed in the radial direction, but in response to a non-axisymmetric horizontal load, the base plate ( 15
)K transmits shear force.

The present invention has been described with reference to two embodiments, and although the present invention is limited only to such embodiments, modifications of the divine design may be made without departing from the spirit of the invention. It is something that can be done.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional front view of the left half showing an outline of a prestressed concrete tank, Figs. 2 to 4 are longitudinal sectional views showing the joint structure of the conventional side wall and Mr. 1 plate, respectively, and Fig. 5 is the invention of the present invention. FIG. 6 is an enlarged view of the main parts, and FIGS. 7 to 9 show other embodiments of the prestressed concrete tank according to the present invention. The figure is a plan view of the tank bottom plate.
FIG. 58 is a longitudinal sectional view of the bottom of the tank, and FIG. 9 is a view taken along arrow IX-fX in FIG. 8. ([2)...Side wall (13)-...Bottom plate 04)...
Corner part (15)...Foundation plate (t7)...Sliding layer agent Patent attorney Shige Okamoto Six outsiders Figure 1 Figure 2 Figure 31

Claims (1)

[Claims] A prestressed concrete characterized in that the corner part that connects the tank side wall and the bottom plate has a continuous curved shell structure, and a sliding layer that is movable in the horizontal direction is provided directly below the side wall and between the bottom surface of the bottom plate and the foundation plate. tank.