JPS5916623B2 - Underground tank construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to an underground tank for storing liquids, such as liquid fuel, clean water, etc.

When storing liquid, if the head is made smaller, the structural strength of the plant does not need to be so large; however,
If there are restrictions on the installation area, the tank height (0) must be increased.

However, if the tank height is increased and the head becomes larger, the load placed on the plants will inevitably become very large. Therefore, in recent years, the idea of constructing plants underground to resist the pressure inside the tank against the ground has been born.

In this case, only the compressive force of the plant needs to be considered, and concrete segments with excellent compression properties can be used, and if corrosion protection is complete, the lining metal layer can be thinner, among other advantages. In order to construct such an underground tank more economically and increase its structural strength, it is effective to use segments that can be obtained at relatively low cost, but the segments have a somewhat low compressive strength. However, this problem has to be overcome, and this problem must also be resolved at the same time.

5. Based on the above-mentioned viewpoints, the present invention provides a method for constructing an underground tank that can obtain a tank main body with extremely high compressive strength while using segments that can be obtained economically, and which provides a method for constructing an underground tank that can obtain a tank body with extremely high compressive strength while using segments that can be obtained economically. The sheath is embedded in the plant in advance, and pre-stressing is applied by tightening the adjacent segments with the tension of the steel wire inserted through the sheath at the appropriate time during the construction process 0, and the completed plant is completely finished. It is characterized by having extremely large internal stress in two directions: vertical and horizontal.

j5 Hereinafter, the present invention will be described by way of examples with reference to the accompanying drawings.

First, in carrying out the invention, a square tubular segment 1, shown in plan view in FIG. 1 and in side view in FIG. 2, is used.

The left and right end faces of the segments 1 are beveled so that when the segments 1 are arranged in an annular shape to obtain the desired diameter of the tank wall body 2 as shown in FIG. 3, adjacent segments can be brought into close contact with each other. Further, a large number of vertical sheaths 3 are embedded in rows along both longitudinal edges, and horizontal sheaths 4 are embedded in the front and rear walls in the above arrangement. The segments 1 are rectangular pipes in the shape of reinforced concrete blocks, and have a rectangular cross section (square in the illustrated example).The segments 1 are arranged in a ring shape as shown in FIG. horizontal sheath 4
Press dressing is applied by tightening the steel wire 5 inserted through the holder.

This pressing operation may be performed at any time after the arrangement of two or more pieces is completed. That is, the steel wires 5 may be tightened in batches of several pieces, and the steel wires 5 may be tightened by appropriately using metal fittings or welded to prevent loosening of the steel wires 5, or may be tightened after the steel wires 5 are arranged in an annular shape. The assembly of the second stage is carried out while the assembly of the first stage is in progress or after the assembly of the first stage is completed 6 In this case as well, the vertically adjacent parts are pressed together by the steel wire 6 inserted through the sheath 4. As with 5, the tensioned steel wire 6 is maintained in a tensioned state by appropriate means. After completing the assembly of the required number of stages or all stages as described above, the earth and sand inside the ring is excavated and the whole is gradually settled.

After it has been sunk to the required depth, construction is carried out according to conventional methods, including the installation of a metal lining and membrane. The construction is completed by providing a roof (not shown) on the layered wall body 2 constructed as described above and attaching incidental equipment.

As is clear from the above description, according to the present invention, regardless of whether or not the segment is made of PS concrete, the steel wire inserted through the sheath is press-dressed by applying a tensile force. Since each adjacent segment is clamped, the entire tank wall body 2 is clamped in two directions vertically and horizontally by steel wires, and is made of relatively inexpensive rectangular pipe-shaped segments made of reinforced concrete blocks, resulting in high strength. The result is a well-insulated underground tank, especially when the segments are left hollow.

In particular, according to the present invention, since the segment 1 has a rectangular tubular shape, it is extremely strong and lightweight, and since the segment 1 is formed with a rectangular cross section, the second stage is placed on top of the first stage. When the eyes are placed and assembled, the area of the upper and lower parts that make surface contact with each other is wide and easy to place, and these factors make it extremely easy to assemble on site. Further, in the tank wall body 2 constructed using the rectangular tubular segments 1, cavities continuous in the circumferential direction are sequentially formed at intervals in the height direction of the tank wall body 2, and each of these cavities is Both have independent configurations. Therefore, not only is heat insulation achieved by the air inside each cavity, but there is no vertical convection, so even if the tank wall body 2 is partially heated or cooled, it is not transmitted to the whole. Therefore, it is particularly suitable as an underground tank for liquid fuel, etc. Furthermore, at least 2
Since the steps are assembled and press-dressed vertically and horizontally before being submerged, the structure has sufficient resistance not only to radially inward earth pressure but also to vertical bending during submergence.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the segment used in carrying out the present invention, FIG. 2 is a side view of the segment shown in FIG. 1, and FIG. 3 is a plan view of the tank wall main body, partially omitted. FIG. 4 is an explanatory diagram of assembly. 1... Segment, 2... Tank wall body,
3, 4... Sheath, 5, 6... Steel wire.

Claims (1)

[Claims] 1 Rectangular tubular segments with a rectangular cross section in which sheaths are embedded vertically and horizontally are arranged horizontally in a ring, and prestressed by the tension of a steel wire inserted through the transverse sheath of each adjacent rectangular tubular segment to integrate them. Assemble the first stage, which is a part of the main body of the tank wall to be constructed, and then place segments similar to the above segments on top of this first stage and arrange them in a ring, and then sheath each adjacent segment in the lateral direction. The tension of the steel wire passing through the segments applies prestress to assemble the second stage, and the tension of the steel wire passing through the longitudinal sheath of each segment of the second stage and the first stage. Then, the third and subsequent stages are assembled in the same manner as the second stage to construct the tank wall body, and after assembling at least the second stage, the ground is assembled using the well construction method. An underground tank construction method characterized by submerging the tank inside.