JPH0784809B2 - Construction method of circular underground tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a method for constructing a circular underground tank used for storing petroleum, LNG and the like.

[Prior Art and Problems to be Solved by the Invention]

Conventionally, as a construction method of this type of tank, an outer mold and an inner mold are respectively provided at the time of forming the peripheral side wall, and concrete is placed between the outer mold and the inner mold to form the tank. Those forming side walls are generally known.

However, it is difficult for the outer mold and the inner mold to stand by themselves because the excessive pressure of the cast concrete is applied to them. Therefore, it is necessary to support the lateral pressure of the cast concrete by connecting the inner and outer molds with a separator.

As described above, in the conventional construction method, it is necessary to provide the inner and outer molds and connect the inner and outer molds with the separator, which makes the construction work troublesome and time-consuming.

The present invention has been made to solve the above problems, and an object thereof is to provide a construction method capable of easily constructing a circular underground tank in a short time.

[Means for Solving the Problems]

This invention cures the surrounding rock wall surface after excavation of the tank construction part, uses the cured wall surface as an outer mold, and uses a large number of segments incorporated along the rock wall surface as an inner mold, This is a construction method of a circular underground tank consisting of placing concrete concrete between the outer and inner molds, in which the incorporation of each segment used as the inner mold is prescribed along the ground wall surface. It is supported by fixed columns that are erected at intervals, and at the top of each segment that becomes the inner formwork, keep each segment in a circular shape, and temporarily install a retaining ring member that serves as a scaffolding for pouring concrete concrete. It is characterized by placing concrete.

〔Example〕

The underground tank construction method of the present invention will be described below with reference to illustrated embodiments.

The circular underground tank 1 (see FIGS. 2 and 3) of the present invention includes a circular peripheral side wall 2, a bottom plate 3, and a pumping pipe 4.
And a roof 5.

The circular underground tank 1 having such a structure is shown in FIG.
It is constructed by the process shown in FIG.

First, an underground wall 6 or the like is provided as an earth retaining work in the area of the upper soft ground, and the ground of the tank construction portion is excavated. Then, the surrounding rock wall surface in the lower rock portion is cured by the NATM method as shown in FIG. 1, that is, the lock bolt 7 is arranged, the sheet 8 to be the mold surface and the pad for this sheet are also used. Outer formwork by laying and spraying the drain material 9
A peripheral side wall 2 to be 12 is constructed (see FIGS. 4 and 5).

In FIG. 1, reference numeral 16 is a reinforcing bar.

Next, the lower end of the peripheral side wall 2 and the bottom slab 3 are manufactured (6th
(See Figures and 7).

The segment 10 made of RC or the like is used for the inner mold 11, and the inner mold 11 is constructed by incorporating this, and the curing portion of the surrounding natural wall surface that is cured by the NATM method as described above is used as the outer mold 12.
A concrete frame 13 is placed between the inner mold 12 and the outer mold 12 (see FIG. 8).

In addition, the installation of each segment 10 here is shown in Figs.
As shown in Fig. 13, the fixed column 14 is embedded in the skeleton concrete 13 by dividing the inner circumference of the tank into several parts, the segment ends are fixed to this fixed column 14, and each segment 10 is applied to the excessive lateral pressure of the cast concrete 13. It is designed so that it can be designed as a circular fixed arch that can withstand.

Each segment is connected with a bolt.

Further, since the inner formwork needs to have a sufficiently finished shape as the finishing accuracy of the tank, the deformation amount must be kept within the control value, and the deformation preventing retaining ring member 15 that can be detachably attached to the top of each segment 10 Install. The retaining ring member 15 for preventing deformation can also be used as a work floor for pouring concrete.

Next, concrete is placed between the inner mold 11 and the outer mold 12. When the skeleton concrete 13 is solidified and the circular side wall 2 is completed, the roof 5 is manufactured and the interior work is performed.
See figure).

Finally, embankment and auxiliary work are performed to complete the construction of the circular underground tank 1 (see Fig. 10).

〔The invention's effect〕

According to the present invention, which has the above-described structure, and the cured wall surface is used as the outer mold according to this construction method, it is not necessary to separately provide a dedicated outer mold. Therefore, it is possible to shorten the construction time of the entire circular underground tank because the outer mold is not required to be formed.

Further, the segments of the inner formwork connect adjacent segments to each other with bolts or the like, but the lateral pressure of the cast concrete can be supported by an arch action due to the circular tank. Therefore, conventionally, the outer form and the inner form were connected by the separator to support the lateral pressure of the cast concrete, but this separator can be eliminated.

Further, by attaching the retaining ring member to the upper end of the segment which is the inner mold, it is possible to keep the amount of deformation of the inner mold within the control value because it is necessary to have a finished shape that is sufficient for the finishing accuracy of the tank. Moreover, since this retaining ring member can be used as a work floor for concrete pouring,
The concrete pouring work can be performed easily.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a circular peripheral wall portion formed by the construction method for a circular underground tank according to the present invention.
FIG. 4 is a plan view of a circular underground tank formed by the construction method of the present invention, FIG. 3 is a sectional view taken along line AA of FIG. 2, and FIG.
Fig. To Fig. 10 are construction process diagrams of a circular underground tank by the construction method of the present invention, Fig. 11 is a cross-sectional view of the circular underground tank showing the assembled state using fixed columns of each segment,
12 is an enlarged sectional view of a B portion in FIG. 11, and FIG. 13 is an enlarged perspective view of a B portion in FIG. 1 ... Circular underground tank, 2 ... Surrounding side wall, 3 ... Bottom plate,
4 ... Pumping pipe, 5 ... Roof, 6 ... Underground wall, 7 ... Rock bolt, 8 ... Sheet, 9 ... Drain material, 10 ... Segment, 11 ... Inner formwork, 12 ... Outer formwork, 13 …… Frame concrete, 14 …… Fixed column, 15 …… Holding ring member, 16
…… Reinforcing bar.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsuhiro Fukada 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (56) Reference JP-A-54-118634 (JP, A)

Claims (1)

[Claims] 1. A surface of a rock mass around the ground after excavation of a tank construction part is cured, the cured wall is used as an outer mold, and a large number of segments incorporated along the ground wall are used as an inner mold. This is a construction method of a circular underground tank consisting of placing structural concrete between the outer formwork and the inner formwork, and incorporating each segment used as the inner formwork along the ground wall surface. It is supported by fixed columns that are erected at regular intervals, and at the upper end of each segment that forms the inner formwork, each segment is kept circular and a retaining ring member that serves as a scaffold for the construction work of skeleton concrete is temporarily installed. A construction method for a circular underground tank, which is characterized by performing concrete pouring.