JPH06346621A - Roof construction method of underground tank - Google Patents

Abstract

PURPOSE:To reduce costs required for erecting a structure when a roof of a tank is constructed and shorten the whole construction period of a tank. CONSTITUTION:In a method for constructing a roof of an underground tank wherein the roof of the tank is constructed on the upper part of a side wall of a cylindrical body with bottom comprising a side wall and a bottom plate which is constructed in an excavated hole, after an earth retaining wall is erected, a primary excavated hole is bored at the upper part of the excavated hole. Next, a cylindrical structure 10 is constructed in the primary excavated hole to form the upper part of a side wall of the cylindrical body. Thereafter a support 9 is provided in the cylindrical structure 10. And a precast roof member is set on the upper steel frame 14 of the support to construct the roof of a tank.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roof construction method for a large underground tank in which low-temperature liquefied gas or the like is stored, and in particular, a tank roof and a bottomed cylindrical skeleton composed of side walls and bottom slabs are simultaneously constructed. Regarding how to do it.

[0002]

2. Description of the Related Art Conventionally, when constructing a large underground tank, first, after constructing a mountain retaining wall, a concrete bottom slab is placed in an excavation hole formed by excavating the ground in the mountain retaining wall.
A skeleton consisting of concrete side walls standing upright from the periphery of the bottom slab is constructed. When the skeleton is completed, many erection materials such as pipes and support materials are loaded into the skeleton, the erection materials are assembled, and a supporting structure (a erected structure) is erected inside the skeleton. This shoring has the same horizontal level as the upper end of the side wall, and while the roof member is supported by this shoring, the tank roof will be constructed so as to cover the upper opening of the side wall. .

[0003]

By the way, in the above-mentioned roof construction method for a large underground tank, an enormous amount of construction materials are required for constructing the support works, and when assembling or disassembling them. At that time, it took a lot of human labor and a lot of time, and there was a problem in terms of the cost of supporting construction.

Further, once the supporting work is installed inside the frame, it is not possible to perform other constructions inside the frame in parallel with the construction of the tank roof, and in the conventional tank roof construction method,
There was a problem that the construction period of the tank would be long.

The present invention has been made in view of the above circumstances, and it is possible to reduce the cost required for an erected structure when constructing a tank roof and to shorten the construction period of the entire tank construction. It is intended to provide a roof construction method for an underground tank.

[0006]

The method for constructing an underground tank roof according to the present invention is an underground construction in which a tank roof is constructed on the upper side wall of a bottomed cylindrical skeleton consisting of a side wall and a bottom slab to be installed inside an excavation hole. A method of constructing a roof for a tank, first, after constructing a mountain retaining wall, excavating a primary excavation hole in the upper part of the excavation hole, and constructing a tubular structure that becomes the upper part of the side wall of the body in the primary excavation hole. In this tubular structure, a lower steel frame horizontally arranged in the lower portion between the inner walls, an upper steel frame arranged in the upper portion between the inner walls, and a plurality of steel frames arranged between the steel frames. The bracing material is used to construct a support structure, and a precast roof member is constructed on the upper steel frame of the support structure to construct a tank roof.

[0007]

According to the method for constructing the roof of the underground tank of the present invention,
First, after constructing the mountain retaining wall, excavating the primary excavation hole above the excavation hole, and using the support work erected on the tubular structure that will be the upper side wall of the frame constructed in this primary excavation hole. It is possible to construct a tank roof with the construction of the tank roof, and in parallel with the construction of this tank roof, further excavate under the ground of the primary excavation hole and construct the entire side wall and bottom slab. It can be shortened.

Further, by utilizing the lower steel frame of the support work erected in the tubular structure as the traveling frame of the overhead crane, the work efficiency of tank construction is greatly improved.

Further, the supporting work is constituted by the lower steel frame, the upper steel frame, and the brace material, which are extremely small in number as compared with the conventional supporting work, and the supporting work is erected without much labor and time. be able to. Further, in the early stage of tank construction, if a tank roof composed of a plurality of roof members is constructed on the upper steel frame, rainwater will not enter the excavation hole even in bad weather.

[0010]

EXAMPLE An example of the method for constructing an underground tank according to the present invention will be described with reference to FIGS.

Reference numeral 1 shown in FIG. 3 is a cylindrical earth retaining wall embedded in the earth 2, and the earth 2 in the earth retaining wall 1 is excavated to a predetermined depth T1 to form an excavation hole 3 therein. There is.
The skeleton 5 of the underground tank 4 is built in the excavation hole 3. The skeleton 5 is a bottomed tubular structure including a tubular side wall 6 made of RC (reinforced concrete) and a bottom slab 7.

On the upper portion 8 of the side wall 6, a supporting work 9 is installed. The support structure 9 is supported between the inner walls of the tubular structure 10 and is also supported between the inner walls in the same manner as the lower steel frame 12 and the lower steel frame 12 arranged horizontally through the H-shaped steel 11. The upper steel frame 14 and the upper and lower steel frames 12, 1 having the same shape as the shape (dome shape) of the tank roof 13 to be constructed while
4 and a plurality of brace members 15 arranged between the four.

The upper steel frame 13 of the support structure 9
A plurality of plate-shaped roof members 16 having a reduced weight are erected on the top. The roof member 15 is made of lightweight concrete material, RC concrete, or the like, precast, and transported to the construction site. As a result, the upper opening 17 is closed and the tank roof 13 is constructed.

In this embodiment, the excavation hole 3 (depth T1) for burying the entire skeleton 5 is not excavated at the initial stage of tank construction, but as shown in FIG. In addition, a primary excavation hole of depth T2 (primary excavation hole depth T2 <excavation hole depth T1) 18 in which only the tubular structure 10 is embedded in the retaining wall 1 is characterized in that The cylindrical structure 10 is also composed of a concrete segment 10a which becomes the upper portion 8 of the side wall 6 of the body 5 to be finally formed. Then, the support structure 9 is installed inside the tubular structure 10. The tubular structure 10 embedded in the primary excavation hole 18 is supported by the ground 18 a of the primary excavation hole 18.

Next, a specific procedure of the method for constructing a tank according to the present invention will be described along with its operation. First, as shown in FIG. 1, after the earth retaining wall 1 is buried in the ground 2, the earth 2 inside the earth retaining wall 1 is excavated to form a primary excavation hole 18 of depth T2. Inside the primary drilling hole 18, the tubular structure 10 having a height substantially the same as the depth T2 of the primary drilling hole 18 is embedded. While being supported between the inner walls of the tubular structure 10, the H-shaped steel 1
The lower rebar frame 12 is arranged in the horizontal direction via the No. 1. Further, above the lower rebar frame 12, the upper steel frame 1 is supported via the H-shaped steel 11 while being supported between the inner walls.
Place 4 And the lower and upper steel frame 1
A plurality of brace members 15 are arranged between 2 and 14. As a result, the support structure 9 is installed inside the tubular structure 10. Here, the supporting structure 9 includes upper and lower steel frames 12 and 14 and the brace member 1 used in the conventional supporting structure.
Since the number of 5 etc. is extremely small, it can be installed easily in a short time. As shown in FIG. 2, the upper steel frame 14 of the shoring 9 is
A plurality of plate-shaped roof members 16 ... Are arranged on the top. As a result, the upper opening 17 of the tubular structure 10 is gradually closed, and the tank roof 13 is formed. Along with the construction of the tank roof 13, the ground 18a of the primary excavation hole 18 surrounded by the retaining wall 1 is further excavated, and the excavation hole is formed (the excavation hole that does not reach the depth T1 of the excavation hole 3). Then, along the inner surface of the retaining wall 1, the concrete segment 10a is constructed continuously with the tubular structure 10. In this case, the lower steel frame 12 extending in the horizontal direction of the supporting structure 9 is used as the traveling frame of the overhead crane, so that the work efficiency of constructing the skeleton 5 is significantly improved. Then, as shown in FIG. 3, the construction of the skeleton 5 is completed by providing the bottom plate 7 at the bottom of the excavation hole 3 which is finally excavated to the depth T1. Here, even after the construction of the underground tank 4 is completed, the supporting structure 9 is not disassembled as it is, and a roof structural member composed of the upper steel frame 14 of the supporting structure 9 and the roof member 16 can be obtained. As a result, a tank roof structure with increased rigidity can be obtained. On the other hand, when dismantling the support work 9 from the inside of the underground tank 4, a plurality of roof members 16 ...
By connecting while tensioning with a C steel wire or the like, the tank roof 13 having the same rigidity as the above can be obtained. In addition, the dismantling of the supporting structure 9 can be easily disassembled in a short time because the number of materials used is extremely small compared to the conventional supporting structure.

Therefore, according to the method for constructing the roof of the underground tank according to the present embodiment, after the earth retaining wall 1 is constructed, the tubular structure 10 is installed inside the primary excavation hole 18 excavated in the earth retaining wall 1, The tank roof 13 is constructed by using the supporting works 9 supported inside the tubular structure 10, and the ground 18 of the primary drilling hole 18 is formed in parallel with the construction of the tank roof 13.
Since the entire side wall 6 and the bottom slab 7 can be continuously constructed in the formed excavation hole 1 in the formed excavation hole 1 continuously with the cylindrical structure 10, the construction period of the underground tank construction can be greatly shortened. be able to.

Further, by utilizing the lower steel frame 12 of the support structure 9 installed in the tubular structure 10 as the traveling frame of the overhead crane, the work efficiency of tank construction can be greatly improved.

Further, the number of lower steel frames 12 and upper steel frames 13, which are extremely smaller than those of the conventional support work,
Since the support work is configured by the brace material 15 and the support work can be installed without requiring much labor and time, it is possible to reduce the cost required for the support work (building structure).

Further, in the early stage of tank construction, if the tank roof 13 composed of a plurality of roof members 16 is constructed on the upper steel frame 14, rainwater etc. will enter the inside of the excavation hole 3 even in bad weather. Therefore, the tank construction period can be further shortened.

When the roof members 16 are erected on the supporting work 9, the lower weight of the lower steel frame 1 due to an increase in the weight of the roof.
2 may have a vertical downward bend. In order to prevent the lower steel frame 12 from bending, the lower steel frame 12 may be formed in advance in a frame shape (a frame shape having a curvature upward in the vertical direction before a load is applied) in advance, or As shown in FIG. 3, the ring beam 20 is arranged on the upper periphery of the side wall, and a plurality of suspension cables 21 are stretched between the lower steel frame 12 and the ring beam 20. It is possible to prevent slump.

[0021]

As described above, in the underground tank roof construction method of the present invention, first, after constructing the retaining wall, the primary excavation hole above the excavation hole is excavated. While constructing the tank roof using the support work erected on the tubular structure that will be the upper side wall of the constructed frame, further excavation under the ground of the primary excavation hole will be performed in parallel with the construction of this tank roof. Since it is possible to construct the entire side wall and the bottom slab, it is possible to significantly reduce the construction period of the underground tank construction.

Further, the lower steel frame of the support work erected in the tubular structure can be used as the traveling frame of the overhead crane, whereby the work efficiency of the tank construction can be greatly improved.

Further, the supporting work is constituted by the lower steel frame, the upper steel frame, and the brace material, which are much smaller in number than the conventional supporting work, and the supporting work can be installed without much labor and time. Therefore, it is possible to reduce the cost for supporting work (construction structure).

Further, in the early stage of tank construction, if a tank roof composed of a plurality of roof members is constructed on the upper steel frame, rainwater will not enter inside the excavation hole even in bad weather, and the tank construction will be completed. The construction period can be further shortened.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which a support work is installed inside a primary excavation hole surrounded by a retaining wall in the present invention.

FIG. 2 is a cross-sectional view showing a state in which the tank roof is constructed in the present invention and the ground of the primary excavation hole is further excavated to form a skeleton.

FIG. 3 is a sectional view showing a final stage in which an underground tank is constructed in the present invention.

FIG. 4 is a sectional view of an essential part showing a structure for preventing the lower steel frame from bending in the present invention.

[Explanation of symbols]

 1 Earth retaining wall 2 Ground 3 Drilling hole 4 Underground tank 5 Body 6 Side wall 7 Bottom plate 8 Side wall upper part 9 Side support 10 Cylindrical structure 10a Concrete segment 12 Lower steel frame 13 Tank roof 14 Upper steel frame 15 Brace material 16 Roof member 18 Primary drilling hole 18a Ground of primary drilling hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 000206211 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Taisei Corporation (71) Applicant 000174943 Mitsui Construction Co., Ltd. 3--10-1, Iwamoto-cho, Chiyoda-ku, Tokyo No. (72) Koji Minegishi, Koji Minegishi 1-2-2, Ichikawa-shi, Chiba Sunny House Minami Gyotoku B-213 (72) Inventor Masafumi Nakano 3-3, Kamijijojo 3-chome, Kita-ku, Tokyo (72) Inventor Ken Shirasuna 2-3-3 Kandajimachi, Chiyoda-ku, Tokyo Within Obayashi Corporation (72) Inventor Hirofumi Yamashita 2-3, Kandajimachi, Chiyoda-ku, Tokyo Obayashi Corporation (72) Inventor Masamichi Yasunaga Minato-ku, Tokyo Moto Akasaka 1-27 Kashima Construction Co., Ltd. (72) Inventor Takeuchi et al. Moto Akasaka 1-3-8 Kashima Construction Co., Ltd. Tokyo Branch (72) Akito Kuroda Masanobu Kuroda 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Atsushi Sejima 1-2-3 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Masaaki Sakate 1-25-1 Nishishinjuku, Shinjuku-ku, Tokyo Inside Taisei Corporation (72) Inventor Mineo Kobayashi 1-25-1 Nishishinjuku, Shinjuku-ku, Tokyo Inside Taisei Corporation (72) Masatoshi Kato Tokyo 3-10-1 Iwamotocho, Chiyoda-ku Mitsui Construction Co., Ltd. (72) Inventor Muneki Watanabe 3-10-1 Iwamotocho, Chiyoda-ku, Tokyo Mitsui Construction Co., Ltd.

Claims (1)

[Claims] 1. A roof construction method for an underground tank, wherein a tank roof is constructed on a side wall upper part of a bottomed cylindrical skeleton composed of a side wall and a bottom slab constructed inside an excavation hole. After the construction, the primary excavation hole on the upper part of the excavation hole is excavated, and a cylindrical structure that is an upper part of the side wall of the body is constructed on the primary excavation hole. In the horizontal direction, the lower steel frame, the upper steel frame arranged in the upper part between the inner walls, and a plurality of brace members arranged between the steel frames are used to support the structure. A roof construction method for an underground tank, which comprises constructing a tank roof by erection of a precast roof member on the upper steel frame of the work.