JP3748615B2 - Construction method of cylindrical underground structure - Google Patents

Description

また、水没外溝３０の底部に形成されたコンクリート栓３１は、着底させた円筒状コンクリート函２１の下方に水没立坑１０内の充填水や重泥水３３が廻り込むのを防止して、内部の注水を排出する際に、円筒状地中構造物２０が浮力により浮上するのを防止する。
【００５３】
さらに、ベントナイトを注入して水没外溝３０の下部に形成されたベントナイトパッカー３２は、これのゲル強度の発揮により、図９に示すように、連続地中壁の下部における側圧力を静水圧相当のものに維持する（図９（ａ）はベントナイトパッカーを形成しない場合、（ｂ）はベントナイトパッカーを形成した場合のゲル圧の鉛直方向の変化状況を示すものである。）。
【００５４】
さらにまた、水没立坑１０の底部に着底させた、円筒状地中構造物２０を構成する円筒状コンクリート函２１の床版コンクリート２３には、排水孔２８を設け、円筒状コンクリート函２１内への地下水の流入を可能にすることによっても、地下水圧の逃げ道を確保して円筒状地中構造物２０が浮力により浮上するのを容易に防止することができる。
【００５５】
なお、かかる排水孔２８は、例えば、床版コンクリート２３を打設形成する際に、開閉可能な水抜きパイプ等を埋め込んでおけば、円筒状コンクリート函２１の着底後にこれを解放することによって容易に設けることができる。
【００５６】
そして、水没外溝３０を重泥水３３で充填したら、円筒状地中構造物２０の内部に投入した注水を送水管３５を介して適宜排出するとともに、円筒状地中構造物２０の上端外周に耐震用の支承版３６を取り付ける作業等、その他の付属作業を行って、円筒状地中構造物２０によって構成される、図１０に示すような気密性に富んだＣＡＥＳタンク５０の構築作業が終了する。
【００５７】
このようにして構築されたＣＡＥＳタンク５０は、夜間の余剰電力等を圧縮空気として貯蔵するための貯蔵空間５１を有するとともに、上部に下水処理のための汚泥消化槽５２を備え、夜間電力を有効利用しつつ下水の処理を行なう機能を備えるものである。
【００５８】
なお、この実施例では、地中にＣＡＥＳタンク５０を構築する際にこの発明を適用する場合について記載したが、この発明は上記実施例の態様のものに限定されるものではなく、地下空間を設けるための種々の地中構造物を構築すべく採用することができる。
【００５９】
【発明の効果】
以上詳細に説明したように、この発明の円筒状地中構造物の構築方法によれば、水没立坑の開口部に底面が閉塞された円筒状の函体を形成し、この函体の側壁部分を、外型枠と内型枠とを上下方向にスライドさせながら、内側型膜及び外側型膜を順次上方に継ぎ足し、外型枠と内型枠との間に順次コンクリートを打設することにより、上方に継ぎ足していく工程と、函体の内部に順次注水しながら、函体を水没立坑内に徐々に沈設させてゆく工程とを繰り返すことにより、水没立坑内に大規模、大深度の円筒状地中構造物を構築することができる。
従って、鉛直方向に継目が介するようなことがない気密性、水密性に優れた円筒状地中構造物を構築することができる。さらに、円筒状地中構造物の側壁部分の内周部及び外周部には全体に亘って内側型膜及び外側型膜が配置されることになるので、側壁部分の強度を高めることができる。
【００６０】
また、水没立坑の底部に着底させた円筒状地中構造物と水没立坑の内壁面との間の水没外溝に重泥水を充填することにより、重泥水による大きな重泥水圧によって円筒状地中構造物が内方に押圧され、円筒状地中構造物の周方向に圧縮力、すなわちプレストレスを付加することができるので、円筒状地中構造物を、内部に貯留した加圧物質の内圧にも耐え得る強固な構造とすることができる。
【図面の簡単な説明】
【図１】水没立坑を、所定の深度まで掘削形成する工程を示す説明図である。
【図２】水没立坑内にケーシング幕を設置する状況を示す説明図である。
【図３】水没立坑の開口部に、筒状地中構造物の底版部分を構成する、底面が閉塞する円筒状の函体を設置する状況を示す説明図である。
【図４】（ａ）〜（ｄ）は、水没立坑の開口部に函体を設置するための作業工程の一例を示す説明図である。
【図５】函体の側壁部分の上方に函壁を継ぎ足しながら、円筒状コンクリート函を水没立坑内に沈設してゆく工程を示す説明図である。
【図６】函体の側壁部分の上方に函壁を継ぎ足しながら、円筒状コンクリート函を水没立坑内に沈設してゆく工程を示す説明図である。
【図７】円筒状コンクリート函を水没立坑の底面に着底させた状況を示す説明図である。
【図８】着底させた円筒状コンクリート函と水没立坑の内壁面との間の水没外溝に重泥水が充填する状況を示す説明図である。
【図９】（ａ）及び（ｂ）は、ベントナイトパッカーを形成しない場合と形成した場合のゲル圧の鉛直方向の変化状況を示すチャートである。
【図１０】この発明の一実施例にかかる円筒状地中構造物の構築方法により形成されたＣＡＥＳタンクの構成を示す説明図である。
【符号の説明】
１０ 水没立坑
１１ 地中連続壁
１３ ケーシング幕
１５ 外型枠
１６ 床板
１７ 内型枠
１８ 外側型幕
１９ 内側型幕
２０ 円筒状地中構造物
２１ 円筒状コンクリート函
２２ 函体
２３ 床版コンクリート
２４ 側壁部分
２５ 函壁コンクリート
２８ 排水孔
３０ 水没外溝
３１ コンクリート栓
３２ ベントナイトパッカー
３３ 重泥水
４０ 立坑掘削装置
５０ ＣＡＥＳタンク[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for constructing a cylindrical underground structure, and more particularly, to a method for constructing a cylindrical underground structure for constructing a large-scale and deep underground structure.
[0002]
[Prior art]
In order to make effective use of underground space, storage tanks for liquefied natural gas and liquefied petroleum gas, etc., pressurized air storage tanks for storing midnight surplus power as compressed air, sewage treatment facilities, nuclear facilities, etc. For the purpose of providing, various construction methods for constructing a structure having a large-scale space in a deep position in the ground have been developed.
[0003]
And as a construction method for constructing such a large underground structure, for example, after constructing an underground continuous wall from the ground surface to the deep part of the ground, and excavating the interior as a mountain wall, A method for constructing the main body portion of the underground structure in the excavated work space can be considered. In addition, since this underground continuous wall is a structure that is effective in supporting the earth pressure from the outer ground, it is particularly effective to construct a cylindrical structure of this structure. It is common to construct a cylindrical wall as the underground continuous wall.
[0004]
On the other hand, in order to construct such a cylindrical underground continuous wall, a longitudinal groove excavator having a strip-like or circular excavation cross-sectional shape is used, and a large number of vertical grooves are arranged around the cylindrical underground continuous wall. In general, a method of forming a cylindrical underground continuous wall by continuously connecting and consolidating concrete inside each longitudinal groove while continuously excavating and forming in a ring shape along the direction Has been.
[0005]
And in the construction method in which such vertical grooves are connected in a ring shape in the circumferential direction, it is necessary to construct a vertical seam portion between concrete cast in adjacent vertical grooves with high accuracy.
[0006]
[Problems to be solved by the invention]
However, especially when building a large and deep underground continuous wall, the length of excavation by the longitudinal groove excavator becomes long, so it is difficult to construct a vertical seam between adjacent longitudinal grooves with high accuracy. There is a problem that a gap is likely to occur at the joint portion, and such a vertical joint has a problem that cracks are likely to occur due to horizontal contraction when the placed concrete hardens.
[0007]
Therefore, the built underground continuous wall needs to be water-stopped at the time of excavation inside, and since it is not reliable for airtightness and watertightness in order to make the main body structure, underground tank In the case of using as a storage space, etc., it was necessary to construct a structure such as a secondary lining separately inside.
[0008]
In addition, when storing pressurized substances such as compressed air inside, the high tensile pressure causes a circumferential tensile load to be applied to the cylindrical structure, thereby opening the seam and storing the pressurized substance. There was a problem that would be leaked to the outside.
[0009]
Therefore, the present invention has been made paying attention to these problems, and it is possible to easily construct and install a cylindrical underground structure rich in airtightness and watertightness even in deep underground. It aims at providing the construction method of a cylindrical underground structure.
[0010]
Further, the present invention provides a cylindrical underground structure for obtaining a structure capable of storing a pressurized material in a stable state against such pressure even when the pressurized material is stored therein. The purpose is to provide a construction method.
[0011]
[Means for Solving the Problems]
The present invention has been made in order to achieve the above object, and the gist thereof is that a submerged shaft having a cross-sectional shape capable of accommodating a large-scale and deep cylindrical underground structure to be constructed has a predetermined depth. A cylindrical outer formwork is slidable in the vertical direction at the opening of the submerged shaft and installed in a suspended state, and a bottom plate is installed at the lower end of the outer formwork Then, by placing concrete on the top of the bottom plate, a step of forming the bottom slab concrete of the cylindrical box with the bottom closed, and on the inner peripheral surface of the outer mold frame on the top of the bottom slab concrete The cylindrical inner mold is opposed to be slidable in the vertical direction, and is installed in a suspended state, and an outer mold film is disposed along the inner circumferential surface of the outer mold, and the outer circumference of the inner mold is Install the inner mold membrane along the surface, By pouring concrete between the inner mold, a step of forming a side wall of the inner membrane and a box body, wherein the outer membrane is disposed on the inner peripheral portion, the outer frame and in the Slide the mold up and down, and while adding the inner mold film and the outer mold film, put concrete between the outer mold frame and the inner mold frame, the side wall portion of the box upward A step of sequentially adding water , a step of sequentially pouring water into the box, and gradually sinking the box into a submerged shaft, a step of sequentially adding side walls of the box, The inner mold film and the outer mold film are arranged on the inner and outer peripheral portions in the submerged shaft by repeating the process of sequentially injecting water into the box and sequentially depositing the box in the submerged shaft. cylindrical underground structure, characterized in that to construct a cylindrical underground structure A strategy for a thing.
[0012]
That is, while sliding the outer mold frame and the inner mold frame installed in the opening of the submerged shaft in the vertical direction, the inner mold film and the outer mold film are sequentially added upward, and between the outer mold frame and the inner mold frame. Submerged by repeating the steps of placing concrete sequentially, adding the side walls of the box sequentially upward, and sequentially pouring water into the box and then sinking the box into the submerged shaft. A cylindrical underground structure in which the inner die membrane and the outer die membrane are disposed on the inner and outer peripheral portions can be constructed in the shaft .
[0014]
According to the construction method of the cylindrical underground structure of the present invention, heavy mud water is placed in the submerged outer groove between the cylindrical underground structure grounded at the bottom of the submerged shaft and the inner wall surface of the submerged shaft. Is preferably filled.
[0015]
Further, a bentonite layer can be provided below the submerged outer groove so as to be interposed below the heavy mud water.
[0016]
Further, a concrete plug can be formed at the bottom of the submerged outer groove by pressing and solidifying the concrete so as to be interposed below the heavy mud water or the bentonite layer.
[0017]
Furthermore, it is also possible to allow the inflow of groundwater into the interior of the bottom plate portion provided drainage holes, cylindrical underground structure of the cylindrical underground structure was bottom landing to the bottom of the submerged pit.
[0018]
Also, the construction method of the cylindrical underground structure of the present invention is formed after the end of the step of excavating and forming the water submerged shaft having a cross-sectional shape capable of accommodating the cylindrical underground structure to be constructed to a predetermined depth. The submerged shaft can include a step of installing a cylindrical casing film covering the inner peripheral surface thereof.
[0019]
And according to the construction method of the cylindrical underground structure of the present invention, the cylindrical concrete box constituting the cylindrical underground structure is a donut that is continuously integrated into a ring shape while pouring water into the inside thereof. As the concrete walls are constructed by laying up and forming the walls as if they were stacked one after the other, the cylindrical underground structure landing on the bottom of the submerged shaft is No joints will be present.
[0020]
In order to form a box wall, the horizontal seam generated when the concrete is piled upward in a state of continuous integration in a ring shape is the latency of the upper end surface for each seam. Adhesion is easily maintained by placing the concrete while removing etc., or by being pressed by the weight of the box that is formed further above this, airtightness, It will be watertight.
[0021]
In addition, by filling heavy submersible water in the outer submerged groove between the cylindrical underground structure landing on the bottom of the submerged shaft and the inner wall surface of the submerged shaft, the cylindrical ground is generated by the heavy heavy mud pressure from the heavy mud. The intermediate structure is pressed inward, and a compressive force, that is, prestress, is applied in the circumferential direction of the structure, so that the cylindrical underground structure is made of the pressurized material stored inside. It has a strong structure that can withstand internal pressure.
[0022]
Furthermore, if a bentonite layer is provided at the lower part of the submerged outer groove so as to intervene below the heavy mud water, and a bentonite packer is formed, the gel underground structure exhibits a cylindrical structure. The side pressure at the lower part of can be maintained at a level equivalent to hydrostatic pressure.
[0023]
On the other hand, the cylindrical underground structure installed and submerged in the submerged shaft in this way, when draining the water injected inside to store the stored matter, it will try to float by buoyancy, The bottom of the submerged outer groove is interposed below heavy mud water or bentonite layer, and concrete is pressed and solidified to form a concrete plug, thereby forming a bottomed cylindrical underground structure. It is possible to prevent water in the submerged vertical shaft, heavy mud water, and the like from moving downward, and to easily prevent the cylindrical underground structure from rising due to buoyancy.
[0024]
In addition, a drainage hole should be provided in the bottom slab part of the cylindrical underground structure that is attached to the bottom of the submerged shaft, and groundwater can flow into the cylindrical underground structure through this drainage hole. Thus, a groundwater pressure escape path can be ensured, so that the cylindrical underground structure can be prevented from rising due to buoyancy.
[0025]
In addition, after completion | finish of the process which excavates and forms the water-immersed shaft of the cross-sectional shape which can accommodate the said cylindrical underground structure which should be constructed | assembled to the predetermined depth, the formed water-immersed shaft has a cylinder covering the inner peripheral surface thereof. If a submerged casing membrane is installed, the submerged shaft will be submerged even if a submerged shaft is provided on the ground that is prone to collapse, or even if the geology of the ground around the submerged shaft is not uniform and includes a ground that tends to collapse. The construction work of the cylindrical underground structure can be easily performed while protecting the wall surface of the shaft and without dissipating the muddy water in the submerged shaft to the surrounding ground.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Next, a preferred embodiment of the present invention, that is, an example, will be described in detail with reference to the accompanying drawings. The construction method of the cylindrical underground structure according to this embodiment shown in FIGS. 1 to 8 is a storage space for storing, for example, surplus power at night as compressed air at a depth of about 200 m to 360 m in the ground. 51 and a sludge digestion tank 52 for sewage treatment at the top, a so-called CAES (Compressed Air Energy Storage) tank 50 having a diameter of about 11 m and having a diameter of about 11 m is formed in the ground. (See FIG. 10).
[0027]
And according to the construction method of the cylindrical underground structure of this embodiment, first, as shown in FIG. 1, a cylindrical underground structure 20 having a diameter of about 11 m to be constructed is accommodated. The submerged shaft 10 filled with a filling water such as muddy water is excavated and formed to have a cross-sectional shape to be obtained, that is, a circular cross-section having a diameter of about 12 m and a depth of about 370 m in the ground. Prior to the excavation work, the underground continuous wall 11 having a depth of about 50 m is constructed on the ground around the submerged shaft 10 around the periphery of the opening.
[0028]
This excavation work can be performed using, for example, the shaft excavator 40 shown in FIG. 1. The gripper 41 is pressed against the inner wall surface of the submerged vertical shaft 10 to remove excavation reaction force, and the water submerged vertical shaft 10 is filled with water. The shaft 10 can be easily excavated and formed downward in the vertical direction by cutting the ground on the bottom surface with the cutter device 42 at the tip while satisfying the above and preventing the wall from collapsing.
[0029]
Such excavation work can be performed by using various well-known excavating machines in addition to the above-mentioned shaft excavating device 40, and the opening of the submerged vertical shaft 10 is protected by the inner wall surface covered by the underground continuous wall 11. Thus, excavation work and other work can be performed quickly without causing the ground of the opening to collapse.
[0030]
Then, when the excavation work of the submerged shaft 10 is completed, next, as shown in FIG. 2, a cylindrical casing curtain 13 made of, for example, a thin steel plate or a reinforced synthetic resin curtain is slightly smaller than about 12 m in diameter. The inner wall surface of the submerged shaft 10 is covered and installed, and the gap between the outer wall of the submerged shaft 10 is filled with a back-filling material 43 such as grout mortar.
[0031]
That is, the casing curtain 13 is used for the inner wall surface of the submerged shaft 10 when performing the operation of sinking the cylindrical concrete box 21 constituting the cylindrical underground structure 20 while placing concrete as will be described later. In addition to protecting this for a long period of time so as not to collapse, heavy muddy water is filled in the submerged outer trench 30 outside the cylindrical underground structure 20 that is filled in the submerged shaft 10 or on the bottom surface of the submerged shaft 10. When filling 33, these filling water and heavy mud water 33 are made not to dissipate in the surrounding ground. Further, the filling and filling operation of the backing material 43 around the installed casing curtain 13 can be easily performed, for example, via a tremi pipe or the like attached to the outer periphery of the casing curtain 13 when it is set. .
[0032]
The casing curtain 13 is not necessarily installed when the ground where the submerged shaft 10 is provided is a stable ground, or when the ground where the filling water and heavy mud water 33 are not dissipated.
[0033]
When the operation of excavating and forming the submerged shaft 10 and installing the casing curtain 13 as necessary is completed, next, as shown in FIG. An operation of installing a cylindrical box 22 constituting the bottom plate portion of the structure 20 and having a closed bottom surface is performed. The box 22 is manufactured according to the following process, for example, as shown in FIG.
[0034]
That is, first, a double-structured cylindrical outer frame 15 made of a slide form that is slidable in the vertical direction is provided on, for example, the ground along the inner peripheral surface of the opening of the submerged shaft 10 where the casing curtain 13 is installed. The floor plate 16 made of, for example, a steel plate, which is a bottom frame for constructing the box 22, is supported by a crane or the like, and the lower end of the outer mold frame 15 passes through the inside of the outer mold frame 15. The work of hanging and supporting so as to be located at the part is performed (see (a)).
[0035]
Next, the work of forming the floor slab concrete 23 of the box 22 is performed by pouring underwater concrete from the ground above the installed floor board 16 (see (b)).
[0036]
When the floor slab concrete 23 is cast and formed, the floor slab concrete 23 is suspended and lowered until the top end surface of the floor slab concrete 23 is located at the lower end portion of the outer mold 15, and the box 22 is placed above the floor slab concrete 23. The outer mold film 18, the inner mold film 19, and the inner mold frame 17 are attached in order to cast the side wall portion 24 (see (c)).
[0037]
Here, the outer mold film 18 and the inner mold film 19 are formed in a cylindrical shape by, for example, a curtain member made of carbon fiber that is flexible and has a desired tensile strength, a synthetic resin curtain, a thin steel foil, a shape memory alloy foil, or the like. Therefore, it is integrally installed with the floor slab concrete 23 through various mounting members embedded in the floor slab concrete 23 in advance, and is sequentially installed upward. The outer mold film 18 and the inner mold film 19 can be integrated with the floor slab concrete 23 by embedding the lower end portion of the floor slab concrete 23 in the concrete.
[0038]
The outer mold film 18 is disposed along the inner peripheral surface of the outer mold frame 15, and the inner mold film 19 is disposed along the outer peripheral surface of the inner mold frame 17. Between the film 18 and the inner mold film 19, a space for placing a ring-shaped concrete having a predetermined width formed by the outer mold frame 15 and the inner mold frame 17 is held.
[0039]
Further, like the outer mold 15, the inner mold 17 is composed of a double-structured slide form that can slide in the vertical direction, and the wall of the side wall portion 24 of the box 22 between the outer mold 15 and the inner mold 17. It is installed in a state of being supported by a crane or the like provided on the ground and concentrically with the outer mold 15 with a thickness interval.
[0040]
When the outer mold film 18 and the inner mold film 19 and the inner mold frame 17 are attached, the concrete is placed in the ring-shaped concrete placement space formed between the outer mold film 18 and the inner mold film 19. While laying and solidifying in a state of being integrated in the circumferential direction without providing a vertical seam (see (d)), the side wall portion 24 of the box 22 is continuously built up and floor slab concrete is constructed. 23 is gradually lowered, and for example, the side wall portion 24 is raised until the box 22 composed of the floor slab concrete 23 and the side wall portion 24 floats (see FIG. 3).
[0041]
In addition, since the outer mold 15 and the inner mold 17 are configured as a slide structure having a double structure, as shown in FIG. The upper stage, that is, the side wall portion 24 of the second rod is transferred to the upper part of the molds 15 and 17 while the lower stage, that is, the first rod concrete is cured by sliding downward. it can.
[0042]
Then, when the cylindrical box 22 is installed in a suspended state or in a suspended state at the opening of the submerged shaft 10, in this way, as shown in FIGS. The inner mold membrane 19 is successively added and extended upward, and inside the outer mold frame 15 and the inner mold frame 17, a box wall concrete 25 is placed above the side wall portion 24 of the box body 22, and the upper mold film 19 is cured and cured. I will succeed. Further, in parallel with the joining work, the work of laying the constructed cylindrical concrete box 21 in the submerged shaft 10 is repeated, and finally, as shown in FIG. 21 is settled on the bottom surface of the submerged shaft 10. In addition, in order to allow the cylindrical concrete box 21 to settle quickly in order, water is poured into the concrete box 21 to resist buoyancy applied to the concrete box 21.
[0043]
Further, in the above-described upward joining operation, the box wall concrete 25 of the cylindrical concrete box 21 has a predetermined rod length set according to the height of the outer mold frame 15 and the inner mold frame 17, and has a ring-like shape. The horizontal seam for connecting each rod upward is removed by removing the latency of the upper end surface of each rod, and the connecting part. It is possible to perform the work reliably and accurately, for example, by appropriately applying an incision bar.
[0044]
In addition, when, for example, slab concrete 26 or the like as an internal structure is constructed and formed inside the box wall concrete 25 to be constructed, for example, immediately below the outer mold frame 15 and the inner mold frame 17, for example, a box wall It can be easily constructed by providing a formwork through an anchor or the like driven into the concrete 25 and throwing the underwater concrete into the formwork attached in the vicinity of the opening of the submerged shaft 10.
[0045]
Moreover, it is preferable to use the outer mold film 18 and the inner mold film 19 that have been subjected to treatment such as airtightness, corrosion resistance, or microbial adhesion.
[0046]
If the cylindrical cylindrical concrete box 21 is settled on the bottom surface of the water submerged shaft 10 to form the cylindrical underground structure 20, the outer peripheral surface of the cylindrical concrete box 21 and the inside of the water submerged shaft 10 as shown in FIG. An operation of replacing the filled water in the submerged outer groove 30 formed between the wall surface, that is, the casing curtain 13 with the heavy mud water 33 is performed.
[0047]
In order to perform this operation, first, a concrete plug 31 is formed at the bottom of the submerged outer groove 30 by inserting a press-fit pipe into the submerged outer groove 30 to press-fit and solidify the underwater concrete.
[0048]
Also, bentonite packer 32 is formed below the submerged outer groove 30 by feeding bentonite water and providing a bentonite layer above the concrete plug 31.
[0049]
Then, the heavy mud water 33 is fed above the bentonite packer 32 and the heavy mud water 33 is replaced with the filling water in the submerged outer groove 30.
[0050]
Here, the heavy mud water 33 is defined as a liquid having a specific gravity substantially equal to or smaller than the unit volume weight of the surrounding natural ground, and the principle of Pascal as a fluid at room temperature or the temperature range of the stored material in the tank 50 is used. Preferably, it is composed of stable components that do not settle for a long period of time and do not decay, and specifically, for example, water, bentonite, a synthesized dispersant, barite fine powder, etc. are used in combination. be able to.
[0051]
In this embodiment, more specifically, a material having a specific gravity of 2.00 having the composition shown in Table 1 is used, and prestress is introduced into the cylindrical underground structure 20 by the heavy mud water 33. Thus, the cylindrical underground structure 20 has a strong structure that can withstand pressure from the inside.
[0052]
[Table 1]

Moreover, the concrete plug 31 formed at the bottom of the submerged outer groove 30 prevents the filling water and heavy mud water 33 in the submerged shaft 10 from flowing around below the bottomed cylindrical concrete box 21, When the water injection is discharged, the cylindrical underground structure 20 is prevented from rising due to buoyancy.
[0053]
Further, the bentonite packer 32 formed under the submerged outer groove 30 by injecting bentonite exhibits the gel strength of the bentonite packer 32, as shown in FIG. 9, the side pressure at the lower part of the continuous underground wall is equivalent to the hydrostatic pressure. (FIG. 9A shows the change in the gel pressure in the vertical direction when the bentonite packer is formed, and FIG. 9B shows the change in the gel pressure when the bentonite packer is formed.)
[0054]
Furthermore, a drainage hole 28 is provided in the floor slab concrete 23 of the cylindrical concrete box 21 that constitutes the cylindrical underground structure 20, which is attached to the bottom of the submerged shaft 10, and enters the cylindrical concrete box 21. By allowing the groundwater to flow in, it is possible to easily prevent the underground underground structure 20 from rising due to buoyancy by securing a groundwater escape route.
[0055]
For example, when the floor slab concrete 23 is cast and formed, if the drainage pipe 28 is embedded with an openable / closable drain pipe or the like, the drain hole 28 is released after the cylindrical concrete box 21 is settled. It can be easily provided.
[0056]
When the submerged outer groove 30 is filled with the heavy mud water 33, the water injected into the cylindrical underground structure 20 is appropriately discharged through the water supply pipe 35, and at the outer periphery of the upper end of the cylindrical underground structure 20 The construction work of the highly airtight CAES tank 50 as shown in FIG. 10, which is constituted by the cylindrical underground structure 20, is completed by performing other auxiliary work such as the work of attaching the earthquake-resistant support plate 36. To do.
[0057]
The CAES tank 50 constructed in this way has a storage space 51 for storing surplus power at night as compressed air, and has a sludge digestion tank 52 for sewage treatment at the upper part to effectively use night power. It has a function to treat sewage while using it.
[0058]
In this embodiment, the case where the present invention is applied when the CAES tank 50 is constructed in the ground has been described. However, the present invention is not limited to the embodiment described above, and an underground space is provided. It can be employed to build various underground structures to provide.
[0059]
【The invention's effect】
As described in detail above, according to the method for constructing a cylindrical underground structure of the present invention, a cylindrical box having a bottom closed at the opening of a submerged shaft is formed, and a side wall portion of the box is formed. By sliding the outer mold frame and the inner mold frame in the vertical direction, the inner mold film and the outer mold film are sequentially added upward, and concrete is sequentially placed between the outer mold frame and the inner mold frame. A large-scale, deep cylinder inside the submerged shaft is repeated by repeating the process of adding upward and the step of gradually sinking the box into the submerged shaft while sequentially pouring water into the box. The underground structure can be constructed.
Therefore, it is possible to construct a cylindrical underground structure having excellent airtightness and watertightness that does not involve a seam in the vertical direction. Furthermore, since the inner mold membrane and the outer mold membrane are disposed over the entire inner circumference and outer circumference of the side wall portion of the cylindrical underground structure, the strength of the side wall portion can be increased.
[0060]
In addition, by filling heavy submersible water in the outer submerged groove between the cylindrical underground structure landing on the bottom of the submerged shaft and the inner wall surface of the submerged shaft, the cylindrical ground is generated by the heavy heavy mud pressure from the heavy mud. medium structure is pressed inward, compressive force in the circumferential direction of the cylindrical underground structure, i.e. as it can be added to prestress, cylindrical underground structure, and stored inside the pressurized substance it can be a rigid structure that can withstand the internal pressure.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a process of excavating and forming a submerged vertical shaft to a predetermined depth.
FIG. 2 is an explanatory view showing a situation in which a casing curtain is installed in a submerged vertical shaft.
FIG. 3 is an explanatory diagram showing a situation in which a cylindrical box having a closed bottom surface, which constitutes a bottom plate portion of a cylindrical underground structure, is installed at an opening of a water submerged shaft.
FIGS. 4A to 4D are explanatory views showing an example of a work process for installing a box at the opening of a submerged shaft. FIG.
FIG. 5 is an explanatory view showing a process of sinking a cylindrical concrete box in a submerged shaft while adding the box wall above the side wall portion of the box.
FIG. 6 is an explanatory view showing a process of sinking a cylindrical concrete box in a submerged shaft while adding the box wall above the side wall portion of the box.
FIG. 7 is an explanatory view showing a situation in which a cylindrical concrete box is attached to the bottom surface of a submerged shaft.
FIG. 8 is an explanatory view showing a situation in which heavy muddy water is filled in a submerged outer groove between a bottomed cylindrical concrete box and an inner wall surface of a submerged vertical shaft.
FIGS. 9A and 9B are charts showing changes in the gel pressure in the vertical direction when the bentonite packer is not formed and when the bentonite packer is formed. FIGS.
FIG. 10 is an explanatory diagram showing a configuration of a CAES tank formed by a cylindrical underground structure building method according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Submerged shaft 11 Underground continuous wall 13 Casing curtain 15 Outer form frame 16 Floor board 17 Inner form frame 18 Outer form curtain 19 Inner form curtain 20 Cylindrical underground box 21 Cylindrical concrete box 22 Box 23 Floor slab concrete 24 Side wall Part 25 Box wall concrete 28 Drain hole 30 Submerged outer groove 31 Concrete plug 32 Bentonite packer 33 Heavy mud water 40 Vertical excavator 50 CAES tank

Claims (6)

A step of excavating and forming a submersible shaft having a cross-sectional shape capable of accommodating a large-scale and deep cylindrical underground structure to be constructed;
At the opening of the submerged shaft, a cylindrical outer mold is slidable in the vertical direction and installed in a suspended state, and a bottom plate is installed at the lower end of the outer mold, A step of forming a bottom slab concrete of a cylindrical box with a closed bottom by placing concrete ;
At the top of the bottom slab concrete, the cylindrical inner mold frame is slidable in the vertical direction so as to face the inner peripheral surface of the outer mold frame, and is installed in a suspended state, and the inner peripheral surface of the outer mold frame The outer mold membrane is arranged along the outer mold surface, the inner mold membrane is installed along the outer circumferential surface of the inner mold frame, and the concrete is placed between the outer mold frame and the inner mold frame, whereby the inner and outer circumferences are arranged. Forming a side wall portion of the box in which the inner mold film and the outer mold film are arranged in a part ;
The outer mold frame and the inner mold frame are slid vertically, and concrete is placed between the outer mold frame and the inner mold frame while adding the inner mold film and the outer mold film, and the box A process of sequentially adding the side wall portion of the body upward ,
Water is sequentially poured into the box, and the box is gradually submerged in a submerged shaft .
By repeating the step of sequentially adding the side wall portion of the box, and the step of sequentially pouring water into the box and sequentially sinking the box in a submerged shaft ,
A method for constructing a cylindrical underground structure, comprising constructing a cylindrical underground structure in which an inner mold membrane and an outer mold membrane are arranged on the inner and outer peripheries in the submerged shaft . 2. The submerged outer groove between the cylindrical underground structure grounded at the bottom of the submerged shaft and the inner wall surface of the submerged shaft is filled with heavy mud water. Construction method of cylindrical underground structure.   The method for constructing a cylindrical underground structure according to claim 2, wherein a bentonite layer is provided below the submerged outer groove so as to be interposed below the heavy mud water.   The concrete plug is formed at the bottom of the submerged outer groove by pressing and solidifying the concrete so as to be interposed below the heavy mud water or the bentonite layer. Construction method of cylindrical underground structure. The drainage hole is provided in the bottom slab portion of the cylindrical underground structure that is attached to the bottom of the submerged shaft, so that groundwater can flow into the cylindrical underground structure. 5. A method for constructing a cylindrical underground structure according to any one of 4 above. After completion of the step of excavating and forming a water submerged shaft with a cross-sectional shape capable of accommodating the cylindrical underground structure to be constructed to a predetermined depth, a cylindrical casing film covering the inner peripheral surface of the water submerged shaft is installed and installed. method for constructing a cylindrical underground structure according to any one of claims 1 to 5, characterized in that it comprises a step.

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