JP4449532B2 - Rapid construction method of shaft by convex joint of deep bottom shaft - Google Patents

Description

   The present invention relates to a shaft construction method, and more particularly, to a key groove forming method at a bottom plate joining position of underground walls when a shaft is constructed, and a method for joining the underground wall and the bottom plate.

  Along with the concentration of urban functions, various facilities are installed in large cities on the ground and in the ground space, which is the center of people's lives. In addition, underground facilities have also been constructed for the development of social capital, such as underground shopping streets, subways, water supply and sewage systems, electricity, and gas. Therefore, the use of the ground, ground space, and shallow underground space has already been saturated, and the use of deep underground space, which was rarely used in the past, has been promoted for the regeneration and maintenance of urban functions. Yes.

  When constructing an underground structure in a deep underground space, it is necessary to secure a large space such as the start of a shield machine or a reaching shaft. When constructing a large space in the basement, for example, a circular underground wall is constructed in the ground, and the inside of the underground wall is excavated by taking measures against heaving, boiling, padding, etc. .

  In such construction, when the water surrounded by the underground wall is drained, lifting pressure acts on the bottom plate, so various methods have been adopted as a construction technology for the resisting. For example, an open pipe that is divided into several blocks, with a well without a lid or bottom, is divided into several blocks as an underground wall, the ground surrounded by the underground wall is excavated underwater, and subsidence and building of the chassis are repeated to a predetermined depth. The caisson method and the depth that balances the lifting pressure acting on the bottom of the impermeable layer and the weight of the mass from the bottom of the excavation to the impervious layer are improved, and the depth of the underground wall is deepened to the ground improved layer. An underground continuous wall excavation method for underwater excavation of the inner ground surrounded by underground walls.

  Both of the above methods involve excavation of the interior surrounded by the underground wall by underwater construction, and after excavation, such as underwater concrete and ground improvement to resist the lifting pressure on the inner bottom surface surrounded by the underground wall A temporary structure will be constructed to prevent the inflow of groundwater and dry up to install the bottom plate.

  And as a construction method of the bottom slab part, by forming a notch part that becomes a concave-convex joint in advance at the bottom plate joining position at the lower part of the underground wall, the concrete that becomes the bottom slab is then placed in water, so that the bottom slab concrete is There is a method of going around into the notch and integrating the underground wall and the bottom board by uneven connection. The following method has been proposed as a method of forming this notch.

  The notch forming means incorporated in the reinforcing bar built in the vertical groove constituting the underground wall is formed according to the notch shape of the joining position of the bottom plate, and the steel frame with the opening surface facing the bottom plate side, A biodegradable sheet that covers the opening surface of the steel frame, a biodegradable filler that holds the sheet in an expanded state on the opening surface of the steel frame by being filled inside the sheet, and a steel frame. It has an injection pipe that penetrates through and communicates its lower end with the interior of the sheet, and projects the upper end into the ground part. A rebar is built in the longitudinal groove, and a biodegradable filler is injected into the sheet. After the concrete surface is placed, and the concrete is hardened, the biodegradation agent is injected and filled into the inside of the sheet through the injection tube. A method of biodegrading and extinguishing and opening the opening surface of the steel frame to the outside is proposed And it has (see Patent Document 1).

  In addition, the following method has been proposed as a method of joining the underground wall and the bottom plate.

Reinforcement rod 2 with a jack in advance is built in the connecting position between the underground wall and the bottom slab in the reinforcing bar built in the vertical groove that constitutes the underground wall, and the reinforcing bar is placed on the side of the bottom slab of this reinforcing rod 2 Place and lock the concrete in the vertical groove of the underground wall and harden it. Then, after excavation of the inside of the underground wall, underwater concrete is placed on the bottom surface in the underground wall. After placing the underwater concrete, the jack is operated and the rebar protrudes toward the bottom plate. In this protruding state, the extension stroke of the jack is adjusted so that the rebar straddles between the underground wall and the underwater concrete. And the method of putting concrete in the clearance gap between underwater concrete and an underground wall, and joining underwater concrete and an underground wall is proposed (refer patent document 2).
JP2003-328377 JP 2000-336645 A

  However, in the open caisson method, when the shaft inner diameter is large or the shaft depth is deep, it is necessary to increase the thickness of the underwater concrete to resist the lifting pressure, and there is a problem in terms of construction period and cost.

In addition, the underground continuous wall excavation method has a problem that the ground improvement is often expensive, and the reliability of the improved body remains uneasy. When the depth of the underground wall was increased, the safety of excavation work increased, but there was a problem in terms of cost. In addition, both methods had a temporary structure that resisted the lifting pressure acting on the bottom plate. After construction (underwater concrete and ground improvement), the process from the completion of excavation to the construction of the bottom slab in order to dry up the shaft and construct the bottom slab is called construction of the temporary structure, dry up, construction of the bottom slab There are 3 steps, and there were problems in terms of construction period and cost.

  The method of forming a notch for the method of constructing the bottom plate and using the biodegradable sheet and the biodegradable gel is expensive in the biodegradable plastic itself, and the biodegradable sheet and the biodegradable gel Has a problem in cost because secondary processing is required. Furthermore, there is a problem that it takes time until the biodegradable plastic is decomposed.

  In addition, the method of joining the underground wall and the bottom slab with reinforced concrete using a jack is difficult to install the jack at the joint position of the underground wall and the bottom slab. However, there were problems such as requiring a large-scale device and burying and killing the jack.

  In addition, the development of deep underground spaces is expensive compared to the development of underground and shallow shallow underground spaces, but due to changes in the social situation in recent years, there is a strong demand for cost reductions in construction costs. It was necessary to build social capital at the lowest possible cost.

  Then, this invention is made | formed in view of the said problem, and makes it the main objective to provide the rapid construction method of the shaft which aims at construction period shortening and cost reduction.

The construction method of the shaft according to the present invention that solves the above problem is that a key groove is formed in advance at the coupling position with the bottom slab on the bottom side surface of the underground wall, and the underground wall and the bottom slab are jointed unevenly by this key groove . A construction method, which is formed according to the shape of the key groove at the bottom plate coupling position, the key groove forming body with the opening surface of the key groove facing the bottom plate side, and the key groove forming body is extruded to the bottom plate side. the keyway forming means comprising a pushing device, characterized in that provided in the longitudinal groove so as to constitute the diaphragm wall (first invention).

The construction method of the shaft of the second invention is the construction method of the first invention, in which the keyway forming means is provided in the longitudinal groove in order to form the underground wall, and the concrete is cast, and after the concrete is hardened, The ground surrounded by the underground wall is excavated, and after the excavation is completed, the pushing device is driven to push the key groove forming body to the bottom plate side to form a key groove.

The shaft construction method of the third invention is characterized in that, in the first or second invention, the key groove forming body has a specific gravity smaller than that of water.

Extrusion apparatus of the fourth invention, in any one of the first to 3, characterized by comprising a bag-shaped rubber expansion by injecting a liquid or gas.

The extrusion apparatus according to a fifth aspect of the present invention is characterized in that, in any one of the first to third aspects, the extrusion apparatus includes a jack that expands and contracts by injecting liquid or gas.

Construction method of the vertical shaft of the sixth aspect, in any one of the first to 5, in the inside of the bottom, surrounded by the ground wall, building a reinforced concrete underwater construction as the bottom plate, said key groove and the reinforced concrete The bottom plate and the underground wall are integrated with each other by filling the gap between them with unreinforced concrete and making the side section convex.

The construction method of the shaft according to the seventh invention is the construction method of any one of the first to sixth inventions, wherein the key groove forming body is in contact with the bottom slab-side ground and becomes an opening surface plate of the key groove, and the opening A top plate that is obliquely provided with a predetermined inclination angle with respect to the opening face plate at an upper portion of the face plate, and is provided with a predetermined inclination angle with respect to the opening face plate at a lower portion of the opening face plate. It consists of a bottom plate, a back plate parallel to the opening face plate and formed on the top plate and the bottom plate, and side plates covered on both sides of the opening face plate, and is formed in a keyway shape. It is characterized by that.

The shaft construction method of the eighth invention is the construction method of the bottom plate according to any one of the first to seventh inventions, from the completion of excavation of the ground surrounded by the underground wall to the construction of the shaft. It is characterized by being performed in order.

The structure of the shaft of the ninth invention is a shaft constructed in any one of the inventions of claims 1 to 8 , and is constructed by a continuous wall of the underground wall and formed on the bottom side surface of the underground wall A convex bottom plate is concavo-convexly connected to the key groove to be formed.

The shaft structure of the tenth invention is a structure constructed by any one of the methods of claims 1 to 8 , wherein the underground wall having the keyway on the bottom side surface and the convex bottom plate are connected by unevenness. It is characterized by.

  According to the present invention, a key groove is provided on the bottom side surface of the underground wall, the bottom plate is convex, and the underground wall and the bottom plate are integrated to resist the lifting pressure, and the depth of root removal of the underground wall is increased. Can be made shallower, and construction can be performed at a lower cost than the ground improvement method. In addition, underwater excavation does not affect the surrounding ground such as ground subsidence or groundwater level drop as in the conventional groundwater level lowering method. Furthermore, since the construction method of the shaft is changed from the conventional three-step construction of the temporary structure, dry-up, and bottom plate construction to two-step construction of the bottom plate and dry-up, the construction period can be shortened.

  In the future, if a system for the use of deep underground space is established, it is considered that the use of deep underground by business operators, etc. will be promoted. It becomes possible to provide this construction method so that it can construct safely.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1A is a perspective view of the key groove forming means according to the first embodiment of the present invention, FIG. As shown in FIG. 1A, the key groove forming means 1 is formed in accordance with the key groove shape at the bottom plate coupling position, and is arranged so that the opening surface serving as the opening of the key groove is in contact with the bottom plate side ground. keyway forming body 3 (cured material 4 is filled in.) that a is assembled to the reinforcement cage provided in the key groove formed body 3 have a recess for removably enclosing the longitudinal groove steel It is provided with a frame making 3A and an extrusion device 5 which is installed in the steel frame 3A and supplies the liquid or gas inside to swell to push the key groove forming body 3 to the bottom plate side.

  The extrusion device 5 is made of, for example, rubber, and when swollen, pushes the key groove forming body 3 to the bottom plate side through the insertion hole 3B formed in the steel frame 3A. In addition, the extrusion apparatus 5 may operate | move electrically or mechanically.

  The lower end of the injection pipe 6 communicates with the extrusion device 5, and the injection pipe 6 communicates with the liquid or gas supply means installed on the ground portion through the inside of the reinforcing bar.

  As shown in FIG. 1 (b), the key groove forming body 3 is in contact with the bottom plate side ground and the steel frame 3A, and has an opening surface plate 3a serving as an opening portion of the key groove, and an opening surface plate above the opening surface plate 3a. With respect to 3a, for example, a top plate 3b that is inclined with an inclination angle of about 20 to 60 degrees (60 degrees in this embodiment), and an opening surface plate 3a below the opening surface plate 3a. For example, the bottom plate 3c is inclined with an inclination angle of about 20 to 40 degrees (30 degrees in this embodiment), and is parallel to the opening face plate 3a and is formed into a top plate 3b and a bottom plate 3c. The back plate 3d is provided, and the two side plates 3e are provided so as to seal the key groove forming body 3 on both sides of the opening face plate 3a, and are formed in a key groove shape. Then, after the key groove forming body 3 is detached, the steel frame 3A becomes a key groove mold to be formed at a position where the steel frame 3A is coupled to the bottom plate on the bottom side surface of the underground wall.

  If the formation angle of the bottom plate side ground and the upper surface portion of the steel frame 3A (= opening face plate 3a and top plate 3b) exceeds 60 degrees, the concrete will be placed on the bottom plate side ground when placing concrete for underground walls. There is a possibility that the tangent line between the mountain and the upper surface portion of the steel frame 3A may not be sufficiently filled. There is a possibility that the top plate 3b and the upper surface portion of the steel frame 3A are caught by receiving upward buoyancy due to the influence of water existing inside. Therefore, the formation angle of the bottom plate side ground and the upper surface portion of the steel frame 3A (= the opening face plate 3a and the top plate 3b) is adjusted, the underground wall concrete is sufficiently filled, and the keyway is formed. The formation angle of the bottom plate side ground and the upper surface of the steel frame 3A (= opening face plate 3a and top plate 3b) is set to about 20 to 60 degrees so that the body 3 is smoothly pushed out from the underground wall.

  Further, if the formation angle of the bottom plate side ground and the lower surface portion of the steel frame 3A (= the opening face plate 3a and the bottom plate 3c) exceeds 40 degrees, the concrete will be There is a possibility that the vicinity of the tangent to the bottom plate 3c cannot be sufficiently filled. Therefore, the formation angle of the bottom plate side ground and the lower surface portion of the steel frame 3A (= the opening face plate 3a and the bottom plate 3c) is adjusted, and the underground wall concrete is sufficiently filled, and the keyway is formed. The formation angle of the bottom plate side ground pile and the lower surface portion of the steel frame 3A (= opening face plate 3a and bottom plate 3c) is set to about 20 to 40 degrees so that the body 3 is smoothly pushed out from the underground wall.

  The formation angle of the opening face plate 3a and the top plate 3b of the key groove forming body 3 and the formation angle of the opening face plate 3a and the bottom plate 3c are the friction coefficients of the top plate 3b and the bottom plate 3c, and the specific gravity of the key groove forming body 3 (described later). Depending on the extruding capability (described later) of the extruding device 5, it is necessary to appropriately change the respective forming angles within the range shown above.

  The inside of the key groove forming body 3 is filled with a curing material 4 having a specific gravity smaller than that of water, and the specific gravity of the key groove forming body 3 is made smaller than that of water. In this embodiment, for example, polystyrene is used as a hardener, and a steel plate is used as a shell forming material. However, if the specific gravity of the keyway forming body 3 is smaller than that of water, another hardener or shell forming material is used. Also good. Moreover, it is good also as a hollow body which consists only of an outer shell formation material, without using the hardening material 4, and is good also as a solid body shape | molded by the material (for example, plastic etc.) which comprises an outer shell.

  The extrusion device 5 that comes into contact with the back plate 3d of the key groove forming body 3 fills the inside with a liquid or gas, so that the rubber expands and pushes the key groove forming body 3 to the bottom plate side.

  Although the extrusion device 5 is preferably installed at a position intersecting the back plate 3d on the extension of a straight line connecting the center of the shaft having the same depth as the center of gravity of the key groove forming body 3 and the center of gravity of the key groove forming body 3, In this embodiment, the extrusion device 5 is installed at a position slightly shallower than the center of gravity of the key groove forming body 3 in consideration of the shape of the key groove forming body 3 and the like.

  A plurality of extrusion devices 5 can be used for one keyway forming body 3. However, the installation position of the extrusion device 5 depends on the formation angle between the opening face plate 3a and the top plate 3b of the key groove forming body 3, the formation angle between the opening face plate 3a and the bottom plate 3c, the thickness, etc. for the reasons described above. It is necessary to change accordingly.

  Here, in order to prevent the key groove forming body 3 from popping out, it is weaker than the pushing force of the pushing device 5 at the boundary between the upper and lower ends of the opening face plate 3a and the underground wall, and does not block the function of the pushing device 5. It is also possible to attach a spring-loaded pop-out prevention plate (not shown) having a proof stress.

  Moreover, as shown in FIG.1 (c), it is also possible to build the keyway formation body 3 alone in a vertical groove, without using the steel frame 3A. In this case, by applying a lubricant to the outer peripheral surface of the key groove forming body 3, it can be easily extruded by the extrusion device 5.

  FIG. 2 is a schematic view of the underground continuous wall formed by the keyway forming means in the first embodiment of the present invention. As shown in FIG. 2, the piece 9 of the underground wall having the keyway formed by using the keyway forming means 1 has a circumferential width of about 2.8 to 3.6 m and a height of about 9 m, for example. The minimum length and thickness necessary for the stability of the retaining ring are about 1.5 m, and the keyway 10 has a circumferential width of about 1 m, a height of about 5 m, and a depth of about 0.75 m. The width, height, and thickness of the underground wall piece 9 are appropriately changed according to the diameter of the shaft and the strength required for the stability of the earth retaining wall. Further, the size of the key groove 10 portion is appropriately changed depending on the lifting pressure.

Next, a method for forming the key groove 10 and a method for constructing the bottom plate using the key groove 10 will be described.
FIG. 3 is a construction procedure diagram of the bottom plate using the key groove forming means in the first embodiment of the present invention. FIG. 4 is a flow chart of the bottom plate construction procedure using the keyway forming means in the first embodiment of the present invention. Hereinafter, illustration of the steel frame 3A is omitted.

  First, as shown in FIGS. 3 (a) and 4 (a), the key groove forming body 3 has an opening face plate 3a serving as an opening of the key groove in the vertical groove 11 of the underground wall filled with muddy water. It is detachably provided in the steel frame 3A so as to contact the side ground. In this state, one end of the injection tube 6 is projected to the ground. The depth of the underground wall will be the minimum necessary for stable earth retaining.

  Next, as shown in FIG. 3B and FIG. 4B, the underground wall is completed by placing concrete in the longitudinal groove 11 and replacing it with muddy water. After concrete solidification, the opening face plate 3a of the keyway forming body 3 is exposed by excavating the interior 13 surrounded by the underground wall 12 underwater.

  Then, as shown in FIGS. 3 (c) and 4 (c), for example, an attachment-type drum 14 having a cleaning brush attached to the outer periphery is attached to, for example, a widening hydro machine 15 and lowered from the ground, and the drum 14 is The side surface portion of the underground wall 12 between the opening face plate 3a and the adjacent opening face plate 3a is washed by rotating.

And as shown in FIG.3 (d) and FIG.4 (d), the liquid or gas pressurized from the ground part through the injection | pouring pipe | tube 6 is inject | poured into the extrusion apparatus 5, The back plate of the keyway formation body 3 The rubber that is in close contact with 3d expands and pushes the key groove forming body 3 into the interior 13 surrounded by the underground wall 12. When the key groove forming body 3 is assembled into the reinforcing bar 2, the key groove forming body 3 can be easily extruded by applying a lubricant to the outer peripheral surface of the key groove forming body 3. And the keyway 10 is formed in the bottom part side surface of the underground wall 12 by the keyway formation body 3 being extruded.
Since the extruded key groove forming body 3 has a specific gravity smaller than that of water, it floats on the inside 13 surrounded by the underground wall 12 and can be easily recovered.
The formation status of the keyway 10 and the cleaning status of the cleaning surface are confirmed with an underwater camera or the like.

  Then, as shown in FIGS. 3 (e) and 4 (e), the reinforced concrete 16 is placed in the bottom of the interior 13 surrounded by the underground wall 12, or the reinforced concrete 16 manufactured on the ground is suspended. Lower and place on the bottom. Then, the concrete is placed in water between the outer peripheral end portion of the reinforced concrete 16 and the keyway 10 so that the bottom plate 17 is convex and the underground wall 12 and the bottom plate 17 are firmly integrated. As a result of investigating the joint between the underground wall 12 and the bottom slab 17 by FEM analysis, it has been found that it is safe even in unreinforced concrete under certain conditions.

  Finally, after the concrete is hardened, as shown in FIGS. 3 (f) and 4 (f), the water in the interior 13 surrounded by the underground wall 12 is drained to finish the bottom plate 17. Then, after finishing the bottom plate 17, the side wall work is started.

  By making the bottom plate 17 convex so that the underground wall 12 and the bottom plate 17 are firmly integrated, against the lifting pressure acting on the bottom plate 17, the weight of the bottom plate 17, the weight of the underground wall 12, and the underground wall It can resist by the frictional force between 12 and the ground. However, when the lifting pressure is large and the resistance force is insufficient, a jointed wall construction method is used in which ribs are provided in the outward direction of the side surface of the underground wall 12.

  FIG. 5 is a view showing the key groove forming member removing means in the second embodiment of the present invention. In the case of using the same members as in the first embodiment, the same reference numerals are given and the description thereof is omitted. As shown in FIG. 5, for example, an attachment-type rectangular parallelepiped magnet 18 is attached to the widening hydro machine 15, and the magnet 18 is lowered from the ground portion in the same manner as when cleaning the side surface of the underground connecting wall 8. 3 is close to the opening face plate 3a. Therefore, the key groove forming body 3 is attracted to the magnet 18 by the magnetic force, and the key groove forming body 3 is removed from the underground wall 12 to form the key groove 10. The key groove forming body 3 is recovered by being lifted in a state of being bonded to the magnet 18 of the widening hydro machine 15 or released by lifting the magnetic force in water and using the buoyancy of the key groove forming body 3 to recover. To do.

  FIG. 6 is a view showing the key groove forming member removing means in the third embodiment of the present invention. As shown in FIG. 6, the push-out device 20 with the jack installed at the bottom of the underground wall 12 surrounds the slide box 21 that contacts the back plate 3 d of the keyway forming body 3 and the underground wall 12. Jack 22 that is pushed out to the inside 13 side, a reaction force box 23 in which the jack 22 takes a reaction force when the slide box 21 is pushed out, one end connected to the jack 22 and the other end connected to the ground hydraulic generator. The hydraulic hose 24 is provided.

  After the cleaning of the underground wall 12 as in the first embodiment, the ground hydraulic pressure generator (not shown) is operated, the jack 22 is extended, and the keyway forming body 3 is surrounded by the underground wall 12. The keyway 10 is formed by extruding the inside 13.

  The keyway 10 formed in the second and third embodiments makes the bottom plate 17 convex so that the underground wall 12 and the bottom plate are firmly integrated as in the first embodiment.

It is the (a) installation condition perspective view inside the underground wall of the keyway formation means in the first example of the present invention, and (b) sectional view. It is the schematic of the underground continuous wall formed by the keyway formation means in the 1st example of the present invention. It is a construction procedure figure of the bottom plate using the keyway formation means in the first example of the present invention. It is a flowchart of the construction procedure of the bottom plate using the keyway formation means in the first embodiment of the present invention. It is a figure which shows the removal means of the keyway formation body in the 2nd Example of this invention. It is a figure which shows the removal means of the keyway formation body in the 3rd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Keyway formation means 2 Reinforcing bar 3 Keyway formation body 3A Steel frame 3B Insertion hole 3a Open face plate 3b Top plate 3c Bottom plate 3d Back plate 3e Side plate 4 Hardening material 5 Extruding device 6 Injection pipe 8 Underground connection wall 10 Key Groove 11 Vertical groove 12 Underground wall 14 Drum 15 Widening hydro machine 16 Reinforced concrete 17 Bottom slab 18 Magnet 20 Extruding device 21 with jack 21 Slide box 22 Jack 23 Reaction force box 24 Hydraulic hose

Claims (10)

Pre keyways formed in coupling position between the bottom plate at the bottom side of the diaphragm wall, a method of constructing the pit you uneven bonding the diaphragm wall and the bottom plate by the key groove,
A key groove forming body that is formed according to the key groove shape at the bottom plate coupling position and has an opening surface of the key groove facing the bottom plate side, and an extrusion device that pushes the key groove forming body to the bottom plate side. A shaft construction method characterized in that a key groove forming means is provided in a longitudinal groove to constitute the underground wall . In order to form the underground wall, the keyway forming means is provided in a longitudinal groove to place concrete, and after the concrete is hardened, the ground surrounded by the underground wall is excavated, and the excavation is completed. 2. The shaft construction method according to claim 1, wherein the pushing device is driven to push the key groove forming body toward the bottom plate to form a key groove. The construction method of a shaft according to claim 1 or 2 , wherein the key groove forming body has a specific gravity smaller than that of water. It is an extrusion apparatus used for the construction method of a shaft in any one of Claims 1-3 , Comprising: It consists of bag-shaped rubber | gum which expand | swells by inject | pouring a liquid or gas, The extrusion apparatus characterized by the above-mentioned. It is an extrusion apparatus used for the construction method of a shaft in any one of Claims 1-3 , Comprising: It consists of the jack extended and contracted by inject | pouring a liquid or gas, The extrusion apparatus characterized by the above-mentioned. At the bottom of the interior surrounded by the underground wall, construct reinforced concrete for underwater construction as the bottom plate, fill the gap between the reinforced concrete and the keyway with unreinforced concrete, and make the side cross section convex and the bottom plate and the underground wall The shaft construction method according to any one of claims 1 to 5 , wherein: The key groove forming body is in contact with the bottom plate-side ground, and an opening face plate that becomes an opening of the key groove;
A top plate obliquely installed with a predetermined inclination angle with respect to the opening surface plate at an upper portion of the opening surface plate;
A bottom plate obliquely provided at a lower portion of the opening face plate with a predetermined inclination angle with respect to the opening face plate;
A back plate that is parallel to the open face plate and formed on the top plate and the bottom plate;
The shaft construction method according to any one of claims 1 to 6 , wherein the shaft is formed in a keyway shape and includes side plates covered on both sides of the opening face plate. The construction of the shaft according to any one of claims 1 to 7 , wherein the steps from the completion of excavation of the ground surrounded by the underground wall to the construction of the shaft are performed in the order of bottom plate construction and dry-up. Method. A shaft constructed by the construction method according to any one of claims 1 to 8 , wherein the shaft is constructed with a continuous wall of an underground wall, and has a convex shape in a key groove formed on a bottom side surface of the underground wall. The structure of the shaft, characterized in that the bottom slabs of the slabs are concavo-convex joined. It is a structure constructed by the construction method according to any one of claims 1 to 8 , wherein an underground wall having a keyway on a side surface of the bottom and a convex bottom plate are formed by uneven coupling. Shaft structure.

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