JP2023077832A - Construction method of underground structure - Google Patents

Abstract

To provide a construction method of a structure allowing a new underground structure to be additionally constructed with efficiency as removing an existing underground structure even in a narrow land.SOLUTION: A construction method of an underground structure comprises steps of: constructing earth-retaining walls 3 on a circumference of an existing underground structure 2; removing existing underground floors with the first predetermined number of floors below a first floor of the existing underground structure 2; installing first temporary earth-retaining timbering supporting the earth-retaining walls 3 from a first foundation surface appearing after removing the existing underground floors to a level of the first floor; constructing a plurality of underground piles columns 6 downward from the first foundation surface to a first determined depth; constructing a new underground floor surface on the first foundation surface; sequentially constructing new underground structures with the first predetermined number of the floors to a new first floor surface 7 upward from the new underground floor surface; excavating the foundation downward from the new underground floor surface 7 to a second foundation surface 12; constructing the foundation on the second foundation surface 12; installing second temporary earth-retaining timbering 13; and sequentially constructing additional new underground structures with the second predetermined number of the floors.SELECTED DRAWING: Figure 7

Description

The present invention relates to an underground structure construction method for removing an existing structure and adding an underground structure.

For example, Patent Literature 1 describes a method of constructing an underground structure in which an existing underground structure is removed and a new underground structure is constructed. According to this underground structure construction method, a new underground structure is constructed while dismantling the existing underground structure based on the reverse construction method in which the underground structure is constructed while excavating the ground. This underground structure construction method includes the following steps.

A retaining wall will be constructed around the perimeter of the existing underground structure. Next, install structural pillars that will serve as temporary pillars through the underground skeleton of the existing underground structure. Next, the upper underground floor of the existing frame will be dismantled and the existing foundation will be excavated. Next, temporary supporting materials are attached to the structure pillars and retaining walls, and the entire existing frame is supported by the temporary supporting materials to construct the first floor preceding floor. Next, excavation will be carried out below the existing frame, and after the flooring is complete, the new foundation will be constructed. Thereafter, dismantle the existing underground skeleton, construct a new underground skeleton, and construct a new above-ground skeleton as appropriate in parallel.

JP-A-2001-262595

In the reverse construction method such as the method for constructing an underground structure described in Patent Literature 1, for example, difficulties may arise in deep-deep construction in the presence of nearby public transportation. For example, when a sloped road is provided on the outer periphery of a construction target area in the reverse casting method, it is difficult to place concrete using the press-in method, in which concrete is pressed in from the bottom of a vertical member such as a pillar using a pump. may become. In the reverse construction method such as the underground structure construction method described in Patent Document 1, for example, in order to ensure accuracy, after assembling the structural column on the ground (hereinafter also referred to as ground assembly), the structural column is assembled. Build underground. However, when the construction target is a narrow site, if the preceding floor is constructed on the first floor and then the structural column is constructed underground, the structural column will be longer than the site and the space for ground assembly will be lost. may not be ensured.

In the reverse construction method such as the method for constructing an underground structure described in Patent Document 1, when excavated soil and dismantled waste are accumulated in a temporary opening and carried out, they are not accumulated under the temporary opening. Otherwise, it may become difficult to move and operate heavy machinery.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of constructing a structure capable of constructing a new underground structure while efficiently removing the existing underground structure even in a narrow space.

One aspect of the present invention includes the steps of constructing an earth retaining wall around the perimeter of an existing underground structure, removing a first predetermined number of existing underground structures below the first floor of the existing underground structure, and A step of installing a first temporary earth retaining shoring that supports the earth retaining wall from the first ground surface revealed by removing the above to the height of the first floor; A step of constructing a structural column of, a step of constructing a new underground floor surface on the first ground surface, and sequentially constructing a new underground structure with a first predetermined number of floors upward from the new underground floor surface to create a new first floor A step of constructing up to the floor surface, sequentially constructing a new ground floor above the new first floor floor surface, and lowering the ground below the new underground floor surface to a second depth shallower than the first predetermined depth a step of excavating to a second ground surface of a predetermined depth; a step of constructing a foundation on the second ground surface; and a second temporary earth retaining support that supports the earth retaining wall from the foundation to the height of the new underground floor surface. and sequentially constructing additional new underground structures for a second predetermined number of floors upward from the foundation.

According to the present invention, when constructing a framing pillar, the capital of the framing pillar can be extended to the first ground surface, so that the framing pillar can be shortened. By shortening the framing column, there is an advantage that the framing column can be assembled even if the construction target area 1 is a narrow land. According to the present invention, the existing underground structure is removed, the new underground floor is constructed on the first ground surface, and the new underground structure is constructed above it based on the sequential construction method, so that the new underground structure is stabilized. can be constructed systematically.

Further, the first ground surface of the present invention may have a height in the depth direction that is shallower than the groundwater level.

According to the present invention, since a new underground structure is constructed at a position shallower than the groundwater level, the new underground structure can be constructed stably.

Moreover, the present invention may comprise the step of constructing an underground slope connecting the new underground structure of the first predetermined number of floors and the new first floor floor surface.

ADVANTAGE OF THE INVENTION According to this invention, an underground slope can be constructed based on the stable quality based on a sequential construction method.

The invention may also comprise the step of constructing additional underground ramps upwardly from said foundation.

ADVANTAGE OF THE INVENTION According to this invention, an additional underground slope can be constructed on the basis of stable quality based on a sequential construction method.

Further, in the present invention, when the underground slope and the additional underground slope are provided in the construction of the new underground structure and the construction of the additional new underground structure, the object to be removed using the underground slope and the additional underground slope It may be provided with a step of carrying out and carrying in a carried-in object.

According to the present invention, by constructing an underground slope and an additional underground slope, it is possible to easily transport objects to be removed and items to be brought in by vehicle.

According to the present invention, it is possible to efficiently remove an existing underground structure and extend a new underground structure even in a narrow space.

1 is a plan view showing a construction target range of an underground structure according to an embodiment of the present invention; FIG. It is a figure which shows the process of constructing a diaphragm wall of the constructing method of an underground structure. It is a figure which shows the process of removing a part of existing underground structure of the construction method of an underground structure, and constructing a structural column. It is a figure which shows the process of installing the 1st temporary earth retaining shoring of the construction method of an underground structure. It is a figure which shows the process of constructing a new underground structure of the construction method of an underground structure. It is a figure which shows after constructing a new underground structure of the constructing method of an underground structure. It is a figure which shows the process of constructing|constructing an underground slope of the constructing method of an underground structure. It is a figure which shows the process of excavating the ground under the new underground structure of the construction method of an underground structure. FIG. 10 is a diagram showing a state after construction of an additional new underground structure below the new underground structure in the construction method of the underground structure; FIG. 4 is a diagram showing a step of constructing an additional new underground slope in the method of constructing an underground structure;

Hereinafter, each process according to an embodiment of the method for constructing an underground structure according to the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, a construction target area 1 where a new building is to be constructed is, for example, a narrow lot. In the construction target range 1, for example, a highway, public transportation, other buildings, etc. are densely located nearby. In the construction target range 1, for example, the ground floor of the existing building has been removed, and the existing underground structure 2 of the first predetermined number of floors is left below the floor surface of the first floor. In this embodiment, the first predetermined number of floors is the number of floors of the existing underground structure 2, for example, two underground floors. A groundwater level W exists at a position lower than the floor of the existing underground structure 2 . In the construction target range 1, deep construction is carried out, and a new underground structure (described later) is added in the deeper ground than the existing underground structure 2.

First, an earth retaining wall 3 is constructed around the outer circumference of the existing underground structure 2 to prevent the ground from collapsing. The retaining wall 3 is constructed based on, for example, a diaphragm wall construction method. In the diaphragm wall construction method, for example, a wall-shaped ditch is excavated and a stabilizing liquid is injected into the ditch to prevent the excavated wall surface from collapsing. Alternatively, it is a method of constructing a continuous underground continuous wall (retaining wall 3) made of reinforced concrete or the like in the ground. The diaphragm wall is constructed based on SMW (Soil. Mixing Wall: soil cement construction method). A diaphragm wall is formed by mixing and agitating cement milk and soil in a groove to form a water stop wall, and inserting H-shaped steel to form a continuous earth retaining wall 3 .

The slot is formed, for example, by continuously drilling a columnar bore. A stabilizing liquid is injected into the borehole to hold the wall surface of the borehole in order to prevent the borehole wall from collapsing and to prevent the slime, which is excavation debris, from settling down. The stabilizing liquid is, for example, a bentonite solution, and quality is controlled based on specific gravity, viscosity, sand content, pH, and the like. The mountain retaining wall 3 may be constructed by other construction methods such as using sheet piles. The existing underground structure 2 is removed sequentially from the floor surface of the first floor. At this time, the internal space 2S of the existing underground structure 2 is filled with backfill soil 2B. The backfill soil 2B is, for example, fluidized soil. The backfill soil 2B is filled from the ground surface. The backfill soil 2B is excavated according to the state of removal of the existing underground structure 2 .

As shown in FIG. 3, a gantry F that serves as a temporary floor is constructed in the opening that appears after the first floor of the existing underground structure 2 is removed. The gantry F is constructed to cover a portion of the ground floor rather than the entire surface. The gantry F is constructed in a rectangular shape in plan view. In parallel with the installation of the gantry F, a plurality of gantry piles F2 temporarily installed to support the gantry F are installed below the gantry F. The gantry pile F2 is made of H steel, for example. The gantry pile F2 is embedded, for example, to a lower position than the second ground surface 12 (see FIG. 7) that supports the new underground structure 8, which will be described later. The gantry pile F2 is constructed by appropriately adding H steel. As a result, it becomes possible to carry out the object to be removed T below from the gantry F. A heavy machine such as a crane or a vehicle is placed on the gantry F. Concrete blocks and backfill soil 2B left behind by crushing the existing underground structure 2 below the gantry F are sequentially removed from above. The existing underground structure 2 is removed sequentially from above, and the first ground surface 5 is exposed.

A plurality of structural columns 6 are constructed from the first ground surface 5 to a first predetermined depth below. The structure column 6 is a support column for supporting the preceding floor that is constructed first in the reverse construction method. The structural column 6 is a column body formed by covering a steel material such as H-steel with concrete, for example. The structure column 6 is constructed integrally with the foundation pile 6A and used as a part of the structure. In the construction of the structural column 6, for example, while excavating a pile hole downward from the existing underground structure 2 or the first ground surface 5, a stabilizing liquid is injected into the pile hole, and the pile hole is opened while maintaining the stability of the pile hole. is dug downward to excavate a vertical hole-like space. The vertical hole-shaped space is formed, for example, as a diameter-expanded space with a tapered lower portion. The diameter expansion space is formed using, for example, a diameter expansion device (not shown) or the like.

A reinforcing bar cage (not shown) formed of reinforcing bars is erected in the expanding space. A foundation pile 6A into which concrete is placed is formed in the vertical hole. A structural column 6 is positioned and erected above the foundation pile before the concrete hardens. Into the vertical hole-shaped space, a structural column 6 assembled with H steel is inserted, the structural column 6 is embedded in the concrete, and after the concrete hardens, the structural column 6 and the foundation pile are integrally formed. be.

According to the above process, by constructing the structure column 6 from the first ground surface 5, the structure column 6 is constructed shorter than in the case of the reverse construction method in which the floor surface of the first floor is used as the preceding floor. be able to. By constructing the framing column 6 from the first ground surface 5, ground framing of the framing column 6 can be made possible.

When the expanded space is filled with concrete and the structure column 6 is constructed, the structure column 6 can support the load of the aboveground structure and resist the upward pulling force based on the moment applied to the aboveground structure. foundation piles. For example, a column-shaped reinforcing bar is inserted into the vertical hole-shaped space of the structural column 6 . After that, concrete is placed in the vertical hole-shaped space of the structural column 6, and the structural column 6 is constructed.

As shown in FIG. 4 , a first temporary earth retaining shoring 4 is installed between the opposing earth retaining walls 3 . The first temporary earth retaining shoring 4 is constructed, for example, in a frame that combines members such as H steel. Between the end portion of the first temporary earth retaining shoring 4 and the earth retaining wall 3 , an H-beam is arranged along the horizontal direction of the surface of the earth retaining wall 3 . The first temporary earth retaining shoring 4 supports, for example, the facing earth retaining wall 3 in the axial direction, and prevents the earth retaining wall 3 from bulging inward due to earth pressure. Using the space between the first temporary earth retaining shorings 4, removed objects T such as scraps and unloaded soil obtained by demolishing the existing underground structure 2 are carried out from the ground surface using a crane device K or the like. The first ground surface 5 has, for example, a height in the depth direction that is shallower than the groundwater level.

As shown in FIG. 5, a new subsurface 7 is then constructed above the first subsurface 5 . A new subsurface 7 is constructed, for example, on the first subsurface 5 and supported on top of the framing columns 6 . The new underground floor surface 7 is constructed of, for example, reinforced concrete, and can be used as a preceding floor in a reverse construction method for constructing an additional new underground structure 15 below the first ground surface 5 . During the construction of the new subterranean floor 7, the gantry pile F3 above from the first subsurface 5 is removed. The removed gantry pile F3 can be used as a second temporary earth retaining shoring 13, which will be described later. Above the new underground floor surface 7, a new underground structure 8 having a first predetermined number of floors is sequentially constructed based on the sequential construction method. A new underground structure 8 is constructed up to a new first floor floor 9 . At this time, the first temporary earth retaining shoring 4 is removed sequentially. The removed first temporary earth retaining shoring 4 can be used as a second temporary earth retaining shoring 13 which will be described later.

The new underground structure 8 is formed using, for example, a concrete press-in method, and is appropriately provided with a plurality of temporary openings H penetrating vertically. For the temporary opening H, for example, a crane device is used to carry out the removed objects, or carry in materials for constructing an additional new underground structure 15 below the new underground floor surface 7, and pour concrete. Used to insert and remove hoses for The new first floor floor 9 is constructed based on, for example, reinforced concrete construction. A plurality of temporary openings H penetrating vertically are appropriately provided on the new first floor floor 9 . The temporary opening H is provided, for example, at a position along the vertical direction of the temporary opening H provided in the new underground floor surface.

For example, the temporary opening H is used to carry out scraps from the dismantling of the existing underground floor using a crane device K or the like, unloaded soil, removed items such as part of the gantry pile, or materials for constructing a new underground structure 8. It is used for loading and unloading hoses for placing concrete.

In this embodiment, the new underground structure 8 is, for example, two floors underground. Since the new underground structure 8 is constructed above the groundwater level, as described above, it is possible to construct a framework that ensures quality in a state where groundwater does not flow. In addition, by preventing groundwater from flowing out, it is possible to prevent an increase in the load received by the SMW constructing the diaphragm wall in the direction of the inside of the building, thereby stabilizing the SMW.

A new underground structure 8 is then constructed, as shown in FIG. 6A. Since the new underground structure 8 is constructed by the forward casting method, it is possible to stably ensure the quality of the concrete. Temporary opening H may be closed if necessary.

As shown in FIG. 6B, part of the new underground structure 8 may be provided with an underground slope 10 that connects the new underground floor surface 7 and the new first floor floor surface 9 . The underground slope 10 is, for example, made of reinforced concrete and constructed by the forward casting method, but it may be a temporary structure that is removed later, or it may be assembled so as to be dismantled using H steel or the like.

For example, the underground slope 10 may be constructed for each floor of the new underground structure 8 or may be constructed so as to connect the new underground floor surface 7 and the new first floor floor surface 9 . The underground slope 10 can be used as a passageway for vehicles to carry out removed objects such as scraps and excavated earth from the dismantled existing underground floor, and to carry in materials for constructing a new underground structure 8. - 特許庁

As shown in FIG. 7 , after the construction of the new first floor floor 9 , new ground floors 11 are sequentially constructed above the new first floor floor 9 . Simultaneously with construction of the new ground floor 11, the ground below the new underground floor surface 7 is excavated. At this time, the ground is excavated to a second ground surface 12 of a second predetermined depth shallower than the first predetermined depth at which the lower ends of the structural columns 6 are provided. An underground space is formed between the new underground floor surface 7 and the second ground surface 12 , and the new underground floor surface 7 is supported by a plurality of exposed structural columns 6 .

At this time, the temporary opening H is used, for example, by using a crane device or the like to carry out the excavated soil or the like generated by excavating the ground, and the materials for constructing the new underground structure 8 are carried in and used as the gantry pile F2. Some of the members that have been used are brought in to serve as members of the second temporary earth retaining shoring 13, and are used to take in and out hoses for placing concrete. Moreover, the gantry pile F2 is removed one by one according to the excavation depth of the ground.

A second temporary earth retaining shoring 13 is installed between the opposing earth retaining walls 3 . The second temporary earth retaining shoring 13 is constructed in a frame using the members of the first temporary earth retaining shoring 4 and the gantry pile F2, for example. Between the end portion of the second temporary earth retaining shoring 13 and the earth retaining wall 3 , an H-beam is arranged along the horizontal direction of the surface of the earth retaining wall 3 . Like the first temporary earth retaining shoring 4, the second temporary earth retaining shoring 13 supports the opposing earth retaining wall 3 in the axial direction, and the earth retaining wall 3 bulges inward under the earth pressure. to prevent

When the underground slope 10 is provided, excavated soil or the like generated by excavating the ground may be carried out by a vehicle or heavy machinery using the underground slope 10 after being carried out to the new underground structure 8 through the temporary opening H. .

As shown in FIG. 8, the second ground surface 12 is excavated to substantially the same height as the upper ends of the foundation piles 6A. A newly added underground floor 14 is constructed on top of the second ground surface 12 . Above the newly added underground floor surface 14, additional new underground structures 15 for the second predetermined number of floors are successively constructed based on the sequential construction method. In this embodiment, the second predetermined number of floors is two floors. That is, in this embodiment, the additional new underground structure 15 is the 3rd basement floor and the 4th basement floor. The additional new underground structure 15 is constructed of reinforced concrete by a method such as a concrete press-in method. The structure pillar 6 becomes a part of structure of the additional new underground structure 15 and is integrated. The foundation piles 6A support the additional new underground structure 15 and the new underground structure 8.

Also, as shown in FIG. 9, an additional underground slope 16 may be constructed on a portion of the additional new underground structure 15 . The additional underground slope 16 may be constructed, for example, for each additional new underground structure 15 , or may be constructed from the newly added underground floor surface 14 to the new underground floor surface 7 . The additional underground slope 16 is constructed of reinforced concrete, for example, but it may be a temporary structure that will be removed later, or it may be assembled using H-steel or the like so that it can be dismantled.

Through the additional underground slope 16, items to be carried out, such as waste, are carried out, and items to be carried in, such as materials, are carried in. Based on the above steps, the additional new underground structure 15 is constructed between the newly added underground floor surface 14 and the new underground floor surface 7 . Each temporary opening H is closed after the load is carried out using a crane device or the like. Each temporary opening H is left in place and utilized as part of the additional new underground structure 15 when closure is not required.

According to the construction method of the underground structure described above, when constructing the structural column 6 by the reverse construction method, the capital of the structural column 6 can be set up to the first ground surface 5. length can be shortened. By shortening the framing column, there is an advantage that the framing column can be assembled even if the construction target area 1 is a narrow land.

According to the underground structure construction method described above, since the new underground structure is constructed based on the sequential construction method from the first ground surface 5 above the groundwater level, the new underground structure can be constructed stably. can be done. In addition, by providing a temporary opening H in the new first floor floor and additional new underground structure, it is possible to easily transport carry-out and carry-in items by heavy machinery. In addition, when constructing an additional underground slope in a part of a new underground structure or in a part of an additional new underground floor, it is possible to easily transport items to be carried out and items to be brought in using vehicles and heavy machinery.

An embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the scope of the invention. For example, underground ramp 10 and additional underground ramp 16 may be, for example, designed structures or temporary structures that are later removed.

1 Construction target area 2 Existing underground structure 3 Earth retaining wall 4 First temporary earth retaining shoring 5 First ground surface 6 Structural column 7 New underground floor surface 8 New underground structure 9 New 1st floor floor surface 10 Underground slope 11 New Ground floor 12 Second ground surface 13 Second temporary earth retaining shoring 14 Newly added underground floor surface 15 Additional new underground structure 16 Additional underground slope F Gantry

Claims (5)

A process of constructing a retaining wall around the perimeter of the existing underground structure;
removing a first predetermined number of existing underground floors below the first floor of the existing underground structure;
A step of installing a first temporary earth retaining shoring for supporting the earth retaining wall from the first ground level revealed by removing the existing basement floor to the height of the first floor;
constructing a plurality of structural columns to a first predetermined depth below the first ground surface;
constructing a new subsurface on said first toposurface;
a step of sequentially constructing a new underground structure having a first predetermined number of floors upward from the new underground floor surface to a new first floor floor surface;
While sequentially constructing a new above-ground structure above the new first floor floor, the ground below the new underground floor is a second ground having a second predetermined depth shallower than the first predetermined depth. a step of drilling to the surface;
building a foundation on the second toposurface;
installing a second temporary earth retaining shoring that supports the earth retaining wall from the foundation to the height of the new underground floor;
a step of sequentially constructing an additional new underground structure for a second predetermined number of floors above the foundation;
A method for constructing an underground structure, comprising: The first ground surface has a height in the depth direction that is shallower than the groundwater level,
The method for constructing an underground structure according to claim 1. A step of constructing an underground slope that connects the new underground structure of the first predetermined floor and the new first floor floor surface,
The method for constructing an underground structure according to claim 1 or 2. constructing an additional underground slope upwards from the foundation;
A method for constructing an underground structure according to claim 3. When the underground slope and the additional underground slope are provided in the construction of the new underground structure and the construction of the additional new underground structure, the underground slope and the additional underground slope are used to carry out and carry in the objects to be removed. Equipped with a process of importing things,
The method for constructing an underground structure according to claim 4.

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