JP4022687B2 - Construction method for underground structures - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a construction method of an underground structure that is constructed at a relatively shallow position, in the case of constructing an underground structure under a narrow-section road or a limited site, especially when a large-section tunnel is used when excavation cannot be performed. Suitable for construction of underground structures that are widely used as urban facilities such as underground transportation facilities such as underground passages and subways, lifeline facilities such as electric power, gas, and water and sewage, as well as subway station buildings, underground shopping centers, underground parking lots, etc. It is used.
[0002]
[Prior art]
Up to now, as a method of constructing underground structures such as underground transportation facilities under the ground level in limited facilities such as roads, railways, rivers, parks, etc. in urban areas, the site area is wide compared to the site When there is a sufficient margin, the open-cut method of construction from the ground is used.Other construction methods include a circular or rectangular large cross-section shield method, and the outer shell of a large cross-section tunnel with multiple small or medium cross-section shield machines. After construction, the MMST method, which excavates the interior to complete the large section underground space, is used.
[0003]
[Problems to be solved by the invention]
However, in the case of the excavation method, if the excavation scale is very large, temporary works such as retaining walls, supporting piles and support works that hold the surrounding natural ground will be large, and a large amount of excavated and backfilled soil will be required. The processing and the handling became a big subject.
[0004]
In particular, when constructing an underground structure that has a relatively large area within a very limited site and the excavation cross-sectional width changes midway using the open-cut method, the retaining wall for excavation is used as the surrounding structure. Since it is necessary to install them close to each other, the deformation and settlement of the surrounding ground caused by large-scale excavation has a large effect on the surrounding ground structure, and protective work such as ground improvement is necessary to reduce the influence. Met.
[0005]
In addition, since a vast work zone is required on the ground during construction, the use of ground facilities such as roads and parks on the ground must be partially restricted, and traffic congestion will be caused, resulting in a significant impact on citizens' lives. There was also a case.
[0006]
On the other hand, in the case of the large cross-section shield method, the shield machine becomes large and forced to be very uneconomical.In particular, in the case of the circular cross-section shield method, a so-called dead space is generated and the excavated soil The volume became enormous, the tunnel excavation cost increased, making it extremely uneconomical, and there were environmental issues such as residual soil disposal.
[0007]
In addition, to construct an underground structure with a wide cross-section and cross-sectional width that changes in the middle, a special specification shield machine is required, and the cross-section of shield holes that can be constructed is very limited. There was a problem.
[0008]
The present invention has been made in order to solve the above-mentioned problems, and it has little influence on neighboring existing structures, and a space as large as possible under an extremely limited road or site such as an urban area. An object of the present invention is to provide a construction method of an underground structure capable of constructing the underground structure possessed very efficiently and safely.
[0009]
[Means for Solving the Problems]
The construction method of an underground structure according to claim 1 is a construction method of an underground structure for constructing an underground structure having a plurality of floors, and includes a step of excavating a shield hole, and a retaining wall below the shield hole. A step of excavating the ground below the shield hole, a step of constructing a floor slab of each floor, and a step of constructing a side wall of each floor, wherein the shield hole is a space for one underground floor And excavating while holding a natural mountain by a steel shell or a steel segment and a middle pillar, the mountain retaining wall is constructed using the shield hole as a work space, and the floor slab of each floor The floor slab of the first basement is built in the floor portion of the shield hole, the side wall of the first basement is built in the shield hole, and the second floor below the floor slab and the side wall of the first basement. Subsequent floors It is characterized in that to construct Love and sidewalls.
[0010]
The shield hole in this case is a part used as the first basement of the underground structure after construction, and is also used as a work space when constructing the underground structure during construction. It is necessary to make a shield hole having a space of minutes.
[0011]
Further, the ground of the shield hole is covered with a steel shell or a steel segment as shown in FIG. 6, for example, but it may be covered with an existing segment such as an RC segment. It can be formed relatively easily and inexpensively from any steel plate to any size depending on the size and shape of the shield hole, and can be reinforced as a whole or partly by filling concrete as required, It has a high degree of freedom during production and construction, and is suitable as a lining material in this case.
[0012]
In addition, when the frontage (width) of the underground structure is very large, multiple shield holes are separated from each other by a predetermined distance, and then the ground between the shield holes is excavated to form one large space. However, it is also possible to construct an underground structure by constructing mountain retaining walls using this large space as a work space.
[0013]
The construction method of the underground structure according to claim 2 is the construction method of the underground structure according to claim 1, wherein the floor slab and the side wall of each floor after the second basement floor are bottomed while excavating the ground below the shield hole. It is characterized by building sequentially up to the floor.
[0014]
This construction method is a so-called reverse-winding concrete construction method. According to this construction method, the side wall and floor slab after construction are used as mountain stops and beams when constructing the side wall and floor slab of the next floor. Efficiency can be improved.
[0015]
The construction method of the underground structure according to claim 3 is the construction method of the underground structure according to claim 1, wherein the floor slabs and side walls of the second and subsequent floors are excavated from the ground below the shield hole to the lowest floor. After that, the construction is performed in order from the lowest floor to the upper floor.
[0016]
The construction method for an underground structure according to claim 4 is the construction method for an underground structure according to any one of claims 1 to 3 , wherein the steel shell or the steel segment of the shield hole is provided with the steel shell or the steel segment. An opening for constructing a mountain retaining wall is provided below the shield hole continuously in the digging direction, reinforcing beams are installed on both sides thereof, and a plurality of transverse beams are installed between the reinforcing beams. Is.
[0017]
The construction method of the underground structure according to claim 5 is the construction method of the underground structure according to any one of claims 1 to 4, wherein the mountain retaining wall is constructed from the shield hole by the column-type underground continuous wall construction method. It is characterized by this.
[0018]
One example of a columnar underground continuous wall method is the SMW method. For example, a drilling machine equipped with a drilling bit at the tip is used, and the excavated soil excavated with this drilling machine and the cement milk injected are mixed with stirring. This is a construction method of an underground continuous wall in which a column array is formed and a section steel such as H-section steel is inserted into the column array as a core pile. In addition, an underground continuous wall RC method or the like can also be used.
[0019]
The construction method for an underground structure according to claim 6 is characterized in that in the construction method for an underground structure according to any one of claims 1 to 5, an intermediate pile is constructed below the shield hole. This construction method ensures the necessary bearing capacity by constructing an intermediate pile as a support pile below the shield hole when the frontage (width) of the underground structure is very wide or the construction ground is not always stable. Is.
[0020]
In any of the construction methods according to claims 1 to 6, the cross-sectional shape of each shield hole is not particularly limited, but when the excavation cross-section of the shield hole is a rectangular cross-section, it is used as an underground space. It is desirable that a useless space is hardly generated and the amount of excavated soil is smaller than that of the excavated section.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an example of an underground structure constructed by an underground structure construction method according to the present invention. In the figure, a ceiling slab 1 on the first basement floor is arranged at a relatively shallow position, and floors of the respective floors are arranged below it. Slabs 2a and 2b and a basic slab 3 are arranged, and side walls 4a, 4b and 4c of each floor are arranged on both sides thereof.
[0022]
In addition, between the ceiling slab 1 and the floor slab 2a on the first basement floor, between the floor slabs 2a and 2b on each floor, and between the foundation slab 3 and the floor slab 2b on the floor immediately above, a column or partition wall on each floor 5a, 5b, and 5c may be arranged, respectively.
[0023]
The ceiling slab 1 on the first basement floor, the floor slabs 2a and 2b on each floor, the foundation slab 3 and the side walls 4a, 4b and 4c on each floor, and the pillars or partition walls 5a, 5b and 5c on each floor are all RC structures or SRC structures. It is built by etc.
[0024]
Next, an example of the construction method of the underground structure will be described based on the examples shown in FIGS.
[0025]
(1) First, a shield machine (not shown) is assembled in a vertical shaft (not shown) constructed in advance as a starting base for the shield machine. For the shield machine in this case, a shield machine having a plurality of face plates for excavating the face and a function of expanding and reducing the diameter to change the diameter of the shield hole and configured in a flat rectangular shape is used. .
[0026]
{Circle around (2)} Next, a shield hole 6 having a space corresponding to the first floor of the underground structure A to be constructed by propelling a shield machine from this shaft is dug into a rectangular cross section. At the same time, the steel shell 7 is assembled at the tail portion of the shield machine, and the ground of the shield hole 6 is covered with a steel shell segment 7A composed of a plurality of steel shells 7. Moreover, the middle pillar 8 is built in the steel shell segment 7A (refer to STEP.1).
In this case, the diameter of the shield hole 6 is changed by operating the diameter expansion and contraction functions of the shield machine as necessary.
[0027]
As shown in FIGS. 8A and 8B, for example, the steel shell 7 used here includes a plurality of main girder plates 7a and 7a installed substantially in parallel and end portions of the main girder plates 7a and 7a. A plurality of rib plates 7c installed at predetermined intervals between the joint plates 7b, 7b and the main girder plates 7a, 7a respectively installed between them, and a skin plate installed on the natural ground side of the frame made of these members 7d formed in a rectangular plate shape is used.
[0028]
Further, in particular, the steel shell 7 at the position where the intermediate pile to be described later is driven is formed with a pile erection hole 7e for driving the intermediate pile, as shown in FIG. 8C, for example, and a reinforcing rib 7f around the hole. Use a steel shell to which is attached.
[0029]
And the steel shell 7 formed in this way is installed in the ground of the shield hole 6 adjacent to each other in the circumferential direction and the excavation direction, and adjacent to the circumferential direction and the excavation direction of the shield hole 6. 7 are joined together by joint fittings such as joint bolts.
[0030]
The middle column 8 is a reinforcing material for the steel shell segment 7A, and is formed by using a shape steel such as an H-section steel in the shield hole 6 at predetermined intervals in the direction of excavation. In this case, a receiving base (not shown) and a receiving beam (not shown) are bridged in the digging direction or radial direction of the shield hole 6 on the floor and ceiling of the steel shell ring 7A, and the receiving base and the receiving needle beam are connected to each other. The middle pillar 8 shall be built in between.
[0031]
(3) Next, the space inside the shield hole 6 is set as a work space, and the intermediate pile 9 is driven into the ground below the shield hole 6 (see STEP 2). The intermediate pile 9 is driven into the ground through the pile piercing hole 7e.
In this case, a shape steel such as an H-section steel is used for the intermediate pile 9 and the shape steel is driven into the shield hole 6 while being appropriately added. Moreover, the middle pillar 9a is built in the upper end part of each intermediate | middle pile 9 for the same purpose as the middle pillar 8, and the upper end part is received by a receiving beam (illustration omitted) similarly to the upper end part of the middle pillar 8.
[0032]
(4) Next, a part of the steel shell segment 7A is removed at both end portions a of the floor portion of the steel shell segment 7A to form an opening 10 continuous in the digging direction of the shield hole 6 (see STEP.3). ). Further, for example, as shown in FIGS. 6C and 7, reinforcing beams 11 and 11 are continuously installed on both sides of the opening 10 in the direction in which the shield hole 6 is advanced, and between the reinforcing beams 11 and 11. Further, the strength of the steel shell segment 7A due to the formation of the opening 10 is prevented by bridging the cross beam 12 at predetermined intervals. In this case, H-shaped steel or the like is used for the reinforcing beam 11 and the lateral beam 12.
[0033]
(5) Next, the mountain retaining wall 13 is constructed below the opening 10 (see STEP. 4 to 6). In this case, the retaining wall 13 is formed with a columnar body 13a by, for example, using a drilling machine having a drilling bit at the tip and stirring and mixing the excavated soil excavated by the drilling machine and the injected cement milk. Then, it is constructed by a column-column type underground continuous wall construction method in which a section steel such as H-section steel or a steel pipe is inserted as the core pile 13b in the column column body 13a. The opening 10 is filled with concrete 13c after the mountain retaining wall 13 is constructed.
[0034]
(6) Next, the middle column 14 is built at the upper end of the mountain retaining wall 13 and the steel beam segment 7A is reinforced by spanning the beam 15 between the middle columns 14, 14, and the steel shell segment 7A The steel shell 7 and the middle pillar 8 in the floor are removed (see STEP 7). In this case, the middle pillar 14 and the cut beam 15 are made of a section steel such as H-section steel.
[0035]
(7) Next, the floor slab 2a on the first basement is constructed at the position where the steel shell 7 is removed, and the ceiling slab 1, the side walls 4a and 4a on the first basement, and the pillar or partition wall 5a on the first basement are respectively provided. Build (see STEP.8). In this case, the middle column 14 is used as a steel frame material of the side wall 4a, and the middle column 9a is used as a steel frame material of the column or the partition wall 5a.
[0036]
(8) Next, the ground below the floor slab 2a is dug down to the depth of the second basement floor, and the floor slab 2b of the second basement floor is constructed at the bottom, and the side walls 4b and 4b of the basement second floor are constructed respectively ( (See STEP 9).
Similarly, after digging the lower ground of the floor slab 2b to the depth of the third basement floor, the foundation slab 3 and the side walls 4c, 4c are constructed together with the floor slab of the third basement floor (STEP. 10, 11). reference).
[0037]
{Circle over (9)} Then, the beam 15 and unnecessary middle pillars are removed to complete the construction (see STEP 12).
In this case, the mountain retaining walls 13, 13 and the floor slabs 2a, 2b, 2c and the foundation slab 3 of each floor are constructed first, and then the side walls 4a, 4b, 4c of each floor and the pillars or partitions 5a, 5b of each floor, 5c may be constructed.
[0038]
In particular, when the frontage (width) of the underground structure A is particularly wide, for example, as shown in FIG. , 6 can be excavated to form one large space 6A, and the mountain retaining wall 13 can be constructed by using the large space 6A as a work space to construct the underground structure A.
[0039]
In this case, in order to excavate the ground portion B between the shield holes 6, 6, for example, a steel pipe or a section steel is bridged in parallel between the upper ends of the shield holes 6, 6, and then the shield hole 6 side The ground portion B below the mountain stopper is excavated to form a large space 6A, the ground is covered with a steel shell, and a plurality of middle pillars are built as a reinforcing material for the steel shell segment.
[0040]
【The invention's effect】
The invention of the present application is as described above, and an underground structure having a necessary underground space can be easily constructed by a non-open-cutting method. Is unnecessary, and the amount of temporary structures and excavated soil can be minimized, and the amount of backfilled soil is not generated, and the surrounding existing structures are hardly adversely affected.
[0041]
In addition, since the excavation cross section can be changed freely, it is possible to effectively use the limited land width and the space sandwiched between existing buried objects, even for underground structures that have a wide cross section or change in width, even though it is a non-open cutting method. It can be easily constructed using it.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an example of an underground structure.
FIGS. 2A to 2C are longitudinal sectional views showing a construction process. FIGS.
FIGS. 3A to 3C are longitudinal sectional views showing a construction process. FIGS.
FIGS. 4A to 4C are longitudinal sectional views showing a construction process. FIGS.
FIGS. 5A to 5C are longitudinal sectional views showing a construction process. FIGS.
6A and 6B show an example of a shield hole, where FIG. 6A is a partial perspective view of the shield hole, FIG. 6B is an enlarged view of portion A in FIG. 5C, and FIG. 6C is a cross-sectional view along line BB in FIG. It is.
7 is an enlarged cross-sectional view of a portion C in FIG.
FIG. 8 shows an example of a steel shell, (a) and (b) are plan views of the steel shell, and (c) is a cross-sectional view of the steel shell.
FIGS. 9A to 9D are plan views showing a construction process. FIGS.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Basement ceiling slab 2a Floor slab 2b of each floor Floor slab 3 of each floor 3 Side slab 4a Side wall 4b of each floor Side wall 4c of each floor Side wall 5a Column or partition wall 5b of each floor Column or partition wall 5c of each floor Column of each floor Or partition wall 6 Shield hole 7 Steel shell 7A Steel shell segment 8 Middle column 9 Middle pile 10 Opening 11 Reinforcement beam 12 Cross beam 13 Stop wall 14 Middle column 15 Cut beam

Claims (6)

A construction method of an underground structure for constructing an underground structure having a plurality of floors, the step of digging a shield hole, the step of constructing a retaining wall below the shield hole, and the ground below the shield hole And a step of constructing a floor slab of each floor, and a step of constructing a side wall of each floor, and the shield hole is excavated into a rectangular cross section having a space for one underground floor, and a steel shell or Digging while holding a natural mountain by a steel segment and a middle pillar, the mountain retaining wall is constructed using the shield hole as a work space, and the floor slab and floor slab of each floor are the shield Build in the floor part of the hole, build the side wall of the first basement floor in the shield hole, and construct the floor slab and side wall of each floor after the second basement floor below the floor slab of the first basement floor and the side wall. Characterize Construction method of the lower structure. The construction method of an underground structure according to claim 1, wherein the floor slab and the side wall of each floor after the second basement floor are constructed in order up to the lowest floor while excavating the ground below the shield hole. 2. The underground structure according to claim 1, wherein the floor slab and the side wall of each floor after the second basement floor are constructed in order from the bottom floor to the upper floor after excavating the ground below the shield hole to the bottom floor. Construction method of things. In the steel shell or steel segment of the shield hole, openings for constructing a retaining wall below the steel shell or steel segment are continuously provided in the direction of the shield hole, and reinforcing beams are provided on both sides thereof. The construction method of an underground structure according to any one of claims 1 to 3, wherein a plurality of horizontal beams are installed between the reinforcing beams.   The construction method for an underground structure according to any one of claims 1 to 4, wherein the mountain retaining wall is constructed from a shield hole by a columnar underground continuous wall construction method.   The construction method for an underground structure according to any one of claims 1 to 5, wherein an intermediate pile is constructed below the shield hole.

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