JPH0748845A - Execution method for underground structure by artificial ground - Google Patents

Abstract

PURPOSE:To construct an underground structure in a short period without giving a constraint to the ground function of an existing facility. CONSTITUTION:An artificial ground 10 constructed in advance on the excavation object ground face G is supported with jacks 20. The ground directly below the artificial ground 10 is excavated to the prescribed depth, the artificial ground 10 is lowered to the position of the support point of a continuous wall 35 provided at part of the excavated ground via the jacks 20, and the lining face 12 of the artificial ground 10 is set to the ground height nearly equal to the excavation object ground face G. The ground directly below the artificial ground 10 is excavated in succession, the ground face is lowered to the foundation ground of an underground structure, and an underground space is constructed. The underground structure is constructed in the underground space, and the artificial ground 10 is left at this place as a permanent structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing an underground structure using artificial ground, and in particular, an artificial structure capable of constructing a medium-sized or large-scale underground structure in a short period of time without almost stopping the above-ground function. The method of constructing an underground structure using the ground.

[0002]

2. Description of the Related Art In recent years, many large-scale underground structures utilizing underground spaces such as subway stations and underground malls have been constructed in urban areas. When constructing these underground structures, it is important to proceed with the construction without deteriorating the functions of roads and public spaces on the ground. Therefore, in excavation work such as excavation under the road, road surface lining is carried out so that ground traffic etc. will not be hindered. This road surface lining is usually constructed such that a girder is erected in a predetermined range and then a girder is erected on an intermediate pile constructed with a predetermined span, and a lining plate is laid on it.
Then, an automobile or the like passes on the lining plate. Normally, in such excavation work, some lanes of the road are closed at midnight in order to minimize traffic obstacles, part of the road lining is removed during that time to carry out excavated soil and materials, etc. Is designed to Therefore, the road surface lining is designed as a temporary structure, and each structure has a structure that ensures the minimum passage of vehicles.

By the way, in order to solve the land shortage in urban areas, a space is formed in an underground part of an existing facility such as a park or a playground, and the space is effectively used to form an underground parking lot or various large scales. There is a request to proceed with the construction of underground facilities. When constructing such an underground structure, a large-scale excavation work is performed from the ground, subsequently the main body structure is built in the underground part, and finally the main body structure is backfilled,
The above-ground part is restored to its original shape, and a series of construction is completed. In this case, the construction area of the underground structure to be constructed may be large, so the site within the prescribed range on the ground shall be closed and closed with a curing panel etc., and the construction machine should be carried into the site and shut off from the outside. Each construction is often done.

[0004]

[Problems to be Solved by the Invention] However, in the site of an existing facility as described above, when the construction is closed by closing the use of the site to construct an underground structure, the following problems occur. Occurs. (1) When constructing a structure in the basement of a plaza such as a park, the plaza cannot be completely closed for a long period of time.
In addition, construction may not be permitted unless environmental protection such as green areas on the ground is ensured. (2) Since the surrounding environment of conventional facilities and the construction area are completely divided, it is not possible to actively inform the neighboring users of existing facilities of the progress of construction. For this reason, for the users in these neighborhoods, the only impression is that the construction is annoying, and there is a problem in that the construction proceeds without understanding of the construction, and the residents of the neighborhood feel annoyance. There is a fear. (3) When the conventional excavation work is performed from the ground, it is easily affected by the weather, and depending on the season such as the rainy season and the typhoon, the process delay due to bad weather may become serious. (4) If a temporary structure such as road lining is provided to secure ground transportation, the ground function must be stopped again after the underground structure is completed to remove the temporary structure and restore the existing structure. I won't.

Therefore, an object of the present invention is to solve the problems of the above-mentioned conventional technique, to ensure the above-ground function of the existing facilities, etc., and to smoothly carry out each construction in the underground. To provide a method for constructing an underground structure using artificial ground.

[0006]

In order to achieve the above object, the present invention supports an artificial ground pre-constructed on a ground surface to be excavated by an elevating device so that the ground immediately below the artificial ground is brought to a predetermined depth. After excavating, the artificial ground is lowered to the support point position provided on a part of the excavated ground through the elevating device, and the lining surface of the artificial ground and the ground surface to be excavated are substantially equal to each other. Then, continuously excavating directly below the artificial ground to form an underground space by lowering the ground to the foundation ground of the underground structure, and then constructing the underground structure in the underground space, the artificial ground It is characterized in that it is left at the position.

[0007]

According to the present invention, the artificial ground previously constructed on the ground surface to be excavated is supported by the lifting device, the ground immediately below the artificial ground is excavated to a predetermined depth, and a part of the excavated ground is The artificial ground is lowered to the support point position provided in the via the elevating device, the lining surface of the artificial ground and the ground surface to be excavated are substantially equal ground height, and then the area immediately below the artificial ground is excavated. The basement of the underground structure is lowered to form an underground space, and then the underground structure is constructed in the underground space, and the artificial ground is left at the position. Since each construction step such as excavation can proceed in the space below the artificial ground of the same ground height as the excavation target ground surface without being affected, it is possible to proceed with each construction without restricting the ground function. Book artificial ground Can be reduced to minimize the work involved in the removal and Genkatachi restoration work of temporary structures by leaving as a structure, it is possible to shorten the construction period.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for constructing an underground structure with artificial ground according to the present invention will be described below with reference to the accompanying drawings.
In the following examples, description will be given with reference to the drawings on the assumption that an underground parking lot is constructed in an underground part of a ground or a park by the construction method according to the present invention. Note that FIG. 5 and FIG.
Although an example of the underground parking lot at the time of completion is shown in the above, it goes without saying that various structures can be constructed as the underground structure and the target structure is not limited at all. FIG. 5 is a schematic plan view schematically showing a planar layout within the site of the facility 50. Several buildings 51 and other buildings 52 such as incidental buildings have already been constructed on the site.
There is a ground G surrounded by 1, 52. Under the ground G, a plane shown by a broken line has a circular shape, and an attempt is made to construct an underground parking lot P on, for example, an underground multi-storey floor as shown in FIG. By the way, since the ground G on the ground is constantly exercised, it is impossible to construct such an underground parking lot P by closing the ground for a long period of time for construction. Therefore, it is particularly effective to construct an underground parking lot or the like as an underground structure using the artificial ground according to the present invention.

FIG. 1 is a schematic perspective view schematically showing a part of the artificial ground constructed in the construction method according to the present invention. The figure (a) has shown the state in which the artificial ground 10 is installed in the ground part. In this state, the artificial ground 10 is supported by the pile head 30a of the support pile 30 via the hydraulic jack 20, and in this state, the primary excavation is performed directly below the artificial ground 10. In the same figure (b), the artificial ground 10 is jacked down to a predetermined position in the ground, the lining surface 12 at the top of the artificial ground 10 and the ground surface around the ground G are at the same level, and the entire ground is flat. It shows the state.

First, referring to FIG. 1A, the artificial ground 10
The configuration of will be described. As shown in the drawing, the artificial ground 10 has a circular cross section in a plan view, and is composed of an artificial ground truss 11 made of a steel truss structure having a predetermined beam height, and a lining surface 12 corresponding to the ground surface. This figure is shown with a part of the lining surface 12 cut away. Of these, the artificial ground truss 11 is mainly composed of a cross girder 13 (large girder) having a beam span substantially equal to the diameter of the artificial ground 10 and a plane shape of a substantially cross shape. It has a box truss structure, and a circular reinforcing ring truss 14 is formed at the central intersection position. Further, a plurality of truss beams 15, 15 ... Reinforcing the cross girder 13 and supporting the lining surface 12 are installed in parallel between the cross girder 13 and the outer peripheral ring truss 16. The diagonal members of the truss members 13, 14, 15, 16 are not shown for simplification of the drawing.

Here, the safety passage will be briefly described. The artificial ground 10 used in the present invention is provided with a safety passage 17 so that the site where the excavation work or the skeleton construction that is proceeding underground is performed can be seen from above. Safety passage 1
7 is provided inside the cross girder 13 having the box-shaped cross section described above. A passage with a width of about 2.0 m and a height of about 2.5 m is secured in the cross girder 13 and necessary handrails, floor boards and skirting boards are provided. It is also preferable that the entire construction under the eye can be seen well and that the side surface of the passage is covered with a transparent reinforced plastic plate or the like in order to prevent a fall or an object from falling. A circular ring truss 14 at the center of the cross girder 13 may be provided with a rest space 18 overlooking the whole. Although not shown in the figure (a), the entrance 1 of the artificial ground truss 11 safety passage 17
Since 7a is located higher than the ground position, it is preferable to provide stairs. Further, as shown in FIG. 2B, when the artificial ground truss 11 is located in the underground part, the entrance 17
It is preferable to provide an approach ramp or stairs that goes down to a.

Next, the structure of the lining surface 12 laid on the upper surface of the artificial ground truss 11 will be described. This lining surface 1
2 is at the same level as the ground surface of the ground G when the artificial ground truss 11 is installed at a predetermined level in the ground as shown in FIG. 2B, so that the existence of the artificial ground 10 cannot be known from the outside. be able to. Therefore, the lining surface 12
Is a steel plate 12a having a predetermined withstand load and an artificial ground truss 1
No. 1 on each truss of No. 1 and the joints are waterproofed to prevent rainwater from entering the premises. It is preferable to use it as a ground such as by applying it. This can minimize discomfort with the surrounding ground and the environment. In consideration of the time of rainfall, the steel plate 12a of the lining surface 12 is provided with a drainage path capable of collecting water at the central portion or the peripheral edge with a predetermined rain gradient so that the rainwater and the like falling on the lining surface 12 can be replaced by the artificial ground truss 11 or It is preferable to drain to a peripheral drainage facility. In addition, it is also preferable to provide a predetermined water blocking seal on the peripheral edge of the artificial ground 10 so that rainwater does not enter the artificial ground 10 side from the surrounding ground.

The artificial ground truss 11 is supported by the pile head 30a of the support pile 30 via the jack 20 in the state shown in FIG. Although one center hole jack 20 and a rod 21 that meshes with the center hole jack 20 and bears a load are shown in the figure for simplification of the drawing, in reality, the entire artificial ground 10 is A plurality of jacks that can bear the own weight and the load are arranged. Further, in addition to the center hole jack type as shown in the drawing, a lifting device having a structure capable of vertically moving the entire artificial ground 10 such as a jack capable of moving up and down while engaging a part of shaped steel of a predetermined cross section. It is possible to use cylinder type jacks, airbag structures or any other type of lifting device. Further, although not shown, a level control device for adjusting the level when each jack is moved up and down is mounted so that the amount of lifting and lowering speed of each jack can be adjusted.

The steel sheet pile 31 shown in FIG. 1 (a) is used as a retaining wall for primary excavation. The primary excavation is performed to provide a continuous underground wall construction board G1 (GL.-3.5 m) used as a part of the main body structure as described later.

Next, referring to FIGS. 2 to 4, the artificial ground 10 will be described.
A procedure for constructing an underground parking lot P that is an underground structure while excavating under the artificial ground 10 will be described. A flow chart of the construction procedure is shown in FIG. 2, and a schematic construction drawing is also shown in FIGS. First, the artificial ground support pile 30 is constructed from the ground surface (GL.) At the outer peripheral position of the planar outer shape of the underground parking lot P (step 10).
0). The artificial ground support piles 30 are constructed at four locations on the outer circumference of the underground parking lot P as shown in FIG. 3 (1-b). Although cast-in-place piles are used in this embodiment, various piles such as steel pipes, PC driven piles and embedded piles can be constructed if a predetermined supporting force is obtained. Next, the steel sheet pile 31 is built over the entire circumference with a predetermined clearance outside the outer shape of the underground parking lot P (step 110). This steel sheet pile 31 is a retaining wall for the primary excavation for downgrading to the continuous wall construction board G1. In this embodiment, the primary excavation is GL. Since it is excavated up to -3.5 m, it is preferable to set a predetermined rooting length according to the geology of the excavated ground, and to provide an abdomen with an earth anchor or the like if necessary (Fig. 3 (2-a), (See (2-b)).

Then, the lifting jacks 20, the climbing rods 21 and the like are mounted on the pile heads 30a of the respective support piles 30 (step 120). Further, the artificial ground truss 11 is grounded so that the jack portion serves as a support point. A steel plate is laid on the upper surface of the artificial ground truss 11, and rainwater and the like that have fallen on the surface of the artificial ground 10 are collected to collect the artificial ground 10.
At the same time, construct drainage equipment for draining outside. From this state, the artificial ground truss 11 is jacked up by a predetermined amount to provide clearance for the primary excavation to the artificial ground truss 1.
1 (below step 130, FIG. 3 (3-a), (3
-B)).

Further, an approach ramp 32 for loading the excavating machine is provided under the artificial ground truss 11 to start the primary excavation. At this time, it is preferable to stretch a net fence 33 or the like around the artificial ground truss 11 to prevent a fall disaster or the like. Further, the safety passage 17 in the artificial ground truss 11 is opened so that the residents of the neighborhood can observe the situation of the primary excavation from above (step 140, FIG. 3 (4-a), (4-b). )reference).

After the completion of the primary excavation, the continuous underground wall 35 for the secondary excavation is constructed from the continuous wall construction board G1. This continuous underground wall 35 functions as a retaining wall for secondary excavation,
It is an RC connecting wall having a cylindrical shape used for the main structure, and its construction may be performed sequentially in the circumferential direction as shown in FIG. Construction may be performed at intervals, and then the subsequent element may be constructed (step 150, FIG.
a), (5-b)).

When the continuous underground wall 35 is completed, the artificial ground truss 11 is jacked down so that the top end of the lining surface 12 of the artificial ground 10 and the surrounding ground surface are at the same level (step 160). . In this state, the continuous underground wall 35
Once it reaches its desired strength, the continuous underground wall 3
RC wall 36 is built on the upper part of 5, and artificial ground truss 11
The support of the is piled up from the support pile 30 to the continuous underground wall 35.
At this time, it is preferable to perform load support by the support piles 30 in parallel until the strength of the RC wall body 36 is sufficiently obtained.

Further, various earthworking machines 3 for secondary excavation
7 is carried in, and an overhead crane 38 is installed on the lower surface of the artificial ground truss 11 to be used for carrying out excavated soil and carrying in materials. In addition, a loading gantry 39 for carrying out excavated soil
Alternatively, a vertical soil loading device 40 that can continuously carry out excavated soil may be provided along the continuous underground wall 35 as needed.
A loading yard and a loading device for carrying out the excavated soil may be provided near the outside of the continuous underground wall 35. Starting the secondary excavation from this state, the base plate G
L. The board is lowered to -32.0 m, and the excavation is completed (step 170, see FIG. 4 (6)).

Then, the main body work is started. First, the bottom board concrete 41 is poured, and then each floor is constructed. Of the main body structure, the bottom plate and side walls are constructed with reinforced concrete, but the approach ramps and parking spaces on each floor are constructed by sequentially assembling precast concrete, steel structure, or other composite structure. It is also possible to speed up. At this time, the overhead crane 38 is used for loading materials,
It is preferable to move vertically and horizontally along the arranged rail so that it can be moved to any position in the underground space (step 200, see FIG. 4 (7)).

As shown in FIG. 6, the construction of the parking lot is proceeded, and the basement 1st floor facility 43 having a permanent structure is constructed in the artificial ground truss 11 (step 210). At this time, if necessary, the temporary truss can be disassembled and the truss layout can be changed to form a permanent structure. In this case, it is preferable to calculate the structure of the entire truss separately at the time of temporary installation and at the time of permanent installation. It goes without saying that the artificial ground truss 11 may be designed with the permanent layout as a base from the beginning of the construction of the truss (step 210). Finally, an approach ramp 44 (see FIG. 5) that can directly enter the underground parking lot P from the surrounding road is constructed by a box culvert or the like as a permanent structure, and a series of construction is completed (step 220). As a result, it is possible to construct a large-scale underground parking lot in a short construction period with minimal impact on the ground functions.

In the present embodiment, an example of constructing an underground structure having a circular planar shape is shown, but it is possible to excavate an underground space having various polygonal planar shapes such as an oval or a rectangle according to the terrain. Needless to say. Further, the artificial ground truss can also be designed in various structural forms according to its scale and shape, and it is preferable to design not only the size of the truss and the dimensions of the steel material at the time of temporary installation but also considering the permanent structure. Further, the construction object is not limited to the underground parking lot, and the artificial ground can be effectively adopted when freely constructing an underground plant such as an underground warehouse, a transportation-related facility, a water supply and sewerage facility underground if necessary.

[0024]

As is apparent from the above description, according to the present invention, it becomes possible to secure the function of the existing ground facility and the environmental protection, and it is possible to achieve the construction in the area where the construction is conventionally difficult. Construction becomes possible, and restrictions and closures of ground functions at that time can be minimized. In addition, the construction will proceed without being affected by the weather, and since it will be installed as a permanent structure, it will be possible to eliminate the work of removing temporary construction, restoration work of the actual construction, etc., and shortening the construction period. It has the effect of being able to.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of an artificial ground of a method for constructing an underground structure using the artificial ground according to the present invention.

FIG. 2 is a construction flowchart showing an example of construction steps of a construction method for an underground structure using artificial ground according to the present invention.

FIG. 3 is a construction schematic diagram (1) of an underground parking lot constructed according to the construction procedure of FIG. 2.

FIG. 4 is a construction outline diagram (part 2) of an underground parking lot constructed according to the construction procedure of FIG. 2.

FIG. 5 is a plan view of a site showing a schematic plane of an underground parking lot constructed in this embodiment.

FIG. 6 is a schematic cross-sectional view of the underground parking lot shown in FIG.

[Explanation of symbols]

 10 Artificial ground 11 Artificial ground truss 12 Lining surface 13 Cross girder 17 Safety passage 20 Jack 30 Support pile 31 Steel sheet pile G Grand G1 Single wall construction board P Underground parking lot

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhisa Onouchi 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation

Claims (1)

[Claims] 1. An artificial ground pre-constructed on a ground surface to be excavated is supported by a lifting device, the ground immediately below the artificial ground is excavated to a predetermined depth, and the artificial ground is provided on a part of the excavated ground. The artificial ground is lowered to the support point position via the lifting device, the lining surface of the artificial ground and the ground surface of the excavation target are made to have substantially the same ground height, and the ground structure is subsequently excavated directly below the artificial ground. According to the artificial ground, characterized in that the underground space is formed by lowering to the foundation ground of, and then the underground structure is constructed in the underground space, and the artificial ground is left at the position. Construction method of underground structure.