JP2732014B2 - Construction method of large section underground structure by open shield method. - Google Patents

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 having a large section by an open shield method.

[0002]

2. Description of the Related Art As is well known, the open shield method is
This is a highly rational construction method that takes advantage of the open-cutting method (open method) and the shield method.

[0003] First, the open shield method will be described. As shown in FIGS. 6 and 7, reference numeral 1 denotes an open shield machine, which comprises left and right side wall plates 1a and 1b and these side wall plates 1a and 1b.
This is a shield machine having a front surface, a rear surface, and an upper surface, each of which has a length approximately equal to a and 1b and a bottom plate 1c connecting between them. The open shield machine 1 forms the tip of the side walls 1a, 1b and the bottom plate 1c as a cutting edge 2, and further includes the side wall plates 1a, 1b.
A plurality of propulsion jacks 3 are arranged vertically upward and rearward near the center or the rear end of 1b.

[0004] In the drawing, reference numeral 7 denotes a pressing member provided at the rear end of the propulsion jack 3, which is made of a frame made of box steel or die steel. In the figure, reference numeral 8 denotes a partition wall which partitions a front excavation portion and a rear portion in the open shield machine 1.

[0005] The open shield method is carried out between a starting pit and a reaching pit. Although not shown, the open shield machine is assembled in the start pit, the ground in front of the start pit is excavated by the excavator 6, the propulsion jack 3 of the shield machine 1 is extended, and a reaction force is applied to the reaction wall in the start pit. , The shield machine 1 is moved forward, the first concrete box 4 forming the underground structure is suspended from above, and the tail part 1d of the shield machine 1 is taken down.
It is set behind the propulsion jack 3 that has shrunk inside. A strut is arranged between the propulsion jack 3 and the reaction wall to adjust the distance as appropriate. The starting pit is composed of a retaining wall such as a sheet pile, and the retaining wall is partially mirror-cut in order to start the open shield machine 1. Some improvements have been made.

Next, similarly, the excavator 6 excavates earth and sand from the front or upper surface of the shield machine 1 and discharges the earth to advance the shield machine 1, so that the second machine is provided before the first concrete box 4. Is suspended in the tail part 1d of the shield machine 1. Hereinafter, the same excavation and setting steps of the concrete box 4 are repeated, and the concrete boxes 4 are sequentially buried in the ground in a column, and backfill 5 is performed on the rear concrete box 4, and illustration is omitted. When the open shield machine 1 reaches the destination pit, it is disassembled and removed to complete the construction.

[0007]

As described above, in the open shield method, the size of the cross section of the underground structure to be constructed is determined by the size of the open shield machine to be used and the size of the concrete box to be suspended. Because of the lack of a machine, it was considered unsuitable for the construction of large underground structures.

[0008] An object of the present invention is to solve the inconvenience of the conventional example and to provide a method of constructing a large cross-section underground structure by an open shield method which can easily and safely construct a large cross-section underground structure. is there.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a step of excavating and discharging earth and sand in front of an opening of a front or upper surface of an open shield excavator, and extending a propulsion jack to form a concrete box. The step of advancing the open shield excavator by the reaction force, and a new concrete box is suspended from above and set behind the propelled jack shrunk in the tail of the open shield excavator, and this is set in the existing concrete box. Using the open shield method, in which concrete boxes are buried in tandem in order to form an underground structure, repeating the process of connecting to the body as needed, the preceding underground structure with multiple columns of concrete boxes at intervals And then excavating between the preceding underground structures using the preceding underground structures formed by the columns of these concrete boxes as retaining walls. The construction of the concrete underground structure skeleton of the central part connecting the preceding underground structures to each other and the construction of the preceding underground structure by cascading multiple rows of concrete boxes are performed simultaneously, The gist of the present invention is that the excavation during the construction of the object and the construction of the concrete skeleton in the central portion are sequentially advanced backward according to the construction of the columns of the plurality of concrete boxes.

[0010]

According to the first aspect of the present invention, the underground structure can be quickly and easily constructed by the open shield method utilizing the advantages of the open-cut method (open cut method) and the shield method. It is possible to construct, furthermore, excavate between the columns of the concrete box by using the columns of the concrete box by this open shield method as a retaining wall, and construct the concrete underground structure skeleton of the central part connecting the columns of these concrete boxes to each other. If constructed, an underground structure with a large cross section can be easily obtained as a whole without the need for additional temporary earth retaining support.

According to the second aspect of the present invention, in addition to the above operation, the construction can be performed more quickly without providing time between steps.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a plan view showing a method of constructing a large-section underground structure by the open shield method of the present invention, and FIGS. 2 to 5 are vertical sectional front views of the respective steps.

According to the present invention, the preceding underground structures 9 are firstly constructed at intervals by arranging concrete boxes in the open shield method. The construction method of the preceding underground structure 9 is as described above with reference to FIGS.

That is, there is used a shield machine 1 having left and right side walls 1a, 1b and a bottom plate 1c having the same length as the side walls 1a, 1b and connecting them, and having open front, rear and top surfaces. The open shield machine 1 forms the tip of the side walls 1a, 1b and the bottom plate 1c as a cutting edge 2,
In addition, a plurality of propulsion jacks 3 are arranged vertically rearward near the center or near the rear end of the side wall plates 1a, 1b.

In the figure, reference numeral 7 denotes a pressing member which is suspended from above at the rear end of the propulsion jack 3 and is composed of a frame made of box steel or die steel. In the figure, reference numeral 8 denotes a partition wall which partitions a front excavation portion and a rear portion in the open shield machine 1.

Although not shown, the open shield machine 1 is assembled in the start pit, the ground in front of the start pit is excavated by the excavator 6, the propulsion jack 3 of the shield machine 1 is extended, and the reaction wall in the start pit is extended. The shield machine 1 is moved forward by taking a reaction force, the first concrete box 4 forming the underground structure is suspended from above, and the rear of the propulsion jack 3 contracted in the tail part 1d of the shield machine 1 Set to. Propulsion jack 3
A strut is arranged between the and the reaction wall to adjust the distance as appropriate. The starting pit is composed of a retaining wall such as a sheet pile, and the retaining wall is partially mirror-cut in order to start the open shield machine 1. Some improvements have been made.

Next, similarly, the excavator 6 excavates earth and sand from the front or upper surface of the shield machine 1 and discharges the earth to move the shield machine 1 forward. Is suspended in the tail part 1d of the shield machine 1. Hereinafter, the same excavation and the setting process of the concrete box 4 are repeated, and the concrete boxes 4 are sequentially buried in the ground in a column. In this manner, the preceding underground structures 9 composed of the columns of the concrete boxes 4 are constructed at intervals by the open shield method.

When the concrete box 4 is suspended in the tail portion 1d of the excavator 1, the concrete box 4 is interconnected and integrated with the existing concrete box 4, but this connection is made by using a screw steel rod. A method of inserting the steel wire into the sheath hole provided in the concrete box 4 and fastening with a nut, a method of inserting a PC steel wire, applying a prestress with a jack, and then tightening with a fixing tool can be adopted.

As shown in FIG. 2, a space between the columns of the concrete boxes 4 is excavated (root cutting) using the preceding underground structure 9 formed by the columns of the concrete boxes 4 in the open shield method as a retaining wall.

In this case, the cascading concrete box 4 may be used as a work bench for excavation, and an excavator or the like may be arranged on this work bench. Further, a lining plate may be laid over the upper surfaces of the opposing concrete boxes 4 to serve as a work table.

When the root is cut, the preceding underground structure 9 functions as a retaining wall. However, as the root cutting progresses, an earth anchor 13 and the like are provided on the concrete box 4 as necessary. This may increase the supporting force. Further, a cutting beam or the like may be arranged at the excavated portion.

The concrete underground structure body 10 at the central portion connecting these parallel preceding underground structures 9 to each other
To construct.

As shown in FIG. 4, the concrete underground structure skeleton 10 is first provided with a discarded stone or discarded concrete at the root incision, and after arranging reinforcement thereon, concrete is poured.
A concrete floor slab 11 is provided. This concrete floor slab 11
Is connected to a reinforcing bar to be connected to a joint reinforcing bar protruding from the wall surface of the concrete box 4 and integrally connected to the preceding underground structure 9.

Further, as shown in FIG. 5, a top plate (upper floor plate) 12 is laid over the upper surfaces of the opposing concrete boxes 4 to construct the concrete underground structure frame.
Complete 10 The top plate 12 may be formed from a cast-in-place concrete with a formwork, but a precast concrete plate may be used.

In addition, a locking ridge 14 may be provided in advance on the upper surface of the concrete box 4 in order to easily receive the top plate 12 made of such a precast concrete plate.

The excavation (root cutting) between the preceding underground structures 9 and the formation of the concrete underground structure body 10 by the concrete slab 11 and the top plate 12 are performed by the columns of the concrete box 4 by the open shield method. It may be performed after all the design lengths of the preceding underground structure 9 have been constructed, but it is also possible to proceed sequentially according to the formation of the preceding underground structure 9.

For example, if the preceding underground structure 9 is constructed for several meters or several tens of meters, the excavation (root cutting) and the formation of the concrete underground structure body 10 are performed several meters shorter than the end, and then the preceding underground structure 9 It is also possible to extend the construction length in such a way as to extend the construction length by repeating the excavation (root cutting) and the formation of the concrete underground structure skeleton 10.

[0028]

As described above, the method for constructing an underground structure having a large cross section by the open shield method according to the present invention is capable of easily and safely constructing an underground structure having a large cross section in a short time.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a construction method of a large-section underground structure by an open shield method according to the present invention.

FIG. 2 is a vertical sectional front view of a first step showing one embodiment of a construction method of a large-section underground structure by the open shield method according to the present invention.

FIG. 3 is a vertical sectional front view of a second step showing one embodiment of the construction method of the large-section underground structure by the open shield method of the present invention.

FIG. 4 is a vertical sectional front view of a third step showing one embodiment of the construction method of the large-section underground structure by the open shield method of the present invention.

FIG. 5 is a vertical sectional front view of a fourth step showing one embodiment of the construction method of the large-section underground structure by the open shield method of the present invention.

FIG. 6 is a vertical sectional side view of the open shield method.

FIG. 7 is a cross-sectional plan view of the open shield method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Open shield machine 1a, 1b ... Side wall plate 1c ... Bottom plate 1d ... Tail part 2 ... Blade opening 3 ... Propulsion jack 3a ... Base 4 ... Concrete box 5 ... Backfilling 6 ... Excavator 7 ... Pressing member 8 ... Partition wall 9 … Preceding underground structure 10… concrete underground structure skeleton 11… concrete floor slab 12… top plate 13… earth anchor 14… locking pier

Claims (2)

(57) [Claims] A step of excavating and discharging earth and sand in front of the front or upper surface opening of the open shield machine, a step of extending the propulsion jack and advancing the open shield machine with a reaction force of the concrete box, The process of hanging a new concrete box from above and setting it to the existing concrete box behind the propelled jack shrunk in the tail section of the open shield machine and connecting it to the existing concrete box is repeated as necessary. The underground structure is constructed by arranging multiple columns of concrete boxes at intervals using the open shield method of burying them in columns to form an underground structure. With the structure as a retaining wall, excavation is made between the preceding underground structures, and then the center part connecting these parallel preceding underground structures is connected. Construction method of large section underground structure by open shield method characterized by construction of concrete underground structure frame. 2. Construction of a preceding underground structure by arranging a plurality of rows of concrete boxes in parallel is performed simultaneously, and excavation between the construction of the preceding underground structure and construction of a concrete body in a central portion are performed by the plurality of rows of concrete boxes. The method of constructing a large-section underground structure by the open shield method according to claim 1, wherein the structure is sequentially advanced rearward according to the construction of the columns of the boxes.