JPH0553890B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is applicable to urban areas for water supply and sewage, public drainage, telegraph,
Concerning the open shield construction method for constructing underground structures such as underground passages for laying telephones, etc.

[Conventional technology]

The open shield construction method is a highly rational construction method that takes advantage of the advantages of the cut-and-cover construction method (open construction method) and the shield construction method.

The outline is shown in Figures 6 and 7. In the figure, 1 is an open shield machine, and this is the left and right side wall plate 1.
It consists of a, 1b and a bottom plate 1c connecting them,
This is a shield machine with openings on the front, rear, and top surfaces.

The open shield machine 1 has propulsion jacks 2 arranged vertically and facing rearward. 3 in the figure indicates a partition wall provided within the shield machine 1.

This shield machine 1 is installed in a starting shaft, and earth and sand in front of the starting shaft is excavated and discharged from the front or upper opening of the shield machine 1. Then, the propulsion jack 2 of the shield machine 1 is extended to apply a reaction force to the reaction wall in the launch shaft to move the shield machine 1 forward, and the first underground structure 4 made of a concrete box or the like is suspended from above. Down, tail part 1d of shield machine 1
Set it behind the propulsion jack 2 that has been retracted inside.

Next, earth and sand are similarly excavated from the front or upper surface of the shielding machine 1 using an excavating means 6 such as a shovel, an auger, or a bucket, and the earth is discharged to move the shielding machine 1 forward. First, the second underground structure 4 is suspended. Thereafter, the same excavation and setting process of the underground structures 4 is repeated to sequentially bury the underground structures 4 underground in columns, and backfill 5, Apply 5′,
When the oven shield machine 1 reaches the reaching hole, it is removed and the construction is completed.

[Problem to be solved by the invention]

In the open shield construction method using the open shield machine 1 as described above, the underground structure is directly suspended onto the bottom plate 1c of the tail part of the shield machine, and is then left underground as the shield machine 1 moves forward. It is something that will continue to be done. Therefore, a head difference is created by the thickness of the bottom plate 1c, which makes it difficult to compact the area below the bottom surface of the underground structure 4.

In addition, on the sides of the underground structure 4, when the underground structure 4 comes out from the tail part 1d, earth and sand is filled from above the ground between the ground and the underground structure 4. ', but this part is too narrow for workers to enter, and is long enough both vertically and vertically. Therefore,
The backfill 5' may not be sufficiently compacted and may become loose.

The purpose of the present invention is to eliminate the disadvantages of the conventional example,
The open shield construction method allows you to easily stabilize the ground below, on the sides, and above the installation of underground structures without any troublesome work, prevent subsidence or displacement of underground structures, and improve water-stopping performance. Our goal is to provide the following.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention provides a propulsion jack in a shield machine with openings at the front and rear ends and the top surface, excavates from the front surface or the top surface of the front part of the shield machine, and applies reaction force to existing underground structures such as a following box. The shield machine is moved forward using the propulsion jack, and as the shield machine moves forward, a new underground structure is lowered from the top of the rear part of the shield machine and placed in the front row of the existing underground structure, and the same process is repeated to complete the shield. In the open shield construction method, in which the machine excavates and backfills the top and side surfaces of existing underground structures in tandem, the shield machine connects the lower ends of the side wall plates with a bottom plate, but the bottom plate is extended to the tail part. The bottom surface of the tail part is an opening with no bottom plate, and the underground structure has a bottom plate,
The side wall plates and top plate shall have backfill grout holes, and crushed stone will be laid in a layer under the bottom of the underground structure, and cement milk will be poured from inside the underground structure into the crushed stone layer through the grout holes in the bottom plate. Then, the propulsion jack is extended to push the shield machine forward, and as the shield machine advances in this way, the concrete floor and underground structure are placed in the tail part of the shield. Once the underground structure is out of the way, it is recommended to backfill the void around the underground structure from the ground level and completely bury it, then pour out cement milk through the grout hole and backfill the sides and top with grout. This is a summary.

[Effect]

According to the present invention, an installation floor of an appropriate level is formed in the tail portion of the shielding machine using concrete made of crushed stone and cement milk and is highly waterproof, and the underground structure is placed on this installation floor.

In addition, after the shield machine moves forward and the underground structure comes out behind the shield machine, the cement milk permeates into the backfilling earth and sand on the sides of the underground structure and backfill grout is performed. It prevents the backfilling earth and sand on the sides of medium-sized structures from loosening and provides water-stopping properties.

Furthermore, the same applies when cement milk is poured into the backfilling portion of the upper surface of an underground structure.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

First, the underground structure used in the construction method of the present invention will be explained.

An example of this is shown in FIGS. 4 and 5. The underground structure 4 is made of a concrete box as in the past, and grout holes 7 for backfilling are formed in the wall from the inside to the outside as appropriate. A few were formed.

This grout hole 7 is located in the bottom plate 4c of the underground structure 4.
shall be provided on the side wall plate 4b and the top plate 4a,
It can be closed from the inside with a stopper 8.

Next, the construction method of the present invention will be explained.

Fig. 1 is a longitudinal sectional side view showing one embodiment of the construction method of the present invention, Fig. 2 is a transverse plan view of the same, and Fig. 3 is a longitudinal sectional rear view of the same, which are the same as Figs. 6 and 7 showing the conventional example. Components are given the same reference numerals.

Regarding the open shield machine 1 used in this embodiment, the left and right side wall plates 1a and 1b are the same as the conventional ones, and the lower ends of these side wall plates 1a and 1b are connected to each other by a bottom plate 1c, and the partition wall 3 and the Although omitted, it is assumed that the upper part thereof is connected by a beam member and the front, rear and upper surfaces are open, but the bottom plate 1c does not extend to the tail part 1d of the shield machine 1, and is The lower surface is an opening with the bottom plate 1c missing.

In addition, propulsion jacks 2 are arranged vertically and facing rearward at intermediate positions between the front and back inside the side wall plates 1a and 1b, and a support rod 11 made of box steel or shaped steel is attached to the rear end.

Furthermore, as another embodiment of the shield machine 1, the side wall plates 1a and 1b are connected to each other at a predetermined interval by beam members, but the bottom plate 3 is omitted, and the shield machine 1 has not only the front and top surfaces but also the bottom surface. All of them may be open.

Earth and sand are excavated from the front or upper surface of the shield machine 1 by the excavating means 6 and removed. The propulsion jack 2 is placed in contact with the front end of the existing underground structure 4 by pressing the pusher 11.
is extended to move the shield machine 1 forward.

Next, the propulsion jack 2 is retracted and the push rod 1 is
1 is moved to the front part within the tail part 1d, the ground is exposed under the tail part 1d, so crushed stones 13 are laid on top of it and leveled in layers.

At this time, the underground structure 4 can be placed at an appropriate height by adjusting the height of the crushed stone 13 according to the height of the existing installation floor at the rear.

Then, a new underground structure 4 is suspended from above within the tail portion 1d and set at the forefront of the existing underground structure 4.

Next, when cement milk 9 is poured from inside the underground structure 4 onto the crushed stones 13 using the grout hole 7 of the bottom plate 4c, the cement milk 9 enters between the crushed stones 13 and fills them. Crushed plate 1
A concrete installation floor 15 using No. 3 as aggregate is formed. The underground structure 4 is placed on this installation floor 15.

At this stage, plugs 8 are applied to unnecessary grout holes 7 in the side wall plate 4b, top plate 4a, etc. to close them.

Next, the propulsion jack 2 is extended to push the shield machine 1 forward to form a new concrete installation floor 15, and a new underground structure 4 is set thereon in the tail portion 1d. In this way, shield machine 1
When the concrete installation floor 15 and the underground structure 4 move forward, the concrete installation floor 15 and the underground structure 4 come out from the tail part 1d of the shield machine 1 and remain underground, and a void is formed on the left and right of the underground structure 4, but this void Backfilling 5' is carried out from above the ground in the same manner as in the conventional example shown in FIG.

Backfilling 5 is also performed on the upper surface of the underground structure 4 in the same manner.

After the underground structure 4 is completely buried in this way, cement milk 9 is poured into the backfill 5' from the grout hole 7 of the side wall plate 4b on the side.
Perform backfill grouting.

The backfill 5 on the top surface of the underground structure 4 will become stable if it is compacted one by one, but if necessary, cement milk 9 may be added to the backfill 5 using the grout hole 7 of the top plate 4a. It is also possible to pour out and backfill grout.

〔Effect of the invention〕

As described above, the open shield construction method of the present invention performs grouting in two stages depending on the condition of the shield machine, and as the first stage grouting, a concrete installation floor is placed under the underground structure inside the shield machine. Because it can be formed, underground structures can always be set in the correct position.

Furthermore, the concrete installation floor serves as a water stop layer, and after the shield machine advances, the sides and top of the underground structure that comes out from the shield machine are backfilled and then grouted around it, so the ground is stabilized, and Since work can be easily performed from inside the underground structure without any troublesome effort, it is possible to prevent the underground structure from sinking or shifting, and to achieve reliable construction.

[Brief explanation of the drawing]

Figure 1 shows the first example of the open shield construction method of the present invention.
FIG. 2 is a cross-sectional plan view of the same as above, FIG. 3 is a longitudinal rear view of the same as above, FIG. 4 is a partially cutaway front view of the underground structure, FIG. 5 is a bottom view of same as above,
FIG. 6 is a vertical cross-sectional side view showing a conventional example, and FIG. 7 is a cross-sectional plan view of the same. 1...Open shield machine, 1a, 1b...Side wall plate, 1c...Bottom plate, 1d...Tail part, 2...
Propulsion jack, 3... bulkhead, 4... underground structure,
4a...Top plate, 4b...Side wall plate, 4c...Bottom plate, 5, 5'...Backfilling, 6...Excavation means, 7...
... Grout hole, 8 ... Plug, 9 ... Cement milk, 11 ... Pressure lumber, 13 ... Crushed stone, 15 ... Concrete installation floor.

Claims (1)

[Scope of Claims] 1. A propulsion jack is provided in a shield machine with openings at the front and rear ends and the top surface, and excavation is carried out from the front surface or the top surface of the front part of the shield machine, and the propulsion jack is used as a reaction force from an existing underground structure such as a following box. Move the shield machine forward, use this forward movement to lower the new underground structure from the upper surface of the rear part of the shield machine, position it in the front row of the existing underground structure, and repeat the same process to advance the shield machine. In addition, in the open shield construction method where the top and side surfaces of existing underground structures arranged in tandem are appropriately backfilled, the shield machine connects the lower ends of the side wall plates with a bottom plate, but the bottom plate does not extend to the tail part. The lower surface of the tail section shall be an opening with no bottom plate, and the underground structure shall have backfill grout holes in the bottom plate, side wall plate, and top plate, and crushed stone will be laid in a layer under the bottom of the underground structure. At the same time, cement milk is poured from inside the underground structure into the crushed stone layer through the grout hole in the bottom plate to form a concrete installation floor using crushed stone as aggregate.Then, the propulsion jack is extended to push the shield machine forward. When the shield machine moves forward and the concrete installation floor and underground structure come out from the tail of the shield machine, the gap around the underground structure is backfilled from the ground and completely buried. An open shield construction method characterized by pouring cement milk through the grout hole and backfilling the sides and top with grout.