JPH05295736A - Open shield method and machine therefor - Google Patents

Abstract

PURPOSE:To preclude back-fill earth and sand in the open shield method from flowing to inside of an open shield machine when back filling is made to the excessively excavated part while works are executed in a sand/grit layer or curbing is performed. CONSTITUTION:A flexible board 9 whose front extremity 9a is fixed while the rear extremity 9b is hopped out laterally about an open shield machine 1 so as to approach the wall of an excavation hole, is mounted vertically outside of the tips of the left and right side wall plates 1a, 1b of the open shield machine. Back filling 8 is made in the outside area of these side wall plates 1a, 1b situated behind the flexible board 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an open shield construction method for constructing underground structures such as water supply and sewerage, common ditches, telegraphs, telephones, and other underground passages, and an open shield machine used therefor.

[0002]

2. Description of the Related Art The open shield construction method is a rational construction method that takes advantage of the advantages of the open-cut construction method (open construction method) and the shield construction method.

The outline is shown in FIGS. 3 to 6, in which 1 is an open shield machine, which is a left and right side wall plate 1a, 1b.
And a side plate 1a, 1b and a bottom plate 1c having the same length and connecting the side plates 1a and 1b. The open shield machine 1 has the side walls 1a, 1b and the bottom plate 1c formed with the tips as blade openings 2.
Further, the propulsion jacks 3 are arranged vertically side by side near the center or near the rear ends of the side wall plates 1a and 1b.

Reference numeral 7 in the drawing denotes a pressing member provided at the rear end of the propulsion jack 3, which is a frame body made of box steel or shaped steel.

The propulsion jack 3 of the shield machine 1 is extended and a reaction force is applied to the reaction force wall in the start pit 6 to advance the shield machine 1 to move the first concrete box 4 forming an underground structure. Suspended from above, the tail part 1d of the shield machine 1
Set it behind the propelling jack 3 that has been contracted inside. Struts are arranged between the propulsion jack 3 and the reaction wall to adjust the distance as appropriate. Further, the start pit 6 is composed of a retaining wall such as a sheet pile. To start the open shield machine 1, a part of this retaining wall is cut into a mirror. The ground may be improved on the ground.

Then, similarly, the earth and sand are excavated from the front surface or the upper surface of the shield machine 1 and the soil is discharged to move the shield machine 1 forward, so that the second underground structure is placed in front of the first underground structure 4. The structure 4 is suspended in the tail portion 1d of the shield machine 1.
Hereinafter, the same excavation and setting process of the underground structure 4 is repeated to sequentially embed the underground structure 4 in the column, and backfill the rear underground structure 4 as shown in FIG. Although not shown in the figure, if the open shield machine 1 reaches the reaching pit, it is removed and the construction is completed.

In this way, the underground structure 4 is sequentially left behind from the tail portion 1d of the shield machine 1 and buried in the ground as the open shield machine 1 is dug. The space between the underground structure 4 and the open shield machine 1 is filled with water glass-based grout material 20, and the underground structure 4 has a grout material on the outer periphery except for the upper surface.
It is left in the ground as wrapped in 20.

[0008]

With such an open shield machine 1, excavation is performed from the ground surface between the inside of the blade mouth 2 and the front portion, so the earth and sand at the blade front portion loosen and the ground is displaced. .. When excavating the gravel layer, the earth and sand on the outer peripheral portion of the blade tip 2 is dug out, and the excavation hole width widens by that amount, and a gap is formed between the excavation hole wall and the side walls 1a and 1b of the open shield machine 1. Will occur.

A so-called backfilling 8 for replenishing earth and sand from the above-ground portion is performed in this gap. However, open shield machine 1
At the time of advancing, the backfill earth and sand is dragged, bypasses the blade opening 2 and flows into the inside of the open shield machine 1, and it is useless to backfill.

The phenomenon of the above-mentioned overburden occurs not only in the gravel layer but also in the case where the open shield machine 1 is bent and advanced in the curve construction. By the way, for curve construction, shield machine 1
The strokes of the propulsion jacks 3 arranged on the left and right inside are different and the shield machine 1 is bent and moved forward.

An object of the present invention is to solve the disadvantages of the conventional example and to prevent the backfilled earth and sand from flowing into the inside of the open shield machine when backfilling the overburden portion. It is to provide a construction method and an open shield machine.

[0012]

In order to achieve the above-mentioned object, the present invention provides a propulsion jack inside the left and right side wall plates,
A step of excavating and discharging earth and sand in front of the front or upper surface opening of the open shield machine having the front, rear surface and upper surface opened,
The process of extending the propulsion jack and making the concrete box a reaction force to advance the shield machine, and the step of suspending and setting a new concrete box from above behind the propulsion jack contracted in the tail part of the shield machine. In the open shield method of sequentially burying concrete boxes in vertical rows by repeating and, the front end can be fixed and the rear end can be ejected to the side of the open shield machine so that it is close to the borehole wall. The gist of the present invention is to attach the flexible plates vertically to the outer side of the left and right side wall plates of the open shield machine, and to refill the outside of the left and right side wall plates of the open shield machine behind the flexible plate.

[0013]

According to the present invention, the backfill earth and sand on the outside of the left and right side wall plates of the open shield machine is not blocked by the flexible plate and bypasses the tips of the left and right side wall boards and flows into the inside of the open shield machine. ..

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 is a cross-sectional plan view showing an embodiment of an open shield construction method and an open shield machine of the present invention, FIG.
3 is a side view with a part cut away, showing the conventional example shown in FIG.
The same components as those in FIG. 6 are designated by the same reference numerals.

The open shield machine 1 includes left and right side wall plates 1.
a U-type shield machine having front, rear and upper surfaces formed by a and 1b and a bottom plate 1c having the same length as the side plates 1a and 1b and connecting the side plates 1a and 1b, and the center or rear end of the side plates 1a and 1b. It is the same as the conventional example that the propulsion jacks 3 are arranged side by side in the vertical direction and are arranged vertically, and the pressing member 7 is provided at the rear end.

According to the present invention, a strip-shaped flexible plate 9 made of a rubber plate or the like is vertically attached near the outer ends of the left and right side wall plates 1a and 1b of the open shield machine 1. The flexible plate 9 has a front end 9a fixed at appropriate intervals with bolts or the like, is provided with a bend, and has a rear end 9b protruding laterally from the open shield machine 1.

Next, an open shield construction method using the open shield machine 1 will be described. The overall outline is the same as in the conventional example, the shield machine 1 is started from the start pit, the earth and sand are excavated from the front surface or the upper surface of the shield machine 1, and the soil is discharged to remove the first underground structure 4 The tail part 1d of the shield machine 1 is attached to the second underground structure 4 before.
Suspend inside. Hereinafter, the same excavation and setting process of the underground structure 4 are repeated to sequentially bury the underground structures 4 in a column, and backfill the rear underground structure 4 to open the open shield machine 1. When reaches the reach pit, remove this and complete the construction.

In the open shield machine 1 as described above, excavation is performed from the ground surface between the inside of the blade mouth 2 and the front portion as described above, so the earth and sand at the front portion of the blade mouth are loosened and the ground is displaced. .. And, when excavating the gravel layer or in the case of curve construction even on the ordinary ground, the earth and sand on the outer peripheral portion of the blade mouth 2 is dug up,
The width of the excavation hole is widened accordingly, and a gap is created between the excavation hole wall and the side walls 1a and 1b of the open shield machine 1.

When such a gap is generated, the flexible plate 9 is used.
Flutters to the side of the open shield machine 1 so that the rear end 9b approaches or abuts against the borehole wall.

Therefore, backfilling 8 is performed in the gap between the excavation wall behind the flexible plate 9 and the left and right side walls 1a, 1b.
The flexible plate 9 separates the portion where the backfilling 8 is performed and the front of the open shield machine 1.

Even when the open shield machine 1 is moved forward in this state, since the flexible plate 9 remains, the earth and sand of the backfill 8 is blocked by the flexible plate 9 and bypasses the tips of the left and right side wall plates 1a, 1b. Therefore, it does not flow into the open shield machine 1.

When the ground is not a gravel layer,
If the curve construction is not carried out even on the normal ground, there will be no excess trench, so the rear side end 9b of the flexible plate 9 will be the left and right side walls 1a, 1a.
Folded so as to overlap with b, and proceed in this state.

[0023]

As described above, the open shield method and the open shield machine of the present invention can be used for backfilling in a gravel portion when performing backfilling in a gravel layer or in a curve. It is possible to prevent sediment from flowing inside the open shield machine.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view showing an embodiment of an open shield construction method and an open shield machine of the present invention.

FIG. 2 is a partially cutaway side view showing an embodiment of an open shield construction method and an open shield machine of the present invention.

FIG. 3 is a vertical sectional side view of a conventional open shield machine.

FIG. 4 is a cross-sectional plan view of a conventional open shield machine.

FIG. 5 is a vertical sectional side view showing an outline of an open shield construction method.

FIG. 6 is a cross-sectional plan view showing an outline of an open shield construction method.

[Explanation of symbols]

 1 ... Open shield machine 1a, 1b ... Side wall plate 1c ... Bottom plate 1d ... Tail part 2 ... Blade part 3 ... Propulsion jack 4 ... Underground structure 5 ... Backfilling 6 ... Start pit 7 ... Pressing member 8 ... Backfilling 9 ... Flexible plate 9a ... Front end 9b ... Rear end 20 ... Grout material

Claims (2)

[Claims] 1. A step of digging and discharging earth and sand in front of an opening or a front surface of an open shield machine having front, rear and upper surfaces provided with propulsion jacks inside right and left side wall plates, and extending the propulsion jack. Repeat the process of moving the shield machine forward by using the concrete box as a reaction force and the step of suspending and setting a new concrete box from above behind the propulsion jack that has been compressed in the tail part of the shield machine. In the open shield method of sequentially burying concrete boxes in a vertical column, the flexible plate was fixed at the front end and was pushed out to the side of the open shield machine so that the rear end was close to the borehole wall. The vertical shield is attached to the outside of the left and right side wall plates of the open shield machine, and the outside of the left and right side wall plates of the open shield machine that is behind this flexible plate is backfilled. Punshield construction method. 2. In an open shield machine in which propulsion jacks are arranged inside the left and right side wall plates and the front, rear and top surfaces are opened, the front end is fixed and the rear end is splashed to the side of the open shield machine. The open shield machine is characterized in that the flexible plates that have been taken out are vertically attached to the outer ends of the left and right side wall plates of the open shield machine.