JPH0762436B2 - 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 an open shield construction method for constructing underground structures such as laying underground passages such as water and sewers, common ditches, telegraphs and telephones in urban areas.

[0002]

2. Description of the Related Art The open shield construction method is a highly rational construction method that takes advantage of the advantages of the open cut construction method (open cut 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 shield having a front surface, a rear surface and an upper surface which are composed of left and right side wall plates 1a and a bottom plate 1b connected to these side wall plates 1a. It is a machine. In the open shield machine 1, the tip ends of the side wall plate 1a and the bottom plate 1b are formed as the blade openings 2, and the propulsion jacks 3 are arranged vertically rearward near the center or the rear end of the side wall plate 1a.

As shown in FIG. 3, the open shield machine 1 is installed in the launch pit 8 and the propulsion jack 3 of the shield machine 1 is extended to apply a reaction force to the reaction wall 9 in the launch pit to shield the shield. The machine 1 is moved forward, the first concrete box 4 forming the underground structure is suspended from above, and is set behind the propulsion jack 3 compressed in the tail portion of the shield machine 1. In the figure, reference numeral 10 denotes a strut, which is arranged between the propulsion jack 3 and the reaction force wall 9 for appropriately adjusting the gap. Further, the start pit 8 is composed of a retaining wall. To start the open shield machine 1, a part of this retaining wall is cut into mirrors, but if necessary, ground improvement is performed in front of the start pit 8 by injecting a chemical solution or the like. May be given.

Then, the excavator 6 such as a shovel excavates earth and sand from the front surface or the top surface of the open shield machine 1 and discharges it. Simultaneously with or after this soil discharging step, the propulsion jack 3 is extended to advance the shield machine 1. In the case of this advancing process, a pushing angle 7 made of a frame body made of box steel or shaped steel is arranged in front of the concrete box 4. Then, before the first concrete box 4, the second concrete box 4 is suspended in the tail portion of the shield machine 1. Hereinafter, the same soil discharging step, advancing step, and setting step of the concrete box 4 are appropriately repeated to sequentially leave the concrete box 4 in the ground in a row along with the forward movement of the open shield machine 1, and further to this concrete box. Backfill 5 is applied to the upper surface of 4, and pavement 12 is applied to the surface.

In this way, when the open shield machine 1 reaches the reaching pit 13, it is removed and the construction is completed.

[0006]

In such an open shield construction method, as described above, the concrete box 4 is
It is suspended in the tail portion of the shield machine 1 and, as the open shield machine 1 moves forward, exits from the tail portion and remains in the ground. The concrete box 4 is made of reinforced concrete with reinforcing bars 14 as shown in FIG. The concrete box 4 receives a reaction force when the propulsion jack 3 is extended to move the shield machine 1 forward, but even though the pushing angle 7 is arranged at the front part, a considerable load is applied to the front end thereof. , This part is split and destroyed,
Easy to crack.

In particular, when performing a curve construction, the shield machine 1 is bent and moved forward while the strokes of the propulsion jacks 3 arranged on the left and right inside the shield machine 1 are made different, and the concrete box 4 is also moved left and right. Since uneven loads are applied, cracks are more likely to occur.

Further, the concrete box 4 is connected to the rear concrete box 4 by a steel rod or the like, but a sealing material is arranged on the joint surface for stopping water. But the propulsion jack 3
If there is an unbalanced load due to, the sealing material may be broken, and as the diameter of the underground structure to be constructed becomes larger, the diameter of the concrete box 4 also becomes larger and the sealing material completely Stopping water is also difficult.

Further, although a steel collar may be arranged at the joint between the concrete boxes 4, it is very troublesome to install the steel collar in the limited space in the shield machine 1. Therefore, workability is poor. Further, the use of such a steel collar is limited to the case of the concrete box 4 having a relatively small diameter.

The object of the present invention is to eliminate the disadvantages of the above-mentioned conventional example, to prevent the occurrence of cracks in the concrete box even when receiving the load for pushing out by the propulsion jack, and to prevent the concrete boxes from interlocking with each other. The purpose of the present invention is to provide an open shield method that can be used to construct a highly reliable underground structure that can easily and completely carry out water with a large cross section.

[0011]

DISCLOSURE OF THE INVENTION The present invention excavates earth and sand in front of the front or top opening of an open shield machine in which a propelling jack is arranged inside the left and right side wall plates and the front, rear and top surfaces are opened. And the process of extending the propulsion jack to make the concrete box a reaction force to advance the shield machine, and suspending a new concrete box from above behind the propulsion jack contracted in the tail part of the shield machine. In the open shield construction method in which the concrete box is sequentially buried in the column by repeating the setting process, the concrete box is made of reinforced concrete and consists of left side plate, right side plate, upper floor plate and lower floor plate. , The front and rear faces are openings, and both sides of the front and rear end faces, which are the faces of the openings, or front end faces are made of thin plates that have almost the same shape as the front and rear end faces of the concrete box. The plate has an anchor and is attached so as to be integrated with the concrete box, and the propulsion jack load is applied to the attached part of this steel sheet, and the front end of the concrete box connected to each other. The gist of the surface and the rear end surface is that the peripheral edges of the steel plates are welded to each other to seal them in a watertight manner.

[0012]

According to the present invention, since the front and rear end faces, which are the opening faces, of the concrete box are protected and covered by the steel plate, the rigidity is increased by the steel plates and the load for pushing out by the propulsion jack is applied to the side of the opening face. However, it is possible to prevent the occurrence of cracks.

Further, since the steel plates come into contact with each other when connecting the concrete boxes, the peripheral edges of the steel plates can be welded to each other from the outside of the concrete box to seal them in a watertight manner, and the waterproofness is high. It can be a connection box.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. First, the concrete box used in the method of the present invention will be described. As shown in FIG. 1, the concrete box 4 is made of reinforced concrete, and the left side plate 4
a, a right side plate 4b, an upper floor plate 4c and a lower floor plate 4d, the front and rear surfaces of which are openings 17.

According to the present invention, in such a reinforced concrete box, thin steel plates 14 are attached to both front and rear end faces which are the faces of the openings 17 or front end faces. The shape of the steel plate 14 is substantially the same as the shape of the front and rear end faces of the concrete box 4.

Further, when the concrete box 4 is manufactured, the steel plate 14 can be easily provided by arranging it in a concrete form and mounting it by simultaneous molding during concrete pouring, but it can also be installed later. As shown in FIG. 2, the steel plate 14 has an anchor 15, which is integrated with the concrete box 4.

The overall outline of the open shield construction method using the concrete box 4 of the present invention is as shown in FIGS. 3 to 6, and detailed description thereof will be omitted. However, excavation by the open shield machine 1 and concrete By repeating the setting process of the box 4, the concrete boxes 4 are left in the ground in a row along with the forward movement of the open shield machine 1, and the back of the concrete box 4 is backfilled 5.

In this case, the concrete box 4 receives the reaction force when the propulsion jack 3 is extended for advancing the shield machine 1. However, even if a considerable load is applied to the front end of the concrete box 4, this portion is affected by the steel plate 14. Since it is protectively covered, the steel plate 14 increases the rigidity to form a high-strength portion,
There is no possibility of cracking by splitting. This is also the case when performing a curve construction, which means that the stroke of the propulsion jacks 3 arranged on the left and right inside the shield machine 1 is made different and the shield machine 1 is bent and moved forward. It is possible to prevent the occurrence of cracks, though the load is uneven.

The concrete box 4 to be hung inside the shield machine 1 is connected to the concrete box 4 previously installed in the shield machine 1 with steel rods or long bolts, but the concrete boxes 4 are connected to each other. When this is done, the steel plates 14 come into contact with each other, so that the peripheral edges of the steel plates 14 are joined together by welding 16 from the outside of the concrete box 4 to make a watertight seal.

The peripheral edges of the steel sheet 14 may be connected to each other only by the welding 16 at the outer peripheral side or the inner peripheral side, but if the peripheral edges of both the inside and the outside are connected by welding, a double watertight sealing of the inside and the outside is achieved. High sealability. Further, when only the inner peripheral ends of the steel plates 14 are joined together by the welding 16, the worker can perform the welding work from inside the concrete box 4, and the narrow shield machine 1 can relatively easily perform the work.

[0021]

As described above, according to the open shield construction method of the present invention, cracks can be prevented from being generated even if a load for pushing out by a propulsion jack is received, and a highly reliable underground structure can be constructed. Is.

Further, the water blocking between the concrete boxes can be easily and completely performed even with a large cross section.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a concrete box used in the method of the present invention.

FIG. 2 is a vertical sectional side view showing a connected state of a concrete box used in the method of the present invention.

FIG. 3 is a vertical sectional side view of a first step showing an outline of an open shield construction method.

FIG. 4 is a vertical sectional side view of a second step showing an outline of the open shield construction method.

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

FIG. 6 is a vertical sectional side view of a fourth step showing an outline of the open shield construction method.

[Explanation of symbols]

1 ... Open shield machine 1a ... Side wall plate 1b ... Bottom plate 2 ... Blade 2a ... Slide retention plate 3 ... Propulsion jack 4 ... Concrete box 4a ... Left side plate 4b ... Right side plate 4c ... Upper floor plate 4d ... Lower floor plate 5 ... Backfilling 6 ... Excavator 7 ... Push angle 8 ... Starting pit 9 ... Reaction wall 10 ... Strut 11 ... Ground improvement 12 ... Pavement 13 ... Reaching pit 14 ... Steel plate 15 ... Anchor 16 ... Welding 17 ... Opening

Claims (1)

[Claims] 1. A process of arranging propulsion jacks inside left and right side wall plates, excavating and discharging earth and sand from the front or top opening of an open shield machine having front, rear and top openings, 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 the top behind the propulsion jack that was contracted in the tail part of the shield machine. In the open shield method of sequentially burying concrete boxes in vertical columns, the concrete box is made of reinforced concrete and consists of a left side plate, a right side plate, an upper floor plate and a lower floor plate. Anchors are provided on both the front and rear end faces, which are the surfaces of the concrete box, or on the front end faces, which are steel plates made of thin plates having almost the same shape as the front and rear end faces of the concrete box. It is affixed so that it is integrated with the concrete box, and the adhering part of this steel plate receives the propulsion jack load. An open shield method characterized by welding the ends together and sealing them in a watertight manner.