JPH047493A - Tunnel widening method and device - Google Patents

Abstract

PURPOSE:To make it possible to excavate a partially enlarge tunnel by providing a shield excavator equipped with a rotary blade on the front end thereof so that it is capable of moving in the radial direction of rotation and a divided and prepared widening excavator together as a unit in an underground space. CONSTITUTION:Approximately ring-shaped vertically bisected parts 7a of a widening excavator 7 are assembled on the peripheral surface of a drum of a shield excavator 5 in the shape of a ring in an underground space 3b. After that, a rotary blade of the shield excavator 5 is pushed outward to the end of the widening excavator 7 to move. Then, the widening excavator 7 is launched together with the shield excavator 5 into the ground, and the earth within the limits equivalent to the external diameter of the widening excavator 7 is excavated with the rotary blade 6. The excavated earth is removed from the inside of a tunnel via a screw conveyor. According to the constitution, a widening space is excavated, and enlarged segments 9 are assembled in succession to the rear end of the widening excavator 7.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is directed to a tunnel in which a tunnel having a cross-sectional area larger than the tunnel being excavated is partially excavated by utilizing a narrow underground space such as a shaft of a starting base. Regarding widening construction methods and equipment.

(Conventional technology) Conventionally, vertical shafts are excavated underground at multiple locations, and underground spaces such as a starting base and material loading base are built deep inside the shaft, and a shield excavator is launched from the starting base to create a tunnel. The tunnel shield method of excavating the tunnel is known.

In this construction method, it is possible to construct a tunnel with a cross-sectional area corresponding to the excavation diameter of the shield excavator, but it is not possible to construct a tunnel with a partially large cross-sectional area.

In railway and cable tunnels, a widening space with a larger cross-sectional area than the standard part is provided in the middle as a facility space for ventilation and drainage, or a space for connecting cables. It was necessary to perform the excavation by excavation or replacing it with a shield excavator with a larger excavation diameter.

(Problem to be solved by the invention) In order to construct a widening space in the tunnel by excavating the above-ground part, a relatively large space is required on the ground as well, and if that space is not available, a large shield excavator may be used. A large shaft will need to be built to accommodate the introduction, and a large shield excavator will be used to excavate only the section of the widening space, and then a standard excavator will be used to excavate again. However, replacing the shield excavator and the associated construction work is actually extremely difficult work, and has the disadvantage of increasing construction time and cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for easily excavating a tunnel having a widening space in the middle even if there is no excavation space above ground, and an apparatus used therefor.

(Means for Solving the Problems) In the present invention, a widening excavator having a cylindrical hollow part is divided and prepared in an underground space into which materials can be carried, and the widening excavator is provided with a rotary machine that can freely move in the direction of the rotation radius. Propelling a cylindrical shield excavator with a blade at the tip to meet the underground space, and when the shield excavator appears in the underground space, integrally attaching the widening excavator around it, One of the above objects is achieved by extending the rotary blade of the shield excavator in the radial direction and excavating an enlarged tunnel by the driving force applied to the widening excavator.

The shield excavator used for this purpose includes a rotary cutting blade for excavation that is configured to be movable in the radial direction of rotation.

(Function) Along the route of the tunnel, there will be multiple loading and unloading bases for materials.
A shaft is provided as a starting base for the shield excavator, and a shield excavator equipped with a rotary blade movable in the radial direction at the tip is installed at the starting base, and the standard cross-sectional area of the tunnel is excavated using the radius of the rotary blade. After making these settings, the shield excavator is launched toward the next shaft. A vertical shaft is provided at the starting position of the tunnel widening space, and a substantially annular widening excavator is prepared, for example, divided into two parts, an upper and a lower part, in the underground space formed by the shaft.

The shield excavator is propelled by a jack to form a borehole of standard cross-sectional area, in which segments are assembled one after another and a tunnel is built in the same manner as in the conventional case. When the shield excavator appears in the underground space where the widening excavator is prepared, the divided widening excavator is attached integrally around the cylindrical shield excavator. It will have a double structure in which an annular widening excavator is fitted. Then, the rotary blade at the tip of the shield excavator is moved in the direction of its rotation radius, and after preparing to excavate an area equivalent to the cross-sectional area of the widening excavator by rotating the rotary blade, the widening excavator is jacked. It provides propulsion from the silt excavator and moves it along the planned excavation route together with the silt excavator.

When the widening space is excavated by the cooperation of the widening excavator and the shield excavator, a large-diameter enlarged segment that is suitable for the widening space is assembled in the underground space at the rear end of the widening excavator, and then jacked. The propulsion force is transmitted to the widening shield excavator through the widening segment, and the widening segment is gradually advanced into the widening space to be excavated.

When the widening space of the planned length has been excavated, the rotation radius of the rotary blade of the shield excavator is returned to the original radius, that is, the standard excavation radius, the shield excavator and the widening excavator are uncoupled, and the shield excavator Propel the chisel and excavate a tunnel with a standard cross-sectional area again.

(Example) An example of the present invention will be explained based on the case where a tunnel (2) having a widened space (1) as shown in the first diagram is excavated.
The tunnel (2) to be excavated will have multiple underground spaces (3) consisting of vertical shafts into which equipment can be brought in, and each underground space (3) will be used as a base for transporting equipment and a starting base for shield excavators. be done. A shield excavator is launched to excavate a tunnel (2) with a standard cross section from one underground space (3a) to the next underground space (3b), and as in the conventional shield construction method, the tunnel is excavated as shown in the second diagram. The next underground space (3b) is reached while assembling the standard diameter segment (4) in the rear excavation part of the shield excavator (5).

A rotary blade (6) provided at the tip of the shield excavator (5)
) has a configuration that is movable in the radial direction of rotation, and when excavating the tunnel (2) of the standard cross section, it is carried out without moving the rotary blade (6) in the radial direction. The radius of rotation at this time is, for example, 2.5 m, and when the rotary blade (6) is moved in the radial direction, the radius of rotation becomes, for example, 3.5 m.

In the next underground space (3b), as shown in Figures 2 and 3, there is a generally annular widening excavator (7
) is prepared, and when the shield excavator (5) appears in the underground space (3b), it is integrally attached to the outer periphery of the shield excavator (5) as shown in the fourth figure. The widening excavator (7) is designed so that its outer diameter when assembled is equal to the widening space (1) planned for the tunnel (2). Then, the rotary blade (6) of the shield excavator (5) is moved so as to extend to the end of the widening excavator (7), and the bulkhead (22
) The jack (8) pushes the rear end of the widening excavator (7) toward the side of the underground space (3b) that was blocked by the shield excavator (5), and sends it out underground together with the shield excavator (5). The rotating blade (
6) excavates earth and sand in a range corresponding to the outer diameter of the widening excavator (7), and as with the conventional one, the shield excavator (5)
is removed from the tunnel by a screw conveyor installed inside the tunnel. When the widening space (1) is excavated in this way, an expanding segment (9) corresponding to the diameter of the widening space (1) is continuously assembled to the rear end of the widening excavator (7) in the underground space (3b), and the jack (8) ) to increase the driving force of the expansion segment (9
) to the widening excavator (7). As the excavation of the widened space (1) progresses, the assembled expanded segments (9) also enter the widened space (1) one after another, and the widened space (1) is secured.

Each of the divided parts (7a) of the widening excavator (7) has an inner wall (11) and an outer wall (12) each having an arcuate cross section, and an intermediate wall (13) between them, each having a rib extending radially in the radial direction. (14), with a plurality of axial spaces (15) therebetween, and the tip (15) of the outer wall (12).
12a) is made to protrude forward from the inner wall (11) and the intermediate wall (13) to become a cutting edge (16), as shown in FIG. Each divided part (7a) is connected to a shield excavator (
The widening excavator (7) is assembled in an annular shape on the outer periphery of the body of the widening excavator (7).A buffer segment (17) is integrally attached to the rear end of the widening excavator (7), and the shield excavator (5) ) to support the rod (19) of the propulsion jack (18). The joke (18)
is used to propel the shield excavator (5) when it finishes excavating the widening space (1) of the planned length and then continues to excavate a tunnel (2) with a standard cross section. Similar to the shield construction method, the shield excavator (5) is further propelled by the jack (18) with the standard diameter segment (4) assembled behind it until it reaches the next underground space.

In Figure 6, (20) is the reaction force receiver of the jack (8),
(21) is a sealing material.

As shown in FIG. 8, the rotary blade (6) of the shield excavator (5) is composed of, for example, six sets of blades (6a) provided radially in the direction of its rotation radius, three of which are
The set of blades (6a) was moved in the radial direction as shown and rotated at low speed to excavate the cross section of the widening space (1).

Although not shown, earth and sand carrying means such as a screw conveyor is installed inside the shield excavator (5).

(Effects of the Invention) As described above, according to the present invention, a shield excavator is provided in which a widening excavator is divided and prepared in an underground space, and a shield excavator is equipped with a rotary blade movable in the rotation radius direction at the tip. When it appears in the underground space, the expanding excavator is integrally attached around it, and the rotary blade is extended in the radial direction to excavate an enlarged tunnel by the propulsive force given to the widening excavator. Therefore, when excavating a tunnel using the shield method, the widening space can be excavated at the same time, and the widening space can be constructed without excavation work, which is advantageous when there is no open excavation space above ground. It is possible to economically excavate tunnels with widening spaces, and the rotary excavation blade installed at the tip of the shield excavator is configured to be movable in the direction of its rotation radius, making it easy to replace the shield excavator. It is possible to excavate a large cross-section without having to do anything, and the construction period can be shortened.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a tunnel having a widened space, Figs. 2 to 8 show embodiments of the present invention, and Figs. 2, 4, 6, and 7 show the construction method of the present invention. A cross-sectional view showing the process, FIG. 3 is a cross-sectional view taken along line m-■ in FIG. 2, and FIG.
The V-line sectional view and FIG. 8 are front views of the rotary blade of the shield excavator. (1)... Widening space (2)... Tunnel <8) (3a) (3b)... Underground space (5)...
Shield excavator (6)... Rotary blade (7)... Widening excavator (8)... Applicant for permission to apply for permission to Mitsui Construction Co., Ltd. Kin Kitamura - To three other doctors

Claims (1)

[Claims] 1. A widening excavator having a cylindrical hollow part is prepared separately in an underground space into which materials can be carried, and a rotary blade movable in the rotational radial direction is provided at the tip. A cylindrical shield excavator is propelled to meet the underground space, and when the shield excavator appears in the underground space, the widening excavator is integrally attached around the shield excavator. A tunnel widening method characterized by excavating an enlarged tunnel by extending a rotary blade in the radial direction and applying a driving force to a widening excavator. 2. A device used in a tunnel widening method, characterized in that a rotary excavation blade provided at the tip of a shield excavator is configured to be movable in the radial direction of rotation.