JPS6346239B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an expansion shield excavation method for expanding the diameter of an existing tunnel.

(Prior art) The present applicant previously filed a patent application for this type of construction method in 1982-
No. 215322, installing guide rings along the circumferential direction at both ends of the area scheduled for expansion of the existing tunnel,
A part of the primary shield segment between the rings is peeled off, and the ground in the peeled off area is excavated to form a base cavity. engaging the engaging pieces provided on both sides and engaging the engaging pieces provided on both sides of the circumferential segment fixed to the rear of the excavator;
We have proposed a method in which the rear part of the circumferential segment is pressurized by a jack so that it can be expanded by moving forward along the guide ring of the excavator.

(Problems to be Solved by the Invention) However, in such an excavation method, not only is it difficult to arrange the guide ring, but also a large pressure force is applied to the shield excavator that simply engages the guide ring. Therefore, there were problems such as the pressure means becoming bulky.

(Means for Solving the Problems) The present invention aims to solve the above problems by installing partial guide rings in advance at both ends of the planned expansion area of an existing tunnel consisting of primary shield segments. and a partial movable ring that is inserted into the partial guide ring, and the movable ring in the circumferential direction is attached by connecting the partial guide ring and the partial movable ring. A guide ring in the circumferential direction into which the guide ring is inserted is formed, a part of the primary shield segment between the shield segments with the guide ring is peeled off, and the ground at the peeled part is enlarged and excavated to form a base cavity. residing within the base cavity and on the movable ring;
A shield excavator for outer peripheral excavation and a circumferential segment connected to the excavator are fixed together, and an internal gear formed on the inner surface of the movable ring is meshed with a drive gear to attach the shield excavator to the guide ring. The tunnel is excavated in the circumferential direction along the existing tunnel, and circumferential segments of the same shape are sequentially connected to the circumferential segment at the rear of the shield excavating machine that excavates, and the circumferential segments are fixed to a movable ring. The method is characterized in that the area to be expanded is expanded by sealing with continuous fixation.

(Example) The present invention will be described below based on the drawings. Reference numeral 1 indicates an existing tunnel, and the tunnel 1 is formed by assembling primary segments 2, and primary segments 2a, 2a at both ends of the planned expansion area of the tunnel 1. A partial guide ring and a partial movable ring fitted into the partial guide ring are provided in advance, and these partial guide rings and a partial movable ring are assembled by assembling the primary segments 2a, 2a. A guide ring 3 with a movable ring 4 in the circumferential direction is formed at both ends of the planned expansion area of the existing tunnel 1 by connecting a movable ring with a movable ring, and the movable ring 4 has internal teeth that mesh with a drive gear 10 to be described later. A ring 8 is formed. Note that the internal tooth ring 8 is shown in the figure and is formed to protrude from the inner periphery of the guide ring 3, so the guide ring 3 is divided into two parts in the circumferential direction, and a holding frame is provided to prevent the part from coming off. However, when the internal tooth ring 8 is formed to be located on the inner circumferential surface of the guide ring 3, the inner tooth ring 8 is attached to the inner circumference of the guide ring 3. It is sufficient to provide a notch through which the matching drive gear 10 faces, and the guide ring 3 is not divided into two parts in the circumferential direction, so that the ring 3 can be easily installed.

Then, in the tunnel 1, a part of the primary segment 2 between the guide ring-equipped shield segments 2a, 2a is linearly peeled off, and the known cavity 5 is formed by enlarging and excavating the ground at the peeled part.

Then, within the base cavity 5, the movable ring 4,
A shield tunneling machine 6 for outer circumferential excavation is attached to 4, and the tunneling machine 6 is formed with a rectangular frame body whose front surface is a blade surface, and a circumferential segment 7 is attached to the back surface of the shield tunneling machine 6.
One of the segments 7 is fixed, and the inner peripheral edge of the segment 7 is also fixed to the movable rings 4, 4. Further, the movable ring 4 is formed with an internal gear 8 on its inner periphery, and the gear 8 is meshed with a drive gear 10 provided on a drive motor 9 such as a hydraulic motor or an electric motor to drive the drive gear 10. The shield excavator 6 sequentially excavates in the circumferential direction of the existing tunnel 1 along the guide ring 3 by the rotation of the movable rings 4, 4 rotated at circumferential segment 7
An enlarged tunnel is formed which is sealed with

(Effects of the Invention) As described above, according to the present invention, the guide is provided with a guide ring 3 at both ends of the planned expansion area of the existing tunnel 1 consisting of the primary shield segment 2, and a movable ring 4 fitted into the ring 3. The shield segments 2a with rings 2a, 2a are installed, a part of the primary shield segments 2, 2... between the shield segments 2a, 2a with guide rings is peeled off, and the ground at the peeled part is enlarged and excavated to create a base cavity 5. forming a movable ring 4, existing within the base cavity 5;
A shield tunneling machine 6 for outer peripheral excavation and a circumferential segment 7 are fixed to the movable ring 4, and an internal gear 8 formed on the inner surface of the movable ring 4 is meshed with a drive gear 10 to guide the shield tunneling machine 6 sequentially. Since the tunnel was excavated along the ring 3 to the outer periphery of the existing tunnel 1, the guide ring in the planned expansion area was installed separately from the segment as in the previous application mentioned above, and the shield excavator was engaged with and attached to it. It not only makes it easier to install the guide ring compared to the conventional guide ring, but also allows for smoother sliding inside the guide ring of the shield tunneling machine.
Moreover, since the shield tunneling machine excavates by rotating the internal toothed gear 4, it is easy to excavate, and unlike the earlier application mentioned above, it does not require reinforcement of the base cavity because it does not have a pressurizing device in the base cavity. In addition, the base cavity can be widely used for soil removal work or for attaching the circumferential segments 7, which has the effect of greatly improving work efficiency.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the tunnel under construction, Figure 2 is an enlarged view of part A in Figure 1, and Figure 3 is a - of Figure 1.
FIG. 1... Existing tunnel, 2... Primary shield segment, 2a... Shield segment with guide ring, 3... Guide ring, 4... Movable ring,
5...Base cavity, 6...Shield excavator, 7...
Circumferential segment, 8... internal gear, 10... drive gear.

Claims (1)

[Claims] 1. Installing shield segments that are equipped with a partial guide ring and a partial movable ring that is inserted into the partial guide ring in advance at both ends of the planned expansion area of the existing tunnel consisting of the primary shield segment, The connection between these partial guide rings and the partial movable ring forms a circumferential guide ring into which the circumferential movable ring is inserted, and a part of the primary shield segment between the shield segments with the guide ring. A base cavity is formed by peeling off the ground in the peeled off area and expanding the excavation, and a shield excavator for outer circumferential excavation and a circle connected to the excavator are installed in the base cavity and attached to the movable ring. Shield excavation is carried out by fixing the circumferential segment to the movable ring and meshing the internal toothed ring formed on the inner surface of the movable ring with the drive gear to cause the shield excavation machine to excavate in the circumferential direction of the existing tunnel along the guide ring. Circumferential segments of the same shape are sequentially connected to the circumferential segment at the rear of the machine, and the circumferential segments are fixed to a movable ring, and the circumference is sealed with continuous fixation of the circumferential segments to expand the area to be expanded. An expansion shield excavation method characterized by expanding and creating land.