JPH031479B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a shield tunnel partial expansion method for partially expanding the cross section of a shield tunnel.

(Prior Art) Recently, there have been many cases in which ultra-high voltage power cables are wired inside shield tunnels. In this case, since the power cable connection requires a larger cross section than the other cable cross sections, conventionally all connections have been made within the shaft. However, in recent years, shield tunnels have tended to become deeper and deeper, and therefore installing a vertical shaft requires a large amount of construction cost, and even in the case of a shield tunnel with a small depth, ground conditions, such as traffic The current situation is that construction is becoming extremely difficult in many cases due to factors such as road size and road width.

(Problem to be solved by the invention) Therefore, various construction methods have been proposed for partially expanding the shield tunnel, but these construction methods require special machinery and equipment in sections where the construction length is extremely short. The construction method is complicated, the construction costs are high, and the construction period is long, so the reality is that it is rarely used.

(Object of the invention) The present invention has been devised in view of the above points, and
It is an object of the present invention to provide a method for partially expanding a shield tunnel, which allows the cross section of a shield tunnel to be easily expanded only by working inside the shield tunnel, and which can be constructed at low cost.

(Structure of the Invention) The present invention uses a segment having an opening/closing window and an earth anchor through hole in the upper segment of a partially enlarged section in a shield tunnel, and when constructing the expanded part, an earth anchor is driven through the through hole. At the same time, the opening/closing window is opened to scrape off the upper ground, the segment is raised using the earth anchor as a guide, and an enlarged segment is attached to the subsequent side wall to partially enlarge the shield tunnel. It is possible to partially enlarge the cross section of a shield tunnel by simply working inside the shield tunnel without using any special machinery or equipment.

(Effects of the Invention) According to the present invention, the construction is extremely easy and the upper segment can be reused as it is for the enlarged part, so it is economical and can be constructed at low cost. Since it has a circular cross section, it has a large resistance to external forces. Further, since the segments of the enlarged section can be assembled in the same manner as other parts, it is possible to produce effects such as not adversely affecting the excavation speed during shield excavation.

Example Fig. 1 shows a segment of a partially enlarged section of a shield tunnel, and Fig. 2 shows a side view thereof. Segment 1 of the same section is K segment 2, B segment
It consists of a segment 3 and an A segment 4, and is assembled using a horizontal piece-to-piece joint 5 and an inter-ring joint 6 in the same manner as segments commonly used during shield excavation.

Each of the K, B, and A segments is composed of a skin pluto 7, a segment main girder 8, and a segment joint plate 9, and the B segment 3 and A segment 4, which constitute the upper segment, have opening/closing windows as described below. 10 is provided, and the B segment 3 is also provided with a through hole 11 for an earth anchor, which will be described later.

FIG. 3 shows a reinforcement 12 used to prevent deformation of the upper segment of the enlarged section when the upper segment is raised, and FIG. The main girder 13 has the same radius of curvature as the inner surface of the upper segment.
It is composed of a connecting material 14 connecting between the two, an earth anchor through hole 15 provided in the main girder 13, and a washer 16.

It is preferable to use steel as the reinforcing material.
In this example, a square pipe is used.

5 and 6 show expanded segments, and the expanded segment 17 shown in the left half of FIGS. 5a and 6 is composed of a skin plate 18, a segment main girder 19, and a segment joint plate 20, The enlarged segment 17a shown in the right half of FIG. 5b and FIG. 6 is a segment with a small height that is easy to collapse and is used while being piled up on the ground. 20 and a horizontal inter-piece joint 21.

FIG. 7 is a plan view of a segment having the opening/closing window 10, and FIG. 8 is a sectional view taken along the line A--A in FIG.

Segment main girder 8 has inter-ring joint bolt hole 2
2, an inter-piece joint bolt hole 23 is provided in the segment joint plate 9, and a window 24 is provided approximately in the center of the skin plate 7 so as to be openable and closable via a bolt 25 and a nut 26.

Next, the procedure for partially enlarging the shield tunnel will be explained with reference to FIGS. 9 to 13.

In Fig. 9, a is an axial sectional view of the shield tunnel before expansion, b is the A-A line, and c is the B-
A sectional view taken along the line B. 31 is the ground, 32 is the shield tunnel general part, 33 is the shield tunnel enlarged part, 34 is the upper segment of the enlarged part, 35 is the lower segment of the enlarged part, and the upper segment 34 and the lower segment 35 are shown in FIGS. It is composed of each segment already explained in FIG.

First, a in Figure 10 and its A-A line and B-B
As shown in b and c, which are cross-sectional views taken along the line, two earth anchors 38 are inserted upward in parallel in each upper segment through the earth anchor through holes 11 provided in the upper segment 34 throughout the enlarged section. At the same time, the chemical solution injection zone 37
A chemical solution is injected into the upper segment 34, and a reinforcing member 12 is attached to the inside of the upper segment 34. Driving the earth anchor 38 and injecting the chemical solution may be performed using a boring machine installed in the mine.
The chemical solution can be injected through the grout hole installed in the segment, and the reinforcing material 12 can be installed by passing the earth anchor 38 through the through hole 15 and tightening the nut 39 as shown in FIGS. 14 and 15. It can be fixed by

Next, the nut 26 is removed, the window 24 of the upper segment 34 is opened, and the upper segment 34 is raised together with the reinforcing member 12 by rotating the nut 39 while scraping off the upper ground 31.

FIG. 11a shows an axial cross-sectional view of the tunnel after some of the upper segments 34 have been raised to a predetermined position as described above, and then the enlarged segments 17 have been attached. Further, b and c show cross-sectional views taken along the line A-A and line B-B in a.

This work is carried out while ensuring safety by not constructing the enlarged sections at the same time, but by constructing them at appropriate intervals, for example every other ring as in this example.

For excavation, input or a small breaker may be used. Furthermore, in the case of a rock that is prone to collapse, for safety reasons, the process can be carried out while stacking enlarged segments 17a with small heights.

FIG. 12a shows that the upper segment 34 of the entire enlarged section is raised to a predetermined position, and the enlarged segment 1
Fig. 7 is a sectional view in the axial direction of the tunnel showing a state in which the installation of Fig. 7 has been completed, and b and c are sectional views taken along line A-A and line B-B.

After the upper segment 34 has been raised to a predetermined position in this manner, the tunnel axial cross-sectional view shown in FIG.
As shown in the figure, the primary lining of the shield tunnel expansion section is completed by cutting the earth anchor 38 near the inner peripheral surface of the upper segment 34 and removing the reinforcing material 12, and then the secondary lining is completed by pouring concrete. The construction of the enlarged section will be completed by carrying out this work.

According to the shield tunnel partial expansion construction method described above, the following numerous effects can be obtained.

(1) It is economical because the segments used during shield excavation can be reused as they are for expansion.

(2) Since the enlarged section has a vertical oval cross section, it has a large resistance to external forces, making construction of the enlarged section economical.

(3) During shield excavation, the enlarged segment segments can be assembled in the same way as normal segments, so there is no effect on the shield excavation speed.

(4) Construction is extremely easy as the upper segment is raised using the earth anchor as a guide.

(5) Construction costs are low because no special machinery or equipment is required.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the segment, FIG. 2 is a side view of FIG. 1, FIG. 3 is a sectional view of the reinforcing material, and FIG.
The figure is a side view of FIG. 3, and FIGS. 5a and 5b are cross-sectional views of the enlarged segment, respectively. FIG. 6, the left half of the enlarged segment shown in FIG. 5a, and the right half of FIG. A side view of the enlarged segment shown, FIG.
A plan view of a segment with an opening window, FIG.
The sectional view taken along the line A-A in Fig. 7, and Figs. 9 to 13 are explanatory views of the construction procedure for the enlarged section, where a is an axial sectional view of the shield tunnel, and b is the A-A sectional view of the shield tunnel.
Line A and c are views showing cross sections taken along line B-B, No. 14
The figure is an enlarged view of part C in Fig. 11, and Fig. 15 is an enlarged view of section C in Fig. 11.
FIG. 1...Segment, 10...Opening/closing window, 11...
Earth anchor through hole, 12... Reinforcement material, 15...
... Earth anchor through hole, 17, 17a ... Expanded segment, 31 ... Earth, 32 ... Shield tunnel general section, 33 ... Shield tunnel enlarged section, 34 ... Upper segment, 37 ... Chemical injection zone, 38 ...Earth Anchor, 39...Natsuto.

Claims (1)

[Scope of Claims] 1. A segment having an opening/closing window and an earth anchor through hole is used in the upper segment of the partially enlarged section in the shield tunnel, and when constructing the enlarged part, the earth anchor is driven through the through hole and the The shield tunnel is partially expanded by opening an operable window to scrape off the upper ground, raising the upper segment using the earth anchor as a guide, and attaching an enlarged segment to the subsequent side wall. Shield tunnel partial expansion method. 2. The shield tunnel partial expansion construction method according to claim 1, characterized in that a reinforcing member is attached to the inside of the upper segment via a nut. 3. The shield tunnel partial expansion construction method according to claim 1, characterized in that as the upper segment rises, a plurality of enlarged segments with smaller heights are stacked and attached. 4. Claim 1, characterized in that the construction of the enlarged section is carried out at appropriate intervals within the enlarged section.
The shield tunnel partial expansion method described in section 2.