JPH01163399A - Method of shield excavation construction - Google Patents

Abstract

PURPOSE: To form an enlarged width part in a tunnel by carrying out enlarged excavation with the length and with the angle of a boom changed, and thereafter by filling the concrete in the enlarged with part, and by grinding a part of the concrete after the concrete is cured to a prescribed degree of hardness. CONSTITUTION: Enlarged excavation is carried out by changing the length and angle of a boom 10, having a cutter 11 for a natural ground excavator 1 in a zone to be enlarged of a tunnel. Then, a shield 3 is advanced by jacks 4 which obtain reaction force from segments 6. Concrete is filled in an enlarged width space defined in rear of the shield 3. After the concrete is hardened to a prescribed degree of hardness, a part of the concrete is cut so as to form an enlarged cutout.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a shield excavation method for tunnels, and in particular, a method for enlarging a tunnel by enlarging and excavating the ground in an area to be expanded using a ground excavator. Regarding shield excavation method.

<Prior Art> For example, in a tunnel for laying underground cables, an enlarged tunnel section is provided so that various operations such as cable connection can be performed within the tunnel. In addition, such tunnel expansion work involves changing the dimensions of the cutter head while excavating a normal-diameter tunnel using the shield method, or using a vertical shaft that is separately excavated from the ground after excavating a normal-diameter tunnel. , ground improvement methods such as freezing construction methods are being carried out, and expansion and excavation of the planned expansion area is being carried out.

<Problems to be Solved by the Invention> However, in the conventional shield excavation method, when changing the dimensions of the cutter head.

Since it is necessary to temporarily suspend excavation work, work efficiency decreases, and the construction period and construction cost increase.In addition, the method of using a vertical shaft not only increases the construction period and construction cost as described above, but also works in urban areas. Implementation is often difficult due to various constraints such as regional conditions and underground conditions such as the presence of underground obstacles, and it is necessary to backfill the shaft after construction, leading to an increase in layer construction costs. There were problems such as:

This invention was made by focusing on such conventional problems, and uses a rock excavator to efficiently expand and excavate a tunnel while lining with cast-in-place concrete.
Furthermore, the objective is to obtain a shield excavation method that can be implemented at low construction costs.

<Means for Solving the Problems> The shield excavation method according to the present invention is such that in the area where the tunnel is to be expanded, the expansion excavation is carried out by changing the length and angle of the boom having the cutter of the earth excavator, and then The shield is moved forward by the jack, which receives a reaction force from the segment, and the widened part created on the back side of the shield is filled with concrete, and after the concrete hardens to a specified level, a part of the concrete is scraped off to create an enlarged notch. It is designed to form a section.

<Function> The earth excavator according to the present invention can enlarge the tunnel to a predetermined size by expanding the working area by extending the boom, changing the angle, etc., and by moving the shield forward by jacking after the enlarged excavation. A space can be formed between the shield and the ground, which is the widened part due to the enlarged excavation. Therefore, by filling this space with concrete using the above-mentioned shield as an inner formwork, and enlarging the excavation again using a earth excavator after it hardens, a concrete-lined tunnel can be continuously formed, and this concrete-lined tunnel can be continuously formed. To easily form an enlarged tunnel part by scraping off the part.

<Embodiment of the Invention> An embodiment of the invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a rock excavator used for carrying out the method of the present invention. In the figure, 1 is a rock excavator, and 2
It has a shield 3 that is propelled into the inner tunnel. A jack 4 is attached to the inside of the shield 3, and a cutting edge 5 is provided at the tip of the shield 3. Further, the rear end (piston rod end) of this jack 4 is abutted against the end surface of segments 6 that are successively laid as the tunnel is excavated. 7 is a partition wall that separates the inside of the tunnel,
A plurality of jacks 4 are attached to this partition wall 7. Reference numeral 8 denotes a power unit of the excavation machine, which is attached to the bulkhead 7 and connected to an arm 9 on the face side. A boom 10 is connected to the arm 9 and operates by receiving the power from the power section 8, and is configured to be rotatable and extendable. 11 is a cutter attached to the tip of the boom 10;
2 is a mud feeding pipe that supplies muddy water to the face 13 side, that is, between the face 13 and the partition wall 7; 14 is a mud drainage pipe that sucks muddy water mixed with excavated earth and sand and sends it to the ground, etc.; It can be moved in and out and rotated.

Next, in order to excavate a tunnel using the rock excavator 1 having such a configuration, the rock excavator 1 is placed in the tunnel by an arbitrary method, and the mud feeding pipe 12 is connected to the face 13 side of the partition wall 7. The power unit 8 is operated while muddy water is injected through the pump. Therefore, the power of the power unit 8 is transmitted to the boom 1 via the arm 9.
0, the cutter 11 is rotated within a predetermined area by the expansion/contraction and angle change of the boom 10 to excavate the earth. The propulsion force at this time is obtained from the jack 4, which expands while receiving pressure from the segment 6.

Then, by sequentially adding the segments 6 in this propulsion, a tunnel covered with the segments 6 is obtained. Further, muddy water generated by excavating the face 13 is lifted to the ground through the mud drainage pipe 14.

In this propulsion process, when the earth excavator 1 reaches the area where the tunnel is planned to be expanded, the boom 9 is greatly extended to expand its operating area. Thereby, as shown in FIG. 2, the cutter 11 excavates the earth 2 in the radially outward direction while protruding outward beyond the diameter of the shield 3. At this time, the boom 9 may be displaced while repeatedly extending and contracting as necessary. In this way, enlarged excavation of the tunnel into the ground 2 is performed. Next, when this enlarged excavation has progressed to a predetermined amount, as shown in FIG. Stretch it. Then, the shield 3 moves forward so that the cutting edge 5 bites into the face 13 of the earth 2.

Then, a space is created between the shield 3 and the enlarged excavation portion, that is, on the outside of the shield 3. Therefore, concrete 15 is injected into this space from the hose 16 using a concrete injection device (not shown), and the shield 3
Completely fill with concrete 15 using the inner formwork. It is desirable to provide about six injection ports for pouring the concrete 15 inside the shield 3 so that the concrete 15 can be poured uniformly and quickly throughout the space. Note that at this time, segment 6 is also added.

After pouring the concrete 15, when the concrete becomes self-supporting, that is, when it reaches a hardness that will not easily collapse, the power section 8 is operated again, and the Boom 1 as shown in Figure 4
0 can be extended to continue extended excavation. When the expansion excavation of the desired area to be expanded is completed by such operations, a part of the tunnel becomes a form in which the outside of a plurality of continuous segments 6 is filled with concrete 15, as shown in FIG.

Next, in a tunnel consisting of such segments 6, after the earth excavator 1 is moved from this part, the segment 6 of this part is first removed, and then a scraping machine such as a big hammer is used to remove the hardened concrete 15. If this is removed, an enlarged tunnel consisting of notches 17 will be obtained, as shown in FIG.

As described above, according to the method of the present invention, expansion excavation can be carried out efficiently by simply using the earth excavator 1, without using a special expansion shield machine or improving the ground in the expansion area. This will enable shield propulsion.

<Effects of the Invention> As described above, according to the present invention, in the area where excavation is planned to be expanded, the length and angle of the boom of the earth excavator are changed and the cutter is used to perform expanded excavation. During normal tunnel excavation,
In addition to continuing to perform expanded excavation using the same rock excavator, the space outside the shield created when the shield is advanced after the expanded excavation described above is filled with concrete, and after the concrete hardens to a specified level. Since the enlarged notch is formed by scraping off a part of the tunnel, the concrete structure of the tunnel enlarged part can be formed in parallel with the excavation work. In addition, after the expansion excavation is completed, it is possible to easily and economically obtain a partially expanded tunnel by simply removing the segment in this area and scraping off the concrete that has not yet completely hardened to the required thickness. Effects can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a rock excavator used to implement the shield excavation method of the present invention, FIGS. 2 to 4 are explanatory diagrams for explaining the shield excavation method of the present invention in detail, and FIG.
The figure is a sectional view showing the concrete filling structure in the enlarged excavation part, and FIG. 6 is a sectional view showing the enlarged part of the tunnel made by cutting concrete. 1. Earth excavator, 3. Shield, 4. Jackpot,
6...Segment, 10...Boom, 11...Cutter,
12...Sludge feeding pipe, 13...Face, 15...Concrete, 14...Sludge removal pipe. 16...Hose. Patent applicant: Ichima Co., Ltd. Patent attorney: Sakai
cum saka isodo cum
Shigeru Saka l4-Boyin Y Figure 2 Figure 4 Figure 3

Claims (1)

[Claims] 1) In a shield excavation method in which a tunnel face is excavated by a earth excavator and a reaction force is obtained by a segment installed on the inner peripheral surface of the excavation and a shield is propelled by a jack, in an area scheduled for expansion, After expanding the excavation by changing the length and angle of the boom with the cutter or by sliding the excavator and advancing the shield, fill the widened part on the back side of the excavated shield with concrete. A shield excavation method characterized by forming an enlarged notch by scraping off after a certain amount of hardening. 2) In the shield excavation method, a face is excavated by a rock excavator and a reaction force is obtained by segments installed on the inner circumferential surface of the excavation, and the shield is propelled by a jack.In the area planned for expansion, muddy water is supplied to the face side. After expanding the excavation by changing the length and angle of the boom with the cutter and moving the shield forward, the widened part on the back side of the excavated shield is filled with concrete, and after it has hardened to a specified level, it is scraped off to form the enlarged notch. A shield excavation method characterized by the formation of