JP2628084B2 - Segment assembly method in shield method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for assembling a segment used as a tunnel lining material in a shield method.

"Prior art" Generally, for example, a shield construction method is known as an example of a tunnel construction method. This construction method follows the progress of excavation and protects the underground work space from earth pressure by pushing a shield excavator entirely covered with a cylindrical skin plate into the mine formed by the excavation, Also, in the shield excavator, the arc segments are assembled in an annular shape and connected in the axial direction, and a reaction force is taken from the annularly assembled segment, and the shield excavator is sequentially sent forward to thereby continuously connect the pit. It is to be constructed.

By the way, in assembling the above segments into a ring, the last segment S ₀ (so-called key segment)
The problem here is how to fit in. Conventionally, for example, a method of fitting from the inside as shown in FIG. 3 or a method of fitting in a manner shifted in the axial direction as shown in FIG. Was taken.

[Problem to be Solved by the Invention] However, in the above-described conventional segment assembling method, the key segment S ₀ and the segments on both sides thereof must each be formed in a unique shape different from other segments (FIG. 3). In FIG. 4, key segments in which the tapered surfaces T on both sides are inversely tapered must be used, and in FIG. 4, wedge-shaped key segments must be used in plan view.) ,
There is a disadvantage that three types of segments must be prepared.

Also, the segment receives earth pressure and water pressure from the ground,
At this time, key segment S ₀ shown in FIG. 3 is will receive a force away from both sides of the segment by the soil pressure and the like, eventually, the water-blocking secured on both sides junction becomes difficult.

Shall Further, any methods shown in FIGS. 3 and 4, when fixing the key segment S ₀ on both sides of the segment S, if the key segments S ₀ to the fixed ends supported while maintaining the exact position There is also a disadvantage that the workability is poor.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method of assembling segments in a shield construction method that can be performed with one common type of segment, and that is excellent in waterproofness and workability. .

Means for Solving the Problems In order to achieve the object according to the present invention, while forming a drilling hole by a shield excavator, a plurality of segments are annularly assembled in the shield excavator and the segments are connected to the drilling hole. In the shield construction method of constructing an underground structure while connecting in the axial direction, when assembling a segment in the shield excavator in an annular shape, the segment is formed between the original set position of the segment and the outer skin plate. Utilizing the clearance, the last segment to be fitted is placed outside the original setting position, and the other segments are set in an arc shape, and then the last segment to be set is placed from the outside. It is characterized by being fitted and assembled into a ring.

"Action" In this method, the last segment to be set in forming the ring is pushed in from the outside, instead of moving it inward or axially, so that it is the same as the other segment. Shaped shapes are available.

Also, when the segment receives earth pressure and water pressure from the ground,
The pressing component such as the earth pressure acts in a direction in which the ends of the respective segments are brought into tight contact with each other, so that good waterproofness can be secured.

Furthermore, when the last segment to be set is fitted into the existing segment linked on the arc, the segment itself is positioned and supported by the segments on both sides. The segments do not need to be specially supported while they are fixed to the segments on both sides.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory view in the process of assembling a segment by the method of the present invention, and FIG. 2 is a longitudinal sectional view of the same.

Before describing the method of the present invention, a shield excavator used in carrying out the method will be briefly described.

In FIG. 2, reference numeral 1 denotes a shield excavator. The shield excavator 1 is entirely covered with a tubular steel skin plate 2 as is well known, and a cutter 3 provided on a front surface thereof.
A hood portion 4 for excavation at the rear, a tail portion 5 for lining at the rear portion, and a ring gutter portion 6 for supporting and reinforcing the entire structure of the shield excavator at the center thereof.
Consisting of parts.

A hydraulic jack 7 for propelling the shield is provided in the ring gutter 6 at the center, and an erector 8 is provided in the tail 5. The erector 8 has a function of assembling the segment S, a grip device for grasping the segment S, and three axial directions (elevating, descending,
It is equipped with an adjustment device that adjusts to (sliding, turning).

Although the skin plate 2 has a cylindrical shape, part extending portion 2a formed by projecting outward is formed (the skin plate sign L ₂ in the second figure that has been used so far that shows the line of the upper end, L ₁ denotes a line of the upper end portion of the skin plate used in the for the implementation of this invention).

The place where the overhang portion 2a is provided may be in any direction in the circumferential direction. However, considering workability, it is preferable to provide the overhang portion 2a at the upper end as shown in FIGS. However, its length l ₁
Needs to be set at least larger than the segment length l ₂ . Actually, when connecting the segments in the axial direction, the segments are arranged so as to be shifted in the circumferential direction so that the joints Z in the circumferential direction do not continue as shown in FIG. Set a little wider in consideration of. Further, the overhang portion 2a may be provided so that the axial direction extends from the front end to the rear end of the skin plate 2 as shown in FIG.

Note that the shield excavator 1 is provided with a special excavation means so that a ground portion corresponding to the overhang portion 2a can be excavated.

Next, the operation of the shield excavator 1 will be described to clarify the method of the present invention.

In the shield excavator 1, while rotating the cutter 3 of the hood 4, the hydraulic jack 7 is driven to take a reaction force from the existing segment S, and excavates the ground while sending the excavator 1 itself forward. .

While excavating in this manner, the segments S are sequentially gripped by the erector 8 in the rear tail portion 5, and the segments S are assembled in an annular shape. At this time, in order to assemble in a ring shape, the segment S ₀ to be fitted last is formed by utilizing the clearance formed between the original set position of the segment and the skin plate 2 on the outside thereof, specifically,
By positioning the inner surface of the projecting portion 2a, allowed to positioned outward than the original set position, after setting the other segment S in an arc, and sets the segment S ₀ of said last.

As described above, since the segment S ₀ to be fitted last is set by pushing in from the outside, not from the inside or the axial direction, the last segment S ₀ is replaced by another segment S _0.
The same shape can be used. As a result, only one type of segment is required in principle, and the segment management is much easier than in the case of using the conventional method.

Further, when the annularly set segment S receives earth pressure and water pressure from the ground, it receives a force such that its annular diameter becomes small. As a result, as shown in FIG. A force component F acting in a direction of bringing the ends of S ₀ into close contact with each other acts, so that good water stopping properties can be secured.

Further, when the segment S ₀ to be set last is fitted from the outside into the existing segment S connected on the circular arc, the segment S ₀ itself is positioned and supported by the segments S on both sides, and the segment S _{0 is set.} between fixed to the opposite sides of the segment by means of bolts or the like, there is no need to support the same segment S _0, to improved workability.

"Effects of the Invention" As described above, according to the present invention, construction can be performed with one kind of common segment in principle, and segment management becomes easy. In addition, when the earth pressure and water pressure of the ground work, it works in the direction to press the ends of each segment tightly, so that good water stoppage is obtained, and the last segment to be set is installed on both sides. When fixing to a segment, there is no need to support the segment,
It has effects such as improvement of workability.

[Brief description of the drawings]

FIG. 1 is a sectional view in the middle of construction for assembling a segment by the method of the present invention, FIG. 2 is a longitudinal sectional view of the same, and FIGS. 3 and 4 are views for explaining a conventional segment assembling method. 1 ...... shield excavator, 2 ...... skin plate, 2a ...... projecting portion, 5 ...... tail portion, 8 ...... Elekta, S ...... segment, the segment is set to S ₀ ...... last.

Claims (1)

(57) [Claims] 1. An underground structure is constructed while assembling a plurality of segments into a ring in the shield excavator while forming the excavation hole by the shield excavator and connecting the segments in the axial direction of the excavation hole. In the shield method, when assembling the segments in a ring in the shield excavator, utilizing the clearance formed between the original set position of the segments and the skin plate on the outside thereof, the segments to be fitted at the end, A segment in a shield method, wherein the segment is set outside the original setting position, the other segments are set in an arc shape, and then the last segment to be set is fitted from outside to form a ring. Assembly method.