JP3072575B2 - Method of expanding segment ring and applying axial force - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for extending a segment ring and increasing an axial force for suppressing bending deformation or increasing bending strength of a segment ring in shield work.

[0002]

2. Description of the Related Art Conventionally, a lining segment in a shield method is generally installed at a predetermined position (circular) and then fastened by bolts between the segments.

[0003] In order to assemble the segments, some gaps are required between the segments, and these gaps remain as they are even after bolt fastening.

[0004]

In the above-mentioned conventional shield lining, there is some looseness between the segments due to the voids remaining between the segments, and the watertightness due to a decrease in bending strength, an increase in bending deformation, an opening, and the like. Adverse effects such as a decrease in

[0005] When the bending stiffness of the shield lining joint is small as described above, due to the difference in bending stiffness, when the secondary lining is applied in the future, the joint will resist the (additional) load simultaneously with the secondary lining. It cannot work.

[0006] For this reason, the primary lining cannot effectively act on a load gradually increasing with time as in the case of soft ground.

Further, after the lining segment is assembled in an annular shape, the lining segment comes into contact with an external load in a form of being pushed out of the shield. However, the outer periphery of the lining segment is eventually filled with the backfill injection material, and the ground reaction is caused. Combined with the mechanical deformation suppressing action, the resistance to an external load that attempts to deform from a circular shape to a crushed shape is obtained.

However, immediately after the shield has advanced, these backfill injections do not exist and the lining segment alone must resist an immediate load such as water pressure.

For this reason, in a deep tunnel or the like,
This point can be the most dangerous.

The deformation of the lining segment from a perfect circle also means that openings are formed on the outer surface, and the seal (water seal) between the shield and the segment may be in danger.

In general, a bolted joint structure has a lower strength than a seamless structure, and cannot effectively cope with such a situation.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, according to the present invention, at least one set of segments 3, 3 adjacent in the ring direction is provided with a tip in the vicinity of the joint surface of one segment 3. Is provided with a guide hole 6 opening in the joint surface, and a pressure member 5 having a convex arc-shaped end is inserted into the guide hole 6 so as to be able to advance and retreat in the ring direction.
A face cam 8 having a peripheral surface whose distance from the center of rotation changes behind the surface of the pressure body 5 is installed rotatably with the peripheral surface having a small distance from the center of rotation close to the rear end surface of the pressing body 5. 8, the end of the rotation operating shaft 9 protrudes toward the inner surface of the segment 3, and the face cam 8 is rotated via the rotation operating shaft 9 so that the pressing body 5 is moved by the peripheral surface whose distance from the rotation center is large. By pressing, the pressing body 5 is extruded, and the joining surface of the other segment 3 is pressed at the tip thereof to expand the segment ring and to apply an axial force. In this state, the face cam 8 is locked by the locking device 13. The present invention proposes a method for expanding a segment ring and applying an axial force so as to lock and prevent rotation in the reverse direction.

[0013]

When the key segment 4 is inserted into the predetermined position, the rotary operating shaft 9 of each axial force introducing device is rotated from the inner surface side of the segment 3 via the rotary operating end 10 thereof, whereby the face cam 8 is rotated. Is pressed so as to be pressed against the rear end face of the pressurizing member 5 on the arcuate peripheral surface having a large distance from the center of rotation to push the pressurizing member 5 forward. Is uniformly pressed to expand the space between the segments 3 and 3, and an axial force is introduced into the segment ring.

When a predetermined axial force is obtained, the rotation of the face cam 8 is stopped, and
To prevent reverse rotation of the face cam 8 in the loosening direction.

The bending moment due to an initial load such as its own weight acts so that an opening is formed inside the ring crown portion (top portion), and works outside the spring portion (horizontal horizontal portion).

However, since the bending at the crown portion is generally the maximum, the compressive force acting position is set slightly outside the center of the cross section at the crown portion to make the resistance effect more effective.

Whether the magnitude of the introduced axial force is limited to a level sufficient to ensure the close contact between the adjacent segments 3 or 3 or a level capable of actively resisting the bending load is selected depending on the situation. It shall be.

In order to resist the bending load, the resultant force of the introduction axial force and the bending moment is made to fall within the middle third of the cross section.

The space between the adjacent segments 3, 3 formed by the expansion is filled with a quick-setting hardening material such as a rapidly hardening cement kneading material and fixed.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a segment 3 is assembled in a ring shape inside a tail plate 2 of a shield machine 1. At this time, a key segment 4 of a ring crown is inserted last and assembled.

After the assembly, a compressive force (axial force) in the ring direction is applied to one of the joining surfaces on both sides of the key segment 4 in a normal shield work as shown in FIG.

However, if it is necessary to introduce an axial force at the joint surface of each segment adjacent in the ring direction in a muddy water shield or the like, after releasing the jack from the segment to be introduced, the joint force is simultaneously applied to each joint surface. Introduce.

FIGS. 3 and 4 show an apparatus for introducing such an axial force. As shown in FIG. 4, this axial force introducing apparatus is connected to the vicinity of one of the joining surfaces of the adjacent segments 3 and 3. A plurality of sets are buried in parallel and installed, and an axial force is introduced by pressing the joint surface of the other segment by a pressing body 5 provided in the device. As shown in FIG. 3, the segment ring is arranged to be eccentric to the outer periphery side by an appropriate amount from the axis line.

The pressurizing body 5 is a prism-shaped metal block having a convex arc-shaped tip as shown in FIGS. 5 and 6, and a tip provided near the joint surface of one of the segments 3 is connected to this joint surface. It is inserted into the guide hole 6 that opens so as to be able to advance and retreat in the ring direction.

A pressing portion protection case 7 is embedded at the rear end side of the guide hole 6, and a face cam 8 in which a part of a peripheral surface of a metal cylinder is cut into a half-moon shape in the pressing portion protection case 7.
The cut flat surface 8 ′ is installed rotatably in the vicinity of the rear end of the pressurizing body 5 and in a state where the lateral movement is restrained. It may be fixedly attached to the center of rotation, or may be one in which the rotation operating shaft 9 is removably connected to the connection portion of the face cam 8 at the center of rotation. The rotation operation end 10 having a shape or the like protrudes toward the inner peripheral surface side of the segment 3 to perform the rotation operation.

On the other hand, on the joining surface of the other segment 3,
A metal pressure receiving plate 11 is fixed at a position corresponding to the front end of the pressurizing body 5 by embedding an anchor 12 projecting from the rear end thereof in concrete.

The pressing portion protection case 7 includes a face cam 8
Face cam 8 at a position facing one side end of flat surface 8 '
A locking device 13 for preventing reverse rotation of the motor is provided.

As the locking device 13, for example, as shown in FIG. 7, a slope 14 inclined at a required angle with respect to the vertical surface of the flat surface 8 'of the face cam 8 is provided. A locking block 15 that slides in contact with the surface is arranged opposite to one side end of the flat surface 8 ′ of the face cam 8. For example, a mechanism equipped with a pushing spring 16 for elastically pressing the body is used.

In short, the locking device 13 is the face cam 8
Is rotated from a position where the rear end face of the pressurizing body is close to the flat surface 8 ′ whose distance from the center of rotation is small, and is pressed against the rear end face of the pressurizing body 5 on the circular arc surface whose distance from the rotation center is large. Then, following the rotation, the face cam 8 or a part of the rotation operation shaft 9 is locked at the rotation stop position, and the face cam 8 or the rotation operation shaft 9 is reversely rotated (return in a direction to loosen the pressure contact of the rear end face of the pressing body 5). Any mechanism may be used as long as it prevents rotation.

The face cam 8 is not limited to the illustrated embodiment, but may be any as long as it has a peripheral surface whose distance from the center of rotation changes.

The pressing body 5 is fixed to the periphery of the guide hole 6 using a small diameter pin 17 in order to keep the pressure body 5 pulled into the guide hole 6 until the assembly of the segment 3. The pin 17 is cut when the pressing body 5 is pushed out.

When the axial force is introduced into the segment ring by using the axial force introducing device having the above-described configuration, when the key segment 4 is inserted into a predetermined position, each axial force introducing device is inserted from the inner side of the segment 3. The rotary operating shaft 9 is connected to its rotary operating end 1
0, thereby causing the face cam 8 to move the face cam 8 on the arc peripheral surface at a large distance from the center of rotation.
The pressing body 5 is rotated so as to be in pressure contact with the rear end face, and the pressing body 5 is pushed forward, and the joint surface of the adjacent segment 3 is uniformly pressed by the convex arc-shaped tip of the pressing body 5 to expand the segment 3. At the same time, an axial force is introduced into the segment ring.

At this time, the axis of the pressure body 5 and the face cam 8
The center of rotation of the face cam 8 is previously decentered by an appropriate amount (the extension of the axis of the pressing body 5 does not pass through the center of rotation of the face cam 8). And the torque for rotating the face cam 8 is reduced.

When the rotation of the face cam 8 is stopped when a predetermined axial force is obtained, the elastic force of the pushing spring 16 (which maintains a strong elastic force even when the spring 16 is extended) causes the face cam 8 to rotate. The locking block 15 slid along the slope 14 following the rotation locks one end of the flat surface 8 ′ of the face cam 8 to prevent the face cam 8 from rotating in the loosening direction.

The voids formed at the joint surfaces between the adjacent segments 3 and 3 are expanded and filled with a quick-setting hardening material such as a rapidly-hardened cement kneading material to be consolidated and integrated.

In the case of a muddy water shield or the like, when it is necessary to introduce a compressive force between the segments 3 and 3 in order to remove looseness between the segments 3 and 3, the pressurizing operation side receiving a reaction force at the time of pressurizing is required. The segment 3 is fixed by the operation of the propulsion jack, and the propulsion jack of the segment 3 on the side that expands and moves by pressurization is floated to introduce an axial force.

[0037]

As described above, according to the present invention, the following effects can be obtained.

1) After assembling the segments, by expanding at least one of the joints of the segments in the ring direction, the looseness between the segments can be eliminated, whereby the bending rigidity of the segment ring increases and the bending strength increases. Increases, and bending deformation decreases, thereby improving watertightness.

2) By generating an axial force in the segment ring, it is possible to resist a bending moment due to an initial load such as its own weight.

As a result, the bending-tensile resistance member disposed in the cross section only needs to resist only the additional load, and the strength is greatly increased.

3) By increasing the bending rigidity of the primary lining,
The primary and secondary linings can simultaneously withstand external loads.

If a shear force transmitting device is installed between the primary and secondary linings, the composite plate can resist bending.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing an outline of a shield method.

FIG. 2 is a vertical sectional front view showing an outline of a shield method.

FIG. 3 is a partial front view showing an axial force introduction state according to the present invention.

FIG. 4 is a partial plan view showing an axial force introduction state according to the present invention.

FIG. 5 is a vertical cross-sectional view of the axial force introducing device according to the present invention.

FIG. 6 is a longitudinal sectional side view of the axial force introducing device according to the present invention.

FIG. 7 is a vertical side view of the face cam locking device according to the present invention.

[Description of Signs] 1 Shield machine 2 Tail plate 3 Segment 4 Key segment 5 Pressing body 6 Guide hole 7 Pressing portion protection case 8 Face cam 8 'Flat surface 9 Rotating operating shaft 10 Rotating operation end 11 Pressure receiving plate 12 Anchor 13 Locking device 14 Slope 15 Locking block 16 Push-in spring 17 Fine pin

Claims (1)

(57) [Claims] 1. A guide hole having a distal end opened to a joint surface of at least one set of segments adjacent to each other in a ring direction near a joint surface of one of the segments. A pressure cam having a peripheral surface having a different distance from the center of rotation is attached to the rear of the pressure member with a peripheral surface having a smaller distance from the center of rotation. It is installed rotatably close to the rear end face of the pressure body, the end of the rotation operating shaft of the face cam is projected toward the inner surface side of the segment, and the face cam is rotated through this rotation operating shaft to rotate the face cam. By pressing the pressing body by a peripheral surface having a large distance from the center of rotation, the pressing body is extruded, and the joining surface of the other segment is pressed at the tip thereof, thereby expanding the segment ring and applying axial force. This Wherein the face cam is locked by a locking device to prevent rotation in the reverse direction, and the segment ring is extended and the axial force is applied.