JPH06193379A - Water stop structure at the starting entrance of the shield machine - Google Patents

Abstract

(57) [Summary] [Purpose] When the entrance packing comes into contact with the segment following the shield machine in order to prevent soil and groundwater from being ejected from the entrance section when starting from the entrance section of the shaft where the shield machine starts. Provided is a water stop structure for a starting entrance of a shield machine, which is excellent in workability and water stop effect without causing reversal. [Structure] The entrance packing 1 provided around the starting mirror section C of the shield machine M provided in the shaft A is aligned with the tops of a plurality of long and short strip-shaped leaf springs 2, 3 and 4 and is converged by the strip plate 5. The outermost leaf spring 2 has a length equal to or longer than that of the entrance packing, and the inner leaf springs 3, 4,
Is fixed by a pressing fixture D that constitutes a biasing member for preventing the leaf spring 2 from reversing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water stop structure for a starting entrance of a shield machine in a shield construction method.

[0002]

2. Description of the Related Art Conventionally, in the shield construction method, a shaft A
The shield machine M penetrates the mirror section C from the starting opening provided in the shaft B of the shaft, and at this time, excavated earth and sand and groundwater flow into the shaft A through the gap between the mirror section C and the shield machine M. In order to prevent this, as shown in FIGS. 1 and 7, an entrance packing a is concentrically arranged on the mirror portion C and is fixed to the mirror portion C by a rectangular presser piece b.

The entrance packing a is arranged in a ring shape along the concentric circumference whose diameter is smaller than the outer diameter of the shield machine M. When the shield machine M starts, the entrance packing a is pressed and bent in the propelling direction. It collides with the outer surface c of the shield machine M and seals the gap d between the mirror section C and the shield machine M to prevent the inflow of excavated earth and groundwater into the shaft. In the figure, e and f are bolts and nuts for tightening the presser foot, and g is a bolt e screwing insert embedded in the shaft B.

Further, a segment N is assembled in the pit behind the shield machine M caused by the excavation of the shield machine M, but the outer diameter of the segment N is smaller than the outer diameter of the shield machine M. At this time, the water pressure inside the shield presses the entrance packing a to the outside to prevent the outflow of earth and sand or groundwater. To prevent this, loosen the bolt e that tightens the presser foot b of the entrance packing a and remove it from the bolt e. Using the elongated slot b ′ formed in the rectangular presser foot b as a guide, the presser foot b is pressed against the outer surface of the segment N and presses the entrance packing a as shown by the dotted line in FIG. Give a water-stopping effect.

FIG. 9 shows another conventional example. The presser foot b of the entrance packing has a shaft e B on which bolts e, nuts f,
A plate h ′ is pivotally supported by a plate h fixed via an insert g via a hinge i, and a rib j serving as a stopper is provided on the back surface of the plate h ′. In this case, when the shield M starts, the entrance packing a is shielded by the shield machine M.
, The outer contour of the shield machine M is pressed against the water pressure, and the outer contour of the segment is automatically crimped as the shield machine M is dug. Prevents reverse rotation by sealing the gap between the mirror, shield machine, and segment.

[0006]

However, in the former case, the entrance packing is bent while being pushed in the propulsion direction with the start of the shield machine, and it advances, but when the step between the shield machine and the segment is reached, The work of pressing the entrance packing by loosening the current position of the press fitting of the entrance packing and using the long slot provided in the press fitting to press the press packing against the outer surface of the segment must be performed all at once. In addition to requiring human labor, the work space below the mirror part is narrow and the work is difficult to perform, and in the case of incomplete construction, earth and sand may gush out.

The latter is intended to improve the above-mentioned problem. In this case, the fixture of the entrance packing is formed by processing two steel plates into a hinge shape, and further fixing one stopper piece to one of the surfaces. Therefore, it is considerably expensive as a single member. In addition, after the work is completed, it must be removed and returned, and in some cases, after removing it, a conventional fixing tool is preliminarily attached to prevent accidents.
There is a problem that the work becomes complicated.

The present invention has been proposed in view of the above problems of the prior art, and its object is to prevent earth and sand from spouting from the entrance when the shield machine starts from the entrance of the shaft. Therefore, when the entrance packing comes into contact with the segment following the shield machine, there is no inversion, the workability is improved, the water blocking effect is excellent, and the blowing of earth and sand or groundwater can be completely sealed. The point is to provide a waterproof structure for the starting entrance of the shield machine.

[0009]

In order to achieve the above-mentioned object, a water stop structure of a starting entrance section of a shield machine according to the present invention has an entrance packing around a starting mirror section of the shield machine provided in a vertical shaft. In the water stop structure of the starting entrance part fixed by a pressing fixture, the pressing fixture is configured by aligning the tops of a plurality of long and short strip-shaped leaf springs and bundling them with a strip plate. The outermost leaf spring has a length equal to or longer than the entrance packing, and the leaf spring adjacent to the inner side of the outermost leaf spring is a biasing member for preventing reversal of the outermost leaf spring. Is configured.

[0010]

Since the present invention is constructed as described above,
When you start the shield machine from the starting mirror section installed in the vertical shaft,
The entrance packing arranged around the starting mirror section and the tops of a plurality of long and short strip-shaped leaf springs are aligned and configured to be converged by a strip plate. The entrance packing is pressed and fixed around the starting mirror section. The entrance packing is pressure-bonded to the outer peripheral surface of the shield machine while pushing the fixture, and the gap between the shield machine and the mirror portion is sealed to prevent inflow of earth and sand or groundwater into the shaft.

When the shield machine further propels and a segment having a smaller diameter appears behind the shield machine and a step is formed, the fixture is instantly contacted with the outer peripheral portion of the segment by the urging force of the strip leaf spring. It is possible to stop contact with soil and groundwater under internal pressure. At this time, while the shield machine is propelled, internal pressure is applied to the strip-shaped leaf spring in the entrance packing, but the intermediate leaf spring attenuates the internal pressure so that the internal pressure applied to the segment is not attenuated so that reversal does not occur. , It is possible to completely seal the discharge of earth and sand and groundwater.

[0012]

The present invention will be described below with reference to the illustrated embodiments. Reference numeral D denotes a pressing fixture for the entrance packing 1, which presses and fixes the entrance packing 1 disposed below the shaft A around the mirror portion C where the shield machine M starts to move.

FIG. 3 shows an embodiment of the pressing fixture D, which is a strip-shaped outer leaf spring 2 having substantially the same length as the entrance packing 1, and a strip-shaped intermediate leaf spring 3 which is shorter than the leaf spring 2. The strip-shaped inner leaf springs 4, which are shorter than the intermediate leaf springs 3, are superposed so that the tops thereof are aligned and converged by the strips 5, and the mounting holes 6 are formed across the strips 5 and the leaf springs 3, 4, 5. It is penetrated.

In the mirror portion C of the vertical shaft wall B, the pressing fixture D is covered with the angle member 7 for covering the corner portion of the mirror portion.
Bolts 8 that come into contact with the mounting holes 6 of the fixture D
Is attached to the insert 9 embedded in the shaft wall B, and the nut 10 is screwed and tightened to the pressing fixture D.
Is attached to the shaft wall B. (See FIG. 4) Reference numeral 11 in the drawing is a washer.

Then, the shield machine M starts to move and digs while pushing the entrance packing 1 and the pressing fixture D. (See FIG. 5) As the excavation by the shield machine M progresses, a segment N appears behind the shield machine M. The outer diameter of the segment N is smaller than that of the shield machine M, and the shield machine M
When a step is created between the leaf spring of the fixture D and the leaf spring of the fixture D, the leaf spring of the fixture D instantaneously abuts on the outer periphery of the segment N by the urging force,
It is possible to seal the earth and sand and the groundwater that are under internal pressure.

At this time, the internal pressure is applied to the leaf springs 4, 3 and 2 during the excavation, but the leaf springs 4 and 3 attenuate the internal pressure and the leaf spring 2
The blowout of earth and sand or groundwater can be sealed by preventing the inversion caused by the decrease of the internal pressure applied to.
(See Figure 6)

[0017]

As described above, according to the present invention, the tops of a plurality of long and short strip-shaped leaf springs are aligned around the starting mirror portion of the shield machine provided in the vertical shaft and are converged by the strip plate. When the shield machine starts from the shaft, the outermost leaf spring is fixed to the entrance packing via a pressing fixture having a length equal to or longer than that of the entrance packing. The leaf spring in the middle of the tool serves as a biasing member for preventing reversal of the outermost leaf spring, so that reversal does not occur when the entrance packing comes into contact with the segment following the shield machine, and discharge of earth and sand or groundwater Is completely sealed, the workability is improved, and the safety is improved, and the water stop structure of the starting entrance of the shield machine is configured.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view showing an outline of a water stop structure of a starting entrance section of a shield machine.

FIG. 2 is a front view showing an embodiment of the water stop structure of the starting entrance section of the shield machine according to the present invention.

FIG. 3 is a perspective view of a pressing fixture of an entrance packing.

FIG. 4 is a vertical cross-sectional side view showing a state immediately before starting from the entrance section of the shield machine, which is an enlarged view of a portion corresponding to a portion a in FIG.

FIG. 5 is a vertical cross-sectional side view showing a state in which the shield machine is excavated and the entrance packing is pressed against the shield machine.

FIG. 6 is a vertical cross-sectional side view showing a state in which the shield machine is further advanced and the entrance packing is pressed against the segment.

FIG. 7 is a vertical sectional side view showing an example of a conventional structure.

FIG. 8 is a front view of a retainer of the entrance packing in FIG. 7.

FIG. 9 is a vertical sectional side view showing another example of the conventional structure.

[Explanation of symbols]

 1 Entrance Packing 2 Outer Leaf Spring 3 Middle Leaf Spring 4 Inner Leaf Spring 5 Strip Plate 6 Mounting Hole 7 Angle Material 8 Bolt 9 Insert 10 Nut 11 Washer A Vertical Shaft B Vertical Shaft C Mirror D Press Fixture M Shield Machine N Segment

Claims (2)

[Claims] 1. In a water stop structure of a starting entrance section, wherein an entrance packing is fixed by a pressing fixture around a starting mirror section of a shield machine provided in a vertical shaft, wherein the pressing fixture has a plurality of long and short strips. Align the tops of the leaf springs,
Of the plurality of leaf springs, the outermost leaf spring has a length equal to or longer than that of the entrance packing and is adjacent to the inner side of the outermost leaf spring. The water stop device for the starting entrance of a shield machine, wherein the spring constitutes a biasing member for preventing reversal of the outermost leaf spring. 2. A plurality of long and short strip-shaped leaf springs are superposed, the tops of the leaf springs are aligned and converged by a strip plate, and vertical shaft wall mounting holes are formed across the strip plate and each of the leaf springs. The water stop structure of the starting entrance part of the shield machine according to claim 1, wherein the entrance packing pressing fixture is configured as described above.