JP3939309B2 - Segmented shaft casing - Google Patents

Description

  The present invention relates to a concrete shaft casing used when building a manhole or the like in the ground, and more particularly to a segment type shaft casing divided in the circumferential direction.

  As a construction method for installing a manhole, a temporary steel pipe shaft is installed, and an assembly-type manhole is installed therein, or concrete is cast on site using the steel pipe shaft as a formwork.

  In addition, recently, concrete casings are rotated or swung all around with a shaft construction machine and pressed into the ground in the same way as steel pipe shafts. Method is used. This method is characterized by fewer steps and a shorter construction period than the method using a temporary steel pipe shaft.

  However, in this method, the concrete casing was directly clamped and fixed with the band of the shaft construction machine, and cracks and chips were generated. Therefore, a concrete casing in which a steel plate is wound around the outer periphery of a concrete casing as disclosed in Patent Document 1 has also been used.

JP 2001-132379 A JP 2001-341115 A JP 2003-213625 A

  However, since the casing for the resisting body disclosed in Patent Document 1 has an integral casing, there are restrictions on transportation, and there is a restriction that only an outer diameter of about 3000 mm or less can be applied.

  In addition, since the upper and lower connections of the casing are bolt connections, it is necessary for a person to enter and connect the casing, and there is a danger when the shaft is deepened. Further, since the rotation or swing torque is received by the bolt, the bolt needs to have sufficient strength to receive the torque.

  In addition, the assembly type manhole generally has a problem that the water stoppage cannot be maintained due to the displacement of the casing due to the ground change such as an earthquake or uneven settlement.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a segmented vertical shaft casing capable of constructing a large manhole, performing a safe connection work, and being resistant to ground fluctuations.

In order to solve the above-mentioned problems, a first configuration of the present invention is a concrete circular casing that is press-fitted into the ground by rotating or swinging around the circumference, and the outer periphery of the casing is a steel plate and is surrounded by a vertical dividing surface. It is a segment type shaft casing made into a segment which can be divided into a plurality of directions.
In this first configuration, a concrete circular casing having a steel plate outer periphery and a segment that can be divided into a plurality of parts in the vertical direction can be divided and transported, and construction of a large casing having an outer diameter of 3000 mm or more is possible. Is also possible.

In the second configuration of the present invention, the connection in the circumferential direction on the vertical dividing surface of the segment is bolted.
In this second configuration, each segment can be formed into a circular casing having water-stopping properties by applying a water-stopping material such as caulking to the joining surface in the longitudinal direction and joining them with bolts.

According to a third configuration of the present invention, the upper and lower joints of the segments are provided with water stop grooves so as to form a ring shape when the segments are assembled in the circumferential direction, and the water stop grooves of the upper and lower segments to be joined are provided. A water stop ring is provided.
In this third configuration, a groove is provided at the upper and lower joints of the segment so as to form a ring when the segment is assembled, and a ring-shaped water stop ring (such as rubber) is provided across the upper and lower segment grooves. Therefore, it is possible to easily close the gap between the stacked circular casings with the water-stop ring, so that it is possible to obtain flexibility and water-stopping without performing the work of filling the joint material or the like into the gap. it can. Moreover, even if the casing shifts due to ground change such as an earthquake, the water stoppage can be maintained by the deformation of the water stop ring.

According to a fourth configuration of the present invention, the segments are assembled into a plurality of circular casings, and the upper and lower sides of the circular casings are connected by welding the outer peripheral steel plates.
According to a fifth configuration of the present invention, the vertical dividing surfaces of the segments are joined by welding steel plates on the outer periphery of the circular casing.

  By these fourth and fifth configurations, the upper and lower sides of the assembled circular casing can be joined from the outside of the casing by welding the outer peripheral steel plates, so that a person needs to enter the casing Therefore, it is safe and the rotational or swinging torque can be transmitted over the entire outer peripheral steel plate, so that no uneven load due to the torque is applied to the internal concrete.

  According to the present invention, it is possible to construct a large manhole by making the outer periphery a steel plate with a segment that can be divided into a plurality of segments in the circumferential direction. In addition, the upper and lower connections of the circular casing assembled with the segments are performed by welding the outer peripheral steel plates, so that the connection work is safe and torque can be transmitted without applying a load to the concrete inside. In addition, by providing a water stop ring (rubber or the like) over the upper and lower casings in the upper and lower connections, a manhole resistant to ground fluctuation can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
FIG. 1 shows a segment type shaft casing according to the present invention, (a) is a plan view, (b) is a cross-sectional view taken along the line A-A in FIG. (A) is a top view, (b) is a front view. 3 is an enlarged view of the circumferential connection portion, (a) is a cross-sectional view, and (b) is a BB cross-sectional view of (a). FIGS. 4A and 4B are enlarged views showing the knock pin mounting hole, where FIG. 4A is a plan view and FIG. 4B is a cross-sectional view taken along the line C-C in FIG. 5A and 5B show a water stop ring attachment diagram, wherein FIG. 5A is an enlarged sectional view of the attached state, and FIG. 5B is a sectional view showing a state at the time of ground change. FIG. 6 is a half cross-sectional view of the shaft casing connected in the vertical direction. 7A and 7B are enlarged views of the water stop groove and the water stop ring, where FIG. 7A is a cross-sectional view of the water stop groove, and FIG. 7B is a cross-sectional view of a state where the water stop ring is attached to the water stop groove. FIG. 8 is an explanatory view showing an apparatus for excavating a shaft using a tubing device.

  In this embodiment, a shaft casing is formed by joining semi-cylindrical segments that can be divided into two. In the figure, a shaft casing 1 is composed of semi-cylindrical segments 1A and 1B. Each segment 1A, 1B comprises a semi-cylindrical concrete 2 and a steel plate 3 covering the outer periphery of the concrete 2. I have.

Further, in this example, circumferential connection fittings 6 are fixedly embedded in the concrete 2 at three locations, upper, middle, and lower, on the vertical dividing surface, and the segments 1A and 1B are joined by circumferential connection bolts 7. (See FIG. 3). Thereby, the segments 1A and 1B are assembled in a cylindrical shape, and the water-stopping action is maintained by applying a water-stopping material such as coking to the joint surface.
A semicircular water stop groove 8 that forms a ring shape when assembled as the casing 1 is formed at the upper and lower joints of the segments 1A and 1B, and a water stop ring 9 is attached thereto (see FIG. 5). ).

  In addition, in this example, the upper and lower joints of the segments 1A and 1B are provided with knock pin mounting holes 10 at positions where the circumference is divided into four, and the knock pins 11 are provided so as to straddle the knock pin mounting holes 10 of the upper and lower casings 1. Installed. Thereby, it can be set as the positioning at the time of joining the casing 1 to the vertical direction.

  The casing 1 is added as the shaft excavation progresses. When the addition is performed, the seams of the steel plates 3 on the outer periphery of the upper and lower casings 1 are welded to form the entire circumference welded portion 12.

As shown in FIG. 7, the water stop groove 8 described above includes a mounting hole 8a having a circular cross section and an opening 8b tapered toward the mounting hole 8a in order to open the mounting hole 8a to the outside. . The head portion at the boundary between the mounting hole 8a and the closed portion 8b is a constricted portion 8c.
In the water stop groove 8, a side portion of the water stop ring 9 for closing a gap between the casings 1 is inserted when the casing 1 is installed in an overlapping manner.

  The water stop ring 9 is formed in a band shape by an elastic body such as rubber. Engaging portions 9a that are inserted into and attached to the mounting holes 8a of the water-stop groove 8 are provided at both the left and right ends of the water-stop ring 9, and the inner surface of the opening 8b is provided at a position located in the opening 8b. A plurality of oblique lip portions 9b that are pressed against each other are provided. Furthermore, a substantially U-shaped expansion / contraction part 9c is provided at the center of the water stop ring 9, and the width of the water stop ring 9 changes as the expansion / contraction part 9c expands and contracts.

  In order to join the two upper and lower casings 1 with the water stop ring 9, after injecting caulking material into the water stop grooves 8, 8 of the two casings 1, the engaging portions 9 a on the left and right side portions of the water stop ring 9. , 9a are inserted into the mounting holes 8a, 8a from the openings 8b, 8b of the two casings 1.

  When the caulking material is cured, the engaging portion 9a is joined to the constricted portion 8c so as not to come out of the mounting hole 8a, the water stop ring 9 can be expanded and contracted in the width direction, and the lip portion 9b is formed in the opening portion 8b. Performs water-stopping action by pressing against the inner surface.

  A shaft excavation method using the segment type shaft casing according to the embodiment having the above configuration will be described with reference to FIG. FIG. 8 shows an apparatus for excavating a shaft using a tubing device (a shaft construction machine).

  First, the casing 1-1 at the front end in which the segments 1A and 1B are joined in advance is attached to the tubing device 20 fixed by the base machine 23, and the cylindrical casing 1- is used by using a rotary motor (not shown) and a press-fitting cylinder 21. Excavating with the excavating blade 13 at the tip while rotating and press-fitting 1. The excavated earth and sand are discharged to the outside by the grab bucket 24 at the tip of the base machine 23.

  When excavation progresses and the upper part of the casing 1-1 is close to the upper part of the tubing device 20, a water stop ring 9 is attached to the water stop groove 8 to add the next casing 1-2, and the upper and lower casings 1-1 and 1 are connected. -2 welds the seam of the outer peripheral steel plate 2 to form the entire circumference welded portion 12. The cylindrical casing 1 is added according to the depth of the shaft, and excavation is performed to a predetermined depth.

  Thus, a shaft can be constructed using the segment type shaft casing 1 of the present embodiment.

  INDUSTRIAL APPLICABILITY The present invention can be used in the field of shaft excavation work such as manholes as a segmented shaft casing capable of constructing large manholes, enabling safe connection work, and resistant to ground fluctuations.

The segment type shaft casing which concerns on embodiment of this invention is shown, (a) is a top view, (b) is AA sectional drawing of (a). The shape of the 2-part dividing-type segment which concerns on embodiment of this invention is shown, (a) is a top view, (b) is a front view. It is an enlarged view of the circumferential direction connection part which concerns on embodiment of this invention, (a) is a cross-sectional view, (b) is BB sectional drawing of (a). It is an enlarged view which shows the knock pin attachment hole which concerns on embodiment of this invention, (a) is a top view, (b) is CC sectional drawing of (a). The water stop ring attachment drawing which concerns on embodiment of this invention is shown, (a) is an expanded sectional view of an attachment state, (b) is sectional drawing which shows the state at the time of ground change. It is a half sectional view of a state where a shaft casing is connected in the vertical direction according to the embodiment of the present invention. It is an enlarged view of a water stop groove and a water stop ring concerning an embodiment of the invention, (a) is a sectional view of a water stop groove, (b) is a sectional view in the state where a water stop ring was installed in a water stop groove. It is. It is explanatory drawing which shows the apparatus which excavates a shaft using a tubing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shaft casing 1A, 1B Segment 2 Concrete 3 Steel plate 6 Circumferential connection metal fitting 7 Circumferential connection bolt 8 Water stop groove 8a Mounting hole 8b Opening part 8c Constriction part 9 Water stop ring 9a Engagement part 9b Lip part 9c Expansion / contraction part 10 Knock pin Mounting hole 11 Dowel pin 12 Welded part of entire circumference 13 Cutting edge 20 Tubing device 21 Press-in cylinder 23 Base machine 24 Grab bucket

Claims (4)

In a concrete circular casing that is press-fitted into the ground by rotating or swinging around the circumference, the outer periphery of the casing is a steel plate, a segment that can be divided into a plurality of circumferential directions by a vertical dividing surface, and the segments are assembled in the circumferential direction. A plurality of circular casings, and the upper and lower sides of the circular casings are connected by welding the outer peripheral steel plates .   The segment type shaft casing according to claim 1, wherein a connection in a circumferential direction on a vertical dividing surface of the segment is a bolt joint.   The upper and lower joints of the segments are provided with a water stop groove so as to form a ring when the segments are assembled in the circumferential direction, and a water stop ring is provided over the water stop grooves of the upper and lower segments to be joined. The segment type shaft casing according to claim 1 or 2. The segment-type shaft casing according to any one of claims 1 to 3 , wherein the vertical dividing surfaces of the segments are joined by welding steel plates on the outer periphery of the circular casing.

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