JP5393319B2 - Gripping member - Google Patents

Description

  The present invention relates to a gripping member, and more particularly to a gripping member that is attached to a concrete member such as a segment and attaches a hanging metal fitting that suspends the concrete member.

  In general, when building a tunnel with a shield machine, the segments are assembled with an erector mounted on the shield machine while the ground is being excavated with the shield machine, and the inner wall surface of the excavated part is covered with the segment. ing.

  In the segment used for such tunnel lining work, a cylindrical gripping member (gripping hardware) is embedded in the center, and the suspension bracket is inserted into the segment by fitting the suspension bracket to the gripping member. The segment can be attached to the erector.

  An example of the gripping member is shown in FIG. This gripping member 21 is provided with a female thread portion 23 on the inner surface of a thick steel pipe 22, and an anchor bar 24 is wound around the outer peripheral surface of the rear side end in the longitudinal direction of the thick wall steel pipe 22. The outer peripheral surface of the steel plate 22 is integrally fixed by welding, and the opening end surface of the thick-walled steel pipe 22 is usually attached with a cap that closes the opening after the segment is assembled. After the attachment, the cap head is embedded in a space having a truncated cone shape in the thickness direction from the surface 16 so that the head of the cap is flush with the surface 16 of the segment 15.

  FIG. 21 shows another example of the gripping member. This gripping member 25 is made of cast iron, and has a cylindrical portion 26 provided with an internal thread portion 27 on the inner surface, and an annular shape integrally provided on the outer peripheral surface of the longitudinal end of the cylindrical portion 26 in the longitudinal direction. The opening end surface of the cylindrical portion 26 is usually provided with a cap that closes the opening after the segment assembly. After the attachment, the cap head is embedded in a space having a truncated cone shape in the thickness direction from the surface 16 so that the head of the cap is flush with the surface 16 of the segment 15.

  Further, another example of the gripping member is described in Patent Document 1. This gripping member is a molded product made of fiber reinforced resin, and has a cylindrical main body in which annular projections are provided in multiple stages on the outer surface and female threads are provided on the inner surface, and this main body is embedded in a segment. Yes.

JP 11-270291 A

  By the way, in the gripping members 21 and 25 described in FIGS. 20 and 21, a hanging bracket (not shown) is fitted to the gripping members 21 and 25, and the segment 15 is suspended via the hanging bracket ( Top) When pulling up, it is necessary to have a resistance to prevent the hanging bracket from coming out against a tensile force applied to the holding members 21 and 25 and a fixing force to prevent the holding members 21 and 25 themselves from coming out of the segment 15. Therefore, the screw to be fitted is a trapezoidal screw that requires a thick wall thickness. Alternatively, in order to fix, in the case of the gripping member 21, the anchor bars 24 are wound as described in “paragraph 0004”, and the gripping member 25 is provided with an annular flange 28 as described in “paragraph 0005”. Accordingly, the gripping members 21 and 25 are pulled out from these portions at the cone-shaped portion A in FIGS. 20 and 21 so as to achieve close contact. Each increases the weight of the gripping members 21 and 25. In the gripping member 21, in addition to threading of an extremely thick steel pipe, the material and welding of the anchor bars 24, and in the gripping member 25, the cylindrical portion 26 of the screw portion 27 and the annular flange 28 are integrally formed. It is molded by casting. In both cases, the production takes time and the weight is heavy, so the workability when embedding the gripping members 21 and 25 in the segment 15 is deteriorated, and the production cost of the segment 15 is increased.

  On the other hand, the gripping member described in Patent Document 1 does not cause a weight problem as in the gripping members 21 and 25 shown in FIGS. 20 and 21, but is made of synthetic resin and thus has poor fire resistance. Since the adhesion to the water is worse than that of iron, water leakage may occur, and the usable environmental conditions are limited to a narrow range.

  The present invention has been made in view of the conventional problems as described above, and provides a gripping member that can reduce the production cost of a segment and that is not limited to a narrow range of usable environmental conditions. For the purpose.

In order to solve the above problems, the present invention employs the following means.
That is, the present invention is a steel gripping member embedded in a concrete member and fitted with a hanging metal fitting inside, and an internal thread portion for fitting the male screw portion of the hanging metal fitting is formed on the inner surface. It has a cylindrical main body part formed with an uneven part corresponding to the female screw part on the outer surface, and the base end of the main body part is located at a position away from the surface of the concrete member by a predetermined distance in the depth direction. Further, it is embedded in the concrete member.

According to the gripping member of the present invention, the concrete member is suspended via the suspension fitting by fitting the suspension fitting to the main body portion and screwing the male screw portion of the suspension fitting and the female screw portion of the main body portion. Can do.
In this case, the tensile force applied to the main body portion can be resisted by the adhesion force of the uneven portion on the outer surface side of the main body portion to the concrete and the shear resistance force between the uneven portion and the concrete. Also, with respect to the tensile force from the hanging bracket, the tensile force is transmitted to the concrete via the male threaded portion of the hanging bracket, the female threaded portion on the inner surface of the main body portion, and the uneven portion on the outer surface side of the main body portion. Can be resisted by the support pressure generated in
Therefore, since it is not necessary to increase the thickness of the main body in order to resist the tensile force, the weight of the main body can be reduced, and the workability when embedded in a concrete member can be improved. The manufacturing cost of the concrete member can be reduced.

  In the present invention, the base end of the main body may be integrally provided with a cylindrical or tapered cylindrical screw introduction portion with no irregularities on the inner and outer surfaces.

  According to the gripping member of the present invention, the tensile force applied to the main body can be resisted by the adhesion force of the outer surface of the screw introduction portion to the concrete. In addition, a suspension fitting is fitted to the main body, the concrete member is suspended by the suspension fitting, and after the assembly of the concrete member is completed, a cap is attached to the screw introduction portion to close the opening of the concrete member. It is possible to improve the appearance of the concrete member.

  Furthermore, in the present invention, between the surface of the concrete member and the base end of the main body part, or between the surface of the concrete member and the screw introduction part, the base end of the main body part or the screw introduction It is good also as providing the escape part which consists of a cylindrical or frustoconical space larger diameter than the cap attached to a part.

According to the gripping member of the present invention, when the hanging metal fitting is fitted to the main body portion and the concrete member is suspended by the hanging metal fitting, the main body portion and the concrete member are separated by the escape portion formed of a columnar or frustoconical space. It is possible to prevent cracks from occurring between the surfaces or between the screw introduction portion and the surface of the concrete member.
In this case, the depth of the escape portion is set to a depth corresponding to the height of the head portion of the cap attached to the main body portion or the screw introduction portion, or to increase the fixing force of the gripping member to the concrete member. In addition, the depth of the escape portion is set to be deeper than the height of the head portion of the cap. By setting the depth of the escape portion deeper than the height of the head of the cap, the uneven portion of the main body that transmits stress from the hanging bracket to the concrete member is buried deeply. The fixing force can be increased by the same effect as the principle that the fixing force increases as the shape portion increases, and cracks can be effectively prevented from occurring in the concrete member.

  Further, in the present invention, the main body portion and the screw introduction portion are provided with a fitted portion that is recessed radially outward, and a cap that is attached to the main body portion and the screw introduction portion on the fitted portion. It is good also as a fitting part being fitted.

  According to the gripping member of the present invention, the cap is fixed in a state of being attached to the main body portion and the screw introduction portion by fitting the fitting portion of the cap to the fitted portion of the main body portion and the screw introduction portion. .

  Furthermore, in the present invention, the concrete member may be a segment.

  In this case, for example, the segment is made of steel fiber reinforced concrete having higher tensile strength than normal concrete, so that the grip member smaller than the grip member used for the normal concrete segment having the same size and weight can be used. It becomes possible.

  As described above, according to the gripping member of the present invention, it is not necessary to increase the wall thickness in order to resist the tensile force, and the weight can be reduced. The workability to embed can be improved, and the production cost can be reduced.

It is the schematic sectional drawing which showed the whole 1st Embodiment of the holding member by this invention. It is a top view of a hanging metal fitting. It is the schematic sectional drawing which showed the whole concrete member which attached the hanging metal fitting. FIG. 4 is a partially enlarged view of FIG. 3. It is a top view of a segment specimen. FIG. 6 is a front view of FIG. 5. FIG. 6 is a right side view of FIG. 5. It is the schematic sectional drawing which showed the whole 2nd Embodiment of the holding member by this invention. It is sectional drawing of FIG. FIG. 9 is a partial perspective view of FIG. 8. It is a front view of the hanging metal fitting used for 2nd Embodiment. It is sectional drawing of FIG. It is the schematic sectional drawing which showed the whole 3rd Embodiment of the holding member by this invention. It is sectional drawing of FIG. FIG. 14 is a partial perspective view of FIG. 13. It is the schematic sectional drawing which showed the modification of 3rd Embodiment. It is the schematic sectional drawing which showed the whole 4th Embodiment of the holding member by this invention. It is sectional drawing of FIG. It is the schematic which showed the whole hanging bracket used for 4th Embodiment. It is the schematic which showed an example of the conventional holding member. It is the schematic which showed the other example of the conventional holding member.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show a first embodiment of a gripping member according to the present invention. 1 is a schematic sectional view showing the entire gripping member, FIG. 2 is a plan view of the hanging bracket, FIG. 3 is a schematic sectional view showing the entire concrete member (segment) to which the hanging bracket is attached, and FIG. 4 is a portion of FIG. It is an enlarged view.

  That is, the gripping member of the present invention can be applied when various concrete members are suspended by the hanging metal fittings. In this embodiment, as shown in FIGS. 3 and 4, the inner wall surface of the tunnel is used. This is applied to the case where the concrete segment 15 used for the lining is hung by the hanging bracket 10.

  A concrete segment (hereinafter referred to as “segment 15”) has a gripping member 1 according to the present embodiment embedded in the center thereof, and a hanging metal fitting 10 is attached to the gripping member 1. In the present embodiment, for example, a segment 15 having a weight of 8 to 10 tons is assumed.

  The gripping member 1 is formed by machining or the like using a thin-walled steel pipe (for example, a carbon steel pipe for machine structure (STKM11A)), and as shown in FIG. A cylindrical main body 2 in which the concave and convex portion 4 having a shape corresponding to the groove of the female screw portion 3 is formed on the outer surface, and a tube having no irregularities on the inner and outer surfaces provided integrally with the base end 3a of the female screw portion 3 of the main body 2 And a cylindrical extra length portion 7 with no irregularities on the inner and outer surfaces, which are integrally provided at the terminal end 3b of the female screw portion 3 of the main body portion 2. Note that the screw introduction portion 5 may have a tapered cylindrical shape that gradually increases in diameter toward the upper end.

  As shown in FIG. 4, the male screw portion 11 of the hanging bracket 10 is screwed into the female screw portion 3 on the inner surface of the main body portion 2 of the gripping member 1. In addition, the internal thread part 3 of the main-body part 2 has preferable trapezoidal screw shape which is excellent in shear strength.

  On the inner surface of the screw introduction portion 5, an annular concave portion 6 that is a radially engaged portion, which is a fitted portion, is provided, and in this concave portion 6, the frustoconical space portion 17 of the segment 15 or the entrance of the gripping member 1. The cap can be fixed to the space portion 17 of the segment 15 by fitting a projection which is a fitting portion of a cap (not shown) that closes the cap. In addition, the recessed part 6 may be trapezoidal screw shape.

  The extra length portion 7 is for avoiding interference between the internal thread portion 3 on the inner surface of the main body portion 2 and the incomplete thread portion at the distal end portion of the external thread portion 11 of the hanging bracket 10, as shown in FIG. When the male threaded portion 3 of the hanging bracket 10 is screwed into and fitted to the female threaded portion 3 on the inner surface of the main body 2, the incomplete threaded portion at the tip of the male threaded portion 11 of the hanging bracket 10 is connected to this extra length portion 7. Is supposed to be missed. Further, the surplus length portion 7 serves as an attachment port for a cap (not shown) for preventing the concrete from flowing into the gripping member 1.

  As shown in FIGS. 3 and 4, the gripping member 1 has a segment 15 in which the axis line is oriented in the thickness direction of the segment 15 and the base end 3 a of the female screw portion 3 of the main body 2 is a segment. 15 is embedded in the segment 15 so as to be located at a predetermined distance from the surface 16 of the 15 in the thickness direction.

  As shown in FIG. 4, an escape portion 18 that is a frustoconical space is provided between the upper end (tip) of the screw introduction portion 5 of the gripping member 1 and the surface 16 of the segment 15. The escape portion 18 is formed on a tapered surface 18a having an inner peripheral surface of 5 ° or more, and the upper end of the screw introduction portion 5 of the gripping member 1 is continuously arranged at the lower end of the tapered surface 18a. Between the upper end of the screw introduction portion 5 and the surface 16 of the segment 15. When the hanging bracket 10 is attached to the gripping member 1 and the segment 15 is suspended via the hanging bracket 10 by the relief portion 18, a crack is generated on the surface 16 side of the segment 15 due to the tensile force from the hanging bracket 10. Can be prevented.

  In the present embodiment, the escape portion 18 is configured by a truncated cone space, but the escape portion 18 may be configured by a cylindrical space. In short, a space having a predetermined length may be formed between the base end 3 a of the female screw portion 3 of the gripping member 1 and the surface 16 of the segment 15.

  The hanging bracket 10 is inserted into the inside of the gripping member 1 from the surface 16 side of the segment 15 in which the gripping member 1 of the present embodiment configured as described above is embedded, and the male thread portion 11 of the hanging bracket 10 is connected to the body of the gripping member 1. The hanging bracket 10 can be attached to the gripping member 1 by being screwed into and fitted into the female screw portion 3 on the inner surface side of the portion 2.

  Then, the segment 15 is attached to the erector of the shield machine through the hanging metal fitting 10 and the erector is operated to assemble the segment 15 on the inner wall surface of the ground excavated by the shield machine, and the inner wall surface is covered by the segment 15 can do.

  In the gripping member 1 according to the present embodiment described above, when the segment 15 is suspended via the hanging bracket 10, the tensile force applied to the gripping member 1 is on the outer surface side of the main body 2. Resistance can be achieved by the adhesion force of the uneven portion 4 to the concrete and the shear resistance force between the uneven portion 4 and the concrete. Moreover, with respect to the tensile force from the hanging bracket 10, the tensile force is applied to the concrete via the male screw portion 11 of the hanging bracket 10, the female screw portion 3 on the inner surface of the main body portion 2, and the uneven portion 4 on the outer surface side of the main body portion 2. It can be transmitted and resisted by the support pressure that occurs between them.

  Therefore, since it is not necessary to make the gripping member 1 very thick as in the prior art in order to resist the tensile force, the gripping member 1 can be reduced in weight. In addition, the workability when embedding in the space can be improved, and the manufacturing cost of the segment 15 can be greatly reduced because the price is low. Moreover, the weight reduction of the members leads to resource saving and contributes to the prevention of global warming.

  8 to 12 show a second embodiment of a gripping member according to the present invention. The gripping member 1 according to the present embodiment is provided with female screw portions 3c and non-screw portions 3d alternately at intervals of 120 ° in the circumferential direction on the inner surface side of the main body portion 2, and on the outer surface side of the main body portion 2. The uneven portion 4a having a shape corresponding to the female screw portion 3c and the non-recessed portion 4b having a shape corresponding to the non-threaded portion 3d are alternately provided at intervals of 120 ° in the direction. This is the same as that shown in the embodiment.

  Further, as shown in FIGS. 11 and 12, the hanging metal fitting used for the gripping member 1 of the present embodiment corresponds to the female screw portion 3 c and the non-screw portion 3 d on the inner surface side of the main body portion 2 of the gripping member 1. Thus, it is set as the shape which alternately provided the external thread part 11a and the non-screw part 11b for every 120 degree interval in the circumferential direction.

And in order to attach the hanging metal fitting 10 to the holding member 1 of the above structure, the non-threaded part 11b and the male screw part of the hanging metal fitting 10 are positioned at the positions of the female screw part 3c and the non-screw part 3d of the main body part 2 of the holding member 1. 11a, and in this state, the suspension fitting 10 is inserted into the main body 2 of the gripping member 1 as far as it will go, and the suspension fitting 10 is turned by 60 ° so that the male thread 11a of the suspension fitting 10 is the female thread 3c of the gripping member 1. Can be engaged.
Although not shown, a plurality of full-circle screws may be provided at the base end of the hanging bracket 10. In that case, after inserting the hanging metal fitting 10 into the inside of the main body 2 of the gripping member 1, the hanging metal fitting 10 may be rotated by the number of threads of the entire circumference screw portion.

  Even in the gripping member 1 according to the present embodiment configured as described above, the same effects as those shown in the first embodiment can be obtained, and when the hanging bracket 10 is attached to the gripping member 1, Since it is only necessary to insert the hanging bracket 10 into the inside of the gripping member 1 and rotate it by 60 °, the workability of attaching the hanging bracket 10 to the gripping member 1 can be improved.

A third embodiment of a gripping member according to the present invention is shown in FIGS. The gripping member 1 of the present embodiment is provided with a concavo-convex portion 4c in a portion corresponding to the non-concave portion 3d on the outer surface side of the main body portion 2, and further provided with a screw portion 6a on the inner surface of the screw introduction portion 5. The cap-side threaded portion is configured to be fitted to 6a, and the other configurations are the same as those shown in the second embodiment.
In addition, as shown in FIG. 16, you may comprise so that the recessed part 6 may be provided in the inner surface of the screw introduction part 5 instead of the screw part 6a, and the protrusion by the side of a cap may be fitted in this recessed part 6. FIG.

  And even if it exists in the holding member 1 of this Embodiment, there exists an effect similar to what is shown in the said 2nd Embodiment, and the uneven | corrugated | grooved part 4c is provided in the non-uneven | corrugated | grooved part 3d of the outer surface side of the main-body part 2. Since it has provided, the adhesiveness of the main-body part 2 of the holding member 1 and concrete can be improved.

  17 to 19 show a fourth embodiment of a gripping member according to the present invention. The gripping member 1 according to the present embodiment is provided with a female screw portion 3c over the entire circumference at the front end portion on the inner surface side of the main body portion 2, and a concavo-convex portion 4a over the entire circumference at the front end portion on the outer surface side of the main body portion 2 corresponding thereto. The other configurations are the same as those shown in the third embodiment.

  Further, as shown in FIG. 19, the suspension fitting 10 used for the gripping member 1 of the present embodiment has a plurality of full-circle screws provided at the base end portion. After being inserted into the inside of the portion 2, it is necessary to rotate the hanging bracket 10 by the number of the entire circumference screw.

  And even if it exists in the holding member of this Embodiment, there exists an effect similar to what is shown in the said 3rd Embodiment.

Next, the result of the pull-out test of the holding member according to the present invention will be shown.
(1) Gripping member As shown in FIG. 1, the gripping member 1 is made of a material: STKM11A, thickness (t): 1.5 mm, outer diameter (R1); 86 mm inner diameter (R2); 83 mm, full length (l); 155 mm, cap mounting part length (l1): 50 mm, body part (female thread part) length (l2); 95 mm, 80 mm, extra length part length (l3); 10 mm, female thread part; male thread part of the hanging bracket (trapezoidal screw; Tr82 × P10) can be fitted.

(2) Segment specimen As shown in FIGS. 5 to 7, the segment specimen 15 has a thickness (h): 400 mm, a width (b): 1000 mm, and a length (l) 1300 mm. The member 1 was embedded in the central portion, and a relief portion 18 that was a truncated cone-shaped space was provided between the tip of the gripping member 1 and the surface 16 of the segment specimen 15. As shown in FIG. 4, the escape portion 18 is a frustoconical space having a depth (h1): 75 mm, an outer diameter: 110 mm, an inner diameter: 95 mm, and the main body of the gripping member 1 from the surface 16 of the segment specimen 15. The distance (h1 + l1) to the base end 3a of the female screw part 3 of the part 2 was set to 125 mm. As the concrete, steel fiber reinforced high-fluidity concrete having a design standard strength f′ck = 42 N / mm ² was used, and eight D16 bars were arranged vertically as main reinforcing bars.

(3) Test method Using a φ82 mm extraction jig (hanging bracket 10) processed into a trapezoidal screw (see FIGS. 2 and 4), a extraction test was performed using a center hole jack. The support span was assumed to be 700 mm assuming the interval between the auxiliary jacks of the erector, and the pulling force was applied with a loading pitch of 20 kN.

ここで、実かん合長は、引抜き治具（吊金具１０）と把持部材１とのねじ部（雄ねじ部１１及び雌ねじ部３）のとり合い長を示している。ケース２−１では、把持部材１を完全に引き抜き、ケース２−２では、把持部材１の挿入量（実かん合長さ）を減じて実施した。
ひび割れ発生荷重は、ケース１で最小で４００ｋＮ、ケース２−２のかん合長を減じたケースでも３６０ｋＮであった。いずれのケースも把持部材１からセグメント供試体１５の幅方向にひび割れが発生した。
引抜き耐力は、ケース１の最小で５９７ｋＮ、ケース２−１で５０６ｋＮ、ケース２−２で４０２ｋＮであった。実嵌合長が長くなるほど引抜き耐力が増加する傾向が見られた。 (4) The results of the pull-out test are shown in Table 1.

Here, the actual engagement length indicates the length of engagement of the threaded parts (the male threaded part 11 and the female threaded part 3) between the drawing jig (hanging bracket 10) and the gripping member 1. In case 2-1, the gripping member 1 was completely pulled out, and in case 2-2, the insertion amount (actual engagement length) of the gripping member 1 was reduced.
The crack generation load was 400 kN at the minimum in case 1 and 360 kN even in the case where the mating length of case 2-2 was reduced. In any case, cracks occurred in the width direction of the segment specimen 15 from the holding member 1.
The pull-out strength was 597 kN at the minimum for Case 1, 506 kN for Case 2-1, and 402 kN for Case 2-2. There was a tendency for the pulling strength to increase as the actual fitting length increased.

  When the weight of the segment 15 is 8 tons (safety factor 5 times) to 10 tons (safety factor 4 times), any of the cases 1-1 to 2-2 has sufficient pulling strength. As can be seen, it has been proved that the gripping member 1 of the present invention is effective, the safety at the time of assembling the segment 15 can be ensured, and it is confirmed that the large-sized segment 15 can be applied.

In each of the above embodiments, the gripping member 1 according to the present invention is applied to the concrete segment 15, but the gripping member 1 according to the present invention may be applied to the steel fiber reinforced concrete segment 15. In that case, it is possible to cope with the gripping member 1 smaller than the concrete segment 15 having the same size and weight, and the manufacturing cost of the segment 15 can be reduced.
Furthermore, the gripping member 1 according to the present invention may be applied not only to the segment 15 but also to other concrete members.

DESCRIPTION OF SYMBOLS 1 Holding member 2 Main body part 3 Female thread part 3a Base end 3b Termination 3c Female thread part 3d Non-screw part 4 Uneven part 4a Uneven part 4b Non-uneven part 4c Uneven part 5 Screw introduction part 6 Recessed part 7 Extra length part 10 Suspension bracket 11 Male screw part 11a Male thread part 11b Non-screw part 15 segment (segment specimen)
16 Surface 17 Space 18 Escape 18a Tapered surface
21 Gripping Member 22 Thick Steel Pipe 23 Female Threaded Part 24 Anchor Muscle 25 Gripping Member 26 Tubular Part 27 Female Threaded Part 28 Flange A Cone Part

Claims (6)

A steel gripping member embedded in a concrete member and fitted with a hanging metal fitting inside,
An internal thread portion is formed on the inner surface to fit the male thread portion of the suspension fitting, and an outer surface has a cylindrical main body portion on which an uneven portion corresponding to the female thread portion is formed.
A gripping member embedded in the concrete member such that a base end of the main body portion is located at a position away from the surface of the concrete member in a depth direction by a predetermined distance.   The grip member according to claim 1, wherein a cylindrical or tapered cylindrical screw introduction portion having no irregularities on the inner and outer surfaces is integrally provided at a proximal end of the main body portion. Between the surface of the concrete member and the base end of the main body portion, a relief portion made of a columnar or frustoconical space having a larger diameter than the base end of the main body portion is provided. The holding member according to claim 1. Between the surface and the thread introducing portion before Symbol concrete member, that the relief portion is provided comprising a cylindrical or space frustoconical having a diameter larger than the cap attached to the front Symbol screw insertion part The holding member according to claim 2 , wherein The body portion and the screw introduction portion are provided with a fitted portion that is recessed radially outward, and the fitting portion of the cap attached to the body portion and the screw introduction portion is fitted to the fitted portion. The holding member according to claim 2 or 4 , wherein the holding member is formed. Said concrete member, the gripping member according to any one of claim 1 to 5, characterized in that a segment.

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