JP4445905B2 - Water stop structure and water stop method - Google Patents

Description

  The present invention relates to an elastic body for water stop in a structure using a tension material (PC steel material) such as a ground anchor, a water stop structure using the same, and a water stop method. In particular, an elastic body for water stop that restricts the movement of fluid such as grout from the gap between each tension member arranged in a structure using the tension member and the fixing member of the tension member, and water stop using the same It relates to the structure and water stop method.

  A structure using a tension material such as PC steel is required to have a water-tightness in the construction process. Examples of the portion requiring water-stopping in a structure using a tendon include a fixing portion of a ground anchor and an exit portion of a bridge saddle.

  Examples of the water stop structure in the fixing portion of the ground anchor include those described in Patent Document 1. FIG. 3 is a schematic view of a water stop structure in the fixing unit. The fixing unit includes an anchor plate 240, an anchor head 220, and a wedge 210. The tensioned PC steel material 270 is inserted into the insertion hole of the anchor head 220 and is gripped by the wedge 210, whereby the tension force is transmitted to the slope via the wedge 210, the anchor head 220, and the anchor plate 240. Further, the grout is filled in the hole 280 in which the PC steel material 270 is arranged. The water stop structure consists of an anchor head 220, an elastic body 200, a steel disc 250, and a tightening mechanism (screw 260). The elastic body 200 and the steel disc 250 are similar to the anchor head 220. An insertion hole through which the PC steel material 270 is inserted is provided. Specifically, the elastic body 200 is sandwiched between the anchor head 220 and the rigid disc 250, and the elastic body 200 is compressed in the longitudinal direction of the PC steel material 270 by tightening the screws 260. The diameter of the insertion hole is made small. By reducing the diameter of the insertion hole in the inner circumferential direction in this way, the PC steel material 270 and the elastic body 200 are brought into close contact with each other in the insertion hole of the elastic body 200, and the grout filled in the drilling hole 280 is formed in the hole 280. The PC steel 270 and the anchor head 220 are not leaked to the surface side of the anchor head 220.

  As the water stop structure at the exit of the bridge saddle, the one described in Patent Document 2 can be cited. FIG. 4 is a schematic view of a water stop structure at the outlet portion. The water stop structure is integrally formed by a tightening mechanism (screw 360) by contacting the spacer 320, the fastening plate 330, the elastic body 300, and the presser plate 350 in this order from the end of the steel pipe 310. The resin 340 filled in the provided resin filling portion prevents the grout disposed in the steel pipe 310 from leaking. Each member of the water stop structure has an insertion hole for inserting the PC steel material 370. By tightening the screw 360, the elastic body 300 is compressed and deformed so that the PC steel material 370 and the elastic body 300 are in close contact with each other. A gap formed between the elastic body 300 is filled. As described above, in Patent Document 2, the gap between the PC steel 370 and the elastic body 300 is sealed by the deformation of the elastic body 300 to prevent the resin 340 from leaking between the retaining plate 330 and the PC steel 370. Furthermore, the grout in the steel pipe 310 is prevented from leaking from the gap between the holding plate 350 and the PC steel material 370 by filling the retaining plate 330 with the resin 340.

Japanese Patent Publication No. 3-30644 Japanese Patent No. 3492612

  However, in the conventional water stop structure as described in the above patent document, the PC steel material can be easily arranged in the water stop structure, and the water stop structure and the PC steel material are closely attached so that no gap is generated. I couldn't.

  If the water-stopping elastic body used in the water-stopping structure is to be brought into close contact with the PC steel material, the diameter of the insertion hole provided in the water-stopping elastic body is preferably small. However, if the diameter of the insertion hole provided in the waterstop elastic body is smaller than the outer diameter of the PC steel material, the PC steel material is inserted so that the small insertion hole is expanded when the PC steel material is inserted into the insertion hole. This will result in poor insertion.

  On the other hand, in order to improve the insertability of the PC steel material into the waterstop elastic body, it is conceivable to make the diameter of the insertion hole provided in the waterstop elastic body larger than the outer diameter of the PC steel material. However, when the diameter of the insertion hole is increased, the PC steel material can be inserted into the water-stopping elastic body. However, a gap is formed between the insertion hole and the PC steel material, and the adhesion between the two decreases. .

  In the configuration of Patent Document 1, the diameter of the insertion hole is made larger than the outer diameter of the PC steel material to ensure the insertion property, and the elastic body for water stop is compressed and deformed between the anchor head and the steel disk. The water-stopping property is improved. However, in the configuration of Patent Document 1, even if the elastic body is compressed and deformed, all the gaps originally existing between the outer diameter of the PC steel material and the insertion hole are filled, and the adhesion between the PC steel material and the elastic body is improved. There are cases where it cannot be secured.

  In the configuration of Patent Document 2, in order to compensate for the disadvantage caused by making the diameter of the insertion hole larger than the outer diameter of the PC steel material, in addition to using an elastic body in the water-stopping structure, water-stopping can be achieved by using a resin. Secured. However, in the configuration of Patent Document 2, the number of components is large, and workability is poor because an additional step such as filling a resin after arranging a plurality of components and compressing the elastic body is necessary. In addition, if the configuration of Patent Document 2 is applied to an anchor plate as in Patent Document 1, a resin filling hole is provided in the anchor plate or the anchor head separately from the grout injection part, or a resin filling part is provided in the anchor head itself. Must be formed. For these reasons, there is a problem that the anchor head must be formed into a complicated shape and the strength of the anchor head is lowered. Unlike the exit part of the bridge saddle, the anchor head is a member that directly supports the tension of the PC steel material. Therefore, it is practically impossible to have a configuration in which the strength is reduced as described above.

  Accordingly, a main object of the present invention is to provide a water-stopping elastic body that is easy to insert a PC steel material into the insertion hole of the elastic body and is excellent in water-stopping.

  Another object of the present invention is to provide a highly versatile water stop structure and a water stop method applicable to any structure using PC steel.

  The present invention achieves the above object by providing an elastic body with an insertion hole having a diameter smaller than the outer diameter of the PC steel material and a slit extending from the insertion hole to the outer periphery of the insertion hole.

  The elastic body for water stop according to the present invention is an elastic body for water stop that restricts movement of a fluid arranged around a strained PC steel material from one region in the longitudinal direction of the PC steel material to the other region. There is an insertion hole through which the PC steel material is inserted and a slit extending from the insertion hole to the outer periphery of the insertion hole, and the diameter of the insertion hole is equal to or less than the outer diameter of the PC steel material inserted into the insertion hole. It is characterized by.

  The elastic body for water stop according to the present invention can be applied not only to a fixing portion such as a ground anchor but also to an exit portion of a bridge saddle.

  Hereinafter, a water-stopping elastic body of the present invention will be described first, and then a water-stopping structure and a water-stopping method using the water-stopping elastic body will be described.

  The material of the elastic body may be any material as long as it can be deformed to the extent that the PC steel material can be inserted, and can strongly press the PC steel material in the inner diameter direction by the deformation of the elastic body. Examples thereof include natural rubber and ethylene propylene rubber. Typically, EPT-SEALER (registered trademark of Nitto Denko Corporation) can be suitably used.

  The shape of the elastic body is not limited, but a disk shape is preferable because it can be consistent with the cross-sectional shape of a pipe or steel pipe through which a PC steel material is inserted and arranged. In particular, if the elastic body is formed into a disk having a uniform thickness, the elastic body can be uniformly compressed and deformed as will be described later. Regardless of the shape, the elastic body presses the PC steel material inserted through the elastic body from the outer peripheral side so that no gap is formed between the elastic body and the PC steel material.

  The elastic body as described above is provided with at least one insertion hole for inserting the PC steel material and at least one slit extending outward from the insertion hole.

  The diameter of the insertion hole provided in the elastic body is set to be equal to or smaller than the outer diameter of the PC steel material. By making the diameter of the insertion hole smaller than the outer diameter of the PC steel material, when inserting the PC steel material into the insertion hole, the PC steel material can be configured to expand the insertion hole of the elastic body. The adhesiveness with the body is increased and the water stoppage is improved. Specifically, when the outer diameter of the PC steel material is D, the diameter of the insertion hole is preferably 0.2D or more and 1.0D or less. The outer diameter D of this PC steel is D when the PC steel is a bare PC steel, and the outer diameter of the resin coating layer is D when the PC steel is a resin-coated PC steel. In the case of an unbonded PC steel material having a sheath on the outer periphery of the steel material or resin-coated PC steel material, the outer diameter of the sheath is D. The diameter of the insertion hole is preferably not less than 0.5D and less than 1.0D, more preferably not less than 0.7D and not more than 0.8D in consideration of the insertion property and water-stopping property of the PC steel material. If the diameter of the insertion hole is less than 0.2D, it is difficult to insert the PC steel material into the insertion hole of the elastic body even if a slit described later is provided in the elastic body. If the diameter of the insertion hole is more than 1.0D, the elastic body presses the outer periphery of the PC steel material in the inner diameter direction, and sufficient adhesion between the PC steel material and the elastic body cannot be ensured.

  The slit may be formed so as to extend outward in the radial direction of the insertion hole to such an extent that the PC steel material can be easily inserted into the insertion hole of the elastic body. By providing a slit extending radially outward of the insertion hole from the insertion hole of the elastic body, the PC steel material can be easily inserted into the insertion hole even if the diameter of the insertion hole is smaller than the outer diameter of the PC steel material as described above. .

  The slit is formed to such an extent that the PC steel material can be easily inserted into the insertion hole, and that there is no gap in the slit due to deformation of the elastic body. Specifically, when the outer diameter of the PC steel material is D, the diameter of a circle passing through the outer end of the slit is preferably 1.0D or more and 3.0D or less. The diameter of the circle passing through the outer end of the slit is preferably more than 1.0D and not more than 2.0D, more preferably 1.2D to 1.5D, taking into consideration the insertion property of the PC steel material into the insertion hole and the waterstop property of the elastic body. is there. If the diameter of the circle passing through the outer edge of the slit is less than 1.0D, it becomes difficult to insert the PC steel material into the insertion hole of the elastic body. Further, if the diameter is more than 3.0D, it is difficult to ensure sufficient water stoppage.

  The shape of the slit is not particularly limited. The shape of the slit may be a notch or a notch, but if it is a notch, the faces facing each other across the notch will be in close contact, so PC steel is placed in the insertion hole When it is done, it is difficult to make a gap. In addition, the slits may extend radially from the insertion hole or may extend in the tangential direction of the insertion hole. However, if the slits extend radially, the opposing surfaces are easily deformed evenly across the slit. Easy to place PC steel in the insertion hole. It is preferable to form the slit into a linear cut extending radially from the insertion hole, because it is easy to insert the PC steel material into the insertion hole and it is difficult to form a gap between the slits.

  The number of slits may be singular or plural. In particular, when the plurality of slits are evenly arranged in the circumferential direction of the insertion hole, the insertion hole is uniformly deformed when the PC steel material is inserted into the insertion hole, so that the insertability of the PC steel material is improved. When the number of slits is 2 to 12, the insertion property of the PC steel material is good, and the water blocking property of the elastic body is good. Preferably, the number of slits is 4-8. If the number of slits is one, when the PC steel material is inserted into the insertion hole, the insertion hole is deformed into a strain and the water stoppage is lowered. If the insertion hole is more than 12, the strength of the elastic body will decrease and it will tear. Moreover, in the manufacturing process of the elastic body for water stop, an effort is required and cost becomes high.

  Such an elastic body can press the PC steel material more strongly from the outer peripheral side of the PC steel material by compressing and deforming between the first rigid body and the second rigid body as will be described later. Further, when the elastic body is compressed and deformed, the slit is also crushed, so that it becomes difficult to form a gap between the faces facing each other across the slit. By compressing the elastic body in this way, even if it is a low viscosity fluid such as cement milk, the fluid is restricted from moving from one region to the other region with the elastic body for water stop as a boundary. Can do.

  As a configuration for compressing the elastic body, for example, it is possible to tighten two rigid bodies sandwiching the elastic body in a direction approaching each other by a tightening mechanism. In the tightening mechanism, it is preferable that a through hole is formed in the two rigid bodies sandwiching the elastic body and the elastic body, and the tightening shaft is disposed so as to penetrate the elastic body and the two rigid bodies. When the fastening shaft is arranged, the elastic body can be compressed without protruding from the outer periphery of the elastic body or rigid body, so that other constituent members constituting the PC structure (for example, ground anchors) In the fixing portion, the arrangement of the anchor plate is not obstructed.

  The tightening shaft may be any shaft that can be driven in the direction of tightening at least one of the two rigid bodies that sandwich the elastic body. A typical example of the fastening shaft is a screw. When a screw is used for the tightening shaft, for example, a through hole is formed in two rigid bodies that sandwich the elastic body and the elastic body, and the screw is disposed so as to penetrate the elastic body and the two rigid bodies. Tighten as necessary. Of course, a screw hole may be formed in the rigid body, and the rigid body itself may be a member to be screwed.

  The water stop structure is formed using the elastic body for water stop as described above. Specifically, the water stop structure includes a first rigid body located on one region side, a second rigid body located on the other region side, a first rigid body, and a second rigid body. A water-stopping elastic body that is sandwiched between and compressed. The waterstop elastic body is compressed and deformed between the two rigid bodies by a tightening mechanism that fastens the first rigid body and the second rigid body. By such compression and deformation, the water stopping elastic body presses the PC steel material from the outer peripheral direction of the PC steel material. The slit provided in the elastic body is also crushed by the compression / deformation of the elastic body, and the gap in the vicinity of the insertion hole is almost eliminated, so that the movement of the fluid in the longitudinal direction of the PC steel material can be restricted. The water stop structure having such a configuration can regulate fluid movement in a structure using PC steel.

  Furthermore, it is preferable to have an outer periphery pressing portion that restricts the expansion of the water stopping elastic body in the outer peripheral direction when the water stopping elastic body is compressed and deformed. Such an outer periphery pressing portion may be provided on at least one of the first rigid body and the second rigid body, or may be a separate member from the rigid body. By providing the outer periphery pressing part, when the elastic body is compressed and deformed between the first rigid body and the second rigid body, the elastic body is prevented from being deformed so as to spread in the outer edge direction. Can do. That is, the stress due to compression applied to the elastic body is directed toward the inside of the elastic body, and the PC steel material can be pressed with a stronger force in the insertion hole of the elastic body.

  As described above, the water stop structure of the present invention as described above can be applied to a water stop structure in any structure using a tension material. For example, when the water stop structure of the present invention is applied to a fixing portion of a ground anchor as shown in FIG. 3, an anchor head 220 is used as the first rigid body, and a metallic disc 250 is used as the second rigid body. Is mentioned. Specifically, the metal disk 250, the elastic body for water stop according to the present invention, and the anchor head 220 are arranged in this order at the end of the PC steel material 270 arranged in the drilling hole, and the anchor head 220 is attached to the anchor plate 240. Abut. Next, after tensioning the PC steel 270 and fixing the PC steel 270 with the wedge 210, the screws 260 are passed through the screw holes provided in each component (anchor head 220, elastic body, metallic disc 250). Then, the elastic body is compressed and deformed by tightening. Due to this compression / deformation, the water stop elastic body presses the PC steel 270 in the inner diameter direction, so that the gap between the insertion hole of the water stop elastic body and the PC steel 270 can be substantially eliminated. Therefore, it is possible to restrict the fluid from moving in the longitudinal direction of the PC steel material 270 with the elastic body for water stop as a boundary. Finally, grout is filled in the hole 280 to ensure the fixing of the PC steel 270. A plurality of elastic bodies may be arranged, or one or more rigid bodies may be sandwiched between the anchor head 220 or the metal disc 250 and the elastic body, or the elastic bodies and the rigid bodies are alternately arranged. A rigid body may be disposed at both ends of the water stop structure.

  Further, when the water stop structure of the present invention is applied to the exit portion of a bridge saddle as shown in FIG. 4, for example, a plastic spacer 320 is used as a first rigid body, and a metal presser is used as a second rigid body. The use of a plate 350 is mentioned. By doing so, the elastic body is compressed and deformed between the spacer 320 and the presser plate 350, so that sufficient water stoppage can be secured in the waterstop elastic body. And the resin 340 can be omitted. Specifically, it is arranged at the outlet of the saddle, and the spacer 320 is engaged with the end of the steel pipe 310 that accommodates the PC steel 370, followed by the elastic body and the presser plate 350, and is elasticized by the tightening mechanism 360. Compresses and deforms the body. This compression / deformation causes the water-stopping elastic body and the PC steel 370 to be in close contact with each other, so that a gap between the insertion hole of the water-stopping elastic body and the PC steel 370 can be almost eliminated. According to such a water stop structure, it is possible to prevent the fluid from moving in the longitudinal direction of the PC steel 370 with the water stop elastic body as a boundary. Finally, grout is injected into the steel pipe to ensure the fixing of the PC steel. A plurality of rigid bodies and elastic bodies may be arranged like the water stop structure in the fixing unit described above.

  According to the elastic body for water stop of the present invention, since the diameter of the insertion hole of the elastic body is smaller than the outer diameter of the PC steel material, the PC steel material can be configured to push the insertion hole of the elastic body, so that the elastic body The PC steel material can be pressed in the inner diameter direction, and as a result, water stoppage can be improved. That is, the fluid can be restricted from moving in the longitudinal direction of the PC steel material with the elastic body for water stop of the present invention as a boundary.

  Further, according to the elastic body for water stop of the present invention, the slit is provided in the insertion hole of the elastic body, so that the PC steel material can be inserted even if the diameter of the insertion hole of the elastic body is smaller than the outer diameter of the PC steel material. Easy to insert through the hole.

  Furthermore, according to the water stop structure and the water stop method of the present invention, the elastic body can strongly press the PC steel material in the inner diameter direction by sandwiching and compressing and deforming the water stop elastic body between the two rigid bodies. . As a result, it is possible to reliably perform the water stop at the location where the water stop is required in the structure using the PC steel material.

<Example 1>
In the present embodiment, the water stop structure and the water stop method of the present invention in the fixing portion of the PC steel material that reinforces the girder portion of the bridge will be described with reference to FIG. 1 and FIG. The fixing unit is configured to have a water stop structure in its configuration.

[overall structure]
The anchoring part of PC steel provided inside the bridge girder is a structure for transmitting the tension of PC steel to the girder part of the bridge. As shown in FIG. 2, the PC steel materials 11 separated from each other by the spacer 17 (only one is shown in FIG. 2) are tensioned and gripped by the wedge 12. The tension force of the tensioned PC steel material 11 includes the wedge 12 that grips the PC steel material 11, the anchor disk 13 that has the fitting hole 13 THa into which the wedge 12 is fitted, the bearing pressure ring 14 that contacts the anchor disk 14, and the bearing ring 14. It is transmitted to the bridge girder via the bearing plate 18 that abuts. In this example, in addition to the above configuration, a water stop structure having a water stop elastic body 1, a first steel plate 15, and a second steel plate 16 is formed inside a cylindrical support ring 14. The fixing part.

  Specifically, the water stop structure in this example is elastic by the water stop elastic body 1, the first steel plate 15 and the second steel plate 16 arranged so as to sandwich the elastic body 1, and the steel plates 15 and 16. It is composed of a tightening mechanism (tightening screw 20b) for tightening the body 1. The elastic body 1 is compressed and deformed by being clamped by the steel plates 15 and 16, and presses the PC steel material 11 inserted through the insertion hole 2 of the elastic body 1 from the outer periphery. That is, in the insertion hole 2 of the elastic body 1, the elastic body 1 and the PC steel material 11 are in close contact with each other so that no gap is formed between them. The movement of fluid from one region to the other region is restricted.

[PC steel]
In this example, as the PC steel material 11, a strand in which seven strands were twisted to form a stranded wire and the outer periphery thereof was coated with epoxy was used.

[Elastic body for water stop]
As shown in FIG. 1, a water-stopping elastic body 1 is a disc-like one having a uniform thickness. The outer diameter of the elastic body 1 substantially matches the inner diameter of the support ring 14 described later. The material of the elastic body 1 was EPT-SEALER (registered trademark of Nitto Denko Corporation).

  As shown in FIG. 1, the elastic body 1 for water stop has an insertion hole 2 through which the strand described above can be inserted, and a slit 3 extending from the insertion hole 2 to the outer side in the radial direction of the insertion hole 2. Formed.

  In the elastic body 1, 56 insertion holes 2 were formed so that 56 PC steel materials could be inserted, and each insertion hole 2 was arranged at a symmetrical position with the center of the disk interposed therebetween. As described above, when the insertion holes are arranged so as to be symmetric with respect to the center of the disk, the deformation state of the elastic body 1 generated when the PC steel material is arranged in the insertion holes 2 is biased, and each insertion hole 2 It is possible to prevent a difference in force for fastening the PC steel material in the inner circumferential direction.

  The diameter of the insertion hole 2 was formed to be smaller than the outer diameter including the covering of the PC steel material inserted into the insertion hole 2. By doing so, the elastic body 1 presses the PC steel material from the outer periphery of the PC steel material toward the center of the PC steel material, so it is more resilient to the groove than is formed between each strand of the PC steel material. Body 1 is in close contact. Therefore, a gap is hardly generated between the PC steel material including the groove and the elastic body 1.

  The slit 3 was formed in a linear cut shape extending radially from the insertion hole 2 to the outside of the insertion hole 2. By forming the slits 3 radially, the surface of the elastic body opposed to the slit 3 when the PC steel material is inserted through the insertion hole 2 can be easily spread uniformly, so that the insertion property of the PC steel material is improved. In addition, since the slit 3 is formed in a straight cut shape, the surfaces of the elastic bodies facing each other across the slit 3 can be substantially adhered to each other, so that even after the PC steel material is inserted into the insertion hole 2, No gap is likely to occur in 3.

  The length of the slit 3 is formed so that the distance from the insertion hole 2 to the outer end of the slit 3 is the same in all the slits 3 and passes through the outer end of the slit 3 (FIG. 1 (C The diameter of () is larger than the outer diameter of the PC steel material to be inserted. If all the slits 3 have the same length, it is possible to suppress the stress generated when the elastic body 1 is deformed from being concentrated on one slit and the elastic body 1 from being torn. Further, since the distance from the center of the insertion hole 2 to the outer end of the slit 3 is larger than the outer diameter of the PC steel material, the PC steel material can be easily inserted into the elastic body 1.

  The number of slits 3 was six per one insertion hole 2, and the slits 3 were arranged so as to be evenly arranged in the circumferential direction. If the slits 3 are evenly arranged in the circumferential direction, when the PC steel material is inserted into the insertion hole 2, the elastic body 1 can be uniformly deformed from the insertion hole 2 in a concentric manner, thereby improving the insertion property of the PC steel material. be able to.

  Further, the water stopping elastic body 1 is provided with three through holes 4. One through hole 4 was provided at the center of the disk and two at positions near the edge of the disk and symmetrical with respect to the center of the disk. By providing the through-hole 4, as shown in FIG. 2, the two steel plates 15 and 16 arranged with the elastic body 1 sandwiched between them can be tightened to penetrate the tightening screw 20b for compressing the elastic body 1. . When the through-hole 4 is provided in the water stopping elastic body 1 and the tightening screw 20b is used for the tightening mechanism, the elastic body 1 can be tightened without protruding the tightening mechanism on the outer periphery of the elastic body 1. In addition, when the tightening screw 20 is used, the water stop structure and other members (in this example, the anchor disk 13) other than the members used for the water stop structure can be connected, so that each member can be easily positioned. Become.

[First steel plate and second steel plate]
The circular first steel plate 15 and the second steel plate 16 were formed of the same material so as to have the same outer diameter. The outer diameters of the steel plates 15 and 16 were formed slightly smaller than the inner diameter of the bearing ring 14 described later. By doing in this way, it is easy to arrange the steel plates 15 and 16 in the bearing ring 14. Further, as described above, since the outer diameter of the waterstop elastic body 1 is formed so as to substantially match the inner diameter of the bearing ring 14, the outer diameter of the steel plates 15 and 16 and the outer diameter of the waterstop elastic body 1 are The diameters are almost the same. Therefore, when the steel plates 15 and 16 are tightened, the waterstop elastic body 1 sandwiched between the steel plates 15 and 16 can be compressed over substantially the entire surface. Although not provided in this example, the steel plates 15 and 16 may be separately formed with an outer periphery pressing portion that covers the outer periphery of the waterstop elastic body 1 and restricts the expansion of the elastic body 1 in the outer peripheral direction. good.

  The steel plates 15 and 16 are provided with through holes 15THa and 16THa at positions corresponding to the insertion holes 2 provided in the water-stopping elastic body 1. Further, the steel plates 15 and 16 are provided with a screw screw through hole 15THb and a screw hole 16THb at positions corresponding to the through holes 4 of the elastic body 1, respectively. The second steel plate 16 moves in the direction of the anchor disk 13 by tightening the fastening screw 20b that is screwed into the screw hole 16THb of the second steel plate 16, and the second steel plate 16 is moved between the first steel plate 15 and the second steel plate 16. The water-stopping elastic body 1 sandwiched between the two can be compressed.

[Tightening mechanism]
In this example, the tightening screw 20b is used as the tightening mechanism. The fastening screw 20b is passed through an anchor disk 13, a first steel plate 15, and a through hole 13THb, 15THb, 4 of the water stop elastic body 1 to be described later, and screwed into a screw hole 16THb provided in the second steel plate 16. Combined. Further, since the second steel plate 16 has one screw hole 16THb at the center and two edges, the second steel plate 16 has a second screw screw 20b that is screwed into the screw hole 16THb at the center. The other fastening screw 20b prevents the steel plate 16 from rotating about the central fastening screw 20b. That is, the fastening screw 20b located at the center does not idle.

  In addition to the water stop structure constructed by combining the elastic body 1, the steel plates 15 and 16, and the tightening mechanism (clamping screw 20b) as described above, the fixing portion is formed by using the following configuration.

[Spacer]
The spacer 17 was formed in a disk shape and provided with a plurality of insertion holes 17THa at regular intervals. The spacer 17 is a member that separates the PC steel materials 11 at the fixing portion, and the PC steel materials 11 are spaced apart from each other by inserting the PC steel material 11 through the insertion holes 17THa provided in the spacer 17. be able to. The outer diameter of the spacer 17 was formed smaller than a through hole 18TH of a bearing plate 18 described later. The spacer 17 was provided with a tightening screw through hole 17THb at a position corresponding to the through hole 4 of the water stopping elastic body 1. The inner diameter of the through hole 17THb is formed larger than the outer diameter of the tightening screw 20b so that the protruding portion of the tightening screw 20b can escape inside.

[Wedge]
The wedge 12 was formed in a conical cylinder shape so that the PC steel material 11 could be placed inside the wedge. In addition, the wedge 12 was formed by joining three divided pieces having a circular cross section. By forming the wedge 12 into three divided pieces, the inner diameter can be changed within a predetermined range when the divided pieces are combined into a conical cylinder shape. Therefore, when the PC steel material 11 is arranged inside the wedge 12, the PC steel material 11 can be gripped by changing the inner diameter of the wedge 12 in the direction of shrinking. Of course, there may be two pieces or more than three pieces.

[Anchor disc]
The anchor disk 13 is formed in a disc shape and has a fitting hole 13THa into which the wedge 12 is fitted. The fitting hole 13THa includes a tapered portion matched to the shape of the wedge 12 and an insertion portion having a constant diameter continuously from the tapered portion, and also serves as an insertion hole through which the PC steel material 11 is inserted. The diameter of the insertion part is larger than the outer diameter of the PC steel material 11. Further, a plurality of grout passages 13io are formed in the anchor disk 13 so as to be interspersed between the fitting holes 13THa. The role of the grout passage 13io will be described later.

  The surface of the anchor disk 13 opposite to the surface into which the wedge 12 is fitted engages with a circular recess formed by a flange portion 14A of the pressure bearing ring 14 to be described later so that it can be aligned with the pressure bearing ring 14 The convex portion 13A is formed. Further, in the vicinity of the outer edge of the anchor disk 13, there is an engagement screw through hole 13THc through which an engagement screw 20c described later can be passed in the circumferential direction.

[Supporting ring]
The bearing ring 14 has a cylindrical shape with both ends opened. On one end face of the support ring 14, a flange portion 14A protruding in the inner circumferential direction is provided. The flange portion 14A can restrict the movement of the first steel plate 15 arranged in the bearing ring 14 in the direction of the anchor disk 13. That is, since the first steel plate 15 is held against the flange portion 14A, the elasticity sandwiched between the steel plates 15 and 16 when the second steel plate 16 moves in the direction of the anchor disk 13 by tightening the tightening screw 20b. The body 1 can be compressed.

  As described above, the inner diameter of the bearing ring 14 substantially coincides with the outer diameters of the first steel plate 15, the waterstop elastic body 1, and the second steel plate 16. By having such an inner diameter, the bearing ring 14 can be used as an outer periphery pressing portion that prevents the elastic body 1 for water stop from spreading in the outer diameter direction. The body 1 can be made to act in close contact with the PC steel material 11. That is, the water stopping elastic body 1 can strongly press the PC steel material 11 from the outer periphery of the PC steel material. Further, when the steel plates 15, 16 and the water stop elastic body 1 are arranged in the support ring 14, the end face of the second steel plate 16 on the spacer 17 side does not protrude from the support ring 14. The ring 14 is easily arranged on the bearing plate 18.

  Further, the bearing ring 14 is formed with a screw hole 14THc for an engagement screw at a position corresponding to the engagement screw through hole 13THc of the anchor disk 13 so that the engagement screw 20c can be penetrated. . In addition, a grout inlet 14i is formed in the flange portion 14A so that the grout can be filled from the outer peripheral side of the bearing ring 14 toward the recess formed by the flange portion 14A.

[Bearing plate]
The bearing plate 18 was formed in a rectangular plate shape. The bearing plate 18 has a through hole 18TH having a diameter larger than the outer diameter of the spacer 17. Further, an engagement screw screw hole 18Hc is provided in the vicinity of the through hole 18TH in the outer peripheral direction at a position corresponding to the screw hole 14THc of the support ring 14. An end of an engagement screw 20c for integrally engaging the anchor disk 13, the bearing ring 14, and the bearing plate 18 is screwed into the screw hole 18Hc. Accordingly, the tension of the PC steel material 11 is transmitted to the bridge girder body via the wedge 12, the anchor disk 13, the bearing ring 14 and the bearing plate 18.

[Water-stop structure at anchorage of PC structure]
In order to construct a water stop structure in the fixing portion, first, the bearing plate 18 was disposed so that the PC steel material 11 penetrates the through hole 18TH of the bearing plate 18. On the other hand, the dummy bolts were passed through the through holes 15THb · 4 of both members in the order of the first steel plate 15 and the waterstop elastic body 1, and screwed into the screw holes 16THb of the second steel plate 16. Next, the spacer engagement screw 20d is inserted into the spacer engagement screw insertion hole 17THd provided in the spacer 17, and the screw 20d is screwed into the screw hole 16Hd of the second steel plate 16, thereby the spacer 17 Is attached to the second steel plate 16, and the first steel plate 15, the elastic body for water stop 1, the second steel plate 16, and the spacer 17 are integrated. By doing so, the insertion hole 15THa of the first steel plate 15, the insertion hole 2 of the elastic body 1 for water stop, the insertion hole 16THa of the second steel plate 16, the insertion hole 17THa of the spacer 17 are arranged in a straight line. It becomes a long insertion hole. The PC steel material 11 was inserted into the continuous insertion hole, and the support ring 14 was arranged so as to cover the outer periphery of the first steel plate 15, the elastic body for water stop 1, and the second steel plate 16. At this time, the first steel plate 15 is abutted against the flange portion 14A of the bearing ring 14 and is restricted from moving in the direction of the flange portion 14A. Further, a packing 14P for a bearing ring is disposed between the flange portion 14A of the bearing ring 14 and the first steel plate 15, thereby improving the water stoppage of this portion. Then, the bearing ring 14 was attached to the bearing plate 18 with a hexagon socket head cap screw (which will be replaced later with the engagement screw 20c). When the bearing ring 14 is attached to the bearing plate 18, the spacer 17 is accommodated in the through hole 18TH.

  Next, the anchor disk 13 was arranged so that the convex part 13A of the anchor disk 13 was fitted into the concave part formed by the flange part 14A of the bearing ring 14. At this time, the PC steel material 11 was inserted into the fitting hole 13THa of the anchor disk 13. Then, the hexagon socket head cap screw arranged on the support ring 14 was replaced with the engagement screw 20c, and the support ring 14 and the bearing plate 18 were integrated from the anchor disk 13. After that, the dummy bolts that integrated the elastic body 1 and the steel plates 15 and 16 were replaced with the fastening screws 20b one by one. The tightening screw 20b was tightened to such an extent that the elastic body 1 was not compressed.

  Subsequently, the PC steel material 11 was tensioned and arranged so that the end of the PC steel material 11 was gripped by the wedge 12, and then the wedge 12 was fitted into the fitting hole 13THa of the anchor disk 13. The tension of the PC steel material 11 is transmitted from the wedge 12 to the spar portion of the bridge through the anchor disk 13, the bearing ring 14 and the bearing plate 19.

  After fixing the tension of the PC steel material 11 with the wedge 12, the tightening screw 20b was tightened. Since the screw head of the tightening screw 20b is held against the anchor disk 13 (see FIG. 2), when the tightening screw 20b is tightened, the second steel plate 16 moves in the direction of the anchor disk 13. On the other hand, since the movement of the first steel plate 15 is restricted by the flange portion 14A of the bearing ring 14, the waterstop elastic body 1 sandwiched between the two steel plates 15 and 16 is compressed and deformed. By this compression / deformation, the elastic body 1 can be pressed more strongly against the PC steel material 11 in the insertion hole 2 of the water stopping elastic body 1. At this time, since the waterstop elastic body 1 is in close contact with the PC steel material 11, the grout filled in the cap 19 described later is leaked to the steel plate 16 side with the waterstop elastic body 1 as a boundary. Can be suppressed.

  Finally, the cap 19 was attached to the end of the anchor disk 13 using a fastening screw 19S, and the inside of the fixing portion was filled with grout. Further, a cap packing 19P is disposed between the cap 19 and the anchor disk 13 so that the grout does not leak. The filling of the grout was performed by injecting the grout from the grout inlet 14i provided in the bearing ring 14. The injected grout is first filled between the bearing ring 14 and the anchor disk 13, and then filled into the cap 19 through a grout passage 13io provided in the anchor disk 13. The filling of the grout is finished when the grout fills the cap 19 and overflows from the grout outlet 19o.

  In addition, the elastic body for water stop according to the present invention can be easily applied not only to the water stop structure in the fixing portion inside the bridge girder but also to the ground anchor fixing portion shown in FIG. 3 and the exit portion of the bridge saddle shown in FIG. . Specifically, by replacing the water-stopping elastic body shown in each figure with the water-stopping elastic body of the present invention, it is easy to insert the PC steel material, and one region with the water-stopping elastic body as a boundary. Therefore, it is possible to provide a water stop structure that effectively suppresses the fluid from moving to the other region. In particular, in the exit portion of the bridge saddle as shown in FIG. 4, the fastening plate 330 can be omitted, so that the number of parts can be reduced and the labor for filling the fastening plate 330 with the resin 340 can be saved. be able to.

<Test example>
Next, using a water-stopping elastic body in which the diameter of the insertion hole, the number of slits, and the length of the slit were changed, a water-stopping structure simulated structure as shown in Example 1 was constructed, and this simulated structure The water-stopping property was tested. In the simulated structure, the PC steel is not tensioned or settled.

  The water-stopping elastic body used in this test example has a diameter of 0.1D, 0.5D, and 1.0D for the insertion hole for PC steel, the number of slits is 1, 2, 6, 12, and the outer edge of the slit An insertion hole with a diameter of 1.5D, 2.0D, and 3.0D was changed (D is the diameter). 36 insertion holes in which the above combinations were changed were provided in one elastic body, and it was examined whether or not the PC steel material used in Example 1 could actually be inserted through this elastic body. Further, after inserting the PC steel material, two steel plates were arranged so as to sandwich the elastic body, and the elastic body was compressed with a pressure corresponding to the pressure when the elastic body was tightened in Example 1 with the two steel plates. Of course, the expansion of the elastic body in the outer diameter direction was regulated so that the elastic body pressed the PC steel material more strongly in the inner circumferential direction. Then, the cement milk was filled in one area with the elastic body as a boundary, and it was visually confirmed from the other area with the elastic body as to whether the cement milk leaked from the PC steel material. . At this time, the pressure of the cement milk in the simulated structure was set assuming the pressure during actual construction.

  As a result of the test, the diameter of the insertion hole is 0.1D, and the diameter of the circle passing through the outer edge of the slit is 1.5D, the PC steel material is inserted compared to the diameter of the insertion hole of 0.5D / 1.0D. It took time to do. In addition, when the diameter of the insertion hole was 0.1D and the diameter of the circle passing through the outer edge of the slit was 2.0D / 3.0D, it was relatively easy to insert PC steel, but the slit was torn.

  In addition, when the number of slits is one, regardless of the diameter of the insertion hole and the diameter of the circle passing through the outer end of the slit, the elastic body around the insertion hole is deformed into strain when the PC steel material is inserted. Cement milk leaked from the part. When the number of slits is 2 or more, when the diameter of the insertion hole is 0.5D / 1.0D and the diameter of the circle passing through the outer edge of the slit is 1.5D / 2.0D / 3.0D, it is easy to insert Both were fine.

  The elastic body for water stop of this invention can be utilized suitably for the water stop structure and the water stop method in the structure using PC steel materials. In particular, the present invention can be suitably used for a water stop structure and a water stop method in a bridge girder, a fixing portion such as a bridge saddle exit and a ground anchor.

FIG. 1 (A) is a front view of the elastic body for water stop according to the present invention, FIG. 1 (B) is a cross-sectional view along the line AA ′ of the elastic body, and FIG. 1 (C) is an enlarged view of the insertion hole of the elastic body. The figure is shown. FIG. 2 is a partial cross-sectional view showing an outline of a water stop structure in a fixing part inside a bridge girder using the water stop elastic body of the present invention. FIG. 3 is a schematic view showing a water stop structure in a fixing portion of a conventional ground anchor. FIG. 4 is a schematic view showing a water stop structure at an exit portion of a conventional bridge saddle.

Explanation of symbols

1 Elastic body for water stop
2 Insertion hole 3 Slit 4 Through hole
11 PC steel 12 Wedge 13 Anchor disc
14 Bearing ring 15 First steel plate 16 Second steel plate
17 Spacer 18 Bearing plate
14A Flange part 13A Convex part 14P Packing for bearing ring
13THa Mating hole 15THa, 16THa, 17THa Through hole
13THb, 15THb, 17THb Tightening screw through hole 16THb Screw hole
13THc engagement screw through hole 14THc screw hole 18Hc screw hole
17THd Spacer engagement screw insertion hole 16Hd screw hole 18TH through hole
18TH spacer through hole
20b Clamping screw 20c Engagement screw 20d Spacer engagement screw
19 Cap 19S Retaining screw 19P Cap packing
14i Grout inlet 13io Grout passage 19o Grout outlet
200 Elastic body 210 Wedge 220 Anchor head
240 Anchor plate 250 Steel disc 260 Screw
270 PC steel 280 Drilling
300 Elastic body 310 Steel pipe 320 Spacer 330 Retaining plate 340 Resin
350 Presser plate 360 Screw 370 PC steel

Claims (3)

A water stop structure that regulates movement of a fluid disposed around a strained PC steel material from one region in the longitudinal direction of the PC steel material to the other region,
A first rigid body located on one region side;
A second rigid body located on the other region side;
A water-stopping elastic body sandwiched between the first rigid body and the second rigid body;
It said first rigid member, as well as through the second rigid member and the waterproof elastic body, a shaft tightening compressing the waterproof elastic body by tightening the two rigid bodies,
A member provided separately from the first rigid body and the second rigid body on the outer periphery of the waterstop elastic body, and expanding in the radial direction of the waterstop elastic body deformed by being compressed. The outer periphery presser part that regulates,
With
The elastic body for water stop is
An insertion hole having a diameter smaller than the outer diameter of the PC steel material to be inserted ;
A slit extending from the inserted hole to the outer periphery of the insertion hole,
A water stop structure characterized by comprising: The water stop structure according to claim 1, wherein the slit has a cut shape in which surfaces facing each other across the slit are in close contact. A water stopping method for restricting movement of a fluid arranged around a strained PC steel from one region in the longitudinal direction of the PC steel to the other region,
A step of preparing an insertion hole for inserting the PC steel material, an insertion hole having a diameter smaller than the outer diameter of the PC steel material, and a water-stopping elastic body having a slit extending from the insertion hole to the outer periphery of the insertion hole. When,
Providing a first rigid body and a second rigid body ;
A step of preparing an outer periphery pressing part separate from the two rigid bodies;
A step of placing the waterstop elastic body between the first rigid body and the second rigid body, and making these members penetrate the PC steel material;
The first rigid body, the second rigid body, and the water stopping elastic body are passed through a tightening shaft, and the outer periphery pressing portion restricts the spread of the water stopping elastic body in the radial direction while tightening. Compressing the elastic body for water stop between both rigid bodies by a shaft , and
A water stopping method characterized by restricting the movement of fluid from one region to the other region in the longitudinal direction of the PC steel material with the elastic body as a boundary.

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