JP4647523B2 - Manufacturing method of bi-directional pretension member - Google Patents

Description

  The present invention relates to a method of simultaneously manufacturing a plurality of bi-directional pretension members in series.

  In the bi-directional pretension member, a plurality of longitudinal PC steel materials extending in the longitudinal direction and a plurality of transverse PC steel materials extending in the transverse direction so as to intersect the longitudinal PC steel materials are arranged in the concrete member. It has been configured.

  FIG. 4 of “Patent Document 1” describes a method of simultaneously manufacturing a plurality of such two-way pretension members at a plurality of locations in the vertical direction.

  That is, in the manufacturing method described in FIG. 4 of “Patent Document 1”, the placement positions of the plurality of concrete members are arranged in series in the vertical direction, and the ground around the placement positions of the plurality of places is arranged. In a state where a plurality of reaction force devices are installed, a plurality of transverse PC steel materials are fixed to the reaction force devices located on both lateral sides of each placement position, and tension and release of these transverse PC steel materials using a jack By introducing a pre-stress in the transverse direction for each concrete member, and fixing a plurality of longitudinal PC steel materials to reaction force devices located at both longitudinal ends of the placement positions of a plurality of places, By using a jack to tension and release the longitudinal PC steel, longitudinal prestress is introduced into a plurality of concrete members.

JP 2005-47233 A

  In the manufacturing method described in the above-mentioned “Patent Document 1”, prestress is introduced in two directions in a state in which a plurality of reaction force devices are installed on the ground around a plurality of placement positions. Therefore, it is necessary to provide a structure with a long horizontal reaction force anchor as each reaction force device, and there is a problem that the manufacturing equipment becomes expensive. Moreover, in the method using such a reaction force device, there is a problem that it is difficult to manage the tension force of the PC steel material and it is not easy to introduce the desired prestress.

  In particular, when the ground at the site where the bi-directional pretension member is manufactured is a soft ground, there is a problem that it is difficult to fix and install the reaction force device itself.

  The present invention has been made in view of such circumstances, and in the case where a plurality of two-way pretension members are simultaneously manufactured in series, the desired prestress can be easily introduced with inexpensive manufacturing equipment. An object of the present invention is to provide a method for manufacturing a bi-directional pretensioning member.

  The present invention is intended to achieve the above object by introducing two-way prestress using a self-contained production bed.

That is, the manufacturing method of the bidirectional pretension member according to the present invention is as follows:
Bidirectional pretension in which a plurality of longitudinal PC steel materials extending in the longitudinal direction and a plurality of transverse PC steel materials extending in the transverse direction so as to intersect the longitudinal PC steel materials are disposed in the concrete member. In the method of simultaneously manufacturing a plurality of members at a plurality of locations in the vertical direction,
Using a vertically long production bed in which the vertical cross-sectional shape in the vertical direction and the horizontal direction are both substantially U-shaped,
A predetermined amount of the production bed is buried in the ground where the production bed is installed,
With one end of each lateral PC steel material fixed on one side wall of the production bed, the lateral PC steel material is tensioned and released using a jack installed on the other side wall of the production bed. By introducing lateral prestress to each concrete member placed between the both side walls,
With one end of each longitudinal PC steel material fixed to one end wall of the production bed, the tension of each longitudinal PC steel material using a jack installed on the other end wall of the production bed and By performing tension release, longitudinal prestress is collectively introduced into the plurality of concrete members placed between the both end walls.

  The specific number of the “plurality in the vertical direction” is not particularly limited.

  The specific arrangement and number of the “plural longitudinal PC steel materials” and the “plural transverse PC steel materials” are not particularly limited.

  The above-mentioned “production bed” is not particularly limited as long as the vertical cross-sectional shape in the vertical direction and the horizontal direction is a vertically long shape having a substantially U shape.

  As shown in the above configuration, in the method for producing a bi-directional pretension member according to the present invention, a bi-directional pre-tension member in which a plurality of longitudinal PC steel members and a plurality of transverse PC steel members are arranged in a concrete member. A plurality of tension members are manufactured at a plurality of locations in the vertical direction at the same time. At this time, a vertical production bed in which the vertical cross-sectional shape in the vertical direction and the horizontal direction is set to be substantially U-shaped is used. In the state where one end portion of each lateral PC steel material is fixed to one side wall of the production bed, the tension and the tension release of each lateral PC steel material are performed using a jack installed on the other side wall of the production bed. By introducing lateral pre-stress to each concrete member placed between the both side walls, each vertical wall on one end wall in the production bed With the one end of the PC steel fixed, by using a jack installed on the other end wall of the production bed, each longitudinal PC steel is tensioned and released, and placed between the end walls. Since the vertical prestress is collectively introduced to the plurality of concrete members, the following operational effects can be obtained.

  In other words, since the production bed itself uses a self-contained production bed that can receive the reaction force when the PC steel material is strained, the prestress is introduced in two directions. This eliminates the need for a reaction force device equipped with a horizontal reaction force anchor, which can reduce the cost of manufacturing equipment for bi-directional pretension members and facilitates the management of the tension of PC steel. It is possible to easily introduce the pre-stress of the period.

  As described above, according to the present invention, when a plurality of two-way pretension members are simultaneously manufactured in series, it is possible to easily introduce the desired prestress with an inexpensive manufacturing facility.

  Especially in the present invention, since it is designed to introduce two-way prestress using a self-contained production bed, even if the ground of the site for producing the two-way pretension member is soft ground, The bi-directional pretension member can be manufactured without any trouble. In this case, since the production bed is configured to have a certain width in the lateral direction for the production of the bi-directional pretension member, it can be easily arranged horizontally with respect to the installation ground.

  In the above configuration, if a box-shaped production bed in which both end walls and both side walls are continuously formed is used as the production bed, the wall thickness of each end wall and each side wall is reduced to some extent. However, it can receive the reaction force at the time of tension of PC steel.

  In the above configuration, if a predetermined amount of the production bed is embedded in the installation ground, it is possible to ensure that the production bed is elastically supported by the installation ground, thereby setting the production bed. It is possible to prevent an unnecessary bending moment from being generated in the production bed due to the state.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a view showing a production bed 10 used in a method for producing a bi-directional pretension member according to an embodiment of the present invention in a state in which a predetermined accessory device is mounted, and FIG. The top view and the same figure (b) are side sectional views.

  As shown in the figure, this production bed 10 is made of reinforced concrete and has an elongated rectangular outer shape in plan view, and its length in the longitudinal direction (long direction) is about 100 m. The horizontal length is set to a value of about 13 m. This production bed 10 is configured as a self-contained production bed, and is used in a state where it is installed on the flat ground 2. In the present embodiment, the ground 2 is a soft ground, and the production bed 10 is installed so as to sink into the ground 2 by a predetermined amount (specifically, about 0.8 m). .

  The production bed 10 has a bottom wall 10A, a pair of side walls 10B and 10C that rises upward at both lateral edges of the bottom wall 10A, and a vertical wall 1 that rises upward at both longitudinal edges of the bottom wall 10A. It consists of a pair of end walls 10D and 10E, and both vertical and horizontal vertical cross-sectional shapes thereof are set to be substantially U-shaped. At this time, the production bed 10 is configured as a box-shaped production bed in which both end walls 10D and 10E and both side walls 10B and 10C are continuously formed. A space is formed.

  The bi-directional pretension member 100 to be manufactured in the present embodiment includes 38 longitudinal PC steel members 102 extending in the longitudinal direction (19 pieces each in two upper and lower stages), and intersecting these longitudinal PC steel materials. Twenty-two horizontal PC steel members 104 extending in the horizontal direction are horizontally long concrete slabs arranged in the concrete member 106, and in 21 vertical positions in the working space of the production bed 10, 21 are manufactured at the same time.

  In the process of manufacturing the 21 bi-directional pretension members 100, lateral pre-stress and vertical pre-stress are introduced into each bi-directional pre-tension member 100. These two-way prestress introduction is performed as follows.

  In other words, with one end of each lateral PC steel material 104 fixed to one side wall 10B, each pair of jacks 50 installed on the other side wall 10C is used for tension of 22 lateral PC steel materials 104 and By releasing the tension, lateral prestress is introduced into each concrete member 106 placed between the side walls 10B and 10C.

  In addition, with one end wall 10D fixed to one end of each longitudinal PC steel material 102, 38 longitudinal PC steel materials are used by using a pair of jacks 30 installed on the other end wall 10E. By performing the tension 102 and releasing the tension, the vertical prestress is collectively introduced into the 21 concrete members 106 placed between the both end walls 10D and 10E. .

  2, 3, 4 and 5 are a detailed view of a portion II, a detailed view of a portion III, a detailed view of a portion IV and a detailed view of a portion V in FIG. 6 is a detailed sectional view taken along the line VI-VI in FIG.

  As shown in these drawings, the bottom wall 10A of the production bed 10 has a wall thickness set to a value of about 1.2 m, and the bottom surface of the bottom wall 10A is formed in a flat shape over the entire area. Has been.

  Each side wall 10B, 10C of the production bed 10 has a wall thickness set to a value of about 1.2 m, and its height is set to a value of about 2.2 m from the lower surface of the bottom wall 10A. ing. On the inner side surfaces of these side walls 10B and 10C, haunch portions 10Ba and 10Ca having an inclination angle of about 45 ° are formed at the lower end portions thereof.

  Further, the wall thickness of each end wall 10D, 10E of the production bed 10 is set to a value of about 2.2 m at the upper end surface of the end wall 10D, 10E, and the height is set to each side wall. The height is set to the same value as 10B and 10C. The inner side surfaces of the end walls 10D and 10E are formed as inclined surfaces 10Da and 10Ea having an inclination angle of about 45 °.

  At that time, one end wall 10D has 38 insertion holes (not shown) for inserting 38 longitudinal PC steel members 102 in a two-stage arrangement with a predetermined interval in the horizontal direction. It is formed so as to penetrate in the vertical direction.

  A pretension introduction device 20 is attached to the other end wall 10E. The pretension introduction device 20 includes a fixing block 22 disposed in the vicinity of the inner side of the end wall 10E, a receiving beam 24 disposed in the vicinity of the outer side of the end wall 10E, the fixing block 22, and the end wall. 10E and the receiving beam 24 are vertically arranged in two stages so as to vertically penetrate the fixing block 22 and the receiving beam 24, and two pairs of tension rods 26 fixed to the receiving beam 24 by nuts 28, and end portions The configuration includes a pair of jacks 30 installed between the wall 10 </ b> E and the receiving beam 24. At that time, the fixing block 22 has 38 insertion holes (not shown) for inserting the 38 longitudinal PC steel materials 102 in the vertical direction with a predetermined interval in the horizontal direction and arranged in two vertical stages. It is formed so as to penetrate through.

  Similarly, on one side wall 10B, 22 insertion holes (not shown) for inserting the 22 transverse PC steel members 104 at predetermined positions in the longitudinal direction are provided at positions corresponding to the 21 locations. It is formed so as to penetrate in the lateral direction at intervals.

  Further, the pre-tension introduction devices 40 are attached to the other side wall 10C at 21 locations at equal intervals in the vertical direction. The pretension introduction device 40 includes a fixing block 42 disposed near the inside of the side wall 10C, a receiving beam 44 disposed near the outside of the side wall 10C, and the fixing block 42, the side wall 10C, and the receiving beam 44. It was arranged so as to penetrate in the lateral direction, and both ends were installed between two pairs of tension rods 46 fixed to the fixing block 42 and the receiving beam 44 with nuts 48, and the side wall 10C and the receiving beam 44. The configuration includes a pair of jacks 50. At that time, each fixing block 42 has 22 insertion holes (not shown) through which the 22 horizontal PC steel materials 104 are inserted so as to penetrate in the horizontal direction at predetermined intervals in the vertical direction. Is formed.

  Next, the manufacturing process of the two-way pretension member 100 will be described.

  First, a formwork (not shown) corresponding to the shape of the concrete member 106 is installed at 21 locations in the vertically long work space in the production bed 10, and 38 vertical PC steel materials 102 are horizontally arranged in two steps. Are arranged at equal intervals, and at each location, the twenty-two horizontal PC steel materials 104 are arranged at equal intervals in the vertical direction in the vicinity of the upper portion of the vertical PC steel material 102 located in the upper stage.

  Each longitudinal PC steel material 102 is fixed by the fixing tool 32 on the outer surface of the end wall 10D in a state where one end thereof is inserted into an insertion hole formed in one end wall 10D, and the other end. In the state where the portion is inserted through the insertion hole formed in the fixing block 22, fixing is performed by the fixing tool 32 on the end surface on the outer side in the vertical direction of the fixing block 22. Then, the receiving beam 24 is moved outward in the vertical direction by a pair of jacks 30 installed between the other end wall 10E and the receiving beam 24, and accordingly, the fixing block is connected via the tension rod 26. 22 is moved to the outer side in the vertical direction, whereby 38 vertical PC steel materials 102 are collectively tensioned.

  On the other hand, each lateral PC steel material 104 is fixed by the fixing tool 52 on the outer surface of the side wall 10B in a state where one end thereof is inserted into the insertion hole formed in the one side wall 10B, and the other end is fixed. Then, in the state of being inserted through the insertion hole formed in the fixing block 42, fixing is performed by the fixing tool 52 on the outer end surface in the lateral direction of the fixing block 42. Then, the receiving beam 44 is moved laterally outward by a pair of jacks 50 installed between the other side wall 10 </ b> C and the receiving beam 44, and accordingly, the fixing block 42 is moved via the tension rod 46. It moves to the outside in the lateral direction, thereby tensioning the 22 lateral PC steel members 104 for each bi-directional pretensioning member 100 together. This operation is performed individually for each of the 21 pretension introduction devices 40.

  Next, concrete is placed in the molds installed in each of the 21 locations and cured for a predetermined time.

  Thereafter, in each pretension introduction device 40, the tension of the 22 transverse PC steel members 104 by the pair of jacks 50 is released at once. At this time, in order to minimize the displacement of each bi-directional pretensioning member 100 due to the tension release, the tension release is performed little by little for each pretension introduction device 40 in order. After this tension release is completed, the pretension introduction device 20 releases the tension of the 38 longitudinal PC steel members 102 by the pair of jacks 30 at once.

  Finally, after cutting off the protruding portion from each mold in each longitudinal PC steel material 102 and each transverse PC steel material 104, the two-way pretension member 100 is taken out from each of these molds.

  As described above in detail, in the present embodiment, the two-way pretension member 100 in which the 38 longitudinal PC steel members 102 and the 22 transverse PC steel members 104 are arranged in the concrete member 106 is used as a longitudinal member. 21 pieces are manufactured at the same time at 21 locations in the direction. At this time, a vertical production bed 10 in which the vertical cross-sectional shapes in the vertical direction and the horizontal direction are both substantially U-shaped is used. 10, with one end of each lateral PC steel material 104 fixed to one side wall 10 </ b> B in 10, tension and release of tension in each lateral PC steel material 104 using a jack 50 installed on the other side wall 10 </ b> C in the production bed 10. As a result, lateral prestress is introduced into each concrete member 106 placed between the side walls 10B and 10C. In the state where one end portion of each longitudinal PC steel material 102 is fixed to one end wall 10D of the production bed 10, each longitudinal PC steel material is used by using the jack 30 installed on the other end wall 10E of the production bed 10. By performing the tension of 102 and releasing the tension, the prestress in the vertical direction is collectively introduced to the 21 concrete members 106 placed between the both end walls 10D and 10E. The following effects can be obtained.

  That is, since the prestress is introduced in two directions using the self-contained production bed 10, a reaction device having a long horizontal reaction force anchor as in the prior art becomes unnecessary, and therefore The cost of manufacturing equipment for the two-way pretension member 100 can be reduced, and the tension force of each longitudinal PC steel material 102 and each transverse PC steel material 104 can be easily managed. Can be easily performed.

  As described above, according to the present embodiment, when a plurality of two-way pretension members 100 are simultaneously manufactured in series, it is possible to easily introduce the desired prestress with an inexpensive manufacturing facility.

  In particular, in this embodiment, since the self-reducing production bed 10 is used to introduce two-way prestress, the ground 2 at the site where the two-way pretension member 100 is manufactured is a soft ground. Nevertheless, the bi-directional pretension member 100 can be manufactured without any trouble. At this time, since the production bed 10 is configured to have a certain width in the lateral direction for the production of the bi-directional pretension member 100, it can be easily arranged horizontally with respect to the ground 2. Become.

  In the present embodiment, a box-shaped production bed in which both end walls 10D and 10E and both side walls 10B and 10C are continuously formed is used as the production bed 10. Despite the fact that the wall thicknesses of the section walls 10D and 10E and the side walls 10B and 10C are relatively thin, the reaction force is exerted when the longitudinal PC steel members 102 and the transverse PC steel members 104 are tensioned. Can be.

  Furthermore, in this embodiment, the production bed 10 is used in a state of a semi-underground bed embedded in a predetermined amount with respect to the ground 2, so that the production bed 10 is reliably elastically supported by the ground 2. Can be. Thus, it is possible to prevent an unnecessary bending moment from being generated in the production bed 10 due to the installation state of the production bed 10.

  By the way, in the said embodiment, although the production bed made from a reinforced concrete was used as the production bed 10, you may make it use the production bed made from a reinforced concrete suitably reinforced with PC steel materials.

  Moreover, in the said embodiment, although the two-way pretension member 100 used as the manufacture object was demonstrated as what is a horizontally long concrete slab, even when it is a member which has a shape other than this, the said embodiment By adopting this manufacturing method, it is possible to obtain the same effects as in the case of the above embodiment.

  In addition, the numerical value shown as a specification in the said embodiment is only an example, and of course, you may set these to a different value suitably.

It is a figure which shows the production bed used for the manufacturing method of the bidirectional | two-way pretension member which concerns on one Embodiment of this invention in the state with which the predetermined | prescribed attachment apparatus was mounted | worn, Comprising: The figure (a) is a top view, the figure (B) is a sectional side view Detailed view of part II in Fig. 1 Detailed view of part III in Fig. 1 Detail view of section IV in Fig. 1 Detailed view of part V in FIG. Detailed cross-sectional view taken along line VI-VI in Fig. 1

Explanation of symbols

2 Ground 10 Production bed 10A Bottom wall 10B, 10C Side wall 10Ba, 10Ca Hunch part 10D, 10E End wall 10Da, 10Ea Inclined surface 20, 40 Pretension introduction device 22, 42 Fixing block 24, 44 Receiving beam 26, 46 Tension Rod 28, 48 Nut 30, 50 Jack 32, 52 Fixing tool 100 Bidirectional pre-tension member 102 Longitudinal PC steel 104 Transverse PC steel 106 Concrete member

Claims (2)

Bidirectional pretension in which a plurality of longitudinal PC steel materials extending in the longitudinal direction and a plurality of transverse PC steel materials extending in the transverse direction so as to intersect the longitudinal PC steel materials are disposed in the concrete member. In the method of simultaneously manufacturing a plurality of members at a plurality of locations in the vertical direction,
Using a vertically long production bed in which the vertical cross-sectional shape in the vertical direction and the horizontal direction are both substantially U-shaped,
A predetermined amount of the production bed is buried in the ground where the production bed is installed,
With one end of each lateral PC steel material fixed on one side wall of the production bed, the lateral PC steel material is tensioned and released using a jack installed on the other side wall of the production bed. By introducing lateral prestress to each concrete member placed between the both side walls,
With one end of each longitudinal PC steel material fixed to one end wall of the production bed, the tension of each longitudinal PC steel material using a jack installed on the other end wall of the production bed and A method for producing a two-way pretension member, wherein longitudinal prestress is collectively introduced into a plurality of concrete members placed between both end walls by releasing tension.   2. The method for producing a bi-directional pretension member according to claim 1, wherein a box-shaped production bed in which the both end walls and both side walls are continuously formed is used as the production bed.

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