JP2014020137A - Precast floor slab and erection method of precast floor slab - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a precast floor slab and an erection method of the precast floor slab in which a height adjustment of the precast floor slab is not required in a portion at an upper side of all main girders in the precast floor slab.SOLUTION: An erection method of a precast floor slab includes: a first step of providing three or more main girders 2 side by side in a bridge width direction Y of a bridge 9 and installing a temporary rail 3 on a top face of an upper part 21a of an intermediate main girder 21 provided in the middle in the bridge width direction Y; the second step of installing a precast floor slab 1 in the upper part 2a of the main girder 2, the precast floor slab 1 being provided with bolt holes 12 in both end portions 11a at an upper side of both end main girders 22 provided in both ends in the bridge width direction Y and being provided with no bolt hole 12 in an intermediate portion 11b at an upper side of the intermediate main girder 21; and a third step of projecting a distal end portion 14a of a height adjusting bolt 14 mounted into the bolt holes 12 provided in both the end portions 11a from a bottom face 1b of the precast floor slab 1 so as to abut the distal end portion 14a to the top face of the upper parts 22a of both the end main girders 22, thereby adjusting a height of the precast floor slab 1.

Description

  The present invention relates to a precast floor slab installed as a bridge superstructure with respect to a main girder provided on a bridge pier as a bridge substructure and a method of laying the precast floor slab.

  Conventionally, for the purpose of constructing a bridge, a precast slab and a precast slab erection method as disclosed in Patent Document 1 have been proposed.

  The precast floor slab disclosed in Patent Document 1 has two main girders arranged in the bridge width direction, and a box opening portion penetrating the precast floor slab in the vertical direction at a position above all the main girders in the precast floor slab Is provided.

  In addition, in the precast floor slab erection method disclosed in Patent Document 1, in the portion that is above all the main girders in the precast floor slab, the gibber is attached to all the boxed portions provided in the precast floor slab, In these dowels, shear resistance is applied to limit the horizontal movement of the precast floor slabs. This adjusts the height of the precast slabs installed on the floor.

JP 2002-356814 A

  However, the precast floor slab erection method disclosed in Patent Document 1 is provided with a box-opening portion at a position above all main girders in the pre-cast floor slab, and precast using a gibber in all box-opening portions. By moving the floor slab in the vertical direction, it is necessary to adjust the height of the precast floor slab installed on the upper part of the main girder, and there is a problem that the labor required for the construction of the precast floor slab increases.

  Furthermore, in the precast floor slab erection method disclosed in Patent Document 1, after the precast floor slab is installed on the upper part of the main girder, the boxed portion of the precast floor slab is filled and solidified. For this reason, in the precast floor slab disclosed in Patent Document 1, the mortar peels off from the precast floor slab due to aging at the box opening portion, and a water channel is formed at the interface between the precast floor slab and the mortar. There was a problem that the upper part of the main girder made of steel might corrode due to rainwater or the like that passed therethrough, and the upper part of all the main girders might be deteriorated.

  Therefore, the present invention has been devised in view of the above-mentioned problems, and the object of the present invention is to adjust the height of the precast slab at a position above all main girders in the precast slab. It is an object of the present invention to provide a precast floor slab that does not require a slab and a method for laying the precast floor slab.

  The precast slab erection method according to the first invention is a precast slab erection method in which three or more main girders are provided side by side in the bridge width direction of the bridge, and the precast slab is installed in the bridge width direction. Among the three or more main girders, the first step of installing a temporary fence on the upper surface of the intermediate main girder provided in the middle of the bridge width direction, and the three or more main girders provided at both ends of the bridge width direction A precast floor slab in which a bolt hole penetrating in the vertical direction is provided in a portion above the main girder at both ends and the bolt hole is not provided in a portion above the intermediate main girder is attached to the main girder. By projecting the tip of the height adjusting bolt attached to the bolt hole provided in the second step to be installed on the upper portion and the upper part of the both ends main girders from the lower surface of the precast floor slab, Contact the upper surface of the main girder at both ends. By, characterized in that it comprises a third step of adjusting the height of the precast slab.

  The precast floor slab erection method according to the second invention is the first invention according to the first invention, wherein in the first step, among the three or more steel main girders arranged side by side in the bridge width direction, provided in the middle of the bridge width direction. In addition to installing a rubber temporary tack on the upper surface of the intermediate main girder, in the third step, with respect to the height adjusting bracket embedded in the bolt hole provided in the portion above the both end main girder The height adjusting bolt attached by screwing from above is rotated by the bolt hole, and the tip of the height adjusting bolt protrudes from the lower surface of the precast floor slab. The height of the precast slab is adjusted by bringing it into contact with the upper surface of the beam.

  The precast slab according to the third aspect of the invention is a precast slab laid on top of three or more main girders arranged side by side in the bridge width direction of the bridge. Bolt holes penetrating in the vertical direction are provided in the upper part of both ends of the main girder provided at both ends in the bridge width direction, and installed on the upper surface of the intermediate main girder provided in the middle of the bridge width direction. The bolt hole is not provided in a portion above the temporary tack.

  According to the first and second inventions, the height adjusting bolt is moved up and down only in the bolt holes provided at both end portions of the precast floor slab, and the height of the precast floor slab at the intermediate portion is not required to be adjusted. It will be a thing. For this reason, according to 1st invention, 2nd invention, the location which rotates a height adjustment volt | bolt using a large-sized impact wrench etc. can be decreased, and the effort required for construction of a precast floor slab can be reduced. Is possible. Further, according to the first and second inventions, it is possible to avoid the deterioration of the upper parts of all the steel main girders due to rain water or the like.

  Further, according to the first and second inventions, it is possible to reduce the number of places where the tip ends of the height adjusting bolts are rotated on the upper surfaces of the upper portions of the plurality of main girders, thereby reducing damage to the upper portions of the main girders. It becomes possible. Furthermore, according to the first and second inventions, it is possible to avoid interference between the bolts of the attachment plate and the tip of the height adjusting bolt, and it is easy to install the precast floor slab on the main girder. It becomes possible to.

  Further, according to the third invention, it is possible to provide a precast floor slab that implements the precast floor slab erection method according to the first and second inventions, and only at both end portions of the precast floor slab. Since bolt holes are provided and bolt holes are not provided in the intermediate part, the number of places where the bolt holes are provided can be reduced, so that the cross-sectional defect of the precast floor slab can be reduced. It is possible to improve the strength of the plate.

It is a perspective view which shows the bridge in which the precast slab concerning this invention was installed. It is a side view which shows the 2nd process of the construction method of the precast floor slab which concerns on this invention. It is a perspective view which shows the 1st process of the construction method of the precast floor slab which concerns on this invention. (A) is a side view which shows the precast floor slab which concerns on this invention, (b) is an expanded side sectional view which shows the bolt hole of the precast floor slab which concerns on this invention. (A) is a side view showing a third step of the precast floor slab erection method according to the present invention, and (b) is a bolt hole showing the third step of the precast slab erection method according to the present invention. It is an expanded side sectional view. It is an expanded side sectional view which shows the aspect which filled the hole of the concrete floor slab with mortar and solidified.

  Hereinafter, the form for implementing the precast slab to which this invention is applied is demonstrated in detail, referring drawings.

  As shown in FIG. 1, the precast floor slab 1 to which the present invention is applied is to construct a superstructure of the bridge 9 by arranging a plurality of precast floor slabs 1 in a row in the bridge axis direction X. The precast floor slab 1 to which the present invention is applied includes an upper portion 2a of a plurality of main girders 2 arranged in the bridge width direction Y on a head portion 91a of a bridge pier 91 erected on a ground 9a on which a bridge 9 is provided. Installed.

  As shown in FIG. 2, the plurality of main girders 2 include an intermediate main girder 21 provided in the middle of the bridge width direction Y among the plural main girders 2 arranged side by side in the bridge width direction Y, and the bridge width direction. Both end main girders 22 provided at both ends of Y are provided. In the example shown in the figure, the plurality of main girders 2 are provided side by side in the bridge width direction Y. However, the present invention is not limited to this, and any quantity of three or more in the bridge width direction Y may be provided side by side. .

  The plurality of main girders 2 are made of H-section steel having a web provided so as to extend in the vertical direction and flanges provided at the upper and lower ends of the web. The plurality of main girders 2 are not limited to this, and any material and shape can be used as long as the precast floor slab 1 can be installed on the upper part 21a of the intermediate main girder 21 and the upper part 22a of the both-end main girder 22. May be used.

  As shown in FIG. 3, the intermediate main girder 21 is provided with the temporary tack 3 on the upper surface of the upper portion 21 a of the intermediate main girder 21. On the other hand, the double-sided main girder 22 can be configured not to install the temporary lock 3 on the upper surface of the upper part 22a of the double-sided main girder 22.

  The intermediate main girder 21 is provided with two temporary guards 3 on the upper surface of the upper part 21a of each intermediate main girder 21. However, the present invention is not limited to this, and any number of temporary guards 3 are installed. May be. For example, when four or more intermediate main girders 21 are arranged in the bridge width direction Y and the main girder 2 is provided, a temporary fence 3 is installed on the upper surface of the upper portion 21a of the intermediate main girder 21 in some intermediate main girders 21. You can also not.

  The temporary tack 3 is mainly made of rubber having a rectangular parallelepiped shape having a width of 100 mm, a depth of 150 mm, and a height of 30 mm to 100 mm, but is not limited thereto, and can support the precast floor slab 1. Any material and shape may be used.

  As shown in FIG. 4A, the precast floor slab 1 to which the present invention is applied is a flat precast concrete having an upper surface 1a and a lower surface 1b. The precast floor slab 1 to which the present invention is applied is a bolt hole 12 used for height adjustment of the precast floor slab 1 at both end portions 11a that are above the both end main girders 22 when installed on the upper part 2a of the main girder 2. Is provided. At the same time, the precast floor slab 1 to which the present invention is applied is not provided with the bolt hole 12 used for adjusting the height of the precast floor slab 1 at the intermediate portion 11b above the intermediate main beam 21.

  As shown in FIG. 4B, the bolt hole 12 is provided by penetrating the precast floor slab 1 in the vertical direction so as to communicate the upper surface 1 a and the lower surface 1 b of the precast floor slab 1. The bolt hole 12 can further embed a height adjusting fitting 13 inside the precast floor slab 1.

  The height adjustment fitting 13 is a cylindrical fitting penetrated in the vertical direction, and has an outer peripheral portion 13a having a circular cross section and an inner peripheral portion 13b having a circular cross section and threaded. The height adjusting fitting 13 has a cylindrical portion having a circular cross section and a tapered portion having a reduced diameter from the top to the bottom in the outer peripheral portion 13a, and the outer peripheral portion 13a is a precast floor slab. It is embedded in the concrete of 1 and attached. The height adjusting bracket 13 is attached by screwing the height adjusting bolt 14 from above the precast floor slab 1 in the inner peripheral portion 13b that is threaded.

  In the precast floor slab 1 to which the present invention is applied, the bolt hole 12 is not provided in the intermediate portion 11b above the intermediate main girder 21, and therefore the bolt hole 12 is also provided in the intermediate portion 11b. In comparison, the cross-sectional defect of the precast floor slab 1 can be reduced, and the strength of the precast floor slab 1 can be improved.

  Next, a method for installing a precast slab to which the present invention is applied will be described in detail with reference to the drawings.

  As shown in FIG. 3, the precast floor slab 1, to which the present invention is applied, includes a plurality of main girders 2 arranged in the bridge width direction Y on the head 91 a of the pier 91 in the first step. Two temporary fences 3 are installed on the upper surface of the upper portion 21a of each intermediate main girder 21 provided in the middle of the bridge width direction Y.

  Next, as shown in FIG. 2, the precast floor slab 1 to which the present invention is applied includes a plurality of main girders 2 arranged side by side in the bridge width direction Y on the head 91a of the pier 91 in the second step. The precast floor slab 1 is installed on the upper part 2a of.

  At this time, the precast floor slab 1 comes into contact with the upper surface of the temporary anchor 3 installed in the first step and the lower surface 1b of the intermediate portion 11b of the precast floor slab 1, and is supported by the temporary anchor 3. become. Further, the temporary tack 3 is made of an elastic body such as rubber, so that when the precast floor slab 1 is installed in the second step, it can serve as a cushioning material.

  Furthermore, as shown in FIG. 5 (a), the method for laying the precast floor slab 1 to which the present invention is applied is shown in FIG. 5 (a), in the third step, at both end portions 11a of the precast floor slab 1 above the both end main girders 22, The tip end portion 14 a of the height adjusting bolt 14 attached to the hole 12 is projected from the lower surface 1 b of the precast floor slab 1.

  At this time, as shown in FIG. 5 (b), the precast floor slab 1 to which the present invention is applied is installed by being screwed into the inner peripheral portion 13b of the height adjusting fitting 13 attached to the inside of the concrete. The height adjusting bolt 14 can be moved up and down by rotating the height adjusting bolt 14 in the bolt hole 12 from above using a large impact wrench or the like.

  In the construction method of the precast floor slab 1 to which the present invention is applied, the tip end portion 14 a of the height adjusting bolt 14 is brought into contact with the upper surface of the upper portion 22 a of the both ends main girder 22, and the height adjusting bolt 14 is rotated in the bolt hole 12. By doing so, the height adjusting bolt 14 receives a reaction force from the upper surface of the upper part 22a of the both ends main girder 22, and the height of the precast floor slab 1 is adjusted.

  At this time, the temporary anchor 3 is made of an elastic body such as rubber, and is compressed by receiving the weight of the precast floor slab 1 from the lower surface 1b of the intermediate portion 11b of the precast floor slab 1 installed in the second step. It is in the state. For this reason, even if the temporary anchor 3 is a case where the height of the precast floor slab 1 is adjusted in the third step and the precast floor slab 1 moves upward by a predetermined distance, the temporary anchor 3 installed in the first step is used. It is possible to prevent the temporary tack 3 from being detached while maintaining the state in which the upper face of the cage 3 is in contact with the lower face 1b of the intermediate portion 11b of the precast slab 1 installed in the second step.

  The method of laying the precast floor slab 1 to which the present invention is applied is such that the height adjusting bolts 14 are moved up and down only in the bolt holes 12 provided at both end portions 11a of the precast floor slab 1 and the precast floor slab 1 at the intermediate portion 11b. It does not require adjustment of the height.

  For this reason, the construction method of the precast floor slab 1 to which the present invention is applied can reduce the number of places where the height adjusting bolt 14 is rotated using a large impact wrench or the like, and all the parts of the precast floor slab 1 Compared with the case where the height of the precast floor slab 1 is adjusted, it becomes possible to reduce the labor required for the construction of the precast floor slab 1.

  Moreover, the construction method of the precast slab 1 to which the present invention is applied can reduce the number of places where the tip end portion 14a of the height adjusting bolt 14 is rotated on the upper surface of the upper portion 2a of the plurality of main girders 2, and the bridge width. Compared with the case where the height of the precast floor slab 1 is adjusted with all the main girders 2 arranged side by side in the direction Y, damage to the upper part 2a of the main girder 2 can be reduced.

  Here, as shown in FIG. 3, the main girder 2 provided continuously in the bridge axis direction X of the bridge 9 is provided with an attachment plate 23 on the upper part 2a of the adjacent main girder 2, and bolts 23a are provided in the vertical direction. It is common to use and fasten. At this time, the construction method of the precast floor slab 1 to which the present invention is applied can reduce the number of places where the tip end portions 14a of the height adjusting bolts 14 are rotated on the upper surfaces of the upper portions 2a of the plurality of main girders 2. Interference between the bolt 23a of the plate 23 and the tip 14a of the height adjusting bolt 14 can be avoided. For this reason, the construction method of the precast floor slab 1 to which the present invention is applied is compared with the case where the height of the precast floor slab 1 is adjusted by all the main girders 2 arranged side by side in the bridge width direction Y. It is possible to easily install the plate 1 on the upper part 2a of the main beam 2.

  In general, in the construction of the concrete floor slab 100, as shown in FIG. 6, after adjusting the height of the concrete floor slab 100, the hole 101 provided in the concrete floor slab 100 is filled with mortar 102. Consolidated. Accordingly, the mortar 102 is peeled off from the concrete floor slab 100 with the passage of time, and a water channel 100b is formed at the interface 100a between the concrete floor slab 100 and the mortar 102. At this time, rainwater or the like passing through the water channel 100b, etc. The upper part 2a of the steel main girder 2 may be corroded.

  The method of laying the precast floor slab 1 to which the present invention is applied is that the bolt hole 12 is provided only at both end portions 11a of the precast floor slab 1 and the bolt hole 12 is not provided at the intermediate portion 11b. Since the deterioration of the upper part 21a of the girder 21 can be avoided and the number of places where the bolt holes 12 are provided can be reduced, the upper part 2a of all the steel main girders 2 is deteriorated by rainwater or the like. It can be avoided.

  As mentioned above, although the example of embodiment of this invention was demonstrated in detail, all the embodiment mentioned above showed only the example of actualization in implementing this invention, These are the technical aspects of this invention. The range should not be construed as limiting.

  For example, the precast floor slab 1 to which the present invention is applied may be configured such that the bolt hole 12 is provided only at the intermediate portion 11b and the bolt hole 12 is not provided at both end portions 11a. In the first laying method, in the first step, the temporary fence 3 is installed on the upper surface of the upper portion 22a of the both ends main girder 22, and in the third step, the intermediate portion 11b of the precast floor slab 1 above the intermediate main girder 21 is provided. Thus, the tip end portion 14 a of the height adjusting bolt 14 attached to the bolt hole 12 can be projected from the lower surface 1 b of the precast floor slab 1.

1: Precast floor slab 1a: Precast floor slab upper surface 1b: Precast floor slab lower surface 11a: Both end portions 11b: Intermediate portion 12: Bolt hole 13: Height adjusting bracket 13a: Outer peripheral portion 13b: Inner peripheral portion 14: Height Adjustment bolt 14a: Height adjustment bolt tip 2: Main girder 2a: Upper part of main girder 21: Intermediate main girder 21a: Upper part of intermediate main girder 22: Both ends main girder 22a: Upper end of both main girder 23: Accessory plate 23a: Bolt 3: Temporary fence 9: Bridge 9a: Ground 91: Pier 91a: Head X: Bridge axis direction Y: Bridge width direction

Claims (3)

In the precast floor slab erection method in which three or more main girders are arranged side by side in the bridge width direction of the bridge and the precast slab is erected,
A first step of installing a temporary fence on the upper surface of the intermediate main girder provided in the middle of the bridge width direction among the three or more main girder arranged side by side in the bridge width direction;
Among the three or more main girders, a bolt hole penetrating in the vertical direction is provided in a portion above the both-end main gird provided at both ends in the bridge width direction, and in the portion above the intermediate main girder A second step of installing a precast floor slab not provided with a bolt hole on the upper part of the main beam;
The tip of the height adjusting bolt attached to the bolt hole provided at the part above the both-end main girder is projected from the lower surface of the precast floor slab, thereby contacting the upper surface of the both-end main girder And a third step of adjusting the height of the precast floor slab. In the first step, among three or more steel main girders arranged side by side in the bridge width direction, a rubber temporary tack is installed on the upper surface of the intermediate main girder provided in the middle of the bridge width direction,
In the third step, a height adjusting bolt attached by being screwed from above to a height adjusting bracket embedded in the bolt hole provided in a portion above the both end main girders, Adjusting the height of the precast floor slab by rotating it with a hole and causing the tip of the height adjusting bolt to protrude from the lower surface of the precast floor slab to abut the upper surface of the main girder at both ends. The method for laying a precast slab according to claim 1. In precast floor slabs installed on top of three or more main girders arranged side by side in the bridge width direction of the bridge,
Bolt holes penetrating in the vertical direction are provided in the upper part of both end main girders provided at both ends in the bridge width direction among three or more main girders arranged side by side in the bridge width direction, and in the bridge width direction A precast floor slab characterized in that the bolt hole is not provided in a portion above a temporary fence installed on the upper surface of an intermediate main girder provided in the middle.

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