JP2020100967A - Fixed structure of main girder and precast slab and method of fixing main girder and precast slab - Google Patents

Abstract

To provide a fixed structure of a main girder and a precast slab with same number of protrusions capable of improving the strength against shear force.SOLUTION: A fixed structure 1A between a main girder 2 and a precast floor slab 3A, includes: the main girder 2; a protrusion 5A protruding upward on the main girder 2; the precast floor slab 3A having a housing 8 on the lower surface 6 for accommodating the protrusion 5A; and a filler 9 for filling the housing 8 accommodating the protrusion 5A. Since the protrusion 5A is formed of a tubular member in which one end of the opening 13 side is welded to the main girder 2, compared with the case where the protrusion 5A is a stud such as a steel rod, the welding length of the protrusion 5A to the main girder 2 with respect to the lateral projection area of the protrusion 5A can be increased. With this, the strength against the shear force of the fixed structure 1a including the main girder 2 and the precast floor slab 3A of the same number of protrusions 5A is improved.SELECTED DRAWING: Figure 3

Description

The present invention relates to a fixing structure for a main girder and a precast floor slab and a method for fixing a main girder and a precast floor slab.

In a road bridge, a main girder, a stud protruding above the main girder, a precast floor slab having a stud hole such as a box hole for accommodating the stud on the lower surface, and a filler for filling the stud hole accommodating the stud. A fixed structure of the main girder and the precast floor slab provided is proposed. For example, in Patent Document 1, a precast floor slab in which a plurality of stud holes for accommodating a stud and combining with a steel girder is formed is installed on the steel girder, and the steel girder is installed in the stud hole of the installed precast floor slab. Has been disclosed in which a stud is erected on the upper surface of and the inside of the stud hole is filled with a filling material.

JP, 2018-21403, A

By the way, generally, the shear shear force becomes large at the end of the span of the road bridge. Therefore, it is necessary to arrange a large number of studs at the end of the span in order to resist the shear shear force. However, since the space for installing the studs is limited by the flange width on the upper surface of the steel girder, it is not possible to arrange the required number of studs, which may result in failure in design.

Therefore, the present invention is a fixed structure of the main girder and the precast floor slab and a main girder and the precast that can improve the strength against the shearing force of the fixed structure of the main girder and the precast floor slab provided with the same number of protrusions. It is intended to provide a fixing method with a floor slab.

The present invention includes a main girder, a protrusion protruding above the main girder, a precast floor slab having a housing on the lower surface for housing the projection, and a filler for filling the housing containing the projection. The projecting portion has a fixed structure of a main girder and a precast floor slab, which is a tubular member in which an end on the side of one opening is welded to the main girder.

According to this configuration, the main girder, the projecting portion that projects above the main girder, the precast floor slab that has the housing portion that houses the projecting portion on the lower surface, and the filler that fills the housing portion that houses the projecting portion. In the fixed structure of the main girder and the precast floor slab, the protrusion is a tubular member whose end on the side of one opening is welded to the main girder, so that the protrusion is a stud such as a steel rod. Compared to some cases, the welding length of the protrusion to the main girder with respect to the projected area to the side of the protrusion can be made longer, and the fixing structure of the main girder and the precast floor slab with the same number of protrusions It is possible to improve the strength against shear shear force.

In this case, the protrusion is preferably a plurality of tubular members whose side surfaces are integrated with each other.

According to this configuration, since the protrusion is a plurality of tubular members whose side surfaces are integrated with each other, it is possible to further increase the welding length of the protrusion to the main girder with respect to the lateral projection area of the protrusion. Therefore, it is possible to further improve the strength against the shear shear force of the fixed structure of the main girder and the precast floor slab provided with the same number of protrusions.

In addition, it is preferable that the protruding portion has a tubular bottom portion in which an end portion on the side of the one opening portion is welded to the main girder, and a tubular extension portion that extends upward while fitting with the bottom portion. is there.

According to this configuration, the projecting portion has a tubular bottom portion whose end on the one opening side is welded to the main girder, and a tubular extending portion that extends upward while being fitted to the bottom portion. Therefore, even if the protruding portion has a long protruding length, the end portion of the tubular bottom portion on one opening side is easily welded to the main girder, and then the tubular extension portion is fitted to the bottom portion. Thus, the protrusion can be easily attached to the main girder.

Further, it is preferable that the protruding portion is a tubular member having a convex portion or a concave portion on a side surface.

According to this configuration, since the protruding portion is a tubular member having a convex portion or a concave portion on the side surface, the area where the side surface of the protruding portion and the filler contact each other increases, and the main girder and the precast floor slab are fixed. Strength can be improved.

In addition, it is preferable that the protruding portion has a larger thickness at the end portion on the side of the other opening protruding above the thickness of the end portion on the side of the one opening welded to the main girder. ..

According to this configuration, since the protruding portion has a larger thickness at the end portion on the side of the other opening projecting upward than the thickness of the end portion on the side of the one opening welded to the main girder. The strength against the force of vertically separating the main girder and the precast floor slab can be further improved.

Further, it is preferable that the boundary surface between the accommodating portion and the filler has a convex portion or a concave portion.

According to this configuration, since the boundary surface between the housing portion and the filler has a convex portion or a concave portion, the area of the boundary surface where the housing portion and the filler material contact each other is increased, and the main girder and the precast floor slab are separated from each other. The strength of fixing can be improved.

Further, it is preferable that the accommodation section is open to the lower surface of the precast floor slab and closed to the upper surface of the precast floor slab.

According to this configuration, since the storage section is open to the lower surface of the precast floor slab and closed to the upper surface of the precast floor slab, the concrete of the precast floor slab existing above the projecting section and the storage section. By the part (1), it is possible to further improve the strength against the shear shear force of the fixing structure of the main girder and the precast floor slab provided with the same number of protrusions.

Further, the present invention, the main girder to join the protrusion protruding above the main girder projection portion joining step, the floor grate installation step of installing the precast floor slab to the main girder, the protrusion joining step to the main girder In a state in which the joined protrusion is accommodated in the accommodation portion on the lower surface of the precast floor slab installed on the main girder in the floor slab installation step, a filling step of filling the accommodation portion accommodating the protrusion with a filler is provided. In the projecting part joining step, a method of fixing the main girder and the precast floor slab that joins the projecting part to the main girder by welding the end on the side of one opening of the projecting part that is a tubular member to the main girder Is.

In this case, in the protrusion joining step, it is preferable to join the protrusions, which are a plurality of tubular members whose side surfaces are integrated, to the main girder.

Further, in the projecting part joining step, a projecting part having a tubular bottom part whose end on the one opening side is welded to the main girder, and a tubular extending part extending upward while being fitted to the bottom part. To the main girder, and after welding the end on the side of one opening of the bottom part to the main girder, by fitting the extension part to the bottom part welded to the main girder, Bonding is preferred.

Further, in the protruding portion joining step, it is preferable to join the protruding portion, which is a tubular member having a convex portion or a concave portion on the side surface, to the main girder.

Further, in the protruding portion joining step, the thickness of the end portion on the side of the other opening, which protrudes upward from the thickness of the end portion on the side of one opening welded to the main girder, is larger than the thickness of the end portion. Bonding to the main girder is preferred.

In addition, in the floor slab installation step, it is preferable to install a precast floor slab having a convex portion or a concave portion on the boundary surface with the filler of the accommodating portion on the main girder.

Further, in the floor slab installation step, it is preferable to install the precast floor slab in which the accommodating portion is open to the lower surface of the precast floor slab and closed to the upper surface of the precast floor slab on the main girder.

According to the fixing structure of the main girder and the precast floor slab and the method of fixing the main girder and the precast floor slab of the present invention, the shearing force of the fixed structure between the main girder and the precast slab with the same number of protrusions The strength against can be improved.

It is a perspective view showing a fixed structure of a main girder and a precast floor slab according to the first embodiment. It is a perspective view of the vicinity of the protrusion of the fixing structure of the main girder and the precast floor slab according to the first embodiment. (A) is a vertical cross-sectional view of the vicinity of a protrusion of the fixing structure of the main girder and the precast floor slab according to the first embodiment, (B) is a plan view of the protrusion according to the first embodiment. (A) is a longitudinal sectional view showing a state after a projecting part joining step and a floor slab installation step of the method of fixing the main girder and the precast floor slab according to the first embodiment, and (B) is a first embodiment. FIG. 6 is a plan view showing a state after the step of joining the protrusions according to FIG. (A) is a vertical cross-sectional view of the vicinity of the protrusion of the fixing structure of the main girder and the precast floor slab according to the second embodiment, (B) is a plan view of the protrusion according to the second embodiment. (A) is a vertical cross-sectional view of the vicinity of the protrusion of the fixing structure of the main girder and the precast floor slab according to the third embodiment, (B) is a plan view of the protrusion according to the third embodiment. (A) is a vertical cross-sectional view of the vicinity of the protrusion of the fixing structure of the main girder and the precast floor slab according to the fourth embodiment, (B) is a plan view of the protrusion according to the fourth embodiment. (A) is a longitudinal cross-sectional view showing a state after the bottom portion of the projecting portion joining step of the method of fixing the main girder and the precast floor slab according to the fourth embodiment is welded to the main girder, and (B) is the fourth. It is a top view of the bottom part after being welded to the main girder concerning an embodiment. 8A is a vertical cross-sectional view showing a state in which the protrusion is joined to the main girder by fitting the extending portion to the bottom portion welded to the main girder of FIG. 8A, and FIG. It is a top view which shows the state which joined the protrusion to the main girder by fitting an extension part to the bottom part welded to the main girder of (B). (A) is a vertical cross-sectional view of the vicinity of the protrusion of the fixing structure of the main girder and the precast floor slab according to the fifth embodiment, (B) is a plan view of the protrusion according to the fifth embodiment. (A) is a plan view showing a step of combining two tubular members constituting a protruding portion with each other, and (B) shows a state in which two tubular members combined with each other in (A) are welded to form a protruding portion. It is a top view shown. (A) is a plan view showing a state in which a conventional stud is joined to a flange of a main girder, and (B) is a plan view showing a state in which a protrusion of the fifth embodiment is joined to a flange of a main girder. It is a longitudinal cross-sectional view near the protrusion part of the fixing structure of the main girder and the precast floor slab according to the sixth embodiment. It is a longitudinal cross-sectional view of the vicinity of the protrusion part of the fixing structure of the main girder and the precast floor slab according to the seventh embodiment. It is a perspective view which shows the precast floor slab which concerns on 7th Embodiment.

Hereinafter, an embodiment of a fixing structure for a main girder and a precast floor slab and a method for fixing a main girder and a precast floor slab according to the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, FIG. 2, FIG. 3(A), and FIG. 3(B), the main girder and precast floor slab fixing structure 1A according to the first embodiment of the present invention includes a main girder 2 and a precast floor. The plate 3A, the protrusion 5A, and the filler 9 are provided. The main girder 2 is, for example, a steel girder. The main girder 2 has a flange 4 at its upper end.

The precast floor slab 3A has a lower surface 6 and an upper surface 7. The precast floor slab 3</b>A has an accommodating portion 8 that accommodates the protruding portion 5 on the lower surface 6. In the present embodiment, the accommodating portion 8 is a box removal hole that penetrates from the opening 12 of the upper surface 7 to the lower surface 6 as in the conventional precast floor slab. The filling material 9 fills the housing portion 8 that houses the protruding portion 5A. The filler 9 is, for example, non-shrink mortar. The filler 9 is provided in a space surrounded by the flange 4 of the main girder 2, the formwork 11 provided on both side edge portions of the upper surface of the flange 4, the lower surface 6 of the precast floor slab 3A, and the housing portion 8. It is filled. In the present embodiment, the boundary surface 10 between the housing portion 8 and the filler 9 is a flat surface in the vertical direction.

The protrusion 5</b>A is joined to the flange 4 at the upper end of the main girder 2 and protrudes above the main girder 2. In the present embodiment, the protrusion 5A is not a conventional stud, but is a tubular member in which the end on the side of the one opening 13 is welded to the flange 4 of the main girder 2 by the fillet weld 15. The other opening 14 of the protrusion 5A, which is a tubular member, opens above the main girder. As shown in FIG. 3B, a filling material 9 is filled in the pipe of the protruding portion 5A which is a tubular member. In this embodiment, the protrusion 5A is a circular pipe member having a diameter of about 100 to 150 mm. The tubular member means a member in which an internal space extending in an arbitrary direction is defined by a pipe wall, and the internal space is open in the arbitrary direction and a direction opposite to the arbitrary direction. To do. The tubular member may be a tubular member having another shape such as a square tube other than the circular tube. Further, the tubular member may have an internal space partitioned by a partition or the like. In addition, a member such as a channel material may be attached to the outer surface of the tubular member.

Hereinafter, a method of fixing the main girder and the precast floor slab of the present embodiment will be described. As shown in FIGS. 4(A) and 4(B), a projecting part joining step of joining the projecting part 5A projecting above the main beam 2 to the main beam 2 and a precast floor slab 3A installed on the main beam 2. The floor slab installation process is performed. In the protruding portion joining step, the protruding portion 5A is joined to the main girder 2 by welding the end of the protruding portion 5A, which is a tubular member, on the side of the one opening 13 to the flange 4 of the main girder 2. As shown in FIG. 4(B), in the projecting part joining step, the outer peripheral side of the end of the projecting part 5A, which is a tubular member, on the side of the opening 13 is welded to the flange 4 of the main girder 2 by the fillet welding part 15. The inner peripheral side is welded to the flange 4 of the main girder 2 by the fillet welded portion 16. The steps of the floor slab installation step and the protrusion joining step may be either before or after.

As shown in FIGS. 3(A) and 3(B), the lower surface of the precast floor slab 3A in which the protrusion 5A joined to the main girder 2 in the protrusion joining step is installed on the main girder 2 in the floor slab installation step In the state of being accommodated in the accommodating portion 8 of 6, the accommodating portion 8 accommodating the protruding portion 5A is filled with the filler 9. By the filling step, the filling material 9 is also filled in the pipe of the protruding portion 5A that is the tubular member housed in the housing unit 8. After the filler 9 is solidified, the fixing structure 1A for the main girder 2 and the precast floor slab 3A of the present embodiment is completed.

According to the present embodiment, the main girder 2, the protrusion 5A protruding above the main girder 2, the precast floor slab 3A having the accommodating portion 8 for accommodating the protrusion 5A on the lower surface 6, and the protrusion 5A are accommodated. In the fixed structure 1A of the main girder 2 and the precast floor slab 3A that are provided with the filling material 9 that fills the accommodating portion 8 described above, the protrusion 5A is welded to the main girder 2 at the end on the side of the one opening 13. Since the protruding member 5A is a tubular member, the welding length of the protruding member 5A to the main girder 2 with respect to the laterally projected area of the protruding member 5A is increased as compared with the case where the protruding member 5A is a stud such as a steel rod. Therefore, the strength against the shearing force of the fixed structure 1A of the main girder 2 and the precast floor slab 3A having the same number of protrusions 5A can be improved.

That is, in the protruding portion joining step of the present embodiment, the outer peripheral side of the end portion of the protruding portion 5A, which is a tubular member, on the side of the opening 13 is welded to the flange 4 of the main girder 2 by the fillet welded portion 15, and the inner peripheral side is welded. It is welded to the flange 4 of the main girder 2 by the fillet weld 16. For this reason, welding is performed between the outer peripheral side and the inner peripheral side of the end on the opening side of the tubular member, as compared with the conventional stud such as a steel rod that is welded only on the outer peripheral side of the end. The welding length can be increased.

Further, in the present embodiment, since the filler 9 is filled also in the pipe of the protruding portion 5A that is the tubular member housed in the housing portion 8, the shear structure of the fixing structure 1A between the main girder 2 and the precast floor slab 3A is sheared. The strength against force can be improved. Further, since the protrusion 5A is a tubular member, it is possible to reduce the weight as compared with the case where the protrusion 5A is a stud such as a steel rod.

The second embodiment of the present invention will be described below. As shown in FIGS. 5(A) and 5(B), in the fixing structure 1B of the main girder and the precast floor slab of the present embodiment, the protruding portion 5B is a tubular member having the convex portion 17 and the concave portion 18 on the side surface. Is. In the present embodiment, for example, the convex portion 17 and the concave portion 18 can be formed on the side surface of the tubular member by welding a reinforcing bar or the like to the side surface of the tubular member.

In the example of FIGS. 5(A) and 5(B), a reinforcing bar extending in the up-down direction is provided between the end on the side of the opening 13 and the end on the side of the opening 14 on the outer peripheral surface of the tubular member. It is welded. Further, a plurality of reinforcing bars extending along the lateral direction so as to surround the outer peripheral surface of the tubular member are welded. The protruding portion 5B may have only the convex portion 17 or only the concave portion 18. Further, the convex portion 17 or the concave portion 18 may be formed on the side surface of the tubular member by joining another member such as a channel material or by casting.

In the protruding portion joining step of the method of fixing the main girder and the precast floor slab of the present embodiment, in the protruding portion joining step, the protruding portion 5B, which is a tubular member having the convex portion 17 or the concave portion 18 on the side surface, is the flange of the main girder 2. It is joined to 4. Other than the above, the second embodiment is the same as the first embodiment.

According to the present embodiment, since the protrusion 5B is a tubular member having the protrusion 17 or the recess 18 on the side surface, the area where the side face of the protrusion 5B and the filler 9 contact each other increases, and the main girder 2 It is possible to improve the strength of fixing the precast floor slab 3A with the precast floor slab.

The third embodiment of the present invention will be described below. As shown in FIGS. 6(A) and 6(B), in the fixing structure 1C of the main girder and the precast floor slab of the present embodiment, one of the protrusions 5C is welded to the flange 4 of the main girder 2. The thickness of the end portion on the side of the other opening portion 14 protruding upward is larger than the thickness of the end portion on the side of the opening portion 13 side. In the example of FIG. 6(A) and FIG. 6(B), as the end portion on the side of one opening portion 13 welded to the main girder 2 reaches the end portion on the side of the other opening portion 14 protruding upward, The diameter of the protrusion 5C, which is a tubular member, increases uniformly. The side surface of the protrusion 5C, which is a tubular member, has a tapered shape in a side view.

In addition, in the present embodiment, due to another shape, the end portion on the side of the other opening portion 14 protruding upward from the thickness of the end portion on the side of the one opening portion 13 welded to the flange 4 of the main girder 2 is formed. The thickness of may be thicker. For example, the diameter of the protrusion 5C does not increase uniformly from the end on the side of the one opening 13 to the end on the side of the other opening 14, and the side of the other opening 14 protruding upward The diameter may be expanded only in the vicinity of the end portion of. Further, since a member such as a reinforcing bar is welded to the upper portion of the protruding portion 5A as in the first embodiment, the thickness of the end portion on the side of one opening 13 welded to the flange 4 of the main girder 2 is smaller than the thickness of the end portion. Also, the thickness of the end portion on the side of the other opening 14 protruding upward may be thicker.

In the projecting portion joining step of the method of fixing the main girder and the precast floor slab of the present embodiment, the other opening portion projecting above the thickness of the end portion on the side of the one opening portion 13 welded to the main girder 2 is projected. The protruding portion 5C having a thicker end on the 14 side is joined to the main girder 2. Other than the above, the second embodiment is the same as the first embodiment. It should be noted that the thickness of the end portion on the side of the other opening portion 14 that is protruded above the thickness of the end portion on the side of the one opening portion 13 welded to the main girder 2 of the present embodiment is thicker than the thickness of the protruding portion. The configuration of 5C may be applied to the second embodiment.

In the present embodiment, the protruding portion 5C is the thickness of the end portion on the side of the other opening portion 14 that is protruded above the thickness of the end portion on the side of the one opening portion 13 welded to the main girder 2. Is thick, the strength against the force of vertically separating the main girder 2 and the precast floor slab 3A can be further improved.

The fourth embodiment of the present invention will be described below. As shown in FIG. 7(A) and FIG. 7(B), in the fixing structure 1D of the main girder and the precast floor slab of the present embodiment, the protrusion 5D is mainly the end portion on the side of the one opening 20. It has a tubular bottom portion 19 welded to the flange 4 of the girder 2 and a tubular extension portion 22 that extends upward while fitting with the bottom portion 19.

In the example of FIG. 7(A) and FIG. 7(B), both the bottom portion 19 and the extending portion 22 have a tubular shape. The end portion of the extending portion 22 on the side of the one opening 23 and the other opening portion is longer than the length from the end portion on the side of the one opening portion 20 of the bottom portion 19 to the end portion on the side of the other opening portion 21. The length to the end on the side of 24 is long. The outer peripheral surface of the bottom portion 19 on the opening 21 side and the inner peripheral surface of the extending portion 22 on the opening 23 side are fitted to each other. However, the shapes of the bottom portion 19 and the extending portion 22 and the form of fitting between the bottom portion 19 and the extending portion 22 may be other forms.

Hereinafter, a method of fixing the main girder and the precast floor slab of the present embodiment will be described. In the present embodiment, in the projecting portion joining step, the end portion on the side of the one opening 20 is tubular-shaped bottom portion 19 welded to the flange 4 of the main girder 2 and extends upward while being fitted to the bottom portion 19. A protrusion 5D having a tubular extension 22 is joined to the main girder 2. As shown in FIGS. 8(A) and 8(B), in the protrusion joining step, first, one end of the bottom 19 on the side of the opening 20 is welded to the flange 4 of the main girder 2. The welding of the bottom portion 19 is performed in the same manner as the welding of the protrusion 5A to the flange 4 of the main girder 2 of the first embodiment.

As shown in FIG. 9(A) and FIG. 9(B), after welding the end portion of the bottom portion 19 on one side of the opening 20 to the flange 4 of the main girder 2, it is welded to the flange 4 of the main girder 2. By fitting the extending portion 22 to the bottom portion 19, the protruding portion 5D is joined to the flange of the main girder 2. In the above description, the protrusion joining process is performed before the floor slab installing process, but the floor slab installing process and the protrusion joining process may be performed either before or after. Further, the bottom portion 19 and the extending portion 22 of this embodiment may be applied to the above-described second embodiment or third embodiment.

In the present embodiment, the protruding portion 5D has a tubular bottom portion 19 in which the end portion on the side of the one opening portion 20 is welded to the main girder 2, and a tubular extension portion that extends upward while fitting with the bottom portion 19. Since it has the portion 22, even if the protruding portion 5D has a long protruding length, the end portion of the tubular bottom portion 19 on the side of the one opening 20 is easily welded to the main girder 2 and then the bottom portion 19 is formed. By fitting the tubular extending portion 22 in, the protrusion 5D can be easily attached to the main girder 2.

The fifth embodiment of the present invention will be described below. As shown in FIGS. 10(A) and 10(B), in the fixing structure 1E of the main girder and the precast floor slab of the present embodiment, the protrusion 5E has a plurality of tubular members whose side surfaces 27 are integrated with each other. Is. As shown in FIG. 10(B) and FIG. 11(A), the protruding portion 5E is composed of two tubular members.

Each of the two tubular members includes a slit portion 28 on a side surface that extends along a direction from an end portion on the side of one opening portion 25 to an end portion on the side of the other opening portion 26. The two tubular members are fitted to each other via the slit portion 28. As shown in FIG. 10(A), FIG. 10(B) and FIG. 11(B), the two tubular members fitted to each other through the slit portion 28 are welded to each other by the fillet weld portion 29. As a result, the protruding portion 5E is formed.

In the protruding portion joining step of the method for fixing the main girder and the precast floor slab of the present embodiment, in the protruding portion joining step, as described above, in the protruding portion joining step, the plurality of tubular members whose side surfaces 27 are integrated with each other are formed. The protrusion 5E is joined to the flange 4 of the main girder 2. The protrusion 5E is joined to the flange 4 of the main girder 2 in the same manner as in the first embodiment. The protrusion 5E may be composed of three or more tubular members. In addition, the configuration of the protruding portion 5E, which is a plurality of tubular members in which the side surfaces 27 are integrated with each other, of the present embodiment may be applied to the second to fourth embodiments described above.

According to the present embodiment, since the protruding portion 5E is a plurality of tubular members whose side surfaces 27 are integrated with each other, the welding length of the protruding portion 5E to the main girder 2 with respect to the laterally projected area of the protruding portion 5E. Since it is possible to further increase the length, it is possible to further improve the strength against the shear shear force of the fixed structure of the main girder 2 and the precast floor slab 3A having the same number of protrusions 5E.

The yield strength of the slip prevention structure increases as the number of slip prevention pieces such as studs increases. However, as shown in FIG. 12A, the headed studs 51 and 52 are adjacent to each other on the flange 4 of the main girder 2 which extends in the bridge axis direction D ₁ and has a width in the flange width direction D _2. It cannot be welded and placed on the flange 4 without a certain distance d with a sense. Further, since the stopper is arranged in a limited space on the flange 4 of the main girder 2, when the headed studs 51, 52 and the like are used, the necessary number of headed studs 51, 52 and the like are arranged. There are things you can't do. On the other hand, as shown in FIG. 12(B), according to the present embodiment, a plurality of tubular members are combined and installed as a large displacement stopper, thereby saving the installation area and high resistance to shearing. Can be secured.

Hereinafter, a sixth embodiment of the present invention will be described. As shown in FIG. 13, in the fixing structure 1F of the main girder and the precast floor slab of the present embodiment, the boundary surface 10 between the accommodating portion 8 and the filler 9 has the convex portion 30 and the concave portion 31. In the floor slab installation step of the method of fixing the main girder and the precast floor slab of the present embodiment, the precast floor slab 3B having the convex portion 30 and the concave portion 31 in the boundary surface 10 with the filling material 9 of the housing portion 8 is the main girder 2. It is installed on the flange 4. The precast floor slab 3B in which the boundary surface 10 with the filling material 9 of the housing portion 8 of the present embodiment has the convex portion 30 and the concave portion 31 may be applied to the second to fifth embodiments described above. ..

According to the present embodiment, the boundary surface 10 between the housing portion 8 and the filling material 9 has the convex portion 30 or the concave portion 31, so that the area of the boundary surface 10 where the housing portion 8 and the filling material 9 contact each other increases. The strength for fixing the main girder 2 and the precast floor slab 3B can be improved.

The seventh embodiment of the present invention will be described below. As shown in FIG. 14, in the fixed structure 1G of the main girder and the precast floor slab of the present embodiment, the housing portion 8 is opened to the lower surface 6 of the precast floor slab 3C and is placed on the upper surface 7 of the precast floor slab 3C. It has been closed. As shown in FIG. 15, the precast floor slab 3C of the present embodiment is called a waffle type floor slab, for example.

The precast floor slab 3C has a plurality of storage portions 8 defined by the grid-shaped ribs 32 protruding on the lower surface 6. In the present embodiment, a part of the plurality of accommodating portions 8 accommodates the protruding portion 5A. In the precast floor slab 3C, reinforcing bars 33 are arranged along the ribs 32. The precast floor slab 3C is formed of, for example, ultra high strength fiber reinforced concrete (UFC).

An example of the properties of the ultra high strength fiber reinforced concrete will be described below. This ultra-high-strength fiber-reinforced concrete is obtained by curing a mixture containing cement, aggregate, mixing water, a chemical admixture for concrete, and reinforcing fibers. The cement is, for example, normal Portland cement, early-strength Portland cement, moderate heat Portland cement, sulfate resistant Portland cement, or low heat Portland cement.

As an example, the above-mentioned aggregate has a particle size of 2.5 mm or less, an absolute dry density of 2.5 g/cm ³ or more, a water absorption rate of 3.0% or less, a clay mass amount of 1.0% or less, and a fine particle content of 2.0%. The following is an aggregate having a NaCl content of 0.02% or less. This aggregate is one in which the test result of organic impurities by the method for testing organic impurities of fine aggregate specified in JIS A 1105 is "pale". In addition, this aggregate has a stability of 10% or less according to the stability test method of the aggregate with sodium sulfate specified in JIS A 1122, and further has an alkali silica reactivity specified in Annex 1 of JIS A 5308. It is an aggregate that is classified by A.

The above-mentioned mixing water is, for example, mixing water other than the recovered water specified in JSCE-B 101-2005. The above-mentioned chemical admixture for concrete is a high-performance water reducing agent specified in JIS A 6204. The above-mentioned reinforcing fiber is a fiber having a diameter of 0.1 to 0.25 mm, a length of 10 to 24 mm, and a tensile strength of 2×10 ³ N/mm ² or more. The reinforcing fibers described above may be, for example, steel fibers, high strength aramid fibers, high density polyethylene fibers, or carbon fibers.

The ultra-high-strength fiber-reinforced concrete has, for example, a matrix composed of a binder made of Portland cement, a pozzolanic material, and an ethrin guide-forming material, an aggregate having a particle diameter of 2.5 mm or less, water, and a water reducing agent. There is. The reinforcing fibers are steel fibers having a diameter of 0.2 mm, a length of 15 mm (manufacturing error of less than ±2 mm), and a tensile strength of 2×10 ³ N/mm ² or more, a diameter of 0.2 mm, and a length of 22 mm (manufacturing). Error of less than ±2 mm), and a mixture of steel fibers having a tensile strength of 2×10 ³ N/mm ² or more, 1.75 vol. % May be mixed. In addition, the characteristic values of the ultra-high-strength fiber-reinforced concrete after hardening are as follows: compressive strength 150 N/mm ² or more, cracking strength 4 N/mm ² or more, tensile strength 5 N/mm ² or more, water permeability coefficient 1×10 ⁻¹¹ cm/ s, chloride ion diffusion coefficient less than 0.14 cm ² /year, and abrasion coefficient less than 240 mm ³ /cm ² .

The standard composition of ultra-high strength fiber reinforced concrete has a flow value of 250±20 mm, a mixing water ratio to the binder of 15%, an air content of 2.0%, a mixing water of 195 kg/m ³ , a binder of 1287 kg/m. ³ , aggregate 905 kg/m ³ , high-performance water reducing agent 32.2 kg/m ³ , and reinforcing fiber 137.4 kg/m ³ (1.75 vol.%).

In the floor slab installation step of the method of fixing the main girder and the precast floor slab of the present embodiment, the housing portion 8 is opened to the lower surface 6 of the precast floor slab 3C and closed to the upper surface 7 of the precast floor slab 3C. The precast floor slab 3C is installed on the main girder 2. The precast floor slab 3C has a housing portion 8 that is open to the lower surface 6 of the precast floor slab 3C and is closed to the upper surface 7 of the precast floor slab 3C only at a position corresponding to the protruding portion 5A. You may have. Further, as shown in FIG. 14, the accommodation portion 8 may be provided with a discharge hole portion 34 for the filler 9 that communicates from the accommodation portion 8 to the upper surface 7. The precast floor slab 3C having the housing portion 8 which is open to the lower surface 6 and closed to the upper surface 7 of the present embodiment may be applied to the second to sixth embodiments described above.

In the present embodiment, since the housing portion 8 is open to the lower surface 6 of the precast floor slab 3C and closed to the upper surface 7 of the precast floor slab 3C, it is above the projecting portion 5A and the housing portion 8. Depending on the concrete portion of the precast floor slab 3C, the strength of the fixed structure of the main girder 2 and the precast floor slab 3C having the same number of protrusions 5A against the shear shear force can be further improved.

In addition, in the present embodiment, the precast floor slab 3C has the plurality of housing portions 8 on the lower surface 6, so that the precast floor slab 3C can be lightened. In addition, in the present embodiment, the precast floor slab 3C is formed of ultra-high strength fiber reinforced concrete, so the strength of the precast floor slab 3C can be improved.

The present invention can be implemented in various forms including various modifications and improvements based on the knowledge of those skilled in the art, including the above-described embodiments. Further, it is also possible to configure the modified example by utilizing the technical matters described in the above-mentioned embodiment.

1A, 1B, 1C, 1D, 1E, 1F, 1G... Fixed structure, 2... Main girder, 3A, 3B, 3C... Precast floor slab, 4... Flange, 5A, 5B, 5C, 5D, 5E... Projection, 6 ... lower surface, 7... upper surface, 8... accommodating portion, 9... filling material, 10... boundary surface, 11... formwork, 12... opening portion, 13, 14... opening portion, 15, 16... fillet weld portion, 17... Convex portion, 18... Recessed portion, 19... Bottom portion, 20, 21... Opening portion, 22... Extension portion, 23, 24... Opening portion, 25, 26... Opening portion, 27... Side surface, 28... Slit portion, 29... Corner weld portion, 30 ... protruding portion, 31 ... recess, 32 ... rib, 33 ... reinforcing steel, 34 ... discharge holes, 51, 52 headed stud, D 1 _... bridge axis direction, D 2 _... flange width direction, d …distance.

Claims (14)

Main girder,
A protrusion protruding above the main girder,
A precast floor slab having a housing portion for housing the protruding portion on the lower surface,
A filling material that fills the housing portion that houses the protruding portion,
Equipped with
The projecting portion is a fixed structure of a main girder and a precast floor slab, which is a tubular member in which an end on the side of one opening is welded to the main girder. The fixing structure for a main girder and a precast floor slab according to claim 1, wherein the projecting portion is a plurality of tubular members whose side surfaces are integrated with each other. The projecting portion has a tubular bottom portion whose end on the one opening side is welded to the main girder, and a tubular extending portion that extends upward while fitting with the bottom portion. Alternatively, the fixed structure of the main girder described in 2 and the precast floor slab. The fixing structure for a main girder and a precast floor slab according to any one of claims 1 to 3, wherein the protruding portion is a tubular member having a convex portion or a concave portion on a side surface. The thickness of the protruding portion is larger at the end portion on the side of the other opening portion protruding above the thickness of the end portion on the side of the one opening portion welded to the main girder. A fixed structure of the main girder and the precast floor slab according to any one of 4 above. The fixing structure for a main girder and a precast floor slab according to any one of claims 1 to 5, wherein a boundary surface between the accommodation portion and the filling material has a convex portion or a concave portion. The main girder and the precast floor according to any one of claims 1 to 6, wherein the accommodation portion is open to the lower surface of the precast floor slab and closed to the upper surface of the precast floor slab. Fixed structure with plate. A protruding portion joining step of joining a protruding portion protruding above the main girder to the main girder,
A slab installation step of installing a precast slab on the main girder,
The protrusion is accommodated in a state where the protrusion joined to the main girder in the protrusion joining step is accommodated in the accommodating portion on the lower surface of the precast floor slab installed on the main girder in the floor slab installing step. And a filling step of filling the accommodating portion with a filling material,
Equipped with
In the protruding portion joining step, an end portion on the side of one opening of the protruding portion which is a tubular member is welded to the main girder to join the protruding portion to the main girder, a main girder and a precast floor. How to fix the plate. The method for fixing a main girder and a precast floor slab according to claim 8, wherein, in the projecting part joining step, the projecting parts, which are a plurality of tubular members whose side surfaces are integrated with each other, are joined to the main girder. In the protrusion joining step,
One end of the opening side is joined to the main girder with the tubular bottom that is welded to the main girder, and the protrusion having a tubular extension that extends upward while fitting with the bottom. Then
After welding one end of the bottom portion on the side of the opening to the main girder, by fitting the extending portion to the bottom portion welded to the main girder, the protrusion is joined to the main girder. A method for fixing the main girder and the precast floor slab according to claim 8 or 9. The main girder and the precast floor slab according to any one of claims 8 to 10, wherein in the projecting part joining step, the projecting part, which is a tubular member having a convex part or a concave part on a side surface, is joined to the main girder. Fixing method. In the protruding portion joining step, the thickness of the end portion on the side of the one opening portion, which is welded to the main girder, is larger than the thickness of the end portion on the side of the other opening portion that is protruded upward. The method for fixing the main girder and the precast floor slab according to any one of claims 8 to 11, wherein is joined to the main girder. 13. In the floor slab installation step, the precast floor slab having a convex portion or a concave portion on the boundary surface with the filling material of the accommodating portion is installed on the main girder. Fixing method for main girder and precast floor slab. In the floor slab installation step, the accommodating portion is opened to the lower surface of the precast floor slab, the precast floor slab that is closed to the upper surface of the precast floor slab is installed in the main girder, A method for fixing the main girder and the precast floor slab according to any one of claims 8 to 13.

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