JP7178895B2 - Fixing structure between main girder and precast floor slab and fixing method between main girder and precast floor slab - Google Patents

Description

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

A road bridge consists of a main girder, a stud projecting upward from the main girder, a precast floor slab having stud holes such as box holes to accommodate the studs on the lower surface, and a filler material to fill the stud holes that accommodate the studs. A fixed structure with a main girder and a precast floor slab is proposed. For example, in Patent Document 1, a precast floor slab formed with a plurality of stud holes for accommodating studs and combining with the steel girder is installed on the steel girder, and the steel girder is placed in the stud hole of the installed precast floor slab. A method is disclosed in which a stud is erected on the upper surface of the hole and the inside of the stud hole is filled with a filler.

Japanese Unexamined Patent Application Publication No. 2018-21403

By the way, in general, shear force increases at the end of the span of a highway bridge. Therefore, the ends of the span must be studded with a number of studs to resist shear shear forces. However, the space for installing the studs is limited by the width of the flange on the upper surface of the steel girder, so the required number of studs cannot be placed, and the design may not be viable.

Therefore, the present invention provides a fixing structure between a main girder and a precast floor slab and a main girder and precast floor slab fixing structure that can improve the strength against shear force of a main girder and precast floor slab fixing structure having the same number of protrusions. An object is to provide a fixing method with a floor slab.

The present invention comprises a main girder, a projecting portion projecting upward from the main girder, a precast floor slab having an accommodating portion for accommodating the projecting portion on the lower surface, and a filler for filling the accommodating portion accommodating the projecting portion. The protruding portion is a fixed structure between the main girder, which is a tubular member whose end on one opening side is welded to the main girder, and the precast floor slab.

According to this configuration, the main girder, the projecting portion projecting upward from the main girder, the precast floor slab having an accommodating portion for accommodating the projecting portion on the lower surface, and the filling material for filling the accommodating portion accommodating the projecting portion. In the fixed structure of the main girder and the precast floor slab, the protruding part is a tubular member welded to the main girder at one end on the opening side, so the protruding part is a stud such as a steel rod. Compared to other cases, it is possible to lengthen the welding length of the projecting part to the main girder relative to the projected area of the projecting part to the side, and the fixed structure of the main girder and the precast floor slab with the same number of projecting parts It is possible to improve the strength against the shear force of the

In this case, it is preferable that the protrusions are a plurality of tubular members whose side faces are integrated with each other.

According to this configuration, since the projecting portion is a plurality of tubular members whose side surfaces are integrated with each other, the welding length of the projecting portion to the main girder with respect to the lateral projected area of the projecting portion can be further increased. Therefore, it is possible to further improve the strength of the fixing structure between the main girder and the precast floor slab, which have the same number of projections, against shear force.

In addition, it is preferable that the protruding portion has a tubular bottom portion with one opening side end welded to the main girder, and a tubular extension portion extending upward while being fitted with the bottom portion. be.

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

Moreover, it is preferable that the protrusion is a tubular member having a protrusion or a recess on the side surface.

According to this configuration, since the protrusion is a tubular member having a protrusion or a recess on the side surface, the contact area between the side surface of the protrusion and the filler material increases, thereby fixing the main girder and the precast floor slab. You can improve the strength to do.

In addition, it is preferable that the thickness of the protruding portion is thicker at the end on the side of the other opening that projects upward than the thickness of the end on the side of the opening welded to the main girder. .

According to this configuration, the protruding portion is thicker at the end on the side of the opening that protrudes upward than the end on the side of the opening welded to the main girder. , the strength against the force separating the main girder and the precast floor slab in the vertical direction can be further improved.

Moreover, it is preferable that the interface between the containing 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 recess, the area of the boundary surface where the housing portion and the filler are in contact with each other increases, and the main girder and the precast floor slab are separated. The fixing strength can be improved.

Moreover, it is preferable that 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.

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 protrusion and the storage section , it is possible to further improve the strength against shear force of the fixed structure of the main girder and the precast floor slab, which have the same number of protrusions.

In addition, the present invention includes a projecting portion joining step of joining projecting portions projecting above the main girder to the main girder, a floor slab installing step of installing a precast floor slab on the main girder, and a projecting portion joining step to the main girder. a filling step of filling the accommodation portion accommodating the protrusion with a filler in a state in which the jointed 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; , In the projecting part joining process, the projecting part is joined to the main girder by welding the end of the projecting part, which is a tubular member, on one side of the opening 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 faces are integrated with each other, to the main girder.

In addition, in the projecting part joining process, the projecting part has a tubular bottom part whose end on one opening side is welded to the main girder and a tubular extension part that extends upward while fitting with the bottom part. is joined to the main girder, and the end on the one opening side of the bottom is welded to the main girder. Bonding is preferred.

Moreover, in the protrusion joining step, it is preferable to join the protrusion, which is a tubular member having a protrusion or a recess on the side surface, to the main girder.

In addition, in the projecting part joining process, the projecting part welded to the main girder is welded to the main girder, and the thickness of the edge on the other opening side is thicker than the thickness of the edge on the other opening side. Bonding to the main girder is preferred.

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 between the filling material of the storage portion and the main girder.

Further, in the floor slab installation step, it is preferable to install the precast floor slabs, in which 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, on the main girder.

According to the fixing structure of the main girder and the precast floor slab and the fixing method of the main girder and the precast floor slab of the present invention, the shear force of the fixing structure of the main girder and the precast floor slab having the same number of protrusions It can improve the strength against

Fig. 2 is a perspective view showing a fixing structure between a main girder and a precast floor slab according to the first embodiment; Fig. 4 is a perspective view of the vicinity of a projecting portion of the fixing structure between 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 protruding portion of the fixing structure between the main girder and the precast floor slab according to the first embodiment, and (B) is a plan view of the protruding portion according to the first embodiment. (A) is a vertical cross-sectional view showing a state after a projecting portion joining step and a floor slab installation step of a method of fixing a main girder and a precast floor slab according to the first embodiment, and (B) is the first embodiment. Fig. 10 is a plan view showing a state after the protrusion joining process of the protrusion according to Fig. 3; (A) is a vertical cross-sectional view of the vicinity of a projecting portion of a fixing structure between a main girder and a precast floor slab according to a second embodiment, and (B) is a plan view of the projecting portion according to the second embodiment. (A) is a vertical cross-sectional view of the vicinity of a projecting portion of a fixing structure between a main girder and a precast floor slab according to a third embodiment, and (B) is a plan view of the projecting portion according to the third embodiment. (A) is a vertical cross-sectional view of the vicinity of a projecting portion of a fixing structure between a main girder and a precast floor slab according to a fourth embodiment, and (B) is a plan view of the projecting portion according to the fourth embodiment. (A) is a vertical cross-sectional view showing a state after the bottom is welded to the main girder in a projecting portion joining step of a method of fixing the main girder and the precast floor slab according to the fourth embodiment, and (B) is a fourth embodiment. It is a top view of the bottom after being welded to the main girder according to the embodiment. 8(A) is a vertical cross-sectional view showing a state in which the protruding portion is joined to the main girder by fitting the extending portion to the bottom welded to the main girder of FIG. 8(A), and FIG. 8(B) is FIG. FIG. 4B is a plan view showing a state in which the projecting portion is joined to the main girder by fitting the extending portion to the bottom portion welded to the main girder of FIG. (A) is a vertical cross-sectional view of the vicinity of a projecting portion of a fixing structure between a main girder and a precast floor slab according to a fifth embodiment, and (B) is a plan view of the projecting portion according to the fifth embodiment. (A) is a plan view showing a process of combining two tubular members that form a protrusion, and (B) shows a state in which the protrusion is formed by welding the two tubular members combined in (A). It is a plan view showing. (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 the flange of the main girder. FIG. 11 is a vertical cross-sectional view of the vicinity of a protruding portion of the fixing structure between the main girder and the precast floor slab according to the sixth embodiment. FIG. 12 is a vertical cross-sectional view of the vicinity of a projecting portion of the fixing structure between the main girder and the precast floor slab according to the seventh embodiment. FIG. 11 is a perspective view showing a precast floor slab according to a seventh embodiment;

EMBODIMENT OF THE INVENTION Hereafter, embodiment of the fixing structure of a main girder and a precast floor slab and the fixing method of a main girder and a precast floor slab which concerns on this invention is described in detail, referring drawings. As shown in FIGS. 1, 2, 3(A) and 3(B), a fixing structure 1A for a main girder and a precast floor slab according to the first embodiment of the present invention includes a main girder 2, a precast floor A plate 3A, a protrusion 5A and a 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. As shown in FIG. The precast floor slab 3</b>A has a housing portion 8 for housing the projecting portion 5 on the lower surface 6 . In the present embodiment, the housing portion 8 is a box punched hole penetrating 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 accommodating portion 8 that accommodates the projecting portion 5A. The filler 9 is, for example, non-shrinkage mortar. The filler 9 is placed in a space surrounded by the flange 4 of the main girder 2, the formwork 11 provided on both side edges of the upper surface of the flange 4, the lower surface 6 of the precast floor slab 3A, and the storage section 8. filled. In this embodiment, the boundary surface 10 between the containing portion 8 and the filler 9 is a vertically flat surface.

The protruding portion 5A is joined to the upper end flange 4 of the main girder 2 and protrudes upward from the main girder 2 . In this embodiment, the protruding portion 5A is not a conventional stud, but a tubular member having one opening 13 side end welded to the flange 4 of the main girder 2 by a fillet weld 15 . The other opening 14 of the projecting portion 5A, which is a tubular member, opens above the main girder. As shown in FIG. 3(B), a filling material 9 is filled in the tube of the projecting portion 5A, which is a tubular member. In this embodiment, the projecting portion 5A is a cylindrical member having a diameter of approximately 100 to 150 mm. In addition, 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 in a direction opposite to the arbitrary direction. do. The tubular member may be a tubular member having other shapes such as a rectangular tube, in addition to the circular tube. Further, the inner space of the tubular member may be partitioned by a partition or the like. Further, the tubular member may have a member such as a channel material attached to its outer surface.

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

As shown in FIGS. 3(A) and 3(B), the projecting portion 5A joined to the main girder 2 in the projecting portion joining step is attached to the lower surface of the precast floor slab 3A installed to the main girder 2 in the floor slab installing step. 6, a filling step is performed in which the accommodating portion 8 accommodating the protruding portion 5A is filled with the filling material 9. As shown in FIG. Through the filling step, the filling material 9 is also filled into the tube of the projecting portion 5</b>A, which is a tubular member housed in the housing portion 8 . After solidification of the filler 9, the fixing structure 1A of the main girder 2 and the precast floor slab 3A of this embodiment is completed.

According to this embodiment, the main girder 2, the protruding portion 5A projecting upward from the main girder 2, the precast floor slab 3A having the accommodation portion 8 for accommodating the protruding portion 5A on the lower surface 6, and the protruding portion 5A are accommodated. In the fixing structure 1A between the main girder 2 and the precast floor slab 3A, which includes the filling material 9 that fills the accommodating portion 8, the protruding portion 5A is welded to the main girder 2 at one end on the opening 13 side. Therefore, compared to the case where the projecting portion 5A is a stud such as a steel bar, the welding length of the projecting portion 5A to the main girder 2 with respect to the lateral projected area of the projecting portion 5A can be increased. Therefore, it is possible to improve the strength of the fixing structure 1A between the main girder 2 and the precast floor slab 3A having the same number of protrusions 5A against shear force.

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

In addition, in this embodiment, since the filling material 9 is also filled in the tube of the projecting portion 5A, which is a tubular member accommodated in the accommodating portion 8, shear shear of the fixed structure 1A between the main girder 2 and the precast floor slab 3A is minimized. Strength against force can be improved. Moreover, since the projecting portion 5A is a tubular member, the weight can be reduced as compared with the case where the projecting portion 5A is a stud such as a steel bar.

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

In the example of FIGS. 5A and 5B, a reinforcing bar extending in the vertical direction is provided between the end on the opening 13 side and the end on the opening 14 side of the outer peripheral surface of the tubular member. Welded. Also, a plurality of reinforcing bars are welded so as to extend along the lateral direction so as to surround the outer peripheral surface of the tubular member. In addition, the projecting portion 5B may have only the projecting portion 17 or only the recessed portion 18 . Also, the protrusions 17 or the recesses 18 may be formed on the side surface of the tubular member by joining other members such as channel material or by casting.

In the projecting portion joining step of the method of fixing the main girder and the precast floor slab of the present embodiment, the projecting portion 5B, which is a tubular member having a projecting portion 17 or a recessed portion 18 on the side surface, is attached to the flange of the main girder 2. 4. Except for the above, this embodiment is the same as the first embodiment.

According to this embodiment, since the projecting portion 5B is a tubular member having the projecting portion 17 or the recessed portion 18 on the side surface, the contact area between the side surface of the projecting portion 5B and the filler 9 increases, and the main girder 2 and the precast floor slab 3A can be improved in strength.

A third embodiment of the present invention will be described below. As shown in FIGS. 6A and 6B, in the fixing structure 1C of the main girder and the precast floor slab of the present embodiment, the projecting portion 5C is welded to the flange 4 of the main girder 2. The thickness of the end on the side of the other opening 14 protruding upward is thicker than the thickness of the end on the side of the opening 13 . 6(A) and 6(B), from the end on the side of one opening 13 welded to the main girder 2 to the end on the side of the other opening 14 projecting upward, The diameter of the projecting portion 5C, which is a tubular member, increases uniformly. The side surface of the projecting portion 5C, which is a tubular member, is tapered when viewed from the side.

In this embodiment, the other opening 14 side end projecting upwards from the thickness of the opening 13 side end welded to the flange 4 of the main girder 2 has another shape. thickness may be thicker. For example, the diameter of the protruding portion 5C does not uniformly increase from the end on the one opening 13 side to the end on the other opening 14 side, and the other opening 14 side protruding upward The diameter may be expanded only in the vicinity of the end of the . In addition, by welding a member such as a reinforcing bar to the upper portion of the projecting portion 5A as in the first embodiment, the thickness of the end portion on the one side of the opening portion 13 welded to the flange 4 of the main girder 2 is reduced. The thickness of the end on the side of the other opening 14 projecting upward may be thicker.

In the projecting part joining process of the fixing method of the main girder and the precast floor slab of this embodiment, the other opening projecting upwards from the thickness of the end on the one side of the opening 13 welded to the main girder 2 A protruding portion 5C having a larger thickness at the end on the 14 side is joined to the main girder 2 . Except for the above, this embodiment is the same as the first embodiment. It should be noted that the thickness of the end on the side of the opening 14 that protrudes upward is larger than the thickness of the end on the side of the opening 13 welded to the main girder 2 of this embodiment. The configuration of 5C may be applied to the above second embodiment.

In this embodiment, the protruding portion 5C has a thickness of the end on the side of the opening 14 that protrudes upward from the thickness of the end on the side of the opening 13 welded to the main girder 2. Since the main girder 2 and the precast floor slab 3A are thick, the strength against the force separating the main girder 2 and the precast floor slab 3A in the vertical direction can be further improved.

A fourth embodiment of the present invention will be described below. As shown in FIGS. 7A and 7B, in the fixing structure 1D of the main girder and the precast floor slab of the present embodiment, the protruding portion 5D is mainly formed at the end on the one opening 20 side. It has a tubular bottom portion 19 welded to the flange 4 of the girder 2 and a tubular extension portion 22 extending upward while fitting into the bottom portion 19 .

In the example of FIGS. 7A and 7B, both the bottom portion 19 and the extension portion 22 are tubular. The end of the extension 22 on the one opening 23 side and the other opening are longer than the length from the one opening 20 side of the bottom 19 to the other opening 21 side. The length to the end on the side of 24 is long. The outer peripheral surface of the bottom portion 19 on the side of the opening 21 and the inner peripheral surface of the extension portion 22 on the side of the opening 23 are fitted to each other. However, the shape of the bottom portion 19 and the extension portion 22 and the form of engagement between the bottom portion 19 and the extension portion 22 may be other configurations.

A method of fixing the main girder and the precast floor slab in this embodiment will be described below. In this embodiment, in the projecting portion joining step, the tubular bottom portion 19 whose end on the one side of the opening portion 20 is welded to the flange 4 of the main girder 2 and the tubular bottom portion 19 extending upward while fitting with the bottom portion 19 A projection 5D having a tubular extension 22 is joined to the main girder 2. As shown in FIG. As shown in FIGS. 8(A) and 8(B) , in the protrusion joining step, first, the end of the bottom 19 on the one opening 20 side is welded to the flange 4 of the main girder 2 . Welding of the bottom portion 19 is performed in the same manner as the welding of the projecting portion 5A to the flange 4 of the main girder 2 in the first embodiment.

As shown in FIGS. 9(A) and 9(B), after welding the end of the bottom 19 on the side of the opening 20 on one side 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. As shown in FIG. In the above description, the projecting part joining process is performed before the floor slab installing process, but either the floor slab installing process or the projecting part joining process may be performed before or after. Also, the bottom portion 19 and the extension portion 22 of this embodiment may be applied to the second embodiment or the third embodiment described above.

In this embodiment, the protruding portion 5D includes a tubular bottom portion 19 welded to the main girder 2 at one end on the side of the opening 20, and a tubular extending portion extending upward while fitting with the bottom portion 19. 22, even if the projection 5D protrudes upwardly in a long length, the bottom 19 can be easily welded to the main girder 2 after the end of the tubular bottom 19 on the one opening 20 side is easily welded to the main girder 2. The projecting portion 5D can be easily attached to the main girder 2 by fitting the tubular extension portion 22 to the main girder 2. As shown in FIG.

A 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 protruding portion 5E is composed of a plurality of tubular members whose side faces 27 are integrated with each other. is. As shown in FIGS. 10B and 11A, the projecting portion 5E is composed of two tubular members.

Each of the two tubular members includes a slit portion 28 extending along the direction from the end on the side of one opening 25 to the end on the side of the opening 26 on the other side. The two tubular members are fitted to each other through slits 28 . As shown in FIGS. 10(A), 10(B) and 11(B), two tubular members fitted to each other through slits 28 are welded together by fillet welds 29. Thereby, the projecting portion 5E is formed.

In the projecting part joining process of the fixing method of the main girder and the precast floor slab of the present embodiment, as described above, in the projecting part joining process, the plurality of tubular members having the side faces 27 integrated with each other is joined to the flange 4 of the main girder 2 . The joining of the projecting portion 5E to the flange 4 of the main girder 2 is performed in the same manner as in the first embodiment. In addition, the projecting portion 5E may be composed of three or more tubular members. Further, the structure of the projecting portion 5E, which is a plurality of tubular members in which the side surfaces 27 are integrated with each other, may be applied to the second to fourth embodiments described above.

According to this embodiment, since the projecting portion 5E is a plurality of tubular members in which the side surfaces 27 are integrated with each other, the welding length of the projecting portion 5E to the main girder 2 with respect to the lateral projected area of the projecting portion 5E can be further lengthened, it is possible to further improve the strength of the fixed structure between the main girder 2 and the precast floor slab 3A having the same number of protrusions 5E against shear force.

The strength of the anti-slip structure increases as the number of anti-slip studs increases. However, as shown in _FIG . 12(A), on the flange 4 of the main girder ₂ extending in the bridge axis direction D1 and having a width in the flange width direction D2, the headed studs 51 and 52 are adjacent to each other. It cannot be welded and placed on the flange 4 without a certain distance d that is sensible. In addition, since the anti-slippage is arranged in a limited space above the flange 4 of the main girder 2, when using the headed studs 51, 52, etc., the necessary number of headed studs 51, 52, etc. are arranged. Sometimes I can't. On the other hand, as shown in FIG. 12(B), according to the present embodiment, a plurality of tubular members are combined to be installed as a large anti-slip device, thereby saving the installation area and improving the resistance to high shear shear. can be secured.

A sixth embodiment of the present invention will be described below. As shown in FIG. 13 , in the fixing structure 1F of the main girder and the precast floor slab of this embodiment, the boundary surface 10 between the accommodating portion 8 and the filler 9 has a convex portion 30 and a concave portion 31 . In the floor slab installation process of the method of fixing the main girder and the precast floor slab of this embodiment, the precast floor slab 3B having the convex portion 30 and the concave portion 31 on the boundary surface 10 between the housing portion 8 and the filler 9 is the main girder 2. is installed on the flange 4 of the Note that the precast floor slab 3B in which the boundary surface 10 between the storage portion 8 and the filler 9 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 this embodiment, since the interface 10 between the container 8 and the filler 9 has the protrusion 30 or the recess 31, the area of the interface 10 where the container 8 and the filler 9 are in contact with each other increases. , the strength for fixing the main girder 2 and the precast floor slab 3B can be improved.

A seventh embodiment of the present invention will be described below. As shown in FIG. 14, in the fixing structure 1G for the main girder and the precast floor slab of the present embodiment, the accommodation section 8 is open to the lower surface 6 of the precast floor slab 3C, and is open to the upper surface 7 of the precast floor slab 3C. closed against. As shown in FIG. 15, the precast floor slab 3C of this embodiment is called, for example, a waffle-type floor slab.

The precast floor slab 3</b>C has a plurality of storage sections 8 partitioned by grid-like ribs 32 protruding from the lower surface 6 . In this embodiment, some of the plurality of accommodation portions 8 accommodate the projecting portion 5A. Reinforcing bars 33 are arranged along the ribs 32 in the precast floor slab 3C. The precast floor slab 3C is made of, for example, ultra high strength fiber reinforced concrete (UFC).

An example of the properties of ultra-high strength fiber reinforced concrete will be described below. This ultra-high-strength fiber-reinforced concrete is obtained by hardening a mixture containing, for example, cement, aggregate, mixing water, a chemical admixture for concrete, and reinforcing fibers. Said cements are, for example, ordinary Portland cement, high-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 of 3.0% or less, a clay lump content of 1.0% or less, and a fine particle content of 2.0%. Hereinafter, aggregates having a NaCl content of 0.02% or less are used. This aggregate was judged to be "pale" in the test result of organic impurities according to the organic impurity test method for fine aggregate specified in JISA 1105. In addition, this aggregate has a stability of 10% or less according to the stability test method for aggregates with sodium sulfate specified in JIS A 1122, and the alkali silica reactivity specified in JISA 5308 Annex 1. It is an aggregate whose division by is division A.

The above-mentioned kneading water is, for example, kneading water other than the recovered water specified in JSCE-B 101-2005. The above chemical admixture for concrete is a high performance water reducing agent specified in JISA 6204. Further, the above reinforcing fibers are fibers 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 mentioned above may be, for example, steel fibres, high strength aramid fibres, high density polyethylene fibres, or carbon fibres.

The ultra-high-strength fiber-reinforced concrete, for example, the matrix is composed of a binder consisting of Portland cement, a pozzolanic material, and an etrin guide-generating material, an aggregate having a particle size of 2.5 mm or less, water, and a water reducing agent. there is In addition, the reinforcing fibers are steel fibers with a diameter of 0.2 mm and 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, and a diameter of 0.2 mm and a length of 22 mm (manufacturing error of less than ±2 mm) and tensile strength of 2×10 ³ N/mm ² or more. % may be mixed. In addition, the characteristic values of the ultra-high-strength fiber-reinforced concrete after hardening are compression strength of 150 N/mm ² or more, crack initiation strength of 4 N/mm ² or more, tensile strength of 5 N/mm ² or more, and hydraulic conductivity of 1 × 10 ^-11 cm/. s, a chloride ion diffusion coefficient of less than 0.14 cm ² /year, and an abrasion coefficient of less than 240 mm ³ /cm ² .

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

In the floor slab installation process of the method of fixing the main girder and the precast floor slab according to the present embodiment, the housing section 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. A precast floor slab 3C is installed on the main girder 2. In the precast floor slab 3C, only at a position corresponding to the projecting portion 5A, there is a storage portion 8 that 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. You may have Further, as shown in FIG. 14 , the accommodating portion 8 may be provided with a discharge hole portion 34 for the filler 9 communicating from the accommodating portion 8 to the upper surface 7 . A precast floor slab 3C having an accommodating portion 8 that is open to the bottom surface 6 and closed to the top surface 7 of this embodiment may be applied to the second to sixth embodiments described above.

In the present embodiment, the storage section 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. The strength of the fixed structure between the main girder 2 and the precast floor slab 3C having the same number of protruding portions 5A against shear force can be further improved by the concrete portion of the precast floor slab 3C.

Further, in the present embodiment, the precast floor slab 3C has a plurality of storage portions 8 on the lower surface 6, so that the precast floor slab 3C can be made lighter. Further, in this embodiment, the precast floor slab 3C is made of ultra-high-strength fiber-reinforced concrete, so the strength of the precast floor slab 3C can be improved.

The present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art, including the embodiment described above. Moreover, it is also possible to configure a modified example using the technical matters described in the above-described embodiments.

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... protrusion, 6 ...lower surface 7...upper surface 8...accommodating portion 9...filler 10...boundary surface 11...form 12...opening 13, 14...opening 15, 16...fillet weld 17... Convex part 18... Concave part 19... Bottom part 20, 21... Opening part 22... Extension part 23, 24... Opening part 25, 26... Opening part 27... Side surface 28... Slit part 29... Corner Welded portion 30... Convex part 31... Concave part 32... Rib 33... Reinforcing bar 34... Discharge hole part 51, 52... Stud with head D1... Bridge axis direction _D2 ... _Flange width direction, d …distance.

Claims (14)

main girder and
a projecting portion projecting upward from the main girder;
a precast floor slab having an accommodation portion for accommodating the projecting portion on its lower surface;
a filling material that fills the accommodating portion that accommodates the protruding portion;
with
The projecting portion is a tubular member having one opening side end welded to the main girder, and is formed by fillet welds formed on both the outer peripheral side and the inner peripheral side of the pipe. A fixed structure between the main girder and the precast floor slab , which is welded to the main girder. main girder and
a projecting portion projecting upward from the main girder;
a precast floor slab having an accommodation portion for accommodating the projecting portion on its lower surface;
a filling material that fills the accommodating portion that accommodates the protruding portion;
with
The projecting portion is a tubular member having one opening side end welded to the main girder,
The structure for fixing the main girder and the precast floor slab, wherein the protrusions are a plurality of tubular members whose sides are integrated with each other. main girder and
a projecting portion projecting upward from the main girder;
a precast floor slab having an accommodation portion for accommodating the projecting portion on its lower surface;
a filling material that fills the accommodating portion that accommodates the protruding portion;
with
The projecting portion is a tubular member having one opening side end welded to the main girder, a tubular bottom portion having one opening side end welded to the main girder, and the bottom portion A fixing structure for the main girder and the precast floor slab, having a tubular extension that extends upward while fitting with. The structure for fixing a main girder and a precast floor slab according to any one of claims 1 to 3, wherein the projecting portion is a tubular member having a convex portion or a concave portion on a side surface. 1-, wherein the protruding portion is thicker at the end on the side of the other opening that is welded to the main girder than on the side of the other opening that is welded to the main girder. 5. Fixing structure of main girder and precast floor slab according to any one of items 4. The structure for fixing a main girder and a precast floor slab according to any one of claims 1 to 5, wherein a boundary surface between said accommodating portion and said filling material has a convex portion or a concave portion. The main girder and precast floor according to any one of claims 1 to 6, wherein the housing section 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 protrusion joining step of joining a protrusion protruding above the main girder to the main girder;
a floor slab installation step of installing a precast floor slab on the main girder;
The protrusion joined to the main girder in the protrusion joining step 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, and then the protrusion is accommodated. A filling step of filling the accommodating portion with a filling material;
with
In the projecting portion joining step, the projecting portion is joined to the main girder by welding an end of the projecting portion, which is a tubular member, on one opening side to the main girder ,
In the projecting portion joining step, fixation of the main girder and the precast floor slab is welded to the main girder by fillet welds formed on both the outer peripheral side and the inner peripheral side of the tube of the projecting portion. Method. a protrusion joining step of joining a protrusion protruding above the main girder to the main girder;
a floor slab installation step of installing a precast floor slab on the main girder;
The protrusion joined to the main girder in the protrusion joining step 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, and then the protrusion is accommodated. A filling step of filling the accommodating portion with a filling material;
with
In the projecting portion joining step, the projecting portion is joined to the main girder by welding an end of the projecting portion, which is a tubular member, on one opening side to the main girder,
A method of fixing a main girder and a precast floor slab, wherein, in the projecting portion joining step, the projecting portions, which are a plurality of tubular members whose sides are integrated with each other, are joined to the main girder. a protrusion joining step of joining a protrusion protruding above the main girder to the main girder;
a floor slab installation step of installing a precast floor slab on the main girder;
The protrusion joined to the main girder in the protrusion joining step 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, and then the protrusion is accommodated. A filling step of filling the accommodating portion with a filling material;
with
In the projecting portion joining step, the projecting portion is joined to the main girder by welding an end of the projecting portion, which is a tubular member, on one opening side to the main girder,
In the protrusion joining step,
The projecting portion is joined to the main girder, and has a tubular bottom portion whose end on one opening side is welded to the main girder, and a tubular extension portion that extends upward while fitting with the bottom portion. death,
The projecting portion is joined to the main girder by welding the end of the bottom portion on one opening side to the main girder and then fitting the extension portion to the bottom portion welded to the main girder. method of fixing the main girder and precast floor slab. The main girder and 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 projecting part joining step, the projecting part welded to the main girder and having a larger thickness at the end on the side of the other opening projecting upward than the thickness of the end on the side of the opening A method for fixing a main girder and a precast floor slab according to any one of claims 8 to 11, wherein the main girder is joined to the main girder. 13. The precast floor slab according to any one of claims 8 to 12, wherein in the floor slab installation step, the precast floor slab having a convex portion or a concave portion on a boundary surface between the filling material and the housing portion is installed on the main girder. Fixing method between main girder and precast floor slab. In the floor slab installation step, the precast floor slab is installed on the main girder, wherein 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. A method for fixing a main girder and a precast floor slab according to any one of claims 8 to 13.

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