JP2023043201A - Slab girder bridge construction method - Google Patents

Abstract

To provide a slab girder bridge construction method using rectangular slabs (rectangular precast slabs).SOLUTION: A plurality of rectangular plates (3, 4, 5) having a plurality of distributing muscles (7) arranged side by side in a long-side direction in a state in which ends with truncated conical protrusions (6) formed on the tips protrude in a width direction, and having a plurality of longitudinal bars (8) extending in the long-side direction and arranged side by side in the width direction to resist bending, are erected side by side at intervals in a direction perpendicular to the bridge axis with the long-sides facing the bridge axis direction on abutments (1, 2) spaced apart in the bridge axis direction. A filling component is filled in a space (10) opened perpendicular to the bridge axis and hardened.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for constructing a slab girder bridge using rectangular precast slabs (hereinafter referred to as "rectangular slabs").

The method of arranging multiple rectangular plates side by side to construct a bridge floor slab is widely used, but in this method, the connecting parts of multiple rectangular plates often pose construction and structural problems. Therefore, various proposals have been made regarding methods for connecting rectangular plates.

For example, in Japanese Patent Laid-Open No. 2012-225144, by providing a joint end portion in which a plurality of recesses and protrusions of a specific shape are formed in a rectangular plate, structural weaknesses are compensated and the amount of filler material is reduced. A method is disclosed.

Japanese Unexamined Patent Application Publication No. 2012-225144

Conventional rectangular plates were built on the premise that they would be placed side by side in the direction perpendicular to the bridge axis and installed on the bridge girders extending in the direction of the bridge axis. Therefore, it could not be used for slab girder bridges where floor slabs are constructed on abutments without providing bridge girders.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for constructing a slab girder bridge using rectangular slabs.

In the method for constructing a slab girder bridge according to the present invention, a plurality of distributing bars are arranged side by side in the long side direction with the ends having truncated conical projections formed at the tips protruding in the width direction, and the long side direction A plurality of rectangular plates having a plurality of main reinforcements arranged side by side in the width direction and resisting bending are placed on abutments spaced apart in the direction of the bridge axis, and the long sides are arranged in the direction of the axis of the bridge. They are erected side by side with a gap in the direction perpendicular to the bridge axis, and the filling material is filled in the gap opened in the direction perpendicular to the bridge axis and hardened.

Before filling with the filling member, an epoxy-based adhesion adhesive having an adhesion strength of 3.0 N/mm2 or ^more is applied to the surface of the rectangular plate facing the space provided in the direction perpendicular to the bridge axis. may

Protrusions extending in the width direction of the rectangular plates are provided in the vicinity of the lower edges of the surfaces of the rectangular plates facing the intervals provided in the direction perpendicular to the bridge axis, and the protruding walls of the adjacent rectangular plates abut each other. The lower openings of the interspaces provided in the transverse way may be closed.

According to the present invention, the strength due to the bearing area of the truncated cone-shaped projection formed at the tip of the distributing muscles arranged side by side in the long side direction of the rectangular plate with the ends protruding in the width direction of the rectangular plate girder. and the strength of attachment of the joint length, the adjacent rectangular plates are strongly integrated. A plurality of integrated rectangular slabs can be treated as slab girders of a slab girder bridge. In other words, it becomes possible to construct a girder bridge.

In addition, before filling the space provided in the direction perpendicular to the bridge axis with a plurality of rectangular plates installed side by side at intervals in the direction perpendicular to the bridge axis, the rectangular plates are installed in the direction perpendicular to the bridge axis before filling the space. By applying an epoxy-based adhesive with an adhesive strength of 3.0 N/mm ² or more to the surface facing the space, the rectangular plate and the filling member can be more firmly integrated. , the permeation of rainwater to the connecting portion of the rectangular plate can be suppressed, and the durability as a plate girder can be improved.

Furthermore, protruded walls extending in the width direction of the rectangular plates are provided in the vicinity of the lower edges of the surfaces of the rectangular plates facing the intervals provided in the direction perpendicular to the bridge axis. If the opening on the lower side of the space provided in the right angle method can be closed, it will be possible to shorten the construction period for constructing the plate girder bridge by saving labor and shortening the process of filling the filling material. .

FIG. 4 is a perspective view showing a state in which a plurality of rectangular plates are installed on an abutment; The protrusion formed in the edge part of the distributing muscle is shown, (a) is the figure seen from the side surface side, (b) is the figure seen from the top surface side. It is the figure which looked at the filling space|interval from the end surface side of the bridge axis direction. It is the figure which looked at the stuffing space|interval in other embodiment from the end surface side of the bridge axis direction.

Embodiments of the present invention will be described with reference to FIGS. 1 to 3, some parts are exaggerated for convenience of explanation in order to facilitate understanding of the present invention, and the relative dimensions between parts are not accurate.

The length in the span direction of the slab girder bridge constructed in this embodiment, that is, the bridge length is assumed to be 2.0 to 6.0 m, and the abutments 1 and 2 are spaced apart by 0.2 m or more in the axial direction. is set up. On the abutments 1 and 2, three rectangular plates 3, 4, and 5 are arranged with the long sides facing the direction of the bridge axis, and are spaced in the direction perpendicular to the bridge axis (hereinafter referred to as "stuffing interval 10"). are erected side by side.

The rectangular slabs 3, 4, 5 are manufactured at a site different from the site where the slab girder bridge is constructed, and are extended in the long side direction with the ends having truncated conical projections 6 formed at the tips protruding in the width direction. It has a plurality of distributing reinforcements 7 arranged side by side and a plurality of main reinforcements 8 arranged side by side in the longitudinal direction and in the width direction to resist bending. The ends of the distributing bars 7 protrude in both width directions in the rectangular plate 4 placed in the center in the direction perpendicular to the bridge axis, and the ends of the rectangular plates 3 and 5 placed on both sides in the direction perpendicular to the bridge axis It protrudes only in the direction facing the rectangular plate 4 arranged in the .

For the distributing bars 7 and the main bars 8, known reinforcing bar materials used for precast plates can be used, but deformed steel bars are preferred.

As shown in FIG. 2, the diameter of the bottom surface of the projection 6 is larger than the diameter of the force-distributing bar 7, and the portion 6a of the bottom surface protruding in the radial direction of the force-distributing bar 7 serves as a bearing surface. . By receiving the load of the truncated cone region R surrounded by the virtual curved surface S that spreads from the edge of the bottom surface of the projection 6 at an angle of 45 degrees with respect to the axis of the force distributing muscle 7, strength due to the bearing area is developed. It's becoming

Sufficient connection strength is obtained when precast plates are connected by alternately arranging reinforcing bars protruding from both side surfaces of adjacent precast plates and filling the gaps between the precast plates with filler members and hardening them. For this purpose, the length dimension of the reinforcing bar protruding from the side surface of the precast plate must be about 30 times the diameter of the reinforcing bar. On the other hand, the force distributing bar 7 with the protrusion 6 formed at the tip has a structure that is difficult to come off in proportion to the bearing pressure area provided by the protrusion 6, and even when the length of protrusion from the rectangular plates 3, 4, 5 is short. Even so, the strength necessary for connecting the rectangular plates 3, 4, 5 is developed. Therefore, it can be applied to slab girder bridges where the space between adjacent rectangular slabs in the direction perpendicular to the bridge axis is small.

The protrusions 6 can be formed by crushing the ends of the reinforcing bars forming the force distribution bars 7 with pressure. Other known methods may be employed to form the protrusions 6, but the structure in which the reinforcing bars serving as the force distributing bars 7 and another member serving as the protrusions 6 are integrated by screwing is the rectangular plate 3, It is not suitable because the strength required for linking 4 and 5 cannot be expressed.

The distributing bars 7 are arranged in two stages in the thickness direction of the rectangular plates 3, 4, 5, and the projections 6 are formed only on the distributing bars 7 arranged in the lower row when the rectangular plates 3, 4, 5 are installed. It is The force distributing muscles 7 protruding from each of the adjacent rectangular plates 3, 4 and the rectangular plates 4, 5 are arranged alternately. That is, the distributing muscles 7 projecting from the rectangular plate 4 arranged in the center and the distributing muscles 7 projecting from the rectangular plate 3 or the rectangular plate 5 arranged adjacently are arranged alternately.

In addition, the projections 6 are arranged at equal intervals along the rectangular plates 3, 4, 5 on both sides of the spacing 10, and on the opposite side of the spacing 10. 5 are arranged in a positional relationship in which they do not overlap in the width direction. The truncated conical region R, which develops strength due to the bearing pressure area of the protrusions 6 arranged on the opposite side of the interstitial spacing 10, is provided with an overlapping portion. In addition, it is preferable that the ratio of the overlapping portion of the truncated cone region R is about one-third of the entire truncated cone region R.

The arrangement intervals of the rectangular plates 3, 4, and 5 of the distributing bars 7 in the longitudinal direction should be appropriate dimensions according to the installation situation, considering the design load of the plate girder and the range of load on the bearing surface. However, it is preferable to set it to 250 mm or more. Moreover, it is preferable that the length dimension projected from the rectangular plates 3, 4 and 5 is 200 mm or more.

The interval between the main reinforcing bars 8 should be set to an appropriate dimension in consideration of the design load of the slab girder. In consideration of safety, it is preferable to further arrange a tensile reinforcing member as necessary.

The interstitial space 10 is filled with the interstitial material. Then, by hardening the filling member, a stencil beam in which the three rectangular plates 3, 4 and 5 are integrated is constructed. The constructed slab girders are completed by surface finishing, but if necessary, bridge surface waterproofing and asphalt paving may be applied.

The stuffing member preferably has a post-hardening compressive strength of 40 N/mm ² or more, which hardens in a short time and can withstand the compressive force at the overlapping portion of the truncated conical regions R after hardening. Use what is A known concrete material can be used, but an early-strength concrete material or an ultra-rapid-hardening concrete is preferable. The construction time is preferably within 24 hours, although it depends on the scale, and the filling member is selected according to this construction time.

The surfaces of the rectangular plates 3, 4, and 5 facing the spacing 10 are preferably coated with an epoxy-based adhesive having an adhesive strength of 3.0 N/mm ² or more before filling with the spacing member. . As a result, the rectangular plates 3, 4, and 5 and the filling member can be more strongly integrated, and rainwater can be prevented from penetrating into the connecting portions, thereby improving the durability of the plate girders. The amount of adhesive to be applied is preferably such that a layer having a thickness of about 1.0 mm is formed.

In this embodiment, as shown in FIG. 3, the lower opening of the stuffing space 10 is closed by the mold 11 when filling the stuffing material. However, the opening on the lower side of the stuffing interval 10 may be closed by other methods. FIG. 4 shows an embodiment of another technique for closing the stuffing interval. In FIG. 4, the same reference numerals are assigned to substantially the same parts as those in the embodiment shown in FIGS. 1 to 3, and the description thereof will be omitted or simplified.

Rectangular plates 13 and 14 shown in FIG. 4 are provided with projecting walls 12 extending in the width direction in the vicinity of the lower edges of the surfaces arranged to face the other rectangular plates 3 . By abutting the protruded walls 12 of the adjacent rectangular plates 13 and 14, the lower opening of the interstitial space 10 is closed.

In the embodiment shown in FIGS. 1 to 3, three rectangular plates 3, 4, and 5 are used, but the number of rectangular plates to be used is not limited, and can be determined appropriately according to the width of the plate girder to be constructed. can. For example, if the width of the stencil to be constructed is 4 m or less, two rectangular slabs may be used. However, it is preferable that the dimension in the width direction of the rectangular plate is 2.3 m or less.

The dimensions of the rectangular plate are preferably within a range that allows transportation by truck. That is, it is preferable to set the long side dimension to 6.0 m or less and the width dimension to 2.3 m or less. Moreover, it is preferable to determine the thickness dimension in consideration of the weight of the rectangular plate. For example, when the long side dimension is 6.0 m and the width dimension is fixed at 2.0 m, the weight is 11.76 t when the thickness is 0.4 m, and the weight is 8.0 m when the thickness is 0.2 m. A rectangular plate made of 82 tons of material can be transported by a 12 tons truck.

However, it is preferable to adjust the width dimension in consideration of the width of the slab girder bridge to be constructed. For example, in the embodiment shown in FIGS. 1 to 3, the width dimension of the rectangular plates 3 and 5 arranged on both sides in the direction perpendicular to the bridge axis is 2.0, and the rectangular plate 3 arranged in the center in the direction perpendicular to the bridge axis may be 1.7 m, and the spacing 10 may be 0.2 to 0.3 m.

1, 2 Abutments 3, 4, 5, 13, 14 Rectangular Plate 6 Projection 6a Portion of Distributing Reinforcement Protruded in Radial Direction 7 Distributing Reinforcement Reinforcement 8 Main Reinforcement 10 Interstitial Space 11 Mold 12 Protruding Wall R Conical Area S Virtual curved surface

In the method for constructing a slab girder bridge according to the present invention, a plurality of distributing bars are arranged side by side in the long side direction with the ends having truncated conical projections formed at the tips protruding in the width direction, and the long side direction A plurality of rectangular precast slabs having a plurality of main reinforcements arranged side by side in the width direction to resist bending are placed on abutments spaced apart in the direction of the bridge axis, with the long sides facing the direction of the bridge axis. The gaps provided in the direction perpendicular to the bridge axis are filled with the filling material and hardened.

Before the filling of the filler member, an epoxy-based adhesive having an adhesion strength of 3.0 N/mm2 or more is applied to the surface of the precast plate facing the space provided in the direction perpendicular to the bridge axis. good too.

A projecting wall extending in the width direction of the precast plate is provided near the lower edge of the surface of the precast plate facing the space provided in the direction perpendicular to the bridge axis, and the projecting walls of the adjacent precast plates abut each other. The lower opening of the space provided in the direction perpendicular to the bridge axis may be closed.

According to the present invention, the bearing pressure area of the truncated cone-shaped protrusion formed at the tip of the distributing muscle arranged in the long side direction of the precast plate with the end projecting in the width direction of the rectangular precast plate Adjacent precast slabs are strongly integrated by the combined action of strength and bond strength of the joint length. A plurality of integrated precast slabs can be treated as stencil girders of a slab girder bridge. In other words, it becomes possible to construct a girder bridge.

In addition, before filling the spaces provided in the direction perpendicular to the bridge axis of the precast plates installed side by side at intervals in the direction perpendicular to the bridge axis, the precast plates installed in the direction perpendicular to the bridge axis By applying an epoxy-based adhesion adhesive having an adhesion strength of 3.0 N/mm ² or more to the surface facing the space, the precast plate and the filling member can be more firmly integrated. , the permeation of rainwater to the connection part of the precast plate can be suppressed, and the durability as a plate girder can be improved.

Furthermore, projecting walls extending in the width direction of the precast slabs are provided in the vicinity of the lower edges of the surfaces of the precast slabs facing the gaps provided in the direction perpendicular to the bridge axis. If the opening on the lower side of the space provided in the perpendicular direction can be closed, it is possible to shorten the construction period for constructing the plate girder bridge by saving labor and shortening the process of filling the filling material. .

Claims (3)

A plurality of force distributing muscles arranged side by side in the long side direction with the end portion having a truncated conical projection formed at the tip protruding in the width direction, and a plurality of distributing muscles extending in the long side direction and arranged side by side in the width direction for bending A plurality of rectangular plates having a plurality of resisting main rebars are placed side by side in the direction perpendicular to the bridge axis on abutments spaced apart in the direction of the bridge axis, with the long sides facing the direction of the bridge axis. A method for constructing a slab girder bridge, characterized in that the gaps provided in the bridge axis perpendicular method are filled with filler members and hardened. Before filling with the filling member, an epoxy-based adhesive with an adhesion strength of 3.0 N/mm ² or more is applied to the surface of the rectangular plate facing the space provided in the direction perpendicular to the bridge axis. The method for constructing a slab girder bridge according to claim 1. Protrusions extending in the width direction of the rectangular plates are provided in the vicinity of the lower edges of the surfaces of the rectangular plates facing the intervals provided in the direction perpendicular to the bridge axis, and the protruding walls of the adjacent rectangular plates abut each other. 3. The method of constructing a slab girder bridge according to claim 1 or 2, wherein the lower opening of the space provided in the method perpendicular to the bridge axis is closed.

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