JP7783003B2 - Bridge expansion device - Google Patents

Description

The present invention relates to a bridge expansion device that is installed in the gap between adjacent bridge girders in the bridge axis direction or between a bridge girder and an abutment.

Expansion devices are installed in the gaps between adjacent girders in the direction of the bridge axis, or between a girder and abutment, on bridges such as road bridges. These expansion devices absorb the expansion and contraction of bridge girders due to temperature changes and deformation of bridge girders caused by vehicle traffic, and are required to be highly waterproof.

For example, Patent Document 1 proposes an expansion device for road bridges with a built-in waterproofing member, as shown in Figures 9 and 10.

That is, Figures 9 and 10 are longitudinal cross-sectional views showing prior art examples 1 and 2 of road bridge expansion devices with built-in water-stopping members (hereinafter simply referred to as "expansion devices"). The expansion device 101 shown in Figure 9 has a pair of joints 102 at the opposing ends of bridge girders (not shown) that are adjacent in the bridge axis direction, sandwiching a gap S therebetween. An elastic sealing material 103 serving as a primary water-stopping member and a water-stopping member 104 serving as a secondary water-stopping member are arranged above and below the gap S on the underside of the face plates 102A of these joints 102.

Here, the elastic sealing material 103 is a block-shaped elastically deformable member made of rubber or other material, and is attached to both joints 102 so as to cover the gap δ between the pair of joints 102 from below.

The watertight member 104, located below the elastic sealing material 103, is composed of a flexible gutter portion 104A that is curved in a U-shape in vertical cross section so that its widthwise center (hereinafter, the left-right direction in Figures 9 and 10 is referred to as the "widthwise direction") bulges downward, and a flat fixing portion 104B that extends vertically downward and is connected to connecting portions 104a that are bent in an inverted U-shape outward at the upper ends of the gutter portion 104A. The watertight member 104 is installed so that it covers the gap S from below, with both fixing portions 104B attached by rivets 106 to the inner surfaces 102C of the web plates 102B that extend vertically downward from the face plate 102A of each joint 102.

With the above-described watertight structure, the elastic sealing material 103 primarily prevents rainwater and other water from penetrating into the gap S through the gap δ between a pair of fittings 102. However, there is a risk that a gap may form between the elastic sealing material 103 and the web plate 102B of the fitting 102 due to deterioration of the elastic sealing material 103. If a gap forms between the elastic sealing material 103 and the web plate 102B of the fitting 102 and water leaks from the gap and flows down the inner surface 102c of the web plate 102B, the leaking water is received by the watertight member 104 and directed into the gutter portion 104A of the watertight member 104.

The water-stopping structure has a gradient (transverse gradient) in the width direction (perpendicular to the plane of the paper in Figure 9) that is perpendicular to the bridge axis direction of the expansion device 101, and a drainage pipe (not shown) connected to the drainage pipe is provided at the end of the expansion device 101, which is located at a low position. This allows the gutter portion 104A of the water-stopping member 104 to function as a gutter that guides water leaking from the elastic sealing material 103 to the drainage pipe, and the leaking water flows through the gutter portion 104A along the gradient (transverse gradient) of the gutter portion 104A and is ultimately guided to the drainage pipe (not shown) and drained into the drainage pipe, etc.

In addition, in the expansion device 201 shown in Figure 10, elastic sealing material 203, which is a primary waterproofing member, and waterproofing member 204, which is a secondary waterproofing member, are arranged above and below the gap S. The waterproofing member 204 is composed of a gutter portion 204A with a U-shaped longitudinal cross section and flat fixing portions 204B that extend horizontally outward from the upper ends of both widthwise ends of the gutter portion 204A. The waterproofing member 204 is arranged to cover the gap between the two brackets 202C from below, with the fixing portions 204B attached by rivets 206 to the undersides 202e of brackets 202C, which protrude horizontally from the inner surface 202c of the web plate 202B of each joint 202 toward the gap S.

With the above water-stopping structure, as with the water-stopping structure shown in Figure 9, leaking water that penetrates the gap δ between the pair of fittings 202 and the gap between the elastic sealing material 203 and the web plate 202B of the fitting 202 and flows down the inner surface 202c of the web plate 202B is received by the water-stopping member 204, flows along the gradient (transverse gradient) of the gutter portion 204A of the water-stopping member 204, and is ultimately guided to a drainage pipe (not shown) located at a low gradient, such as the end of the water-stopping member 204, and is then drained into a drain pipe or the like.

Japanese Patent Application Laid-Open No. 2019-120091

However, in the expansion device 101 shown in Figure 9, a groove x is formed between the inverted U-shaped connection portion 104a formed at the upper end of each widthwise end of the water-stopping member 104 and the web plate 102B of the joint 102. Therefore, water leaking from the gap between the elastic sealing material 103 and the web plate 102B of the joint 102 and flowing down the inner surface 102c of the web plate 102B flows into the groove x. However, because the connection portion 104a of the water-stopping member 104 actually functions as a weir, the water cannot flow over the connection portion 104a of the water-stopping member 104 and into the gutter portion 104A. Instead, the water flows along the gradient (transverse gradient) through the groove x, preventing it from being guided from the gutter portion 104A to the drainage pipe. Furthermore, water that does not flow into the gutter portion 104A but flows into the groove x may leak out from the end of the water-stopping member 104, which could cause rust on the components below the end of the water-stopping member 104.

Furthermore, in the expansion device 201 shown in Figure 10, water leaking from the gap between the elastic sealing material 203 and the web plate 202B of the joint 202 and flowing down along the inner surface 202c of the web plate 202B flows along the upper surface of the bracket 202C toward the gutter portion 204A of the water-stopping member 204 if the expansion device 201 is installed in a location with no gradient in the bridge axis direction (longitudinal gradient) as shown in Figure 10(a).

However, even when the expansion device 201 is installed in a location with no gradient (longitudinal gradient) in the bridge axis direction, as shown in Figure 10(a), some water leaking through the gap between the elastic sealing material 203 and the web plate 202B of the joint 202 flows along the gradient (transverse gradient) on the horizontal upper surface of the bracket 202C, and it may not be possible to reliably guide all of the leaking water into the gutter 204A of the water-stopping member 204. Furthermore, when the expansion device 201 is installed in a location with a gradient (longitudinal gradient) in the bridge axis direction, as shown in Figure 10(b), the upper surface of the bracket 202C on the lower side (right side of Figure 10(b)) slopes upward toward the gutter 204A of the water-stopping member 204, preventing the leaking water that falls onto the upper surface of this bracket 202C from flowing into the gutter 204A of the water-stopping member 204, resulting in the same problem as described above. Furthermore, in the expansion device 201 shown in Figure 10(a), a step is formed at the boundary between the end face of the bracket 202C and the water-stopping member 204, where the side of the water-stopping member 204 protrudes from the end face of the bracket 202C toward the gap S on the widthwise center side. This step may prevent leaking water from being reliably guided to the gutter portion 204A of the water-stopping member 204.

The present invention was made in consideration of the above problems, and its purpose is to provide a bridge expansion device that can reliably guide leaking water that flows down along the inner surface of the joint's web plate into the gutter portion of the water-stopping member.

To achieve the above objectives, the present invention provides a bridge expansion device that is installed in the gap between adjacent bridge girders in the bridge axis direction or between a bridge girder and an abutment, and is equipped with a face plate, a pair of joints with web plates extending downward from the face plate, an elastically deformable gutter section that bulges downward, a water-stopping member that has flat fixing parts connected to the upper ends of both widthwise ends of the gutter section and is installed below the joints by attaching the fixing parts to each of the pair of joints, and guide means that guides water flowing down along the inner surface of the web plates of the joints toward the widthwise center of the water-stopping member.

The guide means is composed of a slope that slopes downward from the inner surface of the web of the joint toward the center of the width of the water-stopping member, and the angle of inclination of the slope is set greater than the longitudinal gradient of the bridge.

This invention ensures that water flowing down the inner surface of the joint's web can be reliably guided along the sloped surface that constitutes the guide means into the gutter portion of the water-stopping member.

Here, if the inclination angle of the slope is set greater than the longitudinal gradient of the bridge, the slope will not slope upward toward the gutter section of the water-stopping member, so water flowing down along the inner surface of the joint's web plate will be reliably guided along the slope into the gutter section of the water-stopping member.

1 is a partial perspective view of a bridge on which a bridge expansion device according to a first embodiment of the present invention is installed. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. 1 is a longitudinal cross-sectional view of a bridge expansion device according to a first embodiment of the present invention. FIG. 4 is an enlarged detailed view of a portion D in FIG. 3 . FIG. 6 is a longitudinal cross-sectional view of a bridge expansion device according to a second embodiment of the present invention. FIG. 10 is a longitudinal cross-sectional view of a bridge expansion device according to a modified example of the second embodiment of the present invention. FIG. 10 is a longitudinal cross-sectional view of a bridge expansion device according to a third embodiment of the present invention. FIG. 10 is a longitudinal cross-sectional view of a bridge expansion device according to a fourth embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a road bridge expansion device according to a first conventional example. 10A and 10B are longitudinal cross-sectional views of a road bridge expansion device according to Conventional Example 2.

The following describes an embodiment of the present invention with reference to the accompanying drawings.

First Embodiment
FIG. 1 is a partial perspective view of a bridge on which a bridge expansion device according to embodiment 1 of the present invention is installed, FIG. 2 is a cross-sectional view along line A-A in FIG. 1, FIG. 3 is a longitudinal cross-sectional view of the same bridge expansion device, and FIG. 4 is an enlarged detailed view of part D in FIG. 3.

As shown in Figures 1 and 2, the bridge expansion device 1 (hereinafter simply referred to as the "expansion device") in this embodiment is a type with built-in watertight members that is installed in the gap S between adjacent bridge girders 50 in the bridge axis direction. It is composed of a pair of joints 2 provided at the opposing ends of each bridge girder 50, elastic sealing materials 3 as primary watertight members arranged above and below the gap S, and watertight members 4 as secondary watertight members.

The pair of joints 2 are metal components with an inverted L-shaped cross section that extend in the width direction (the direction toward the front of the paper in Figure 2), perpendicular to the bridge axis. They consist of a plate-shaped front panel 2A located on the front side and a rectangular, flat web panel 2B that extends vertically downward from the front panel 2A. Multiple reinforcing anchor members (guide plates) 5 (nine on each side in the illustrated example) are attached to the back side of each joint 2 at appropriate intervals in the width direction. Furthermore, as shown in Figure 1, multiple rack-tooth-like convex portions 2a and concave portions 2b are formed alternately in the width direction on the opposing portions of the front panels 2A of both joints 2. Each convex portion 2a on one front panel 2A fits into each concave portion 2b on the other front panel 2A with a predetermined gap δ between them. Therefore, the expansion device 1 can absorb dimensional variations in the gap S by providing a predetermined gap δ between the front and rear panels 2A.

The elastic sealing material 3 is a component made of an elastically deformable material such as rubber, in the shape of a rectangular block elongated in the width direction. It is positioned at the upper end of the gap S so as to cover the gap δ between the face plates 2A of both joints 2 from below, and both side surfaces in the width direction (left and right in Figure 2) are closely adhered to the inner surface (the surface facing the gap S) 2c of the web plate 2B of each joint 2. This elastic sealing material 3 functions to prevent rainwater and other contaminants from penetrating the gap S through the gap δ between both joints 2, and also absorbs fluctuations in the gap δ caused by, for example, the expansion and contraction of the bridge girder 50 due to changes in temperature, through its own elastic deformation.

The secondary waterproofing member 4 is a long component positioned below the elastic sealing material 3 in the gap S, and is comprised of an elastically deformable gutter portion 4A that is curved in a U-shape in vertical cross section so that the center of the width bulges downward, and a fixing portion 4B with an angular C-shape in cross section that is integrally connected to connecting portions 4a formed at the upper ends of the gutter portion 4A in the width direction and extends vertically downward. The waterproofing member 4 is obtained by integrating the gutter portion 4A, made of a flexible elastic material (in this embodiment, soft polyvinyl chloride resin (soft PVC)), and the fixing portion 4B, made of an elastic material harder than the gutter portion 4A (in this embodiment, hard polyvinyl chloride resin (hard PVC)), by two-color molding. The elastic material that makes up the waterproofing member 4 can be polyvinyl chloride resin (PVC), chloroprene rubber (CR), ethylene propylene rubber (EPT), etc., but it is preferable to use a material with a JIS hardness of less than 70 for the gutter portion 4A and a material with a JIS hardness of 70 or more for the fixing portion 4B.

In this way, because the fixing portion 4B of the waterstop member 4 uses a harder elastic material than the gutter portion 4A, the rigidity of the fixing portion 4B is increased and the fixing portion 4B is not easily deformed by, for example, the weight of the gutter portion 4A or the water received by the gutter portion 4A, the expansion and contraction of the bridge girder 50 due to changes in temperature, or deformation of the bridge girder 50 due to vehicle passage. On the other hand, because the gutter portion 4A of the waterstop member 4 is made of a flexible elastic material, the gutter portion 4A can deform in response to, for example, the expansion and contraction of the bridge girder 50 due to changes in temperature and deformation of the bridge girder 50 due to vehicle passage, preventing damage to the waterstop member 4 due to the load applied.

In this embodiment, connecting portions 4a are formed by bending the upper portions of both widthwise ends of the gutter portion 4A outward in an arc shape, and the upper end of each fixing portion 4B is integrally connected to each connecting portion 4a to form the water-stopping member 4. A protrusion 4d (see Figure 4) projects from the inner surface 2c of the web panel 2B toward the gap S toward the center of the widthwise direction, and the connecting portion 4a, which has a slope 4F, is integrally molded at its tip end and protrudes integrally along the longitudinal direction (perpendicular to the plane of the paper in Figure 4). The fixing portion 4B is made of a hard, elastic material, and the presence of this protrusion 4d further increases its rigidity and maintains the angle θ (described below) of the slope 4F of the connecting portion 4a. In this embodiment, the protrusion 4d protrudes from the upper end of the fixing portion 4B at an angle θ, and the protrusion 4d also has a slope at angle θ. In this embodiment, a protrusion 4c protruding toward the gap S toward the center of the width (toward the center of the width of the gutter portion 4A) is integrally formed on the lower end (free end) of each fixed portion 4B of the water-stopping member 4 along the longitudinal direction (perpendicular to the paper surface of Figures 3 and 4). This protrusion 4c further increases the rigidity of each fixed portion 4B. In this way, the fixed portion 4B has a protrusion 4d at its upper end and a protrusion 4c at its lower end, forming an angular C-shaped cross section, thereby increasing its rigidity.

The watertight member 4 configured as described above is positioned below the elastic sealing material 3 so as to cover the gap S from below. The fixing portions 4B on both widthwise sides are tightly attached to the inner surface 2c of the web plate 2B of each joint 2 via a sealing material (not shown). Rivets 6 are inserted from the inside into circular insertion holes 4b (see Figure 4) formed in the fixing portions 4B, and then driven into circular driving holes 2d (see Figure 4) formed in the web plate 2B of each joint 2 to attach each fixing portion 4B to each web plate 2B.

In addition, in this embodiment, rivets 6 are used as fasteners for attaching the fixing portion 4B of the waterstop member 4 to the web plate 2B of each joint 2. This allows the waterstop member 4 to be fixed to the inner surface 2c of the web plate 2B simply by working from the inner surface 2c side, improving the ease of installation of the waterstop member 4. Here, for example, push rivets made of resin or drive rivets made of aluminum can be used as the rivets 6. Note that instead of rivets 6, bolts and nuts can also be used as fasteners. In the expansion device 1, for example, driving holes 2d and insertion holes 4b into which fasteners such as rivets 6 are driven are provided at equal intervals along the longitudinal direction of the waterstop member 4, and a rivet 6 is attached to each driving hole 2d and insertion hole 4b.

In the expansion device 1 configured as described above, as shown in Figures 3 and 4, the upper ends of both widthwise ends of the gutter portion 4A of the water-stopping member 4 form connecting portions 4a that are bent outward in the widthwise direction, and the upper ends of the fixing portions 4B that are perpendicular to these connecting portions 4a are integrally connected. Sloping surfaces 4F that form guide means are formed on the upper ends of both widthwise ends of the water-stopping member 4 (the connecting portions 4a of the gutter portion 4A and the parts of the fixing portions 4B that are connected to them).

As described below, the sloped surface 4F serves as a guide for directing leaking water flowing along the inner surface 2c of the web panel 2B of each joint 2 toward the widthwise center of the waterstop member 4 (the widthwise center of the gutter section 4A). It slopes downward from the inner surface 2c of the web panel 2B of each joint 2 toward the widthwise center of the waterstop member 4 by the angle θ shown in the figure (the angle from the plane direction B (Figure 4) along the plane axis of the face panel 2A, which is perpendicular to the web panel 2B facing the widthwise direction of the joint 2 (left-right direction in Figure 2)). The slope angle θ of the sloped surface 4F is set larger than the longitudinal gradient of the bridge (gradient in the bridge axis direction). For example, if the longitudinal gradient of the bridge is large, between 10% and 12%, it is desirable to set the slope angle θ of the sloped surface 4F to 7° or greater (θ≧7°). Note that Figures 3 and 4 show an example in which the expansion device 1 has almost no longitudinal gradient (0%), and the plane direction B is horizontal.

As shown in Figures 1 and 2, the expansion device 1 is installed in the gap S between adjacent bridge girders 50 in the bridge axis direction. Specifically, as shown in Figure 2, box-out sections 51a are formed at the opposing ends of the concrete deck slab 51 across the gap S. The expansion device 1 is set in these box-out sections 51a, and post-cast concrete 52 is poured into the gap between the joint 2 and anchor member 5 of the box-out section 51a. The expansion device 1 is then securely installed in the gap S between adjacent bridge girders 50, reinforced by the anchor member 5 and reinforcing bars (not shown). Finally, the installation of the expansion device 1 is completed by laying asphalt 53 to a predetermined thickness on the top surface of the deck slab 51.

Next, we will explain the waterproofing effect of the expansion device 1 according to this embodiment.

For example, during rainfall, rainwater attempts to seep into the gap S through the gap δ between a pair of joints 2 of the expansion device 1, but this rainwater intrusion is prevented by the elastic sealing material 3, which is the primary waterproofing member.

As described above, the elastic sealant 3 prevents rainwater from entering the gap S. However, if a gap develops between the elastic sealant 3 and the web plate 2B of the joint 2 due to deterioration of the elastic sealant 3's durability, rainwater will leak through this gap and, due to its own weight, flow down along the inner surface 2c of the web plate 2B of the joint 2.

When leaking water flowing down the inner surface 2c of the web plate 2B of the joint 2 reaches the water-stopping member 4, which is a secondary water-stopping member, it is reliably guided along the sloped surfaces 4F provided at the top of both widthwise ends of the water-stopping member 4 as guide means into the gutter portion 4A of the water-stopping member 4, ensuring that the leaking water is reliably drained without leaking out. In other words, leaking water that flows into the gutter portion 4A of the water-stopping member 4 flows down the gutter portion 4A along its slope and is ultimately drained into a drain pipe (not shown) or other drainage conduit.

In addition, in this embodiment, the inclination angle θ of the slope 4F, which serves as the guide means, is set to a value greater than the longitudinal gradient of the bridge, so the slope 4F does not slope upward toward the gutter portion 4A of the water-stopping member 4. As a result, leaking water flowing down the inner surface 2c of the web plate 2B of the joint 2 is reliably guided along the slope 4F to the gutter portion 4A of the water-stopping member 4.

<Second Embodiment>
Next, a second embodiment of the present invention will be described below with reference to FIG.

Figure 5 is a longitudinal cross-sectional view of a bridge expansion device according to embodiment 2 of the present invention. In this figure, the same elements as those shown in Figures 3 and 4 are designated by the same reference numerals, and further explanation of these elements will be omitted below.

In the expansion device 11 according to this embodiment, oblique brackets 2C are integrally provided on the inner surface 2c of the web plates 2B of each of the pair of joints 2, protruding toward the gap S. The fixing portion 4B of the watertight member 4, which serves as a secondary watertight member, is attached to the underside 2e of each bracket 2C with a rivet 6.

The upper surface of each bracket 2C forms a slope 2F that slopes downward at the angle θ shown in the figure from the inner surface 2c of the web plate 2B of each joint 2 toward the widthwise center of the water-stopping member 4 (the widthwise center of the gutter section 4A). This slope 2F constitutes a guide means for guiding leaking water flowing down along the inner surface 2c of the web plate 2B of the joint 2 toward the widthwise center of the water-stopping member 4 (the widthwise center of the gutter section 4A). Here, the inclination angle θ of the slope (upper surface) 2F of each bracket 2C is set to a value greater than the longitudinal gradient of the bridge for the reasons explained in the first embodiment above.

In this embodiment, the secondary water-stopping member 4 is comprised of an elastically deformable gutter section 4A that is curved in a U-shape in vertical cross section so that the widthwise center bulges downward, and flat fixing sections 4B that extend widthwise outward from connecting sections 4a formed at the upper ends of both widthwise ends of the gutter section 4A. The water-stopping member 4 is positioned below the elastic sealing material 3 so as to cover the gap S from below by attaching each fixing section 4B to the underside 2e of each bracket 2C by driving rivets 6 that pass through the insertion holes 4b (see Figure 4) of the fixing sections 4B from below into the driving holes 2d of the bracket 2C of each joint 2, with the fixing sections 4B on both widthwise sides in close contact with the underside 2e of each bracket 2C via a sealant (not shown). In this embodiment, the water-stopping member 4 is also obtained by integrating a gutter portion 4A made of soft PVC with a fixing portion 4B made of hard PVC that is harder than the gutter portion 4A through two-color molding. A downward-projecting protrusion 4d is integrally formed on the end of the fixing portion 4B of the water-stopping member 4 along the longitudinal direction (the direction perpendicular to the plane of the paper in Figure 5), and a connecting portion 4a extending vertically is integrally molded at the lower end of the protrusion 4d.

As shown in Figure 5, the protrusion 4d protrudes downward from the underside 2e of the bracket 2C, with the side of the protrusion 4d following the end face of the bracket 2C, and the side of the protrusion 4d does not protrude from the end face of the bracket 2C toward the gap S toward the center of the width. Because the protrusion 4d does not protrude from the end face of the bracket 2C toward the gap S toward the center of the width, there is no step at the boundary with the end face of the bracket 2C, and leaking water can be reliably guided into the gutter portion 4A of the water-stopping member 4. In this embodiment, as shown in Figure 5, the side of the protrusion 4d and the end face of the bracket 2C are arranged approximately flush. Here, approximately flush does not simply mean that the side of the protrusion 4d and the end face of the bracket 2C are on the same physical plane, but also allows for an error of approximately ±2 to 3 mm from the end face of the bracket 2C. Furthermore, the side of the protrusion 4d and the end face of the bracket 2C do not necessarily have to be substantially flush with each other; it is sufficient that there is no step that protrudes toward the gap S on the widthwise center side at the boundary between the protrusion 4d and the end face of the bracket 2C. For example, the side of the protrusion 4d may be located outboard in the widthwise direction of the end face of the bracket 2C, with no step that protrudes toward the gap S.

Even in an expansion device 11 configured as described above, if a gap develops between the elastic sealing material 3 and the web plate 2B of the joint 2 due to factors such as deterioration in the durability of the elastic sealing material 3, rainwater will leak through this gap and flow down the inner surface 2c of the web plate 2B due to its own weight. However, this leaking water is guided along the sloped surfaces 2F of each bracket 2C that constitutes the guide means to the gutter portion 4A of the water-stopping member 4, ensuring that the leaking water is drained without leaking to the outside. In other words, the leaking water that flows into the gutter portion 4A of the water-stopping member 4 flows down the gutter portion 4A along its slope and is ultimately drained into a drainage pipe (not shown) or other similar drainage conduit.

Furthermore, in this embodiment, as in the first embodiment, the inclination angle θ of the slope 2F of the bracket 2C, which serves as the guide means, is set to be greater than the longitudinal gradient of the bridge. This prevents the slope 2F from sloping upward toward the gutter portion 4A of the water-stopping member 4, and ensures that leaking water flowing down the inner surface 2c of the web plate 2B of the joint 2 is guided reliably along the slope (upper surface) 2F of the bracket 2C to the gutter portion 4A of the water-stopping member 4.

The above effect can be achieved as long as the upper surface of each bracket 2C is a sloped surface 2F. For example, as shown in Figure 6, the underside 2e of each bracket 2C may be a flat surface along the surface direction B (see Figure 4). In this case, the fixing portion 4B of the water-stopping member 4 is attached to the underside 2e of the bracket 2C, allowing the fastener, rivet 6, to be driven into the bracket 2C from directly below with good workability. Similar to the protrusion 4d in Figure 5 described above, the side surface of the protrusion 4d shown in Figure 6 also protrudes downward from the underside 2e of the bracket 2C so as to follow the end surface of the bracket 2C, and the side surface of the protrusion 4d does not protrude from the end surface of the bracket 2C toward the gap S toward the center of the width.

<Third Embodiment>
Next, a third embodiment of the present invention will be described below with reference to FIG.

Figure 7 is a longitudinal cross-sectional view of a bridge expansion device according to embodiment 3 of the present invention. In this figure, the same elements as those shown in Figure 5 are designated by the same reference numerals, and further explanation of these elements will be omitted below.

The basic configuration of the extension device 21 according to this embodiment is the same as that of the extension device 11 according to embodiment 2 shown in Figure 5, but differs from the extension device 11 according to embodiment 2 shown in Figure 5 in that the connection portion 4a formed at the upper end of the gutter portion 4A of the watertight member 4, which is the secondary watertight member, is curved in an arc shape and bent outward in the width direction. Furthermore, the end of the fixing portion 4B extending in the width direction is integrally molded with the connection portion 4a of the gutter portion 4A.

In the expansion device 21 according to this embodiment, water leaking from the elastic sealing material 3 and flowing down the inner surface 2c of the web plate 2B of the joint 2 is guided along the sloped surfaces (upper surfaces) 2F of each bracket 2C that constitutes the guide means to the gutter portion 4A of the water-stopping member 4, ensuring that the water is drained without leaking to the outside. In other words, water that flows into the gutter portion 4A of the water-stopping member 4 flows down the gutter portion 4A along its slope and is ultimately drained into a drain pipe (not shown) or other similar drainage pipe.

Furthermore, in this embodiment, as in the first and second embodiments, the inclination angle θ of the slope 2F of the bracket 2C, which serves as the guide means, is set to be greater than the longitudinal gradient of the bridge. This prevents the slope 2F from sloping upward toward the gutter portion 4A of the water-stopping member 4. Therefore, leaking water flowing down the inner surface 2c of the web plate 2B of the joint 2 is reliably guided along the slope 2F to the gutter portion 4A of the water-stopping member 4.

In addition to the above effects, in this embodiment, the connection portions 4a formed at the upper ends of the waterstop member 4 in the width direction are curved into an arc-shaped curve. This makes it easier for the waterstop member 4 to deform (follow) the expansion and contraction in the width direction of the expansion device 21 caused by the contraction of the bridge girder. This in turn makes it possible to suppress stress concentration at the connection portions 4a, thereby improving the durability of the waterstop member 4 as a whole.

In this embodiment, too, it is sufficient that the upper surface of each bracket 2C is a sloped surface 2F. For example, as shown in Figure 6, the underside 2e of each bracket 2C may be a flat surface along the surface direction B (see Figure 4). In this case, the fixing portion 4B of the water-stopping member 4 is attached to the flat underside 2e of the bracket 2C, allowing the fastener, rivet 6, to be driven into the bracket 2C from directly below with good workability.

<Fourth Embodiment>
Next, a fourth embodiment of the present invention will be described below with reference to FIG.

Figure 8 is a longitudinal cross-sectional view of a bridge expansion device according to embodiment 4 of the present invention. In this figure, the same elements as those shown in Figures 3 to 7 are designated by the same reference numerals, and further explanation of these elements will be omitted below.

In the expansion device 31 according to this embodiment, the tip of the bracket 2D, which protrudes integrally from the inner surface 2c of the web plate 2B of each joint 2 toward the widthwise center of the gap S, is bent vertically downward, and the fixing portion 4B of the water-stopping member 4, which has a U-shaped cross section, is attached to the outer surface 2f of the bent vertical portion 2D1 with a rivet 6. Note that although the sloping upper surface of each bracket 2D and the inner surface of the vertical portion 2D1 may be connected by a surface shape such as a corner, in this embodiment, the sloping upper surface of each bracket 2D and the inner surface of the vertical portion 2D1 are smoothly connected by a curved circular arc (R-curved surface).

The upper surface of each bracket 2D forms a slope 2F that slopes downward at the angle θ shown in the figure from the inner surface 2c of the web plate 2B of the joint 2 toward the widthwise center of the water-stopping member 4 (the widthwise center of the gutter section 4A). This slope 2F constitutes a guide means for guiding leaking water flowing down along the inner surface 2c of the web plate 2B of the joint 2 toward the widthwise center of the water-stopping member 4 (the widthwise center of the gutter section 4A). Note that the inclination angle θ of the slope (upper surface) 2F of the bracket 2D is set to a value greater than the longitudinal gradient of the bridge for the reasons mentioned above.

In this embodiment, the water-stopping member 4, which serves as a secondary water-stopping member, is composed of an elastically deformable gutter portion 4A that is curved in a U-shape in vertical cross section so that the widthwise center bulges downward, and flat fixing portions 4B that extend upward integrally from the upper ends of both widthwise ends of the gutter portion 4A. A protrusion 4c is integrally formed on the upper end of each fixing portion 4B, projecting outward in the widthwise direction, to increase the rigidity of the fixing portion 4B. Note that in this embodiment as well, the water-stopping member 4 is obtained by integrating the gutter portion 4A, which is made of soft PVC, and the fixing portion 4B, which is made of hard PVC that is harder than the gutter portion 4A, by two-color molding.

In the expansion device 31 configured as described above, as with the expansion devices 1, 11, and 21 according to the first to third embodiments, water leaking from the elastic sealing material 3 and flowing down the inner surface 2c of the web plate 2B of the joint 2 is guided along the sloped surfaces 2F on the upper surfaces of each bracket 2D that constitute the guide means to the gutter portion 4A of the water-stopping member 4, ensuring that the water is drained without leaking to the outside. In other words, the leaking water that flows into the gutter portion 4A of the water-stopping member 4 flows down the gutter portion 4A along its slope and is ultimately drained into a drainage pipe or the like via a drainage pipe (not shown).

Furthermore, in this embodiment, as in the first to third embodiments, the inclination angle θ of the slope 2F on the upper surface of the bracket 2D, which serves as the guide means, is set to be greater than the longitudinal gradient of the bridge. This prevents the slope 2F from sloping upward toward the gutter portion 4A of the water-stopping member 4. As a result, leaking water flowing down the inner surface 2c of the web plate 2B of the joint 2 is reliably guided along the slope 2F to the gutter portion 4A of the water-stopping member 4.

In addition to the above effects, in this embodiment, both fixing portions 4B of the water-stopping member 4 are attached to the outer surface 2f of the vertical portion 2D1 of each bracket 2D with rivets 6. This allows the rivets 6 to be driven in a roughly horizontal direction from the outside with good workability. Furthermore, the weight of the water-stopping member 4 itself or the leaking water flowing into the gutter portion 4A of the water-stopping member 4 acts in the direction (vertically downward) that is not the direction in which the rivets 6 would come out (roughly horizontally outward), preventing the rivets 6 from coming out and ensuring that the water-stopping member 4 is securely attached to the bracket 2D.

Note that while the above description has been given of an embodiment in which the present invention is applied to an expansion device installed in the gap between adjacent bridge girders in the bridge axis direction, the present invention can also be applied to an expansion device installed in the gap between a bridge girder and an abutment.

Furthermore, the present invention is not limited to the application of the embodiments described above, and various modifications are possible within the scope of the claims and the technical concept described in the specification and drawings. For example, in the above-described embodiment, the plate-shaped surface panels 2A of the pair of joints 2 may be surface panels 2A inclined in the bridge axis direction, and the gutter portion of the water-stopping member may have a V-shaped longitudinal cross section or a box-shaped cross section with an open upper end. Furthermore, the gutter portion 4A and fixing portion 4B of the water-stopping member 4 may be integrated using a method other than two-color molding.

In addition, in the above-described embodiment, a surface plate 2A was used in which multiple rack-tooth-shaped convex portions 2a and concave portions 2b were formed alternately in the width direction. However, the present invention is not limited to this. For example, a surface plate with linear gaps rather than multiple convex portions 2a and concave portions 2b formed alternately in the width direction may be used. Furthermore, in an extension device, surface plates of various shapes may be used, such as a sliding surface plate in which a surface plate connected to one web plate is placed above a surface plate connected to the other web plate with a gap, and surface plates extending from the opposing web plates on one and the other are stacked one above the other with a gap between them.

In addition, in the above-described embodiment, for example, the driving holes 2d and insertion holes 4b into which fasteners such as rivets 6 are driven are described as being arranged at equal intervals along the longitudinal direction of the water-stopping member 4. However, the present invention is not limited to this, and the driving holes 2d and insertion holes 4b may be arranged irregularly along the longitudinal direction of the water-stopping member 4.

In addition, in the above-described embodiment, a rectangular flat web panel 2B extending vertically downward integrally from the surface panel 2A was used as the web panel extending downward from the surface panel. However, the present invention is not limited to this, and web panels of various shapes, such as a tapered (trapezoidal) shape instead of a rectangular flat shape, may also be used.

In addition, in the above-described embodiment, a rectangular block-shaped elastic sealant 3 that is elongated in the width direction is used as the elastic sealant. However, the present invention is not limited to this, and elastic sealants having various shapes, such as a trapezoidal shape, may also be used.

1, 11, 21, 31 Bridge expansion device 2 Joint 2A Joint surface plate 2B Joint web plate 2C, 2D Joint bracket 2D1 Bracket vertical portion 2F, 4F Slope (guide means)
2a Convex portion of joint 2b Concave portion of joint 2c Inner surface of web plate 2d Drive hole in web plate 2e Underside of bracket 2f Outer surface of vertical portion of bracket 3 Elastic sealing material 4 Water-stopping member 4A Gutter portion of water-stopping member 4B Fixing portion of water-stopping member 4a Connection portion of water-stopping member 4b Insertion hole of water-stopping member 4c Projection of water-stopping member 5 Anchor member 6 Rivet 50 Bridge girder S Joint gap δ Gap between joints θ Inclination angle of slope

Claims (6)

A bridge expansion device installed in the gap between adjacent bridge girders in the bridge axis direction or between a bridge girder and an abutment,
a pair of joints each including a surface plate and a web extending downward from the surface plate;
a water-stopping member including a gutter portion that is elastically deformable and bulges downward, and flat fixing portions connected to upper portions of both ends of the gutter portion in the width direction, the fixing portions being attached to the pair of joints, respectively, thereby being installed below the joints;
a guide means for guiding water flowing down along the inner surface of the web of the joint toward the widthwise center of the water-stopping member;
Equipped with
the guide means is formed of a slope that slopes downward from the inner surface of the web plate of the joint toward the center of the water-stopping member in the width direction, and the slope angle is set to be larger than the longitudinal gradient of the bridge,
upper portions of both widthwise ends of the gutter portion of the water-stopping member form connecting portions bent outward in the widthwise direction, the fixing portions perpendicular to the connecting portions are connected, and the fixing portions are attached to the inner surface of the web plate of the joint, and the slopes are formed at the upper portions of both widthwise ends of the water-stopping member,
The water-stopping member is formed by integrating the gutter portion made of a flexible elastic material with the fixing portion made of an elastic material harder than the gutter portion, and the upper end of the fixing portion has a protrusion that protrudes from the inner surface of the web plate toward the center in the width direction and along the longitudinal direction, and the connecting portion having the slope is integrally molded at the tip end of the protrusion.
Expansion device for bridges. A bridge expansion device installed in the gap between adjacent bridge girders in the bridge axis direction or between a bridge girder and an abutment,
a pair of joints each including a surface plate and a web extending downward from the surface plate;
a water-stopping member including a gutter portion that is elastically deformable and bulges downward, and flat fixing portions connected to upper portions of both ends of the gutter portion in the width direction, the fixing portions being attached to the pair of joints, respectively, thereby being installed below the joints;
a guide means for guiding water flowing down along the inner surface of the web of the joint toward the widthwise center of the water-stopping member;
Equipped with
the guide means is formed of a slope that slopes downward from the inner surface of the web plate of the joint toward the center of the water-stopping member in the width direction, and the slope angle is set to be larger than the longitudinal gradient of the bridge,
The fixing portion of the water-stopping member is attached to a rectangular flat bracket that is long in a direction perpendicular to the bridge axis direction and that is protruded from the inner surface of the web plate of the joint, and the upper surface of the bracket is the inclined surface,
The fixing portion of the water-stopping member extends linearly outward in the width direction from a connecting portion formed at an upper end of the gutter portion of the water-stopping member, and is attached to a lower surface of the bracket of the joint.
Expansion device for bridges. 3. The bridge expansion and contraction device according to claim 2 , wherein the connecting portion formed at the upper end of the gutter portion of the water-stopping member is curved in the shape of a circular arc. The bridge expansion and contraction device according to any one of claims 1 to 3 , wherein the water-stopping member is an integral unit of the gutter portion made of a flexible elastic material and the fixing portion made of an elastic material harder than the gutter portion. 5. A bridge expansion and contraction device according to claim 4 , wherein a projection is integrally formed on the free end of said fixed portion along the longitudinal direction. The bridge expansion device according to any one of claims 1 to 5 , wherein the fixing portion is attached to the joint by a rivet.