Connection member for existing girders in bridges and joint structure with existing girders using the same

Abstract

When connecting an additional device such as a horizontal force distribution device to an existing reinforced concrete girder, the connecting member joined to the existing girder for the purpose of connecting the additional device is given the ability to transmit horizontal force between the existing girder and the girder without the need for fitting of a convex portion and a concave portion. [Solution] The connecting member 1 has a bottom plate 2 and side plates 3, 3 that face the bottom surface 41 and both widthwise side surfaces 42, 42 of the existing girder 4, with a distance between them, and is groove-shaped so that it surrounds the existing girder 4 from below.On the surface of the bottom plate 2 facing the existing girder 4, at least a widthwise protrusion 2a is formed that faces the width direction of the existing girder 4, and on the surface of the side plate 3 facing the existing girder 4, at least a heightwise protrusion 3a is formed that faces the height direction of the existing girder 4, and in the part of the bottom plate 2 other than the widthwise protrusion 2a, a stiffening portion 2c is formed that continues in a wavy shape in at least a portion of the width direction of the bottom plate 2 when the bottom plate 2 is viewed in the longitudinal direction.

Description

[Technical Field]

[0001] The present invention relates to a connecting member that is joined to an existing girder for the purpose of connecting an additional device, such as a horizontal force distribution device that limits the amount of relative movement of an existing reinforced concrete girder, which is the superstructure, to a substructure such as a bridge pier, and to a joining structure with the existing girder using the same. [Background technology]

[0002] When connecting additional devices such as horizontal force distribution devices (displacement restriction devices) and bridge collapse prevention devices to existing girders of reinforced concrete construction (including steel-reinforced concrete), it becomes necessary to join connecting members (brackets) for connecting the additional devices to the existing girders. In order to minimize damage to the existing girders, the joining is mainly done by filling the gap between the connecting member and the existing girders with a filler such as mortar (see Patent Documents 1 to 3).

[0003] When joining a connecting member to an existing girder using filler, it is necessary to chip away the concrete from at least both sides of the existing girder in the width direction in order to ensure a degree of unity between the existing girder and the connecting member that allows for the transmission of horizontal forces, mainly in the bridge axis direction (Patent Documents 1 to 3). In this case, in order to join the connecting member without impairing the strength of the existing girder, the depth of the concrete chipped away is limited to a level that does not expose the reinforcing bars.

[0004] In Patent Documents 1 and 3, a recess is formed on the surface of the side or the side and bottom of the existing concrete girder, while a protrusion that fits into the recess is provided on the concrete surface (existing girder) side of the connecting steel member, so that when the connecting member is joined to the existing girder, the horizontal force is transmitted between the steel member and the concrete by a support pressure (corresponding to the projected area in the direction of the horizontal force) acting on the side of the protrusion and recess.

[0005] In Patent Document 2, the side of the existing girder is cut into a wedge shape, while the inner surface of the connecting member on the existing girder side is formed into a shape that fits into the wedge shape (Claim 4, paragraphs 0051-0062, Figures 11-13), creating a structure that utilizes an inclined surface to transmit horizontal forces between the connecting member and the existing girder. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2009-19493 A (Claim 1, paragraphs 0008 to 0034, Figures 1 to 14) [Patent Document 2] JP 2013-127197 A (Claim 4, paragraphs 0051 to 0062, Figures 11 to 13) [Patent Document 3] JP 2015-175140 A (Claim 1, paragraphs 0017 to 0036, Figures 1 to 10) Summary of the Invention [Problem to be solved by the invention]

[0007] In Patent Documents 1 and 3, horizontal forces are transmitted between the connecting member and the existing girder by means of bearing pressure in the direction of horizontal force action and adhesive force by fitting a convex portion into a concave portion while filling the concave portion with a filler such as an adhesive. However, since fitting the convex portion into the concave portion requires high-precision cutting of the concrete, when forming multiple convex portions, even a slight error in the position where the concave portions are formed in the concrete may result in insufficient fitting of the convex portions into the concave portions, and may also result in insufficient adhesive force if no gaps are secured around the convex portions.

[0008] In Patent Document 2, the side of the existing girder needs to be chipped into a wedge shape to fit the inner surface of the connecting member, so high-precision cutting technology is required.If the cutting is not accurate, the expected force may not be transmitted.

[0009] In light of the above background, the present invention proposes a connecting member that allows horizontal forces to be transmitted between existing girders without the need for fitting of convex and concave portions, and a joining structure using the same with existing girders. [Means for solving the problem]

[0010] The connecting member for existing girders in the bridge of the invention described in claim 1 is an additional device additionally installed on the existing reinforced concrete girders of the bridge. is joined to the existing girder to connect it to the existing girder. a connecting member, The bottom surface and width direction of the existing girder on both sides of The girder has a bottom plate and a side plate facing each other and spaced apart from each other, and has a groove shape that surrounds the existing girder from below, At least a width direction protrusion facing the width direction of the existing girder is formed on the surface of the bottom plate facing the existing girder, and at least a height direction protrusion facing the height direction of the existing girder is formed on the surface of the side plate facing the existing girder, A constituent element of the present invention is that a stiffening portion having a wave-shaped configuration that is continuous in at least a portion of the width direction of the bottom plate when viewed in the longitudinal direction is formed in a portion of the bottom plate other than the width direction protrusion.

[0011] "Reinforced concrete construction" includes precast concrete, and in some cases prestressed concrete structures. The cross-sectional shape of the existing girder is not particularly important, but because the connecting member 1 joined to the existing girder 4 has a grooved shape as shown in Figure 8-(a), a T-shaped or I-shaped cross section is generally suitable for the existing girder 4, as shown in Figure 8-(b). "Additional devices additionally installed on the existing girder" primarily refer to the horizontal force distribution devices (displacement limiting devices) and bridge fall prevention devices mentioned above, but are not limited to these devices as long as they are connected to the existing girder 4 after the fact.

[0012] "Bottom surface and width direction of existing girder on both sides of "Having a bottom plate and side plates facing the side surfaces and spaced apart from each other" means that, as shown in Figure 9-(a), a distance is maintained between the top surface (inner peripheral surface) of the bottom plate 2 of the connecting member 1 and the bottom surface 41 of the existing girder 4, and a distance is maintained between the side surface (inner peripheral surface) of the side plate 3 of the connecting member 1 facing the existing girder 4 and the side surface 42 in the width direction of the existing girder 4. The connecting member 1 has a groove-shaped configuration consisting of the side plates 42, 42 facing each other in the width direction of the existing girder 4 and the bottom plate 41 that connects them. "Groove-shaped" means "a groove-shaped cross-sectional shape."

[0013] "At least widthwise protrusions facing the width direction of the existing girder are formed on the surface of the bottom plate facing the existing girder" means that widthwise protrusions 2a that are continuous at least in the width direction (horizontal direction) of the existing girder 4 are formed on the top surface (surface facing the existing girder 4) of the bottom plate 2 of the connecting member 1 as shown in Figure 1-(b) and Figure 3-(a). The widthwise protrusions 2a do not necessarily have to be continuous over the entire width direction of the bottom plate 2, and at least a portion may be continuous and formed intermittently.

[0014] The phrase "at least widthwise protrusions are formed" means that protrusions other than the widthwise protrusions 2a, such as the axial protrusions 2b described below, and other portions may be formed on the bottom plate 2 of the connecting member 1. A plurality of widthwise protrusions 2a are arranged at appropriate intervals in the length direction of the bottom plate 2 (axial direction of the connecting member 1).

[0015] The widthwise protrusions 2a of the bottom plate 2 are embedded in mortar, concrete, adhesive or other filler 5 that is filled in the gap between the bottom surface 41 of the existing girder 4 (claim 6), and the horizontal force acting on the connecting member 1 from the additional device 7 in the axial direction (bridge axis direction) of the existing girder 4 is transmitted to the existing girder 4 by the adhesive force generated between the bottom plate 2a and the filler 5 and the support pressure equivalent to the projected area of ​​the widthwise protrusions 2a in the direction of horizontal force action.

[0016] The widthwise protrusions 2a of the bottom plate 2 are formed continuously in the width direction of the existing girder 4 (connecting member 1), and serve as resistance elements against bending moments around the axis oriented in the lengthwise direction of the bottom plate 2 (the axial direction of the existing girder 4), thereby ensuring or increasing the bending rigidity around the axis oriented in the lengthwise direction of the bottom plate 2 itself. The "lengthwise direction of the bottom plate 2" is also the axial direction of the existing girder 4 (connecting member 1).

[0017] "At least a height-direction protrusion facing the height direction of the existing girder is formed on the surface of the side plate facing the existing girder" means that a height-direction protrusion 3a that continues in the height direction (vertical direction) of the existing girder 4 is formed on the surface (inner peripheral surface) of the side plate 3 of the connecting member 1 facing the existing girder 4. The height-direction protrusion 3a does not necessarily have to be continuous over the entire height direction of the side plate 3, and at least a portion may be continuous and formed intermittently. "At least a height-direction protrusion is formed" means that the side plate 3 of the connecting member 1 may have protrusions or other parts other than the height-direction protrusion 3a.

[0018] The height direction protrusions 3a of the side plates 3 are embedded in the filler material 5 that fills the gaps secured between them and the side surfaces 42 in the width direction of the existing girder 4 (claim 6), and the horizontal force in the axial direction (bridge axis direction) of the existing girder 4 that acts on the connecting member 1 from the additional device 7 is transmitted to the existing girder 4 by the adhesive force generated between them and the filler material 5 and the support pressure equivalent to the projected area of ​​the height direction protrusions 3a in the direction of horizontal force action. Furthermore, by being formed continuously in the height direction of the side plates 3, the height direction protrusions 3a become a resistance element against bending moments around the axis oriented in the length direction of the side plates 3, and therefore also serve to ensure or increase the bending rigidity of the side plates 3 themselves around the axis oriented in the length direction.

[0019] "When the bottom plate is viewed in the longitudinal direction, stiffening portions are formed in the portions other than the widthwise protrusions of the bottom plate, at least a portion of which is continuous in a wavy shape in the width direction of the bottom plate" means that when the bottom plate 2 is viewed in the longitudinal direction as shown in Figures 1-(b) and 3-(a), stiffening portions 2c are formed in the portions other than the widthwise protrusions 2a arranged at intervals in the longitudinal direction (axial direction) of the bottom plate 2. The "wavy shape" can be a zigzag cross-sectional shape as shown in the figure, or a cross-sectional shape in which curves are alternately continuous in an uneven manner.

[0020] The phrase "at least partially continuous" refers to cases where the stiffening portions 2c are formed in a continuous wave shape in the width direction of the bottom plate 2, and cases where the stiffening portions 2c are formed in a wave shape in the width direction of the bottom plate 2 while being partially continuous in the wave shape and intermittently formed in the width direction of the bottom plate 2. The stiffening portions 2c form a wave shape in the width direction of the bottom plate 2, and are formed at multiple locations spaced apart in the length direction of the bottom plate 2 as shown in Figure 1-(b). Because the stiffening portions 2c have a wave shape when the bottom plate 2 is viewed in the length direction, the wave shape remains continuous between adjacent width direction protrusions 2a, 2a in the length direction of the bottom plate 2.

[0021] The stiffening portion 2c continues in the longitudinal direction of the bottom plate 2 while maintaining its wave-shaped shape, and therefore serves as a resistance element against the bending moment acting on the connecting member 1 or the bottom plate 2 around the axis facing the width direction of the existing girder 4, thereby ensuring or increasing the bending rigidity of the bottom plate 2 itself around the axis facing the width direction.

[0022] As a result of the above-mentioned widthwise protrusions 2a ensuring bending rigidity around the axis facing the length of the bottom plate 2, the stiffening parts 2c ensuring bending rigidity around the axis facing the width of the bottom plate 2, and the heightwise protrusions 3a of the side plates 3 ensuring rigidity of the side plates 3, the bending rigidity of the bottom plate 2 and side plates 3 increases, making it possible to reduce the plate thickness of each part (each element) that makes up the bottom plate 2 and side plates 3. As a result, it becomes possible to reduce the weight of the connecting member 1 itself, and the burden on the existing girder 4 that comes with joining the connecting member 1 is also reduced. "Each part that makes up the bottom plate 2 and side plates 3" refers to the plate elements including the widthwise protrusions 2a, stiffening parts 2c, and heightwise protrusions 3a.

[0023] In addition, the widthwise protrusion 2a ensures bending rigidity around an axis facing the lengthwise direction of the bottom plate 2, and the stiffening portion 2c ensures bending rigidity around an axis facing the widthwise direction of the bottom plate 2, thereby providing stability against deformation of the bottom plate 2 and making it easier to transmit horizontal forces between the bottom plate 2 of the connecting member 1 and the bottom surface 41 of the existing girder 4.

[0024] Additionally, because the stiffening portion 2c is corrugated, the adhesion area with the filler 5 filled between the bottom plate 2 and the bottom surface 41 of the existing girder 4 is larger than when the bottom plate 2 is a flat or nearly flat plate, and therefore the adhesion force between the bottom plate 2 and the filler 5 increases, improving the effect of transmitting horizontal forces in the axial direction (bridge axis direction) of the existing girder 4 as well as in the width direction (perpendicular to the bridge axis). In particular, because the stiffening portion 2c is continuously formed in a corrugated shape in the width direction of the bottom plate 2, the effect of transmitting horizontal forces by bearing pressure acting in the width direction of the existing girder 4 is also improved.

[0025] In addition, as described above, the height-direction protrusions 3a of the side panels 3 also exert the effect of transmitting horizontal forces in the axial direction of the existing girder 4 between them and the side surfaces 42 of the existing girder 4, so the effect of transmitting horizontal forces in the axial direction of the existing girder 4 is increased compared to when the side panels 3 are flat or nearly flat panels.

[0026] Furthermore, the widthwise protrusions 2a and stiffening parts 2c of the bottom plate 2, and the heightwise protrusions 3a of the side plates, provide an effect of transmitting horizontal forces in the axial direction between the existing girder 4, eliminating the problem of insufficient adhesive strength resulting from insufficient filling of the filler due to insufficient voids in the recess when the protrusion is fitted, as occurs when fitting a protrusion into a recess. As a result, it becomes possible to "transmit horizontal forces between the connecting member 1 and the existing girder 4 without the need to fit the protrusion into the recess."

[0027] As mentioned above, the widthwise protrusions 2a of the bottom plate 2 mainly function to ensure bending rigidity around an axis oriented in the lengthwise direction of the bottom plate 2, but in particular, if the widthwise protrusions 2a are formed not only on the surface of the stiffening part 2c facing the existing girder 4 (front side) but also on both the surface of the stiffening part 2c facing the existing girder 4 (front side) and the opposite surface (back side) as shown in Figure 3-(a) (claim 2), bending rigidity elements are added to the bottom (lower surface) side as well as the upper surface side of the bottom plate 2, further increasing bending rigidity around an axis oriented in the lengthwise direction of the bottom plate 2 itself. As a result, stability against bending moments around an axis oriented in the lengthwise direction of the bottom plate 2 itself is improved, further contributing to reducing the weight of the connecting member 1 itself and improving the horizontal force transmission effect.

[0028] Furthermore, if the widthwise protrusions 2a of the bottom plate 2 have a shape such that the lengthwise width of the bottom plate 2 gradually expands from the bottom surface 41 side of the existing girder 4 to the bottom plate 2 side as shown in Figure 2-(a) (Claim 3), the width in the axial direction of the existing girder 4 of the portion formed between the widthwise protrusions 2a, 2a of the filling material 5 filled between the bottom surface 41 of the existing girder 4 and the bottom plate 2 will gradually decrease from the existing girder 4 side to the connecting member 1 (bottom plate 2) side, thereby increasing the resistance to shear force and bending moment when the filling material 5 bears the axial horizontal force.

[0029] The filler material 5 that fills in between adjacent widthwise protrusions 2a, 2a of the bottom plate 2 has an inverted trapezoidal cross-section in which the width in the axial direction of the existing girder 4 gradually decreases from the bottom surface 41 side of the existing girder 4 to the bottom plate 2 side. When a horizontal force in the axial direction of the existing girder 4 acts on this part and a reaction force is received from the widthwise protrusions 2a, a bending moment acts on the inverted trapezoidal part, with the maximum on the bottom surface 41 side of the existing girder 4, but because the inverted trapezoidal shape is suited to the bending moment distribution, it is highly stable against bending moments. Shear forces are also resisted by the widest cross-section of the inverted trapezoid, so it is also highly stable against shear forces.

[0030] In addition, as shown in Figures 1-(b), 2 and 3-(b), if a flat portion 23 having a width greater than the width of the width-direction protrusion 2a in the length direction of the bottom plate 2 is formed toward the width direction of the existing girder 4 on the surface of the bottom plate 2 facing the existing girder 4, and a receiving portion 2d is formed on the surface of this flat portion 23 facing the existing girder 4 to support a spacer 6 that maintains the gap between it and the bottom surface 41 of the existing girder 4 (claim 4), it becomes possible to reliably ensure the distance (gap) between the bottom surface 41 of the existing girder 4 and the bottom plate 2. The receiving portion 2d may support and restrain the spacer 6.

[0031] In claim 4, the receiving portion 2d supports the spacer 6, so that the filler material 5 is filled between the connecting member 1 and the existing girder 4, and the gap between the bottom surface 41 of the existing girder 4 and the bottom plate 2 of the connecting member 1 is reliably maintained until the filler material 5 hardens, ensuring a constant gap between the two. In particular, when the receiving portion 2d restrains the spacer 6, the spacer 6 is prevented from moving due to the pressure of the filler material 5 when it is filled, ensuring the stability of the spacer 6 when it is filled with the filler material 5.

[0032] Furthermore, as shown in Figures 4-(a) and 4-(b), if the surface (inner peripheral surface) of the side plate 3 of the connecting member 1 facing the existing girder 4 is shaped so that the distance from the side surface 42 of the existing girder 4 gradually decreases from the middle in the height direction to the upper and lower parts in the height direction (claim 5), when a force including a vertical component acts on the connecting member 1 from, for example, an additional device 7, the filler 5 between the side surface 42 of the existing girder 4 and the side plate 3 will be able to easily exert resistance to the vertical force. The filler 5's ability to exert resistance to the vertical force makes it possible to ensure the stability of the connecting member 1 when joined to the existing girder 4.

[0033] "A shape in which the distance to the side surface 42 gradually decreases" refers to a shape in which, on a vertical cross section when the connecting member 1 is viewed axially, the distance between the inner surface of the side plate 3 and the side surface 42 gradually decreases from the middle part in the height direction to the upper and lower parts, and the upper and lower parts from the middle part in the height direction gradually approach the side surface 42. This shape can decrease linearly or curvedly on the vertical cross section. When the side surface 42 of the existing girder 4 forms a vertical plane, the section from the middle part to the upper part of the inner surface of the side plate 3 and the section from the middle part to the lower part are inclined toward the side surface 42.

[0034] The inner peripheral surface of the side plate 3 is shaped so that the upper and lower parts in the height direction gradually approach the side surface 42 of the existing girder 4 from the middle part, so that when a vertically downward force acts on the connecting member 1, for example, the filler material 5 between the existing girder 4 and the side plate 3 receives a downward force from the section from the middle to the top of the connecting member 1. In contrast, the trapezoidal filler material 5 that exists in the section from the middle to the top of the connecting member 1 and is sandwiched between the side plate 3 and the side surface 42 is restrained by the side plate 3 and the side surface 42, so that an upward vertical reaction force is generated from the hypotenuse of the trapezoid, and it is able to resist the downward force from the connecting member 1.

[0035] Similarly, when a vertically upward force acts on the connecting member 1 and the filler 5 receives an upward force from the section from the middle to the bottom of the connecting member 1, the filler 5, which has an inverted trapezoidal shape in the section from the middle to the bottom of the connecting member 1, generates a vertically downward reaction force from the hypotenuse of the trapezoid, and is therefore able to resist the upward force from the connecting member 1.

[0036] The connecting member 1 according to any one of claims 1 to 5 is a connecting member that is connected to the bottom surface 41 of the existing girder 4. both sides With a distance between the side surfaces 42, 42, it is placed from below the existing girder 4 as shown in Figures 8-(b) and 9-(a). both sides The side surfaces 42, 42 are respectively formed with recesses 41a, 42a to increase the adhesive force between the bottom plate 2 and the side plates 3, 3 and the existing girder 4, and the connecting member 1 is joined to the existing girder 4 by filling the filler 5 between the bottom plate 2 and the side plates 3, 3 and the existing girder 4 (claim 6).

[0037] Neither the width direction protrusion 2a, the axial direction protrusion 2b, nor the stiffening portion 2c of the bottom plate 2 of the connecting member 1 enters into the recess 41a. Neither the height direction protrusion 3a nor the axial direction protrusion 3b of the side plate 3 of the connecting member 1 enters into the recess 42a. In principle, both recesses 41a and 42a are formed deep enough to prevent both the main reinforcement and shear reinforcement bars from being exposed, in order to protect the main reinforcement and shear reinforcement bars arranged in the existing girder 4.

[0038] In this case, if the recess 41a on the bottom surface 41 of the existing girder 4 is formed in a shape such that the axial width of the existing girder 4 gradually increases from the center of the width of the existing girder 4 to both sides in the width direction as shown in Figure 7-(c) (claim 7), it will be possible to impart resistance to the filler 5 when a torsional moment in a horizontal plane acts on the filler 5 after the connecting member 1 is joined to the existing girder 4 as described below. "In a horizontal plane" refers to a plane parallel to the bottom surface 41 of the existing girder 4.

[0039] When a torsional moment in the horizontal plane acts on the filler 5 that has hardened in the recess 41a on the bottom surface 41 of the existing girder 4, the bending moment generated in the filler 5 is distributed in a triangular shape that is centered on the widthwise center of the bottom surface 41 of the existing girder 4 and increases with the distance in the width direction. A "torsional moment in the horizontal plane" can occur when there is a difference in the horizontal forces acting on the side plates 3, 3 on both sides of the connecting member 1.

[0040] For this reason, by forming the shape of the recess 41a so that the width of the existing girder 4 in the axial direction gradually increases from the center side of the width direction of the existing girder 4 to both sides in the width direction, it is possible to make the bending stress generated in the filler 5 uniform regardless of the distance from the center of the width direction of the existing girder 4. As a result, as the distance from the center in the width direction increases, it does not become a weak point against the bending moment caused by the torsional moment. [Effects of the Invention]

[0041] Since widthwise protrusions facing the width direction of the bottom plate are formed on the surface of the bottom plate of the connecting member facing the existing girder, and stiffening parts that are continuous and wavy in the width direction of the bottom plate are formed in the parts of the bottom plate other than the widthwise protrusions, it is possible to ensure bending rigidity against bending moments acting on the connecting member around an axis facing the axial direction of the existing girder and around an axis facing the width direction of the existing girder.In addition, heightwise protrusions facing the height direction of the existing girder are formed on the surface of the side plate facing the existing girder, so bending rigidity against bending moments acting on the side plate around an axis facing the length direction of the side plate can also be ensured.

[0042] This increase in bending rigidity of the bottom plate and side plate allows the thickness of each part (each element) that makes up the bottom plate and side plate to be reduced, which in turn makes it possible to make the connecting member itself lighter and also reduces the burden on the existing girder associated with joining the connecting member.

[0043] Furthermore, by giving the stiffening section a wave-shaped configuration that continues across the width of the bottom plate, the adhesion area with the filler filled between the bottom plate and the bottom surface of the existing girder is larger than when the bottom plate is flat, which increases the adhesion force between the bottom plate and the filler, and improves the horizontal force transmission effect in both the axial direction of the existing girder (bridge axis direction) and the width direction (direction perpendicular to the bridge axis).In addition, the height-direction protrusions of the side plates exert a horizontal force transmission effect in the axial direction of the existing girder between them and the side of the existing girder, further improving the horizontal force transmission effect in the axial direction of the existing girder.

[0044] By forming the widthwise protrusions and stiffening parts of the bottom plate and the heightwise protrusions of the side plates, the effect of transmitting axial horizontal forces between the existing girder and the girder is achieved.This eliminates the problem of insufficient adhesion due to insufficient filling of the filler material caused by insufficient voids in the recess when the convex part is fitted, as is the case when fitting a convex part into a recess.Therefore, it is possible to transmit horizontal forces between the connecting member and the existing girder without the need to fit the convex part into the recess. [Brief explanation of the drawings]

[0045] [Figure 1] (a) shows an example of a connecting member, an elevational view of the connecting member when viewed in the width direction, (b) is a plan view taken along line aa in (a), and (c) is a bottom view taken along line bb in (a). [Figure 2] (a) is a cross-sectional view taken along line cc in Figure 1-(b), (b) is a cross-sectional view taken along line dd in Figure 1-(b), and (c) is a side view taken along line ee in Figure 1-(b). [Figure 3] (a) is a cross-sectional view taken along line ff in Figure 1-(b), and (b) is a cross-sectional view taken along line gg in Figure 1-(b). [Figure 4] (a) is a side view of the connecting member shown in Figure 1 when it is combined with an existing girder with a large width, as viewed in the axial direction, and (b) is a side view of the connecting member when it is combined with an existing girder with a small width. [Figure 5] 2(a) is a perspective view showing the inner peripheral surface of the connection member shown in FIG. 1, and FIG. 2(b) is a perspective view showing the rear surface (bottom surface) of the connection member. [Figure 6] FIG. 2-(c) is a cross-sectional view taken along line hh in FIG. [Figure 7] (a) is an elevation view of the existing girder when viewed in the width direction, showing an example of forming a recess on the side of the existing girder, (b) is a side (cross-sectional) view of (a), and (c) is a bottom view showing an example of forming a recess on the bottom surface of the existing girder. [Figure 8] FIG. 10(a) is a perspective view showing another example of a connecting member, and FIG. 10(b) is a perspective view showing the connecting member shown in FIG. 10(a) joined to an existing girder. [Figure 9] (a) is a longitudinal cross-sectional view of the existing girder in the axial direction, showing the additional device connected to the connecting member that is placed below the existing girder so as to surround it from below, and is joined to the existing girder by filling the gap between the existing girder and the connecting member; (b) is a horizontal cross-sectional view of (a); and (c) is an enlarged view of the dashed line part of (b). DETAILED DESCRIPTION OF THE INVENTION

[0046] Figures 1 to 5 and Figure 8-(a) show the bottom surface 41 of the existing reinforced concrete girder 4 of the bridge and the width direction. both sides This shows an example of the manufacturing of a connecting member 1 that has a bottom plate 2 and side plates 3, 3 facing side surfaces 42, 42 with a distance between them, has a groove shape that surrounds the existing girder 4 from below, and is joined to the existing girder 4. The connecting member 1 is formed by casting.

[0047] The existing girder 4 is mainly made of prestressed concrete, and in some cases at least a portion of it is made of precast concrete. As shown in Figure 8-(b), the connecting member 1 is placed so as to surround the existing girder 4 from below, with a distance between the bottom surface 41 of the existing girder 4 and both side surfaces 42, 42, and is joined to the existing girder 4 by filling the space between the connecting member 1 and the existing girder 4 with a filler 5 such as mortar, concrete, or adhesive. An additional device 7, such as a horizontal force distribution device (displacement limiting device), which is additionally installed on the existing girder 4 as shown in Figure 9, is connected to the connecting member 1.

[0048] As the filler 5, a high-strength fiber-reinforced cementitious composite material is suitable, which has high adhesion to the concrete that is the constituent material of the existing girder 4, high self-compacting properties, and high durability. In particular, a high-strength fiber-reinforced cementitious composite material containing PVA (polyvinyl alcohol) has a design standard strength of 100 N / mm 2 It has a strength of 3.3N / mm and can be demolded after one day. 2 It has the characteristic of exhibiting high adhesive strength with concrete.

[0049] As shown in Figure 5-(a), at least width-direction protrusions 2a facing the width direction (horizontal direction) of the existing girder 4 are formed on the surface (upper surface) of the bottom plate 2 facing the existing girder 4, and at least height-direction protrusions 3a facing the height direction (vertical direction) of the existing girder 4 are formed on the surface of the side plate 3 facing the existing girder 4. Multiple height-direction protrusions 3a are arranged at intervals in the length direction (axial direction) of the connecting member 1. In the drawing, height-direction protrusions 3a are also formed on both sides of the length direction of the side plate 3, further increasing the adhesive force between the side plate 3 and the filler 5 that is filled in between the side surface 42 of the existing girder 4.

[0050] In the portions of the bottom plate 2 other than the widthwise protrusions 2a, when the bottom plate 2 is viewed in the lengthwise direction (axial direction), stiffening portions 2c are formed, at least a part of which continues in a wavy shape in the widthwise direction of the bottom plate 2. Since the stiffening portions 2c appear wavy when the bottom plate 2 is viewed in the lengthwise direction, the wavy shape is drawn in the widthwise direction of the bottom plate 2, and the wavy shape continues in the lengthwise direction of the bottom plate 2.

[0051] The width direction protrusions 2a and height direction protrusions 3a are embedded in the filler material 5, and mainly function to ensure adhesion between them and the filler material 5, and transmit the horizontal force acting in the length direction of the connecting member 1 to the existing girder 4 through the adhesion force and support pressure. The stiffening portion 2c is also embedded in the filler material 5, and functions in the same way as the two protrusions 2a, 3a, but also has the role of stiffening the bottom plate 2 against the bending moment acting on the connecting member 1 around an axis oriented in the width direction of the existing girder 4.

[0052] As shown in Figure 1-(b), the bottom plate 2 has side portions 21, 21 that connect to the side plates 3 near the side plates 3, 3, and end portions 22, 22 that connect the side portions 21, 21 in the width direction of the bottom plate 2 on both sides of the direction along the side plates 3. The "direction along the side plates 3" is the length direction (axial direction) of the connecting member 1 or the bottom plate 2, and the perpendicular direction is the width direction of the connecting member 1 or the bottom plate 2. The side portions 21, 21 and end portions 22, 22 form the edge portions (frame) of the bottom plate 2.

[0053] On the surface of the existing girder 4 side in the area surrounded by the side portions 21, 21 and the end portions 22, 22, multiple widthwise protrusions 2a are formed, arranged in the lengthwise direction of the bottom plate 2 and at least partially continuing in the widthwise direction of the bottom plate 2. Multiple axial protrusions 2b are formed, at least partially continuing in the lengthwise direction of the bottom plate 2, and arranged in the widthwise direction of the bottom plate 2. The widthwise protrusions 2a face the width direction of the existing girder 4, and the axial protrusions 2b face the axial direction of the existing girder 4, and are each formed in a stripe shape.

[0054] The widthwise protrusions 2a are formed continuously or intermittently between the side portions 21, 21, and the axial protrusions 2b are formed continuously or intermittently between the end portions 22, 22. Stiffening portions 2c are formed continuously in the length direction of the bottom plate 2 between the widthwise protrusions 2a, 2a adjacent in the length direction of the bottom plate 2. The upper surfaces of the widthwise protrusions 2a and the axial protrusions 2b may or may not be aligned as shown in Figure 1-(b).

[0055] Flat portions 23 having flat upper surfaces are formed between the side portions 21 and the adjacent axial protrusions 2b, and between adjacent axial protrusions 2b, 2b in the width direction of the bottom plate 2. Stiffening portions 2c are continuously formed in the length direction of the bottom plate 2 between the end portions 22 and the flat portions 23, between the flat portions 23 and the adjacent width direction protrusions 2a, and at least partially between adjacent width direction protrusions 2a, 2a.

[0056] As shown in Figures 1-(b) and 3-(a), the stiffening portion 2c is formed in a wave shape in the width direction of the bottom plate 2 between the side portion 21 and the adjacent axial protrusion 2b, and between the adjacent axial protrusions 2b, 2b. The stiffening portion 2c between the side portion 21 and the axial protrusion 2b, and between the adjacent axial protrusions 2b, 2b is composed of, for example, two corrugated sheets 2c1, 2c1 that intersect at an angle to each other in the width direction of the bottom plate 2, but the corrugated sheet 2c1 does not need to be flat and may be a curved sheet. When the corrugated sheet 2c1 is a curved sheet, the stiffening portion 2c has a shape in which the curved surface is continuously uneven.

[0057] As shown in Figure 3-(a), it is reasonable to form the widthwise protrusions 2a on the surface of the stiffening part 2c that faces the existing girder 4 (front side) and on the opposite surface (back side). Specifically, by forming the widthwise protrusions 2a, 2a between the front and back surfaces of the corrugated plates 2c1, 2c1 that make up the stiffening part 2c and are adjacent in the width direction of the bottom plate 2, the widthwise protrusions 2a, 2a on both sides of the bottom plate 2 become elements that resist the bending moment acting around an axis that faces the lengthwise direction of the bottom plate 2.

[0058] As described above, the connecting member 1 is joined to the existing girder 4 by the adhesive force of the filler 5 filled between the connecting member 1 and the existing girder 4, but when the bottom plate 2 is viewed in the width direction, the filler 5 filled on the bottom plate 2 is partitioned between the width direction protrusions 2a, 2a of the bottom plate 2 as shown in Figure 2-(a).

[0059] The filler 5 between the widthwise protrusions 2a, 2a transmits the longitudinal force of the bottom plate 2 acting on the connecting member 1 to the existing girder 4 through the support pressure and adhesive force of the projected area acting on the side of the widthwise protrusions 2a. When the part of the filler 5 sandwiched between the widthwise protrusions 2a, 2a transmits the support pressure, it receives a reaction force from the widthwise protrusions 2a, 2a, and a shear force and a maximum bending moment act on the part that contacts the upper end of the widthwise protrusions 2a.

[0060] This bending moment acts so as to gradually increase from the bottom of the portion sandwiched between the widthwise protrusions 2a to the portion that contacts the upper end of the widthwise protrusions 2a. For this reason, it is reasonable to form the filler 5 between the widthwise protrusions 2a in a shape that gradually expands in the length direction of the bottom plate 2 from the bottom to the portion that contacts the upper end of the widthwise protrusions 2a, as shown in Figure 2-(a). This is because the resistance to the bending moment increases compared to when the width of the bottom plate 2 in the length direction is constant.

[0061] Therefore, it is appropriate that the width of the widthwise protrusions 2a of the bottom plate 2 be shaped so that the lengthwise width of the bottom plate 2 gradually increases from the side (front surface side) of the existing girder 4 to the opposite side (back surface side). By shaping the width of the widthwise protrusions 2a of the bottom plate 2 so that the lengthwise width of the bottom plate 2 gradually increases from the side (front surface side) of the existing girder 4 to the opposite side (back surface side), the filler 5 formed between adjacent widthwise protrusions 2a, 2a in the lengthwise direction of the bottom plate 2 is formed so that it gradually increases from the bottommost part to the part that contacts the upper end of the widthwise protrusions 2a.

[0062] As shown in Figure 1-(b), a flat portion 23 with a flat upper surface is formed between the side portion 21 and the axial protrusion 2b, and at least one of the portions between adjacent axial protrusions 2b, 2b, and a receiving portion 2d is formed on the upper surface of this flat portion 23 to support and restrain the spacer 6 that maintains the gap between it and the bottom surface 41 of the existing girder 4, as shown in Figure 4.

[0063] The receiving portion 2d is formed in a shape that simply supports the spacer 6 or that can hold it from the periphery, depending on the shape of the bottom surface of the spacer 6. In the drawing, the receiving portion 2d is formed from a set of projections 2d1, such as four, on a plane so that the rectangular spacer 6 can be held from both the width and length directions of the bottom plate 2, but the shape and number of the receiving portion 2d are arbitrary. Of the multiple projections 2d1, some of the projections 2d1 are aligned in the width direction of the bottom plate 2, and other projections 2d1 are aligned in the length direction of the bottom plate 2.

[0064] In the drawings, particularly as shown in Figure 4, in order to accommodate two types of existing girders 4 with different widths, the receiving portions 2d, 2d located on one side of the widthwise center are arranged so as to be parallel to each other in the width direction of the bottom plate 2. In this case, as shown in Figure 1-(b), each receiving portion 2d is configured to be parallel to each other in the width direction of the bottom plate 2, and of the protrusions 2d1 parallel to each other in the width direction of the bottom plate 2, the wider protrusion 2d1 located in the middle serves as the protrusion 2d1 of both receiving portions 2d, 2d.

[0065] Since the filler material 5 is also filled between the side plate 3 of the connecting member 1 and the side surface 42 of the existing girder 4, the height direction protrusion 3a formed on the surface of the side plate 3 facing the side surface 42 functions to transmit the horizontal force in the length direction acting on the side plate 3 as a bearing pressure to the existing girder 4. When the horizontal force is transmitted from the height direction protrusion 3a, the horizontal force also acts on the filler material 5 filled between the height direction protrusions 3a, 3a.

[0066] Therefore, as shown in Figure 6, when the height-direction protrusion 3a is viewed in a plane or in a horizontal cross section, the width of the side plate 3 of the height-direction protrusion 3a in the longitudinal direction is formed into a cross-sectional shape that gradually increases from the side of the existing girder 4 to the inner surface of the side plate 3, making it possible to apply resistance to the horizontal force acting on the filler material 5 between the height-direction protrusions 3a, 3a to the filler material 5 as a bearing pressure.

[0067] As shown in Figures 1-(b), 1-(c), and 2-(c), the bottom plate 2 extends continuously beyond the side plate 3 on the opposite side of the existing girder 4, and has a protruding portion 2e formed therein for joining the additional device 7 to the connecting member 1. A plurality of insertion holes 2e1 for joining the additional device 7 are formed in this protruding portion 2e at intervals in the length direction of the bottom plate 2.

[0068] Axial protrusions 3b are formed continuously in the axial direction of the existing girder 4 on the upper part of the surface of the side plate 3 facing the existing girder 4, protruding toward the existing girder 4 and increasing the adhesive force between the filler 5 on the surface of the side plate 3 facing the existing girder 4. These axial protrusions 3b are continuous with the height direction protrusions 3a, 3a on both sides in the length direction of the side plate 3. The axial protrusions 3b are also elements that resist when a vertically downward force acts on the connecting member 1.

[0069] On the surface of the side plate 3 opposite the existing girder 4, outer protrusions 31 are formed with insertion holes 31a for suspending and supporting the connecting member 1 from the existing girder 4 when joining the connecting member 1 to the existing girder 4. A plurality of outer protrusions 31 are formed at appropriate intervals along the length of the bottom plate 2, and also serve to stiffen the side plate 3 when an external force acts on the side plate 3 in an out-of-plane direction.

[0070] As described above, the connecting member 1 is placed below the existing girder 4 with a distance between the bottom surface 41 and both side surfaces 42, 42 of the existing girder 4 as shown in Figures 8-(b) and 9-(a), and the filler material 5 is filled between the bottom surface 41 of the existing girder 4 and the bottom plate 2 of the connecting member 1, and between both side surfaces 42, 42 of the existing girder 4 and both side plates 3, 3 of the connecting member 1. For this reason, recesses 41a, 42a are formed on the bottom surface 41 and both side surfaces 42, 42 of the existing girder 4, which are the contact surfaces with the filler material 5, respectively, to ensure adhesion with the filler material 5, as shown in Figure 7.

[0071] There are no particular restrictions on the shape of each recess 41a, 42a, but each is formed to a depth that does not expose the reinforcing bars arranged inside the existing girder 4. In Figure 7, the recess 42a on the side surface 42 is formed in a truncated cone shape, and the recess 41a on the bottom surface 41 is formed in a strip shape that is continuous in the width direction between both side surfaces 42, 42. When viewed in the depth direction, each recess 42a, 41a is formed in a shape such that the cross-sectional area on the inside of the existing girder 4 is smaller than on the surface side. This is to ensure the bearing capacity when the filler 5 that enters the recesses 42a, 41a is subjected to a horizontal shear force from the inner circumferential surface of the recesses 42a, 41a.

[0072] For example, when a difference occurs in the horizontal forces acting on each of the side plates 3, 3 of the connecting member 1, and a torsional moment in the horizontal plane acts on the filler material 5 that has entered the recess 41a of the bottom surface 41, a bending moment is applied to the filler material 5 in a triangular shape, centered on the widthwise center of the existing girder 4 and increasing according to the widthwise distance.

[0073] For this reason, it is reasonable that the recess 41a on the bottom surface 41 of the existing girder 4 should be formed in a shape such that the axial width of the existing girder 4 gradually expands from the center of the width of the existing girder 4 to both sides in the width direction, as shown in Figure 7-(c) when looking up at the bottom surface 41. By forming the recess 41a in a shape such that the axial width of the existing girder 4 gradually expands from the center of the width of the existing girder 4 to both sides in the width direction, it is possible to make uniform the bending stress generated in the filler material in response to the bending moment distributed in a triangular shape, regardless of the distance from the center of the width of the existing girder 5.

[0074] Figures 4-(a) and (b) show the state in which the connecting member 1 shown in Figure 1 is combined and arranged with existing girders 4 of different widths. (a) shows the case in which the connecting member 1 is arranged below an existing girder 4 with the largest expected width, and (b) shows the case in which the connecting member 1 is arranged below an existing girder 4 with the smallest expected width. As shown here, the protrusion 2d1 used to support (hold) the spacer 6 as the receiving portion 2d can be changed depending on the difference in the width of the existing girder 4.

[0075] As shown in both figures, the surfaces of both side plates 3, 3 of the connecting member 1 facing the existing girder 4 are bent or curved so that the middle part in the height direction is slightly away from the side surface 42 of the existing girder 4 than the upper and lower parts in the height direction, and both sides of the side plate 3 in the height direction are closer to the existing girder 4 than the middle part. The bent parts 32, or bend lines, which are the bending positions when the side plate 3 is bent, are formed continuously or continuously in the length direction of the side plate 3.

[0076] In the example shown in Figure 4, the side plates 3 are formed in a shape such that both sides in the height direction approach the side surfaces 42 of the existing girder 4 from the middle, so that whether a vertical downward force or an upward force acts on the connecting member 1, the filler material 5, which is filled between the side surfaces 42 of the existing girder 4 and the side plates 3 of the connecting member 1 and has a trapezoidal cross section, exerts a reaction force from the hypotenuse of the trapezoid, thereby being able to exert resistance to the vertical force from the connecting member 1. As described above, the axial protrusions 3b also resist the vertical downward force.

[0077] Figure 9-(a) shows the state in which filler material 5 is filled between the existing girder 4 and the connecting member 1, the connecting member 1 is joined to the existing girder 4, and then a horizontal force distribution device (displacement limiting device) is connected to the connecting member 1 as an additional device 7. The filler material 5 is filled up to the height of the axial protrusion 3b on the side plate 3 of the connecting member 1, and penetrates into the recesses 41a, 42a on the bottom surface 41 and side surface 42 of the existing girder 4, and into the corrugated plates 2c1, 2c1 on the bottom plate 2 of the connecting member 1. When viewed from above, the filler material 5 penetrates between adjacent height direction protrusions 3a, 3a on the side plate 3, as shown in Figures 9-(b) and 9-(c).

[0078] The additional device 7 shown in Figure 9 has an opening 71a in the center on a plane, as shown in (a), for example, and has a box-shaped upper plate 71 that is joined directly or indirectly to the existing girder 4, which is the upper structure, a flat lower plate 72 that is joined directly or indirectly to the lower structure 8, such as a pier or abutment, and a stopper 73 that is joined integrally to the lower plate 72 and engages with the inner surface of the opening 71a of the upper plate 71 when the existing girder 4 moves relative to the lower structure 8.

[0079] 9, an upper mounting plate 74 that is joined to the overhanging portion 2e of the connecting member 1 is integrally joined to the upper surface of the upper plate 71, and a lower mounting plate 75 that is joined to the lower structure 8 is integrally joined to the lower surface of the lower plate 72. The upper mounting plate 74 is joined to the connecting member 1, for example, with bolts 76 that pass through insertion holes 74a formed in the upper mounting plate 74 and insertion holes 2e1 in the overhanging portion 2e, and the lower mounting plate 75 is joined to the lower structure 8 with bolts 76 that pass through insertion holes 75a formed in the lower mounting plate 75 and thread into, for example, drilled holes 8a formed in the top surface of the lower structure 8 or into insertion holes in brackets that are installed and fixed across the side and top surfaces of the lower structure 8.

[0080] A clearance for the allowable amount of relative movement is secured between the inner surface of the opening 71a of the upper plate 71 and the outer surface of the stopper 73, and a cushioning material 77 is adhered to the inner surface of the opening 71a to reduce the impact force between the stopper 73 and the inner surface of the opening 71a when relative movement occurs.

[0081] When the substructure 8 moves relative to the existing girder 4, a stopper 73 integrated into the lower plate 72 horizontally engages with the inner peripheral surface of the opening 71a of the upper plate 71, and a horizontal force is transmitted from the stopper 73 through the upper plate 71 and upper mounting plate 74 to the connecting member 1. The direction of the relative movement is mainly the axial direction of the existing girder 4 (the bridge axis direction), but it may also include a component in the width direction of the existing girder 4 (the direction perpendicular to the bridge axis).

[0082] The horizontal force transmitted to the connecting member 1 is transmitted to the existing girder 4 through the adhesive force and support pressure between the bottom surface 41 of the existing girder 4 and the filler material 5 present between both side surfaces 42, 42. Figure 9-(c) shows the situation in which the horizontal force is transmitted to the filler material 5 from the height direction protrusions 3a formed on the inner peripheral surface of the side plate 3 of the connecting member 1. The support pressure acts directly in a direction perpendicular to the side surfaces from the side surfaces on both sides in the width direction of the height direction protrusions 3a. [Explanation of symbols]

[0083] 1...connecting member, 2...Bottom plate, 21...Side part, 22...End part, 2a...Protrusion in the width direction, 2b...Protrusion in the axial direction, 2c...Stiffening part, 2c1...Corrugated plate, 23...Flat part, 2d...Receiving part, 2d1...Protrusion, 2e...Protrusion part, 2e1...Insertion hole, 3... Side plate, 3a... Height protrusion, 3b... Axial protrusion, 31... Outer protrusion, 31a... Insertion hole, 32... Bent part (bending line), 4... Existing girder, 41... Bottom surface, 41a... Recess, 42... Side surface, 42a... Recess, 5...Filling material, 6...Spacer, 7...Additional device, 71...Upper plate, 71a...Opening, 72...Lower plate, 73...Stopper, 74...Upper mounting plate, 74a...Through hole, 75...Lower mounting plate, 75a...Through hole, 76...Bolt, 77...Buffer material, 8...substructure, 8a...drilling.

Claims

1. A connecting member that is joined to an existing girder of a reinforced concrete bridge in order to connect an additional device that is additionally installed on the existing girder to the existing girder, The bottom plate and the side plate face each other at a distance from each other, and have a groove shape that surrounds the existing girder from below. At least a width direction protrusion facing the width direction of the existing girder is formed on the surface of the bottom plate facing the existing girder, and at least a height direction protrusion facing the height direction of the existing girder is formed on the surface of the side plate facing the existing girder, A connecting member for existing girders in a bridge, characterized in that a stiffening portion is formed in a portion of the bottom plate other than the widthwise protrusion, and when the bottom plate is viewed in the longitudinal direction, at least a portion of the stiffening portion is continuous in a wavy shape in the width direction of the bottom plate.

2. A connecting member for an existing girder according to claim 1, characterized in that the widthwise protrusions of the bottom plate are formed on the surface of the stiffening part facing the existing girder and on the opposite surface.

3. A connecting member for existing girders in a bridge as described in claim 1, characterized in that the widthwise protrusion of the bottom plate has a shape in which the width in the longitudinal direction of the bottom plate gradually increases from the existing girder side to the bottom plate side.

4. A connecting member for existing girders in a bridge as described in claim 1 or claim 3, characterized in that a flat portion having a width greater than the width of the widthwise protrusion in the longitudinal direction of the bottom plate is formed on the surface of the bottom plate facing the existing girder, facing the width direction of the existing girder, and a receiving portion is formed on the surface of this flat portion facing the existing girder for supporting a spacer that maintains the gap between the flat portion and the bottom surface of the existing girder.

5. A connecting member for existing girders in a bridge as described in claim 1 or claim 3, characterized in that the surface of the side plate facing the existing girder has a shape in which the distance between it and the side surface of the existing girder gradually decreases from the middle part in the height direction to the upper and lower parts in the height direction.

6. A joining structure in which the connecting member according to any one of claims 1 to 3 is joined to the existing girder, wherein recesses are formed on the bottom surface and both side surfaces of the existing girder, the connecting member is positioned with a distance between the bottom surface and both side surfaces of the existing girder, and a filler material is filled between the bottom plate and side plates of the connecting member and the existing girder.

7. A joint structure with an existing girder using a connecting member for an existing girder in a bridge as described in claim 6, characterized in that the recess on the bottom surface of the existing girder is formed in a shape such that the axial width of the existing girder gradually increases from the center of the width of the existing girder to both sides of the width.

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