JP5972108B2 - Joint structure of bridge girder and substructure - Google Patents

Description

  The present invention relates to a joint structure between a bridge girder and a lower structure that rigidly joins the end of a precast concrete bridge girder constructed between adjacent lower structures such as between adjacent abutments or between piers. It is.

  For example, in the case of a single-frame rigid frame bridge where both ends of the bridge girder (main girder) are rigidly joined to the lower structure such as an abutment, such as a pedestrian bridge and a roadway bridge, the bending moment and shear force generated at the end of the bridge girder are lower structures. Since it is transmitted in a concentrated manner, the burden on the lower structure is greater than in the case of multi-span continuous bridges, so only the transmission of force between the bridge girder and the lower structure is ensured. It is necessary to have the ability.

  In this case, in order to transmit the bending moment from the bridge girder through the joint to the lower structure, it is essential to ensure the yield strength against the tensile force at the joint, so the strength depends on the steel material, and the steel material is used for the bridge girder and the lower structure. In many cases, it is arranged at the joint so as to straddle both sides (see Patent Documents 1 to 3).

  However, as disclosed in Patent Documents 1 to 3, for example, in a method in which steel material is embedded in the end portion of the bridge girder and the steel material is joined to the abutment, the reinforcing bars for reinforcing the concrete existing around the steel material when the bridge girder and the abutment are joined. In addition to the complexity of construction, the construction of the bridge girder is also complicated by the amount of steel embedded in the girder.

  On the other hand, there is also a method of simplifying the joint by placing PC steel straddling between the bridge girder and the abutment and introducing prestress that cancels the tensile force accompanying the bending moment generated at the end of the bridge girder and the upper part of the abutment. (See Patent Document 4).

JP 2007-132046 A (Claim 1, paragraph 0031, FIGS. 2 to 5) JP 2007-284914 A (Claim 1, paragraphs 0034 to 0038, 0045, FIG. 2, FIG. 8) JP 2010-101094 A (Claim 1, paragraphs 0020 to 0032, 0045 to 0071, FIGS. 16 to 8) JP 2002-266503 A (Claims 1 and 2, paragraphs 0007 to 0014, FIGS. 1 to 3)

  However, in the method of resisting the bending moment generated at the joint by introducing prestress, it is difficult to simultaneously act on the axial direction of the bridge girder and the substructure with one PC steel material. PC steel cannot be continuously arranged between the bridge girder and the lower structure, and requires PC steel arranged along the bridge girder and PC steel arranged along the abutment (paragraph 0016 of Patent Document 4). FIG. 1 and FIG. 5). When one PC steel material is continuously arranged between the bridge girder and the lower structure via the joint, unnecessary compression is applied from the outer peripheral side to the inside at the joint, which is a corner portion on the PC steel material arrangement. This is because force (abdominal pressure) is applied and rational reinforcement is not possible.

  On the other hand, in Patent Document 4, in order to suppress the bending deformation of the bridge girder itself or to reduce the thickness due to the bending deformation suppressing effect, an attempt is made to arrange the PC steel material parallel to the bridge axis perpendicular direction (width direction) inside the bridge girder. In this case, since two types of PC steels with different roles are mixed and fixed in the joint, it is necessary that both the bridge girder and the abutment have a sufficient cross section for the placement and fixing of the PC steel. As a result, the result is contrary to the demand for thinning.

  In the present invention, the bridge girder made of precast concrete and the lower structure that enables the end of the bridge girder to be rigidly joined to the lower structure with a simple structure while allowing the wall girder itself to be thinned. A partial structure is proposed.

The joint structure between the bridge girder and the lower structure according to the first aspect of the present invention includes a bridge girder made of precast concrete, which is constructed on an adjacent lower structure and rigidly joined to the lower structure at both ends, and the lower structure. A joint structure,
The bridge girder includes a floor slab portion, and at least a lower side of both sides in the width direction of the floor slab portion, and both side ribs projecting toward the bridge axis direction of the floor slab portion, from the top end of the lower structure Has a protruding vertical line,
The bridge girder is placed on the top end of the lower structure on the both side ribs, and the vertical bars of the lower structure are arranged between the side ribs, and the vertical bars are embedded between the side ribs. Or the mortar is integrated and the bridge girder is joined to the substructure ,
An intermediate rib that faces the bridge axis direction of the floor slab in a section that includes a region on the top end of the lower structure, at least near the end of the floor slab, between the side ribs below the floor slab Projecting, and the vertical bars of the lower structure are arranged in the concrete or mortar other than the intermediate ribs,
It is a structural requirement that the horizontal stripes arranged perpendicular to the vertical bars in the portion located on the top end of the lower structure and fixed to the both side ribs pass through the intermediate ribs in the width direction. .

  Since the bridge girder constitutes a single-span or multi-span ramen bridge together with the substructure, the bridge form is such that the bridge girder is built between abutments, such as pedestrian bridges, road bridges, etc. There is a type in which the bridge girder is supported between the bridge piers and between the adjacent piers, and adjacent bridge girders are supported on the same pier. Therefore, since the bridge girder may be installed between the abutment and the pier, or between the piers, the substructure includes the abutment and the pier. The multi-frame ramen bridge includes the case where the bridge pier in the axial direction of the bridge has a shoe structure (sliding support).

  “Both side ribs projecting at least below both sides in the width direction of the floor slab” means that both side ribs project only on the lower side (bottom side) of both sides in the width direction of the floor slab. As shown in 1 etc., it means that it may be provided on the lower side and the upper side (upper surface side). “Towards the bridge axis direction of the floor slab portion” means that both side ribs are formed along the bridge axis direction of the floor slab portion. The “width direction of the floor slab portion” mainly refers to a direction perpendicular to the bridge axis, but when the floor slab portion is, for example, a parallelogram, it refers to the short side direction.

  The bridge girder has ribs on both sides in the width direction of the floor slab, so that it has a groove shape (reverse groove shape) or H-shaped cross section when viewed in the bridge axis direction, and the bending moment received by the bridge girder on both sides ribs It works to transmit to the lower structure while burdening with the floor slab part. The bridge girder has a groove-shaped cross-sectional shape when both side ribs are formed only on the lower side of the floor slab part, and has an H-shaped cross-sectional shape when formed on the upper side. Basically, it is determined according to the bending moment distribution of the bridge girder due to the load on the floor slab. Both side ribs may be formed over the entire length of the floor slab in the bridge axis direction, or may be formed in a section near the end of the floor slab. The “section near the edge of the floor slab” is the section from the position of the bridge girder in the axial direction (center) of the bridge girder to the edge of the lower structure, including the area on the top edge of the lower structure May not include.

  The ribs on both sides of the bridge girder are transferred to the lower structure while bearing the bending moment of the bridge girder together with the floor slab part, so that only the floor slab part is freed from the bending moment, and the floor slab part is made thinner. Contribute. Thinning of the floor slab portion is also possible by introducing prestress by a tension member 35 such as a PC steel material arranged in the bridge axis direction inside the floor slab portion 31 as shown in FIGS. Yes.

  The ribs on both sides give the bridge girder rigidity with respect to the bending moment in the direction of the bridge axis and also serve to suppress bending deformation of the bridge girder. As shown in FIG. 8, the ribs 32 on both sides correspond to the distribution of bending moment generated in the bridge girder 3 and are formed in a shape in which the height (composition) gradually increases from the bridge axial direction intermediate side to the end of the bridge girder 3. This increases the girder height at the end of the bridge girder 3 and increases the rigidity and yield strength at the end of the bridge girder 3.

Between the side ribs 32, 32 of the floor plate portion 31 downward, towards the end portions of the section of at least the floor plate 31, parallel to each side ribs 32, 32, intermediate ribs 33 Ru is projected. The intermediate rib 33 supplements the roles of the both side ribs 32 and 32 and functions to transmit the bending force acting on the floor slab 31 together with the floor slab 31 and the both side ribs 32 and 32 to the lower structure 1.

One or a plurality of intermediate ribs 33 are provided so as to face the bridge axis direction of the floor slab portion 31 and are parallel to both side ribs 32. Similarly the intermediate ribs 33 and the both side ribs 32, since that is also a resistive element for the bridge axis direction of bending moments generated in the bridge girder 3, Ru is projected towards the end portions of the section of at least the floor plate 31. Since a period of at least an end portion near the intermediate ribs 33, including the area on the top end of the lower structure 1, there have is sometimes formed on the entire length of the deck portion 31. As shown in FIGS. 1 and 4, the height of the intermediate rib 33 corresponds to the bending moment distribution, and it is rational that the intermediate rib 33 is formed in a shape that gradually decreases from the end of the bridge girder 3 toward the intermediate portion. . When the intermediate ribs 33 are formed on the floor slab 31, the vertical bars 2 of the lower structure 1 are arranged in the concrete 4 other than the intermediate ribs 33 as shown in FIGS. 2 and 5.

The intermediate ribs 33 projecting between the both side ribs 32, 32 below the floor slab 31 are located in the region above the top end of the lower structure 1 (joint 30) below the floor slab 31 as described above. 4 and 5, the concrete 4 or the like as the cross beam portion 34 is integrally formed as a part of the floor slab portion 31 (Claim 2 ), and shown in FIGS. Thus, when the intermediate part rib 33 is continuously formed from the position near the intermediate part of the floor slab part 31 to the section including the region (joint part 30) on the top end of the lower structure 1 (Claim 3 ). There is.

If the concrete 4 or the like to be integrated into the bridge girder 3 is classified, the concrete 4 or the like is preliminarily produced when the bridge girder 3 is formed as a part of the cross girder part 34 of the bridge girder 3 as shown in FIGS. When formed (Claim 2 ) and when integrated by being filled (placed) on-site at the time of joining to the lower structure 1 as shown in FIG. 1, FIG. 2, FIG. 6, and FIG. (Claims 3 and 4 ). In the case of integrating in the field (claim 3, 4), including the case where the concrete 4 and the like is filled only to the joint 30 on the lower structure 1 (claim 3), the joint portion 30, claim 1 when filling the forming section of the intermediate ribs 33 of ~ 3 is (claim 4). 4 to 7 show a state in which the intermediate ribs 33 are not continuous up to the top end of the lower structure 1, FIGS. 4 to 7 themselves show a reference example of the present invention. 4 to 7, if it is considered that the intermediate ribs 33 are formed on the top end of the lower structure 1, these can be seen as drawings showing the present invention.

In the case of the example shown in FIGS. 4 and 5 (Claim 2 ), the region on the top end of the lower structure 1 where the cross beam portion 34 made of concrete 4 or the like is between the side ribs 32, 32 below the floor slab portion 31. It is formed in the (joining part 30) as a part of the bridge girder 3 facing the width direction of the floor slab part 31, and is integrated between the floor slab part 31 and both side ribs 32 and 32. “Towards the width direction of the floor slab portion 31” means that the length direction of the cross beam portion 34 faces the width direction of the floor slab portion 31. In this case, the vertical bars 2 of the lower structure 1 are arranged and embedded in the cross beams 34 other than the intermediate ribs 33 as shown in FIG .

  In the example shown in FIGS. 4 and 5, an insertion hole 34a is formed in the insertion portion of the vertical bar 2 of the cross beam 34, and the vertical bar 2 is inserted into the insertion hole 34a, and a filler such as mortar is used on the site. By filling, the vertical bars 2 are embedded in the cross beam 34 such as concrete 4 and fixed. The horizontal girder 34 has a thickness in the thickness direction of the lower structure 1 that is equal to the thickness of the top end portion of the lower structure 1, and the floor in the width direction of the lower structure 1 (width direction (width direction) of the bridge girder 3) It has a length equivalent to the width of the printing plate 31.

In the case of the example shown in FIGS. 1 and 2 (Claim 3 ), the intermediate rib 33 includes a region (joint portion 30) on the top end of the lower structure 1 from a position near the intermediate portion of the floor slab portion 31. The concrete 4 or the like is filled between the side ribs 32 and the intermediate ribs 33 adjacent to each other in the width direction of the floor slab portion 31 and between the intermediate ribs 33 and 33. The concrete 4 or the like to be filled in each region defined by the intermediate ribs 33 along with the portion (end portion 33a) on the top end of the lower structure 1 of the intermediate ribs 33 is the side of the example shown in FIGS. The digit part 34 is configured. As shown in FIG. 2, the vertical bars 2 of the lower structure 1 are embedded and fixed in the concrete 4 or the like for each region defined by the intermediate ribs 33.

  The intermediate ribs 33 in the example shown in FIGS. 1 and 2 are continuous up to the region on the top edge of the lower structure 1, so that the concrete 4 filled between the side ribs 32 and the intermediate ribs 33 is placed. Therefore, the filling region of concrete 4 or the like is partitioned, and it is possible to efficiently fill the limited region with the concrete 4 or the like.

In the case of the examples shown in FIGS. 6 and 7 (Claim 4 ), the concrete 4 or the like includes a floor slab part including at least a region on the top edge of the lower structure 1 between both side ribs 32, 32 below the floor slab part 31. A section near the end of 31 is filled, and the vertical bars 2 of the lower structure 1 are embedded in the concrete 4 or the like on the top end of the lower structure 1. "Area (section) on the top edge of the lower structure 1" refers to the joint 30 of the bridge girder 3 with the lower structure 1, and concrete 4 or the like filled in this area is an example shown in FIGS. The cross beam portion 34 is configured. “At least” means that there is a case where filling is performed from a region (joint portion 30) on the top end of the lower structure 1 to a section near the intermediate portion in the bridge axis direction of the floor slab portion 31 as shown in FIG. .

In the example shown in FIGS. 6 and 7, the concrete 4 or the like has a width over the entire width of the floor slab portion 31 by being integrated with the bridge girder 3. As a result, the concrete 4 or the like is at least in the section near the end of the bridge girder 3. Since the thickness of the floor slab portion 31 is increased, it is possible to increase the rigidity and proof stress in the section of the bridge girder 3 at least near the end. In this case, since the concrete 4 and the like are integrated with the bridge girder 3 at the site, the weight of the bridge girder 3 itself can be reduced as compared with the case of claim 2 in which the horizontal girder portion 34 is integrated in advance.

In the concrete 4 or the like that is integrated with both side ribs 32, 32 on the joint 30 on the top end of the lower structure 1, a part of the intermediate rib 33 continues to the joint 30 on the lower structure 1 (see FIG. 1 and FIG. 2), a cross beam portion 34 is formed together with a part of the intermediate rib 33 .

In other words, the “concrete 4 etc. integrated between the side ribs 32, 32” including the cross beam part 34 is a bridge girder between the side ribs 32, 32 of the floor slab part 31 as shown in FIGS. 4 and 5. 3 is preliminarily integrated as a part of claim 3 (Claim 2 ), and is inserted (filled) between the ribs 32, 32 on the site as shown in FIG. 1, FIG. 2, FIG. 6, and FIG. In some cases, the bridge girder 3 is integrated (claims 3 and 4 ). When concrete 4 or the like is placed on site (Claims 3 and 4 ), the concrete 4 or the like is at least within the range of the thickness of the lower structure 1 (distance in the bridge axis direction of the bridge girder 3). On the joint 30 on the top end), the part on the top end of the lower structure 1 becomes a part of the bridge girder 3 as a horizontal girder part 34 so as to be integrated between the opposite side ribs 32, 32 of the bridge girder 3. .

The concrete 4 or the like in claim 4 shown in FIGS. 6 and 7 is filled (placed) from a region on the top edge of the lower structure 1 to a section near the intermediate portion in the bridge axis direction of the floor slab portion 31. The bridge girder 3 is integrated with the floor slab portion 31 over the entire width of the floor slab portion 31 in the width direction over the section of the intermediate rib 33 including the transverse girder portion 34 in claims 2 and 3 . Therefore, the rigidity and proof stress in the section near the end of the bridge girder 3 are increased. Also in this case, the concrete 4 or the like works to increase the rigidity and proof strength of the bridge girder 3, so it is bent from the end of the bridge girder 3 to the middle part and bent as shown in FIGS. 6 and 8 when the bridge girder 3 is viewed in the width direction. It is reasonable to give a cross-sectional shape corresponding to the moment distribution.

  If the structure consisting of the bridge girder 3 and the lower structure 1 is viewed as a single-frame rigid frame bridge, the bending moment due to the load on the bridge girder 3 generates a tensile stress on the upper side near the end of the bridge girder 3 and on the lower side in the middle part. A distribution in which tensile stress is generated. Accordingly, as shown in FIG. 8, both side ribs 32, 32 integrated with the floor slab 31 are formed on the upper side with respect to the floor slab 31 near the axial middle of the floor slab 31, and closer to the end in the axial direction. Thus, the floor slab portion 31 is formed on the lower side, so that the tensile stress caused by the bending moment can be borne on the floor slab portion 31. In this case, the bridge girder 3 as the upper structure cancels the tensile stress of the bending moment in the bridge axis direction generated in the bridge girder 3 by the prestress due to the tension member 35 inserted in the floor slab portion 31 as shown in FIG. It becomes a suitable structure.

  As shown in FIG. 8, when the bridge girder 3 as the upper structure is viewed from the side (elevation), the side ribs 32 have a curved shape that is convex upward as a whole, and the floor slab portion 31 that is a horizontal version has both side ribs. The bridge girder 3 is in the form of a middle path by being positioned on the upper side of the both side ribs 32 near the end of 32 and below the both side ribs 32 near the intermediate part. In this way, the floor slab portion 31 is positioned above the both side ribs 32 near the ends of the both side ribs 32, so that when the bridge girder 3 is placed on the lower structure 1 on the both side ribs 32, It is possible to place the reinforcement 2 deeply in the concrete 4 or the like under the floor slab 31 and to arrange many transverse reinforcements 5 in the height direction, ensuring the integrity of the lower structure 1 and the bridge girder 3. It is easy to do.

According to the third aspect of the present invention , a portion (end portion 33 a) of the intermediate rib 33 located on the top end of the lower structure 1 is arranged in the width direction so as to be perpendicular to the vertical stripe 2 of the lower structure 1. It is used to insert (engage the force distribution muscle) and engage. By arranging the transverse bars 5 through the intermediate ribs 33 (ends 33a) in the width direction in the floor slab part 31, the bending moment acting on the bridge girder 3 is dispersed in the width direction, so that the vertical structure of the lower structure 1 is obtained. Since it can transmit to the muscle | muscle 2, the effect of distributing the burden of the lower structure 1 in the width direction improves. Further, since the horizontal bars 5 can be engaged with the intermediate ribs 33, the tensile force borne by the vertical bars 2 is transmitted to the bridge girder 3 and the tensile forces borne by the bridge girder 3 are applied to the vertical bars 2 of the lower structure 1. The effect of transmission is also improved.

In the case shown in FIGS. 1, 2, 6, and 7, the concrete 4 or the like that becomes the cross girder portion 34 of the floor slab portion 31 is filled (placed) on-site when the bridge girder 3 and the lower structure 1 are joined. (Claims 2 and 3 ), in addition to this, a tension material such as a PC steel material is inserted in the width direction between both side ribs 32, 32 of the floor slab portion 31 to give a tension to it, and prestress is applied to the concrete 4 and the like. It is also possible to reinforce the integrity between the ribs 32, 32 and the concrete 4 or the like. In that case, it is also possible to use the transverse muscle 5 shown in FIG. 1, FIG. 2, FIG.

It is possible to arrange the horizontal bars 5 by embedding in the cross beam portion 34 in the examples of FIGS. 4 and 5 (Claim 2 ) as well, and the examples of FIGS. 6 and 7 (Claims). Also in 4 ), it is possible to arrange the bars by crossing the vertical bars 2 when placing concrete 4 or the like on site.

4, the lower structure 1 on the portion of the intermediate ribs 33 in the claim 4, crossbeam 34 on claim 2, the lower structure 1 crest shown in FIG. 5 is shown in FIG. 1, FIG. 2 (end 33a) The cross girder portion 34 is completed as a part of the bridge girder 3 on the site .

  As described above, the bridge girder 3 is filled (placed) or formed between the side ribs 32 and 32 while ensuring a certain resistance against bending moment due to its own weight and live load by forming the side ribs 32 and 32 at least. The bridge girder 3 itself has the resistance to the bending moment and the ability to transmit the bending moment to the lower structure 1 in order to ensure high rigidity and proof strength by the integrated concrete 4 and the like and the side ribs 32, 32. Will do. The bridge girder 3 itself has a resistance to bending moment and the ability to transmit the bending moment, so that the bridge girder 3 has a special resistance to resist the bending moment, such as the embedding of steel and the placement of PC steel for the bending moment. It is no longer necessary to apply reinforcement.

  By eliminating the need for special reinforcement for the bridge girder 3, the bridge girder 3 is basically placed on the top end of the lower structure 1 on both side ribs 32, 32 and protrudes from the top end of the lower structure 1. Is rigidly joined to the lower structure 1 only by arranging the bars between the ribs 32, 32 and by integrating the concrete 4 or the like in which the vertical bars 2 are embedded in the ribs 32, 32. Become. The concrete 4 or the like integrated between the ribs 32 and 32 transmits the compressive force between the bridge girder 3 and the lower structure 1, and the tensile force between the bridge girder 3 and the lower structure 1 protrudes from the lower structure 1. The streak 2 is embedded in the concrete 4 or the like, and is transmitted by being fixed.

In any of the examples shown in FIGS. 1 to 7 (Claims 1 to 4 ), the bridge girder 3 has both side ribs 32, 32, and a cross girder 34 such as concrete 4 is provided between the side ribs 32, 32 of the bridge girder 3. As a result of the integration, no special reinforcement is required for the bridge girder 3, so that the vertical bars projecting from the lower structure 1 in the space (region) sandwiched between the ribs 32, 32 on the top end of the lower structure 1. The need to arrange any reinforcing elements (members) that could be an obstacle to the second bar arrangement is eliminated.

  As a result, in any of the examples (Claims 1 to 5) including the examples of FIGS. 1 and 2, the longitudinal bars 2 are substantially in the region (space) sandwiched between the ribs 32 and 32 on both sides of the bridge girder 3. Since it is possible to arrange the entire bar, it becomes possible to arrange a sufficient number of vertical bars 2 as tensile resistance elements of the joint 30 between the bridge girder 3 and the lower structure 1. On the other hand, it is not necessary to arrange (add) a special reinforcing material.

After all, in any case of Claims 1-4 , concrete 4 etc. which embed the vertical stripe 2 of lower structure 1 between both side ribs 32 and 32 of the field on the top end of lower structure 1 are integrated. As a result, the joint portion 30 of the bridge girder 3 with the lower structure 1 is reinforced concrete structure that does not require a reinforcing element, but ensures high rigidity, and the vertical bars 2 of the lower structure 1 can be closely arranged in the concrete 4 or the like. In addition, it possesses high proof strength against tensile and compressive forces due to bending moments.

  The bridge girder 3 is basically made of precast concrete (reinforced concrete (including prestressed concrete)), but mortar mixed with reinforcing fibers for increasing tensile strength may be used instead of concrete. Even in that case, the bridge girder 3 is precast, so it is substantially equivalent to precast concrete. When a mortar mixed with reinforcing fibers is used, the floor slab portion 31 can be made thinner. The bridge girder 3 shown in the figure has a prestressed concrete structure in which the tension members 35 are arranged in the axial direction of the floor slab portion 31 as described above.

  The mortar in parallel relation with the concrete is free of coarse aggregate mixed in the concrete. As shown in FIGS. 4 and 5, the concrete 4 or the like in which the vertical bars 2 are embedded is the floor slab portion 31. It is also used as a filler that fills the insertion hole 34a in the case of being integrated into the insertion hole 34a. Moreover, it can be used as a material to replace concrete because it can obtain high compressive strength and tensile strength that are not inferior to concrete due to fiber mixing in mortar. Fiber mixed mortar may have a tensile strength higher than that of concrete.

  The bridge girder made of precast concrete to be rigidly joined to the substructure is equipped with ribs on both sides projecting toward the bridge axis direction of the floor slab at least on both sides in the width direction. Since the ribs on both sides serve to transmit to the lower structure while being borne, it is not necessary to give the bridge girder extraordinary reinforcement to resist bending moment. Therefore, it is possible to eliminate any reinforcing element (member) from the space (region) sandwiched between the ribs on both sides of the bridge girder on the top edge of the substructure. A sufficient number of longitudinal bars as tensile resistance elements between the lower structure and the lower structure can be arranged.

As a result, the bridge girder is placed on the top edge of the lower structure on both side ribs, and the vertical bars protruding from the top edge of the lower structure are arranged between both side ribs, and the vertical bars are embedded between both side ribs It becomes possible to rigidly join the substructure only by integrating the concrete or mortar to be integrated.

Longitudinal sectional view seen in the width direction showing the joint between the bridge girder and the lower structure in which the intermediate ribs are continuously formed from the section near the edge of the floor slab to the area on the top edge of the lower structure FIG. 2 is a cross-sectional view taken along the line zz in FIG. (A) is the xx sectional view taken on the line of FIG. 1, (b) is the yy sectional view taken on the line of FIG. It is the longitudinal cross-sectional view which showed the example of formation of the penetration hole in the intermediate part rib of the bridge girder shown in FIG. Longitudinal sectional view seen in the width direction showing the joint between the bridge girder and the lower structure where the transverse girder made of concrete or the like facing the width direction is formed in the region on the top edge of the lower structure between the ribs on both sides FIG. 6 is a cross-sectional view taken along the line z-z in FIG. (A) is the xx sectional view taken on the line of FIG. 4, (b) is the yy sectional view taken on the line of FIG. The width between the ribs on both sides, showing the joint between the bridge girder filled with concrete, etc. with a transverse girder in the section near the edge of the floor slab, including the area on the top edge of the lower structure, and the lower structure It is the longitudinal cross-sectional view seen to the direction, and is the zz sectional view taken on the line of Fig.7 (a). (A) is the xx sectional view taken on the line of FIG. 6, (b) is the yy sectional view taken on the line of FIG. It is the elevation which showed the whole pedestrian bridge as an example of a ramen bridge. (A)-(d) is the perspective view which showed the construction procedure which joins a bridge girder to the abutment as a lower structure with the joining method shown in FIG. 1, FIG. It is the perspective view which showed the completion state of the footbridge as a ramen bridge completed through the construction procedure shown in FIG.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

  1, 4, and 6 are precast concrete bridge girders 3 that constitute a ramen bridge shown in FIG. 8 that is constructed on adjacent lower structures 1 and 1 and rigidly joined to the lower structures 1 and 1 at both ends. The example of the junction part of and the lower structure 1 is shown.

  The ramen bridge to which the present invention is directed includes a ramen bridge of one span and a ramen bridge in a form in which it is continuously arranged, and the lower structure 1 may be an abutment or a pier. Although FIG. 8 shows an example of a pedestrian bridge, a roadway bridge, a railway bridge, and the like are included for use. The substructure 1 in the illustrated example represents an abutment. The bridge girder 3 is mainly made of reinforced concrete, but may be made of super strength fiber reinforced concrete using mortar mixed with reinforcing fibers instead of concrete.

  A cross section taken along line xx and a line taken along line yy in FIG. 1 are shown in FIGS. Similarly, FIGS. 5A and 5B show a cross section taken along line xx and a line y-y in FIG. 4, and FIG. 7 shows a cross section taken along line xx and a line y-y in FIG. -Shown in (a) and (b). FIG. 3 shows a single bridge girder 3 in FIG. 1 shows a cross section taken along line zz in FIG. 2- (a), FIG. 4 shows a cross section taken along line zz in FIG. 5- (a), and FIG. 6 shows z in FIG. The cross section of the -z line is shown. 2- (a), (b), FIG. 5- (a), (b), FIG. 7- (a), (b), the mark in the floor slab 31 of the bridge girder 3 indicates the floor slab. A tension material 35 such as a PC steel material, which is arranged in the portion 31 along the bridge axis direction and introduces prestress to the floor slab portion 31 is shown.

  As shown in FIGS. 2A and 2B, the bridge girder 3 is provided so as to face the bridge axis direction of the floor slab portion 31 on at least the lower side of both sides of the floor slab portion 31 in the width direction. The lower structure 1 is located on the top end of the lower structure 1 and is joined in a section sandwiched between the both side ribs 32 and 32 at the bridge axial direction end of the bridge girder 3. . The section of the bridge axial direction end portion of the bridge girder 3 that is located on the top end of the lower structure 1 and is joined to the lower structure 1 is hereinafter referred to as a joint 30.

  Since the bridge girder 3 is placed on the top end of the lower structure 1 at both side ribs 32 and 32 as shown in FIG. 9- (b), the bridge girder 3 bridge end in the axial direction that defines the joint 30 on the lower structure 1 The length of the section (joint portion 30) is equal to or less than the thickness of the top end of the lower structure 1 (the distance in the bridge axis direction of the bridge girder 3).

  Since the both side ribs 32 and 32 are placed on the top end of the lower structure 1 in the section of the joint portion 30, the lower end surface of the end portion 32 a that divides the joint portion 30 out of the total length of the both side ribs 32 and 32 is For example, if the top end surface of the lower structure 1 has a flat horizontal surface, the lower end surfaces of the end portions 32a of the side ribs 32 and 32 are also formed in a flat horizontal surface. When the top end surface is a flat surface or a curved surface that is inclined with respect to the horizontal, the lower end surface of the end portion 32a is also formed into a flat surface or a curved surface corresponding thereto. In FIG. 1, the region sandwiched between the top end of the lower structure 1 and the floor slab portion 31 represents both side ribs 32, and the range sandwiched between the broken lines on the extension line of the line indicating the thickness of the lower structure 1 is the end. Part 32a.

  In the drawing, the ribs 32, 32 are made to correspond to the bending moment distribution caused by the long-term load including the weight of the bridge girder 3 as shown in FIG. 8, and the height is gradually increased from the center part to the end part in the bridge axis direction of the floor slab part 31. In this way, the resistance (bending stress degree) to the bending moment in each cross section in the bridge axis direction is made uniform. In the drawing, both side ribs 32 and 32 are also formed on the upper side of the floor slab portion 31 so that the amount of protrusion to the lower side of both side ribs 32 and 32 does not increase. The part which protruded above the floor slab part 31 of the both-sides ribs 32 and 32 is utilized as a handrail.

  From the top end of the lower structure 1 to which the bridge girder 3 is joined, the vertical bars 2 arranged within the joint portion 30 between the end portions 32a and 32a of the both side ribs 32 and 32 protrude, and this end portion 32a, The bridge girder 3 is joined to the lower structure 1 by integrating concrete 4 or mortar (hereinafter, concrete 4 or the like) in advance or on site within the range of the joint portion 30 between 32a. The concrete 4 or the like integrated into the joint 30 of the bridge girder 3 is filled (placed) on site after being placed on the lower structure 1 of the bridge girder 3 as in the examples shown in FIGS. As in the example shown in FIG. 4, there is a case in which the cross girder part 34 constituting a part of the bridge girder 3 is formed integrally with the bridge girder 3 together with an intermediate part rib 33 described later.

  In FIGS. 1 and 4, intermediate ribs 33 facing the bridge axis direction of the floor slab 31 are provided in a section near the end of the floor slab 31 including at least the joint 30 between both side ribs 32, 32 of the bridge girder 3. FIG. 6 shows an example in the case of being protruded, and FIG. 6 shows a case where concrete 4 or the like is filled in a section between both side ribs 32, 32 of the bridge girder 3 and at least an end portion of the floor slab portion 31 including the joint portion 30. It is an example. The “section near the end of the floor slab portion 31” refers to a section from the joint portion 30 or from the vicinity of the joint portion 30 to the intermediate portion in the bridge axial direction of the bridge girder 3 or the central portion side. It is formed from the bridge axis direction intermediate part (center part) side of the floor slab part 31 to the end part side. Since it is “at least”, the intermediate rib 33 may be formed over the entire length of the bridge girder 3.

The intermediate rib 33 is continuously formed from the center side in the bridge axis direction of the floor slab portion 31 to the end portion, but continues to the range including the joint portion 30 on the lower structure 1 as shown in FIG. To do .

  The “section near the end of the floor slab 31” includes the joint 30 with the lower structure 1 or excludes the joint 30, and the intermediate portion in the bridge axis direction of the floor slab 31 from the end of the floor slab 31. Alternatively, it is a section that transitions to the center part in the bridge axis direction, and may extend to the entire length of the bridge girder 3 or to a section before the center part in the bridge axis direction as shown in FIG. The intermediate rib 33 has a role of increasing the bending rigidity of the bridge girder 3 together with the both-side ribs 32, but the shape, section and height of the intermediate rib 33 can be freely determined according to the shape and height of the both-side ribs 32. .

  1 and 2, in particular, the intermediate rib 33 is continuously formed from the bridge axis direction intermediate portion side of the floor slab portion 31 to a region (joint portion 30) on the top end of the lower structure 1. The example in which the edge part 33a which lies on the top end of the lower structure 1 and divides the junction part 30 is formed continuously is shown. The end portion 33 a of the intermediate rib 33 faces the end portion 32 a of the both side ribs 32 in the width direction. In FIG. 1, the end surface (end surface of the end portion 33 a) of the intermediate rib 33 on the bridge axis direction end side is aligned with the end surfaces of the both-side ribs 32 (end surface of the end portion 32 a).

  In the example of FIGS. 1 and 2, the intermediate rib 33 has an end portion 33 a that faces the end portions 32 a of both side ribs 32, so that the intermediate rib 33 has a region (space) of the joint portion 30 on the lower structure 1. Since the concrete 4 and the like are divided in the width direction, the concrete 4 or the like is divided into divided areas, that is, between the end portions 32a of the side ribs 32 and the end portions 33a of the intermediate ribs 33 adjacent to each other in the width direction of the floor slab portion 31 and the intermediate portion. The ribs 33 and 33 are filled (placed) in units between the end portions 33a and 33a.

  In this case, the end portion 33a of the intermediate rib 33 is disposed on the top end of the lower structure 1 together with the end portions 32a of the both side ribs 32, so that each end portion 33a, 32a hits the top end of the lower structure 1. Since the placement area of concrete 4 and the like and the bar arrangement area of the vertical bars 2 are divided in the width direction, and also serves as a weir plate (formwork) in the width direction when filling the concrete 4 etc., the concrete 4 etc. It is filled in a state in which weir plates (framework) are arranged on both sides in the thickness direction of the structure 1 (bridge girder 3 bridge axis direction).

  The vertical bars 2 of the lower structure 1 are embedded and fixed in the concrete 4 or the like in a region defined by the end portions 32 a of the both side ribs 32 and the end portions 33 a of the intermediate ribs 33. The concrete 4 or the like filled in the region of the joint portion 30 on the lower structure 1 includes a portion corresponding to the cross beam portion 34 in the example of FIG. 4 together with the end portions 32a of the both-side ribs 32 and the end portions 33a of the intermediate ribs 33. Become.

  In the case where the end 33a of the intermediate rib 33 is not directly placed on the top end surface, such as floating from the top end surface of the lower structure 1, the lower end surface of the intermediate rib 33 is aligned with the top end surface of the lower structure 1. However, when placed on the top end surface of the lower structure 1, the lower end surface of the end portion 33 a of the intermediate rib 33 is the same as the lower end surface of the end portions 32 a of the both side ribs 32. It is formed in a flat shape or a curved shape matching the top end surface.

  In the case where the intermediate rib 33 divides the region of the joint portion 30 in the width direction, the transverse bars (distribution bars) 5 that distribute the bending moment generated in the bridge girder 3 in the width direction and transmit it to the lower structure 1 are arranged. In addition, it is also used to hold the transverse muscle 5 and receive a force from the longitudinal muscle 2 borne by the transverse muscle 5. In FIG. 1 and FIG. 2, the horizontal stripes 5 are arranged in the width direction of the floor slab 31 by passing the intermediate ribs 33 between the ribs 32, 32.

  In FIG. 2- (a) which shows a cross section when the bridge 30 of the joint 30 in FIG. 1 is viewed in the direction of the bridge axis, the vertical bars 2 of the lower structure 1 are omitted, but the vertical bars 2 are not shown in FIG. As shown to (a), it arrange | positions by the area unit divided by the intermediate part rib 33 (end part 33a). Since the vertical bars 2 function to transmit the tensile force generated by the bending moment from the bridge girder 3 to the lower structure 1, two or more rows are arranged in the thickness direction of the lower structure 1, and the ends of the intermediate ribs 33 are arranged accordingly. The horizontal stripes 5 that pass through the portion 33a are also arranged in two or more rows in the thickness direction of the lower structure 1. The transverse bars 5 cross each other directly or via the concrete 4 or the like so that a tensile force can be transmitted to or from the longitudinal bars 2 by the adhesive force of the concrete 4 or the like. Arranged.

  In FIG. 2A, only the representative horizontal stripe 5 is shown, but the end 33a of the intermediate rib 33 has an insertion hole 33b for inserting the horizontal stripe 5 as shown in FIG. A plurality of lower structures 1 are formed in the thickness direction (the bridge axis direction of the bridge girder 3). In FIG. 3, the insertion holes 33b are arranged in two rows in the thickness direction of the lower structure 1 according to the number of arrangement of the vertical bars 2 and are formed in a plurality of stages in the height direction. In some cases, three or more rows are arranged.

  In the example shown in FIG. 1 and FIG. 2, since the tensile force borne by the longitudinal bars 2 due to the bending moment transmitted from the bridge girder 3 is distributed in the width direction of the lower structure 1 that is the direction of the bridge axis, the intermediate ribs It is expected that the situation where the tensile force (stress) is concentrated in any of the regions partitioned by 33 is avoided, and the yield strength of the joint portion 30 is expected to increase due to the dispersion of the stress.

  The construction procedure will be described with reference to FIGS. 9- (a) to 9 (d) showing the construction process of the joint between the bridge girder 3 and the lower structure 1 shown in FIGS. FIG. 10 shows a completed state of the pedestrian bridge as the ramen bridge shown in FIG. 8 completed through the steps shown in FIG. The lower structure 1 is an abutment as described above.

  From the top end of the lower structure 1, as shown in FIG. 9A, a portion on the top end of the lower structure 1 where the end portions 32 a of both side ribs 32 of the bridge girder 3 and the end portions 33 a of the intermediate ribs 33 are placed. The vertical streak 2 protrudes for every area | region divided by the both-side rib 32 and the intermediate part rib 33 other than. The protruding length of the vertical bars 2 from the top end of the lower structure 1 is equal to or shorter than the distance from the top end of the lower structure 1 to the bottom surface of the floor slab portion 31 of the bridge girder 3. A prefabricated bridge girder 3 is suspended between the lower structures 1 and 1 and is erected as shown in FIG. 8, and as shown in FIG. 3 end portions are placed on the end portions 32 a of the both side ribs 32 and the end portions 33 a of the intermediate ribs 33.

  After placing the bridge girder 3, as shown in FIG. 9C, the horizontal bars 5 are arranged so as to pass through the insertion holes 33 b of the end portions 33 a of the intermediate ribs 33 and intersect with the vertical bars 2. The end portions on both sides of the horizontal stripe 5 are fixed to the end portions 32 a of the both side ribs 32.

  For example, the end of the horizontal stripe 5 is inserted into a fixing hole 32b which is formed from the end 32a of the both-side rib 32 from the intermediate rib 33 side or formed through the end 32a. The fixing hole 32b is fixed by filling with a filler such as mortar or adhesive. At least one of the fixing holes 32b, 32b of the both side ribs 32, 32 on both sides of the floor slab 31 is formed through the end portion 32a, so that the lateral stripe 5 is fixed to the fixing hole from the outside in the thickness direction of the both side ribs 32. It can be inserted into 32b and placed.

  After arranging the horizontal bars 5, the concrete is made for each region divided by the end portions 32 a of the both side ribs 32 and the end portions 33 a of the intermediate ribs 33 in a state where the barrier plates are arranged on both sides in the thickness direction of the lower structure 1. 4 or the like is filled (placed), and the vertical bars 2 and the horizontal bars 5 are embedded in the concrete 4 or the like. The filling of the concrete 4 or the like completes the joining of the bridge girder 3 and the lower structure 1, and the ramen bridge (pedestrian bridge) shown in FIG. 10 is completed.

  4 and 5, the intermediate rib 33 in FIG. 1 is formed from the bridge axial direction intermediate portion side of the bridge girder 3 to the front of the joint portion 30 on the lower structure 1, and on the top end of the lower structure 1, ie, the joint portion 30. A lateral girder portion 34 facing the width direction of the floor slab portion 31 is formed between the both side ribs 32, 32 in the region of FIG. An example of joining of the bridge girder 3 with the lower structure 1 is shown. The intermediate rib 33 is formed so as to protrude from the side surface of the cross beam portion 34 on the intermediate portion side of the bridge girder 3 in the bridge axis direction, and is integrated with the cross beam portion 34.

  The cross beam portion 34 is formed together with the floor slab portion 31, the side ribs 32, and the intermediate rib 33 when the bridge girder 3 is manufactured, and is integrated with the floor slab portion 31. Is formed with an insertion hole 34 a into which the vertical bar 2 is inserted, and the vertical bar 2 is inserted into the insertion hole 34 a when the bridge girder 3 is placed on the lower structure 1. After the bridge girder 3 is placed in the insertion hole 34a, the vertical bars 2 are fixed to the horizontal girder part 34 by filling with a filler such as mortar and adhesive. The insertion hole 34a is formed by, for example, embedding a cylindrical part such as a sleeve 34b in the concrete 4 or the like constituting the cross girder 34 when the bridge girder 3 is manufactured.

  In the example of FIG. 4, a vertical structure 34c is fixed to the side of the floor slab 31 such as a sleeve 34b constituting the insertion hole 34a by being welded or the like, so that the lower structure is formed in the insertion hole 34a. When one vertical bar 2 is inserted, both vertical bars 2 and 34c are connected (connected) via the sleeve 34b. In this case, the length of the sleeve 34b (depth of the insertion hole 34a) and the protruding length of the vertical stripe 2 protruding from the lower structure 1 are reduced, and the length of the vertical stripe 34c is relatively increased. Thus, when the bridge girder 3 is dropped onto the lower structure 1, it is possible to facilitate the insertion of the vertical bars 2 into the insertion hole 34a.

  In the example of FIG. 4, the horizontal stripe 5 in the example of FIGS. 1 and 2 can be embedded in advance in the inside of the cross beam portion 34 in accordance with the insertion position of the vertical stripe 2, that is, the formation position of the insertion hole 34 a. The bending moment generated in the bridge girder 3 due to the embedding of the horizontal bars 5 can be distributed in the width direction through the horizontal bars 5.

  FIG. 6 shows that the concrete 4 or the like is filled (placed) after the bridge girder 3 is installed in a section between the ribs 32, 32 of the bridge girder 3 and at least the end portion of the floor slab 31 including the joint 30 on the lower structure 1. An example of joining when the bridge girder 3 is joined to the lower structure 1 is shown. In this example, the concrete 4 or the like is sandwiched between the ribs 32 and 32 on the cross section when the bridge girder 3 is viewed in the width direction and over the section where the intermediate rib 33 is formed in the example shown in FIG. Will be placed on site at the site. Of the entire concrete 4 or the like, the portion present at the joint 30 corresponds to the cross beam portion 34 in the example shown in FIG.

  In the example of FIG. 6, only the ribs 32 and 32 on both sides serve as a formwork (dam plate) for placing concrete 4 or the like, and therefore, on the lower structure 1, one side in the thickness direction and three bridge girder bridges paired with it. A dam plate is disposed on the axially intermediate portion side, and concrete 4 or the like is placed in that state. In this example, concrete 4 or the like is integrated into the bridge girder 3 over the entire width of the bridge girder 3 and stiffens the bridge girder 3. Therefore, the rigidity and strength of the bridge girder 3 after joining to the lower structure 1 are shown in FIGS. There are advantages over the examples.

  Also in the example of FIG. 6, the bending that occurs in the bridge girder 3 by arranging the horizontal bars 5 in the example of FIGS. 1 and 2 in the portion corresponding to the joint 30 (the horizontal girder part 34) of the concrete 4 or the like. The effect of dispersing the moment in the width direction of the bridge girder 3 can be obtained.

1 ... substructure, 2 ... longitudinal bars,
3 ... Bridge girder, 30 ... Joint, 31 ... Floor slab,
32 …… Ribs on both sides, 32a …… End, 32b …… Fixing hole,
33: Intermediate rib, 33a: End, 33b: Insertion hole,
34 ... Cross beam part, 34a ... Insertion hole, 34b ... Sleeve, 34c ... Longitudinal muscle, 35 ... Tension material,
4 …… Concrete or mortar,
5: Horizontal stripes.

Claims (4)

It is a joint structure of a bridge girder made of precast concrete that is installed on an adjacent lower structure and is rigidly joined to the lower structure at both ends, and the lower structure,
The bridge girder includes a floor slab portion, and at least a lower side of both sides in the width direction of the floor slab portion, and both side ribs projecting toward the bridge axis direction of the floor slab portion, from the top end of the lower structure Has a protruding vertical line,
The bridge girder is placed on the top end of the lower structure on the both side ribs, and the vertical bars of the lower structure are arranged between the side ribs, and the vertical bars are embedded between the side ribs. Or the mortar is integrated and the bridge girder is joined to the substructure ,
An intermediate rib that faces the bridge axis direction of the floor slab in a section that includes a region on the top end of the lower structure, at least near the end of the floor slab, between the side ribs below the floor slab Projecting, and the vertical bars of the lower structure are arranged in the concrete or mortar other than the intermediate ribs,
A bridge girder that is arranged perpendicularly to the longitudinal bars in a portion located on the top end of the lower structure, and transverse bars fixed to the both side ribs pass through the intermediate ribs in the width direction. And joint structure of the substructure. A cross beam portion made of concrete or mortar that is integrated between the ribs in the width direction of the floor slab portion in a region on the top edge of the lower structure between the ribs on the lower side of the floor slab portion. The joint structure of the bridge girder and the lower structure according to claim 1 , wherein the vertical bars of the lower structure are inserted and embedded in the horizontal girder part. Ago Kiyuka plate portion and the both side ribs and the intermediate ribs that are adjacent in the width direction, and the concrete or mortar is filled between the intermediate ribs, the longitudinal muscle of the lower structure to the concrete or mortar, The joint structure of the bridge girder and the lower structure according to claim 1 , wherein Concrete or mortar is filled in a section near the end of the floor slab including at least the region on the top end of the lower structure between the ribs on the lower side of the floor slab, and the concrete or mortar The junction structure of the bridge girder and the lower structure according to any one of claims 1 to 3 , wherein the vertical bars of the lower structure are embedded.

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