JP5243998B2 - Bridge superstructure and construction method of bridge superstructure - Google Patents

Description

  The present invention relates to a bridge superstructure and a method for constructing a bridge superstructure.

  Patent Document 1 discloses a bridge upper structure made of concrete, which includes a plurality of main girders arranged in a direction perpendicular to the bridge axis and a horizontal girder connecting adjacent main girders. Yes. In this bridge superstructure, although the main girder has a solid I-shaped cross section, high-strength fiber reinforced concrete is used, so the main girder is lighter than when using ordinary concrete. Can do.

  Patent Document 2 discloses a box-shaped main girder formed by closing an opening of a segment having an inverted U-shaped cross section with a bottom plate. The weight can also be reduced by using a box-shaped main girder.

JP 2002-021023 A JP 2008-285906 A

  Although the main girder can be made lighter, it is possible to reduce the weight of the main girder. However, the inner mold that forms the hollow part looks like it floats on the concrete, so measures to prevent the inner mold from lifting. It is necessary to take. Furthermore, since the restraining force accompanying the shrinkage of the concrete acts on the inner mold, there is a possibility that the demolding operation becomes difficult.

  With the box-shaped main girder disclosed in Patent Document 2, the problem of buoyancy and restraint force is solved, but the work of combining the segment and the bottom slab is required, so that time is required for assembly work and joining work. Resulting in.

  From such a viewpoint, the present invention is a bridge superstructure of a type in which a plurality of concrete main girders are arranged side by side, and can be reduced in weight without using a box-shaped concrete main girder. It is an object to provide an upper structure, and further to provide a construction method thereof.

A bridge superstructure according to the present invention that solves the above-described problems includes a plurality of concrete main girders arranged side by side in a direction perpendicular to the bridge axis, and a horizontal girder that connects the main girders adjacent in the direction perpendicular to the bridge axis. a bridge superstructure, the main girder is to have a groove shape of the open cross-sectional shape which opens downward, the interposition portion includes a pair of webs facing the bridge axis perpendicular, the upper end portion of the web It is characterized by having a floor slab part that connects each other .

  In the bridge superstructure according to the present invention, weight reduction is realized by providing a groove-shaped portion having an open cross-sectional shape in a concrete main girder. According to the present invention, since at least a part of the main girder has an open cross-sectional shape, it is possible to simply and quickly perform the installation / demolding work of the inner mold. That is, according to the present invention, the main girder can be easily and quickly manufactured as compared with a box-type main girder whose entire length is a closed cross-sectional shape.

In addition, when an external force (for example, seismic force) in the direction perpendicular to the bridge axis acts on the main girder, a rotation moment (hereinafter referred to as “falling moment”) that causes the main girder to fall (side down) is generated. In the present invention, since the main girders adjacent to each other in the direction perpendicular to the bridge axis are connected and integrated with each other with a horizontal girder, the resistance force against the overturning moment can be increased. In particular, in the present invention, since the solid portion is connected to the end of the groove portion in the bridge axis direction, and the cross beam is connected to the solid portion , the main beam and the cross beam are integrated. the rigidity of the structure formed Te Ri is Do and high, therefore, it is possible to further enhance the resistance to overturning moments.

  Although there is no restriction | limiting in the position, the number, etc. of a solid part, it is good to provide the said solid part in each of the both ends of the bridge axis direction of the said main girder, and to install a support below the said solid part.

  A transverse tension member penetrating the cross beam and the solid portion in a direction perpendicular to the bridge axis is provided, and an end face of the transverse beam in the direction perpendicular to the bridge axis is formed by the tension applied to the transverse tension member. You may crimp on the side. If it does in this way, it will become possible to unify a main girder and a cross beam firmly. The end face of the cross beam may be directly crimped to the side surface of the solid part, or may be indirectly crimped via a filler or a plate.

  A longitudinal tension material penetrating the main girder in the direction of the bridge axis may be provided, and prestress may be imparted to the main girder by a tension force imparted to the longitudinal tension material. In this way, it is possible to increase the span of the main girder.

  A plurality of partition walls arranged at intervals in the bridge axis direction may be provided in the internal space of the groove-shaped portion. In this way, the torsional rigidity of the main girder around the bridge axis is improved.

  In addition, when a partition is provided in the groove-shaped portion, the longitudinal tension member may be routed so as to penetrate each partition. If it does in this way, a some partition will become a deflection | deviation part (deviator) of a longitudinal tension material.

  The shape of the cross beam is not limited, but if a cross beam having a tubular shape is used, it is possible to further reduce the weight of the bridge superstructure.

The method for constructing a bridge superstructure according to the present invention that solves the above-described problem includes a pair of webs facing in a direction perpendicular to the bridge axis and a floor slab that connects the upper ends of the webs, and an open section that opens downward A plurality of concrete main girders having a groove portion having a shape and having a solid portion connected to an end portion in the bridge axis direction of the groove shape portion between two adjacent bridge piers in the bridge axis direction. After being installed, the solid portions of the adjacent main girders are connected with a horizontal girder on the pier.

  In short, the method for constructing the bridge superstructure according to the present invention is such that, after a plurality of main girders are individually installed, adjacent main girders on the bridge pier are connected with horizontal girders. When constructing a structure formed by integrating the main girder and the horizontal girder together between the piers, a vast work space and a large heavy machine are required. According to the present invention, a vast work space is required. It is possible to build the bridge superstructure without using heavy machinery or large heavy machinery.

According to the bridge superstructure according to the present invention, it is possible to reduce the weight without using a box-shaped concrete main girder.
Moreover, according to the construction method of the bridge superstructure according to the present invention, it is possible to construct the bridge superstructure without using a large work space or a large heavy machine.

It is a figure which shows the bridge | bridging superstructure which concerns on embodiment of this invention, Comprising: (a) is a top view, (b) is 1B-1B sectional drawing of (a). (A) is 2A-2A sectional drawing of Fig.1 (a), (b) is the elements on larger scale of FIG.1 (b). (A) is 3A-3A sectional drawing of FIG.1 (b), (b) is 3B-3B sectional drawing similarly, (c) is 3C-3C sectional drawing similarly. It is a schematic diagram of the work yard used when constructing a bridge superstructure, (a) is a top view and (b) is an end view. It is a schematic diagram of the equipment used when constructing a bridge superstructure, (a) is a top view and (b) is an end view. (A)-(c) is a side view which shows the construction procedure of the bridge | bridging superstructure which concerns on embodiment of this invention. (A), (b) is a top view which shows the process following (c) of FIG. It is a figure for demonstrating the advantage of the bridge superstructure which concerns on embodiment of this invention, Comprising: (a) is an end elevation of the bridge superstructure which concerns on embodiment of this invention, (b) is the bridge upper part which concerns on a comparative example 1 is an end view of a structure.

  As shown in FIG. 1, the bridge superstructure K according to the embodiment of the present invention constitutes a track in a double track curve section of a straddle-type monorail, and is made of a plurality of concrete arranged side by side in a direction perpendicular to the bridge axis. Main girder 1, 1 and longitudinal tension members 2, 2,... For applying prestress to each main girder 1, horizontal girder 3, 3 connecting main girder 1, 1 adjacent to each other in the direction perpendicular to the bridge axis, and main girder , 1, 1 and transverse girder 2 are connected to each other.

  The main girder 1 is a straddle-type monorail track girder (running girder), which is gently curved in accordance with the planar alignment of the curve section. Since the width dimension of the main girder 1 is defined by the width dimension of the traveling wheel of the monorail vehicle, etc., in order to increase the cross-sectional secondary moment of the main girder 1, while keeping the width dimension of the main girder 1 constant, It is necessary to increase the height of the main girder 1. The main girder 1 of this embodiment assumes a case where the distance between fulcrums is set to 20 m or more, and has a girder height of three times or more the width dimension as shown in FIG.

  Incidentally, the upper surface of the main girder 1 is a traveling surface on which traveling wheels of a monorail vehicle travel. A mounting groove D having a trapezoidal cross section is formed continuously on the side surface of the main girder 1 in the bridge axis direction. An unillustrated train line (an overhead line for supplying electric power to the monorail vehicle) is attached to the attachment groove D. Of the side surfaces of the main girder 1, the side surface U positioned above the mounting groove D is a guide surface on which a guide wheel (not shown) of the monorail vehicle travels, and the side surface L positioned below the mounting groove D is a monorail. It becomes a stable surface on which a stable wheel (not shown) of the vehicle travels.

  As shown in FIG. 1B, the main girder 1 includes a groove portion 11 having an open cross-sectional shape that opens downward, and a solid portion 12 that is connected to the end portion of the groove portion 11 in the bridge axis direction. , 12 and a plurality of partition walls 13, 13,... Arranged in parallel at intervals in the bridge axis direction.

  As shown in FIGS. 3A and 3B, the groove portion 11 includes a pair of webs 1a, 1a facing each other in the direction perpendicular to the bridge axis, and a floor slab portion 1b that connects the upper ends of the webs 1a, 1a. And has an inverted U-shaped cross section. The web 1a has a generally flat plate shape. The floor slab portion 1b has a flat plate shape and is integrally formed with the left and right webs 1a, 1a.

  The solid part 12 shown in FIG. 1B is a part that exhibits a solid block shape, and is provided at each of both ends of the main girder 1 in the bridge axis direction. The solid part 12 of the present embodiment is formed at a position corresponding to the support S installed on the pier P (directly above the support S). The solid portion 12 is formed integrally with the groove portion 11.

  As shown in FIGS. 2B and 3C, the solid portion 12 is formed with a plurality of vertical through holes 1c, 1c,... And a plurality of horizontal through holes 1d, 1d,. Has been.

  The vertical through holes 1c, 1c, ... are provided corresponding to the number and arrangement of the plurality of vertical tension members 2, 2, ..., and penetrate the solid portion 12 in the bridge axis direction. The vertical tension material 2 is inserted through the vertical through hole 1c. As shown in FIG. 3C, in the present embodiment, one vertical through hole 1c is formed in the upper part of the solid part 12, and two each in the middle part and the lower part of the solid part 12. Although the vertical through holes 1c and 1c are formed, the position and number of the vertical through holes 1c are not limited.

  The horizontal through holes 1d, 1d,... Are provided corresponding to the plurality of lateral tension members 4, 4,..., And penetrate the lower part of the solid portion 12 in the direction perpendicular to the bridge axis. The lateral tension member 4 is inserted into the lateral through hole 1d. The horizontal through hole 1d is formed above or below the vertical through hole 1c so as not to interfere with the vertical through hole 1c, and three-dimensionally intersects with the vertical through hole 1c. As shown in FIG. 2B, in the present embodiment, the horizontal through holes 1d, 1d,... Are formed in the rectangular frame region in accordance with the cross-sectional shape of the cross beam 3 (see FIG. 2A). However, it is not intended to limit the position and number of the horizontal through holes 1d.

  A partition wall 13 shown in FIG. 1 (b) is a flat wall body that increases the torsional rigidity of the groove portion 11 and also functions as a deflecting portion (deviator) of the longitudinal tension member 2. It arrange | positions so that a groove-shaped internal space may be partitioned off.

  As shown in FIG. 3B, the partition wall 13 connects the left and right webs 1 a and 1 a in the internal space of the groove portion 11. The partition wall 13 is formed with a plurality of vertical through holes 1e, 1e,. The plurality of longitudinal through holes 1e, 1e,... Are provided corresponding to the plurality of longitudinal tension members 2, 2,..., And as shown in FIG. It penetrates in the wall thickness direction). The longitudinal tension material 2 is inserted through the through hole 1e.

  When the partition walls 13 are arranged at appropriate intervals, the torsional shear stress acting on the web 1a and the floor slab portion 1b due to the torsional rotational force around the bridge axis is reduced to 1/5 to 1 / It becomes possible to reduce to 10.

The main girder 1 of this embodiment is formed of ultra high strength fiber reinforced concrete.
As the ultra high strength fiber reinforced concrete forming the main girder 1, the compression strength of the cured body is in the range of 150 to 200 N / mm ² , the bending tensile strength is in the range of 25 to 45 N / mm ² , and It is desirable to use one having a split tensile strength in the range of 10 to 25 N / mm ² . Such an ultra-high-strength fiber reinforced concrete has a higher elastic modulus than a normal ultra-high-strength fiber reinforced concrete (for example, E = about 50 to 55 kN / mm ² ), so that the cross-sectional area of the main girder 1 The bending rigidity can be increased without increasing the (second moment of section). Moreover, since the tensile resistance force with respect to the tensile force can be expected by the mixed fibers, the reinforcing bars can be omitted and the thickness of the web 1a and the floor slab portion 1b can be reduced.

  The ultra-high-strength fiber reinforced concrete having the above-described strength is, for example, a high-performance water reducing agent and water mixed in a powder containing cement, a pozzolanic reaction particle, and an aggregate having a maximum particle size of 2.5 mm or less. It can be obtained by mixing 1 to 4% by volume of fibers having a shape with a diameter of 0.1 to 0.3 mm and a length of 10 to 30 mm in the cement matrix obtained. Here, the pozzolanic reaction particles are particles made of, for example, silica fume, fly ash, blast furnace slag, a compound selected from kaolin derivatives, precipitated silica, volcanic ash, silica sol, and the like. Moreover, although there is no restriction | limiting in particular in the material of a fiber, Considering the adhesiveness with concrete, the ease of material procurement, etc., it is desirable to use steel.

  In order to manufacture the main girder 1, first, the above-described ultra-high-strength fiber reinforced concrete kneaded with various materials is used to form an inner mold frame for molding the inner surface of the main girder 1 and an outer mold for molding the outer surface. Place between the frame. In this embodiment, since there is no portion (hollow part) having a closed cross section, even if ultra high strength fiber reinforced concrete is placed between the inner mold frame and the outer mold frame, the inner mold There is no buoyancy in the frame. That is, since the groove 11 of the main girder 1 is opened, the inner mold that forms the inner surface of the main girder 1 does not become a floating mold, so that the hollow part is formed over the entire length. Compared with the case of manufacturing a box girder having a cross-sectional shape, it is possible to make the inner mold frame, a jig for fixing the inner frame, and the like light.

  Incidentally, the above-described ultra-high-strength fiber reinforced concrete has a high self-filling property, so that compaction by a vibrator or the like can be omitted or the scale can be reduced. If compaction by a vibrator or the like is simplified, the load applied to the inner mold frame and the outer mold frame becomes small. Therefore, even when the main girder 1 requires high dimensional accuracy, It is possible to make the outer mold frame light, and it is possible to suppress an increase in manufacturing cost.

  When the ultra-high-strength fiber reinforced concrete cast between the inner mold frame and the outer mold frame reaches the demolding strength, the inner mold frame and the outer mold frame are demolded. Ultra-high-strength fiber reinforced concrete is self-shrinking in the process of curing, so when producing a box girder with a hollow part formed over its entire length, its demolding is caused by a large restraining force acting on the inner mold. Although the work is difficult, in this embodiment, since the lower surface of the groove 11 of the main girder 1 is opened, it is easy to remove the inner mold, and thus the inner mold is easy. It can be reused.

  After removing the inner and outer molds, heat curing is performed. When heat curing is performed, the free lime in the cement and the silica and alumina of the pozzolanic reaction particles combine to form a stable and hard substance at an early stage, and the cement matrix structure becomes denser. , And dry cracks are less likely to occur.

  A longitudinal tension member 2 shown in FIG. 1B gives prestress to the main girder 1. Prestress is introduced by a post-tension method. The longitudinal tension member 2 penetrates the main girder 1 in the bridge axis direction and is applied to the end surface (end surface of the solid portion 12) of the main girder 1 in the bridge axis direction in a state where tension (tensile force) is applied. It has been established. The longitudinal tension material 2 consists of PC steel materials, such as a strand from PC steel, for example. The vertical tension member 2 is a so-called external cable, and is inserted into the vertical through hole 1c of the solid portion 12 and the vertical through hole 1e of the partition wall 13 as shown in FIG. It is routed while being exposed in the internal space of the groove-shaped portion 11.

  As shown in FIG. 1B, the longitudinal alignment of the longitudinal tension member 2 has a shape that protrudes downward, and is inclined downward from the longitudinal end of the main girder 1 toward the center. The central part of the main beam 1 is parallel to the lower edge of the main beam 1. In this way, since prestress can be introduced in a manner corresponding to the distribution of the longitudinal bending moment generated in the main girder 1 due to the vertical load, the bending strength of the main girder 1 is improved. In addition, the plane alignment of the longitudinal tension member 2 is not shown in the drawing, but has a shape along the plane alignment of the central axis of the main beam 1. If it does in this way, generation | occurrence | production of the lateral bending moment resulting from the tension | tensile_strength of the longitudinal tension material 2 can be suppressed. In addition, since several partition 13, 13, ... functions as a deflection | deviation part (deviator) of the longitudinal tension material 2, even if tension force is given to the longitudinal tension material 2, the linearity of illustration is maintained.

  As shown in FIG. 1A, the cross beam 3 is interposed between the ends of the main beams 1 and 1. The cross girder 3 of this embodiment is arrange | positioned just above the bridge pier P, and has connected the lower parts of the solid parts 12 and 12, as shown to (c) of FIG. Although not shown, a cement-based filler is interposed between the end face of the cross beam 3 and the side face of the solid portion 12. The filler may be omitted, and the end face of the cross beam 3 may be brought into direct contact with the side face of the solid portion 12.

  As shown in FIG. 2A, the cross beam 3 of the present embodiment is a concrete member having a hollow cross section and has a rectangular tube shape. The cross beam 3 is also formed of ultra high strength fiber reinforced concrete. A plurality of lateral through holes 3a, 3a,... Are formed in the outer shell portion of the cross beam 3. The horizontal through holes 3a, 3a,... Are provided corresponding to the plurality of lateral tension members 4, 4,..., And penetrate the outer shell portion of the cross beam 3 in the direction perpendicular to the bridge axis.

  As shown in FIG. 3 (c), the lateral tension member 4 passes through the left and right main girders 1, 1 and the lateral girder 3 in the direction perpendicular to the bridge axis, and is solid in a state where tension is applied. It is fixed to the outer side surface of the portion 12 (the side surface opposite to the side surface to which the cross beam 3 is connected). The lateral tension member 4 of the present embodiment is made of, for example, a PC steel material such as a PC steel rod, and is inserted into the lateral through hole 1d of the solid portion 12 and the lateral through hole 3a of the cross beam 3.

  In order to construct the bridge superstructure K configured as described above, as shown in FIG. 1 (a), two main girders 1, 1 are provided between two bridge piers P adjacent to each other in the bridge axis direction. Next, the adjacent main girders 1 and 1 may be connected by the horizontal girders 3 and 3 on the pier P.

  More specifically, first, the main girders 1 and 1 are installed between the two piers P and P, and the horizontal girders 3 and 3 are arranged between the left and right main girders 1 and 1. The main girder 1 and the horizontal girder 3 are temporarily placed on a temporary receiving member (not shown) provided on the bridge pier P, and a gap of about several centimeters (between the side surface of the main girder 1 and the end surface of the horizontal girder 3 ( (Not shown) is secured. Before the main girder 1 is installed between the piers P and P, the longitudinal tension member 2 (see FIG. 1B) is routed to the main girder 1 on the manufacturing factory of the main girder 1 or on the pier 51. Introduce pre-stress.

  Subsequently, as shown in FIG. 3C, lateral tension members 4, 4 are provided through the solid portions 12, 12 of the left and right main girders 1, 1 and the transverse girder 3, A mold (not shown) is installed around the gap secured between the end of the cross beam 3 and a filler (for example, cement filler) is filled in the gap. When the filler has hardened to a predetermined strength, tension is applied to the transverse tension members 4 and 4, and the main girders 1 and 1 and the transverse girders 3 are connected. Thereafter, when the main girder 1 and the cross girder 3 supported by the temporary support member are replaced with the support S provided on the pier P, the bridge superstructure K is completed.

  Here, the procedure for connecting a plurality of bridge superstructures K, K,... Will be described in detail with reference mainly to FIGS.

  As shown in FIG. 4, first, a plurality of piers P, P,... Are constructed at a planned construction position of the bridge, and a pier 51 serving as a work yard is constructed in an area adjacent to the planned construction position of the bridge. In addition, materials and equipment such as cranes 52 and 52 are installed on the pier 51.

  Subsequently, the bridge upper structures K and K for two spans are constructed in an area adjacent to the pier 51 using the cranes 52 and 52. In the following description, the bridge upper structure K constructed on the side of the pier 51 may be referred to as “existing bridge upper structure K”.

  Thereafter, as shown in FIG. 5, the carts 6 and 6 and the erection device 7 are installed on the existing main girders 1 and 1. The trolleys 6 and 6 carry the main girder 1 ′ to be erected in the next process (hereinafter may be referred to as “new main girder 1 ′”) to the erection device 7, and the erection device 7 is newly installed. The main girder 1 'is transported to the planned installation position.

  Although there is no restriction | limiting in the structure of the trolley | bogie 6, what is illustrated is constructed between the existing main girders 1 and 1, and it travels on the existing main girders 1 and 1 in a bridge axis direction. The cart 6 of the present embodiment travels on the main girders 1 and 1 by being pulled by unillustrated pulling means provided on the existing main girders 1 and 1. Note that a power source such as a motor may be mounted on the cart 6 so that the cart 6 can be self-propelled.

  Although the construction of the erection device 7 is not limited, the illustrated one is a pair of left and right erection beams 71, 71, bridge cranes 72, 72 that run on the erection beams 71, 71, and a lower part of the erection beam 71. A traveling platform 73 (see FIG. 5B and FIG. 6A) is provided. The installation girder 71 is a truss structure girder having a length of two spans, and a portion corresponding to the length of one span is disposed above the existing main girder 1, and the remaining one span. The portion corresponding to the length extends along the planned construction position of the newly installed main girder 1 ′. The tip of the erection beam 71 is supported by the pier P (see FIG. 6A). The bridge-type crane 72 is installed between the installation girders 71 and 71, and travels in the direction of the bridge axis while the main girder 1 'is suspended. The erection device 7 of the present embodiment runs on the existing main girders 1 and 1 using a motor mounted on the erection device 7 as a power source. Note that traction means (not shown) may be provided on the existing main girders 1, 1 and the like, and the erection device 7 may be pulled.

  Subsequently, the newly installed main girder 1 ′ is placed on the carts 6 and 6 using the cranes 52 and 52. Thereafter, as shown in FIG. 6A, the main girder 1 ′ is moved toward the construction device 7. As shown in FIG. 6 (b), when the newly installed main girder 1 'is moved to the inside of the erection device 7, the main girder 1' is suspended by the bridge cranes 72, 72, and the main girder 1 'is moved to the carriage. 6 and 6 (see FIG. 5 (a)).

  Subsequently, the bridge cranes 72 and 72 are moved toward the distal end side of the erection beam 71. When the new main girder 1 ′ reaches above the planned installation position, as shown in FIG. 6 (c), the main girder 1 ′ is lowered, and between the piers P and P provided at the planned installation position. Temporarily place the main beam 1 '. Since the main girder 1 'has a length corresponding to one span, a vent or the like for supporting an intermediate portion of the main girder 1' is not necessary.

  Thereafter, as shown in FIG. 7A, the newly installed main girder 1 'is moved in the direction perpendicular to the bridge axis and installed on the support S (see FIG. 1B). In FIG. 7, illustration of the erection device 7 is omitted.

  Next, as shown in FIG. 7B, another main beam 1 'is installed next to the main beam 1'. The installation procedure of the second main girder 1 'is the same as that described above. After that, when the carriage 6 is used to transport the cross beams 3 'and 3' onto the bridge pier P and the ends of the main beams 1 'and 1' are connected to each other with the cross beams 3 'and 3' on the bridge P. The new bridge superstructure K 'is completed. Since only the ends of the main girders 1 'and 1' need only be connected by the cross beam 3 ', it is not necessary to construct a vent, a working scaffold or the like in the center of the span. If a work space cannot be secured on the pier P, a cantilevered scaffold may be attached to the pier P.

  When the above operations are repeated, a plurality of bridge superstructures K, K,... Can be connected in the bridge axis direction.

  As described above, in the bridge superstructure K, the main girder 1 is provided with the groove-shaped portion 11 having an open cross-sectional shape, and the horizontal girder 3 is hollowed to realize weight reduction. When the bridge superstructure K becomes lighter, the load acting on the bridge substructure such as the pier P becomes smaller, so it is possible to reduce the scale of the bridge substructure and thus reduce the total construction cost of the bridge work. Is possible.

  Moreover, in this embodiment, the main girder 1 is made of ultra-high-strength ultra-high-strength fiber reinforced concrete that can be expected to have tensile resistance, and the longitudinal tension member 2 routed to the main girder 1 is an “outer cable”. Therefore, it is possible to omit or reduce the reinforcing bars and PC steel materials embedded in the web 1a of the main beam 1. If the reinforcing bars are omitted, it is not necessary to secure the cover, so that the main girder 1 can be thinned, and the bridge superstructure K can be further reduced in weight.

  Further, according to the bridge superstructure K, most of the main girder 1 has an open cross-sectional shape, so that it is possible to easily and quickly perform the installation / demolding work of the inner mold. That is, according to the main girder 1, the main girder 1 can be easily and quickly manufactured as compared with a box-shaped main girder whose entire length is a closed cross-sectional shape.

  According to the bridge superstructure K, the longitudinal tension member 2 is routed so as to penetrate the partition wall 13, and the partition wall 13 is used as a deflection unit (deviator) of the longitudinal tension member 2. Can be omitted or reduced. In addition, since prestress is given to the main girder 1, it becomes possible to achieve a long span of the main girder 1.

  According to the bridge superstructure K, the end face in the direction perpendicular to the bridge axis of the cross beam 3 is crimped to the side surface of the solid part 12 by the tension applied to the horizontal tension member 4. And come to be firmly integrated.

  In addition to the fulcrum reaction force, the supporting force associated with fixing the longitudinal tension member 2 and the lateral tension member 4 acts on the end of the main girder 1 in the longitudinal direction. Then, since the solid solid parts 12 and 12 are formed at both ends of the main girder 1, the fulcrum reaction force and the support pressure can be stably received.

  In addition, as shown in FIG. 8A, when an external force H in the direction perpendicular to the bridge axis acts on the main girders 1 and 1, a tipping moment is generated in the main girder 1, but the bridge superstructure K Then, since the main girders 1 and 1 adjacent to each other in the direction perpendicular to the bridge axis are connected and integrated with the cross beam 3, the resistance force against the overturning moment can be increased. That is, as shown in FIG. 8B, when an external force H is applied to the main girder 100 erected independently, the fulcrum reaction forces V1 ′ and V2 ′ acting on the support S resist the overturning moment. However, since the separation distance (arm length of the resistance moment) of the fulcrum reaction forces V1 ′ and V2 ′ is small, the fulcrum reaction forces V1 ′ and V2 ′ are large, and the weight of the main girder 100 is taken into consideration. However, a large pulling force acts on the anchor bolt of the support S. In order to face a large pulling force, the support S needs to be heavy and large-scale, but it is not economical.

  On the other hand, according to the bridge superstructure K according to this embodiment in which the main girders 1 and 1 are connected by the horizontal girders 3, as shown in FIG. The fulcrum reaction force V1 and the fulcrum reaction force V2 acting on the support S of the other main girder 1 resist the overturning moment, but the separation distance (arm length of the resistance moment) of the fulcrum reaction forces V1 and V2 is large. Therefore, when the fulcrum reaction forces V1 and V2 are reduced and the weights of the main girders 1 and 1 are taken into consideration, the pulling force acting on the anchor bolt of the support S becomes zero or extremely small. That is, according to the bridge upper structure K, it is possible to make the support S light and have a small scale, so that it is possible to reduce the cost.

  Furthermore, in the bridge superstructure K, the main girder 1 and the cross girder 3 are formed of ultra-high strength fiber reinforced concrete with a dense structure, so even under severe natural conditions where salt damage is a concern, 100 years No maintenance is required for orders.

  In the straddle-type monorail track girder, not only the traveling surface on which the traveling wheels of the monorail vehicle travel, but also the guide surface on which the guide wheels travel and the stable surface on which the stable wheels travel have high dimensional accuracy. Where smoothness is required, as in the present embodiment, when the main girder 1 is formed from self-filling high ultra-high strength fiber reinforced concrete, simply increasing the dimensional accuracy and smoothness of the mold, It becomes possible to improve the dimensional accuracy and smoothness of the running surface and the like.

  In addition, in the present embodiment, since the upper surface of the main girder 1 made of ultra-high-strength fiber reinforced concrete is the running surface, the friction coefficient can be made 0.6 or more, and therefore against the slip of a monorail vehicle Safety is high.

  Incidentally, in the conventional prestressed concrete track girder, it was necessary to set the distance between fulcrums to about 20 m or less, but according to the bridge superstructure K, it can be expanded to about 90 to 100 (m). If the distance between the fulcrum of the track girder can be increased, the number of piers P can be reduced, so that the construction period and cost can be reduced.

  Further, when the plurality of main girders 1 and 1 are individually installed as in the method for constructing the bridge superstructure K according to the present embodiment, the bridge superstructure K can be obtained without using a large work space and large heavy machinery. It becomes possible to build. In addition, according to the method for constructing the bridge superstructure K according to the present embodiment, it is not necessary to construct a vent, a work scaffold, or the like in the center portion of the span, so traffic regulation to the existing traffic road that passes below the planned construction position Etc. can be stopped on a small scale.

  In addition, the concrete main girder 1 is less likely to buckle than the steel main girder, and thus a stable structure can be obtained without arranging the cross girder 3 in the middle of the main girder 1 and 1. In the case where the plane alignment of the girder has an S-shape or when the distance between the fulcrums is large, the intermediate portions of the main girders 1 and 1 may be connected by the horizontal girder 3.

  Further, in the present embodiment, the main girder 1 integrally formed by integral driving is illustrated, but the main girder 1 having a length corresponding to one span cannot be integrally formed due to restrictions of factory equipment and transportation vehicles. Although not shown in the figure, it may be divided into a plurality of segments and integrated in a work yard near the site. The procedure after the integration is the same as the procedure shown in FIGS.

  When the main girder 1 is constructed by integrating a plurality of segments, each segment is preferably manufactured by match casting. When the segments are manufactured by match casting, the segments may be connected by a joining method such as a dry joint method or a wet joint method. By the way, the dry joint method applies post tension to the longitudinal tension material that is routed so as to penetrate through multiple segments by applying epoxy resin etc. to the joint end surface of the segment and then sticking it to the joint end surface of other segments. It is a joining method that joins segments by introducing prestress in the method. In addition, the wet joint method has two segments facing each other with a gap of about several centimeters, and longitudinal tension members are routed so as to penetrate each segment. This is a joining method in which segments are joined by filling a cement-type filler in the mold form and introducing pre-stress by a post-tension method after the filler reaches a predetermined strength.

  In the present embodiment, the bridge superstructure K used as the track of the straddle-type monorail is illustrated, but it is needless to say that the bridge superstructure according to the present invention may be applied to a general railway bridge, a road bridge, and the like.

  In the present embodiment, the bridge superstructure K in the form of a simple beam constructed between the bridge piers P and P arranged at intervals in the bridge axis direction is exemplified, but the structure type of the bridge superstructure according to the present invention is limited. It is not the purpose. The present invention can also be applied to, for example, a bridge superstructure that is constructed on three or more piers (abutments) and designed as a continuous beam.

K Bridge superstructure 1 Main girder 11 Groove part 12 Solid part 13 Bulkhead 2 Longitudinal tension material 3 Lateral girder 4 Lateral tension material S Bearing P Pier

Claims (7)

A bridge superstructure comprising a plurality of concrete main girders arranged side by side in a direction perpendicular to the bridge axis and a horizontal girder connecting the main girders adjacent in the direction perpendicular to the bridge axis,
The main girder has a groove portion having an open cross-sectional shape that opens downward, and a solid portion that is connected to an end portion of the groove portion in the bridge axis direction ,
The cross beam is connected to the solid part;
The said groove-shaped part is provided with a pair of web which opposes a bridge axis orthogonal direction, and the floor slab part which connects the upper end parts of the said web, The bridge superstructure characterized by the above-mentioned. It comprises a lateral tension material that penetrates the cross beam and the solid part in a direction perpendicular to the bridge axis,
2. The bridge superstructure according to claim 1 , wherein an end surface of the cross beam in a direction perpendicular to the bridge axis is crimped to a side surface of the solid portion by a tension force applied to the lateral tension member. The solid portion is provided at each of both ends in the bridge axis direction of the main girder,
The bridge superstructure according to claim 1 or 2 , wherein a support is installed below the solid part. A longitudinal tension material penetrating the main girder in the direction of the bridge axis;
The bridge superstructure according to any one of claims 1 to 3 , wherein a prestress is applied to the main girder by a tension applied to the longitudinal tension member. In the internal space of the groove-shaped part, a plurality of partition walls arranged at intervals in the bridge axis direction are provided,
The longitudinal tension material penetrates the partition walls,
The bridge superstructure according to claim 4 , wherein each partition wall functions as a deflection portion for the longitudinal tension member. The bridge superstructure according to any one of claims 1 to 5 , wherein the cross beam has a cylindrical shape. It has a groove-shaped portion having an open cross-sectional shape that opens downward with a pair of webs facing in a direction perpendicular to the bridge axis and a floor slab portion that connects the upper ends of the webs, and the bridge-axis direction of the groove-shaped portion After placing a plurality of concrete main girders having a solid part continuously provided at the end of the bridge between two adjacent piers in the bridge axis direction, the middle of the adjacent main girders on the pier A construction method of the bridge superstructure characterized by connecting the real parts with horizontal beams.

Images