JP2019173269A - Method to construct concrete bridge girder with frame structure and temporary closure structure usable on this method - Google Patents

Abstract

To provide a method that can use constructed parts of a bridge girder as construction road when the concrete bridge girder with frame structure is constructed with cantilever overhang erection method.SOLUTION: A first lateral span part (8b) which is constructed earlier than a central span part (8a) located in the center of a frame structure part makes a connection of central span parts a horizontally force applicable temporary closure from after becoming a pin connection. After central closure is performed by rigid connection on the central span part, a second lateral span part (8c) which is constructed even later than that is center-closed, meanwhile, the first lateral span part is center-closed.SELECTED DRAWING: Figure 1

Description

  The present disclosure includes a method for laying a bridge girder of a concrete bridge having a ramen structure by a cantilever-type overhang construction method, and a temporary closing structure that can be used when the same method is applied to the erection of a box girder using a precast concrete segment. About.

  The cantilever overhanging construction method is one of the construction methods of concrete bridges. Bridge girders are constructed from each pier to both sides in the direction of the bridge axis. It is a method of connecting to each other.

  In many cases, the bridge girder is supported by the abutment and the pier via the support, but the maintenance cost of the support is relatively high. Therefore, in order to reduce the maintenance cost, a ramen structure in which the bridge girder is rigidly connected to the abutment or the pier may be adopted.

  In a concrete bridge having a rigid frame structure across multiple diameters, a large cross-sectional force is generated at the lower end of the lower structure due to temperature changes of the bridge girder, creep, drying shrinkage, and the like. In order to reduce this cross-sectional force, in the cantilever type overhang construction method, a horizontal force is applied to apply force in the direction of the bridge axis by a jack before rigidly connecting the overhanging portions facing each other (closing the center). (For example, Patent Documents 1 and 2).

JP 2010-242315 A JP 2017-53196 A

  When constructing a girder of a concrete bridge with a ramen structure that spans multiple spans by a cantilever-type overhang construction method, first the center is closed at the center of the ramen structure, and then the horizontal force and center of the side part are Closure takes place. In this case, the bridge girder cannot be connected to other parts until the central closure at the center of the ramen structure, so the existing part of the bridge girder could not be used as a construction road.

  In view of such problems, the present invention provides a method for using an existing part of a bridge girder as a construction road when a bridge girder of a concrete bridge having a ramen structure is constructed by a cantilever-type overhanging construction method, and An object of the present invention is to provide a temporary closing structure in the center between the spans.

  The method according to at least some embodiments of the present invention comprises three or more consecutive spans (8) spanned between two adjacent piers (4) or abutments (3) in a bridge girder (2). Each of the span portions in the ramen structure has a connecting portion (9) at a central position in the direction of the bridge axis, The span portion in the ramen structure is one or two central span portions (8b) located in the center of the ramen structure and one or more first span portions located in one of the central span portions in the bridge axis direction. The concrete bridge (1) including one lateral span (8a) and one or more second lateral spans (8c) located on the other side of the central span in the axial direction of the bridge. A method of erection of a bridge girder by a cantilever-type overhang construction method, Connecting the connecting portion of the first lateral span portion by a temporary closing that is capable of performing horizontal force afterward, and constructing the first lateral span portion, and rigid coupling Connecting the connecting portion of the central span portion by central closure by: building the central span portion; building the second lateral span portion; and The central closing of the span portion is performed after the temporary closing of the first lateral span portion, and the connecting portion of the first lateral span portion and the second lateral span portion of the first lateral span portion. The connecting portion is characterized in that the central closing is performed in order from the center closing portion of the central span portion after the central closing portion and closer to the central span portion.

  According to this configuration, even before the central span portion is centrally closed, the existing portions of the bridge girder are connected by temporary closing and can be used as a construction road.

  The method according to at least some embodiments of the present invention includes, in the above-described configuration, after constructing the overhanging portion (6) projecting from a certain pier (P (i-1)) of the bridge girder and the pier ( P (i-1)) and the connecting portion of the span portion supported by the pier (P (i)) adjacent to the one side of the pier (P (i-1)) or the abutment After the temporary closing or the central closing, the overhanging part is constructed from the pier (P (i-2)) or the abutment adjacent to the other side of the pier (P (i-1)). The bridge girder is constructed by repeating the above.

  According to this configuration, the bridge girder is constructed sequentially from one side in the bridge axis direction, and the entire existing part of the bridge girder can be used as a construction road. In addition, it can be installed with one installation girder.

  A temporary closing structure (10) according to at least some embodiments of the present invention comprises two adjacent piers (1) in a concrete bridge (1) having a rigid frame structure including a box girder constructed using precast concrete segments. 4) or a temporary closing structure of the connecting portion (9) disposed at the center position in the bridge axis direction of the span portion (8) spanned between the abutments (3), the connecting segment (11); Precast concrete segment-made main body portions (12a, 12b, 12c) are arranged on one side in the bridge axis direction of the connecting segment, and enter the internal space (11d) of the connecting segment to support the connecting segment. A first segment (12) having a first protrusion (17), and a main body (13a, 13b, 13c) made of a precast concrete segment; And a second protrusion (19) which is disposed on the other side of the connecting segment in the bridge axis direction and enters the internal space of the connecting segment to support the connecting segment and faces the first protrusion in the bridge axis direction. ) Having a second segment (13), and a horizontal force jack (14) capable of being applied in a bridge axis direction can be disposed between the first protrusion and the second protrusion. And

  By applying this configuration to a bridge girder constructed by a concrete bridge cantilever overhang construction method, the existing part of the bridge girder is temporarily closed and can be used as a construction road. Later, horizontal force is applied and rigid coupling is applied. Central closure can be performed.

  In the method according to at least some embodiments of the present invention, in the above configuration, the lower wall (11b) of the connection segment is notched at a position aligned with the first protrusion and the second protrusion in the vertical direction ( 20), and the upper wall (11a) of the connecting segment is supported by the first and second protrusions via a lock jack (15).

  According to this structure, after arrange | positioning a 1st and 2nd segment in a predetermined position, it can construct so that a connection segment may be dropped from upper direction between both. Further, since the height of the connecting segment can be adjusted to reduce the step between the first and second segments, the traveling performance of the construction vehicle passing over the connecting segment in the temporarily closed state can be improved.

  The method according to at least some embodiments of the present invention is characterized in that, in the above configuration, the upper wall of the connecting segment is provided with an opening (22) through which the jack for horizontal force can pass. To do.

  According to this configuration, the horizontal force jack can be taken out through the opening after the central closing.

  ADVANTAGE OF THE INVENTION According to this invention, when installing the bridge girder of the concrete bridge which has a ramen structure by the cantilever-type overhang construction method, the method which can use the existing part of a bridge girder as a construction road, and the temporary closing structure for it are provided. it can.

Explanatory drawing which shows the construction procedure of the bridge girder of the concrete bridge which concerns on embodiment Explanatory drawing which shows the construction procedure of the bridge girder of the concrete bridge which concerns on embodiment Explanatory drawing which shows the construction procedure of the bridge girder of the concrete bridge which concerns on embodiment Sectional drawing in the surface orthogonal to the bridge axis of the span center of the rigid frame structure part of the concrete bridge which concerns on embodiment (IV-IV cross section in FIG.5 and FIG.6) Sectional drawing of the span center of the ramen structure part of the concrete bridge which concerns on embodiment (VV cross section in FIG.4 and FIG.6) Sectional drawing of the span center of the ramen structure part of the concrete bridge which concerns on embodiment (VI-VI cross section in FIG.4 and FIG.5)

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIGS. 1-3 shows the construction procedure of the bridge girder 2 of the concrete bridge 1 which concerns on embodiment. The concrete bridge 1 has two abutments 3 (A1 and A2) and fourteen piers 4 (P1 to P14). The abutments 3A1 and A2 and the piers 4P1 to P3 and P10 to P14 support the bridge girder 2 via the support 5. The piers 4P4 to P9 are rigidly connected to the bridge girder 2. The bridge girder 2 is continuous, and the bridge piers 4P4 to P9 and the span portion 8 (the portion between the bridge piers 4P3 to P10 in the bridge girder 2) supported at both ends or one end thereof constitute a ramen structure. The span lengths of the piers 4P3 to P10 are equal to each other, but may be different.

  The bridge girder 2 is a box girder constructed by connecting a plurality of precast concrete (hereinafter referred to as “PCa”) segments with a plurality of PC cables (not shown) extending in the bridge axis direction. Note that the bridge girder 2 may be constructed of on-site concrete. The bridge girder 2 is constructed by a cantilever-type overhanging construction method in which overhang portions 6 projecting on both sides of the pier 4 are constructed and the ends of the overhang portions 6 and 6 facing each other are rigidly connected. The overhang | projection part 6 is formed in an order from the overhang | projection from the bridge pier 4 of the side near the abutment 3A2. The overhanging part 6 of the piers 4P11 to P1 erected in the river is a bridge pier 4 that is intended to form the overhanging part 6 on the existing bridge girder 2 by a transport vehicle such as a trailer, and the front and rear of the pier 4 It constructs | assembles by arrange | positioning in a construction position by the construction girder 7 fixed to the pier 4 or the abutment 3 (FIGS. 1-3 (b)-(k)).

  In the bridge girder 2, the span portion 8, which is a portion spanned between two adjacent piers 4 or abutments 3, has a connecting portion 9 that connects the ends of the two overhanging portions 6 that face each other. As shown in FIGS. 1B and 1C, the connecting portion 9 of the span portion 8 supported at both ends by the support 5 is rigidly connected so as to transmit axial force, shearing force and bending moment. When the center is closed, the overhanging portion 6 is constructed on the next pier 4. Specifically, after the central closing is performed at the connecting portion 9 of the span portion 8 between the piers 4P12 and P11 (FIG. 1 (b)), the overhang portions 6 are constructed on both sides of the pier 4P10, and the piers 4P11 and P10 are formed. The connecting portion 9 of the span portion 8 is centrally closed (FIG. 1 (c)). Although the connection aspect of the connection part 9 may differ, also in other parts, after the connection part 9 of the span part 8 between bridge piers 4P (i) and P (i-1) is connected, bridge pier 4P ( The operation of constructing the overhang portions 6 on both sides of i-2) is repeated (i is an integer of 14 to 3).

  The span portion 8 constituting the ramen structure is located on the abutment 3A1 side with respect to the three first lateral span portions 8a (between P10 and P7) and the first lateral span portion 8a. One central span portion 8b (between P7 and P6) located at the center of the center, and three second side span portions 8c (between P6 and P3) located closer to the abutment 3A1 than the central span portion 8b. including.

  As shown in FIG. 1 (d), in the state where the connecting portion 9 of the first side span portion 8a is temporarily closed, the overhang portion of the pier 4 on the abutment 3A1 side from the first side span portion 8a. 6 is built. Specifically, after the connecting portion 9 of the first lateral span portion 8a between the piers 4P (i) and P (i-1) is temporarily closed, the overhang portions are formed on both sides of the pier 4P (i-2). 6 is built (i is 10, 9 or 8). Temporary closing is a temporary connection by pin connection, which means that a shearing force is transmitted but a bending moment is not transmitted, and a horizontal force can be applied later. A central closure by a rigid connection is planned later. Here, “without transmitting the bending moment” means that the amount of transmission of the bending moment is negligible in the design calculation.

  When the overhanging portion 6 of the pier 4P6 is constructed, the connecting portion 9 of the central span portion 8b located between the piers 4P7 and P6 is closed at the center, and the first and second lateral span portions 8a and 8c are connected. It functions as a reaction table when horizontal force is applied to the portion 9.

  As shown in FIG.2 (e), after the connection part 9 of the center span part 8b is center-closed, the overhang | projection part 6 is constructed | assembled on the both sides of the pier 4P5. The connecting portion 9 of the second side span portion 8c between the piers 4P6 and P5 is subjected to horizontal force, and then is centrally closed in that state. Moreover, as shown in FIG.2 (f), after performing horizontal force, the connection part 9 of the 1st side diameter part 8a between the piers 4P8 and P7 is also centrally closed in that state. It should be noted that the horizontal force and central closing of the connecting portion 9 at the second side span portion 8c between the piers 4P6 and P5 and the horizontal addition of the connecting portion 9 at the first side span portion 8a between the piers 4P8 and P7. Since the distance from the connection part 9 of the center span part 8b is equal to each other, either force or center closing may be performed first.

  Thereafter, as shown in FIGS. 2 (g) and (h), after the overhang portions 6 are constructed on both sides of the pier 4P4, the connecting portion 9 and the pier of the second side span portion 8c between the piers 4P5 and P4. The connecting portion 9 of the first side-diameter portion 8a between 4P9 and P8 is subjected to horizontal force, and then is centrally closed in that state.

  Thereafter, as shown in FIG. 3 (i), after the overhang portions 6 are constructed on both sides of the pier 4P3, between the connecting portion 9 and the piers 4P10 and P9 of the second lateral span 8c between the piers 4P4 and P3. The connecting portion 9 of the first side span portion 8a is centrally closed. Since the bridge piers 4P3 and P10 support the bridge girder 2 through the support 5, the connecting portion 9 of the second lateral span 8c between the bridge piers 4P4 and P3 and the first lateral span between the bridge piers 4P10 and P9. No horizontal force is applied at the connecting portion 9 of the portion 8a.

  Further, as shown in FIGS. 3 (j) and 3 (k), the span portion 8 between the pier 4P3 and the abutment 3A1 supported at both ends is supported by the construction of the overhang portion 6 and the central closing of the connecting portion 9. As shown in FIG. 3 (l), the construction of the bridge girder 2 is completed.

  In addition, also in the connection part 9 of the 2nd side diameter part 8c, temporary closure is performed and the overhang | projection part 6 from the pier 4 in the abutment 3A1 side is constructed rather than the 2nd side diameter part 8c. Then, the horizontal force and center closing of the first side span portion 8a and the second side span portion 8c may be performed later. In this case, the central closing is performed in order from the one closest to the central span portion 8b, and one that is equidistant may be performed first.

  Next, with reference to FIGS. 4-6, the temporary closing structure 10 of the connection part 9 is demonstrated. The temporary closing structure 10 includes a connecting segment 11, a first segment 12 and a second segment 13 that cooperate to support the connecting segment 11, a horizontal force jack 14, and a lock for adjusting the height of the connecting segment 11. And a jack 15.

  The connecting segment 11, the first segment 12, and the second segment 13 are respectively connected to the upper walls 11a, 12a, and 13a, the lower walls 11b, 12b, and 13b, the upper ends thereof are connected to the upper walls 11a, 12a, and 13a, and the lower ends thereof. An internal space 11d having a pair of left and right side walls 11c, 11c, 12c, 12c, 13c, and 13c connected to the lower walls 11b, 12b, and 13b, and a surface in the bridge axis direction being opened by these walls; 12d and 13d are defined. The upper walls 11a, 12a, 13a are aligned with each other in the bridge axis direction, the lower walls 11b, 12b, 13b are aligned with each other in the bridge axis direction, and the pair of left and right side walls 11c, 11c, 12c, 12c, 13c, 13c are They are arranged so as to be aligned with each other in the direction of the bridge axis.

  The first segment 12 and the second segment 13 are substantially mirror-symmetric with respect to a plane that passes through an intermediate point between them and is orthogonal to the bridge axis. A pair of first bulges 16, 16 bulged from the upper wall 12 a and the respective side walls 12 c are provided at the left and right upper corners inside the first segment 12. A first protrusion 17 that protrudes along the bridge axis direction is provided from the surface of each first bulging portion 16 on the connection segment 11 side. The first protrusion 17 protrudes into the internal space 11d of the connecting segment 11, and the upper surface thereof is separated from the back surface of the upper wall 11a. Similarly, a pair of second bulging portions 18, 18 bulging from the upper wall 13 a and the respective side walls 13 c are provided at the left and right upper corners inside the second segment 13. A second protrusion 19 that protrudes along the bridge axis direction is provided from the surface of each second bulging portion 18 on the connecting segment 11 side. The second protrusion 19 protrudes into the internal space 11d of the connecting segment 11, and the upper surface thereof is separated from the back surface of the upper wall 11a. The tip of the first protrusion 17 is separated from the tip of the second protrusion 19 in the bridge axis direction. In each of the first segment 12 and the second segment 13, the main body including the upper walls 12a, 13a, the lower walls 12b, 13b, and the pair of left and right side walls 12c, 12c, 13c, 13c is made of PCa. The first and second bulging portions 16 and 18 and the first and second protrusions 17 and 19 may be made of concrete or steel.

  The lower wall 11b of the connecting segment 11 is provided with a notch 20 at a position aligned with each of the first and second protrusions 17, 17, 19, 19 in the vertical direction. Since the first and second protrusions 17, 17, 19, and 19 can pass through the corresponding notches 20, respectively, the first and second segments constituting the tip portion of the overhang portion 6 (see FIGS. 1 and 2). After 12 and 13 are arranged, the connecting segment 11 can be dropped between the first and second segments 12 and 13 from above. The dropped connection segment 11 is supported by the lock jack 15 placed on the upper surfaces of the first and second protrusions 17 and 19 on the back surface of the upper wall 11a. The height of the connecting segment 11 can be adjusted by the lock jack 15 to reduce the level difference between the connecting segment 11 and the first and second segments 12 and 13. Between each of the first and second protrusions 17 and 19 and the side wall 11c on the left and right sides of the first and second protrusions 17 and 19, an anti-blur member 21 that contacts both is disposed, and a connecting segment 11 is restricted from moving in the left-right direction. The anti-blur member 21 is constructed of, for example, cast-in-place concrete, but may be composed of other materials. In the temporarily closed state, the connecting segment 11 is only supported by the lock jack 15 and the anti-blur member 21, and the fixing to the first and second segments 12 and 13 by the PC cable or the like is performed at the center closing time. The connecting segment 11 may be made of PCa or steel, and these may be mixed. For example, the main body including the upper wall 11a, the lower wall 11b, and the pair of left and right side walls 11c, 11c may be made of PCa, and the anti-blur member 21 may be made of steel.

  In each of the left and right sides, the tip surface of the first projection 17 and the tip surface of the second projection 19 face each other, and both cooperate to sandwich the horizontal force jack 14 extending along the bridge axis direction. . The horizontal force jack 14 has a notch shape obtained by cutting a cylinder having an axis in the left-right direction along a plane perpendicular to the bridge axis, or a notch-shaped convex part obtained by cutting a sphere along a plane perpendicular to the bridge axis, Since it has a joint part 14a having a concave part for slidably fitting the part, shear force is transmitted between the first and second segments 12 and 13 when sandwiched between the first and second protrusions 17 and 19. However, the bending moment is not transmitted. Therefore, even if the horizontal force jack 14 is installed, the state where the first and second segments 12 and 13 are pin-coupled to each other is maintained. Horizontal force can be applied by extending or contracting the horizontal force jack 14 in the direction of the bridge axis. Further, the upper wall 11a of the connecting segment 11 is provided with an opening 22 through which the horizontal force jack 14 can pass. Therefore, the horizontal force jack 14 can be taken out through the opening 22 after the central closing. The horizontal force jack 14 may not be installed at the time of temporary closing, but may be installed after the temporary closing and before the horizontal force is applied.

  By temporarily closing the connecting portion 9 of the first side span portion 8a, the connecting portion 9 is connected so as not to transmit a bending moment. Can be prevented from occurring on the pier 4 and the abutment 3. Further, since the bridge girder 2 is constructed sequentially from one direction, the construction vehicle can pass through the existing part of the bridge girder 2 by connection by temporary closing.

  The height of the connecting segment 11 at the time of temporary closing can be adjusted by the lock jack 15 to reduce the level difference between the connecting segment 11 and the first and second segments 12, 13. The running performance of the vehicle can be improved.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. When there are two spans located at the center in the bridge axis direction of the ramen structure part, such as when the span length of the ramen structure part is constant and the span part of the ramen structure part is even, Two spans may be provided. The bridge girder may be constructed from both ends of the bridge girder toward the center.

1: concrete bridge 2: bridge girder 3: abutment 4: pier 5: support 6: overhang 7: erection girder 8: span (8a: first lateral span, 8b: central span, 8c: first 2 side span part)
9: Connection part 10: Temporary closing structure 11: Connection segment 12: 1st segment 13: 2nd segment 14: Jack for horizontal force (14a: Joint part)
15: Lock jack 16: First bulge
17: 1st protrusion 18: 2nd bulging part
19: 2nd protrusion 20: Notch 21: Anti-blur material 22: Opening

Claims (5)

In the ramen structure, comprising two or more adjacent piers in a bridge girder or a ramen structure formed by rigidly connecting three or more continuous spans spanned between abutments to the pier. Each of the span portions has a connecting portion at a central position in the respective bridge axis direction, and the span portion in the ramen structure is one or two central span portions located in the center of the ramen structure; One or more first lateral spans located on one side of the central span in the bridge axis direction and one or more second laterals located on the other span span in the central span A method of installing the bridge girder of a concrete bridge including a span portion by a cantilever-type overhang construction method,
Constructing the first lateral span part, including connecting the coupling part of the first lateral span part by temporary closing that is a pin connection and can apply horizontal force later;
Constructing the central span portion, including coupling the coupling portion of the central span portion by a central closure by rigid coupling;
Building the second lateral span,
The central closing of the central span portion is performed after the temporary closure of the first lateral span portion,
The connecting portion of the first lateral span portion and the connecting portion of the second lateral span portion are after the central closing of the central span portion and close to the central span portion. The method is characterized in that the central closure is performed in order.   The connecting portion of the span portion supported by the bridge pier or the abutment adjacent to the bridge pier and the one side of the bridge pier after the overhanging portion extending from the pier in the bridge girder is constructed. The bridge girder is constructed by repeatedly constructing the projecting portion from the abutment or the abutment adjacent to the other side of the pier after the temporary closure or the center closure. Item 2. The method according to Item 1. In a concrete bridge with a rigid frame structure including a box girder constructed using precast concrete segments, the connection is arranged at the center position in the bridge axis direction of the span spanned between two adjacent piers or abutments Part temporary closure structure,
A consolidated segment;
A main body made of precast concrete, and a first segment that is disposed on one side of the connecting segment in the bridge axis direction and has a first protrusion that projects into an internal space of the connecting segment to support the connecting segment;
A main body made of precast concrete, and disposed on the other side of the connecting segment in the bridge axis direction, enters the inner space of the connecting segment to support the connecting segment and extends in the bridge axis direction to the first protrusion. A second segment having opposing second protrusions,
A temporary closing structure characterized in that a horizontal force jack capable of applying force in the bridge axis direction can be disposed between the first protrusion and the second protrusion. The lower wall of the connecting segment is provided with a notch at a position aligned with the first protrusion and the second protrusion in the vertical direction,
4. The temporary closing structure according to claim 3, wherein an upper wall of the connection segment is supported by the first protrusion and the second protrusion via a lock jack. 5.   The temporary closing structure according to claim 3 or 4, wherein an opening through which the horizontal force jack can pass is provided in an upper wall of the connection segment.

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