Cable-stayed bridge erection method, lifting equipment and cable-stayed bridge

Abstract

To reduce a work period in erection work of a cable-stayed bridge as compared to the conventional one.SOLUTION: An erection method of a cable-stayed bridge comprises: a main girder supporting step of giving a force with upward components in a vertical direction to main girders 106 and supporting the main girders by first cables 104 receiving an upward force from a main tower 102; a lifting machine arrangement step of arranging lifting machines 20 onto predetermined positions of the main girders 106; a tensile force introducing step of introducing a tensile force to second cables 30 connecting between tip side parts of the lifting machines 20 arranged to the predetermined positions and the main tower 102 so that the force with the upward components in a vertical direction is applied to the lifting machines 20; a lifting step of lifting main girder blocks 80 up to a predetermined height by using the lifting machines 20 after the tensile force introducing step; and a main girder blocks supporting step of giving the force with upward components in a vertical direction to the main girder blocks 80 and supporting the main girder blocks by third cables 104 receiving the upward force from the main tower 102 while joining the main girder blocks 80 to tip sides of the main girders 106.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cable-stayed bridge erection method, a lifting machine, and a cable-stayed bridge, and more particularly to a cable-stayed bridge erection method, a lifting machine, and a cable-stayed bridge that can shorten the construction period compared to conventional methods. Note that in this application, the term "cable-stayed bridge" also includes extradosed bridges. [Background technology]

[0002] In the erection of the main girders of a cable-stayed bridge, the work has traditionally been carried out by using a balancing erection method, whereby erection and cable anchoring are carried out block by block on each side (see, for example, Non-Patent Document 1).

[0003] When constructing a cable-stayed bridge over water using the balancing erection method, the main girder block is transported below the erection site on a barge or other means, lifted by a lifting device installed on the already erected main girder, joined to the tip of the already erected main girder, and the cable is fixed to the main girder block and tension is applied to the cable to complete the erection. Because these processes must be carried out for each main girder block as the bridge is erected, it is difficult to shorten the construction period, and navigation restrictions in the water area will be required for a long period of time during the erection of the main girders. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] "Balancing cantilever construction method," Japan Bridge Construction Association, [online], [Retrieved April 11, 2022], Internet<URL:https: / / www.jasbc.or.jp / flowchart / 07.php> Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the above points, and an object of the present invention is to provide a cable-stayed bridge erection method, a lifting machine, and a cable-stayed bridge that can shorten the construction period for cable-stayed bridge erection work compared to conventional methods. [Means for solving the problem]

[0006] The present invention is an invention that solves the above-mentioned problems, and provides a cable-stayed bridge erection method, a lifting machine, and a cable-stayed bridge as described below.

[0007] That is, a first aspect of the cable-stayed bridge erection method according to the present invention is a method for erecting a cable-stayed bridge having a main tower and a main girder, comprising: a main girder supporting step of supporting the main girder by applying a force having a vertically upward component to the main girder with a first cable that receives a force having a vertically upward component from the main tower; a lifting machine arranging step of arranging a lifting machine at a predetermined position on the main girder; a tensioning step of introducing tension into a second cable that connects the tip end portion of the lifting machine arranged at the predetermined position to the main tower so that the force having a vertically upward component is applied to the lifting machine; and This method for erecting a cable-stayed bridge comprises: a lifting process in which the main girder block to be erected at the tip of the girder away from the main tower is lifted to a predetermined height using the crane; and a main girder block support process in which the main girder block lifted to the predetermined height in the lifting process is joined to the tip of the main girder, and a third cable that receives a force having a vertically upward component from the main tower applies a force having a vertically upward component to the main girder block lifted to the predetermined height in the lifting process, thereby supporting the main girder block as part of a new main girder.

[0008] Here, the phrase "the first cable is subjected to a force having a vertically upward component from the main tower" includes not only the case where the first cable is anchored to the main tower of the cable-stayed bridge and the first cable is subjected to a force having a vertically upward component from its anchorage to the main tower, but also the case where a through-saddle section through which the first cable passes is formed in the main tower, the first cable passing through the through-saddle section is tensioned and anchored at the anchorage sections of the main girder blocks arranged on the left and right sides of the main tower, and the first cable is subjected to a force having a vertically upward component from the main tower. The same applies to the third cable, and similar descriptions elsewhere in this application shall be interpreted in the same way.

[0009] Furthermore, the statement that the second cable "connects the tip end portion of the lifting machine placed at the specified position to the main tower" does not only mean that one end of the second cable is fixed to the main tower and connected thereto, but also that one end of the second cable is fixed to an already installed main girder or the ground, etc., and the middle portion of the second cable is subjected to a force having a vertically upward component from the main tower or a member attached to the main tower.

[0010] A second aspect of the cable-stayed bridge erection method of the present invention is the first aspect of the cable-stayed bridge erection method, characterized in that the position of the tip end portion of the lifting machine to which the second cable is connected is farther from the main tower than the portion of the main girder to which the vertical downward load of the lifting machine is applied.

[0011] A third aspect of the cable-stayed bridge erection method of the present invention is the first or second aspect of the cable-stayed bridge erection method, characterized in that in the tension introduction step, the direction of extension of the second cable is changed between the anchorage point at the tip end of the lifting machine and the anchorage point at a point other than the lifting machine in a direction different from the direction of extension of a straight line connecting the anchorage point at the tip end of the lifting machine and the anchorage point at a point other than the lifting machine, and the tension is introduced.

[0012] Here, examples of "anchoring parts other than the lifting machine" of the second cable include parts of the main tower and the main girder, as well as parts of ground structures other than the cable-stayed bridge.

[0013] A fourth aspect of the cable-stayed bridge erection method of the present invention is the third aspect of the cable-stayed bridge erection method, characterized in that the change in the extension direction of the second cable in the tension introduction process is performed by an angle-changing member provided on the main tower.

[0014] A fifth aspect of the cable-stayed bridge erection method according to the present invention is the third aspect of the cable-stayed bridge erection method, characterized in that the change in the extension direction of the second cable in the tension introduction process is performed by an angle change member provided on the lifting machine.

[0015] A sixth aspect of the cable-stayed bridge erection method according to the present invention is the third aspect of the cable-stayed bridge erection method, characterized in that the change in the extension direction of the second cable in the tension introduction process is performed by an angle change member provided on the main tower and also by an angle change member provided on the lifting machine.

[0016] A seventh aspect of the cable-stayed bridge erection method of the present invention is the sixth aspect of the cable-stayed bridge erection method, characterized in that the lifting machine-side tension introduction section that introduces tension into the second cable and the anchoring section of the second cable to the tip end section of the lifting machine are located closer to the lifting machine-side end of the second cable than the section of the second cable that contacts the angle-changing member provided on the lifting machine, and the lifting process is carried out after the lifting machine-side tension introduction section makes a final adjustment of the tension of the second cable in the tension introduction process.

[0017] Here, "the fixing portion of the second cable to the tip end portion of the lifting machine" includes not only the portion where the second cable is directly fixed to the tip end portion of the lifting machine, but also the portion where the second cable is indirectly fixed to the tip end portion of the lifting machine via another member. Similar descriptions elsewhere in this application shall be interpreted in the same manner.

[0018] An eighth aspect of the cable-stayed bridge erection method according to the present invention is any one of the fourth, sixth and seventh aspects of the cable-stayed bridge erection method, characterized in that in the tension introduction step, the direction of extension of the second cable is changed by the angle change member provided on the main tower of the cable-stayed bridge, and the second cable is fixed at a position below the angle change member and tension is introduced thereto.

[0019] A ninth aspect of the cable-stayed bridge erection method according to the present invention is any one of the first to seventh aspects of the cable-stayed bridge erection method, further comprising: a tension releasing step of releasing the tension on the second cable after the main girder block supporting step; a cable separating step of separating the second cable midway after the tension releasing step; a lifting machine relocating step of relocating the lifting machine to a predetermined position on the new main girder formed by joining and supporting the main girder block in the main girder block supporting step after the cable separating step; a cable joining step of joining a cable to the second cable separated midway in the cable separating step to make an extended second cable with an increased overall length; This aspect is characterized by comprising: a tension reintroduction process for introducing tension into the second cable after the extension; a second lifting process for lifting the main girder block to be erected as a main girder member of the cable-stayed bridge to a predetermined height using the lifting machine repositioned in the lifting machine repositioning process after the tension reintroduction process; and a second main girder block support process for joining the main girder block lifted to the predetermined height in the second lifting process to the new main girder, and applying a force having a vertically upward component to the main girder block lifted to the predetermined height in the second lifting process using a fourth cable that receives a force having a vertically upward component from the main tower, thereby supporting the main girder block as part of the new main girder.

[0020] A tenth aspect of the cable-stayed bridge erection method according to the present invention is the eighth aspect of the cable-stayed bridge erection method, further comprising: a tension releasing step of releasing the tension on the second cable after the main girder block supporting step; a cable separating step of separating the second cable midway after the tension releasing step; a crane relocating step of relocating the crane to a predetermined position on the new main girder formed by joining and supporting the main girder block in the main girder block supporting step after the cable separating step; a cable joining step of joining a cable to the second cable separated midway in the cable separating step to form an extended second cable with an increased overall length; a tension reintroduction step of introducing tension into the extended second cable with an increased overall length in the cable joining step; and a cable reintroduction step of erecting the second cable as a main girder member of the cable-stayed bridge after the tension reintroduction step. and a second main girder block support process in which the main girder block to be lifted in the second lifting process is lifted to a predetermined height using the lifting machine repositioned in the lifting machine repositioning process, and the main girder block lifted to the predetermined height in the second lifting process is joined to the new main girder, and a fourth cable that receives a force having a vertically upward component from the main tower applies a force having a vertically upward component to the main girder block lifted to the predetermined height in the second lifting process, thereby supporting the main girder block as part of the new main girder, wherein the direction of extension of the extended second cable to which tension has been introduced in the tension reintroduction process is changed by the angle change member provided on the main tower, and the second cable is fixed at a position below the angle change member and tension is introduced thereto.

[0021] A first aspect of the lifting machine of the present invention is a lifting machine used to erect the main girders of a cable-stayed bridge having a main tower, capable of moving on the main girders, characterized in that it comprises: a lifting section that lifts the main girder block to be erected as a main girder member of the cable-stayed bridge from below at a predetermined position on the tip side of the main girder; and a cable connection section at the tip side of the lifting machine that can secure a cable that can receive a force having a vertically upward component from the main tower and apply a force having a vertically upward component to the lifting machine.

[0022] A second aspect of the lifting machine of the present invention is the first aspect of the lifting machine, characterized in that it has an angle change member that changes the extension direction of the cable to a direction different from the extension direction of the straight line connecting the cable connection portion and the portion of the cable that receives a force having a vertically upward component from the main tower.

[0023] A first aspect of the cable-stayed bridge of the present invention is a cable-stayed bridge having a main tower, characterized in that the main tower is equipped with: a first connector, one end of which is fixed to a predetermined position on the main girder of the cable-stayed bridge and is capable of applying a force having a vertically upward component to a first cable that applies a force having a vertically upward component to the main girder; and a second connector, which is arranged at a predetermined position on the main girder and is fixed to a lifting machine that lifts upward a main girder member that is newly installed further forward than the main girder, and is capable of applying a force having a vertically upward component to a second cable that applies a force having a vertically upward component to the lifting machine.

[0024] A second aspect of the cable-stayed bridge of the present invention is the cable-stayed bridge of the first aspect, characterized in that the main tower is provided with an angle-changing member that changes the direction in which the second cable extends to a direction different from the direction in which a straight line connecting the point at which the second cable is attached to the lifting machine and the point at which the second cable is attached to a point other than the lifting machine extends.

[0025] A third aspect of the cable-stayed bridge of the present invention is the cable-stayed bridge of the second aspect, characterized in that the main tower is provided with a bracket at a position lower than the position where the angle-changing member is arranged, and the second cable, whose direction of extension has been changed by the angle-changing member, can be fixed to the bracket.

[0026] A fourth aspect of the cable-stayed bridge of the present invention is the cable-stayed bridge of the second aspect, characterized in that the main tower is provided with an upper bracket and a lower bracket spaced apart vertically at a position lower than the position of the angle-changing member, the lower bracket is provided with a winch that pulls in the second cable, and the upper bracket is provided with a jack that introduces tension vertically into the second cable and an anchoring part that anchors the second cable. [Effects of the Invention]

[0027] According to the present invention, it is possible to provide a cable-stayed bridge erection method, a lifting machine, and a cable-stayed bridge that can shorten the construction period for cable-stayed bridge erection work compared to conventional methods. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a side view of a state in which a main girder block 80 is being erected using a cable-stayed bridge erection device 10 according to an embodiment of the present invention, viewed from a direction perpendicular to the bridge axis. [Figure 2] Plan view of the state in Figure 1 seen from above [Figure 3] 2 is a side view of a portion of the cable-stayed bridge erection device 10 according to the embodiment of the present invention, in the state of FIG. 1, that is close to the main tower 102 of the cable-stayed bridge 100, viewed from a direction perpendicular to the bridge axis. [Figure 4] 2 is a front view of a portion of the cable-stayed bridge erection device 10 according to the embodiment of the present invention, in the state of FIG. 1, that is close to the main tower 102 of the cable-stayed bridge 100, as seen from the bridge axis direction. [Figure 5] 1 is a side view of the crane 20 and its surrounding area, among the components of the cable-stayed bridge erection device 10 according to an embodiment of the present invention, when the main girder block 80 is lifted, viewed from a direction perpendicular to the bridge axis. [Figure 6] Plan view of the state in Figure 5 from above [Figure 7]1 is a side view of the crane 20 and its surrounding area, taken from a direction perpendicular to the bridge axis, of the cable-stayed bridge erection device 10 according to an embodiment of the present invention, in a state in which the temporary cable 30 has been separated midway after the lifted main girder block 80 has been connected to the cable-stayed bridge 100 (after joining to the installed main girder 106 and connection to the main tower 102 by the permanent cable 104 have been completed). [Figure 8] Plan view of the state in Figure 7 from above [Figure 9] 1 is an enlarged side view of the lifting machine 20. [Figure 10] FIG. 10 is an enlarged side view of the fixing portion 20E and its surrounding area. [Figure 11] FIG. 2 is an enlarged plan view of the fixing portion 20E and its surrounding area, as viewed from above. [Figure 12] An enlarged front view of the main tower side anchorage 40, seen from the bridge axis direction. [Figure 13] An enlarged side view of the main tower side anchorage 40, seen from a direction perpendicular to the bridge axis. [Figure 14] 1 is a side view of a portion of a cable-stayed bridge erection device 10 according to an embodiment of the present invention, in a relaxed state before tension is introduced into the temporary cable 30, the portion being close to a main tower 102 of a cable-stayed bridge 100, as viewed from a direction perpendicular to the bridge axis. [Figure 15] 1 is a front view of a portion of a cable-stayed bridge erection device 10 according to an embodiment of the present invention, in a relaxed state before tension is introduced into the temporary cable 30, the portion being close to a main tower 102 of a cable-stayed bridge 100, as seen from the bridge axis direction. [Figure 16] 1 is a side view of a portion of a cable-stayed bridge erection device 10 according to an embodiment of the present invention, the portion being close to a main tower 102 of a cable-stayed bridge 100, viewed from a direction perpendicular to the bridge axis, during the middle stage of introducing tension into the temporary cable 30. [Figure 17] 1 is a front view of a portion of a cable-stayed bridge erection device 10 according to an embodiment of the present invention, the portion being close to a main tower 102 of a cable-stayed bridge 100, viewed from the bridge axis direction, during the middle stage of introducing tension into the temporary cable 30. [Figure 18] 1 is a side view showing a state in which the erection of several main girder blocks 80 has been completed and the erected main girder 106 has been erected during the construction of the cable-stayed bridge 100. [Figure 19] FIG. 1 is a side view schematically showing one step (step S1) of the procedure for erecting a main girder block 80 using a cable-stayed bridge erection device 10 according to an embodiment of the present invention. [Figure 20] FIG. 10 is a side view schematically showing one step (step S2) of the procedure for erecting the main girder block 80 using the cable-stayed bridge erection device 10 according to the embodiment of the present invention. [Figure 21] FIG. 10 is a side view schematically showing one step (step S3) of the procedure for erecting the main girder block 80 using the cable-stayed bridge erection device 10 according to the embodiment of the present invention. [Figure 22] FIG. 10 is a side view schematically showing one step (step S4) of the procedure for erecting the main girder block 80 using the cable-stayed bridge erection device 10 according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the description of the embodiments of the present invention, it is assumed that the main girder blocks of a cable-stayed bridge are made of steel. However, the main girder blocks of cable-stayed bridges to which the present invention is applicable are not limited to those made of steel, and the present invention can also be applied to cases where the main girder blocks are made of concrete. The present invention can also be applied to extradosed bridges.

[0030] (1) Embodiment of cable-stayed bridge erection device FIG. 1 is a side view of a state in which a main girder block 80 is being erected using a cable-stayed bridge erection device 10 according to an embodiment of the present invention, as seen from a direction perpendicular to the bridge axis; FIG. 2 is a plan view of the state of FIG. 1, as seen from above; FIG. 3 is a side view of a portion of the cable-stayed bridge erection device 10 according to an embodiment of the present invention in the state of FIG. 1, which is close to the main tower 102 of the cable-stayed bridge 100, as seen from a direction perpendicular to the bridge axis; FIG. 4 is a front view of a portion of the cable-stayed bridge erection device 10 according to an embodiment of the present invention in the state of FIG. 1, which is close to the main tower 102 of the cable-stayed bridge 100, as seen from the bridge axis direction; and FIG. 5 is a side view of the cable-stayed bridge erection device 10 according to an embodiment of the present invention, as seen from a direction perpendicular to the bridge axis, with the main girder block 80 being lifted. Fig. 6 is a side view of the cable-stayed bridge erection device 10, showing the lifting machine 20 and its surrounding area, as viewed from a direction perpendicular to the bridge axis. Fig. 6 is a plan view of the state shown in Fig. 5, seen from above. Fig. 7 is a side view of the cable-stayed bridge erection device 10 according to an embodiment of the present invention, showing the lifting machine 20 and its surrounding area, as viewed from a direction perpendicular to the bridge axis, in a state in which the temporary cable 30 has been separated midway after the lifted main girder block 80 has been connected to the cable-stayed bridge 100 (after joining to the installed main girder 106 and connection to the main tower 102 by the permanent cable 104 have been completed). Fig. 8 is a plan view of the state shown in Fig. 7, seen from above. Fig. 9 is an enlarged side view of the lifting machine 20. In Figs. 1 to 4, the temporary cable 30 connected to the lifting machine 20 on the left side in Fig. 1 is indicated by a solid line, and the temporary cable 30 connected to the lifting machine 20 on the right side in Fig. 1 is indicated by a dashed line. In Fig. 1, reference numeral 110 denotes a pier, and reference numeral 112 denotes a diagonal bent. In Fig. 2, the main girder block 80, which is currently being erected while suspended by the crane 20, is hatched with diagonal lines. For convenience of illustration, the permanent cables 104 and wires 20D are not depicted in Figs. 2, 6, and 8. Note that although the cable-stayed bridge 100 is currently being erected in the state shown in Figs. 1 to 8, the term "cable-stayed bridge" in this application also includes a cable-stayed bridge currently being erected.

[0031] A cable-stayed bridge erection device 10 according to an embodiment of the present invention (hereinafter sometimes simply referred to as the "erection device 10") is a device that connects and erects a main girder block 80 to a cable-stayed bridge 100. The device comprises a crane 20, a temporary cable 30, a main tower top deflector 32, and a main tower-side anchorage 40. The device erects the main girder block 80 by pulling the tip of the crane 20 (the side opposite the main tower 102) upward with the temporary cable 30 using a force that has a vertically upward component. This allows for the erection of heavier main girder blocks than those erected using conventional balancing erection methods. The main girder block 80 erected by the erection device 10 according to this embodiment is constructed by previously connecting two main girder blocks longitudinally, each of which is equivalent in size to a main girder block erected using conventional balancing erection methods.

[0032] The lifting machine 20 is a device that lifts the main girder block 80 to be installed at a position farther from the main tower 102 than the tip 106A of the installed main girder 106, and is positioned on the area on the tip side of the installed main girder 106 (the opposite side from the main tower 102), as shown in Figure 1.

[0033] The lifting machine 20 comprises a main body 20A, a suspending unit 20B, a winch 20C, a wire 20D, an anchoring unit 20E, a deflector 20F, and a fixed facility 20G. The temporary cable 30 is anchored to the anchoring unit 20E with the deflector 20F slightly increasing the angle of the direction toward the anchoring unit 20E relative to the horizontal plane. The temporary cable 30 pulls the portion near the tip of the main body 20A (the portion near the suspending unit 20B) upward with a force having a vertically upward component. For this reason, the weight that the lifting machine 20 can lift is greater than the weight that a lifting machine in a conventional balancing erection method can lift. As described above, the main girder block 80 erected by the erection device 10 according to this embodiment is constructed by connecting two main girder blocks, each of a size equivalent to that of a main girder block erected by a conventional balancing erection method, longitudinally in advance.

[0034] As shown in Figure 5, the lifting machine 20 is positioned so that the tip end portion of the main body 20A protrudes in a direction away from the main tower 102 beyond the tip 106A of the installed main girder 106 (the tip end portion of the main body 20A, which protrudes in a direction away from the main tower 102 beyond the tip 106A of the installed main girder 106 when the main girder block 80 to be installed is lifted, will be referred to as the tip end portion 20A3 below). The tip end portion 20A3 of the main body 20A is provided with a suspension portion 20B and an anchoring portion 20E. Therefore, the position of the anchoring portion 20E is farther from the main tower 102 than the portion of the installed main girder 106 to which the vertically downward load of the lifting machine 20 is applied.

[0035] Furthermore, a winch 20C that retracts and pulls out the wire 20D is provided at a location of the main body 20A closer to the main tower 102. As shown in Figure 9, the suspending section 20B is equipped with fixed pulleys 20B1, 20B2 and a movable pulley 20B3, and is configured so that the movable pulley 20B3 rises or falls as the winch 20C retracts or pulls out the wire 20D, thereby enabling the main girder block 80 to be raised or lowered.

[0036] As shown in Fig. 6, the main body 20A includes two parallel-arranged long beam members 20A1 and a cross beam 20A2 connecting the two long beam members 20A1. As shown in Fig. 5, the cross beam 20A2 is located at a distal end portion 20A3 of the main body 20A. As shown in Figs. 10 and 11, the cross beam 20A2 is provided with an anchoring portion 20E and a deflector 20F. Fig. 10 is an enlarged side view of the anchoring portion 20E and its surrounding area, and Fig. 11 is an enlarged plan view of the anchoring portion 20E and its surrounding area viewed from above.

[0037] 10 and 11, the anchoring portion 20E is fixed to the cross beam 20A2, and the tension of the temporary cable 30 is transmitted to the cross beam 20A2 via the anchoring portion 20E, and the upward pulling force is transmitted to the main body portion 20A. As shown in Fig. 10, the temporary cable 30 is changed by a deflector 20F provided on the cross beam 20A2 just before being anchored to the anchoring portion 20E so that the angle it forms with the horizontal plane becomes larger, and the tension of the temporary cable 30 is effectively applied to the lifting machine 20 as an upward force, and the lifting machine 20 can be effectively pulled upward.

[0038] Furthermore, the angle of the temporary cable 30 extending from the main tower top deflector 32 toward the crane 20 with respect to the horizontal plane changes depending on the distance from the main tower 102 to the point where the main girder block 80 is pulled up, but by providing the deflector 20F, the angle of the temporary cable 30 with respect to the horizontal plane can be always maintained at a constant angle when fixed to the fixing part 20E, regardless of the distance from the main tower 102 to the point where the main girder block 80 is pulled up. Therefore, even if the distance from the main tower 102 to the point where the main girder block 80 is pulled up changes, it is not necessary to adjust the angle of the fixing parts (center hole jack 20E1, ram chair 20E2) of the fixing part 20E with respect to the horizontal plane according to the fixing angle of the temporary cable 30.

[0039] In addition, the lifting machine 20 is provided with a fixed facility 20G below the main body 20A, allowing it to be fixed to the installed main girder 106, and is also provided with a moving device (not shown) below the main body 20A, allowing it to move in accordance with the progress of the installation of the main girder block 80.

[0040] As shown in Figure 1, one end of the temporary cable 30 is fixed to the anchor point 20E of the lifting machine 20, and the other end is fixed to the main tower side anchor point 40 provided on the main tower 102, and has the role of applying a force having a vertically upward component to the lifting machine 20 that lifts the main girder block 80, allowing the lifting machine 20 to lift the main girder block 80, which is heavier than conventional main girder blocks.

[0041] The temporary cable 30 can be disconnected midway and an extension temporary cable 30A (see FIG. 5 ) can be added. When erecting the main girder blocks 80 on the cable-stayed bridge 100 using the erection device 10 according to this embodiment, as the erection of the main girder blocks 80 progresses, the erection position of the main girder blocks 80 moves away from the main tower 102, increasing the length required for the temporary cable 30. However, the length of the temporary cable 30 can be increased by adding the extension temporary cable 30A. The configuration of the connection section that allows the temporary cable 30 to be disconnected midway and the configuration of the connection section required to add the extension temporary cable 30A to the temporary cable 30 can be configured in a manner commonly used to connect cables. Furthermore, the temporary cable 30 can be any cable that has the necessary mechanical properties, durability, etc., without particular limitations. Furthermore, the temporary cable 30 can also be a cable that has the same mechanical properties, durability, etc. as the permanent cable 104.

[0042] The direction of extension of the temporary cable 30 is significantly changed midway by the main tower top deflector 32, and the direction of extension of the temporary cable 30 extending from the side of the crane 20 is changed to a vertically downward direction by the main tower top deflector 32, and the temporary cable 30 is fixed to the main tower side fixing part 40 provided on the main tower 102 of the cable-stayed bridge 100 with its extending direction in the vertically downward direction.

[0043] The pylon top deflector 32 is a semicircular member as shown in Figure 3, and is attached to the side of the top of the pylon 102 as shown in Figures 3 and 4. As shown in Figure 3, the diameter of the semicircle of the pylon top deflector 32 is larger than the width of the pylon 102 in the direction perpendicular to the bridge axis.

[0044] Figure 12 is an enlarged front view of the main tower side anchoring section 40, seen from the bridge axis direction, and Figure 13 is an enlarged side view of the main tower side anchoring section 40, seen from a direction perpendicular to the bridge axis. As shown in Figures 12 and 13, the main tower side anchoring section 40 is composed of a lower bracket 42, a reinforcing member 42A for the lower bracket 42, a winch 44, an upper bracket 46, a reinforcing member 46A for the upper bracket 46, a center hole jack 48, and a ram chair 50.

[0045] The lower bracket 42 and the upper bracket 46 are rectangular tubular steel members that are spaced apart vertically (specifically, for example, about 5 m), and are attached to the surface of the main tower 102 facing the bridge axis direction. Reinforcement members 46A and 46B are arranged on the upper bracket 46, to which the temporary cable 30 is fixed, so that the force from the temporary cable 30 can be transmitted to the upper bracket 46, and reinforcing members 42A and 42B are arranged on the lower bracket 42, to which the winch 44 is fixed, so that the force from the winch 44 can be transmitted to the lower bracket 42. The reinforcing members 46A and 46B of the upper bracket 46, to which the temporary cable 30 is fixed, may be arranged so that they form a well shape relative to the upper bracket 46 when viewed from above. The reinforcing members 42A and 42B of the lower bracket 42, to which the winch 44 is fixed, may be arranged so that they form a well shape relative to the lower bracket 42 when viewed from above. A center hole jack 48 and a ram chair 50 for introducing tension into the temporary cable 30 are arranged on the upper bracket 46 to which the temporary cable 30 is fixed.

[0046] Furthermore, through holes through which temporary cable 30 is inserted are provided on the upper and lower surfaces of lower bracket 42 and upper bracket 46, and temporary cable 30 is inserted vertically through lower bracket 42 and upper bracket 46. Furthermore, near the location where temporary cable 30 is inserted, lower bracket 42 is provided with reinforcing member 42B, and upper bracket 46 is provided with reinforcing member 46B, as shown in Figures 12 and 13 .

[0047] Steps a to d for applying tension to the temporary cable 30 and applying a force having a vertically upward component to the crane 20 to pull it upward are described below with reference to Figures 14 to 17, 3, and 4. Figure 14 (side view) and Figure 15 (front view) show the temporary cable 30 in a relaxed state before tension is applied to it, Figure 16 (side view) and Figure 17 (front view) show the temporary cable 30 during the process of applying tension to it, and Figure 3 (side view) and Figure 4 (front view) show the temporary cable 30 after the necessary tension has been applied to it. As shown in Figures 14 to 17, the temporary cable 30 is provided with a tension rod 30B and a cable socket 30C, which are used when applying tension, at a predetermined length from the end of the cable on the main tower 102 side. The cable socket 30C is provided at the rear end of the tension rod 30B (the end on the main tower top deflector 32 side) and connects the temporary cable 30 to the tension rod 30B.

[0048] The steps a to d for applying tension to the temporary cable 30 and applying a force having a vertically upward component to the crane 20 are as follows.

[0049] (a) In the relaxed state before tension is introduced into the temporary cable 30 (the state shown in Figures 13 and 14), the temporary cable 30 is pulled in by the winch 44 of the main tower side anchorage section 40 until the lower part of the tension rod 30B of the temporary cable 30 reaches the center hole jack 48 provided on the upper bracket 46.

[0050] (b) Next, the center hole jack 48 of the main tower anchorage 40 is used repeatedly to pull the tension rod 30B downward until the cable socket 30C provided at the rear end of the tension rod 30B is fully inserted into the ram chair 50. Figures 15 and 16 show intermediate stages of this operation. The length of the tension rod 30B is set so that the lower end of the tension rod 30B reaches the lower bracket 42 when the cable socket 30C is fully inserted into the ram chair 50.

[0051] (c) Once the cable socket 30C provided at the rear end of the tension rod 30B is fully inserted into the ram chair 50, the cable socket 30C inside the ram chair 50 is fixed to the upper bracket 46, and the temporary cable 30 is fixed in place.

[0052] (d) The above-mentioned operations (a) to (c) were performed only at the main tower side anchorage 40, but at the stage when the above-mentioned operations (a) to (c) were completed, a certain degree of tension was introduced into the temporary cable 30. However, after the above-mentioned operations (a) to (c) were completed, the temporary cable 30 was further pulled in by the center hole jack 20E1 of the anchorage 20E of the crane 20 to make a final adjustment to the tension of the temporary cable 30, so that the tension of the temporary cable 30 was set to a tension suitable for lifting the main girder block 80. The part where the tension of the temporary cable 30 directly applies a force having a vertically upward component to the lifting machine 20 is the anchorage 20E of the lifting machine 20. However, between the anchorage 20E of the lifting machine 20 and the main tower-side anchorage 40 of the tensioned temporary cable 30, the main tower top deflector 32 and the deflector 20F of the lifting machine 20 are present. Contact between the main tower top deflector 32 and the deflector 20F of the lifting machine 20 subjects the temporary cable 30 to friction. Therefore, even if the tension of the temporary cable 30 is adjusted at the main tower-side anchorage 40, the adjusted tension of the temporary cable 30 does not act on the anchorage 20E of the lifting machine 20; instead, a tension reduced by the effect of the frictional force acts on the anchorage 20E of the lifting machine 20. For this reason, it is preferable to perform the final adjustment of the tension of the temporary cable 30 at the anchorage 20E of the lifting machine 20. 3 and 4 show the state in which the necessary tension has been applied to the temporary cable 30.

[0053] (2) Embodiment of cable-stayed bridge construction method The cable-stayed bridge erection method according to an embodiment of the present invention is an erection method performed using the cable-stayed bridge erection device 10 described above. The cable-stayed bridge erection method according to an embodiment of the present invention will be described below with reference to Figures 18 to 22. Here, the case of erecting the main girder block 80 in the construction of the cable-stayed bridge 100 will be described.

[0054] Figure 18 is a side view showing the state in which the erection of several main girder blocks 80 has been completed and an already-installed main girder 106 has been installed during the construction of a cable-stayed bridge 100. In Figure 18, the last main girder block 80 to be erected (the main girder block 80 farthest from the main tower 102) is joined to the already-installed main girder 106 and connected to the main tower 102 by a permanent cable 104, thereby becoming a new part of the already-installed main girder 106. A case will be described in which the next main girder block 80 is erected in the state of Figure 18 in which an already-installed main girder 106 has been installed.

[0055] (Step S1) After the erection of the previous main girder block 80 is completed (after joining to the already-installed main girder 106 and connection to the main tower 102 by the permanent cable 104 are completed), the tension on the temporary cable 30 is released. When releasing the tension on the temporary cable 30, the load due to the tension on the temporary cable 30 is transferred to the center hole jack 48 of the main tower side anchorage 40 at the main tower side anchorage 40, and then the cable socket 30C in the ram chair 50 is released from its fixation to the lower bracket 42. Then, the center hole jack 48 is released to completely release the tension on the temporary cable 30. After the tension on the temporary cable 30 is completely released, as shown in Figure 19, the temporary cable 30 is detached midway, and the lifting machine 20 is moved by the fixed equipment 20G to the tip side of the already-installed main girder 106 (the side away from the main tower 102), which is the next erection point. The lifting machine 20 is moved to the area at the tip of the already-installed main girder 106 (the side farthest from the main tower 102), which is the next installation point, and an extension temporary cable 30A is added to the temporary cable 30 that was cut off midway, thereby increasing the length of the temporary cable 30.

[0056] (Step S2) Tension is introduced into the temporary cable 30 to which the extension temporary cable 30A has been joined, and as shown in Fig. 20, a force having an upward vertical component is applied to the lifting machine 20, thereby pulling the lifting machine 20 upward. The procedure for introducing tension into the temporary cable 30 is carried out as steps a to d described above with reference to Figs. 14 to 17, 3 and 4, and the final adjusted target tension is introduced into the temporary cable 30.

[0057] (Step S3) Once the final adjusted target tension has been introduced into the temporary cable 30, the main girder block 80 that has been transported below the installation position is lifted by the crane 20, as shown in Figure 21. When the area below the installation position is a body of water, the main girder block 80 is generally transported below the installation position by barge. When the area below the installation position is on land and the size of the main girder block 80 is too large to transport using a normal trailer, the main girder block 80 may be assembled by connecting the main girder blocks transported in sections below the installation position.

[0058] (Step S4) As shown in Figure 22, the main girder block 80 is lifted up to the same height as the already installed main girder 106. The lifted main girder block 80 is joined to the already installed main girder 106 and connected to the main tower 102 by the permanent cable 104.

[0059] When the erection of one main girder block 80 is completed up to step S4, the process returns to step S1 and the erection of the next main girder block 80 is carried out.

[0060] In the cable-stayed bridge erection method according to this embodiment, the temporary cable 30 applies a force having a vertically upward component to the crane 20, pulling the crane 20 upward. This makes it possible to erect a main girder block 80, which is made by connecting two main girder blocks of a size equivalent to that used in conventional erection methods, and significantly shortens the overall construction period compared to conventional methods. Furthermore, as shown in Figures 18 to 22, the cable-stayed bridge erection method according to this embodiment makes it possible to proceed with construction simultaneously on both sides of the cable-stayed bridge 100, which also shortens the overall construction period.

[0061] Therefore, by using the cable-stayed bridge construction method according to this embodiment, the overall construction period for the cable-stayed bridge can be shortened, and for cable-stayed bridges constructed in water areas, the number of navigation restrictions can also be reduced.

[0062] (3) Supplementary information In the cable-stayed bridge erection device 10 according to an embodiment of the present invention, the methods for introducing tension into the temporary cable 30 and for securing it have been specifically described, but the methods for introducing tension into the temporary cable 30 and for securing it are not limited to the specific examples described.

[0063] For example, in the cable-stayed bridge erection device 10 according to an embodiment of the present invention, one end of the temporary cable 30 is configured to be fixed to the main tower side anchoring section 40, but it may also be configured to be fixed to the installed main girder 106, the ground, etc.

[0064] Furthermore, in the cable-stayed bridge 100, the embodiments of the present invention have been explained on the assumption that the main girder blocks 80 and the installed main girders 106 are anchored to the main tower 102 by the permanent cables 104. However, the present invention can also be applied to a type of cable-stayed bridge in which a through saddle portion through which the permanent cables pass is formed in the main tower, the permanent cables passed through the through saddle portion are tensioned and anchored at the anchoring portions of the main girder blocks arranged on the left and right sides of the main tower, and the permanent cables are subjected to a force having a vertically upward component from the main tower, thereby supporting the main girder blocks on the main tower.

[0065] Furthermore, as explained in the description of the cable-stayed bridge erection device 10 according to an embodiment of the present invention, the deflector 20F and the main tower top deflector 32 have the function of changing the extension direction of the temporary cable 30, and can be said to be angle-changing members that change the extension direction of the temporary cable 30.

[0066] In addition, in the drawings (Figures 3, 4, 10, 11, etc.), the deflector 20F and the main tower top deflector 32 have semicircular plates attached to their ends to prevent the temporary cable 30 from falling off the deflector 20F and the main tower top deflector 32. However, the deflector 20F and the main tower top deflector 32 are not limited to this shape, and may, for example, be structured with a pin of some length and the semicircular plate removed. If the deflector 20F and the main tower top deflector 32 are structured with such a pin, the temporary cable 30 can slide to some extent along the longitudinal direction of the outer peripheral surface of the pin, preventing the temporary cable 30 from coming into contact with the semicircular plate and causing local bending or stress concentration in the temporary cable 30. [Explanation of symbols]

[0067] 10... Cable-stayed bridge erection equipment 20...lifting machine 20A...Main unit 20A1...Long beam member 20A2…Horizontal beam 20A3...Tip side section 20B...hanging part 20B1, 20B2…Fixed pulley 20B3…Moving pulley 20C...winch 20D...Wire 20E...fixing part 20E1...Center hole jack 20E2…Ram Chair 20F…Deflection tool 20G…Fixed equipment 30...Temporary cable 30A...Temporary extension cable 30B...tension rod 30C...Cable socket 32…Main tower top deflector 40...Main tower side anchorage 42...Lower bracket 42A, 42B, 46A, 46B...Reinforcing members 44...winch 46...Upper bracket 48...Center hole jack 50...Ram Chair 80...Main girder block 100…Cable-stayed bridge 102…Main tower 104...Permanent cable 106...Main girder already installed 106A...tip 110...Bridge pier 112...Diagonal vent

Claims

1. A method for erecting a cable-stayed bridge having main towers and main girders, comprising: a main girder supporting step of applying a force having a vertically upward component to the main girder using a first cable that receives a force having a vertically upward component from the main tower to support the main girder; a lifting machine placement process of placing a lifting machine at a predetermined position on the main girder; a tension introducing step of introducing tension into a second cable connecting the tip end portion of the lifting machine arranged at the predetermined position and the main tower so that a force having a vertically upward component is applied to the lifting machine; a lifting process in which, after the tension introducing process, the main girder block installed on the tip side of the main girder in a direction away from the main tower is lifted to a predetermined height by the lifting machine; a main girder block support process in which the main girder block lifted to the predetermined height in the lifting process is joined to the tip of the main girder, and a force having a vertically upward component is applied to the main girder block lifted to the predetermined height in the lifting process by a third cable that receives a force having a vertically upward component from the main tower, thereby supporting the main girder block as part of a new main girder; Equipped with In the tension introduction step, the extension direction of the second cable is changed between the fixing portion at the tip side portion of the lifting machine and the fixing portion at a portion other than the lifting machine in a direction different from the extension direction of a straight line connecting the fixing portion at the tip side portion of the lifting machine and the fixing portion at a portion other than the lifting machine, and the tension is introduced; A method for erecting a cable-stayed bridge, characterized in that the extension direction of the second cable in the tension introduction process is changed by an angle change member provided on the crane.

2. 2. The method for erecting a cable-stayed bridge as described in claim 1, characterized in that the position of the tip end portion of the lifting machine to which the second cable is connected is located farther from the main tower than the portion of the main girder to which the vertical downward load of the lifting machine is applied.

3. The tension introduction section on the lifting machine side that introduces tension into the second cable and the fixing section of the second cable to the tip side section of the lifting machine are located closer to the end of the second cable on the lifting machine side than the section of the second cable that contacts the angle change member provided on the lifting machine, 2. The cable-stayed bridge erection method according to claim 1, characterized in that the lifting step is carried out after final adjustment of the tension of the second cable is made by the lifting machine side tension introduction section in the tension introduction step.

4. A method for erecting a cable-stayed bridge having main towers and main girders, comprising: a main girder supporting step of applying a force having a vertically upward component to the main girder using a first cable that receives a force having a vertically upward component from the main tower to support the main girder; a lifting machine placement process of placing a lifting machine at a predetermined position on the main girder; a tension introducing step of introducing tension into a second cable connecting the tip end portion of the lifting machine arranged at the predetermined position and the main tower so that a force having a vertically upward component is applied to the lifting machine; a lifting process in which, after the tension introducing process, the main girder block installed on the tip side of the main girder in a direction away from the main tower is lifted to a predetermined height by the lifting machine; a main girder block support process in which the main girder block lifted to the predetermined height in the lifting process is joined to the tip of the main girder, and a force having a vertically upward component is applied to the main girder block lifted to the predetermined height in the lifting process by a third cable that receives a force having a vertically upward component from the main tower, thereby supporting the main girder block as part of a new main girder; Equipped with In the tension introduction step, the extension direction of the second cable is changed between the fixing portion at the tip side portion of the lifting machine and the fixing portion at a portion other than the lifting machine in a direction different from the extension direction of a straight line connecting the fixing portion at the tip side portion of the lifting machine and the fixing portion at a portion other than the lifting machine, and the tension is introduced; A method for erecting a cable-stayed bridge, characterized in that the extension direction of the second cable during the tension introduction process is changed by an angle change member provided on the main tower and also by an angle change member provided on the lifting machine.

5. A method for erecting a cable-stayed bridge as described in Claim 4, characterized in that the position of the tip portion of the lifting machine to which the second cable is connected is located farther from the main tower than the portion of the main girder to which the vertical downward load of the lifting machine is applied.

6. a lifting machine side tension introduction section that introduces tension into the second cable and the fixing section of the second cable to the tip side section of the lifting machine are located closer to the end of the second cable on the lifting machine side than a section of the second cable that contacts the angle change member provided on the lifting machine, A cable-stayed bridge erection method as described in claim 4, characterized in that the lifting process is carried out after final adjustment of the tension of the second cable is made by the lifting machine side tension introduction section in the tension introduction process.

7. A method for erecting a cable-stayed bridge as described in any one of claims 4 to 6, characterized in that in the tension introduction process, the extension direction of the second cable is changed by the angle change member provided on the main tower of the cable-stayed bridge, and the second cable is fixed at a position below the angle change member and tension is introduced.

8. a tension releasing step of releasing tension on the second cable after the main girder block supporting step; a cable separating step of separating the second cable midway after the tension releasing step; a lifting machine relocation process for relocating the lifting machine to a predetermined position on the new main girder formed by joining and supporting the main girder block in the main girder block support process after the cable separation process; a cable joining step of joining a cable to the second cable separated in the cable separating step to form an extended second cable having an increased overall length; a tension reintroduction step of introducing tension into the second cable after the extension, the total length of which has been increased in the cable extension step; a second lifting step of lifting the main girder block to be erected as a main girder member of the cable-stayed bridge to a predetermined height using the lifting machine relocated in the lifting machine relocation step after the tension reintroduction step; a second main girder block support process in which the main girder block lifted to the predetermined height in the second lifting process is joined to the new main girder, and a fourth cable that receives a force having a vertically upward component from the main tower applies a force having a vertically upward component to the main girder block lifted to the predetermined height in the second lifting process, thereby supporting the main girder block as part of the new main girder; The cable-stayed bridge erection method according to any one of claims 1 to 6, characterized in that it comprises:

9. a tension releasing step of releasing tension on the second cable after the main girder block supporting step; a cable separating step of separating the second cable midway after the tension releasing step; a lifting machine relocation process for relocating the lifting machine to a predetermined position on the new main girder formed by joining and supporting the main girder block in the main girder block support process after the cable separation process; a cable joining step of joining a cable to the second cable separated in the cable separating step to form an extended second cable having an increased overall length; a tension reintroduction step of introducing tension into the second cable after the extension, the total length of which has been increased in the cable extension step; a second lifting step of lifting the main girder block to be erected as a main girder member of the cable-stayed bridge to a predetermined height using the lifting machine relocated in the lifting machine relocation step after the tension reintroduction step; a second main girder block support process in which the main girder block lifted to the predetermined height in the second lifting process is joined to the new main girder, and a fourth cable that receives a force having a vertically upward component from the main tower applies a force having a vertically upward component to the main girder block lifted to the predetermined height in the second lifting process, thereby supporting the main girder block as part of the new main girder; The method for erecting a cable-stayed bridge according to claim 7, characterized in that the extending direction of the second cable to which tension has been introduced in the tension reintroduction process is changed by the angle changing member provided on the main tower, and the second cable is fixed at a position below the angle changing member and tension is introduced thereto.

10. A lifting machine used for erecting the main girder of a cable-stayed bridge having a main tower, capable of moving on the main girder, A lifting unit that lifts the main girder block erected as a main girder member of the cable-stayed bridge from below at a predetermined position on the tip side of the main girder; a cable connection portion, which is a tip side portion of the lifting machine, capable of fixing a cable that can receive a force having a vertically upward component from the main tower and apply a force having a vertically upward component to the lifting machine; Equipped with A lifting machine characterized by having an angle change member that changes the direction in which the cable extends to a direction different from the direction in which a straight line extends connecting the cable connection portion and the portion of the cable that receives a force having a vertically upward component from the main tower.

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