JP2018123643A - Slab replacing method for composite girder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slab replacement method for a composite girder capable of closing a clearance between an existing slab and a new slab without generating any steps on a road surface.SOLUTION: A top surface of a plate-like member 50 closing clearance between an existing slab 20 and a new slab 30 becomes flush with top surfaces of pavements 22, 23, so as to form that a road surface which does not have any step between slabs 20, 30 by the plate-like member 50, so that traveling vehicles passing on the plate-like member 50 are not subject to impact. In this case, since pre-stressed concrete made of ultrahigh strength fiber reinforced concrete is used for the plate-like member 50, prestress is applied to the plate-like member 50 to suppress tensile stress at the time of loading, and also the ultrahigh strength fiber reinforced concrete enhances tensile strength and toughness of concrete itself.SELECTED DRAWING: Figure 22

Description

  The present invention relates to a composite slab floor slab replacement method for removing an old floor slab from an existing bridge made of a composite girder and replacing it with a new floor slab.

  Conventionally, a composite girder in which a steel girder and a concrete slab are integrated is used for many bridges such as ordinary roads and highways. A composite girder combines a main girder and a floor slab by embedding a plurality of slip stoppers provided on an upper flange of the main girder in a concrete floor slab.

  By the way, when the floor slab is deteriorated in the existing bridge, the floor slab replacement construction is performed in which the existing floor slab is removed from the main girder and a new floor slab is reconstructed. In this case, since continuous traffic interruption for a long period is not preferable, replacement work may be performed for each section using a time zone with a small traffic volume such as nighttime. In such replacement construction, a part of the existing floor slab is removed at night and then a new floor slab is installed in the removal section of the existing floor slab to open traffic during the daytime. At that time, the vehicle is allowed to travel by closing the gap between the existing floor slab remaining on the main girder and the new floor slab with a lining plate.

  In the composite girder, when a load is loaded on the floor slab, compressive stress is generated in the upper flange of the main girder and tensile stress is generated in the lower flange, but in the composite girder, the main girder and the floor slab are integrated. Since an axial force in the bridge axis direction is generated in this state, the neutral axis of the bending stress is closer to the upper flange than the non-synthetic beam. Accordingly, even if a part of the existing floor slab is removed and a new floor slab is installed, a non-synthetic structure is obtained if the floor slabs are not continuous with a gap. That is, since the axial force is not transmitted between the floor slabs due to the gap between the existing floor slab remaining on the main girder and the new floor slab, bending stress is generated only on the main girder, and the neutral axis of the bending stress is Move to the lower flange side of the main girder. Thereby, the compressive stress on the upper flange side increases, and there is a possibility that the stress will be exceeded due to the load during traffic opening.

  Therefore, conventionally, an axial force transmission device using a hydraulic jack is disposed in the gap between the end surface of the existing floor slab and the end surface of the new floor slab, and the axial force transmission device separates the end surfaces of the floor slabs from each other. By applying the pressing force, the axial force in the bridge axis direction is transmitted between the existing floor slab and the new floor slab (see, for example, Patent Document 1 or 2). Thereby, a tensile stress is forcibly generated on the upper flange side of the main girder, and the compressive stress of the upper flange at the time of loading is reduced, thereby suppressing the excess stress.

JP-A-63-64565 JP 2005-282272 A

  By the way, the covering plate that closes the gap between the existing floor slab and the new floor slab needs to be strong enough to withstand the load during vehicle travel. However, when a concrete board is used as the lining board, the thickness dimension becomes large, and a large step is generated between the road surface. As a result, an impact is generated on the traveling vehicle when overcoming the level difference due to the lining plate, so it is necessary to ensure safety by slowing down by speed regulation, and traffic congestion due to slow driving occurs when there is a lot of traffic There was a problem.

  The present invention has been made in view of the above problems, and the object of the present invention is to provide a composite girder that can close a gap between an existing floor slab and a new floor slab without causing a step on the road surface. The purpose is to provide a floor slab replacement method.

  In order to achieve the above object, the present invention, after removing a part of the existing floor slab in the bridge axis direction on the main girder, installs a new floor slab in the removed section of the existing floor slab and remains on the main girder After applying axial force in the bridge axis direction to the end face of each floor slab by the axial force transmission device arranged between the end faces of the existing floor slab and the new floor slab, the gap between each floor slab is closed by a plate-like member In the composite girder floor slab replacement method that enables passage between the floor slabs, the plate-like member is made of prestressed concrete made of ultra-high strength fiber reinforced concrete, and the bridge floor direction of the existing floor slab An existing floor slab is formed so that a non-paved portion without pavement is formed at the end, and the plate-like member formed to have a thickness dimension equal to or less than the thickness of the pavement has an upper surface equal to the upper surface of the pavement. Between the floor slabs and the new floor slab. And so as to close the by the plate-like member.

  As a result, since the upper surface of the plate member that closes the gap between the existing floor slab and the new floor slab has the same height as the upper surface of the pavement, the road surface without steps between the floor slabs by the plate member. Is formed, and the traveling vehicle passing through the plate-like member is not subjected to an impact due to a step. In this case, prestressed concrete made of ultra-high strength fiber reinforced concrete is used for the plate-like member, so that prestress is applied to the plate-like member, so that tensile stress during loading is suppressed and ultra-high strength is also provided. Fiber reinforced concrete increases the tensile strength and toughness of the concrete itself.

  According to the present invention, there is no impact caused by a step on a traveling vehicle that passes through a plate-like member that closes the gap between the existing floor slab and the new floor slab, so that the vehicle can travel safely and the step Therefore, it is not necessary to drive slowly, and traffic congestion due to slow driving can be avoided. In this case, the prestress is applied to the plate-like member, so that the tensile stress during loading is suppressed and the tensile strength and toughness of the concrete itself is enhanced by the ultra-high-strength fiber reinforced concrete. It can be formed in a thickness dimension smaller than the thickness of the pavement while ensuring a sufficient strength, and even when the thickness dimension is small, a sufficient strength against a vertical load and an impact by a traveling vehicle can be obtained.

The top view of the composite girder which shows the floor slab replacement | exchange process which shows one Embodiment of this invention Top view of composite girder showing floor slab replacement process X-X arrow direction sectional view of the composite girder Main part enlarged plan view of composite girder showing floor slab replacement process Exploded perspective view of axial force transmission device and fixing member Plan view of plate member Front view of plate member YY arrow direction sectional view of a plate-like member Front sectional view of main parts of plate-like member Side view of composite girder showing floor slab replacement process Side view of composite girder showing floor slab replacement process Side view of composite girder showing floor slab replacement process Side view of composite girder showing floor slab replacement process Composite perspective view showing floor slab replacement process Composite perspective view showing floor slab replacement process Composite perspective view showing floor slab replacement process Composite perspective view showing floor slab replacement process Expanded side view of the main part of the composite girder showing the floor slab replacement process Expanded side view of the main part of the composite girder showing the floor slab replacement process Expanded side view of the main part of the composite girder showing the floor slab replacement process Expanded side view of the main part of the composite girder showing the floor slab replacement process Expanded side view of the main part of the composite girder showing the floor slab replacement process Plan view showing analysis model of plate-like member The figure which shows the physical property value of the analytical model of the plate-like member The figure which shows the analysis result of the plate-like member The figure which shows the analysis result of the plate-like member The figure which shows the comparison result of the weight of the plate-like member The figure which shows the confirmation result of the ultimate strength of the weight of a plate-shaped member

  FIGS. 1 to 28 show an embodiment of the present invention, and show a floor slab replacement method for removing an old floor slab from an existing bridge made of composite girders and replacing it with a new floor slab. .

  The floor slab replacement method of the present embodiment is such that, in the composite girder 1, after removing a section in the bridge axis direction of the existing floor slab 20 on the main girder 10, the new floor slab 30 is placed in the removal section of the existing floor slab 20. The axial force transmission device 40 installed and installed between the end surfaces of the existing floor slab 20 and the new floor slab 30 remaining on the main girder 10 applies a pressing force in the bridge axis direction to the end surface of each floor slab, This is a construction method that allows passage between the floor slabs 20 and 30 by closing the gap between the floor slabs 20 and 30 with a plurality of plate-like members 50. Each plate-like member 50 is fixed to the floor slabs 20 and 30 by a plurality of fixing members 60.

  The main girder 10 is made of a steel girder having an upper flange 12 and a lower flange 13 at the upper end and lower end of the web 11, respectively, and is arranged in a plurality of rows (for example, three rows) at intervals in the direction perpendicular to the bridge axis.

  The existing floor slab 20 is made of a concrete floor slab placed on the upper flange 12 of each main girder 10, and wall height columns 21 are provided on both sides in the width direction. An asphalt pavement 22 is provided on the existing floor slab 20.

  As the new floor slab 30, for example, a precast concrete floor slab manufactured at a factory is used, and wall height columns 31 are provided on both sides in the width direction. A plurality of new floor slabs 30 are placed on each main girder 10 so as to be aligned in the bridge axis direction, and the end of a PC steel bar (not shown) protruding from the bridge axis direction end of the new floor slab 30. By connecting the parts with a joint, the floor slabs are connected to each other. A plurality of inserts 32 for connecting the fixing member 60 are embedded in the lower surface of the new floor slab 30, and the inserts 32 are arranged at intervals in the direction perpendicular to the bridge axis.

  The axial force transmission device 40 includes a pair of reaction force bases 41 attached to the bridge axial direction end surfaces of the existing floor slab 20 and the new floor slab 30, and a plurality of hydraulic jacks 42 disposed between the reaction force bases 41. The hydraulic jacks 42 are arranged at equal intervals in the direction perpendicular to the bridge axis. The reaction force base 41 is made of H steel extending in the direction perpendicular to the bridge axis, and a plurality of reinforcing plates 41b are spaced from each other in the direction perpendicular to the bridge axis between a pair of flanges 41a spaced apart from each other in the bridge axis direction. Is provided. Each reaction force base 41 is fixed to the bridge axial direction end surfaces of the existing floor slab 20 and the new floor slab 30 by bolts 44 via a bearing plate 43. The hydraulic jack 42 includes a columnar jack main body 42a and a pressing rod 42b protruding from one axial end side of the jack main body 42a. The jack main body 42a abuts against the reaction force table 41 on the existing floor slab 20 side and presses. The rod 42b comes into contact with the reaction table 41 on the new floor slab 30 side. Each reaction force base 41 is provided with a plurality of jack bases 45 located below the respective hydraulic jacks 42. Each jack base 45 is composed of a plate-like member extending from the lower end of the reaction force base 41 to the lower side of the jack body 42a, and the front end side of the jack base 45 of one reaction force base 41 and the jack base 45 of the other reaction force base 41 is arranged. They overlap each other in the vertical direction.

  Each plate-like member 50 is formed in a rectangular plate shape, and is arranged between the floor slabs 20 and 30 in a direction perpendicular to the bridge axis. Each plate-like member 50 is made of prestressed concrete made of ultra high strength fiber reinforced concrete. Ultra-high-strength fiber reinforced concrete contains chemically reinforcing steel fibers, stainless steel fibers, organic fibers, or other reinforcing fibers in cement, and uses a reactive fine powder such as silica fume to make it chemically dense. A cured body is formed. As a result, the tensile strength and the high toughness can be obtained by the reinforcing fiber while having a compressive strength and durability much higher than those of ordinary concrete.

  Further, as shown in FIG. 6, the plate-like member 50 includes a plurality of PC steel materials 51 arranged at equal intervals in the long side direction and the short side direction of the plate-like member 50, and the PC steel material 51 is prestressed. It is molded by a concrete formwork in a state where is given. As the PC steel material 51, a tension material having a higher tensile strength than a reinforcing steel material such as a reinforcing bar is used. The PC steel material 51 arranged in the long side direction (the direction perpendicular to the bridge axis) of the plate-like member 50 is arranged below the PC steel material 51 arranged in the short side direction (the bridge axis direction) of the plate-like member 50. Yes. In this case, as shown in FIG. 9, the PC steel material 51 extending in the long side direction (the direction perpendicular to the bridge axis) of the plate-like member 50 is disposed in the center of the plate-like member 50 in the thickness direction (vertical direction). The height dimension H 1 from the PC steel material 51 extending in the short side direction (bridge axis direction) to the upper surface of the plate-like member 50 is larger than the height dimension H 2 to the lower surface of the plate-like member 50. That is, in the plate member 50, the PC steel material 51 extending in the short side direction is disposed below the center in the thickness direction (vertical direction) of the plate member 50. In this case, if the thickness H of the plate member 50 is 70 mm, it is preferable that H1 is 45 mm and H2 is 25 mm.

  Further, notches 50 a are provided at the four corners of the plate-like member 50. Each notch 50a is provided with a joint 52 for connecting the plate-like members 50 to each other. The joint 52 has a rod-like member 52a extending from one end embedded in the concrete of the plate-like member 50, thereby providing the plate-like member 50. It is fixed to. A plurality of inserts 53 for connecting the fixing member 60 are embedded in the lower surface of the plate-like member 50, and each insert 53 is arranged at equal intervals in the long-side direction substantially at the center side in the short-side direction of the plate-like member 50. Arranged in columns. Further, the upper surface of the plate-like member 50 is subjected to anti-slip processing. For example, when the plate-like member 50 is formed with a mold, this anti-slip processing is a die that forms a rough surface of the concrete before curing with a brush or the like, or forms the upper surface side of the plate-like member 50. It is applied by forming a large number of irregularities.

  Each fixing member 60 is formed of a steel material having an L-shaped cross section, and is disposed on the lower surface side of the existing floor slab 20 and the new floor slab 30 and is connected to the lower surface side of the plate-like member 50 by a plurality of connecting members 61. It is like that. The fixing member 60 has a length extending from the lower surface side of the existing floor slab 20 to the lower surface side of the new floor slab 30, and two holes 60 a through which the connecting member 61 is inserted are spaced apart in the longitudinal direction on the central side in the longitudinal direction. Is provided. Further, the fixing member 60 is connected to the lower surface side of the new floor slab 30 by bolts 62 screwed into the insert 32 of the new floor slab 30, and a bolt 62 is attached to one end side in the longitudinal direction of the fixing member 60. A hole 60b for insertion is provided. The connecting member 61 is made of a rod-like member having screw portions at least on both end sides, and the upper end side thereof is screwed into the insert 53 of the fixing member 60. Further, the lower end side of the connecting member 61 is inserted through the hole 60a of the fixing member 60, and the nut 63 is screwed from below.

  Next, the floor slab replacement method of this embodiment will be described. Here, for example, in the replacement work in which traffic is regulated at night and traffic is opened during the day, the existing floor slab 20 in a certain section has already been replaced with the new floor slab 30 as shown in FIG. I will explain from the state.

  First, after the traffic of the general vehicle A is blocked due to traffic restrictions, a part of the existing floor slab 20 on the main girder 10 in the bridge axis direction is removed as shown in FIG. At that time, after removing the axial force transmission device 40 and the plate member 50 between the newly installed floor slab 30 and the existing floor slab 20, the existing floor slab 20 is cut in a direction perpendicular to the bridge axis, and the crane Lift with car B and remove. Next, as shown in FIG. 12, the new floor slab 30 is installed in the removal section of the existing floor slab 20. At that time, a plurality of new floor slabs 30 are sequentially placed on the main girder 10 in the direction of the bridge axis by the crane vehicle B, and the new floor slabs 30 are connected to each other. Thereafter, as shown in FIG. 13, an axial force transmission device 40 is installed between the end surfaces of the existing floor slab 20 and the new floor slab 30 remaining on the main girder 10, and the end surface of each floor slab is formed by the axial force transmission device 40. A pressing force in the direction of the bridge axis is applied to the slab, and the gap between the floor slabs 20 and 30 is closed by the plate member 50, and then the traffic is released to allow the general vehicle A to pass.

  Here, the step of installing the axial force transmission device 40 between the existing floor slab 20 and the new floor slab 30 and the step of closing the gap between the floor slabs 20 and 30 by the plate-like member 50 will be described below. .

  First, as shown in FIG. 18, the pavement 22 of the existing floor slab 20 on the main girder 10 is removed from the edge of the floor slab by a length L in the bridge axis direction, and the existing floor slab 20 as shown in FIGS. 14 and 19. The non-paved portion 23 in which the pavement 22 does not exist is formed at the end of the plate.

  Next, the buffer members 70 are placed on the non-paved portion 23 of the existing floor slab 20 and the upper surface of the unpaved new floor slab 30, respectively. The buffer member 70 is made of a sheet-like rubber extending over almost the entire width of the floor slabs 20 and 30.

  Subsequently, each fixing member 60 is connected to the lower surface side of the new floor slab 30 by screwing bolts 62 into the inserts 32 of the new floor slab 30. Thereby, each fixing member 60 is attached so that the lower surface of the existing floor slab 20 and the lower surface of the new floor slab 30 may be covered.

  Next, as shown in FIG. 15, the axial force transmission device 40 is installed between the end surface of the existing floor slab 20 and the end surface of the new floor slab 30. That is, the reaction force base 41 of the axial force transmission device 40 is attached to the end surface of the existing floor slab 20 and the end surface of the new floor slab 30 as shown in FIG. 19, and the reaction on the existing floor slab 20 side as shown in FIG. A hydraulic jack 42 is disposed between the force table 41 and the reaction force table 41 on the new floor slab 30 side. Subsequently, by driving the hydraulic jack 42 and applying a pressing force in the direction away from each reaction table 41, an axial force in the bridge axis direction is applied to the end surface of the existing floor slab 20 and the end surface of the new floor slab 30. To do.

  Next, as shown in FIG. 21, the plate-like member 50 is placed from above so as to extend over the existing floor slab 20 and the new floor slab 30. At that time, one end side in the bridge axis direction of the plate member 50 is placed on the non-paved portion 23 of the existing floor slab 20 via one buffer member 70, and the other end side in the bridge axis direction of the plate member 50 is not yet opened. It is placed on the upper surface of the newly installed floor slab 30 of the pavement through the other buffer member 70. In this case, the thickness H of the plate-like member 50 is formed smaller than the thickness t of the pavement 22 by the thickness of the buffer member 70 (for example, H = 70 mm, t = 80 mm). When the plate-like member 50 is placed on the upper surface, the upper surface of the plate-like member 50 and the upper surface of the pavement 22 have the same height. The buffer member 70 is formed such that the thickness dimension in the unloaded state is increased by the amount compressed by the load of the plate-like member 50.

  As shown in FIG. 16, the plate-like members 50 are arranged side by side in the direction perpendicular to the bridge axis, and are connected to each other in the direction perpendicular to the bridge axis by a joint 52. Then, the upper end side of the fixing member 61 is screwed into the insert 53 of the plate-like member 50, the lower end side of the connecting member 61 is inserted into the hole 60 a of the fixing member 60, and the nut 63 is inserted into the lower end side of the connecting member 61 from below. 17 and 22, the plate-like member 50 is fixed to the existing floor slab 20 and the new floor slab 30, and the plate-like member 50 connects the existing floor slab 20 and the new floor slab 30. The gap between them is closed. Further, a gap between the wall height column 21 of the existing floor slab 20 and the wall height column 31 of the new floor slab 30 is covered with a temporary protective fence 80.

  Then, by forming a pavement 33 having the same thickness as the pavement 22 of the existing floor slab 20 on the new floor slab 30, a road surface having no step is formed between the existing floor slab 20 and the new floor slab 30. .

  As described above, according to the floor slab replacement method of the present embodiment, the non-paved portion 23 having no pavement is formed at the end portion in the bridge axis direction of the existing floor slab 20, and the thickness dimension is equal to or less than the thickness of the pavement 22. Is placed on the non-paved portion 23 of the existing floor slab 20 and the new floor slab 30 so that the upper surface of the plate-like member 50 is at the same height as the upper surface of the pavement 22. Since the gap between the plates 20 and 30 is closed by the plate-like member 50, a road surface having no step can be formed between the floor plates 20 and 30. As a result, the traveling vehicle passing through the plate-like member 50 is not subjected to an impact due to a step, so that it is possible to travel safely and there is no need for slow driving for the step, and traffic congestion due to slow traveling occurs. Can be avoided.

  In this case, since the prestressed concrete made of ultra-high strength fiber reinforced concrete is used for the plate-like member 50, the plate-like member 50 is formed in a thickness dimension smaller than the thickness of the pavement 22 while ensuring the necessary strength. be able to. That is, since the plate-like member 50 has a double-end support beam structure in which both ends are supported by the existing floor slab 20 and the new floor slab 30, a tensile stress is applied to the lower edge side of the center of the span of the plate-like member 50 due to the load of the traveling vehicle. Although concentrated, the plate-like member 50 is prestressed by the PC steel material 51, so that the tensile stress at the time of loading is suppressed, and the tensile strength and toughness of the concrete itself are high due to the ultra high strength fiber reinforced concrete. It becomes a structure. Therefore, the plate-like member 50 not only has a pre-stress structure, but also uses ultra-high-strength fiber reinforced concrete, thereby obtaining sufficient strength against vertical loads and impacts by the traveling vehicle even if the thickness dimension is small. be able to.

  Furthermore, since the PC steel materials 51 arranged in the long side direction of the plate-like member 50 are arranged below the center in the thickness direction (vertical direction) of the plate-like member 50, The compressive stress of the arranged PC steel members 51 can be generated so that the lower edge side is larger than the upper edge side of the plate-like member 50, and the strength of the plate-like member 50 where tensile stress is generated when loaded is increased. be able to.

  Further, a fixing member 60 for fixing the plate member 50 to the floor slabs 20, 30 is arranged on the lower surface side of each floor slab 20, 30, and the fixing member 60 and the plate member 50 are moved up and down by the fastening member 61. Since the plate-like member 50 is fixed to the floor slabs 20 and 30 by fastening from the direction, the plate-like member 50 is not lifted upward by an impact from a traveling vehicle, and a road surface without a step is ensured. Can be kept in.

  Further, since the gaps between the floor slabs 20 and 30 are closed by the plurality of plate-like members 50 arranged in the direction perpendicular to the bridge axis, the number of plate-like members 50 corresponding to the width of the floor slab at each construction site. The gap between the floor slabs can be closed using, and versatility can be improved.

  In this case, since the plate members 50 are connected to each other in the direction perpendicular to the bridge axis by the joint 52, the plate members 50 are not individually displaced in the direction perpendicular to the bridge axis. Generation | occurrence | production of the clearance gap between each plate-shaped member 50 by an impact etc. can be prevented.

  Moreover, since the upper surface of the plate-like member 50 is subjected to anti-slip processing, it is possible to effectively prevent the traveling vehicle from slipping and to improve safety.

  Furthermore, since the plate-like member 50 is placed on the non-paved portion 23 of the existing floor slab 20 and the upper surface of the new floor slab 30 via the buffer member 70, vibrations and impacts from the traveling vehicle are caused by the buffer member 70. Can be absorbed. Thereby, while being able to reduce the impact load to the plate-shaped member 50, generation | occurrence | production of the noise at the time of vehicle passage can also be suppressed.

  In the above embodiment, since the buffer member 70 is interposed between the plate-like member 50 and each floor slab 20, 30, the plate-like member 50 is formed to have a thickness dimension smaller than the thickness of the pavement 22. However, the plate-like member 50 is formed to have a thickness dimension equivalent to the thickness of the pavement 22, and the plate-like member 50 is directly placed on each floor slab 20, 30 without using the buffer member 70. Also good.

  Moreover, about the plate-shaped member used for the floor slab replacement method of this invention, the plate-shaped member of Example 1 is the floor | bed of this invention by performing a strength analysis with respect to the following Example 1 and Comparative Examples 1 and 2. It was confirmed that it had the strength to be used for the plate replacement method.

  Example 1 of the present invention is prestressed concrete (hereinafter referred to as UFCPC board) made of ultra-high strength fiber reinforced concrete, Comparative Example 1 is prestressed concrete (hereinafter referred to as PC board) made of ordinary concrete, and comparative example. A steel plate was used for 2. In this case, as shown in FIG. 23, the plate-like member M used in this test is formed with a vertical (short side) dimension of 1150 mm and a horizontal (long side) dimension of 2000 mm, and 100 mm from both ends of the short side. A load is loaded at a loading position P in the range of 200 mm × 500 mm in the center with the position of as the fulcrum R. In this case, each fulcrum R has a span length of 950 mm, corresponds to the position of the buffer member 70 of the above-described embodiment, and extends in the long side direction from both ends of the long side to the position of 100 mm. The thickness H of the plate-like member M is 70 mm in Example 1 and Comparative Example 1, and 30 mm or 36 mm in Comparative Example 2. The physical properties of the plate member M are shown in FIG.

  In this strength analysis, the following analysis was performed by FEM (finite element method) structural analysis using the plate-like member M as an analysis model.

  First, Example 1 and Comparative Examples 1 and 2 were analyzed for stress when a load of 100 kN was loaded at the loading position P of the plate-like member M.

  As a result of the analysis, as shown in FIG. 25, it was confirmed that the upper edge stress level and the lower edge stress level did not exceed the allowable stress level for Example 1 and Comparative Example 2 and had the required strength. It was. On the other hand, in Comparative Example 1, both the upper edge stress level and the lower edge stress level exceeded the allowable stress level, and the result was that the required strength was not obtained. In addition, the maximum displacement was smaller in Example 1 than in Comparative Examples 1 and 2.

  Next, in consideration of the impact load, the stress when the load 140 kN was loaded at the loading position P of the plate member M was analyzed for Example 1 and Comparative Example 2. In addition, since the comparative example 1 of PC board did not have required intensity | strength in the analysis of load 100kN, it excluded from the analysis object of load 140kN.

  As a result of the analysis, as shown in FIG. 26, for Example 1 and Comparative Example 2, neither the upper edge stress level nor the lower edge stress level exceeds the allowable stress level and has the required strength. Was confirmed. The maximum displacement was smaller in Example 1 than in Comparative Example 2.

  Here, when the weights of Example 1 and Comparative Example 2 were compared, as shown in FIG. 27, the weight per sheet member M was 402.2 kg in Example 1 and 650.1 in Comparative Example 2. Example 1 weighed about 2/3 of Comparative Example 2.

  From the above, Example 1 of the UFCPC board has the required strength even when formed to a thickness of 70 mm, which is smaller than a typical pavement thickness of 80 mm, and the required strength is insufficient at a thickness of 70 mm as in Comparative Example 1. The result that it was excellent in intensity | strength was obtained with respect to PC board to do. Moreover, the result that the Example 1 of the UFCPC board was superior to the comparative example 2 of the steel sheet in terms of light weight and less deflection was obtained.

  Furthermore, about Example 1, the ultimate proof stress at the time of loading 200kN in the loading position P was confirmed. As a result, as shown in FIG. 28, it was confirmed that the generated bending moment was not more than the fracture resistance bending moment even for 200 kN.

  DESCRIPTION OF SYMBOLS 1 ... Composite girder, 10 ... Main girder, 20 ... Existing floor slab, 22 ... Pavement, 23 ... Non-paved part, 30 ... Newly installed floor slab, 33 ... Pavement, 40 ... Axial force transmission device, 50 ... Plate member, 60 ... fixing member, 70 ... buffer member.

Claims (6)

After removing a section of the existing floor slab on the main girder in the direction of the bridge axis, a new floor slab is installed in the removed section of the existing floor slab, and the end face of the existing floor slab remaining on the main girder and the new floor slab Passing between floor slabs is possible by applying an axial force in the bridge axis direction to the end face of each floor slab by the axial force transmission device placed between them, and then closing the gap between each floor slab with a plate-like member In the composite girder floor slab replacement method,
While using prestressed concrete made of ultra high strength fiber reinforced concrete for the plate-like member,
Forming a non-paved portion where there is no pavement at the bridge axial direction end of the existing floor slab,
The plate-like member formed to have a thickness dimension equal to or less than the thickness of the pavement is placed over the non-paved portion of the existing floor slab and the new floor slab so that the upper surface of the plate member has the same height as the upper surface of the pavement. The composite girder floor slab replacement method is characterized in that the gap between the floor slabs is closed by a plate-like member. A fixing member for fixing the plate member to the floor slab is disposed on the lower surface side of the floor slab, and the plate member is fixed to the floor slab by fastening the fixing member and the plate member from above and below by the fastening member. The floor replacement method for a composite girder according to claim 1, wherein: The composite slab floor slab replacement method according to claim 1 or 2, wherein the gaps between the floor slabs are closed by a plurality of plate-like members arranged in a direction perpendicular to the bridge axis. The said plate-like member is mutually connected in a bridge axis orthogonal direction. The floor slab replacement method of the synthetic girder of Claim 3 characterized by the above-mentioned. 5. The composite girder floor slab replacement method according to claim 1, wherein an anti-slip process is applied to an upper surface of the plate-like member. 6. The composite girder floor slab remover according to claim 1, wherein the plate-like member is placed on a non-paved portion of an existing floor slab and an upper surface of a new floor slab via a buffer member. Replacement method.

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