Expansion device for bridges using precast concrete members and its construction method

Abstract

To improve productivity and ensure quality at construction sites for the new installation and repair of an expansion device for bridges.SOLUTION: An expansion device for bridges attached to a road structure via a PCa pedestal 50 is configured such that the PCa pedestal 50 comprises: a lower pedestal 60 fixed to the road structure; and an upper pedestal 70, detachably attached to the upper part of the lower pedestal 60, on which an expansion device body 10 is placed. The lower pedestal 60 is fixed to the road structure when the expansion device body 10 is replaced. The upper pedestal 70 is removed from the lower pedestal 60 when replacing the expansion device body 10. The lower pedestal 60 and the upper pedestal 70 can be configured to be attached and detached by a one-pass type joint 40.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a bridge expansion device and its construction method, and more particularly to a bridge expansion device using a precast concrete member in which a separated precast concrete base is used and the bridge expansion device is installed on the precast concrete base, and its construction method. [Background technology]

[0002] Bridge expansion joints are subject to wear and tear caused by vehicle traffic, and therefore must be replaced and repaired on a timely basis. Traditionally, the removal of bridge expansion joints for replacement and repair has been performed manually using breakers or other tools. This chipping work generates noise from the breakers. Furthermore, the boundary between the part to be removed and the substructure is often unclear, which can unnecessarily damage the substructure and affect the integrity of the bridge. Furthermore, in order to secure the bridge expansion joint to the deck and substructure, numerous anchors are installed in the deck to secure the bridge expansion joint. Replacement and repair requires cutting all of the anchors, making the work cumbersome.

[0003] Various technologies have been proposed in the past to make it easier to install bridge expansion devices (see, for example, Patent Documents 1 and 2). The technology described in Patent Document 1 relates to a bridge expansion device that simplifies installation work so that it can be completed in a short time. This bridge expansion device has anchoring parts that protrude from the ends of the opposing bridges in advance. The bridge expansion device is then placed on the top surface of the anchoring parts, and fixing bolts that pass vertically through the mounting holes in the mounting parts at both ends of the bridge expansion device and the through-holes in the anchoring parts are screwed into fixing nuts to fasten and fix the bridge expansion device to the anchoring parts.

[0004] The technology described in Patent Document 1 allows the bridge expansion device to be attached by placing it on anchorages protruding from each of the opposing ends of the bridge and fixing it in place with fastening means, which simplifies the work process by eliminating the need for reinforcing steel bar arrangement, welding work, and post-cast concrete placement work.

[0005] The technology described in Patent Document 2 relates to a block-type buried joint expansion device for bridges that can be easily assembled, newly installed, and repaired using components manufactured in a factory or other facility off-site. This block-type buried joint expansion device for bridges consists of buried joints divided into multiple pieces that are placed across the entire roadway in the area where the RC deck is to be chipped. A groove of a specified dimension is formed on the back surface (back face) of each block-type buried joint at a specified width in the longitudinal direction. The bridge expansion device is installed by setting a thin plate-shaped adjustment metal fitting into this groove.

[0006] The block-type buried joint expansion device for bridges described in Patent Document 2 is easy to transport to the site, reduces the amount of work required for installation, and enables repair work and new construction work to be carried out in a short period of time. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-315090 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-40052 Summary of the Invention [Problem to be solved by the invention]

[0008] As mentioned above, with conventional technology, when removing an existing bridge expansion joint, chipping work using a breaker or other tool causes unnecessary damage to the existing deck slab and substructure. Furthermore, because the removal of a bridge expansion joint generates noise, methods for reducing noise are necessary. Furthermore, a large number of anchors are required to secure the bridge expansion joint to the deck, making the work complicated not only during removal but also during installation. Furthermore, the majority of construction work, whether repair or new construction, is done manually, and the quality and durability of the work generally depend on the quality of the work performed during construction. Furthermore, the aging of skilled workers makes it difficult to secure workers.

[0009] The present invention has been proposed in light of the above-mentioned circumstances, and aims to provide a bridge expansion joint and its construction method that uses precast concrete members, which enables improved productivity and quality assurance at construction sites when installing and repairing bridge expansion joints. [Means for solving the problem]

[0010] The bridge expansion device using Pca members and its construction method according to the present invention have the following features in order to achieve the above-mentioned objectives.

[0011] The expansion device for bridges and the construction method thereof according to the present invention are configured to install a PCa base on a road structure (for example, a deck slab). The expansion device body was installed. This relates to a bridge expansion device and its construction method. This PCa base consists of a lower base that is fixed to the road structure, It is formed separately from the lower base, It consists of an upper base that is detachably attached to the top of the lower base and on which the expansion device main body is placed.

[0012] When replacing the expansion device main body, the lower pedestal is fixed to the road structure, and when replacing the expansion device main body, the upper pedestal is detached from the lower pedestal. That is, when attaching the expansion device main body to the road structure, the lower pedestal is fixed to the road structure, the upper pedestal is attached to the top of the lower pedestal, and the expansion device main body is attached to the top of the upper pedestal. When replacing the expansion device main body, the upper pedestal and the expansion device main body attached to the top of the lower pedestal are detached while the lower pedestal remains fixed to the road structure, thereby replacing the expansion device main body.

[0013] Furthermore, the bridge expansion device and its construction method configured as described above can be provided with a one-pass joint for attaching and detaching the upper base to the lower base. In other words, the lower base and the upper base can be attached and detached by the one-pass joint. This one-pass joint consists of a female member and a male member. The female member has a recess into which the tip of the male member is pushed. The lower base can include a pair of lower base bodies divided into two halves in the extension direction of the road. In this case, multiple reinforcing bars are arranged inside each lower base body, and concrete is poured in a grid pattern, with the female member of the one-pass joint attached via a fixed reinforcing bar in the space surrounded by the concrete poured in a grid pattern. The upper base can also include a pair of upper base bodies divided into two halves in the extension direction of the road. In this case, multiple reinforcing bars are arranged inside each upper base body, and concrete is poured, with the male member of the one-pass joint attached via a fixed reinforcing bar in the upper base at a position corresponding to the female member installed on the lower base. In a bridge expansion device with this structure, the upper base is positioned above the lower base, and the male member is pushed into the recess provided in the female member of the one-pass joint to connect and fix the lower and upper bases. Meanwhile, the connection between the lower and upper bases is released by removing the tip of the male member from the recess provided in the female member of the one-pass joint. [Effects of the Invention]

[0014] In the bridge expansion device using precast concrete members and its construction method according to the present invention, the expansion device main body is installed on a road structure such as a deck slab using a precast concrete base divided into upper and lower halves. When replacing the expansion device main body, the upper base and the expansion device main body installed above it are removed, while the lower base remains fixed to the road structure such as a deck slab. The lower and upper bases can be attached and detached using a one-pass joint.

[0015] Therefore, if a bridge expansion joint using the precast concrete member according to the present invention is installed, chipping work will be unnecessary or only a small part of it will be required in repair work on the expansion joint body, which will not only reduce noise generation but also minimize the impact on road structures such as decks. Furthermore, new installation work and repair and replacement work for bridge expansion joints will become easier, which may reduce construction costs and improve construction quality.

[0016] In this way, the bridge expansion device and its construction method using Pca members of the present invention make it possible to improve productivity and ensure quality at construction sites when installing and repairing bridge expansion devices. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic diagram of a lower base used in a bridge expansion device according to an embodiment of the present invention. FIG. [Figure 2] 1 is a schematic diagram of an upper base used in a bridge expansion device according to an embodiment of the present invention. FIG. [Figure 3] 1 is a schematic diagram of a one-pass type joint used in a bridge expansion device according to an embodiment of the present invention. [Figure 4] 1 is a schematic diagram showing a procedure for installing a bridge expansion device according to an embodiment of the present invention. FIG. [Figure 5] 1 is a schematic diagram showing a procedure for installing a bridge expansion device according to an embodiment of the present invention. FIG. [Figure 6] 1 is a schematic diagram showing a procedure for installing a bridge expansion device according to an embodiment of the present invention. FIG. [Figure 7] 1 is a schematic diagram showing a procedure for installing a bridge expansion device according to an embodiment of the present invention. FIG. [Figure 8] 1 is a schematic diagram showing a procedure for installing a bridge expansion device according to an embodiment of the present invention. FIG. [Figure 9] 1 is a schematic diagram showing a procedure for installing a bridge expansion device according to an embodiment of the present invention. FIG. [Figure 10] 1 is a schematic diagram showing a procedure for installing a bridge expansion device according to an embodiment of the present invention. FIG. [Figure 11] 1 is a schematic diagram showing a procedure for installing a bridge expansion device according to an embodiment of the present invention. FIG. [Figure 12] FIG. 2 is a schematic diagram showing a waterproofing mechanism installed on a lower base of the bridge expansion device according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, a bridge expansion device and its construction method according to an embodiment of the present invention will be described with reference to the drawings. Figures 1 to 12 explain a bridge expansion device and its construction method according to an embodiment of the present invention, with Figure 1 being a schematic diagram of the lower base (a: plan view, b: longitudinal section, c: side view), Figure 2 being a schematic diagram of the upper base (a: plan view, b: longitudinal section, c: side view), Figure 3 being a schematic diagram of a one-pass joint, Figures 4 to 11 being schematic diagrams showing the installation procedure for the bridge expansion device, and Figure 12 being a schematic diagram showing the waterproofing mechanism of the lower base (a: perspective view, b: enlarged longitudinal section).

[0019] <Outline of bridge expansion devices and their construction methods> In the construction of bridge expansion joints, rather than installing the expansion joint body directly on a deck or road structure using conventional construction methods, the present invention has a structure in which a base for installing the expansion joint body (hereinafter referred to as a PCa base) is fixed to a structure such as a deck slab, and then the expansion joint body is installed on the PCa base. This construction method is particularly useful for replacing expansion joint bodies, but can also be applied when installing new expansion joint bodies.

[0020] The PCa base is made up of a lower base and an upper base, and has a separate structure (divided into upper and lower halves) so that when replacing the expansion joint body, it can be easily, quickly, and reliably removed even by non-skilled workers, while reducing noise.

[0021] The upper pedestal is detachably attached to the lower pedestal. The mechanism for attaching and detaching the lower and upper pedestals uses a one-pass joint, which is used in shield tunnel segments, to reduce noise and allow for easy attachment and detachment when replacing the expansion joint body. Furthermore, by manufacturing the upper pedestal and the expansion joint body as an integrated structure in the factory, construction can be carried out even more easily and quickly, and construction costs can be reduced.

[0022] <Expansion device body> The expansion and contraction device main body 10 is a device for following the expansion and contraction of the bridge girder so as not to restrain the temperature expansion and contraction of the bridge girder or the contraction due to creep in the bridge and not to impair the running performance of automobiles or the like passing through the bridge. The expansion and contraction device main body 10 in the present embodiment is a device having a general structure that has been used conventionally. As shown in FIG. 4, it is divided into two parts in the extension direction of the road (the traveling direction of the vehicle) and includes a pair of base parts 11 installed at intervals. The main body part 12 of the expansion and contraction device main body 10 is installed so as to span between the pair of base parts 11. Further, the lower end parts (anchor bars) of the reinforcing bars 63 arranged inside each base part 11 are embedded in the floor slab 20, so that each base part 11 is fixed to the floor slab 20. In addition, a waterproof mechanism 30 is provided between the pair of base parts 11. Note that the structure of the expansion and contraction device main body 10 is not limited to the structure shown in FIG. 1, and any structure may be used as long as it can be attached to the upper pedestal 70.

[0023] <PCa pedestal> The present invention is characterized by a PCa (Precast Concrete) pedestal for installing the expansion and contraction device main body 10. The PCa pedestal 50 of the present embodiment is a member prefabricated in a factory in advance and includes a lower pedestal 60 and an upper pedestal 70 detachably attached to the lower pedestal 60. In the present embodiment, a one-pass type joint 40 is used for attaching and detaching the lower pedestal 60 and the upper pedestal 70. As will be described in detail later, the lower pedestal 60 is a member having a function of fixing to the floor slab 20 and may be integrated with the floor slab 20. Further, the upper pedestal 70 is a member for attaching the expansion and contraction device main body 10 to the upper part and being detachably attached to the lower pedestal 60, and may be integrated with the expansion and contraction device main body 10.

[0024] <Lower pedestal> As shown in Figure 1, the lower base 60 comprises a pair of lower base bodies 61 divided into two in the extension direction of the road (the direction of vehicle travel). Each lower base body 61 has end steel plates 62 on the opposing sides, and has multiple reinforcing bars 63 arranged inside, with concrete 64 poured in a lattice pattern. In addition, the female member 41 of the one-pass joint 40 is attached via fixed reinforcing bars 65 to the space surrounded by the concrete 64 poured in a lattice pattern.

[0025] In the example shown in FIG. 1 , the installation position of the female member 41 is determined when the lower pedestal 60 is manufactured, but the structure may also be such that the installation position of the female member 41 can be set arbitrarily within a predetermined range. That is, when the lower pedestal 60 is manufactured in a factory, it is preferable that the installation position of the female member 41 is not fixed, but that the female member 41 can be installed at an appropriate position within a predetermined range at the site where the lower pedestal 60 is to be installed. This allows the female member 41 to be installed in accordance with the reinforcement state of the deck slab 20, etc., and the lower pedestal 60 can be easily installed without damaging the reinforcing bars (not shown) of the deck slab 20, etc. In such a structure, it is also necessary to be able to set the installation position of the male member 42 in the upper pedestal 70 in accordance with the installation position of the female member 41.

[0026] The lower pedestal 60 is fixed to the deck slab 20 using a plurality of anchors 67. For example, after the lower pedestal 60 is installed on the deck slab 20, the anchors 67 are welded to the reinforcing bars 63 of the lower pedestal 60. Then, concrete is poured into the gaps in the lower pedestal 60, or mortar (non-shrinkage type) is filled into the gaps in the lower pedestal 60, thereby fixing the lower pedestal 60 to the deck slab 20 (see FIGS. 6 and 7). Also, in this embodiment, the lower pedestal 60 is structured to be fixed to the deck slab 20, but the lower pedestal 60 may be precast integrally with the deck slab 20. In other words, the precast deck slab 20 and the lower pedestal 60 precast integrally with the deck slab 20 can function as the lower pedestal 60 defined in the present invention.

[0027] <Waterproof mechanism> As shown in Fig. 12, it is preferable to install a waterproofing mechanism 30 on the lower pedestal 60 to provide waterproofing between the pair of lower pedestal bodies 61. A water-stopping material 32 that spans between the pair of lower pedestal bodies 61 has a fixed portion 36 and a free portion 37 with a substantially U-shaped cross section. This water-stopping material 32 can provide waterproofing between the pair of lower pedestal bodies 61.

[0028] The lower base 60a on which the waterproofing mechanism 30 is attached has a structure similar to that of the lower base 60 shown in Fig. 6, and similar members will be denoted with the same reference numerals in the following description. The lower bases 60a on which the waterproofing mechanism 30 is attached have cutouts 66 formed in the upper portions of the opposing sides, and end steel plates 62a with a generally L-shaped cross section are attached from the bottom of the cutouts 66 along the side surfaces of the lower base main body 61. Nuts (cap nuts) 31 are embedded in the undersides of the end steel plates 62a attached to the cutouts 66.

[0029] Then, the fixing portion 36, which is one end of the water-stopping material 32, is placed on the upper surface of one end steel plate 62a, the support plate 33 is faced into the cutout portion 66 from above the fixing portion 36, bolts 35 are inserted from above the bolt insertion holes 34 formed in the support plate 33, and the tips of the bolts 35 are screwed into nuts (cap nuts) 31, thereby fixing the water-stopping material 32 (fixing portion 36) to one lower pedestal body 61. A plurality of bolt insertion holes 34 are formed along the length of the support plate 33, and a plurality of nuts (cap nuts) 31 are embedded in the lower pedestal body 61 so as to face the bolt insertion holes 34.

[0030] Similarly, the fixed part 36, which is the other end of the waterstop material 32, is placed on the upper surface of the other end steel plate 62a, the support plate 33 is faced into the cutout part 66 from above the fixed part 36, a bolt 35 is inserted from above the bolt insertion hole 34 provided in the support plate 33, and the tip of the bolt 35 is screwed into the nut (cap nut) 31, thereby fixing the waterstop material 32 (fixed part 36) to the other lower base main body 61. In addition, because the waterstop material 32 has a free part 37, it follows the movement of the expansion device main body 10 and does not restrict the contraction of the bridge girder due to temperature expansion and contraction or creep.

[0031] The water stop material 32 is made of rubber, stainless steel, etc., and is installed with consideration given to drainage treatment, terminal treatment, etc. The water stop material 32 is a component that secures the lower pedestal 60 to the deck slab 20 and is left on the deck slab 20 when replacing the expansion device main body 10, but there is a risk of it deteriorating over time. Therefore, when replacing the expansion device main body 10 and the upper pedestal 70, it is preferable to replace the waterproof mechanism 30 made of the water stop material 32, etc., with the pair of lower pedestal bodies 61 secured to the deck slab 20.

[0032] <Upper pedestal> As shown in Figure 2, the upper pedestal 70 has a pair of upper pedestal bodies 71 that are divided into two halves in the extension direction of the road (the direction of vehicle travel). Each upper pedestal body 71 has a plurality of reinforcing bars 72 arranged inside and is filled with concrete 73. In addition, the male member 42 of the one-pass joint 40 is attached via a fixed reinforcing bar 74 at a position corresponding to the female member 41 installed on the lower pedestal 60.

[0033] 2, the installation position of the male member 42 is determined when the upper pedestal 70 is manufactured, but the structure may also be such that the installation position of the male member 42 can be set arbitrarily within a predetermined range. As described above, when the lower pedestal 60 is manufactured in a factory, the installation position of the female member 41 is not fixed, but rather, it can be set so that the female member 41 can be installed at an appropriate position within a predetermined range at the site where the PCa pedestal 50 is installed. In such a structure, it is necessary to be able to set the installation position of the male member 42 in the upper pedestal 70 in accordance with the installation position of the female member 41.

[0034] Furthermore, in this embodiment, the lower pedestal 60 and the upper pedestal 70 are integrated together, and then the extension device main body 10 is attached to the top of the upper pedestal 70, but the upper pedestal 70 may be PCa-processed together with the extension device main body 10. In other words, the PCa-processed upper pedestal 70 and the PCa-processed extension device main body 10 integrated with the upper pedestal 70 can function as the upper pedestal 70 defined in the present invention.

[0035] <One-pass type fitting> The one-pass joint 40 is an example of a mechanism for detachably connecting the lower base 60 and the upper base 70. This one-pass joint 40 is a joint for detachably connecting the lower base 60 and the upper base 70, and is also called a quick joint. As shown in Figure 3 and Figures 6 to 11, this one-pass joint 40 is made up of a female member 41 and a male member 42. The female member 41 has a recess 43 into which the tip end (fixing bolt 44) of the male member 42 is pushed.

[0036] A female thread portion 46 is provided within the recess 43 of the female member 41, into which a male thread portion 45 provided on the outer peripheral surface of the fixing bolt 44 constituting the male member 42 is screwed. In addition, although not shown, a fastening member (not shown) is provided which is located closer to the open end of the recess 43 than the female thread portion 46, is movable in the axial direction within the recess 43, allows the male thread portion 45 to be pushed in, and comes into close contact with the male thread portion 45 after it has been pushed in, thereby preventing the male thread portion 45 from being pulled out of the recess 43.

[0037] On the other hand, the male member 42 has a fixing bolt 44 to be inserted into the recess 43 of the female member 41, and an anchor portion 47 for fixing the male member 42 to the upper pedestal 70. In this embodiment, the anchor portion 47 has a sleeve tube 47a through which the fixing bolt 44 is inserted, and a flange portion 47b that protrudes from the lower end of the sleeve tube 47a toward the outer periphery. The tip of the fixing bolt 44 is provided with a male thread portion 45 that is screwed into a female thread portion 46 provided in the recess 43 of the female member 41. The male thread portion 45 may be provided over the entire length of the fixing bolt 44, in which case a female thread portion (not shown) may be provided on the inner wall surface of the sleeve tube 47a.

[0038] In this embodiment, the female member 41 is attached to the lower pedestal 60, and the male member 42 is attached to the upper pedestal 70. Then, with the upper pedestal 70 facing above the lower pedestal 60, the tip of the fixing bolt 44 of the male member 42 is pressed into the fastening member provided in the recess 43 of the female member 41, and further, the male threaded portion 45 of the fixing bolt 44 is screwed into the female threaded portion 46 provided in the recess 43 of the female member 41, thereby connecting and fixing the lower pedestal 60 and the upper pedestal 70 using the one-pass joint 40.

[0039] In addition, by turning the fixing bolt 44 of the male member 42 in the direction of disconnection, the fixing bolt 44 can be removed from the female thread portion 46 provided in the recess 43 of the female member 41 and the fastening member (not shown), and the connection between the lower base 60 and the upper base 70 by the one-pass type joint 40 can be released.

[0040] In this embodiment, a one-pass joint 40 is used to detachably fasten the lower base 60 and the upper base 70. The structure of the one-pass joint 40 is not limited to that described above, and any structure may be used as long as it can fix the upper base 70 to the lower base 60 to form an integrated unit, and the lower base 60 and the upper base 70 can be released from the fixation to separate the two. Furthermore, the mechanism for detachably fastening the lower base 60 and the upper base 70 is not limited to the one-pass joint 40, and any mechanism may be used as long as it can fix the upper base 70 to the lower base 60 to form an integrated unit, and the lower base 60 and the upper base 70 can be released from the fixation to separate the two.

[0041] <Construction procedure for bridge expansion joints> A construction method for a bridge expansion device using a precast concrete member according to an embodiment of the present invention will be described with reference to Figures 4 to 10. Figure 4 is an explanatory diagram showing the state in which an existing bridge expansion device has been installed, Figure 5 is an explanatory diagram showing the state in which the existing bridge expansion device has been removed, Figure 6 is an explanatory diagram showing the state in which the lower base 60 has been installed, Figure 7 is an explanatory diagram showing the state in which the filling concrete pouring process has been carried out after the installation of the lower base 60, Figure 8 is an explanatory diagram showing the process of installing the upper base 70, Figures 9 and 10 are explanatory diagrams showing the process of installing a new expansion device main body 10, and Figure 11 is an explanatory diagram showing the process of removing the expansion device main body 10 and the upper base 70. Note that in the following description, the PCa base 50 is fixed to the deck slab 20, but depending on the bridge structure, the PCa base 50 may be fixed to another road structure instead of the deck slab 20.

[0042] The construction procedure for a bridge expansion device explained below also covers the case where an existing bridge expansion device exists. In this regard, the construction method for a bridge expansion device of the present invention aims to prevent unnecessary damage to the existing deck slab 20 and substructures, etc., caused by chipping work using a breaker or the like when removing an existing bridge expansion device, and to reduce noise generated during the removal work of the bridge expansion device.

[0043] However, if an existing bridge expansion device exists, it is necessary to remove this bridge expansion device before installing a bridge expansion device using a Pca member according to an embodiment of the present invention. After installing a bridge expansion device using a Pca member according to an embodiment of the present invention, the above-mentioned objective of the present invention can be achieved. Therefore, the case where an existing bridge expansion device exists is also described, and the process of removing this existing bridge expansion device is a necessary process for subsequently replacing the bridge expansion device (tension device main body 10), so it does not contradict the objective of the present invention.

[0044] <Construction procedure / When there is an existing bridge expansion joint> As shown in Figure 4, if there is an existing bridge expansion device, it must be removed. Therefore, the existing bridge expansion device is removed by chipping using a breaker or similar tool. The chipping work is done to ensure space for installing the PCa base 50 and the new expansion device body 10. Once the chipping work is complete, the lower parts of the anchor bars (reinforcing bars 13) used to secure the existing bridge expansion device to the deck slab 20 remain on the deck slab 20, as shown in Figure 5.

[0045] In this state, as shown in Fig. 6, a lower base 60 is installed below the space created by the chipping work, and the lower base 60 is connected to the deck slab 20 using anchors 67. Next, as shown in Fig. 7, a filler pouring (filling) process is carried out, and as shown in Fig. 8, an upper base 70 is placed above the lower base 60, and the lower base 60 and the upper base 70 are integrated and fixed together using a one-pass joint 40 (a female member 41 provided on the lower base 60 and a male member 42 provided on the upper base 70). In Figs. 7 and 8, reference numeral 68 denotes filler material (concrete or mortar).

[0046] Thereafter, as shown in Fig. 9, the new expansion device body 10 is placed facing the upper pedestal 70 from above, and the new expansion device body 10 is installed on the upper pedestal 70. Then, as shown in Fig. 10, post-cast concrete 80 is poured into the space in which the upper pedestal 70 and the new expansion device body 10 are installed, thereby completing the installation of the new expansion device body 10.

[0047] <Construction procedure / When PCa base (lower base) is installed> 10, when a bridge expansion device using a Pca member according to an embodiment of the present invention has already been installed, the male member 42 of the one-pass joint 40 provided on the upper pedestal 70 and the female member 41 of the one-pass joint 40 provided on the lower pedestal 60 are released from the connection as shown in FIG. 11. By turning the fixing bolt 44 of the male member 42 in the direction of release of connection, the fixing bolt 44 is removed from the female threaded portion 46 and fastening portion provided in the recess 43 of the female member 41, and the connection between the lower pedestal 60 and the upper pedestal 70 by the one-pass joint 40 can be released. Then, when the integrated expansion device main body 10 and upper pedestal 70 are removed, the lower pedestal 60 fixed to the deck slab 20 is left behind, as shown in FIG.

[0048] From this state, the lower pedestal 60 and the upper pedestal 70 are fixed together using a one-pass joint 40, as shown in Fig. 8. Then, as shown in Fig. 9, the new expansion device body 10 is placed on the upper pedestal 70, facing it from above. Furthermore, as shown in Fig. 10, post-cast concrete 80 is poured into the space in which the upper pedestal 70 and the new expansion device body 10 are installed, thereby completing the installation of the new expansion device body 10.

[0049] <Construction procedure / When constructing a new PCa base> When a new bridge expansion device using a precast concrete member according to an embodiment of the present invention is installed during bridge construction, a space is secured for installing the PCa base 50 and the expansion device main body 10, as shown in Fig. 5. Note that Figs. 5 to 11 show a state in which the existing bridge expansion device has been removed, and therefore anchor bars (reinforcing bars 13) are present, but when a new PCa base 50 is installed during bridge construction, anchor bars (reinforcing bars 13) are not present.

[0050] Next, in the same manner as when an existing bridge expansion device exists, the lower pedestal 60 is installed as shown in FIG. 6 and fixed to the deck slab 20 using anchors 67, and then a concrete pouring (filling) process is carried out as shown in FIG. 7. As shown in FIG. 8, the upper pedestal 70 is placed above the lower pedestal 60, and the lower pedestal 60 and the upper pedestal 70 are fixed together using a one-pass joint 40 (female member 41 provided on the lower pedestal 60 and male member 42 provided on the upper pedestal 70). When a bridge expansion device according to this embodiment is newly installed, in addition to using the anchors 67 shown in the drawings, pre-installed anchors (slab-embedded anchors) such as anchor reinforcement may be embedded in the deck slab 20. Furthermore, an anchor portion (not shown) may be integrally provided at the bottom of the female member 41 of the one-pass joint 40, and the anchor portion may serve as a supplementary element for the anchor 67.

[0051] Thereafter, as shown in FIG. 9, the new expansion device body 10 is placed on the upper pedestal 70 with the new expansion device body 10 facing from above, and as shown in FIG. 10, post-cast concrete 80 is poured into the space where the upper pedestal 70 and the new expansion device body 10 are placed, thereby completing the installation of the new expansion device body 10.

[0052] <Other embodiments> The above explanation of the construction procedure has been given for the case where a precast concrete base 50 consisting of a lower base 60 and an upper base 70 shown in Figures 1 and 2 is used. As mentioned above, the member that detachably connects the lower base 60 and the upper base 70 is not limited to the one-pass joint 40. Furthermore, when a one-pass joint 40 is used, the installation positions of the female member 41 and the male member 42 can be adjusted. Furthermore, a waterproofing mechanism 30 can also be provided on the lower base 60. Furthermore, the deck slab 20 and the lower base 60 may be manufactured as a single unit by precast concrete, or the upper base 70 and the expansion device main body 10 may be manufactured as a single unit by precast concrete.

[0053] When a PCa base 50 having such a structure is used, the construction procedure can be modified as appropriate in accordance with the construction procedure described above to attach or remove a bridge expansion device using a PCa member to a road structure (deck slab 20). [Explanation of symbols]

[0054] 10 Expansion device body 11 Foundation 12 Main body 13 Reinforcement of expansion joint body 20 Floor slab 30 Waterproof mechanism 31 Nut 32 Water-stopping material 33 Bearing plate 34 Bolt insertion hole 35 volts 36 Fixed part 37 Free section 40 One-pass type joint 41 Female member 42 Male member 43 Recess 44 Fixing bolt 45 Male thread 46 Female thread 47 Anchor part of male member 47a sheath tube 47b Flange part 50 PCa pedestal 60 Lower pedestal 60a Lower base for attaching waterproof mechanism 61 Lower base body 62 End steel plate 62a End steel plate for attaching waterproofing mechanism 63 Reinforcement of lower base 64 Concrete 65 Fixed rebar 66 Notch 67 Anchor 68 Filling material 70 Upper pedestal 71 Upper base body 72 Reinforcement of upper base 73 Concrete 74 Fixed rebar 80 Post-cast concrete

Claims

1. An expansion device for bridges in which an expansion device body is attached to a road structure via a PCa base, The PCa base comprises a lower base that is fixed to a road structure, and an upper base that is formed separately from the lower base, is detachably attached to an upper portion of the lower base, and on which the expansion device main body is placed, When replacing the expansion device body, the lower base is fixed to the road structure, The upper base is detached from the lower base when replacing the telescopic device body. A bridge expansion device using a Pca member.

2. a one-pass joint for attaching and detaching the upper base to and from the lower base; The one-pass type joint comprises a female member and a male member, The female member has a recess into which the tip of the male member is pushed. A bridge expansion and contraction device using the Pca member according to claim 1.

3. The lower base comprises a pair of lower base bodies divided into two in the extension direction of the road, Inside each lower base body, multiple reinforcing bars are arranged and concrete is poured in a grid pattern. The female member of the one-pass joint is attached via a fixed reinforcing bar to a space surrounded by concrete poured in a grid pattern, The upper base includes a pair of upper base bodies divided into two in the extension direction of the road, Inside each upper base body, multiple reinforcing bars are arranged and concrete is poured. The male member of the one-pass joint is attached to the upper base at a position corresponding to the female member installed on the lower base via a fixing reinforcing bar. A bridge expansion and contraction device using the Pca member according to claim 2.

4. A construction method for a bridge expansion device in which an expansion device main body is attached to a road structure via a PCa base, The PCa base comprises a lower base that is fixed to the road structure, and an upper base that is formed separately from the lower base, is detachably attached to the upper part of the lower base, and on which the expansion device main body is placed, When attaching the extension device main body to a road structure, the lower base is fixed to the road structure, the upper base is attached to the top of the lower base, and the extension device main body is attached to the top of the upper base, When replacing the extension device body, the extension device body is replaced by removing the upper base and the extension device body attached to the upper part of the lower base while leaving the lower base fixed to the road structure. A construction method for a bridge expansion device using a Pca member.

5. A one-pass joint is used to attach and detach the upper base to and from the lower base, The one-pass type joint comprises a female member and a male member, and the female member has a recess into which the tip end of the male member is pushed. A method for constructing a bridge expansion device using the Pca member according to claim 4.

6. The lower base comprises a pair of lower base bodies divided into two in the extension direction of the road, Inside each lower base body, multiple reinforcing bars are arranged and concrete is poured in a grid pattern. The female member of the one-pass joint is attached via a fixed reinforcing bar to a space surrounded by concrete poured in a grid pattern, The upper base includes a pair of upper base bodies divided into two in the extension direction of the road, Inside each upper base body, multiple reinforcing bars are arranged and concrete is poured. The male member of the one-pass joint is attached to the upper base at a position corresponding to the female member installed on the lower base via a fixed reinforcing bar, The upper seat is positioned above the lower seat, and the male member is pushed into a recess provided in the female member of the one-pass joint, thereby connecting and fixing the lower seat and the upper seat; the connection between the lower seat and the upper seat is released by removing the tip end of the male member from the recess provided in the female member of the one-pass joint; A method for constructing a bridge expansion device using the Pca member according to claim 5.

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