BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an earthquake-resistant flat expansion joint used in bridges or elevated roads, and more particularly, to an earthquake-resistant flat expansion joint using a hinge, which is capable of improving the structure of a main body of the expansion joint to be movable in X, Y and Z directions, i.e., three axial directions upon occurrence of earthquakes to prevent damage to structure due to the expansion joint connected to the structures when slabs connected to the expansion joints, girders and breast walls of abutments are moved by the earthquakes, avoiding traffic disturbance even through the earthquake occurs, and further preventing secondary damage to a lower structure due to traffic jam caused by traffic control and delayed exchange of a damaged rubber seal member by improving a rubber seal for collecting rainwater and foreign substances in a structure exchangeable independently from the expansion joint.
2. Description of Related Art
Generally, a relatively long bridge having a plurality of piers has a plurality of deck slabs divided in a longitudinal direction thereof in order to deal with expansion and shrinkage of the bridge caused by temperature variation. Expansion joints are installed between the deck slabs.
FIG. 1 is a view showing a structure of a conventional expansion joint for a bridge.
Referring to FIG. 1, the conventional expansion joint for a bridge includes upper cover plates 101a and 101b installed at opposite ends of the deck slabs to be coupled to each other and expandable according to temperature variation, anchor bolts 102 for fastening the upper cover plates 101a and 101b to after-cured concretes 105, reinforcement iron rods 103 for increasing a fastening force between the anchor bolts 102 and the after-cured concretes 105 and reinforcing strength of the after-cured concretes 105, and a rainwater and foreign substances collecting rubber seal 104 fixed to the after-cured concretes 105 at both ends thereof. Designated by reference numeral 106 are reinforcing rods disposed in the deck slabs of the bridge.
Although the conventional expansion joint for a bridge having the structure as above can be moved in a vehicle moving direction within an expandable range when an earthquake occurs, it is impossible for the expansion joint to move in a lateral direction, i.e., in a direction perpendicular to the vehicle moving direction. In addition, since the expansion joints are not allowed to be moved in a longitudinal direction, when breast walls of abutments vertically move upon occurrence of the earthquake, the slabs, girders, and other structures installed at the bridge, to which the expansion joints are coupled, may be damaged due to the earthquake, so that the deck slabs are separated form the bridge.
Further, the rubber seal 104 is coupled to a concrete slab by the anchor bolts 102 before installation of the upper cover plates 101a and 101b. Then, the upper cover plates 101a and 101b are installed and nuts are fastened to the anchor bolts 102, thereby completing installation of the expansion joint. Therefore, when the rubber seal 104 is damaged, the upper cover plates 101a and 101b have to be opened to exchange the damaged rubber seal 104 after traffic control. In addition, this damaged rubber seal may bring about rainwater leakage, thereby causing additional damage to a lower structure.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above drawbacks, and it is, therefore, an object of the present invention to provide an earthquake-resistant flat expansion joint using a hinge, which is capable of improving the structure of a main body of the expansion joint to be movable in X, Y and Z directions, i.e., three axial directions upon occurrence of earthquakes to prevent damage to structure due to the expansion joint connected to the structures when slabs connected to the expansion joints, girders and breast walls of abutments are moved by the earthquakes, avoiding traffic disturbance even through the earthquake occurs, and further enabling to use the expansion joint as it is, without additionally installing a new expansion joint when a deck slab is recovered.
Another object of the present invention is to provide an earthquake-resistant flat expansion joint using a hinge, which is capable of preventing secondary damage to a lower structure due to traffic jam caused by traffic control and delayed exchange of a damaged rubber seal by improving a rubber seal for collecting rainwater and foreign substances in a structure exchangeable independently from the expansion joint.
According to the present invention for achieving the above object, there is provided an earthquake-resistant flat expansion joint using a hinge comprising: an expansion joint main body disposed between opposite ends of deck slabs of a bridge or an elevated road, hinged to one side of the deck slab at its one end to enable behavior in X, Y and Z-axis directions, and expanded or shrunk depending on temperature variation and vibrations due to earthquakes to be moved in the X, Y and Z-axis directions; an expansion/shrinkage member connected to one end of the expansion joint main body to accommodate the behavior in X, Y and Z-axis directions due to expansion and shrinkage of the expansion joint main body caused by temperature variation and occurrence of the earthquakes; a hinge shaft support member installed at one end of the deck slab to support a lower part and side parts of a hinge shaft part of the expansion joint main body; an expansion joint support member installed at one end of the other deck slab to support lower parts of an expansion part of the expansion joint main body and the expansion/shrinkage member; anchor bolts for fixing the hinge shaft support member and the expansion joint support member to the opposite deck slabs; and a rubber seal disposed under the expansion joint main body and detachably installed at a space between both opposite ends of the deck slabs to collect rainwater and foreign substances.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing a structure of a conventional expansion joint for a bridge.
FIG. 2 is a view illustrating a structure of an earthquake-resistant flat expansion joint using a hinge in a normal state according to a first exemplary embodiment of the present invention.
FIG. 3 is a view showing expansion/shrinkage behavior in an X-axis direction of the earthquake-resistant flat expansion joint using a hinge upon occurrence of earthquakes.
FIG. 3A is a view of the earthquake-resistant flat expansion joint using a hinge according to the present invention, showing a reason that a hinge shaft of a main body of the expansion joint should be oriented in an entrance direction of vehicles.
FIG. 4 is a perspective view illustrating a structure of an expansion/shrinkage member of the earthquake-resistant flat expansion joint using a hinge according to the present invention.
FIG. 5 is a front view showing an assembled state of a rubber seal and its fixing devices in the earthquake-resistant flat expansion joint using a hinge according to the present invention.
FIG. 6 is an exploded perspective view showing the rubber seal, and its fixing devices of the earthquake-resistant flat expansion joint using a hinge according to the present invention.
FIGS. 6A to 6C are views showing various installation examples of the rubber seal in the earthquake-resistant flat expansion joint using a hinge according to the present invention.
FIG. 7 is a view showing a case in which a rubber seal and a guide rail of the earthquake-resistant flat expansion joint using a hinge according to the present invention are installed in a sloped manner.
FIG. 8 is a view showing a case in which the rubber seal of the earthquake-resistant flat expansion joint using a hinge according to the present invention are designed and manufactured to be sloped, and installed at a horizontal guide rail.
FIGS. 9A to 9C are views showing earthquake-resistant flat expansion joints using a hinge according to second, third and fourth embodiments of the present invention.
FIG. 10 is a view showing a mechanism that the earthquake-resistant flat expansion joint using a hinge according to the present invention deals with vertical behavior in a Y-axis direction upon occurrence of earthquakes.
FIG. 11 is a view showing a state that a main body of the expansion joint and an expansion/shrinkage member of the earthquake-resistant flat expansion joint using a hinge according to the present invention are separated from each other to remove contaminants accumulated in the rubber seal.
DESCRIPTION OF SPECIFIC EMBODIMENTS
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIGS. 2 and 3 are views showing an earthquake-resistant flat expansion joint using a hinge according to a first embodiment of the present invention. That is, FIG. 2 illustrates a normal state of the expansion joint, and FIG. 3 illustrates behavior in an X-axis direction of the earthquake-resistant flat expansion joint using a hinge upon occurrence of earthquakes.
Referring to FIGS. 2 and 3, the earthquake-resistant flat expansion joint using a hinge according to a first embodiment of the present invention includes an expansion joint main body 210, an expansion/shrinkage member 220, a hinge shaft support member 240, anchor bolts 250, and a rubber seal 260.
The expansion joint main body 210 is disposed between opposite deck slabs 205a and 205b of a bridge or an elevated road and hinged to one deck slab 205a at its one end to allow behavior in X, Y and Z-axis directions, i.e., three-axial directions. The expansion joint main body can be moved in the X, Y and Z-axis directions, i.e., three-axial directions depending on expansion and shrinkage of the deck slabs due to temperature variation and occurrence of earthquakes. The expansion joint main body 210 includes a cylindrical hinge shaft part 210s fixed to a hinge shaft, and a flat plate part 210p integrally formed with the hinge shaft part 210s. In addition, step grooves 210h for inserting connection members and fastening the connection members by bolts are formed at side surfaces of the plate parts 210p to connect adjacent expansion joint main bodies 210 such that the expansion joints are integrally moved. A rubber piece member or an iron piece member 270 as the connection member is inserted into the grooves 210h with gaps therebetween and fastened to the main bodies by bolts, thereby connecting several adjacent expansion joint main bodies 210. Each of the expansion joint main bodies 210 is formed of steel.
Meanwhile, in installation of the expansion joint main body 210 having such a structure, as shown in FIG. 3A, a worker make it a rule to install the hinge shaft part 210s of the expansion joint main body 210 in an entrance direction of vehicles. The reason is as follows. That is, when earthquakes occur, the plate part 210p of the expansion joint main body 210 is raised or lowered about the hinge shaft 210s. At this time, if the end of the plate part 210p is raised toward the entrance direction of the vehicles, wheels or bottom of the entered vehicle collide with the end of the plate part 210p to make it difficult the vehicle entry to the bridge, or cause traffic accidents.
The expansion/shrinkage member 220 is connected to the end of the plate part 210p of the expansion joint main body 210 to accommodate behavior in X, Y and Z-axis directions caused by expansion/shrinkage due to temperature variation of the expansion joint main body 210 and earthquakes. As shown in FIG. 4, the expansion/shrinkage member 220 is formed of a corrugated structure having a plurality of hollows 220h for accommodating behavior of the plate part 210p caused by the expansion/shrinkage and the earthquakes. In particular, rise-prevention wrinkles 220w are formed at a lower surface of the corrugated structure and disposed between the hollows 220h to prevent the expansion/shrinkage member 220 from rising when the plate part 210p is moved by the earthquake, and so on. The expansion/shrinkage member 220 is formed of a reinforced rubber material. In addition, the expansion/shrinkage member 220 is fixed to each of the end of the plate part 210p of the expansion joint main body 210 and the expansion joint support member 240 (to be described later) using fixing members 300 (see FIG. 11).
Here, the fixing members 300 connect and fix the expansion/shrinkage member 220 to each of the end of the plate part 210p of the expansion joint main body 210 and a key part of the expansion joint support member 240. Each of the fixing members 300 includes a fixing piece 301 having a groove engaged with one of protrusions 220t formed at both ends of the expansion/shrinkage member 220 and a through-hole through which a bolt passes, a bolt 302 for fastening and fixing the fixing piece 301 to each of the plate part 210p of the expansion joint main body 210 and the key part of the expansion joint support member 240, and a bushing 303 having a female threaded part and fixing the bolt 302 to each of the plate part 210p of the expansion joint main body 210 and the key part of the expansion joint support member 240. Preferably, the bushing 303 may be formed of stainless steel or may be plated with a metal material to prevent generation of corrosion.
After fastening the bolt 302 in a state that the fixing piece 301 of the fixing member 300 is inserted into one of the protrusions 220t (see FIG. 4) formed at both ends of the expansion/shrinkage member 220, the bolt 302 is fastened to the bushing 303 installed at the end of the plate 210p and the key part of the expansion joint support member 240 to securely fix the expansion/shrinkage member 220 to each of the end of the plate 210p and the key part of the expansion joint support member 240. Now, a method of exchanging the expansion/shrinkage member 220 in relation to the fixing member 300 as mentioned above will be described.
When the expansion/shrinkage member 220 is deteriorated with the passage of time, ride comfort of the vehicles is also decreased. In this case, the method of exchanging the expansion/shrinkage member 220 is as follows.
First, the bolts 302 fastened to the fixing members 300 are released to separate the fixing pieces 301 from both ends of the expansion/shrinkage member 220, respectively. Then, the damaged expansion/shrinkage member 220 is removed and replaced with a new one. Next, the fixing pieces 301 are fastened to both ends of the expansion/shrinkage member 220, respectively, such that the grooves of the fixing pieces 301 are meshed with the protrusions 220t of both ends of the new expansion/shrinkage member 220, and then, the bolts 302 are fastened again. Thereafter, in order to prevent corrosion of the bolts due to rainwater, a waterproof treatment is performed around the bolts 302 by sealing.
Meanwhile, the hinge shaft support member 230 is installed at one end of the deck slab 205a to support a lower part and side parts of the hinge shaft part 210s of the expansion joint main body 210 in a surrounding fashion. The hinge shaft support member 230 is configured to have a cylindrical inner periphery corresponding to a cylindrical outer periphery of the hinge shaft part 210s such that the hinge shaft part 210s can be freely and vertically pivoted therein. The hinge shaft support part 230 is formed of steel.
The expansion joint support member 240 is installed at one end of the other deck slab 250b to support lower parts of the plate part 210p of the expansion joint main body 210 and the expansion/shrinkage member 220. The expansion joint support member 240 has a flat structure and is formed of steel.
The anchor bolts 250 fix the hinge shaft support member 230 and the expansion joint support member 240 to the concrete slabs of the deck slabs 205a and 205b. That is, one ends of the anchor bolts 250 are welded to the hinge shaft support member 230 and the expansion joint support member 240, respectively, and after-cured concrete is poured to the other ends of the anchor bolts 250, to which nuts and washers are fastened, to thereby fix the hinge shaft support member 230 and the expansion joint support member 240 to the deck slabs 205a and 205b.
The rubber seal 260 is disposed under the expansion joint main body 210 and detachably installed between opposite ends of the deck slabs 205a and 205b to collect rainwater and foreign substances.
FIGS. 5 and 6 are views showing the structure of the rubber seal more specifically, in which FIG. 5 shows an assembled state and FIG. 6 shows an exploded state.
Referring to FIGS. 5 and 6, the rubber seal 260 includes a rubber seal main body 450 for collecting rainwater and contaminants, guide rollers 452 for detachably installing the rubber seal main body 450, and guide rails 454 for fixing and rolling the guide rollers 452.
As shown in FIG. 6, a plurality of guide rollers 452 fixed to both ends of the rubber seal main body 450 by guide roller fixing members 452g are parallelly installed along edges of the rubber seal main body 450. In this state, the guide rollers 452 are inserted into inner grooves of the guide rails 454 such that the rubber seal main body 450 is detachably installed between opposite ends of the deck slabs 205a and 205b through the medium of the guide rails 454. In FIG. 6, reference numeral 453 designates a connection ring for connecting the guide roller fixing members 452g to each other, reference numeral 455 designates a connection member for connecting the guide rails 454 to each other, and reference numeral 456 designates a wire used to install the rubber seal main body 450, at which the guide rollers 452 are installed, to the guide rails 454.
The following is a further description of manufacture and installation of the rubber seal main body 450 and the guide rail 454.
First, in manufacturing the rubber seal main body 450, as shown in FIG. 6, after press fitting the guide roller fixing members 452g, to which the guide rollers 452 are attached, into an upper end of the rubber seal main body 450, the guide roller fixing members 452g are press fitted into the rubber seal main body 450 using rubber fixing pins (screw). Then, the guide roller fixing members 452g are connected to each other by flexible connection rings 453 formed of a resin material. In addition, the guide roller fixing member 452g is manufactured such that its length can be adjusted depending on field conditions, thereby obtaining the effect of being bent to some extent during conveyance and installation.
In manufacturing the guide rail 454, in the case of an exposed guide rail as in FIGS. 6A and 6B to be described later, a corrosion resistance material, for example, stainless steel, aluminum, or a resin-based material, is used to maintain sealing to prevent introduction of rainwater from an upper part thereof. While the guide rail 454 is basically extruded in a factory, the guide rail 454 should have the length sufficient to be readily conveyed and installed. In addition, the guide rail 454 needs to be attached to the concrete slab by the anchor. Further, when a space is too narrow to attach the guide rail, the guide rail may be attached to the vertical part of the lower plate by welding. At this time, in the case of the exposed guide rails, the guide rails need to be disposed at different heights so that the opposite guide rails do not interfere with each other even when the expansion joints maximally approach each other. Connection between the guide rails 454 is made using a separate coupling 455 to prevent introduction of rainwater or foreign substances into the guide rails and secure smooth rotation of the guide roller 452.
FIGS. 6A to 6C are views showing various installation examples of the rubber seal according to the present invention.
Referring to FIG. 6A, there is shown a closed guide rail (a basic guide rail) 454 which includes a guide roller 452 having two wheels. At this time, the guide rail 454 is fixed to a steel main body or a concrete wall 600.
Referring to FIG. 6B, there is a ring-shaped guide rail 457 which includes a guide roller 458 having a single wheel. At this time, the guide rail 457 is also fixed to a steel main body or a concrete wall 600, like the closed guide rail.
Referring to FIG. 6C, there is a buried guide rail 458 which has a guide groove 457h corresponding to the ring-shaped guide rail 457 of FIG. 6B formed in a steel main body 610. That is, the guide roller 458 is buried into the steel main body 610, which is different from that of the exposed guide rails of FIGS. 6A and 6B.
As described above, the respective coupling mechanisms of the guide rails and the guide rollers have substantially the same function and effect although they may have appropriate constitutions depending on conditions of bridges or other concrete structures, and construction sites.
Meanwhile, in installation of the guide rails 454, as shown in FIG. 7, the guide rails 454 are preferably sloped to a predetermined slant angle with respect to a horizontal surface such that the rubber seal main body 450 is sloped. This is to smoothly discharge the foreign substances and rainwater introduced into the rubber seal main body 450. For this purpose, as shown in FIG. 8, the guide rails 454 are horizontally installed and the rubber seal main body 450 is designed and manufactured to be sloped and then fastened to the guide rails 454 as the case may be, thereby obtaining the same effect as the guide rails 454 of FIG. 7 (i.e., the entire rubber seal is installed in a sloped manner).
Meanwhile, FIGS. 9A to 9C are views showing earthquake-resistant flat expansion joints using a hinge according to second, third and fourth embodiments of the present invention.
FIG. 9A shows a structure of an earthquake-resistant flat expansion joint using a hinge according to a second embodiment of the present invention. The second embodiment has almost same structure as the first embodiment (see FIG. 2) except that an expansion/shrinkage member 220 is connected to one end of the expansion joint main body 210 to accommodate behavior in X, Y and Z-axis directions caused by temperature variation of the expansion joint main body 210 and earthquakes and an expansion joint support member 240′ supports the expansion/shrinkage member 220. That is, in the second embodiment, the expansion joint support member 240′ has two sections, one having a flat plate structure and the other having a cylindrical inner periphery structure through which the expansion/shrinkage member 220 can freely reciprocate depending on the behavior of the expansion joint main body 210 while maintaining its shape as it is without compression or extension thereof, rather than making its entirety have flat plate structure as in the first embodiment.
FIG. 9B illustrates a structure of an earthquake-resistant flat expansion joint using a hinge according to a third embodiment of the present invention. The third embodiment has substantially the same structure as the second embodiment of FIG. 9A except that the expansion/shrinkage member 220′ is formed of a solid rubber plate, not the corrugated plate having hollows.
FIG. 9C illustrates a structure of an earthquake-resistant flat expansion joint using a hinge according to a fourth embodiment of the present invention. The fourth embodiment has substantially the same structure as the first, second and third embodiments in that the expansion joint main body 210 has a hinge structure except that expansion joint main bodies 210′ and 210″ are installed at the opposite slabs 205a and 205b, instead of connecting the expansion/shrinkage member 220 or 220′ to an end of the expansion joint main body 210. In particular, the one expansion joint main bodies 210′ and 210″ are installed to partially overlap each other. In other words, the one expansion joint main body 210′ is installed to move along a slope formed at a certain part of a body of the support member 240″ of the other expansion joint main body 210″, and the other expansion joint main body 210″ is installed to move along an upper surface of the one expansion joint main body 210′. In the fourth embodiment, the expansion joint can maintain optimal horizontality during behavior by expansion and shrinkage of the expansion joint due to temperature variation and earthquakes. In FIG. 9C, reference numeral 270 designates a rolling plate for facilitating movement on the slope of the expansion joint main bodies 210′ and 210″.
FIG. 10 is a view showing a mechanism that the earthquake-resistant flat expansion joint using a hinge according to the present invention deals with vertical behavior in a Y-axis direction upon occurrence of earthquakes.
As shown in FIG. 10, when the vertical behavior in a Y-axis direction is generated due to earthquakes, the expansion joint main body 210 is hinged upward or downward, and the expansion/shrinkage member 220 connected to the end of the main body 210 is expanded or shrunk depending on characteristics of the corrugated structure having hollows or the rubber material to absorb or attenuate behavior of the main body 210. Therefore, it is possible to accommodate the behavior due to the earthquakes and avoid traffic disturbance.
FIG. 11 is a view showing a state that a main body of the expansion joint and an expansion/shrinkage member of the earthquake-resistant flat expansion joint using a hinge according to the present invention are separated from each other to remove contaminants accumulated in the rubber seal.
As shown in FIG. 11, when contaminants accumulated in the rubber seal 260 needs to be removed, after disassembling the fixing member 300 connecting the expansion joint main body 210 to the expansion/shrinkage member 220 to raise the expansion joint main body 210, the contaminants accumulated in the rubber seal 260 are removed through a gap (a space) therebetween, to readily remove the contaminants.
As can be seen from the foregoing, an earthquake-resistant flat expansion joint using a hinge according to the present invention an earthquake-resistant flat expansion joint using a hinge can improve the structure of a main body of the expansion joint to be moved in X, Y and Z directions, i.e., three axial directions upon occurrence of earthquakes to prevent damage to structure due to the expansion joint connected to the structures when slabs connected to the expansion joints, girders and breast walls of abutments are moved by the earthquakes, and avoiding traffic disturbance even through the earthquake occurs. In addition, even though the deck slab is separated from a bridge, the expansion joint can be recovered to the deck slab, without installation of a new expansion joint.
Further, the present invention can prevent secondary damage to a lower structure due to traffic jam caused by traffic control and delayed exchange of a damaged rubber seal by improving a rubber seal for collecting rainwater and foreign substances in a structure exchangeable independently from the expansion joint.
While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.
Patent Application
20090064602
