Patent Application
20090277124
The present invention relates to an apparatus for connecting a pre-cast deck slab with a beam on a bridge; more particularly, to an apparatus for connecting a pre-cast deck slab with a beam on a temporary bridge capable of precisely and securely connecting the pre-cast deck slab with the beam and preventing the connection part from being slackened due to live load after installing the bridge; and more particularly, to a method of connecting a pre-cast deck slab with a beam capable of rapidly, readily and stably connecting the pre-cast deck slab with the beam using the connection apparatus integrally buried in the pre-case deck slab.
Generally, bridges are constructed and used for traffic between a position and another position, or other purposes. Meanwhile, in addition to the permanent bridges, a temporary bridge is temporarily or semi-permanently installed for traffic of construction vehicles, workers or passersby, or rapid installation of the bridge.
The temporary bridge is constructed by first connecting beams to each other or installing a temporary vent or a bridge post at the ground using concrete, connecting a plurality of bars or beams to an upper end of the temporary vent or the bridge post, and installing a deck plate or a pre-cast deck slab on the beam. In addition, the temporary bridge may be constructed by a method of introducing a pre-cast using a high-strength steel bar, and a method of continuously and repeatedly assembling trusses.
In the meantime, as shown in
However, the conventional temporary bridge may cause several problems. That is, when the pre-cast deck slab formed of concrete is punched to connect the pre-cast deck slab with the beam, the deck slab is damaged due to impact. In addition, inconsistency between diameters of the holes and bolts cause gaps between the bolts and holes. These damages and gaps cause release of the bolts due to live load applied after installation of the bridge. Further, friction between the bolts and the concrete deck slab cause damage to the bridge to decrease safety of the bridge.
Further, in a conventional connection method between the beam and the pre-cast deck slab, since the pre-cast deck slab is punched using an additional tool to make operations complicated and unstable, it is impossible to rapidly and securely connect the pre-cast deck slab with the beam.
In order to solve the foregoing and/or other problems, it is an aspect of the present invention to provide an apparatus for connecting a pre-cast deck slab with a beam on a bridge capable of stably, rapidly and securely connecting and fixing the pre-cast deck slab to the beam.
It is another aspect of the present invention to provide a method of connecting a pre-cast deck slab with a beam on a bridge capable of stably, rapidly and securely connecting and fixing the pre-cast deck slab to the beam using the connection apparatus integrally installed at the pre-cast deck slab.
The foregoing and/or other aspects of the present invention may be achieved by providing an apparatus for connecting a pre-cast deck slab with a beam including: a main body buried in the pre-cast deck slab and having a hollow part formed in an axial direction thereof; a plurality of support portions integrally formed with an outer surface of the main body, each of which has a body having a certain length and a hook integrally formed with an end of the body; a bolt having a bolt body inserted into the hollow part of the main body and a fixing hole of the beam, and a head integrally formed with an upper end of the bolt body; and a nut threadedly engaged with the bolt body.
The bolt body may have a thread and the hollow part of the main body may have a thread so that the bolt body is threadedly engaged with the hollow part.
The plurality of support portions may be spirally disposed on an outer surface of the main body in a reverse direction of the threaded direction formed at the bolt body, and the body of each support portion may have a plurality of projections.
The hollow part of the main body may have a thread formed at a portion of a lower end thereof.
The end of the bolt body may have a fastening part having a smaller diameter than the inner diameter of the hollow part and the outer diameter of the bolt body to pass through the hollow part of the main body, the fastening part may have a thread, the thread of the fastening part may be formed in a reverse direction of the thread of the bolt, and the thread formed at the hollow part of the nut may be detachably fastened to the thread of the fastening part.
Another aspect of the present invention may be achieved by providing a method of connecting a pre-cast deck slab with a beam including: pouring concrete on the connection apparatus disposed in a concrete form to form the pre-cast deck slab with the connection apparatus buried therein, punching a plurality of fixing holes at appropriate positions of the beam through which bolts are inserted, and installing a deflection member at a center lower part of the beam; moving the pre-cast deck slab and the beam to a construction site at which bridge posts are installed, and disposing both ends of the beam on two bridge posts; arranging a plurality of pre-cast deck slabs on the beams disposed on the bridge posts; fixing one end of a steel wire to one end of the beam and disposing a center part of the steel wire at a deflection member to fix the other end of the steel wire to the other end of the beam in a state that the pre-cast deck slab and the beam are disposed on the two posts, and maintaining the beam in a freely sagging state; primarily tensioning the steel wire using a pre-stressing means to align the hollow part of the main body with the fixing hole to horizontally maintain the beam when the beam disposed on the bridge posts at its both ends are sagged due to the weight of the beam and the weight of the pre-cast deck slab; inserting the bolt into the hollow part of the main body and the fixing hole of the beam when the hollow part of the main body is aligned with the fixing hole of the beam, and fastening a nut to the bolt from the beam to connect and fix the pre-cast deck slat) with the beam; and secondarily tensioning the steel wire to correspond to a rated live load of moving means passing through the deck slab when the pre—cast deck slab is connected to the beam.
In accordance with an apparatus for connecting a pre-cast deck slab with a beam and a method of connecting a pre-cast deck slab with a beam using the same of the present invention, it is possible to connect the pre-cast deck slab with the beam using bolts and nuts in a state that a main body having a support part is buried in the pre-cast deck slab and integrated therewith before installation of a bridge, and rapidly and securely connecting and fixing the pre-cast deck slab to the beam to increase stability.
Further, since there is no necessity of punching holes for inserting bolts into the pre-cast deck slab, it is possible to prevent damage to the pre-cast deck slab. Furthermore, release of the bolts and damage to the pre-cast deck slab due to live load after installation of the bridge can be prevented to improve reliability.
In addition, the pre-cast deck slab can be rapidly and securely connected and fixed to the beam using the connection apparatus integrated with the pre-cast deck slab to improve operation performance.
The above and other aspects and advantages of the present invention will become apparent and more readily appreciated from the following description of exemplary embodiments, taken in conjunction with the accompanying drawings of which:
a is a view showing stress distribution generated by a conventional bolt connection type of
Herein after, the embodiments of the present invention will be described in detail with reference to the accompanying drawings.
Referring to
As shown in
And also, in the main body 10, a hollow part 12 is formed to insert a bolt 30 therethrough. The hollow part 12 passes in an axial direction of the main body 10.
A plurality of support portions 20 are installed at an outer surface of the main body 10, and are buried in the pre-cast deck slab 50 together with the main body 10. It is preferable that each support portion 20 is integrally formed with the outer surface of the main body 10, and is formed in a direction perpendicular to the axial direction of the main body 10.
Each support portion 20 includes a body 22 integrally formed with the main body 10 and having a predetermined length, and a hook part 24 integrally formed with an end of the body 22. The hook part 24 increases a contact area with the pre-cast deck slab 50 formed of concrete to securely support the main body 10.
In addition, each support portion 20 may be formed at the outer surface of the main body 10 in various manners. For example, as shown in
Further, the present invention includes the bolt 30 to be inserted into the hollow part 12 of the main body 10 and the bolt 30 securely connects and fixes the pre-cast deck slab 50 to a beam 60 substantially. The bolt 30 basically includes a bolt body 32 passing through the hollow part 12 of the main body 10 and having a thread 32a threadedly engaged with a nut 40, and a head 34 integrally formed with an upper end of the bolt body 32. In an actual engagement, as shown in
The nut 40 is detachably fastened to an end of the bolt body 32 of the bolt 30 to fix the bolt 30 with the pre-cast deck slab 50 and the beam 60. A hollow part 42 having a diameter corresponding to the diameter of the bolt body 32 of the bolt 30 is formed at a center of the nut 40, and a thread 42a threadedly engaged with the thread 32a formed at the bolt body 32 of the bolt 30 is formed at the hollow part 42.
Meanwhile, as shown in
Further, as shown in
Selectively, as shown in
In particular, a fastening part 36 having a smaller diameter than an inner diameter of the hollow part 12 and an outer diameter of the bolt body 32 is formed at an end of the bolt body 32 of the bolt 30 to freely pass through the hollow part 12 of the main body 10. It is preferable that the fastening part 36 has a thread 36a formed in a reverse direction of the thread 32 formed at the bolt body 32 of the bolt 30. As described above, the reason for differently forming the direction of the thread 32a of the bolt body 32 of the bolt 30 from the direction of the thread 36a of the fastening part 36 is in order to prevent release of the bolt by fastening the bolt when live load after installation of a bridge is applied to the bolt 30 to cause the bolt 30 to be rotated in a release direction.
Of course, when the fastening part 36 is formed at the bolt 30, a diameter of the hollow part 42 of the nut 40 must correspond to a diameter of the fastening part 36 of a bolt 30, and the thread 42a formed at the hollow part 42 should be detachably fastened to the thread 36a formed at the fastening part 36 of the bolt 30.
Hereinafter, a method of connecting a pre-cast deck slab with a beam using the connection apparatus as described above will be described with reference to
First, an operator disposes the connection apparatus of the present invention on an appropriate position of a concrete form (not shown), and then, pours concrete to form a pre-cast deck slab 50 with the connection apparatus buried therein. In addition, a fixing hole 62 through which a bolt 30 is inserted is punched at an appropriate position of a beam 60, and a deflection member 64 is installed at a center lower part of the beam 60 (S100 of
As described above, after the pre-cast deck slab 50 and the beam 60 are moved to a construction site, at which bridge posts 70 are installed, both ends of the beam 60 are disposed on the two bridge posts 70 (S110 of
In addition, the plurality of pre-cast deck slabs 50 are arranged and disposed on the beam 60 disposed on the bridge posts 70 (S120 of
In a state that the pre-cast deck slab 50 and the beam 60 are disposed on the two bridge posts 70, an operator fixes one end of a steel wire 80 to one end of the beam 60, after disposing a center part of the steel wire 80 at a deflection member 64, fixes the other end of the steel wire 80 to the other end of the beam 60 or a support beam, and maintains the beam 60 in a free sagging state (S130 of
When the beam 60 disposed on the two bridge posts 70 at both ends of the beam 60 is sagged due to the weight of the beam 60 and the weight of the pre-cast deck slab 50, one end or both ends of the steel wire 80 are tensioned to horizontally maintain the beam 60 using a pre-stressing means (not shown) to align the hollow part 12 of the main body 10 with the fixing hole 62 of the beam 60 (S140 of
As described above, when the hollow part 12 of the main body 10 is aligned with the fixing hole 62 of the beam 60 by tensioning and horizontally maintaining the beam 60, after inserting the bolt 30 into the hollow part 12 of the main body 10 and the fixing hole 62 of the beam 60, the nut 40 is fastened to the bolt body 32 of the bolt 30 or the fastening part 36 from the beam 60 to connect and fix the pre-cast deck slab 50 to the beam 60 (S150 of
Meanwhile, as shown in
In particular, as shown in
Finally, when the pre-cast deck slab 50 is connected with the beam 60, the steel wire 80 is secondarily tensioned to correspond to a rated live load of moving means passing over the deck slab (S160 of
After installation of the bridge, even though the live load due to vehicles or passersby is applied to the pre-cast deck slab 50 and the bolts 30, it is possible to securely fasten the bolt 30 by the main body 10 and the nut 40 and to prevent the bolts 30 from being released or loosening.
As shown in
Here, the bolt used in the conventional bolt connection method has the same diameter as the bolt 30 in accordance with the present invention, and a ratio of the diameters of the bolt 30 and the main body 10 is 1:2. In this condition, when the same horizontal load (bridge axial load) of about 50 kgf/cm2 is applied, tensile stresses of ambient concrete through finite element analysis are shown in the following table 1.
According to Table 1, while the connection apparatus including the cylindrical main body 10 integrally formed with the plurality of support portions 20 and the bolt 30 had the concrete generation stress of 10.9 kgf/cm2, the conventional bolt connection method had stress of 37.6 kgf/cm2. Eventually, a ratio of tensile stresses applied to the concrete was shown as 1:3.4.
When the connection method using the connection apparatus in accordance with the present invention is used, rather than the conventional bolt connection method, since it is possible to reduce the stress generated in the concrete more than three times when the pre-cast deck slab is connected with the beam, it is possible to stably connect the deck slab with the beam and stably maintain the entire bridge.
Therefore, in a steel frame bridge, the pre-cast deck slab can be stably fixed to the beam, and the pre-cast deck slab can be rapidly, readily and stably connected with the beam.
The present application contains subject matter related to Korean patent application NO. 10-2006-0115853, filed in the Korean Patent Office on Nov. 22, 2006. the entire contents of which being incorporated herein by reference.
The forgoing description concerns in exemplary embodiment of the invention, is intended to be illustrative, and should not be construed as limiting the invention. The present teachings can be readily applied to other types of devices and apparatuses. Many alternatives, modifications, and variations within the scope and spirit of the present invention will be apparent to those skilled in the art.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2006-0115853 | Nov 2006 | KR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/KR2007/005030 | 10/15/2007 | WO | 00 | 10/21/2008 |
