KR20010114109A - A reinforced earthquake-proof device - Google Patents

Abstract

The present invention relates to a seismic reinforcement device for a piers installed in a piers, which are pillars of a bridge, so that the piers can be supported even when a large displacement such as an earthquake occurs, and a construction method using the piers.

The present invention provides a thin plate-like support plate attached to a lower outer periphery of a piers installed upright on the ground so as to support the top plate, and a predetermined depth formed in a foot formed in the brackets attached to the upper end of the support plate. A plurality of rebars inserted into the grooves; An outer shell which is equidistantly spaced to accommodate the reinforcing bars installed in the outer circumference of the piers and is installed to match the height of the reinforcing bars on the foot; It is made of concrete; is poured into the interior of the shell to cure.

Therefore, the present invention is devised to provide a proper seismic structure applied to the bridge facing the earthquake while supporting the charge of the bridge, in particular, it can be applied as it is to the already existing bridge bridge, easy and inexpensive installation It is an effective and useful invention that provides a device and a construction method thereof.

Description

A reinforced earthquake-proof device

The present invention relates to a seismic reinforcement device for a piers installed in a piers, which are pillars of a bridge, so that the piers can be supported even when a large displacement such as an earthquake occurs, and a construction method using the piers.

Large displacements caused by large loads at the same time, such as earthquakes, cause large structures to suffer from such expansion as the displacement expands and even overturns, thus, especially large bridges. There is a good contrast for this, for example, seismic bridge device installed between the piers and the top plate, and the device for preventing the fall of the top plate.

However, in the piers erected on the ground, up to now, the seismic piers were designed to increase the size of the piers so as to receive the expected additional load at the rated design load. However, with the spread of the perception that our country is not an earthquake safe zone, such measures are being taken. As a part of such measures, seismic retrofit mechanisms are disclosed in Korean Patent Publication Nos. 99-78977-9, As a special structure applied to the wooden building, the research on the bridge piers has been insufficient.

The present invention has been made to provide an appropriate seismic structure applied to a bridge facing an earthquake while supporting the charge of the bridge, in particular, can be applied as it is to the already existing bridge, it is easy and cheap to install The study has been completed to provide a device and its construction method, which will be described in detail with reference to the accompanying drawings.

1 is another partial configuration state of the present invention,

2 is an excerpt and a cross-sectional view of the main part of FIG.

3 is another configuration of the present invention,

4 is an extract of another configuration of the present invention,

FIG. 5 is a construction process diagram of FIGS. 1 and 3 according to the present invention. FIG.

* Explanation of the Major Codes in Drawings

1. Pier

11.Foot 12. Groove

2. Support plate

21. Bracket 22. H beam

3. Rebar

31. Horizontal rebar

4. Concrete

5. Outer shell

6. Slab

1 is a state diagram of a concrete (4) before placing so as to know the internal parts of the seismic reinforcement device of the present invention, Figure 2a is an enlarged state diagram of the excerpt A of the main part of Figure 1 which is one configuration of the present invention, 2B is a cross-sectional view taken along line BB of FIG. 1 in a completed state (after concrete pouring) of the present invention.

The present invention is a thin plate-like support plate (2) attached to the outer periphery of the lower end of the piers (1) installed upright on the ground to support the upper plate (6) to the enemy; A plurality of reinforcing bars (3) inserted into a bracket (21) attached to the upper end of the support plate (2) and inserted into a recess (12) of a predetermined depth formed in the foot (11) formed in the bridge (1); An outer shell 5 installed at the height of the reinforcing bar 3 on the foot 11 at an equidistant distance to accommodate the reinforcing bar 3 installed in the outer circumference of the piers 1; It is preferable to be characterized by consisting of; concrete (4) is poured into the inside of the shell (5) to cure.

Figure 3a is a partial excerpt of another configuration of the present invention.

In the above-described configuration, the bracket 21 is a conventional H beam 22, and the reinforcing bar 3 is inserted into a hole drilled in the web portion of the H beam 22. More preferred.

Figure 4 is an extract of another configuration of the present invention as shown in Figure 1 shows the state before the concrete (4).

In the above configuration, it is more preferable to include at least one horizontal reinforcing bar 31 for fixing and fixing the reinforcing bar 3 in the horizontal circumference.

3B is a partial state excerpt illustrating a preferred variant of the present invention.

In addition to the configuration described above, an H beam 22 attached to the support plate 3 is added below the bracket 21, and the reinforcing bar 3 is installed to penetrate the central hole of the H beam 22. Modified examples are also preferable from the structural point of view.

FIG. 5 is a construction process diagram of FIGS. 1 and 3 according to the present invention. FIG.

The apparatus of the present invention is constructed in the following manner, which is an example of a preferred one of the various construction methods for constructing the embodiment of the present invention, and it is apparent that the present invention is not limited to the present construction method.

A thin plate-like support plate 2 is attached to the outer periphery of the lower end of the piers 1 which are installed upright on the ground to support the upper plate 6 at an enemy; A plurality of brackets 21 are attached to the upper end of the support plate 2 so that a plurality of reinforcing bars between grooves 12 having a predetermined depth formed in the foot 11 formed in the pier 1 in the bracket 21 3) is inserted; Placing an outer shell (5) on the foot (11) equidistantly spaced to receive the reinforcing bars (3) installed in the outer circumference of the pier (1); Placing concrete (4) in the shell (5) to complete the construction of the present invention.

According to one configuration of the present invention, the support plate 2 is in the form of a thin plate is attached to the outer periphery of the lower end of the pier 1 is installed upright on the ground to support the upper plate 6, the lower plate of the pier 1 Since the outer circumference is covered and attached to the pier with a piece or stud bolt, the foundation reinforcement in the pier (1) is not damaged so that the basic design load is not damaged.

In addition, a plurality of reinforcing bar (3) is inserted into the bracket 21 attached to the upper end of the support plate 2 a plurality of grooves 12 of a predetermined depth formed in the foot (11) supporting the pier (1) Since the reinforcement (3) forming the skeleton of the reinforcement portion is inserted into the foot (11) is to give a large support force. At this time, the foot 11 is included in any structure of any shape that is installed so that the pier (1) is not settled by the soft ground at the bottom of the pier (1), the foot is submerged under water or too small When it is difficult to make a structure mentioned above, you may attach and construct a structure separately, and even if it is such a construction, it is only an embodiment of this invention, and is within the technical scope of this invention.

In addition, the outer shell (5) is equidistantly spaced to accommodate therein the reinforcing bars (3) installed on the outer periphery of the pier (1) is installed at the height of the reinforcing bars (3) on the foot (11); Since the concrete 4 is poured into the shell 5 and cured, the support plate 2, the reinforcing bar 3, the shell 5, and the concrete 4 have the greatest external force during the earthquake, resulting in the pier. It is possible to improve the bearing capacity by overlaying the outer circumference of the predetermined portion (parts less than 1/3 at the lower end of the pier 1) where the damage of the pier 1 is expected. 5) is closely attached to the outer periphery of the reinforced concrete (4), so that even if a large external force such as an earthquake is applied, the concrete of the piers (1) and the concrete for reinforcement (4) can be prevented from being destroyed and destroyed. It is a means.

According to another configuration of the present invention, since the bracket 21 is a conventional H beam 22, the reinforcing bar 3 is inserted into a hole drilled in the web portion of the H beam 22, The material can be used as a conventional H-beam 22 to provide convenience in manufacturing and installation. However, when the beam is not the columnar shape of the piers 1 but is a cylindrical shape, the H-beam 22 is rounded to match the outer circumference of the column. It may be difficult to work because it needs to be bent, but since the H beam 22 functions as a support for the reinforcing bar 3, it must be closely adhered to the outer periphery of the piers 1 to not fully exert its function. Some error is allowed, and when the reinforcing bar 3 is inserted into the hole drilled in the web portion, which is the center of the H beam 22, the method of fastening with a nut on the upper part of the rib of the H beam 22 is used. Easy to install, vertical installation It said easily, and can also provide the same effects so that by attaching the nut to the lower ribs, without puncturing the H-beam 22 by welding, etc. The reinforcement 3 is sapjang.

According to another configuration of the present invention, since the reinforcing bar 3 includes at least one horizontal reinforcing bar 31 to fix the horizontal reinforcement, the reinforcing bar 3 is supported by the bracket 21 The horizontal reinforcement 31 is fixed in a grid-like connection to one or a plurality of positions of the middle part, so that when it is embedded in the concrete 4 to be poured later, it functions as a backing reinforcement of the concrete 4 to form a rigid skeleton. At this time, as a method of connecting the horizontal reinforcement 31 to the reinforcing bar (3), tag-wealding the positions orthogonal to each other, or a more easy way is to tie the orthogonal part with a wire to fix it Even if a firm coupling is not made between the reinforcing bar 3 and the horizontal bar 31, all of them are embedded in the concrete 4, so there is no problem in strength.

The installation specification of this invention is given and demonstrated to an Example.

<Example>

First, the thin-plate shell 5 was attached to the outer periphery of the lower end of the piers 1 installed upright on the ground so as to support the upper plate 6 (FIG. 5A state). At this time, the pier (1) is a cube of width × length × height (2m × 2.5m × 20m), the maximum vertical load (dead load + live load) is 400Ton and the maximum horizontal load (earthquake) is designed to 100Ton, the support plate ( 2) was used in close contact with the bottom of the piers 1 using a sheet steel of 2mm thickness (FIG. 5A state).

Next, a plurality of brackets 21 are attached to the upper end of the support plate 2 so that a plurality of reinforcements are formed between the grooves 12 of a predetermined depth formed in the foot 11 formed in the pier 1 in the bracket 21. Reinforcing bar 3 was inserted (FIG. 1 state). At this time, the reinforcing bar (3) was placed 18mm diameter bars at intervals of 50cm.

Finally, the shell 5 is erected at a height of the reinforcing bar 3 above the foot 11 at an equidistant distance to accommodate the reinforcing bar 3 installed therein. 5b state) The concrete 4 was poured into the shell 5 to cure. At this time, the outer shell 5 was a 5 mm thick steel plate, and the distance between the support plate 2 and the outer shell 5 was 25 mm.

The groove 12 may be formed by drilling, etc. in the position of the foot 11 without the base reinforcement, anchor reinforcement 32 is to be installed by inserting strongly in the groove 12, as another construction method It is more preferable to attach the anchor reinforcement 31 to the foundation reinforcement in the foot 11 (welded or bundled with wires) so as to project the predetermined height onto the foot 11 while reflecting the design in advance in the initial bridge installation. As another installation specification, even if the bridge is already installed, a method of cutting the installation location of the foot 11 to expose the foundation reinforcing bars, attaching it, and then re-installing concrete for the foot 11 may be used. It is apparent that the present invention does not exceed the technical scope of the present invention even if it employs the technical idea of the present invention as it is.

Comparing the strength between the pier reinforced with the embodiment and the general pier as follows.

The compressive stiffness of concrete σ _ck = 270㎏ / ㎠, the elastic modulus of concrete E _c = 2.5 × 10 ⁵ kg / ㎠, cross-sectional area Ac is horizontal × vertical = 5.0㎡,

[Equation ^{1] Z = LW 2/6} (L is horizontal, W is vertical)

Substituting this in Equation 1, the cross-sectional coefficient Zc of the general piers is obtained.

Zc is a ^{= 2.5 × 2 2/6 =} 1.667㎥.

Since the tensile stress σ _sy = 2500 kg / cm 2 of SS400 (steel) and the elastic modulus of steel E _s = 2.1 × 10 ⁶ kg / cm 2,

Η = E _s / E _c

Substituting this into Equation 2, the concrete value of the cross-sectional area η of steel is obtained.

η = 2100000/250000 = 8.4

Acs = Ac + As (Acs is the converted cross-sectional area of the steel-concrete composite, As is the cross-sectional area of the steel)

The converted cross-sectional area of the reinforcement bridge of the present invention,

And Acs = 2.05 × 2.55 + 8.4 × (9 × 0.002 + 9.2 × 0.005 + 0.00025 × 18) = 5.80 , and the section modulus of the reinforcing bridge columns are ^{Zcs = 2.55 × 2.05 2/6} = 1.786 in equation (1),

[Equation 4] Mmax = Hmax × h

The maximum bending moment Mmax is 100 × 20 = 2000 Ton · m according to the above equation 4,

Σp = Vmax / A (Vmax is the maximum vertical load)

If the average compressive stress (σpc and σpcs) of ordinary piers and reinforcement piers is obtained by the above equation 5,

sigma pc = 400,000 / 5 x 10 ⁴ = 8.0 kg / cm 2,

σpcs = 400,000 / 5.80 × 10 ⁴ = 6.90㎏ / ㎠

[Equation 6] sigma b = Mmax / Z

If the maximum bending stress (σbc and σbcs) of the general piers and reinforcement piers is obtained by the above equation 6,

σbc = 2000 × 10 ⁵ /1.667 × 10 ⁶ = 120.0 kg / cm 2,

sigma bcs = 2000 x 10 ⁵ /1.786 x 10 ⁶ = 112.0 kg / cm 2.

However, the main point of the design is how much the structure can withstand the forces acting on the outside, which is called the Danger Index (DI), and it is determined that the larger the DI is, the safer the structure is. 7,

DI = Ca / D (Ca is the compressive strength of the structure, D is the stress)

The stiffness of the existing piers and the reinforcement piers by Equation 7 is shown in Table 1.

TABLE 1

Demand (㎏ / ㎠) Compressive strength (㎏ / ㎠) Stiffness (DI) Remarks Vertical Stiffness (㎏ / ㎠) Existing Pier 8.0 270 33.75 15.9% increase Reinforced piers 6.9 270 39.13 Flexural Rigidity by Horizontal Force (㎏ / ㎠) Existing Pier 120.0 270 2.25 9.92x increase Reinforced piers 112.0 2500 22.32

The vertical stiffness was slightly increased and there was no big difference than expected effect between the existing piers and the reinforcement piers. However, this is not the point because the existing piers are sufficiently loaded, and the biggest effect is the bending strength. This is about 10 times, which is a big increase, because the outer shell exerted by the bending moment is made of steel of SS400.

The present invention has been made to provide an appropriate seismic structure applied to a bridge facing an earthquake while supporting the charge of the bridge, in particular, can be applied as it is to the already existing bridge, it is easy and cheap to install An effective and useful invention for providing an apparatus and a construction method thereof.

Claims (3)

A thin plate-like support plate (2) attached to the outer periphery of the lower end of the piers (1) installed upright on the ground to support the upper plate (6) to the enemy; A plurality of reinforcing bars (3) inserted into a bracket (21) attached to the upper end of the support plate (2) and inserted into a recess (12) of a predetermined depth formed in the foot (11) formed in the bridge (1); An outer shell 5 installed on the foot 11 at an equidistant distance to accommodate the reinforcing bars 3 installed in the outer circumference of the piers 1; Concrete (4) is poured into the inside of the shell (5) to cure; Pier seismic reinforcement device, characterized in that consisting of. The method of claim 1, The seismic reinforcing device of the piers, characterized in that the bracket 21 is a conventional H beam (22), the reinforcing bar (3) is inserted into the hole drilled in the web portion of the H beam (22). The method according to claim 1 or 2, The seismic reinforcement device of the piers, characterized in that it comprises at least one horizontal reinforcement (31) for fixing the reinforcing bars (3) in a horizontal circumference.