KR19990007573A - Construction and maintenance of continuous beam bridge using load - Google Patents

Abstract

Most of the continuous bridging methods that have been installed so far have generated cracks in the bottom plate concrete of the inner flank due to the construction without proper correspondence to the moments generated in the inner flank, Durability has been reduced.

In the construction method according to the present invention, in the construction and maintenance of the continuous beam bridge, the load is applied to the center portion of the bridge after installing and repairing the inner bridge portion, the bottom plate concrete of the moment section is poured and cured, This is a construction method of a continuous beam bridge which can prevent cracks by introducing compressive stress to the bottom plate of the bridge and to resist the moment caused by dead load and live load.

The method according to the present invention can be applied to the continuous beam bridge having three or more spans by repeating the same method.

Description

Construction and maintenance of continuous beam bridge using load

In most of the continuous bridging methods that have been applied so far, cracks have been generated in the bottom plate concrete of the inner point portion due to the construction without proper correspondence to the momentum occurring at the inner point portion, and the rigidity and durability . Especially, in PSC beam bridge, it is applied by continuous beam and beam as a simple beam shape. Since the moment redistribution due to the creep and drying shrinkage of concrete increases with time, the bottom plate of the momentum section Cracks are generated.

As a result, this crack has a disadvantageous structural dynamics. In other words, since it behaves close to a simple beam or a simple beam, large moments are generated in the section of the moment, and deflection and vibration are increased, which adversely affects the usability and durability.

The method of the continuous beam bridge using the load according to the present invention is characterized in that when the continuous beam bridge is installed, the load is placed near the center of the beam, the bottom plate concrete of the momentum section is laid and cured, And compressive stress is applied to the bottom plate of the section to prevent cracking.

Another feature of the method according to the present invention is that unlike a simple beam, the beams are continuous, so that the height of the beam can be reduced by 20 to 30% compared with a simple beam, and the beam can be greatly advantageously deflected and vibrated.

If the height of the beam is fixed, the material cost is reduced by about 20% compared to the conventional simple beam.

This method can be applied equally to the maintenance of continuous beam bridge.

The technical features of the present invention will be described with reference to the drawings.

Figure 1 shows the structural systems of the simple beams and the two span continuous beams and their respective moments. (A) is a simple beam structure system, which has been widely applied as a relatively simple structure, and (b) has a large positive moment and large deflection as shown in Fig. (C) In case of two span continuous beam structure system, the same span length (A) is compared with the simple beam system in And deflection is about .

However, as shown in Fig. 4 (d), the negative moment acts 1.78 times larger than the maximum moment, and this moment causes the tensile stress on the upper deck at the completion of the bridge. The present invention relates to a method of introducing compressive stress corresponding to a momentum in order to take advantage of the above-described continuous beam structure system, and will be described with reference to the drawings.

Figure 2 shows the construction method and each moment diagram of the PSS beam continuous beam bridge using the load. (A) shows a state in which a pierce concrete (P.S.C.) beam is simply mounted, and (b) a bottom plate concrete is excluded, except for a moment section about 4 m from the right and left of the inner point. In this case, the tensile steel of the moment section is buried in the bottom plate of the moment section to correspond to the tensile force generated when the load is loaded. At this time, the principle of the wedge can be used at the bottom of the reinforcing bar to increase the tension of the tensile reinforcement. In the case of a continuous beam bridge with a span length of 30 m, the length of 4 m of the inner flank is determined by parametric analysis of the length of the momentum section as a variable. This length is the most effective way to introduce compressive stress. And concrete materials. (C) The beam is connected to two beams using a cross beam, and then the load and moment are plotted on the center of the girder. In this case, the girder can resist the moment caused by the load load Should be designed. The load can be loaded in vehicles or steel bins. (D) shows the state and moments of loading the bottom plate of the leg section and removing the load. At this time, it is possible to use the point where the simple instruction is used as it is, but in order to facilitate the behavior of the continuous bridge, it is possible to remove the left and right points after installing one point indicated by bold line according to the field conditions. Through the construction process from (a) to (d), compressive stress is introduced to the bottom plate of the momentum section to resist the negative moment due to the dead load and the working load. This method can be applied not only to PSS beam continuous beam bridge but also to the bottom plate of the plate section and the upper section of the elevation bridge. Of course, the construction method according to the present invention can be applied to a continuous bridge having three or more spans by repeating the same method.

FIG. 3 shows a repair method of a PSS beam continuous beam bridge using a load. (A) shows the state of removing the bottom plate of the section where the crack occurred, and (b) shows the state and moment diagram of the beam installed on the center of the bridge. Here, the load is determined by calculating the amount of tensile steel reinforced on the bottom plate of the momentum section and the moment that the repaired beam can resist. At this time, the principle of the wedge can be used at the bottom of the reinforcing bar to increase the tension of the tensile reinforcement. (C) shows the state and moments of the loading of the bottom plate of the legend section and the load. Through the construction process from (a) to (c), compressive stress is introduced in the bottom plate of the momentum section to resist the moment caused by live load. This repair method can be applied to the maintenance method of the bottom plate of the vertical section of the plate type continuous bridge and the vertical section of the vertical bridge type. The repair method according to the present invention can be applied to a continuous bridge having three or more spans by repeating the same method.

Figure 4 shows the method that can be selected when installing and repairing a continuous beam using load. (A) shows the method of loading the entire beam at one time and piling the deck of the momentum section. When this method is used at the time of construction and repair, the structure calculation is simplified and the construction and maintenance period are shortened . However, the amount of load to be loaded increases during construction, and full control of the vehicle is required at the time of maintenance. (B) Loads and removes the load sequentially along the lane, and puts the bottom plate of the section of the moment. At the time of construction, two beams are successively made in the longitudinal direction by using the load, and they are connected by using the beam in the lateral direction. At the time of repair, the part of the lane is removed without removing all of the deck concrete, and the load is loaded. Then, the bottom plate concrete is poured, cured, and the load is removed and repaired. The same method is repeated for each lane to repair. In order to apply the load sequentially, it is necessary to calculate the structure for the lateral direction, but there is an advantage that maintenance can be performed while permitting the traffic of the vehicle to be maintained, and the load is simplified.

The above identifier is missing.

Fig. 1 shows the structural system and moment diagram of the simple beam and the two span continuous beams.

FIG. 2 is a view showing a construction method of a continuous beam bridge using a load according to the present invention

3 is a view showing a method of repairing a continuous beam using a load according to the present invention

FIG. 4 is a schematic view showing a temporary method and a sequential method

DESCRIPTION OF THE REFERENCE NUMERALS (S)

①Psess (P.S.C.) beam

② Bottom plate of concrete section

③ Raebo

④ Bottom plate of concrete section

⑤ In the top view of the continuous beam bridge, the bottom plate concrete

⑥ In the top view of the continuous beam bridge, the bottom plate concrete

⑦ Tension bars of bottom plate

The above identifier is missing.

The above identifier is missing.

Claims (2)

In the construction and maintenance of the continuous beam bridge, in the section where the moments of the moment section and the moment section are small, that is, about 90% of the bottom plate concrete is inserted with the beam length, , And the bottom plate concrete is poured and cured in a section where the moment of the moment section is large, that is, about 10% of the beam length, and then the load is removed to introduce compressive stress to the bottom plate of the moment section, A method of constructing a continuous beam bridge that can prevent the cracks caused by live moments caused by live loads. 1, the construction method in which tensile reinforcement is placed in advance at the bottom plate of the section of the momentum to endure the tensile force by the load.