KR200416542Y1 - Continuous preflex girder structure with prestress introduced into parent section using expanded concrete - Google Patents

Abstract

The present invention relates to a continuous preflex girder structure in which prestress is introduced into a parent section using expanded concrete, and an upper reinforcement sheet is installed in accordance with the upper surface of the bottom plate concrete in a section where the parent section occurs in the continuous bridge. The cement section is formed by a predetermined interval in the longitudinal direction of the structure by the expansion concrete is placed on the abdomen, haunch, bottom plate of the structure.

The continuous preflex girder structure in which prestress is introduced in the parent section using the expanded concrete proposed in the present invention and its construction method can omit the raising and lowering of the inner point as in the existing technology, making construction simple and fast. As such, it may be possible to use a bridge structure that can replace the existing technology.

Expanded concrete

Description

Continuous Preflex Girder Structure Using Prestress in Parental Section Using Expanded Concrete {.}

1 is a view showing a preflex girder structure of the prior art, which is the simplest form, from [FIG. 1A] to [FIG. 1D] showing a procedure for manufacturing a preflex girder structure.

FIG. 2 is a view illustrating a construction procedure of the continuous beam bridge of Korean Patent Publication No. 0099114, which is the cited invention, from [FIG. 2A] to [FIG. 2E].

[Figure 3] shows a continuous preflex girder structure and the construction method of the pre-stress is introduced into the parent section using the expanded concrete of the present invention [Fig. 3a] [Fig. 3c] is the construction order of the, [Fig. 3d ] Shows a perspective view of the completed structure.

[4] is a pre-stress introduction principle of the continuous preflex girder structure and its construction method to introduce the prestress in the parent section using the expanded concrete of the present invention [FIG. 4A] is an example of the front detail of the connection portion FIG. 4B is a plan view of FIG. 4A, and FIG. 4C is a detailed diagram for illustrating a theoretical explanation of the method of continuation of the present invention.

<< Description of main part of drawing >>

DESCRIPTION OF SYMBOLS 1 Steel beam 2: Concrete which covered the lower flange of steel beam 3: Abdomen, haunch and bottom plate concrete 10: Preflex girder 20: Upper connection steel plate 30: Expanded concrete

The present invention relates to a continuous preflex girder structure in which prestress is introduced into a parent section using expanded concrete. As a conventional technology, there is a simple beam preflex girder structure of the simplest form and a Korean Patent Publication No. 0099114, which is a cited invention. .

Referring to the structure of the prior art shown in Figure 1 as follows.

1 shows a preflex girder structure and a construction flowchart thereof. The preflex girder structure is a kind of prestress girder structure in which compressive force is applied to the concrete on the tension side. The lower flange is applied to the steel beam 1 having the I-shaped cross section by bending deflection due to the preflection load (see Fig. 1b). It is a structure 10 in which a compressive force is introduced into the lower flange concrete by coating the concrete 2 and then removing the preflection load (see FIG. 1C). In FIG. 1a, the preflex girder 10 manufactured as shown in FIG. 1c is mounted between shifts and piers in the field, and then the abdominal and haunch concrete and the bottom plate concrete 3 are poured to complete the bridge (see FIG. 1D). Such a preflex girder structure has a shape in which the upper flange steel of the preplex girder, which is a mold, is embedded in the bottom plate concrete, that is, the bottom plate concrete 3 serves as the upper flange of the preflex beam 10 at the same time. It has the lowest advantage compared to other types of bridges. However, the preflex girder structure of FIG. 1 is limited to a simple beam structure, and thus its use is extremely limited, and when applied to a continuous bridge, only the bottom plate concrete is continuized so that the bottom plate concrete of the inner branch portion is generated. There is a problem that tensile cracking occurs due to the cement.

Figure 2 shows the construction method of a continuous bridge bridge, which is a key part to compare the technology of the Korean Patent Publication No. 0099114 with the present invention.

The above patent discloses a girder used for continuous beam bridges to apply preflex girders, which have been used only for simple beam bridges, to continuous bridges, and when the manufactured preflex girder is applied to continuous bridges, secondary fixed and live loads are applied. The method of introducing compressive stress into the bottom plate concrete was used to raise and lower the inner point in order to resist the parental moment caused by. The invention of the published patent has a problem of operational risk and process delay because it must add a process for raising and lowering the girder on the inner piers. In addition, when the structure itself has a blind spot, there may be a problem that the whole structure is twisted by the process of raising and lowering the inner point.

The present invention seeks to maximize the applicability of the method by developing a new structure that can compensate for the disadvantages of the prior art described above and constructing a bridge using the same.

The present invention has been devised for the purpose of solving the above-mentioned disadvantages of the prior art, the prior art has the disadvantage that not only used in the form of a simple bridge but also to raise and lower the inner point when applied to the continuous bridge.

의 콘크리트를 사용하는데 정모멘트 구간은 전 구간을 타설하며 부모멘트가 발생하는 구간은 일정한 간격을 두고 도 3b와 같이 부분적으로만 타설을 실시하는데 이는 타설이 안된 구간에 본 고안의 핵심인 팽창 콘크리트를 충전하기 위함이다. 또한 콘크리트의 타설과 동시에 상부보강강판(20)을 바닥판 콘크리트의 타설 면에 맞춰 설치한다. 여기서 설치하는 상부보강강판(20)은 추후 설명할 본 고안의 공정인 팽창 콘크리트의 프리스트레스 효과를 극대화시키기 위함이다. 다음 공정으로는 전술했듯이 일반 콘크리트가 타설이 안된 구간에 팽창 콘크리트(30)를 충전 타설하는 것을 도 3c에 나타내었다. 여기서 프리플렉스 거더와 거더의 연결부 하부플랜지에도 팽창 콘크리트를 타설한다. 3d는 이의 상태를 나타낸 사시도이다. Figure 3 is a continuous preflex girder structure and the construction method of the pre-stress is introduced into the parent section using the expanded concrete of the present invention, Figure 3a to 3c is a construction sequence for manufacturing the structure, Figure 3d is completed A perspective view of the structure is shown. 3a is a state diagram in which the preflex girders constituting the structure of the present invention are mounted on alternating and pier and connected to each other in an axial direction. The manufacturing method and form of the preflex girder produced here uses the manufacturing method of Korean Patent Publication No. 0099114, which is a cited invention of the prior art. Therefore, detailed description of the manufactured preflex girder will be omitted herein. 3b shows a state in which the formwork is installed on the mounted and connected preflex girders, and the abdomen, the haunch and the bottom plate concrete 3 are poured. At this time, the concrete to be poured is the strength generally used 270 ～ 400

The concrete moment of the concrete moment is cast all sections, and the section in which the parent moment occurs is placed only a portion, as shown in Figure 3b at regular intervals. To charge. In addition, at the same time the concrete reinforcement to install the upper reinforcing steel plate 20 in accordance with the pouring surface of the bottom plate concrete. The upper reinforcing plate 20 to be installed here is to maximize the prestress effect of the expanded concrete which is a process of the present invention to be described later. Next, as shown in FIG. 3C, the filling process of the expanded concrete 30 is filled in a section in which ordinary concrete is not poured as described above. Here, the expansion concrete is also placed in the lower flange of the connection between the preflex girder and the girder. 3d is a perspective view showing its state.

The following describes the principle of introducing prestress using expanded concrete, which can be said to be the core of the present invention.

만큼의 변형률이 발생하며 이 변형률은 종방향으로 변형률

에 팽창콘크리트의 단면적(

)과 팽창 콘크리트의 탄성계수(

)를 곱한 만큼의 하중(

)이 발생하는데(도 4c ①참조) 이 하중은 상부보강강판과 프리플렉스 거더 및 팽창 콘크리트가 합성된 단면(단면적

여기서

은 상부보강강판 및 프리플렉스 거더와 팽창 콘크리트의 강성비,

는 상부보강강판의 단면적,

는 프리플렉스 거더의 단면적)에 작용하여 합성된 단면에는 인장응력 (

)을 유발시킨다(도 4c ②참조). 따라서 팽창 콘크리트에서 발생하는 인장응력(

)은 상부보강강판과 프리플렉스 거더 및 팽창 콘크리트가 합성된 단면이 그를 저항하게 됨으로 결국 팽창 콘크리트에는 반대로 도 4c의 ③과 같이 압축응력(

)이 도입되어 본 고안에서 성취하고자 하는 종방향의 프리스트레스를 팽창 콘크리트만으로도 성취할 수 있는 것이다.4 is an explanatory diagram for implementing the prestress introduction principle of the present invention, for example, the detail of the connecting portion that generates the largest parent moment is shown in FIG. 4A and FIG. It is a top view showing. As shown in Fig. 4c, the expansion cement filled in the connecting portion expands both in the transverse direction and in the longitudinal direction, considering the expansion only in the longitudinal direction, which is the point of the present invention.

As much strain is generated as the strain in the longitudinal direction

The cross-sectional area of the expanded concrete

) And modulus of elasticity of expanded concrete

Load multiplied by

) Is generated (see Fig. 4c).

here

Stiffness ratio of upper reinforcement steel sheet and preflex girder and expanded concrete,

Is the cross-sectional area of the upper reinforcing steel sheet,

Acts on the cross-sectional area of the preflex girder)

) (See Fig. 4c ②). Therefore, the tensile stress that occurs in expanded concrete

), The cross section of the upper reinforcing steel plate, the preflex girder, and the expanded concrete resists the compressive stress.

), The longitudinal prestress to be achieved in the present invention can be achieved with expanded concrete alone.

The continuous preflex girder structure in which prestress is introduced in the parent section using the expanded concrete proposed in the present invention and its construction method can omit the raising and lowering of the inner point as in the existing technology, making construction simple and fast. As such, it may be possible to use a bridge structure that can replace the existing technology.

Claims (2)

The upper reinforcement plate is installed in the section where the parent moment occurs in the continuous bridge in accordance with the upper surface of the bottom plate concrete, and in the parent section, a certain interval is formed in the longitudinal direction of the structure to the abdomen, haunt, and bottom plate of the structure. Continuous preflex girder structure in which prestress is introduced into a parent section using expanded concrete, in which expanded concrete is poured In claim 1 Continuous preflex girder structure in which prestress is introduced into a parent section using expanded concrete, characterized in that the expanded concrete is filled between the lower flange and the lower flange of the connection part of the structure.

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