JP3865727B2 - Extrusion construction method - Google Patents

Description

  The present invention relates to a bridge girder extrusion construction method.

  In general, there is an extrusion construction method as a technique for constructing a continuous bridge girder having a span length of about 150 m or more with a span of 30 to 60 m. In the conventional technology related to the extrusion erection method, bridge girders are sequentially formed on the ground behind one abutment by cast-in-place construction, and a steel hand girder is attached to the end of the bridge girder and construction is performed by one-pressing from one direction. In this case, since the bridge girder is manufactured by cast-in-place construction, each process of formwork, rebar work, and concrete work is required in the bridging process. Therefore, there has been a problem that the construction work period is long (see, for example, Patent Document 1).

On the other hand, it is necessary to minimize the period of traffic interruption etc. especially in construction such as three-dimensional intersections at intersections in urban areas, and rapid construction of bridge girders is desired. In the conventional extrusion construction method, it is difficult to shorten the construction period, and in addition, the influence on the surrounding environment such as traffic regulation, traffic congestion, and noise accompanying construction is also regarded as important.
JP 2003-138522 A (page 2-4, FIG. 1)

  The present invention solves the above problems, and in the present invention, an improvement is made to the extrusion erection method, and the bridge girder can be constructed in a shorter construction period compared to the conventional one and minimizes the influence on the surrounding environment. Established construction method.

  The present invention aims to provide such an improved technique.

The present invention has been made in order to solve the above-described problems, and is a bridge girder extrusion construction method characterized by taking the following technical means. That is, in the present invention, when the bridge girder is extruded and installed, the bridge girder which is extruded from both banks while sequentially connecting the precast concrete bridge girder and butt-closes at the intermediate portion of the span is formed with the butt end face of each other as a match cast surface. In addition , the bridge girder extrusion construction method is characterized in that the butted end faces of both bridge girders are tightly joined with an adhesive .

Before SL butt closure for bridge beam is previously formed a butt end face of the mutually matching cast surface, since it was decided to close contact the butt end face can quickly correct construction.

  The match cast surface refers to a mutual surface between members in which the concrete of an adjacent concrete member is cast using the end surface of an existing concrete member as a mold and the shape of the end surface is transferred as it is. When the match cast surfaces are joined, the surfaces of each other are in close contact with each other.

  In the present invention, the bridge girder is constructed by forming and pushing out the bridge girder from both sides of the bridge section and closing at the center of the span. Therefore, the construction period of the bridge girder erection process is about one-half compared to construction from one side. In addition, in the conventional extrusion construction method from one direction, a light steel hand girder is attached to the end of the bridge girder, and it reaches the front pier ahead of the bridge girder, generating excessive cross-sectional force in a cantilevered state. Prevents the occurrence of deflection.

  Since the bridge girder tip is pushed out from both sides of the span to be closed, there is no problem even in a long span where a temporary support or the like cannot be installed. Although it is a single push between the spans other than the span to be closed, it is possible to prevent the generation of excessive cross-sectional force by installing temporary struts as needed or optimizing the span length design, etc. What is necessary is just to prevent generation | occurrence | production of a big deflection. Therefore, extrusion is performed without using a manual girder.

  In the bridge girder extrusion construction method, since the abutment surface of the bridge girder to be closed is match cast, the joint joint can be completely adhered by applying an adhesive.

  In the above-mentioned present invention, the male and female guide keys that are concavo-convexly fitted to each other are further placed on the butting surfaces that are to be closed and closed, and the male and female guide keys are fitted in the final pushing step to quickly and accurately close the closing portion. It is preferable to close.

  Further, in the above-described method of pushing and installing the bridge girder, a trumpet-shaped inlet is provided on the female side and a round head shape is provided on the male side at the fitting start position of the male and female guide keys. It is preferable because the tip can be easily aligned and the construction is simplified. At this time, there is no need for a jack or other special device for aligning the ends of the bridge girders, and the number of work steps can be shortened.

  According to the present invention, the bridge girder is sequentially extruded from both banks, and both bridge girders are butt-closed by the match cast method at the intermediate span portion, making use of all the advantages of the extrusion method and the short construction period. It can be constructed with a large amount of contribution.

  In addition, since the bridge girder of the closing part forms a joint surface by the match cast method, it is possible to ensure high integrity in the closing part and improve durability, as well as adhesive application for closing work. A simple work scaffold may be used.

  The construction of the closing portion has been conventionally performed by cast-in-place concrete, which requires scaffolding, formwork, reinforcement, concrete work, a bonding stress introduction process, etc., but these are unnecessary. Accordingly, it is not necessary to install a work scaffold or the like for a long time, and the work required for closing can be performed only by traffic regulation for one night.

  Further, since the closing portion can automatically align the center axes of the end faces with the guide key as the bridge girder is pushed out, the closing can be performed with high accuracy in a short time. Therefore, large-scale equipment and man-hours such as jack-up using a support work are not required at the time of closing.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 5 is an explanatory view showing an overall side view of the embodiment of the present invention. Extrusion work floors 30a and 30b are provided on both banks, and the bridge girders 40a and 40b are extruded as indicated by arrows 33a and 33b, respectively, and both are pressed between the center diameters and closed. Each bridge girder 40a, 40b moves forward on the pier 31. However, in the spans other than the central span, the span span is shortened as necessary or the auxiliary bridge pier 32 is provided so as not to use the hand bridge girder. Design and plan.

  When closing and integrating bridge girders formed from both sides, a place joint is usually provided in the bridge girder closure part, and a concrete and concrete is placed by placing a formwork and a reinforcing bar in this joint part. Done. Therefore, each process of a formwork, a reinforcing bar, and a concrete work accompanying a cast-in-place construction is required. In addition, consideration for safety associated with work at high places, consideration for falling objects at intersections with roads, railways, etc., long-term questions during construction or multiple traffic restrictions, etc. are also required.

  FIG. 1 is a diagram showing a bridge girder extrusion construction method according to an embodiment of the present invention, and FIG. 2 is a side view of the bridge girder when the closing of the closing portion is completed. In the present invention, the front end surfaces 11a and 11b of the bridge girders 10a and 10b pushed out from both sides are set as joint surfaces formed in advance by a match cast method. The match cast method is a method in which concrete is cast using the end face of an existing segment as a formwork to produce an adjacent segment, and the joining surfaces of adjacent segments can be completely matched.

  At the time of closing work, use a simple work scaffold provided at the closing position, apply epoxy resin adhesive to the joint surface in advance, advance the bridge girder to bring the joint surface into close contact, and then temporarily install the steel Temporary fixing is performed using (temporary PC steel). Next, a continuous steel material is disposed in the span portion including the closing portion, and prestress is introduced into the bridge girder in the span portion to be integrated.

  FIGS. 3A and 3B are partial longitudinal sectional views showing the vicinity of the front end surface of the bridge girder at the end of the closing portion used in the practice of the present invention. FIG. 3 (a) shows a female guide key 51 having a recess in the leading end face and a bridge girder 10a provided with a support portion 52, and the AA arrow view is shown in the left half of FIG. FIG. 3B shows a configuration in which a male guide key 61 protruding from the leading end face of the facing bridge girder 10b and a support portion 62 are provided. The BB arrow line view of FIG.3 (b) was shown on the right half of FIG. The male guide key 61 is pressed and inserted into the female guide key 51 to be fitted therein, and serves to align the bridge beams 10a and 10b.

  In order to finely adjust the directions of the bridge girder end faces in the cantilever state of the closing portion to completely match each other, it is necessary to apply a certain external force to force the correction. For example, it is necessary to take measures such as starting up a support having a predetermined strength from the ground and forcibly displacing the ends of the bridge girders with a hydraulic jack or the like.

  In the present invention, fine adjustment of the joint surface in the extruding operation from both sides is performed using a dedicated male and female guide key previously installed on the segment of the bridge girder tip. The male and female guide keys have a convex shape on one side, a concave shape on the corresponding side, an enlarged entrance portion on the concave side, and a tip on the protruding side with a round head.

It is explanatory drawing which shows the construction of an Example. It is explanatory drawing which shows the construction of an Example. It is a fragmentary longitudinal cross-section which shows the closing part girder of an Example. It is a fragmentary longitudinal cross-section which shows the closing part girder of an Example. The left half is an AA arrow view of FIG. 3 (a), and the right half is an BB arrow view of FIG. 3 (b). It is explanatory drawing of the extrusion construction method of extruding from both banks of an Example.

Explanation of symbols

10a, 10b Bridge girder 11a, 11b End face 30a, 30b Extrusion work floor 31 Bridge pier 32 Auxiliary pier 33a, 33b Arrow 40a, 40b Extrusion bridge girder 51 Female guide key 52 Support section 61 Male guide key 62 Support section

Claims (3)

When the bridge girder is extruded and installed, the bridge girder that is extruded from both banks while sequentially connecting the precast concrete bridge girder and butt-closes in the middle part of the span is formed with the mutual butt end face formed on the match cast surface. Extrusion construction method of bridge girder characterized by tightly joining the butt end faces with an adhesive . The male and female guide keys that are concavo-convexly fitted to each other are placed facing each other on the butting surfaces to be closed and closed, and the male and female guide keys are fitted in the final pushing process to close quickly and accurately. 1. Extrusion construction method of bridge girder described in 1. 3. The bridge girder extrusion construction method according to claim 2 , wherein a trumpet shape and a round head shape are provided at the fitting start positions of the male and female guide keys, respectively .

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