JP3716233B2 - Construction method of PC viaduct - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for installing a PC viaduct.
[0002]
[Prior art]
When a viaduct is installed, there are cases where the use of the underpass space of the viaduct to be installed is restricted, such as construction of a viaduct at a three-dimensional intersection. For example, there are roads and railways with a high traffic volume below the viaduct, deep valleys, rivers, or the sea, or there are buildings, buildings, structures, and the like. Examples of the viaduct erection method employed in such a case include a cantilever beam extension method, an extrusion method, a moving support method, or a method using an erection girder. As these construction methods, appropriate construction methods are adopted according to the scale of the whole bridge, the scale of the under-girder space where use is restricted, the mode, and the like.
[0003]
In the cantilever beam extension method, a precast block or cast-in-place concrete is extended from both sides of the bridge pier while alternately balancing the left and right sides, and the bridge body and the tip that are extended from the adjacent pier are joined at the center of the span. This is a cross-linking method. Suitable for construction of large bridges between long and multi-spans.
[0004]
In the extrusion method, a bridge body is added at one end of the bridge, and the bridge body is advanced forward to bridge the bridge. At the top end, a girder girder is attached, and this girder girder is attached to the other pier. Extruded with support on top. Conventionally, in such an extrusion method, there have been points to be considered in construction, such as a reaction platform (bridge pier or abutment) stability and stress level check, and assembly and dismantling of hand-rolled beggers.
[0005]
The construction method using a moving support or erection girder is to hang a girder or temporary girder that hangs or places a girder, etc., and uses these to carry and erode the girder.
[0006]
[Problems to be solved by the invention]
In the case where the bridge body to be bridged is in a condition where there is a three-dimensional intersection between the spans of about 40 to 60 m in span and the underarm space cannot be used for the bridge construction, the bridge for such a condition is used. The purpose is to provide a suitable construction method.
[0007]
In the case of crosslinking between relatively small to medium scale diameters with spans of about 40 to 60 m, it is considered appropriate to use an extrusion method.
a) The construction period is extended because one end of the bridge is extruded while it is successively added and manufactured.
[0008]
b) It is necessary to use a hand-rolled girder, which takes time to install and remove.
[0009]
c) Effective use is not possible for spans that can be cross-linked by effectively using the under-sparing space.
There are problems such as.
[0010]
The present invention solves the above-mentioned problems, and only spans where the under-girder space cannot be used are installed in the same way as the extrusion method, and other parts under which the under-girder space can be used are used. It is an object of the present invention to provide a technique capable of performing efficient crosslinking.
[0011]
[Means for Solving the Problems]
The present invention provides a method for constructing a viaduct between spans where the under-girder space cannot be used as described above, and the technical means is that the construction diameter under conditions where the under-sparing space cannot be utilized for construction. When constructing a continuous viaduct spanning 3 spans or more including a gap, a bridge having a length obtained by adding approximately ½ of the span between the spans between adjacent spans on both sides in the bridge axis direction between the spans Each of the bodies is constructed, the bridge bodies on both sides are connected with external PC cables, the cables are pulled to pull the bridge bodies together, and the pulled bridge bodies are connected at the center of the span of the construction of the PC viaduct It is a construction method.
[0012]
In the present invention, among continuous bridges of 3 spans or more, one span where the under-girder space cannot be used is constructed by a method similar to the extrusion method, and approximately half the bridge girder length between the spans plus the adjacent diameter A bridge body with a length longer than that between them was produced on both sides, and this bridge body was pushed out from both sides between the diameters and joined at the center. The present invention does not require a hand girder. Furthermore, it was decided to towing the cable connecting the opposite sides of the bridge body as extruding means mutually the bridge body from both sides draw the bridge member to each other. That is, both the bridge member using an external cable, it erection is advanced while inquiries from one another.
[0013]
According to the present invention, only a viaduct such as a three-dimensional intersection can be independently constructed regardless of other spans other than the front and rear spans. Depending on the construction method, etc., the construction can be performed efficiently, so that the entire construction period can be greatly shortened. In addition, according to the above-described erection method, the bending moment distribution is not greatly different between the completed system and the erection system, so that the hand girder is not required, and the amount of temporary steel material can be reduced.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. First, a conventional extrusion method will be described with reference to FIGS.
[0015]
FIG. 5 is an explanatory diagram of the centralized extrusion construction method, in which the bridge body 41 sequentially assembled at one end is extruded and installed on the piers 51, 52, 53, 54,. In FIG. 5, there is a road with a large amount of traffic below the span between the piers 52 and 53, and the undergrowth space cannot be used for bridge construction. Conventionally, as shown in FIG. 5, the reinforcing bars of the bridge body 41 are assembled in the reinforcing bar assembly yard 61, concrete is cast in the girder manufacturing yard 62, and the bridge body is manufactured, and the extrusion yard 63 is attached to the anchor bracket. The tension steel rod 65 is pushed out by the bridge body extruding device 64. The leading end of the hand girders 42 is supported by a sliding bearing 43 provided on the pier. Since the hand girder 42 is a reinforced lightweight girder, the amount of drooping due to the deflection of the tip is small even if it is projected forward from the pier, and can be placed on the next pier. Accordingly, it is possible to guide the span while supporting the tip of the heavy concrete bridge body 41. FIG. 6 shows the details of the extrusion propulsion portion of the bridge body 41 of FIG. The bridge body 41 manufactured in the girder manufacturing yard 62 is pushed forward in the direction of the arrow 69 while sliding on the sliding support 68. The advancement is performed by attaching an anchor bracket 67 to the bridge body 41 and pulling a tensile steel member 65 coupled to the anchor bracket 67 with a girder pushing device 64. The girder extruding device 64 includes a jack reaction force base 71 attached to the top of the pier 51 and a center hole jack 72 that pulls the steel rod 65 while supporting the reaction force on the jack reaction force base 71.
[0016]
In this extrusion method, firstly, the girder 42 is assembled and sequentially extruded while producing the bridge body 41 at the tail end, and the girder at the tip is disassembled and removed at the end of the construction of the entire bridge body. This extrusion method is suitable for the construction of a bridge body with a span of about 100 m or less under the condition that the under-sparing space cannot be used, but there are many spans that can use the under-sparing space. In the case where there is one span where the under-sparing space cannot be used, it becomes inefficient.
[0017]
FIGS. 7 and 8 are explanatory views of a conventional distributed extrusion erection method. The construction of the bridge girder and the method of extrusion are the same as those of FIGS. 5 and 6 except that the girder extrusion devices 73, 74, 75, and 76 are connected to each pier. It is the one prepared above.
[0018]
1 to 4 are schematic views showing the method of the present invention. The present invention is a technique for constructing one span 12 where the underarm space cannot be used. The piers between the spans 12 and the spans adjacent to the spans are designated as 11a, 11b, 11c, and 11d. The span 12 between the bridge piers 11b and 11c is the span span.
[0019]
As shown in FIG. 1 (a), support works (girder production mounts) 31 and 32 are constructed between the spans between the piers 11a and 11b and between the piers 11c and 11d, respectively. 22 is made. At this time, the bridge bodies 21 and 22 are long bridge bodies that are approximately half the length of the target span 12.
[0020]
As shown in FIG. 1B, the bridge bodies 21 and 22 are extruded onto the target space 12 as indicated by arrows 23 and 24, respectively. At this time, since the length of the bridge body extruded onto the target span 12 is approximately ½ of the target span 12, it is not necessary to attach a hand-drawn girder to the tip. Also, the pulling device and the reaction force table may be smaller than an appropriate amount of extrusion method.
[0021]
As shown in FIG. 1 (c), the center of the target span 12 is closed using a suspension support to form a continuous girder.
[0022]
In this case, as shown in FIGS. 2 to 4, if the PC outside cable is bridged between the bridge bodies 21, 22, it is necessary to provide the traction device and the reaction force base on the pier side. It may be absent or very small. In FIG. 2, a PC cable 27 provided at the end of the bridge body 21 or 22 is inserted, a jack 28 is attached to the end of the PC cable 27, and the PC cable 27 is connected between the bridge bodies 21 as shown in FIG. Cross and tow. As for the construction of the bridge body having a span other than the span to which the present invention can be applied, the construction using the under-girder space can be carried out simultaneously in accordance with the actual situation.
[0023]
On the other hand, in this invention, since it constructs by half on both sides, the extrusion weight of a bridge body becomes half and the force which acts on a reaction force stand becomes small. Therefore, the stability of the reaction table and the safety of the stress level are improved. Moreover, since a hand-rolled bekader becomes unnecessary compared with the conventional extrusion method, the construction safety is also improved.
[0024]
【The invention's effect】
According to this invention, this invention provides the construction method suitable for bridge | crosslinking when there exists conditions which cannot utilize lower space, such as a three-dimensional intersection, between the diameters of the intermediate part span 40-60m of the bridge body which should be bridge | crosslinked. It is for the purpose. According to the present invention, it is possible to construct only a three-dimensional intersection or the like alone, and the other parts can be constructed efficiently by a construction method using a underarm space, etc., so that the entire bridge construction period is greatly shortened. I can do it. Since the bending moment distribution does not differ greatly between the completed system and the erection system, the amount of erected steel can be reduced. On the other hand, in this invention, since it constructs by half on both sides, the extrusion weight of a bridge body becomes half and the force which acts on a reaction force stand becomes small. Therefore, the stability of the reaction table and the safety of the stress level are improved. Moreover, since a hand-rolled bekader becomes unnecessary compared with the conventional extrusion method, the construction safety is also improved.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a construction method of the method of the present invention.
FIG. 2 is an explanatory diagram in which a PC cable is bridged between the bridge bodies and pulled.
FIG. 3 is an explanatory diagram in which a PC cable is bridged between the bridge bodies and pulled.
FIG. 4 is an explanatory diagram in which a PC cable is bridged between the bridge bodies and pulled.
FIG. 5 is an explanatory view of a conventional centralized extrusion erection method.
6 is a detailed view of an extrusion propulsion portion of the bridge body of FIG. 5. FIG.
FIG. 7 is an explanatory view of a conventional dispersion-type extrusion erection method.
FIG. 8 is an explanatory diagram of a distributed extrusion construction method.
[Explanation of symbols]
11, 11a, 11b, 11c, 11d Bridge pier 12 Spacing span 21, 22, 41 Bridge body 23, 24, 69 Arrow 25 Suspension support 26 Through hole 27 PC cable 31, 32 Support work (girder production stand)
42 Girder 51, 52, 53, 54 Bridge pier 61 Reinforcement assembly yard 62 Girder production yard 63 Extrusion yard 64 Bridge body extrusion device 65 Tensile steel rod 67 Anchor bracket 68 Sliding bearing 69 Arrow 71 Jack reaction force base 72 Center hole jack 73 74, 75, 76 Girder Extruder

Claims (1)

When constructing a continuous viaduct spanning 3 spans or more, including the span between the spans where the under-girder space cannot be used for the span, the length of the span between the spans is set on the adjacent spans on both sides in the bridge axis direction between the spans. Build a bridge with a length of approximately 1/2 length , connect the bridges on both sides with external PC cables, pull the cables and pull the bridges together, and connect the pulled bridges to the span span A PC viaduct erection method characterized by bonding at the center.

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