JP2005220526A - Overhead crossing and its construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an overhead crossing and its construction method capable of greatly shortening a construction period of time. <P>SOLUTION: The overhead crossing 1 comprises a plurality of pre-cast footings 2 forming a foundation of an arch bridge among multi-paths, pre-cast piers 3 erected on the pre-cast footings 2, pre-cast arch ribs 4 on the pre-cast footings 2 and constructed among the paths and pre-cast stiffening girders 5 supported by the pre-cast piers 3 and the pre-cast arch ribs 4. When the center among the paths 11 is built up, a movable vehicle 71 and a mounting jack 72 are used as a support. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a three-dimensional intersection composed of a multi-span arch bridge overpassing a road or a railway, and a construction method thereof.

Currently, for the purpose of preventing traffic congestion in urban areas, planning and construction of three-dimensional intersections consisting of underpasses or overpasses are being actively carried out so as to be orthogonal to transportation means such as roads and railways.
When constructing the underpass, construct shafts on both sides of the road or railway, and promote the steel pipes between the shafts to build after the portal support construction, or construct by other propulsion methods or shield methods Has been done.
On the other hand, when constructing an overpass, the following examples are given.
(1) A construction method that constructs foundations, piers, bridge girders, etc. by completely or partially blocking existing roads to create detours. In this case, there are various foundation structures such as a pile foundation and a direct foundation. For example, in the case of a direct foundation, the foundation is constructed by on-site concrete construction after excavation to a predetermined depth.
(2) When overpassing on the main line, especially on the railway, use the nighttime when there is no route operation after building the foundation on the side of the railway, constructing girders by hand, or placing support on the railway It is constructed and installed while hanging the precast girder with a crane or the like using the support.

The conventional three-dimensional intersection and its construction method have the following problems.
<1> If the three-dimensional intersection is carried out on site from the foundation to the pier and bridge girder, the construction period will be prolonged. In addition, when a detour or the like exists for a long period of time, smooth traffic obstruction or traffic congestion will occur for a long period of time.
<2> Of the three-dimensional intersections, even if the bridge piers and bridge girders are precast, if the foundation structure such as footing is built on site, it is unlikely that the construction period will be significantly shortened.
<3> When a bridge girder is erected on the main line, much of the work time will be spent on the construction and removal of support structures. Therefore, it is difficult to secure a substantial bridge girder construction time in the case of nighttime construction only.

  In order to solve the above problems, the three-dimensional intersection of the present invention includes a plurality of precast footings constituting the foundation of a multi-span arch bridge, a precast pier standing on the precast footings, and the precast footings. The precast arch rib spanned across the span, and the precast stiffening girder supported by the precast pier and the precast arch rib.

  In addition, the three-dimensional intersection of the present invention is a section where the center span is overpassed on the road or on the rail in the three-dimensional intersection, and the footings are connected by a connecting material between the spans other than the center span. It is a three-dimensional intersection with a structure.

Furthermore, the construction method of the three-dimensional intersection of the present invention is the above-described method of constructing the three-dimensional intersection, in the construction method of the multi-span arch bridge, at the time of assembling or disassembling at least the center diameter among the spans constituting the multi-span arch bridge, A construction method for a three-dimensional intersection characterized in that a jack mounted on a mobile vehicle is used as a support.

The three-dimensional intersection and its construction method of the present invention can obtain at least one of the following effects by means for solving the above-described problems.
<1> In the structure of a three-dimensional intersection, in addition to the piers and bridge girders, the foundations such as footings can be precast, so that the construction period can be greatly shortened.
<2> Since the precast bridge girder is erected using the mobile vehicle as a supporting work, the time required to install and remove the supporting work can be greatly shortened, so that it is possible to secure the bridge girder installation time.
<3> Consists of multi-diameter arch bridges, and by constructing the arch bridges as slender as possible, construction of a three-dimensional intersection with excellent aesthetics can be realized.

<1> Configuration of a three-dimensional intersection The three-dimensional intersection 1 of the present invention is formed from an arch bridge between multiple spans. The configuration includes a precast footing 2, a precast pier 3, a precast arch rib 4, and a precast stiffening girder 5 (see FIG. 1). That is, the main purpose is to realize the construction of the three-dimensional intersection 1 with a significantly shortened construction period by precasting all the components including the footing. Of course, the footing installed in the ground can be constructed by on-site concrete construction after excavation as in the prior art, in addition to installing the precast footing 2.

A precast pier 3 is erected on a precast footing 2 installed at a predetermined interval, and a precast arch rib 4 is stretched between the precast footings 2 and 2. Each span-length precast stiffening girder 5 is installed while being supported on the precast arch rib 4 and the precast piers 3 and 3.
The three-dimensional intersection 1 is basically configured such that the central span 11 is a section overpassing a road or a railroad. In that case, on the precast arch rib 4 spanned across the central span 11 A plurality of intermediate struts 41 are preferably provided. This is because the center span 11 is longer than the other spans, so that the member size of the precast stiffening girder 5 installed in the center span 11 does not become large.

  Each precast member constituting the three-dimensional intersection 1 is preferably manufactured in a factory using high-strength lightweight concrete in order to reduce the weight and ensure the required strength characteristics. The three-dimensional intersection 1 constructed by using each component member made of high-strength lightweight concrete can realize an excellent aesthetic from the combination of the slender members. However, the material used is not limited to high-strength lightweight concrete, but can be selected from a variety of materials such as ordinary concrete and high-strength fiber reinforced concrete, and the concrete specifications can be changed for each member.

The structural characteristics of the arch bridge are that the vertical load such as dead loads such as stiffening girders and arch ribs, traffic loads, etc., becomes horizontal forces through the arch ribs, and resists the horizontal forces applied by the footings supporting the arch ribs and the soil behind them. Need to be built to get. The arch bridge is originally constructed so as to cross the mountain valley in consideration of the horizontal force, and the horizontal force can be supported by the slope of the mountain. The three-dimensional intersection 1 of the present invention is assumed to be constructed on a flat ground such as an urban area. When an arch bridge is constructed on such a flat ground, it is necessary to have a structure that can resist the horizontal force. Therefore, it is preferable to connect the precast footings 2 and 2 with the connecting material 6 between the diameters other than the center distance 11 (see FIG. 1). Here, the connecting material 6 may be a cast-in-place concrete or a precast product, and may be a beam member or a plate member. It will be designed so that it can resist the horizontal force consisting of dead load and traffic load by the frictional force between the connecting material 6 and the ground. Further, by providing the connecting material 6, it is possible to suppress horizontal displacement of the precast footings 2 and 2 (or on-site footing) installed at both ends of the central span 11 as much as possible.

<2> Member Joints Each precast member is in principle manufactured as a product having dimensions of each span unit (span length unit), and the members are anchor bars 82 and PC steel ( For example, a three-dimensional intersection 1 can be constructed in a short time by joining with a PC steel rod or the like.

FIG. 2 shows the structure of the joint portion between the precast arch rib 4 and the precast stiffening girder 5 at the crown portion of the center span 11. An elastic bearing such as a rubber bearing 83 is preferably provided between the precast arch rib 4 and the precast stiffening girder 5. Further, since the center span 11 is longer than the other spans, the two precast arch ribs 4 and 4 and the two precast stiffening girders 5 and 5 are joined at the crown portion, respectively. (See FIG. 2). In this case, it is preferable that the members are tension-bonded to each other with PC steel.
The precast stiffening girder 5 and the precast arch rib 4 can be joined by an anchor bar 82, for example.
For the other spans, the precast stiffening girders 5 and 5 are preferably joined on the precast pier 3.

In FIG. 3, the structure of the junction part of the precast footing 2 (or spot cast footing), the precast pier 3 and the precast arch rib 4 is shown. The precast pier 3 has a structure in which the legs of the precast pier 3 (becomes wide) are embedded in the precast footing 2. Between the precast pier 3 and the precast arch rib 4, for example, a rubber cushioning material 84 and a rubber support 83 are provided. The two are joined by the PC steel 81 or the anchor bar 82.

<3> Construction method of level crossing The level crossing 1 construction method of the present invention will be described with reference to FIGS.
Construction of spans other than the central span 11 among the three-dimensional intersections 1 composed of multi-span arch bridges, that is, installation of the precast footing 2, standing of the precast pier 3, and spanning of the precast arch rib 4 are performed in a predetermined construction order. It is done at.
The feature of the construction method of the three-dimensional intersection 1 of the present invention resides in the installation of the precast arch rib 4 and the precast stiffening girder 5 at the center span 11. In the conventional construction method, the arch rib and the stiffening girder support are installed on the trunk line overpassing. Therefore, construction was performed at night when the main line was a railway and completely or partly impassable when it was a road. In addition, a great deal of time is spent on installing and removing the support works, and the substantial time for installing the arch ribs and stiffening girders becomes very short, resulting in a prolonged construction period. It was.
Therefore, in the present invention, at least the precast arch rib 4 (and the precast stiffening girder 5) having the center span 11 is installed, for example, a jack 72 (for example, a hydraulic jack) mounted on the rear portion of the mobile vehicle 71 such as a trailer is supported. Use as In the embodiment shown in FIG. 4, two mobile vehicles 71 and 71 are used in parallel. The precast arch rib 4 is installed by using the crane 91 and is locked to the precast pier 3 and the mobile vehicle 71 that have been installed in advance, and then joined by the anchor bar 82 or the PC steel 81 as described above.
After the precast arch rib 4 is spanned at the center span 11 and joined to the precast pier 3, the jack 72 is jacked down so that the mobile vehicle 71 can be retracted (see FIG. 5).
By using the mobile vehicle 71 as a support as in the present invention at the center span 11 where quick construction is required, the time required for the installation and removal of the support can be omitted, which is efficient. Construction becomes feasible.

A vertical section of a three-dimensional intersection. The side view which showed the junction part of a precast arch rib and a stiffening girder. The side view which showed the junction part of a bridge pier, a precast arch rib, and a footing. The front view which showed the condition where the bridge girder was constructed using a mobile vehicle as a supporting work. The side view which showed the condition where the bridge girder was constructed using a mobile vehicle as a supporting work.

Explanation of symbols

1 ... Solid intersection 11 ... Center span 2 ... Precast footing 3 ... Precast pier 4 ... Precast arch rib 5 ... Precast stiffening girder 6 ... Connection Material 71 ... Mobile vehicle 72 ... Jack

Claims (3)

A plurality of precast footings that form the basis of a multi-span arch bridge;
A precast pier erected on the precast footing;
A precast arch rib on the precast footing and spanned across the span;
It consists of the precast stiffening girder supported by the precast pier and the precast arch rib,
Multi-level crossing.
In the three-dimensional intersection according to claim 1,
The center span is a section overpassing on the road or on the railway, and in the span other than the center span, the footings are connected by a connecting material.
Multi-level crossing.
In the construction method of the three-dimensional intersection of Claim 2,
When carrying out assembly or disassembly of at least the center span among spans constituting a multi-span arch bridge, the mobile vehicle and a jack mounted on the mobile vehicle are used as a support work,
How to construct a three-dimensional intersection.

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