JPH07233508A - Pier, and pier-constructing method by means of self-climbing form installation - Google Patents

Abstract

PURPOSE:To attain the labor saving of the working of constructing a pier, to shorten a construction period of the work, and to reduce the cost of the work, by a method wherein when a concrete high pier with a hollow crosssection is constructed, the work of setting-up reinforcements is extremely reduced and the work of installing scaffolds and forms, inside and outside, is made unnecessary. CONSTITUTION:A hollow pier main body 1 is composed of RC structure wherein all screw- threaded PC steel bars 2 are used as longitudinal reinforcements and high strength concrete 4 is used, the work of setting-up reinforcements is extremely reduced, and the weight thereof is lightened. In the construction thereof, after temporary structural steel members 25 to be buried are installed, a structural steel block A with the all screw-threaded PC steel bars parallel to the longitudinal direction of a pier is set-up, following which inside and outside form units 23, 24 for self-climbing forms 20 are installed and the concrete 4 is placed between the inside form unit 23 and the outside form unit 24. The work of installing the temporary structural steel members, the work of setting-up the structural block A, the work of lifting and installing the self-climbing forms and the work of placing the concrete are repeated in that order, and the construction is done to a specified height. In this way, the usual work of installing and removing scaffolds and forms, inside and outside, is made unnecessary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bridge pier for a bridge constructed in a mountainous area and a method of constructing a bridge pier by a self-elevating formwork method.

[0002]

2. Description of the Related Art RC structures are generally used for concrete bridge piers in the bridge. Conventionally, RC is used to assemble scaffolds and use a tower crane to perform formwork assembly, rebar assembly, concrete placement, and formwork disassembly. The construction method is adopted.

[0003]

The maximum height of existing piers is about 79 m, but recently, a number of piers exceeding 100 m are planned for road bridges in mountainous areas.
When such a high pier is constructed by the conventional RC method, a large amount of work is required for the reinforcing bar work, and since it has a hollow cross section for weight reduction, it is necessary to install scaffolds and formwork inside and outside, It takes a lot of labor and time to work,
It takes about twice as long as a normal pier,
Moreover, there is a problem that the price becomes high.

The present invention has been made to solve the above-mentioned problems, and the purpose thereof is to significantly reduce the work of reinforcing bars, eliminate the conventional work of scaffolding and formwork inside and outside, and construct piers. The purpose of the present invention is to provide a bridge pier construction method that can save labor, shorten the construction period, and reduce costs, and a bridge pier construction method using the self-propelled formwork method.

[0005]

The pier of the present invention is based on the RC structure, adopts a high strength full-strength PC steel rod that is easy to join to the axial direction and has a high strength. use. The total screw PC steel rod is preassembled as a steel block and connected with a coupler and a nut. The stirrup as the lateral streaks is also preassembled as a block.

According to the method of constructing a pier of the present invention, a temporary embedded steel frame for supporting and self-elevating a self-elevating formwork (climbing form, etc.) that rises intermittently is installed first, and then the pier axial direction is set. Assemble a steel block with a total screw PC steel rod along with, install the inner and outer molds of the self-elevating formwork inside and outside this steel block, and between the inner and outer molds. A concrete pier is constructed, a steel block is assembled, a self-elevation formwork is raised and installed, and concrete is sequentially laid to build a pier.

[0007]

With the above construction, the adoption of the full-screw PC steel rod significantly reduces the number of reinforcing bars as compared with the conventional RC method. In addition, the adoption of high-strength concrete makes it possible to reduce the weight of the cross section in combination with the adoption of the full-screw PC steel rod.

Further, since the inner mold and the outer mold are self-elevating molds, there is no need for the conventional set-up work for the inner and outer molds / scaffolds, which saves labor and speeds up the work.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an illustrated embodiment. This is 100m on the road bridge in the mountains
1 and 2 (a) are vertical and horizontal cross-sectional views showing the pier, and Figs. 3 (a) and 3 (b) are joints of PC screw with full screw. Side view showing the block, perspective view,
FIG. 4 is a perspective view showing a stirrup, FIGS. 5 (a) and 5 (b) are a front view and a side view showing an example of a climbing foam, and FIG. 6 is a schematic side view showing a construction procedure.

As shown in FIGS. 1 and 2, the pier main body 1 has a hollow cross section, and a full-threaded PC steel rod 2 as an axial ridge.
Then, the RC structure including the stirrup 3 as the lateral streaks and the high-strength concrete 4 is used.

The total screw PC steel rod 2 is a high-strength reinforcing bar,
When arranging at a predetermined pitch on the outside and inside of the hollow cross section, and using, for example, Gevin Destorve (trade name), the diameter can be made as small as 36 mm with respect to the rebar D51 of the conventional RC method, and the arrangement pitch It can be made large (see Figure 2). Furthermore, the compressive strength σ = 6 commensurate with this total screw PC steel rod 2.
By adopting the high-strength concrete 4 of about 00 kgf / cm ² , the cross-sectional area can be made smaller than the conventional one, and the own weight can be reduced.

The total screw PC steel rod 2 is prefabricated into a steel material block A having a predetermined height, and after being assembled, these steel rod blocks are connected by a coupler 6 and a nut 7 shown in FIG. 3 (a). FIG. 3 (b) shows an example of a prefabricated steel rod block A, in which all-threaded steel rods 2 are arranged on four side surfaces of a rectangular parallelepiped steel suspension frame 8 and fixed by nuts 9. The total screw steel rods 2 adjacent to each other have different projecting lengths from the upper and lower surfaces to facilitate connection.

Further, the stirrup 3 is also a reinforcing bar block B, and as shown in, for example, FIG. When hoisting with a tower crane or the like, it is untied, and after being built in the steel rod block A, the untied is untied and lifted.

As shown in FIG. 5, the climbing foam 20 has an inner support frame 21 and an outer support frame 22 fixed to the already cast frame, and is mounted on the support frame so as to be movable back and forth with respect to the frame. It is composed of an inner mold 23 and an outer mold 24.

Further, as shown in FIG. 2 (a), the pier body 1
In the cross section of, the temporary embedded steel frame 25 is arranged on each side,
Further, as shown in FIG. 1, it is arranged in advance in advance of the steel rod block A and the reinforcing bar block B so as to protrude from the total screw PC steel rod 2 at the upper end by a predetermined length. The temporary embedded steel frames 25 are members that do not bear an axial load, and, for example, about two pieces are arranged on each side in the cross section of the pier main body 1.

At the time of ascending, the inner supporting frame 21 and the outer supporting frame 22 are supported by such a temporary embedded steel frame 25, and are raised by the elevating device. As shown in FIG. 1, for example, the supporting device and the elevating device include an upper suspension structure 26 attached to the upper end of a temporary embedded steel frame, a suspension wire rope 27 suspended from the upper suspension structure 26, and the wire rope 27. And a lift jack (center hole jack) 28 for gripping and raising the support frames 21 and 22.

The lift jacks 28 are support pedestals 21 and 22.
It is installed on the upper or upper suspension pedestal 26, and the suspension wire rope 27 is gripped and fixed to support the pedestals 21 and 22.
In a state in which the support racks 21 and 22 are supported, the support racks 21 and 22 are removed from the body, the gripping device of the lift jack 28 is extended to grip the hanging wire rope 27, and the lift jacks 28 are contracted to raise the support racks 21 and 22. By repeating this, the support frames 21 and 22 are raised by a predetermined stroke.

When the cross section of the pier is tapered so as to gradually decrease in the axial direction, the inner mold frame 23 and the outer mold frame 24 each having four sides are combined in a rectangular shape, and each side is inside and outside. By advancing and retracting in the direction, it follows the cross-sectional change. As for the mold itself, one having a variable width is used, or a mold having a different width is changed each time the stroke is increased.

Needless to say, in the case of a straight straight section having an equal cross section in the axial direction of the pier, an integral climbing foam which does not require adjustment can be used.

With the above-mentioned structure, the pier is constructed by the climbing foam method as follows (see FIG. 6).

(1) A temporary embedded steel frame 25, the lower end of which is fixed to the basic concrete 30, is projected to a predetermined height.

(2) The base steel rod block A and the reinforcing bar block B are assembled by the total scaffold 31, and the high-strength concrete 4 is cast to construct the pier base 32.

(3) After temporarily fixing the temporary steel frame 25 to a predetermined height, the next steel rod block A is suspended on the pier base 32 by using a lift-up type tower crane 33 which is generally used. , The total screw PC steel rods 2 are connected with the coupler 6 and the nut 7.

(4) Reinforcing bar block B with the tower crane 33
Is hung on the steel rod block A and assembled.

(5) The climbing foam 20 is attached to the already cast frame, and the high-strength concrete 4 is cast between the inner mold 23 and the outer mold 24. When assembling a reinforcing bar block or the like or placing concrete, scaffolds attached to the inner mold 23 and the outer mold 24 can be used.

An embedded steel frame 25 for temporary construction is placed in advance on the top of the cast concrete. After the concrete is cured, the climbing foam 20 is raised by one step and fixed to the frame. By repeating ascending and fixing, assembling the steel rod block A and the rebar block B, and placing the high-strength concrete 5 in sequence,
The pier will be built to a certain height.

Although the road bridge in the mountainous area has been described above, it is needless to say that the present invention can be applied to high bridge piers of other bridges.

[0028]

As described above, according to the present invention, the RC structure employs the full-screw PC steel rod as the axial direction bar and the high-strength concrete, and the self-elevating formwork is used as the inner and outer formwork. It has the following effects.

(1) Since the axial reinforcing bar is replaced with a full-screw PC steel bar, the quantity can be reduced compared to the reinforcing bar, and since it can be easily added with a coupler and nuts, it saves labor and weather conditions. Construction is possible without being affected.

(2) By utilizing high-strength concrete, the self-weight can be reduced in combination with the adoption of the full-screw PC steel rod.

(3) The self-propelled mold eliminates the need for assembling and disassembling the inner and outer molds and the inner and outer scaffolds, thereby saving labor and speeding up.

(4) Due to the combination of the above-mentioned total screw PC steel rod / high-strength concrete and the self-elevating formwork method, it is possible to surely save labor in high piers compared with the conventional RC pier construction method.
The work period can be shortened and the cost can be reduced.

(5) Since the self-elevating formwork method that rises intermittently is adopted, the finish of the concrete surface is better than that of the slipform method.

(6) When an intermediate partition wall for torsional reinforcement is required in the middle portion of the pier body, there is an advantage that the inner and outer molds can be used as they are as frame support work.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a high pier according to the present invention.

FIG. 2 is a cross-sectional view of a pier, (a) showing the present invention, and (b) showing a conventional RC method.

FIG. 3 (a) is a side view showing a joint of a full-screw PC steel rod,
(b) is a perspective view showing a block example of a full-screw PC steel rod.

FIG. 4 is a perspective view showing a block example of a stirrup.

FIG. 5 (a) is a front view showing a climbing form,
(b) is a side view.

FIG. 6 is a schematic side view showing a procedure of a bridge pier construction method according to the present invention.

[Explanation of symbols]

 1 ... Bridge main body 2 ... Total screw PC steel rod 3 ... Stirrup 4 ... Embedded inner formwork 5 ... High-strength concrete A ... Steel block B ... Reinforcing bar block 6 ... Coupler 7 ... Nut 8 ... Steel suspension frame 9 ... Nut 10 ... Connection cord 20 ... Climbing form 21 ... Inner support frame 22 ... Outer support frame 23 ... Inner formwork 24 ... Outer formwork 25 ... Temporary buried steel frame 26 ... Upper suspension structure stand 27 ... Suspended wire rope 28 ... Lift jack 30 ... Foundation Concrete 31 ... Total scaffolding 32 ... Bridge pier base 33 ... Tower crane

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kumiko Suda 2-19-1, Tobita-cho, Chofu-shi, Tokyo Kashima Construction Co., Ltd. Technical Research Institute (72) Inventor Kikuo Koseki 1-2-7 Moto-Akasaka, Minato-ku, Tokyo No. Kashima Construction Co., Ltd. (72) Inventor Akio Yamauchi 1-2-7 Moto Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (72) Inventor Kazuyuki Abe 1-2-2 Moto-Akasaka, Minato-ku, Tokyo No. 7 Kashima Construction Co., Ltd.

Claims (2)

[Claims] 1. A pier, characterized in that the pier main body having a hollow cross section has an RC structure using high strength concrete with a full-screw PC steel rod as an axial streak. 2. A temporary embedded steel frame for a self-elevating formwork is installed in advance, and then a steel material block having a total screw PC steel rod along the axial direction of the pier is assembled, and inside and outside of this steel material block. Install the inner and outer molds of the self-propelled formwork, place concrete between the inner and outer formwork, assemble steel blocks, raise and install the self-propelled formwork, and place concrete. A pier construction method using the self-elevating formwork method, characterized by constructing the pier by repeating the construction in sequence.