JP2005090066A - Method of setting suspended scaffold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of setting a suspended scaffold which is for use in a survey, reinforcing work, and repairing work under a viaduct, does not require a large-scale traffic regulation on a road etc. under the viaduct, and achieves the erection of the suspended scaffold while reducing the number of post-driven anchors driven into a bridge girder. <P>SOLUTION: In the method of setting the suspended scaffold which is built under the viaduct, first a plurality of anchoring means are set in each pier (or abutment) of a bridge girder at predetermined intervals in a direction at right angles to the bridge girder, and a plurality of prestressing concrete steels (PC steel) are extended from one of the anchoring means to the other anchoring means. Then a straining means provided for one of or both of the anchoring means functions to apply a predetermined straining force to the prestressing concrete steels (PC steel), and scaffold members built up from one of the anchoring means are successively supplied to the other anchoring means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a suspension scaffold installation method for reducing traffic restrictions as much as possible when constructing a fall protection work or a construction scaffold in survey, reinforcement, and repair work under a viaduct.

  Japan's social capital has been rapidly developed in a relatively short period during the period of high economic growth. Among them, there is a bridge as a typical structure. This bridge structure is mainly composed of steel and concrete materials, but these structures are constructed with a target of 50 years of life, and the number of concrete structures that have reached the end of their useful life is gradually increasing. In addition, investigations and repair work are frequently performed due to various factors such as neutralization and deterioration of structures such as salt damage, and an increase in physical distribution that meets social needs (larger vehicles).

  Suspended scaffolding and aerial work platforms (lifts and overhangs) are the mainstreams for general scaffolding and repair work. Single-tube suspension scaffolds that can be safely constructed at low cost are expensive to construct due to large-scale traffic regulations and night construction for anchor placement on bridge girders and single pipe placement for single-tube scaffolding installation There is a problem that the bridge girder is damaged because a large number of post strike anchors are placed on the girder in order to fix the single pipe. Further, in the case of an aerial work vehicle, the number of workers is limited and the work area is reduced, so that the work efficiency is lowered and the work period is increased and the work is expensive.

  In addition, there is a method to install a large-scale mobile scaffolding such as a traveler on the main line. However, it is necessary to regulate the main road, and a large load (10 tons by concentrated load) is applied to the railing and overhanging part of the design. There is a problem that can not be. In addition, there is a problem that the production cost of the large mobile scaffold becomes high.

For this reason, a relatively inexpensive wire bridge system has been put into practical use without requiring large-scale traffic regulation. In this method, anchor metal fittings are installed on the bridge piers (or abutments) at both ends, and a plurality of messenger wires are extended below the bridge girder to fix both ends to each anchor metal fitting. On the messenger wire, a single pipe or the like called rolling is arranged at a predetermined interval in a direction perpendicular to the bridge girder. And it is the method of arranging a scaffold board on rolling and ensuring a channel | path. Naturally, a safety net for preventing the fall is installed in the rolling part. This method eliminates the need for large-scale traffic regulation, but because the messenger wire bends greatly in the center, it can interfere with passing vehicles under the bridge girder, and the gap between the girder and the work floor in the center. The problem will be that it will become difficult to investigate and repair. For this reason, in order to keep the distance between the bridge girder and the work floor constant, a method is used in which anchors are installed on the girder and the messenger wire is suspended and fixed with a hanging bracket. In addition, there are problems in that a large number of post-fixed anchors are required and suspension metal fittings hinder the efficiency of investigation and repair work. In order to reduce the deflection of the messenger wire, a method has been proposed in which tension is applied to the bridge pier with a winder using a winch or the like. However, a large tension cannot be expected in the messenger wire itself. In the case of long, there is a problem that there is not much effect.
JP-A-6-185020

  The problem to be solved is that large-scale traffic regulation is required on the lower road in the investigation and repair work under the viaduct, and a large number of rear anchors are required on the bridge girder body to construct the suspension scaffold And the work environment is bad.

  In the present invention, fixing means are provided at both piers (or abutments), the PC steel is tensioned below the bridge girder, traffic restrictions on the roads below are minimized, and the PC steel is bent by the large tension of the PC steel. The main focus is to reduce suspension costs and to reduce the cost of erection.

  The suspension scaffold installation method of the present invention can suppress the bending of the central part of the bridge girder as much as possible by giving a certain tension to a plurality of PC steel members fixed to both bridge piers (or abutment parts) of the bridge girder. For this reason, the number of suspension brackets for supporting the PC steel material from the bridge girder is very small, damage to the bridge girder is small, and workability is improved. In addition, the road regulation under the bridge girder is only at the time of installation and removal of PC steel, and there is an advantage that a suspension scaffold with less construction pollution can be provided.

  For the purpose of keeping the distance between the bridge girders constant with PC steel with high tensile strength between both piers (abutments), we realized an efficient workability and a method of installing a suspension scaffold that reduced damage to the bridge girder body. .

    FIG. 1 is an overall view illustrating a method for installing a suspended scaffold according to the present invention. Fixing means 7 is installed on the front surface of both abutments 2 of the bridge girder 1 with a certain distance from the lower end of the bridge girder 1. A plurality of fixing means 7 are fixed to the abutment 2 at a predetermined interval in a direction perpendicular to the bridge girder 1. The PC steel material 3 is passed from one fixing means 7 to the other fixing means 7, and tension is applied to the PC steel material 3 at either fixing means 7 portion. And the clamp part with a pulley which is the scaffolding material 4 is assembled and sent out from either fixing means 7 side. In the process of sending out the scaffold material 4, the hanging bracket 6 is installed from the bridge girder at a predetermined interval, and the distance from the bridge girder is made constant. At this time, the scaffolding plate 5 serving as a work floor is also disposed at the same time.

  2 to 4 are explanatory views showing the installation procedure of the suspension scaffold according to the present invention. A frame scaffolding 8 is installed in front of both abutments 2 and a post anchor 9 is driven on the abutment 2 at a certain distance from the lower end of the bridge girder 1. The number of post-hit anchors 9 is changed according to the width of the bridge girder 1 so that the entire width of the bridge girder 1 can be investigated and repaired. When the installation of the post strike anchor 9 is completed, the fixing means 7 is fixed to the wall surface of the abutment 2 with the post strike anchor 9. (Figure 2)

  A pulley 11 is installed on an adjacent framework scaffold 8 below the fixing means 7, and a messenger wire 10 is passed from the pulley through the fixing means 7 through the fixing means 7 and the other fixing means 7 and the pulley 11 from the ground (not shown). ). The PC steel material 3 is connected to the rear end portion of the messenger wire 10, and the PC steel material 3 is expanded below the bridge girder by winding the messenger wire 10 with a winder. (Figure 3)

  When the extension of the PC steel material 3 to the fixing means 7 on both sides is completed, a predetermined tension force is applied to the PC steel material 3 by the tension means installed in one of the fixing means 7 and the fixing means 7 fixes the PC steel material 3. When the tension of the PC steel material 3 is completed, the scaffolding material 4 in which the rolls that are single tubes and the clamps with pulleys are assembled is sent out from either one of the frame scaffolds 8. On the scaffold material 4, a scaffold plate 5 serving as a work floor is also installed. In the process of sending out the scaffolding material 4, the lower part of the bridge girder 1 and the scaffolding material 4 are tightly supported by the hanging metal fittings 6, and installed in the direction of the bridge girder 1 at a predetermined interval. (Fig. 4)

  Along with the installation of the scaffolding material 4 and the suspension bracket 6, a safety net is installed on the entire surface of the scaffolding material 4 to prevent the fall. The suspension scaffold dismantling method may be performed by performing the reverse operation of the installation method described above.

  FIG. 5 is an explanatory view showing the fastening means in the fixing means 7. The fixing means 7 is fixed by a post-hit anchor 9. A plate 14 provided with a through hole through which the PC steel material 3 passes is attached to the front portion of the fixing means 7. Behind the plate 14, a tension jack 12, which is a tension means that gives tension to the PC steel material 3, is installed. The PC steel material 3 passes through the through hole of the plate 14 from the central portion of the tension jack 12 main body, passes through the lower part of the bridge girder 1, enters the through hole of the fixing means 7 of the other bridge pier 2, and is fixed to the plate by the fixing tool 13. . The tension | tensile_strength of PC steel materials gives tension | tensile_strength to PC steel materials 3 by fixing the head of the tension | tensile_strength jack 12 with the fixing tool 13, and extending | stretching the tension | tensile_strength jack 12. FIG. When a predetermined tension force is introduced into the PC steel material 3, the fixing tool 13 behind the plate 14 is tightened to complete the prestress introduction into the PC steel material 3.

  As the PC steel material 3, it is possible to use a PC steel rod or a PC steel wire, but a wire is most suitable from PC steel which has a large tension and is easy to handle against bending.

  FIG. 6 is a cross-sectional view illustrating the hanging metal fitting in detail. The bridge girder 1 is a method of installing the hanging bracket 6 having the I girder in which no post anchor is provided on the bridge girder 1. Equipped with a roller 16 that can run on the haunch part of the lower flange of the I-girder, a moving metal fitting 15 that is manufactured so as to sandwich the lower flange of the I-girder is installed, and a hanging metal fitting 6 is attached below the metal fitting 15 to support the PC steel 3 . By this method, it is no longer necessary to provide a retrofitting anchor on the main body of the bridge girder 1 and the main body strength of the bridge girder 1 is not reduced.

  In the present embodiment, the method for installing the suspension scaffold in the investigation and repair work is disclosed. However, the method for installing the suspension scaffold can also be applied to the new construction.

  There are few traffic regulations for surveys and repair work under the viaduct, and it can be applied to surveys on viaducts that cross ordinary roads and railways, and to install suspension scaffolds for repair work.

It is a general view explaining the installation method of the suspension scaffold of this invention. It is explanatory drawing which shows the installation procedure of the suspension scaffold of this invention. It is explanatory drawing which shows the installation procedure of the suspension scaffold of this invention. It is explanatory drawing which shows the installation procedure of the suspension scaffold of this invention. FIG. 6 is an explanatory view showing a fastening means in the fixing means 7. It is sectional drawing explaining a hanging metal fitting in detail.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bridge girder 2 Abutment 3 PC steel material 4 Scaffolding material 5 Scaffold plate 6 Suspension metal fitting 7 Fixing means 8 Frame scaffolding 9 Post strike anchor 10 Messenger wire 11 Pulley 12 Tension jack 13 Fixing tool 14 Plate 15 Moving metal 16 Roller

Claims (1)

  In the installation method of the suspension scaffold assembled under the bridge, a plurality of fixing means are installed at predetermined intervals in the direction perpendicular to the bridge girder on both piers (or abutments) of the bridge girder. Scaffold assembled from either side of fixing means by delivering a plurality of PC steel materials to fixing means, applying a certain tension to the plurality of PC steel materials by means of tensioning means provided on one or both of the fixing means A method for installing a suspension scaffold, wherein the material is sent to the other fixing means side.

Images