JP2021001476A - Concrete member fall prevention device and fall prevention method - Google Patents

Abstract

To provide concrete member fall prevention device and fall prevention method, for preventing a PCa segment T girder from falling to enable safe conveyance, building, or the like of the PCa segment T girder.SOLUTION: A concrete member fall prevention device is constituted by: a fall prevention support 2 that is to be erected at a side of a main girder part A1 of a PCa segment T girder A to support a flange part A2 of the PCa segment T girder A upward; and a fixation bracket 3 that is to be fitted on a side surface part of the main girder part A1 to fix the fall prevention support 2 at the side of the main girder part A1. The fall prevention support 2 comprises a height adjustment jack 4. The fixation bracket 3 comprises an arm part 7 for connecting the fixation bracket 3 with the fall prevention support 2. The arm part 7 is installed so as to be capable of being stored on the side surface part of the main girder part A1 by horizontally revolving on the main girder part A1 side.SELECTED DRAWING: Figure 1

Description

The present invention relates to a fall prevention device and a fall prevention method for concrete members, mainly immediately after production of a precast concrete (hereinafter “PCa”) segment T girder, at the time of storage, at the time of transportation by a girder carrier, and at the time of erection at the site. This is intended to prevent the PCa segment T girder from tipping over (sideways) so that the PCa segment T girder can be safely transported and erected.

In new construction of bridges such as road bridges, PCaT girders consisting of a main girder and a flange formed at the upper end of the main girder are generally used, especially when it is too long and difficult to transport. The PCa segment T digit is used.

In addition, this type of PCaT girder is mainly produced in a factory, then transported to the site and erected at a predetermined erection position at the site.

By the way, in general, PCaT girders are formed in an unstable vertically long T-shaped cross-sectional shape and have a considerable weight. Therefore, immediately after dismantling the formwork in the manufacturing process, when transporting by a girder carrier, or even on site. At the time of erection, measures will be taken to prevent the vehicle from tipping over.

For example, when erection of a PCaT girder brought into the site between bridges, the PCaT girder is lifted by a crane or the like and installed in a predetermined position, and then the PCaT girder is suspended and pipe supports, logs, etc. are placed on both sides of the PCaT girder. Install a cheek-type fall prevention material consisting of.

Furthermore, measures are taken to prevent falls, such as installing anti-tilt structures between adjacent PCaT girders and connecting adjacent PCaT girders to support them from tipping over until the installation of the PCaT girders is completed.

Further, Patent Document 1 (see FIG. 10) discloses a method for preventing the box culvert from tipping over. Briefly, on both sides of the box culvert installed on the installation stand, support frames made by assembling rod-shaped support members in a truss shape with a wide lower part and a taper toward the upper part are temporarily installed. Supports the box culvert from both sides to prevent it from tipping over.

JP-A-2018-178668

However, for the cheek cane type fall prevention material and anti-tilt structure, it is necessary to consider the mounting position and dimensions for each girder according to the size and installation location of the PCaT girder, and it is mounted every time the PCaT girder is moved. It was very troublesome to handle because of the removal work.

Further, in the fall prevention method of the box culvert as shown in Patent Document 1, since the weight of the box culvert reaches several tons to several tens of tons, it is necessary to make the support frame strong and large-scale. It takes a lot of time and effort to attach and remove the support frame, which imposes a heavy burden on the operator and raises the work cost.

Furthermore, with the fall prevention measures so far, there may be a situation where no fall prevention measures are installed immediately after the production of the PCaT girder (before moving from the production line) until the completion of the installation at the site. Therefore, it is not always perfect as a safe fall prevention measure for the PCaT girder.

The present invention has been made to solve the above problems, and is mainly transported to the site immediately after the production of concrete members such as PCaT girders (before moving from the production line) until the installation at the site is completed. It is an object of the present invention to provide a fall prevention device and a fall prevention method for concrete members, which can prevent the concrete members from toppling over and safely carry out transportation, erection, etc. of the PCa segment T girder.

The present invention is an invention of a fall prevention device for a concrete member, which is arranged on both sides of a concrete member including a main girder portion and a flange portion provided at an upper end portion of the main girder portion to prevent the concrete member from falling sideways. A fall prevention support that is erected on both sides of the main girder portion of the concrete member and supports the flange portion upward, and a fall prevention support that is attached to the side surface portion of the main girder portion to provide the fall prevention support to the main girder. The fixing bracket is provided to be fixed to the side surface portion of the portion, the fall prevention support is provided with a height adjusting jack, the fixing bracket is provided with an arm portion for fixing the fall prevention support to the main girder portion of the concrete member, and the above-mentioned The arm portion is characterized in that it is installed so as to be retractable in the axial direction of the main girder portion along the side surface portion of the main girder portion by rotating horizontally about the main girder portion side.

The present invention is mainly used to prevent the PCa segment T girder from tipping over, and is used by a girder carrier immediately after the production of the PCa segment T girder, that is, immediately after the completion of the mold dismantling work in the manufacturing process of the PCa segment T girder, and during loading. Prevents the PCa segment T girder from tipping over (sideways) at each installation position during transportation and until the PCa segment T girder is erected locally, so that the PCa segment T girder can be transported, stored, and erected. It is designed to be carried out safely.

In principle, two fall prevention devices of the present invention are used as a set, and are installed at symmetrical positions on both sides of the PCa segment T girder at the same time as the formwork dismantling work in the manufacturing process of the PCa segment T girder is completed. ..

At that time, it is desirable to install at least one or a plurality of sets at both ends of the T girder of the PCa segment in the longitudinal direction, and to install them in the intermediate portion as necessary.

Further, the fixing bracket can be detachably attached by using a plurality of mounting bolts (steel rods), mounting nuts, etc. by using the lateral tightening holes formed on the side portion of the PCa segment T girder.

The fall prevention support is provided when installing the fixing bracket at the same time as the completion of the mold dismantling work of the PCa segment T girder, when transporting the PCa segment T girder on the girder carrier, and when the PCa segment T girder is erected on site. Each time it is erected on the PCa segment T girder, it is erected on both sides of the PCa segment T girder and fixed to the main girder portion of the PCa segment T girder by the fixing bracket.

Then, by vertically adjusting the PCa segment with the height adjustment jack, the PCa segment T girder is supported so as not to tip over at each installation position from immediately after the production of the PCa segment T girder to the completion of the on-site erection. be able to.

In addition, when the PCa segment T girder is hung from the production line by a crane or the like, when loading and unloading on a girder carrier, and when the PCa segment T girder is installed at the erection position on site, the above-mentioned fall prevention The support is removed, and the arm portion of the fixing bracket is stored in the axial direction of the PCa segment T girder along the side surface portion of the main girder portion by rotating horizontally around the main girder portion side of the PCa segment T girder. ..

The fixed bracket has an arm portion that extends like a cantilever toward the fall prevention support side, and an arm that is stored in the axial direction of the main girder portion along the side surface of the main girder portion of the PCa segment T girder. By providing a rotation stop stopper that fixes the part so that it does not rotate, the fall prevention support 2 may shift or come off from the installed position due to impact, and the main girder part may be transferred during the transfer of the PCa segment T girder. It is possible to prevent the connecting portion stored in the side surface portion of the above from dangling.

For the fall prevention support, a steel pipe support equipped with a screw-type jack, which is widely used at civil engineering and construction sites, can be used.

According to the present invention, immediately after the production of the concrete member, that is, at the same time when the mold dismantling work in the manufacturing process of the concrete member is completed, fixing brackets are attached to both side surfaces of the concrete member, and immediately after the concrete member is dismantled, the concrete member is attached. When transporting by mounting on a girder carrier, and when erection at an erection position on site, a fall prevention support is installed on both sides of the concrete member, and the main girder portion of the concrete member is provided via the fixing bracket. By fixing the concrete member to the concrete and vertically adjusting the concrete member with a height adjusting jack, it is possible to reliably prevent the concrete member from tipping over from immediately after the production of the concrete member to the completion of erection at the site.

In addition, when the concrete member is suspended and moved by a crane or the like, the concrete member can be safely transferred by removing the fall prevention support and storing the fixing bracket along the side surface of the main girder. ..

An embodiment of the present invention is illustrated, FIG. (A) is a perspective view showing a PCa segment T girder and a fall prevention device installed on a side thereof, and FIG. (B) is a PCa segment T girder. It is a perspective view which shows the fixing bracket. The PCa segment T girder and the fall prevention devices installed on both sides thereof are shown. FIG. (A) is a vertical sectional view, and FIG. (B) is a perspective view of a fall prevention support. The operation of the arm portion of the fixed bracket is illustrated, and is an enlarged cross-sectional view taken along the line E in FIG. 2 (a). A modified example of the fall prevention device is illustrated. FIG. (A) is a vertical sectional view showing the PCa segment T girder and the fall prevention devices installed on both sides thereof, and FIG. 4 (b) is FIG. 4 (a). ) Is a cross-sectional view taken along the line. FIG. (A) is an enlarged view of part C in FIG. 4 (a), and FIG. (B) is a two-two cross-sectional view in FIG. 5 (a).

1 and 2 show an embodiment of the present invention, in which a concrete member (hereinafter referred to as “PCa segment T girder”) A is attached to a concrete member fall prevention device for preventing the PCa segment T girder A from tipping over. (Hereinafter, "fall prevention device") 1 is installed in plurality.

The PCa segment T girder A includes a main girder portion A ₁ and a flange portion A ₂ formed at the upper end portion of the main girder portion A ₁ , and is formed as a whole having a substantially T-shaped cross section.

The fall prevention device 1 is a set of two and is installed substantially symmetrically on both sides of the main girder portion A ₁ of the PCa segment T girder A, and is installed on both sides of at least both ends in the longitudinal direction, and in particular, When the beam formation (height) of the PCa segment T girder A is large and extremely unstable, it is also installed on both sides of the intermediate portion as needed.

Each fall prevention device 1 is installed on the lower side of the flange portion A ₂ of the PCa segment T girder A and rises from the floor surface, and the fall prevention support 2 and the side surface portion of the main girder portion A ₁ of the PCa segment T girder A. attached to, and a fixing bracket 3 to fix the anti-tip support 2 on the side surface of the main girder portion a _1.

The fall prevention support 2 is provided with height adjusting jacks 4 at both upper and lower ends or one of them, and the height adjusting jack 4 can vertically adjust the PCa segment T girder A and the height of the PCa segment T girder A. The height (level) can be adjusted freely.

For the fall prevention support 2, a steel pipe support or the like equipped with a screw-type jack widely used at civil engineering and construction sites is used.

The fixing bracket 3 has a fixing portion 5 fixed to the side surface portion of the main girder portion A ₁ of the PCa segment T girder A, and the fixing portion 5 is pivotally supported by the fixing portion 5 so as to be rotatable in the horizontal direction around the rotary rod 6 and falls. It is provided with an arm portion 7 that vertically supports the prevention support 2.

The fixing unit 5, the main girder is formed in a predetermined length in the vertical direction along the side of A _1, and desorbed by a nut 9 mounted with a plurality of mounting bolts (steel rod) 8 on the side surface of the main girder portion A ₁ It is fixed as possible.

At that time, the lateral tightening hole a formed on the side portion of the main girder portion A ₁ can be used as the bolt hole of the mounting bolt 8. The lateral tightening hole a is a lateral hole formed by horizontally penetrating the side portion of the main girder portion A ₁ , and a plurality of PCa segments T girders A arranged in parallel in the same direction are aligned in the direction perpendicular to the axis. It is a connecting hole through which steel rods for connecting to each other are inserted.

The arm portion 7 is formed in the shape of a truss beam from a plurality of steel rods (reinforcing bars, etc.) or a single pipe in order to reduce the weight, and the fall prevention support 2 is formed by turning the rotating rod 6 in the horizontal direction. extending cantilevered in a direction (see FIG. 1 (a)), and can be stored along the side of the main girder portion a ₁ in the axial direction of the PCa segment T digit a is installed (see FIG. 1 (b)) ing.

Further, a grip portion 10 for gripping the fall prevention support 2 detachably from the side is attached to the tip end portion of the arm portion 7.

The grip portion 10 is configured in a ring shape that allows the fall prevention support 2 to be gripped from both sides by, for example, a set of arc-shaped members, and the other end side opens and closes and falls by rotating horizontally around the connected side. The prevention support 2 is gripped from the side, and the other end side is fastened with the tightening bolt 11 so that the fall prevention support 2 can be gripped detachably (see FIG. 3).

In such a configuration, in order to prevent the PCa segment T girder A from falling sideways by using the fall prevention device 1, the formwork dismantling work is completed in the manufacturing process of the PCa segment T girder A, and at the same time, the main girder portion A ₁ The fixing brackets 3 are attached to the side surfaces on both sides of the.

Further, each time the fixing bracket 3 is attached to the main girder portion A ₁ , the PCa segment T girder A is mounted on the girder carrier and transported, and the PCa segment T girder A is erected on site, the PCa segment T Fall prevention supports 2 are erected on both sides of the girder A, and are fixed to the main girder A ₁ of the PCa segment T girder A via the fixing bracket 3.

In addition, by vertically adjusting the PCa segment T girder A with the height adjustment jack 4 of each fall prevention support 2, each installation from immediately after the production of the PCa segment T girder A to the completion of the on-site erection. It is possible to reliably prevent the PCa segment T girder A from tipping over at the position.

In addition, when the PCa segment T girder A is carried out from the production line, or when the PCa segment T girder A is suspended by a crane or the like for loading and unloading on a girder carrier, the fall prevention support 2 the well as removal, by storing the fixed bracket 3 in a state along the side portion of the main girder portion a ₁ (see FIG. 1 (b)), it is possible to move the PCa segment T digits a very safe.

The fixing portion 5 of the fixing bracket 3 includes an arm portion 7 extending like a cantilever toward the fall prevention support 2 side and an arm portion 7 stored on the side surface of the main girder portion A ₁ , respectively. A rotation stopper (not shown) is attached to fix it so that it does not rotate.

As a result, the fall prevention support 2 installed on the side of the PCa segment A may shift or come off from the installation position due to an impact, and the main girder part A ₁ may be transferred during the transfer of the PCa segment T girder A. It is possible to prevent the arm portion 7 stored in the side surface portion of the above from dangling.

4 and 5 show a modified example of the fall prevention device of the present invention. In particular, the arm portions 7 of the fixing bracket 3 are vertically spaced apart from each other at regular intervals 7a. , 7a, with vertical frame members 7b, 7b erected vertically between both ends of the upper and lower horizontal frame members 7a, 7a, and intermediate frame members 7c installed horizontally in the middle of the vertical frame members 7b, 7b. , It is configured in a vertically long rectangular frame.

Further, the rotating pins 12 and 12 are vertically attached to the ends of the upper and lower horizontal frame members 7a and 7a on the fixing portion 5 side, and the rotating pins 12 and 12 can be rotated horizontally around the rotating pins 12 and 12 at both upper and lower ends of the fixing portion 5. It is attached to.

The vertical rotation pins 12 and 12 are detachably inserted from directly above into the pin receiving holes 13 and 13 vertically formed at both upper and lower ends of the fixing portion 5, whereby the arm portion 7 is mainly inserted. It is connected to the fixing portion 5 attached to the side surface portion of the girder portion A ₁ and can be removed from the fixing portion 5.

Further, a grip portion 10 for detachably gripping the fall prevention support 2 is attached to an end portion of the upper and lower horizontal frame members 7a, 7a on the fall prevention support 2 side. The grip portion 10 is exactly the same as that described in FIG.

Further, it is stored in the fixing portion 5 along the side surfaces of the arm portion 7 and the main girder portion A _{1 in} a state where the rotating pins 12 and 12 are horizontally swiveled around the axis and extended in a cantilever shape toward the fall prevention support 2. A rotation stopper 14 is attached to fix the arm portion 7 in the folded state so as not to rotate.

Thus, anti-tip support 2 attached upright on the side of PCa segment A, that or deviate shocked, such as during transport of PCa segment T digits A, a side surface portion of the main girder portion A ₁ The stored arm portion 7 does not dangle.

According to the present invention, the PCaT girder falls at each installation position immediately after production of the PCa segment T girder (before moving from the production line), during storage, during transportation by a girder carrier, and when the PCaT girder is erected on site. It is possible to safely carry out storage, transportation, erection, etc. of PCaT girders.

A PCa segment T girder (concrete member)
A ₁ Main girder part A ₂ Flange part 1 Fall prevention device 2 Fall prevention support 3 Fixing bracket 4 Height adjustment jack 5 Fixing part 6 Rotating rod 7 Arm part 8 Mounting bolt (steel rod)
9 Mounting nut
10 Grip
11 Tightening bolt
12 rotating pins
13 Pin receiving hole
14 Pin

Claims (3)

A fall prevention device for a concrete member that is arranged on both sides of a concrete member having a main girder portion and a flange portion provided at the upper end portion of the main girder portion to prevent the concrete member from falling sideways. A fall prevention support that is erected on the side of the main girder portion of the concrete member and supports the flange portion upward, and a fall prevention support that is attached to the side surface portion of the main girder portion and provides the fall prevention support to the side portion of the main girder portion. The fall prevention support is provided with a height adjusting jack, the fixing bracket is provided with an arm portion for fixing the fall prevention support to the main girder portion of the concrete member, and the arm portion is provided with a fixing bracket. A fall prevention device for a concrete member, which is horizontally rotated about the main girder side and is storably installed on a side surface of the main girder. A concrete member having a main girder portion and a flange portion provided at the upper end portion of the main girder portion, and a plurality of concrete members arranged on both side portions of the concrete member to prevent the concrete member from falling sideways. A concrete member with a fall prevention device provided with a device, wherein the fall prevention device is erected on a side portion of a main girder portion of the concrete member, and has a fall prevention support that supports the flange portion upward. The fall prevention support is provided with a fixing bracket attached to the side surface portion of the main girder portion and fixing the fall prevention support to the side portion of the main girder portion, the fall prevention support is provided with a height adjusting jack, and the fixing bracket is said to fall. An arm portion for fixing the prevention support to the main girder portion of the concrete member is provided, and the arm portion is installed so as to be storable on the side surface portion of the main girder portion by rotating horizontally about the main girder portion side. A concrete member with a fall prevention device, which is characterized by being present. A method for preventing a concrete member from toppling over, which comprises the following steps in the method for preventing the concrete member from toppling over by using the anti-falling device for the concrete member according to claim 1.
(1) A step of attaching the fixing brackets to both side surfaces of the concrete member after the formwork dismantling work in the manufacturing process of the concrete member is completed.
(2) A step of erection of the fall prevention support on both sides of the main girder portion of the concrete member to support the flange portion of the concrete member upward.
(3) A step of fixing the fall prevention support to the side portion of the concrete member via the arm portion of the fixing bracket.
(4) A step of vertically adjusting the concrete member by the height adjusting jack.

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