JP2021001475A - 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 PCaT girder from falling at the time of conveyance, building, or the like of the PCaT girder to enable safe conveyance, building, or the like of the PCaT girder.SOLUTION: A plurality of fall prevention devices 1 are symmetrically disposed on both side surface parts of a PCaT girder A. Each fall prevention device 1 is constituted by: a fall prevention support 2 to be fitted on a side surface part of the PCaT girder A; and a height adjustment jack 3 that is fitted on a lower end of the fall prevention support 2 to adjust the PCaT girder A at an installation position so as to be vertical.The fall prevention support 2 is constituted by: a fitting part 2a that is formed in the vertical direction along a side surface of the PCaT girder A and is to be fixed on the side surface of the PCaT girder A; an arm part 2b formed on a lateral side of the PCaT girder A from a lower end of the fitting part 2a; and a leg part 2b formed downward from a tip of the arm part 2b.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 referred to as “PCa”) 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 girder from tipping over (sideways) so that the PCaT girder can be safely transported and erected.

In new construction of bridges such as road bridges, a PCaT girder consisting of a main girder and a flange formed at the upper end of the main girder is generally 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 abutments, 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.

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 carried from immediately after the production of concrete members such as PCaT girders (before moving from the production line) to the site until the installation at the site is completed. In the meantime, 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 and erection of the concrete members.

The present invention is an invention of a fall prevention device for a concrete member which is arranged on both side portions of a concrete member and prevents the concrete member from falling sideways. A fall prevention support attached to a side surface portion of the concrete member and the fall prevention. It is equipped with a height adjusting jack that is attached to the lower end of the support and vertically adjusts the concrete member, and the fall prevention support is formed in the vertical direction along the side surface of the concrete member and is formed on the side surface portion of the concrete member. It is characterized by including a mounting portion to be fixed, an arm portion formed on the side of the concrete member from the mounting portion, and a leg portion formed downward from the tip end portion of the arm portion. Is.

The fall prevention device for concrete members of the present invention is mainly used to prevent the PCaT girder from toppling over, and is used for storing the girder immediately after the production of the PCaT girder, that is, immediately after the completion of the formwork dismantling work in the manufacturing process of the PCaT girder. To prevent the PCaT girder from tipping over (sideways) at each installation position until the time of transportation by the PCaT girder and the time of erection of the PCaT girder at the site, so that the transportation, storage and erection of the PCaT girder can be carried out safely. It is the one that was made.

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 PCaT girder at the same time as the formwork dismantling work in the manufacturing process of the PCaT girder is completed.

At that time, it is desirable to install at least one or a plurality of sets at both ends of the PCaT girder in the longitudinal direction, and to install them in the middle as necessary. In addition, each fall prevention device can be detachably attached by bolts, nuts, or the like using the lateral tightening holes formed on the side of the PCaT girder.

Then, by vertically adjusting the PCaT girder at each installation position at each installation position at the time of dismantling the formwork of the PCaT girder, at the time of loading, at the time of transportation by the girder carrier, and at the time of erection at the site, the PCaT girder is vertically adjusted by the height adjustment jack. It is possible to support the PCaT girder at each installation position from immediately after the production to the completion of the on-site installation so as not to tip over.

In addition, when unloading the PCaT girder from the production line, loading and unloading it on the girder carrier, and installing it at the erection position on site, it is hung by a crane or the like with the fall prevention device attached. be able to.

According to the present invention, immediately after the production of the concrete member, that is, at the same time when the formwork dismantling work in the manufacturing process of the concrete member is completed, the concrete member is attached to both sides of the concrete member, and immediately after the formwork is disassembled and stored. By vertically adjusting the concrete members at each installation position at the time of transportation by the girder carrier and at the time of erection on site with the height adjustment jack, it is possible to prevent the concrete members from tipping over and to safely transport and erection the concrete members. It can be carried out. Further, when the concrete member is suspended and moved by a crane or the like, the concrete member can be moved while being attached to the concrete member.

An embodiment of the present invention is illustrated, and is a front view of a fall prevention device for concrete members attached to both sides of a PCaT girder. It is a perspective view which shows the fall prevention device of a set of concrete members. FIG. (A) is a side view of a fall prevention device for a concrete member, and FIG. (B) is a cross-sectional view taken along the line in FIG.

1 to 3 show an embodiment of the present invention, in which a concrete member (hereinafter referred to as “PCaT girder”) A has a concrete member fall prevention device (hereinafter referred to as “falling over”) that prevents the PCaT girder A from tipping over. A plurality of "prevention devices") 1 are attached. Incidentally, pcat digit A, the main girder portion A ₁ and the main girder portion and a flange portion A ₂ formed on the upper end of A _1, generally in the form of a vertically elongated cross section T-shaped.

The fall prevention device 1 is a set of two and is symmetrically attached to both side surfaces of at least both ends of the PCaT girder A in the longitudinal direction. In particular, the beam formation (height) of the PCaT girder is large and extremely unstable. In such cases, it will be installed on both sides of the middle part as needed.

Each fall prevention device 1 includes a fall prevention support 2 and a height adjusting jack 3 attached to the lower end of the fall prevention support 2.

The fall prevention support 2 has a mounting portion 2a formed vertically along the side surface of the PCaT girder A for a predetermined length, and a predetermined length continuous from the lower end portion of the mounting portion 2a to the side of the PCaT girder A. The formed arm 2b and the leg portion 2c formed continuously for a predetermined length downward from the tip portion of the arm portion 2b are provided, and the mounting portion 2a, the arm portion 2b, and the leg portion 2c have a substantially groove shape in cross section. It is formed and is continuously formed integrally.

Further, the lengths of the mounting portions 2a, the arm portions 2b, and the leg portions 2c are formed to the optimum lengths according to the beam formation (height) of the PCaT girder A, for example, the mounting portions 2a and the arm portions. Since the 2b is formed to be slightly longer and the arm portion 2b is formed to be slightly inclined downward, the PCa T girder A can be supported more stably from both sides. Further, if the mounting portion 2a, the arm portion 2b, and the leg portion 2c are formed in a pipe having a continuous rectangular cross section, the strength of the fall prevention support 2 is further increased.

Further, if the arm portion 2b and the leg portion 2c are configured so that the length can be adjusted by adopting a double pipe structure that can slide in the pipe axis direction from the outer pipe and the inner pipe, the size of the PCaT girder A is large. Stability can be improved by adjusting the length accordingly.

A plurality of mounting holes 2d are formed in the mounting portion 2a at intervals in the longitudinal direction (vertical direction) of the mounting portion 2a, and an end plate 2e is mounted on the lower end portion of the leg portion 2c. A bolt through hole 2f is formed in the center of the end plate 2e.

The height adjustment jack 3 is screwed into the height adjustment nut 3a attached to the center of the lower surface of the end plate 2e and the height adjustment nut 3a, and vertically penetrates the bolt through hole 2f of the end plate 2e. The height adjusting bolt 3b to be used and the leg portion 4 attached to the lower end portion of the height adjusting bolt 3b are provided.

A long nut and a long bolt are used for the height adjusting nut 3a and the height adjusting bolt 3b, respectively.

The leg portion 4 includes a base plate 4a and a support nut 4b attached to the center of the upper surface of the base plate 4a, and the lower end portion of the height adjusting bolt 3b is screwed into the support nut 4b.

Then, by turning the height adjusting bolt 3b of each height adjusting jack 3 to adjust the height H of the fall prevention support 2 from the ground, the PCaT girder A at each installation position can be vertically installed.

Such fall prevention device 1 configured in the two and one set, at the same time the mold dismantling in the fabrication process of PCaT digit A is completed, arranged symmetrically on both side surfaces of the main girder portion A ₁ of PCaT digit A It is detachably attached by a plurality of mounting bolts (steel rods) 5 and a plurality of mounting nuts 6.

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 5.

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.

Then, immediately after the completion of the formwork dismantling work of the PCaT girder A, the PCaT girder A at each installation position is vertically adjusted by the height adjustment jack 4 at the time of loading, transporting by the girder carrier, and erection at the site. Therefore, it is possible to prevent the PCa T digit A from tipping over.

Further, when the PCaT girder A is carried out from the production line and the PCaT girder A is suspended by a crane or the like and moved, the fall prevention device 1 can be moved while being attached to the PCaT girder A.

The present invention prevents the PCaT girder from tipping over (sideways) immediately after production of concrete members such as PCaT girders (before moving from the production line), during storage, during transportation by a girder carrier, and during on-site erection. As a result, PCaT girders can be safely stored, transported, and erected.

A PCa T girder (concrete member)
A ₁ Main girder part A ₂ Flange part 1 Fall prevention device (fall prevention device for concrete members)
2 Fall prevention support
2a mounting part
2b arm
2c legs
2d mounting holes
2e End plate 3 Height adjustment jack
3a Adjusting nut
3b long bolt 4 legs
4a base plate
4b Support nut 5 Mounting bolt (steel rod)
6 Mounting nut

Claims (5)

A fall prevention device for a concrete member that is arranged on both sides of the concrete member and prevents the concrete member from falling sideways, and is attached to a fall prevention support attached to a side surface portion of the concrete member and a lower end portion of the fall prevention support. A mounting portion that is mounted and includes a height adjusting jack that vertically adjusts the concrete member, the fall prevention support is formed in the vertical direction along the side surface of the concrete member, and is fixed to the side surface portion of the concrete member. A fall prevention device for a concrete member, which comprises an arm portion formed on the side of the concrete member from the mounting portion and a leg portion formed downward from the tip end portion of the arm portion. .. The fall prevention device for a concrete member according to claim 1, wherein the mounting portion is detachably fixed by a plurality of steel rods protruding from a lateral tightening hole formed on a side portion of the concrete member. A fall prevention device for concrete members. A concrete member with a fall prevention device, which is composed of a concrete member and a plurality of fall prevention devices arranged on both sides of the concrete member to prevent the concrete member from falling. The fall prevention device is the concrete member of the concrete member. It is equipped with a fall prevention support attached to both side surfaces and a height adjustment jack attached to the lower end of the fall prevention support to vertically adjust the concrete member, and the fall prevention support is attached to the side surface of the concrete member. A mounting portion formed in the vertical direction along the concrete member and fixed to the side surface portion of the concrete member, an arm portion formed on the side of the concrete member from the mounting portion, and a lower portion from the tip portion of the arm portion. A concrete member with a fall prevention device, which is characterized by having a provided leg. A method for preventing a concrete member from toppling over, which comprises the following steps in the method for preventing a concrete member from toppling over by the anti-falling device for the concrete member according to claim 1 or 2.
(1) A step of attaching the fall prevention device 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 vertically adjusting the concrete member by the height adjustment jack. In the method for preventing the concrete member from tipping over according to claim 4, at the same time as the formwork dismantling work in the manufacturing process of the concrete member is completed, when the concrete member is stored, when the concrete member is transported by a transport vehicle, and when the concrete member is erected. A method for preventing a concrete member from tipping over, which comprises a step of vertically adjusting the concrete member by the height adjusting jack.

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