Precast floor-slab height adjustment mechanism and precast floor-slab height adjustment jig

Abstract

To provide a mechanism for adjusting the height of a precast floor slab and a jig for adjusting the height of the precast floor slab, which improve working efficiency and durability.SOLUTION: The height adjusting device includes an insert 7 provided on a side 1a of the precast floor slab 1, a height adjusting fitting 20 detachably provided on the insert, and a height adjusting bolt 10 for adjusting the height of the precast floor slab with respect to a reference surface 5a, and the height of the precast floor slab with respect to the reference surface can be adjusted by adjusting an insertion length L1 of the height adjusting bolt with respect to the height adjusting fitting.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a precast deck height adjustment mechanism and a precast deck height adjustment jig. [Background technology]

[0002] In bridge deck erection work, a precast deck is installed on steel girders. When installing a precast deck on a steel girder, approximately eight height-adjusting bolts are used for each precast deck. Conventionally, the height of a precast deck has generally been adjusted using a mechanism of height-adjusting fittings and height-adjusting bolts embedded in the precast deck. When the precast deck is manufactured, height-adjusting fittings and box-punching sheaths are embedded in the concrete beforehand, and height-adjusting bolts are installed in the bolt holes when the precast deck is erected (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-229818 Summary of the Invention [Problem to be solved by the invention]

[0004] After erecting the precast deck, non-shrinkage mortar is poured between the precast deck and the steel girder. After the non-shrinkage mortar hardens, the height adjustment bolts are removed and the holes are filled with non-shrinkage mortar. The height adjustment fittings are embedded in the concrete and cannot be reused. Furthermore, when erecting the precast deck, it is common to install dedicated lifting hardware inserts on the top of the precast deck, fix sling fittings to them, and lift the precast deck; these inserts also need to be buried after use.

[0005] In other words, when manufacturing the precast deck, height adjustment fittings and box punch sheaths must be installed in advance before pouring the concrete, which reduces work efficiency due to the time and effort required for installation, the cost of the parts, and the interference of the fixing parts installed when leveling the top edge of the concrete.

[0006] Additionally, multiple hardware and tools are required for the precast deck slabs, such as lifting hardware and height adjustment bolts, and workability needs to be improved.Furthermore, after the precast deck slabs are erected, the lifting inserts and height adjustment bolt holes need to be filled with non-shrink mortar, which requires labor and costs for the non-shrink mortar material.

[0007] Furthermore, precast deck slabs have prestressing steel members and reinforcing bars densely arranged, and when embedding height adjustment fittings within the precast deck slab, the placement of the prestressing steel members and reinforcing bars must be taken into consideration, which affects the degree of freedom in design considerations. Also, although a waterproof layer is installed on the top surface of the precast deck slab, this may become a route for road surface water infiltration in the future, and there is a risk that the infiltration of road surface water will affect the durability of the deck and steel girders.

[0008] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a precast deck height adjustment mechanism and a precast deck height adjustment jig that improve work efficiency and durability. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the precast deck height adjustment mechanism of the present invention comprises an insert provided on the side of the precast deck, a height adjustment fitting that is detachably attached to the insert, and a height adjustment bolt that adjusts the height of the precast deck relative to a reference surface, and is characterized in that the height of the precast deck relative to the reference surface can be adjusted by adjusting the insertion length of the height adjustment bolt into the height adjustment fitting.

[0010] According to this invention, the height of the precast deck can be adjusted using height-adjusting fittings and height-adjusting bolts that can be attached and detached to inserts provided on the side of the precast deck, eliminating the need for fittings for height adjustment on the top surface of the precast deck. Furthermore, because filler concrete is poured onto the sides of the precast deck to connect adjacent precast decks, the work of filling recesses and openings provided in the precast deck for height adjustment can be eliminated. In other words, the work efficiency of precast deck manufacturing and construction can be improved, and the durability of the precast deck itself can be improved.

[0011] In addition, the present invention may provide a height-adjustable fitting that comprises a main body portion through which the height-adjustable bolt is inserted, and an insertion portion that is connected to the main body portion and can be inserted into the insert, and only the insert may be embedded in the precast deck.

[0012] By configuring it in this manner, after the height adjustment work of the precast deck is completed, the height adjustment fittings and height adjustment bolts can be easily removed from the inserts embedded in the precast deck, allowing the filling concrete to be poured without any problems.

[0013] In the present invention, a hanging fixture may be configured to be detachably attached to the height adjustment bolt.

[0014] With this configuration, the precast deck can be easily transported by attaching the hanging hardware to the height adjustment bolt. Since there is no need to provide a separate jig or other attachment for the hanging hardware on the precast deck, the work efficiency of the precast deck manufacturing and construction can be improved.

[0015] The precast deck height adjustment jig of the present invention is characterized by comprising a height adjustment fitting and a height adjustment bolt used in the above-mentioned precast deck height adjustment mechanism.

[0016] According to this invention, by attaching and detaching the precast deck height adjustment jig to the insert provided on the side of the precast deck, it is possible to easily adjust the height of the precast deck and connect precast decks to each other. In other words, the work efficiency of manufacturing and constructing precast decks can be improved, and the durability of the precast deck itself can be improved. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a precast deck slab height adjustment mechanism and a precast deck slab height adjustment jig that improve work efficiency and durability. [Brief explanation of the drawings]

[0018] [Figure 1] This is an oblique view showing the state in which height adjustment bolts and hanging hardware are attached to the precast deck. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line BB in FIG. [Figure 4] 1A and 1B are drawings of one embodiment of a height-adjustable fitting, in which (a) is a plan view, (b) is a view taken in the direction of an arrow C in (a), and (c) is a view taken in the direction of an arrow D in (b). [Figure 5] 10A and 10B are drawings of another embodiment of a height-adjustable metal fitting, in which (a) is a plan view, (b) is a view taken in the direction of an arrow E in (a), and (c) is a view taken in the direction of an arrow F in (b). [Figure 6] FIG. 10 is a front view showing the state in which the hanging hardware is attached to the height adjustment bolt. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, a precast deck slab height adjustment mechanism and a precast deck slab height adjustment jig according to an embodiment of the present invention will be described with reference to Figs.

[0020] As shown in Figures 1 to 3, a plurality of precast slabs 1 are arranged on the top surface 5a of a steel girder 5. A bridge is constructed by arranging a plurality of precast slabs 1 continuously on the steel girder 5. The precast slab 1 has a concrete portion 2 and reinforcing bars 3 embedded in the concrete portion 2. When placing the precast slab 1 on the steel girder 5, it is necessary to adjust the precast slab 1 to a predetermined height level. A mechanism for adjusting the precast slab 1 to a predetermined height will be described.

[0021] An insert 7 is embedded in the side surface 1a of the precast deck 1. The insert 7 is a cylindrical metal member. Multiple inserts 7 are attached to the side surface 1a of the precast deck 1 at predetermined intervals. The end 7a of the insert 7 is approximately flush with the side surface 1a of the precast deck 1 and is arranged exposed on the side surface 1a. A threaded portion 9 is formed on the inner surface of the through hole 8 of the insert 7. The insert 7 is attached to both sides of the side surface 1a of the precast deck 1. Multiple inserts 7 are attached at approximately the same height on the side surface 1a of the precast deck 1. In this embodiment, four inserts 7 are attached to the side surface 1a.

[0022] A height-adjustable fitting 20 is detachably attached to the insert 7. The height-adjustable fitting 20 has a main body 21 and an insertion part 22 connected to the main body 21. The height-adjustable fitting 20 is made of metal.

[0023] 4, the main body 21 is formed in a substantially rectangular parallelepiped shape. A through hole 24 that penetrates the main body 21 in the up-down direction is formed. A threaded portion 25 is formed on the inner surface of the through hole 24.

[0024] The insertion portion 22 is integrally connected to the main body portion 21. The insertion portion 22 is a rod-shaped member, and a threaded portion 23 is formed on its outer circumferential surface. The threaded portion 23 of the insertion portion 22 is configured to be able to threadably engage with the threaded portion 9 of the insert 7. In other words, the height-adjustable fitting 20 can be attached and detached to the precast deck 1 by screwing the threaded portion 23 of the insertion portion 22 into the threaded portion 9 of the insert 7 provided on the side surface 1 a of the precast deck 1.

[0025] The height adjustment bolt 10 is a metal bolt. The height adjustment bolt 10 has a threaded portion 11 and a head portion 12 provided at one end of the threaded portion 11. The tip 11a of the threaded portion 11 is flat. The threaded portion 11 of the height adjustment bolt 10 is configured so that it can be threaded into a threaded portion 25 formed in a through hole 24 of the height adjustment fitting 20. By screwing the height adjustment bolt 10 into the height adjustment fitting 20 and adjusting the length L1 (see Figure 2) of the height adjustment bolt 10 protruding from the underside of the main body 21 of the height adjustment fitting 20, the length L2 between the underside 1b of the precast deck 1 and the upper surface 5a of the steel girder 5 can be adjusted.

[0026] When adjusting the height of the precast deck 1, it is possible to install the precast deck 1 at a predetermined height and inclination angle by finely adjusting each of the multiple height adjustment bolts 10 connected to the precast deck 1. The height adjustment bolts 10 and height adjustment fittings 20 constitute a height adjustment jig 50.

[0027] 1 and 6, a hanging bracket 30 can be attached to the height adjustment bolt 10. The hanging bracket 30 has a connecting portion 31 that is connected to the height adjustment bolt 10, and a hanging portion 32 that is attached to the connecting portion 31.

[0028] The connecting part 31 is a rectangular parallelepiped metal member. A through hole 33 is formed in the connecting part 31, penetrating in the vertical direction. A threaded part 34 is formed on the inner surface of the through hole 33. The threaded part 34 of the connecting part 31 is configured to be able to threadably engage with the threaded part 11 of the height adjustment bolt 10.

[0029] The suspending portion 32 is connected to the opposing side surface of the connecting portion 31. The suspending portion 32 is a metal member formed in a substantially U-shape when viewed from the front. The suspending portion 32 is connected to the connecting portion 31 so as to be able to rotate freely. The suspending portion 32 is formed in a size that allows a crane jig or the like to be connected to it.

[0030] The process of adjusting the height of the precast deck 1 will now be described in detail. First, the height adjustment fittings 20 are attached to the inserts 7 of the precast deck 1. The height adjustment fittings 20 can be attached by screwing them into the inserts 7. Once the height adjustment fittings 20 have been attached to all of the inserts 7, the height adjustment bolts 10 are then attached. Note that a height adjustment jig 50 in which the height adjustment bolts 10 and height adjustment fittings 20 are connected may also be attached to the precast deck 1.

[0031] The height adjustment bolt 10 can be attached by screwing the threaded portion 11 into the threaded portion 25 of the height adjustment fitting 20. When attaching the height adjustment bolt 10 to the height adjustment fitting 20, a hanging fitting 30 is attached to the height adjustment bolt 10 that is attached to the corner of the precast deck 1 in plan view.

[0032] The hanging fitting 30 can be attached to the height adjustment bolt 10 by screwing the threaded portion 34 of the through hole 33 into the threaded portion 11 of the height adjustment bolt 10. The hanging fitting 30 is adjusted so that it is positioned immediately adjacent to the head 12 of the height adjustment bolt 10. As shown in Figure 1, the hanging fittings 30 are attached to the height adjustment bolts 10 at the four corners of the precast deck 1.

[0033] Once all of the height adjustment bolts 10 have been attached to the precast deck 1, the precast deck 1 is transported to a predetermined location using a crane or the like. At that time, a lifting jig or the like is connected to the lifting fittings 30, and the precast deck 1 is transported.

[0034] Once the precast slab 1 has been transported to a predetermined position in plan view, the height of the precast slab 1 is adjusted using the height adjustment bolts 10. The height of the precast slab 1 is adjusted by adjusting the amount that the height adjustment bolts 10 are screwed in, thereby adjusting the length L1. The height and inclination of the precast slab 1 are adjusted by adjusting the length L1 of all the height adjustment bolts 10. Once adjustments to the height and other aspects of the precast slab 1 have been completed, reinforcement work is performed between adjacent precast slabs 1, and epoxy is filled between the precast slab 1 and the steel girder 5. Next, the height adjustment bolts 10 are removed from the height adjustment fittings 20. After the height adjustment bolts 10 have been removed, the height adjustment fittings 20 are removed from the precast slab 1. Once all the height adjustment fittings 20 have been removed, concrete is poured between adjacent precast slabs 1.

[0035] By repeating the above-described steps, it is possible to install the precast slabs 1 and pour concrete between the precast slabs 1. According to this embodiment, when removing the height adjustment bolts 10 and height adjustment fittings 20 from the precast slab 1, it is only necessary to pull out the threaded portions, so the removal work can be easily performed without interfering with the reinforcing bars 3 protruding from the side surface 1a of the precast slab 1.

[0036] The precast deck height adjustment mechanism of this embodiment comprises an insert 7 provided on the side 1a of the precast deck 1, a height adjustment fitting 20 that is detachably attached to the insert 7, and a height adjustment bolt 10 that adjusts the height of the precast deck 1 relative to the upper surface 5a of the steel girder 5, and is configured so that the height of the precast deck 1 relative to the upper surface 5a of the steel girder 5 can be adjusted by adjusting the insertion length L1 of the height adjustment bolt 10 into the height adjustment fitting 20.

[0037] With this configuration, the height of the precast slab 1 can be adjusted using height adjustment fittings 20 that can be attached to and detached from inserts 7 provided on the side surfaces 1a of the precast slab 1, and height adjustment bolts 10, eliminating the need for fittings for height adjustment on the top surface of the precast slab 1. Furthermore, because filler concrete is poured onto the side surfaces 1a of the precast slabs 1 to connect adjacent precast slabs 1, it is possible to eliminate the need to fill in recesses or openings provided in the precast slab 1 later for height adjustment. In other words, the efficiency of manufacturing and construction of the precast slab 1 is improved, and the durability of the precast slab 1 itself can be improved.

[0038] In addition, the height adjustment fitting 20 has a main body 21 through which the height adjustment bolt 10 is inserted, and an insertion portion 22 that is connected to the main body 21 and can be inserted into the insert 7.Since only the insert 7 is embedded in the precast deck 1, after the height adjustment work for the precast deck 1 is completed, the height adjustment fitting 20 and the height adjustment bolt 10 can be easily removed from the insert 7 embedded in the precast deck 1, and the filler concrete can be poured without any problems.

[0039] Furthermore, because the hanging fittings 30 are configured to be detachable from the height adjustment bolts 10, the precast deck 1 can be easily transported by attaching the hanging fittings 30 to the height adjustment bolts 10. Since there is no need to provide a separate jig or the like on the precast deck 1 for attaching the hanging fittings 30, the work efficiency of manufacturing and constructing the precast deck 1 can be improved.

[0040] The above describes embodiments of the precast deck height adjustment mechanism and precast deck height adjustment jig of the present invention, but the present invention is not limited to the above embodiments and can be modified as appropriate within the scope of its gist.

[0041] For example, in this embodiment, the height-adjustable metal fitting 20 has the shape shown in Fig. 4, but is not limited to this. For example, a height-adjustable metal fitting 40 shown in Fig. 5 may also be used.

[0042] Although the shape of the main body 41 of the height-adjustable fitting 40 is different from that shown in FIG. 4, the configurations of the insertion portion 42, the threaded portion 43 formed in the insertion portion 42, and the through-hole 44 and the threaded portion 45 formed in the through-hole 44 are the same as those shown in FIG. 4. As shown in FIG. 5(c), the main body 41 is formed in a circular shape in side view. In other words, the main body 41 is formed in a substantially cylindrical shape. The main body 41 can be easily screwed into and removed from the insert 7. Note that the insertion portion 42 may be simply rod-shaped without the threaded portion 43. In this case, the height-adjustable fitting 20 can be attached to the precast deck 1 simply by inserting the insertion portion 42 into the insert 7.

[0043] Furthermore, in this embodiment, the hanging hardware 30 is configured to be detachable from the height adjustment bolt 10, but the configuration of the hanging hardware 30 is not limited to this.

[0044] The Sustainable Development Goals (SDGs) are 17 international goals adopted at the United Nations Summit in September 2015. The precast deck height adjustment mechanism of this embodiment can contribute to achieving one of the 17 SDGs, for example, goal 9, "Build resilient infrastructure, promote inclusive and sustainable industrialization, and foster innovation." [Explanation of symbols]

[0045] 1...Precast deck 1a...side 5a...Top surface of steel girder (reference surface) 7...Insert 10...Height adjustment bolt 20...Height adjustment bracket 21...Main body 22...insertion section 30...Hanging hardware 50...Height adjustment jig (precast floor slab height adjustment jig) L1...Length (insertion length)

Claims

1. an insert provided on the side of the precast deck; a height adjustment fitting detachably provided on the insert; and a height adjustment bolt for adjusting the height of the precast deck relative to a reference plane. A precast deck height adjustment mechanism that can adjust the height of the precast deck relative to the reference plane by adjusting the insertion length of the height adjustment bolt into the height adjustment fitting.

2. The height adjustment fitting is a main body portion through which the height adjustment bolt is inserted; an insertion portion connected to the main body portion and insertable into the insert; The precast deck height adjustment mechanism according to claim 1, wherein only the insert is embedded in the precast deck.

3. 2. A precast deck height adjustment mechanism as described in claim 1, wherein a hanging fitting is configured to be detachably attached to the height adjustment bolt.

4. A precast deck height adjustment jig comprising a height adjustment fitting and a height adjustment bolt used in the precast deck height adjustment mechanism described in any one of claims 1 to 3.

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