JPH0237442B2 - DOROKAKUFUKUKOHO - Google Patents

Description

[Detailed description of the invention] Industrial applications This invention relates to a road widening method.

Prior Art The present applicant has disclosed an invention described in Japanese Patent Application Laid-Open No. 71904/1983 as a road widening road using a projecting method. In this invention, an overhanging girder is supported on support piles driven into the valley side end of an existing road and partially overhangs from the widening side end of the existing road, and the mountain side end of the overhanging girder The floor slab is fixed by an anchor, and the floor slab is placed on the overhanging girder via a longitudinal girder in the direction of road travel.

The projecting widening road has the advantage that it does not require the labor of cutting and filling soil during construction, and has the extremely large effect that it has a stable structure due to the support piles and anchors.

Problems to be Solved by this Invention The problem with the above invention is that if the road conditions are inadequate for transporting materials, it is extremely difficult to transport huge objects such as floor slabs to the site. It was difficult.

In order to solve these problems, it is possible to construct formwork on site and widen the road.
In order to assemble the formwork by extending it out from the existing road into the valley, it is an extremely difficult task to erect shoring into the ground on the deep valley side.

Means for Solving the Problems The road widening method according to the present invention is a road widening method in which a prestressed road is placed in a direction perpendicular to the traveling direction of the road, fixed to the edge of the mountain using a reaction anchor, and The above-mentioned problems are solved by suspending the formwork from partially overhanging construction support beams and pouring concrete.

Embodiment The present invention will be described in detail below based on an embodiment shown in the drawings.

(1) Support pile driving Support piles 1 will be driven at specified intervals along the valley side edge of the existing road. As the support pile 1, a PC pile or the like can be used, and a known driving method can be used by using an earth auger or the like.

A block 2 is placed on the support pile 1. A reinforcing bar 3 is made to protrude from the side of the block 2.

(2) Leveling of the existing road Leveling mortar, leveling concrete, etc.18 have been placed on the surface of the existing road. It is also possible to level the surface using dry mortar.

(3) Installation of reaction anchors Reaction anchors 4 will be installed at predetermined intervals along the mountain side edge of the existing road in correspondence with the support piles 1.

First, a hole 5 is formed in the ground, and a prestressed steel material 6 is inserted. The lower half of the PC steel material 6 is fixed in the drilled hole 5 by injecting grout material 7, and the upper end is made to protrude above the ground surface. Blocks 8 and 9 having reinforcing bars protruding laterally are placed on the ground surface on the left and right sides of the drilled hole 5 in a direction perpendicular to the road traveling direction.

Further, instead of the blocks 2, 8, and 9, steel members such as H steel may be used.

(4) Installation of the erection support beam Place the erection support beam 1 on blocks 2, 8, and 9.
0 is installed in a direction perpendicular to the direction of road travel.

As the construction support beam 10, H-type steel, I-type steel, etc. can be used, and in the embodiment, two I-type steels are used side by side.

The mountain side end of the erection support beam 10 applies a prestress force downward by the reaction force anchor 4, and a part of the valley side overhangs from the end of the existing road. That is, the end portion of the PC steel material 6 is made to protrude upward through the space between the two I-beams, penetrated through the bearing plate 11, and fixed with an erection nut or wedge 12. The prestressing force is applied to the erection support beam 10 by tensioning the PC steel material 6.
The tension load is carried by blocks 8 and 9.

The length of the part of the construction support beam 10 extending toward the valley side is about half the length of the support beam 10, and is made sufficiently longer than the width of the road to be widened.

(5) Installation of formwork The formwork 13 is suspended from the erection support beam 10. The formwork 13 has a box shape and is suspended from a hanging tool 14 hooked to the construction support beam 10.

Reinforcing bars are arranged from the existing road to the formwork 13, and reinforcing materials such as H steel are arranged in a direction perpendicular to the road traveling direction. Alternatively, an unbonded prestressed steel material containing prestressed steel material within a sheath may be provided at an appropriate distance in the direction of road travel. Unbonded PC steel materials will be installed in a direction perpendicular to the direction of road travel.

(6) Concrete pouring From the existing road to formwork 13, block 2,
Concrete 15 is poured so that 8 and 9 are integrated. The mountain side of the erection support beam 10 tends to rise due to the weight of the concrete 15, but since a prestress force is applied to the reaction anchor 4,
The prestress force prevents lifting.

Although compressive force acts on the block 2, the block 2 is supported by the support pile 1 and is prevented from sinking.

(7) Prestress introduction If prestressing is placed from the existing road to the formwork 13, the concrete 15 will be unbonded after hardening.
Tensions the PC steel material to apply prestress force.

In addition, a jack is placed on the construction support beam 10,
Re-tension the PC steel material 6 of the reaction anchor 4. After that, using the notch 10a formed on the mountain side of the erection support beam 10, attach a permanent nut or wedge 1.
6 fixes the PC steel material 6 to the concrete 15 and applies prestress force to the concrete 15. 17 is a bearing plate.

After fixing the PC steel material 6, grout material 7 is injected into the upper part of the drilled hole 5.

The erection nut 12 and bearing plate 11 are removed, and the PC steel material 6 is cut at the upper part of the permanent nut 16.
The permanent nut 16 is buried in mortar or concrete.

The formwork 13 and the erection support beams 10 are removed.

As mentioned above, the widening road formed with concrete 15 is supported by the support piles 1, and the mountain side end is given a prestress force by the reaction anchor 2, so that it acts on the overhanging part. It is possible to withstand the loads that occur.

(8) Other configurations In addition to the configurations described above, it is also possible to use unbonded PC steel material as the reaction anchor 4.

In addition, concrete 15 contains not only the direction perpendicular to the direction of road travel, but also the direction parallel to the direction of road travel.
Prestressing force may also be applied by arranging prestressing steel.

Effects of the Invention Since the present invention has the configuration as described above, it is possible to obtain the following effects.

The overhang method eliminates the need for cutting or filling, greatly reducing the amount of earthwork and shortening the construction period.

There is no need to cut the mountain side, so there is no damage to the existing slope. Therefore, there is no need to carry out new slope protection work.

Since supporting piles are installed at the end of the existing road, a more stable structure can be obtained than one created by filling in the valley side. There is also no need to worry about contaminating rivers, etc.

When a live load acts only on the overhanging portion, the reaction force can be taken by the anchor provided at the mountain end, resulting in a stable structure.

Since the formwork is suspended from the construction support beams extending from the edge of the existing road, there is no need to assemble support on the valley side ground, making construction extremely easy.

There is no need to transport huge materials such as floor slabs, and it is easy to transport even to sites with poor road conditions.

The reaction anchor is capable of applying a prestressing force to both the erection support beam and the overhanging concrete portion of the widening road, and can speed up construction.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of the road widening method according to the present invention, FIG. 2 is a vertical cross-sectional view in a direction perpendicular to the road traveling direction, and FIG. 3 is a vertical cross-sectional view of a reaction force anchor in the road traveling direction. , FIG. 4 is a longitudinal sectional view of the upper part of the support pile in the direction of road travel. 1... Support pile, 2... Block, 3... Rebar, 4... Reaction anchor, 5... Hole drilling, 6... PC steel material, 7... Grout material, 8, 9... Block, 10... Support beam, 11
...Bearing plate, 12...Temporary nut, 13...Formwork, 1
4... Hanging equipment, 15... Concrete.

Claims (1)

[Scope of Claims] 1. Support piles are driven at predetermined intervals along the valley edge of the existing road, reaction anchors are installed corresponding to the support piles along the mountain edge of the existing road, and erection is carried out. One end of the support beam is supported on a reaction anchor, the other end is extended from the existing road, the middle is supported on a support pile, and the reaction anchor applies downward prestress to one end of the mountain side of the erection support beam to support the erection. A formwork is suspended from the part of the beam that overhangs the existing road, reinforcing bars are arranged from the existing road to the formwork, and reinforcing materials are placed at appropriate intervals in a direction perpendicular to the direction of road travel. Concrete is cast from the road to the formwork in one piece, and after the concrete hardens, the PC steel of the reaction anchor is re-tensioned and fixed to the concrete, and then the formwork and erection support frame are removed. Characteristic road widening method. 2 In the above construction method, blocks are placed on the support piles to support the erection support beams, and after concrete is poured,
A road widening method according to claim 1, characterized in that the road widening method is integrated with concrete. 3. Drive support piles at predetermined intervals along the valley edge of the existing road, install reaction anchors corresponding to the support piles along the mountain edge of the existing road, and attach the erected support beam to one end of the support pile. It is supported on a reaction anchor, the other end is extended from the existing road, the middle is supported on a support pile, and the reaction anchor applies downward prestress to one end of the mountain side of the erection support beam, causing the erection support beam to overhang from the existing road. The formwork is suspended from the existing road, and reinforcing bars are placed from the existing road to the formwork, and unbonded at appropriate intervals in the direction perpendicular to the direction of road travel.
After arranging the PC steel materials, pour concrete from the existing road to the formwork so that they are integrated, and after the concrete hardens, tension the unbonded PC steel materials,
A road widening method that is characterized by re-tensioning the prestressing steel of the reaction anchor and fixing it to concrete, and then removing the formwork and erection support frame. 4 In the above construction method, blocks are placed on the support piles to support the erection support beams, and after concrete is poured,
The road widening method according to claim 3, characterized in that the road widening method is integrated with concrete.