JPS6356365B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates primarily to guardrails used on roads, and more particularly to concrete guardrails that are easier to maintain than steel guardrails.

Guardrails generally installed on roads are
This is to prevent accidents in road traffic, but in snowy areas, only less than 20% of damage to metal guardrails and guard ropes is due to collisions with automobiles, and damage caused by direct pressure from snowfall, avalanches, etc. 80% of the damage is caused by lateral pressure from snowplows. Additionally, there are many disadvantages in terms of maintenance and management, such as breakage and rust of the rail joints for absorbing impact forces and the brackets that support the ropes.

A road protection wall made of a concrete plate with a wire mesh inside as a conventional concrete guardrail is disclosed in Japanese Utility Model Application Publication No. 51-130623, and a rail made of a thin metal plate coated with resin concrete is bolted to a metal support. Fixed guardrails have been proposed in Japanese Utility Model Publication No. 52-23143, but the former is heavy and difficult to repair, and is also unsightly, while the latter uses metal supports. Therefore, there is a problem of corrosion, and
It has the disadvantage of not being able to fully absorb the impact of a collision.

In view of the above-mentioned circumstances, the present invention is relatively lightweight, allows for easy construction and repair, can absorb impact in the event of a collision well, and has sufficient strength against direct pressure from snow accumulation and lateral pressure from snowplows. The purpose is to provide a guardrail as a concrete guardrail to eliminate the above-mentioned conventional drawbacks, and to achieve this purpose, the characteristic configuration is a concrete support and a concrete support that is fixed to the support. A plurality of prestressing steel materials are arranged in the longitudinal direction of each of the supports and rails, and the cross-sectional shape of the rail is a double-walled structure with a shock absorption space, and the double-walled By placing the above-mentioned PC steel materials on each side and introducing pre-stress into the above-mentioned rails and pillars, a guardrail that is relatively thin and lightweight and has sufficient strength is constructed, and a double-walled structure in which pre-stress is introduced. The impact absorption space enables effective absorption of impact.

Next, an embodiment based on the above characteristics will be described with reference to the accompanying drawings.

1 is a post made of prestressed concrete, and a plurality of PC steel wires 2 or PC
The steel rods are arranged using a pre-tension method or a post-tension method, for example, 150 mm x 200
It has a rectangular cross section of mm and has sufficient strength.

3 is a rail made of prestressed concrete, and a plurality of PC steel wires 4 or
PC steel bars are arranged by pre-tension method or post-tension method, e.g.
A small rail of 350 mm, width 250 mm, and length 4000 mm has sufficient strength, and the cross-sectional shape of the rail 3 is double-sided with a shock absorption space 5 in the center, such as an inverted U shape, an inverted U shape, or a L shape. It has a wall structure, and a PC steel wire 4 or a PC steel bar is disposed in each of the wall portions 6, 6a and a connecting portion 7 of the wall portions 6, 6a, and the wall portions 6, 6a each have, for example, It has sufficient strength with a wall thickness of 50 mm.

Note that reinforcing steel wires (not shown) are arranged in the length direction of each of the rail 3 and the support 1, and the rail 3 is provided with reinforcing steel wires 8 having the same cross-sectional shape.
are arranged at multiple intervals in a direction perpendicular to the length direction. Further, rectangular reinforcing steel wires 8 are arranged on the support column 1 at multiple intervals in a direction perpendicular to the length direction.

In addition, Fig. 1 shows the case where the support column 1 is buried in the soil, but if it is not buried in the soil but is erected on concrete and installed on the road surface of a bridge, bypass road, etc., the embedment length is The length is short. Therefore, the comparatively thin rail 3 and support column 1 constitute a concrete guardrail with sufficient rigidity, stiffness, and elasticity, so it is easy to construct and repair, has a good appearance, and is easy to use while driving. When a vehicle collides with the guardrail of the present invention, the impact force is first absorbed by one wall 6 of the double walls 6, 6a, and after the concrete of that wall 6 is damaged, it is absorbed by the impact absorption space 5, and then the impact force is absorbed by the impact absorption space 5. The impact force is absorbed and dispersed in stages by being absorbed by the other wall portion 6a. Moreover, PCs arranged in the length direction of rail 3
Impact force is absorbed more effectively by the sufficient bending rigidity of the steel wire 4 or the PC steel bar.
Even if the concrete of the double wall parts 6, 6a is damaged, the PC steel wire or PC steel rod can sufficiently absorb the impact of the car and prevent it from flying off the road.
Also, damage to the vehicle body can be minimized.

Further, the upper part of the pillar 1 is formed to gradually become thicker as it advances toward the upper end, and a protrusion 10 having a diameter smaller than that of the pillar 1 is formed at the upper end.
The PC steel wire 2 arranged in the length direction of the protrusion 1
It has reached the tip of 0.

Further, the rail 3 is formed with a hole or a recess 11 into which the projection 10 fits, and on both sides of the hole or recess 11 there are holes along the length of the rail 3.
A PC steel wire 4 or a PC steel bar is provided. A rail 3 is fitted from above the support 1.
Therefore, the rail 3 can be fitted onto the support column 1 with one touch, and construction and repair are easy. Furthermore, since the rail 3 is a thin and short block body, and 1 block A is assembled in a prefabricated manner, even if it is damaged in a collision, it can be repaired by simply replacing 1 block A with a new one as shown in Figure 1. Therefore, repair work can be easily carried out without causing deformation and damage to long sections in the road extension direction, unlike conventional ones. Moreover, the rail 3 and the support column 1 can exhibit sufficient strength against the vertical load due to snow accumulation and the horizontal load during snow removal.

As described above, the present invention includes a concrete support column,
A concrete rail is fixed to this support, and the length of each support and rail is
In addition to arranging a plurality of prestressing steel materials, the cross-sectional shape of the rail is made into a double-walled structure with a shock absorbing space, and the above-mentioned prestressing steel material is provided in each of the double structures. The concrete guardrail is relatively lightweight, easy to construct and repair, and has a good appearance. Moreover, since the concrete structure has made it possible to absorb and disperse the impact in stages to reliably prevent unexpected accidents involving automobiles, it has excellent effects as a concrete guardrail.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view showing the guardrail of the present invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig.
The figure is a cross-sectional view taken along the line B--B of the same as above, and FIG. 4 is an enlarged cross-sectional view taken along the line CC of the same. 1... Prop, 2... PC steel wire, 3... Rail,
4...PC steel wire, 5...Shock absorption space, 6, 6a
...Double wall section.

Claims (1)

[Claims] 1 Equipped with a concrete support and a concrete rail fixed to the support, a plurality of prestressing steel members are arranged in the length direction of each of the support and the rail, and the cross-sectional shape of the rail is designed to have a shock absorption space. 1. A guardrail having a double-walled structure, each of which has a prestressed steel material.