JP4395393B2 - Reinforced concrete protective fence post - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a reinforced concrete protective fence post formed by integrally molding a ground portion and a ground portion using high durability concrete, and a method for installing the same.

  Most of the conventional protective fences are made of steel pipes for both the support and the ground. For this reason, the service life is relatively short, usually around 15 years, due to the influence of salt damage and vehicle exhaust gas. In Patent 2958254, Patent 2974949, Patent Publication 2002-322622, etc., the ground part is made of reinforced concrete columns with high durability and the underground part is made of steel pipes, which are combined near the ground surface to ensure the durability of exposed parts. It was. However, this structure requires a large area for supporting the struts in the ground, so that the effective width of the traffic zone of vehicles and the like is narrowed, and the durability of the underground steel pipe and the ground reinforced concrete is imbalanced. Therefore, there is a disadvantage in that maintenance is difficult.

  In addition, examples of related technologies related to durability include Japanese Patent Publication No. 2001-220722 (protective fence) and Japanese Patent Publication No. 2001-336123 (concrete support). These use fiber reinforced concrete reinforced with metal fiber or polyethylene fiber, carbon fiber, aramid fiber, polypropylene fiber, vinylon fiber, etc. as a reinforcing material. However, there are many problems such as high manufacturing costs, poor workability of concrete and unstable quality, and difficulty in systematically placing it at the required location. There are many problems in terms of production cost and performance securing, such as troublesome production technology management for securing power, and practical application has been difficult.

On the other hand, a reinforced concrete protective fence post formed by integrally molding the underground part and the above-ground part has been desired conventionally, but there is a big problem in strength. In other words, collision-resistant guard fences have the condition that they do not collapse when impact energy of 60 kJ is applied. It was almost impossible to realize the pillars. Although the impact resistance is increased by increasing the size of the member, the shock absorbing function is decreased, and there is a possibility that an excessive acceleration of gravity is given to the collision vehicle.
Japanese Patent No. 2958254, page 1, Fig. 1 Japanese Patent No. 2958254, page 1, Fig. 1 Japanese Patent Publication No. 2002-322622, page 1, Fig. 1 Patent Publication 2001-220722, first page Patent Publication 2001-336123, page 1, Fig. 1

In view of the above prior art, the present invention integrally molds the ground part and the ground part using high-strength and highly durable concrete, and achieves a drastic improvement in the size and durability of the member, further improving the impact strength. The objective is to build a low-cost reinforced concrete protective fence post that can sufficiently improve the acceleration function of the collision vehicle .

  In the conventional strength test method for protective fence posts, the actual collision of the vehicle is assumed, and an impact of 60 kJ is applied, and it is specified only by energy that it does not bend more than a certain angle, that is, does not collapse. In order to comply with this rule, the member strength may be increased. However, this indicates that when energy above the specified value is applied, it may be completely collapsed, and the design has no margin. Therefore, in the present invention, an additional proposal is made for the strength test method in order to make full use of the characteristics of reinforced concrete. In other words, the collision actually occurs within a short time of 0.5 to 1 second, but in order to more completely prevent the collision vehicle from departing from the road, the toughness of the column in the behavior of the collision vehicle on the way In order to make it possible to accept with the stickiness caused by the above, it is conditioned that the horizontal load F is applied for a continuous time as a test condition. By making the horizontal load appropriate, the energy test can be omitted. That is, the horizontal load corresponding to the energy test of 60 kJ is set to 2 tons, and a larger value, for example, 3 tons is set as the horizontal load F. This horizontal load F is continuously applied, and it is tested that it does not deform more than a certain amount during this time. As a result of testing with the horizontal load F thus determined, it has been confirmed by 30 or more collision experiments that the energy test of 60 kJ can be cleared. Thus, in addition to the condition that the vehicle does not collapse simply, it can be ensured that deviation from the road can be prevented even with a larger load. The causal relationship that the test method of a simple beam that applies a load in the vertical direction can be substituted for a collision test is a matter found by the present inventors. Thereby, it can be set as a tenacious pillar which can endure a collision of 60 kJ. As for the horizontal load in the actual test, a load f from the vertical direction may be applied to the intermediate position in a state where pillows are put on both ends and the support is turned over. It is only necessary to simulate a state in which a horizontal load from the inside of the road is applied to the cushioning material mounting position in a state where the column is erected. In this case, the load f is appropriately determined so as to satisfy the same condition as the horizontal load F in consideration of how to set the pillow. The direction of load application must be appropriate so that it can be applied from the inside of the road. As a result, it is possible not only to withstand an impact of 60 kJ, but also to be a sticky column.

  Naturally, the sticky portion also exhibits an impact mitigating action, so that the acceleration applied to the collision vehicle can be reduced significantly.

The reinforced concrete protective fence post of the present invention is a reinforced concrete protective fence post of a protective fence in which shock absorbers for shock mitigation are arranged in a plurality of stages inside a post erected along the road surface,
The strut is formed of an underground portion embedded in the ground and a ground portion having a mounting portion for mounting the cushioning material, and is made into an integrally molded product using high-strength durable concrete together with the mounting portion, When a horizontal load for testing, which becomes a collision load, is applied to the ground portion of the support column, a plurality of components arranged vertically in the support column so that the amount of deformation due to the horizontal load is within a certain range of tolerance. Vertical reinforcing bars and a plurality of reinforcing reinforcing bars arranged at a predetermined pitch over the entire region from the top to the bottom so as to surround the vertical reinforcing bars, and among the vertical reinforcing bars, the reinforcing bars on the road side Is thicker than the reinforcing bars on the outside of the road, and the reinforcing reinforcing bars are densely arranged in the vicinity of the road surface .

  In the reinforced concrete protective fence column of the present invention, a column composed of an underground part and an above-ground part is erected, a horizontal load F (for example, 3 tons) corresponding to a collision load is given to a specified height, and near the road surface of the column. The allowable deformation amount α at a specified height (for example, 650 mm) is within a certain value (for example, 300 to 400 mm). The magnitude of this horizontal load is determined experimentally as a force that is equivalent to an energy of 60 kJ. As a result, when the specified impact (60 kJ) is applied to the support column of the present invention, it may bend within the allowable range α, but it will not collapse, and it will have a tenacious structure that is flexible and has low impact protection. It can be a fence. The allowable value α can be substituted by the angle θ. It can be a reinforced concrete column with a diameter of 12-15cm, which is as thin as possible.

To a tenacious struts not only used compression strength 70N / mm ² or more high-strength concrete, shall be the proper reinforcement rebar. Use at least four reinforcing bars that run along the columns and that are thick and strong on the inner side of the road. Also, it is achieved the pitch of reinforcing iron muscle near the road surface or the like to close.

According to reinforced concrete fences strut of the present invention, since the inside has a structure that allows the bending caused by the collision load by thicker than the outer reinforcing bars, eliminates excessive strength design, Tsu coupled with a high-strength high durability Conch cleat It is possible to mold a reinforced concrete strut that is as thin as possible with a diameter of about 12 to 15 cm and yet has sufficient strength . High strength durable concrete can be considerably longer and 4 times or more than the durability to conventional products. The maintenance, the entire primary posts is damaged for manufactured concrete it is possible to reduce the maintenance costs of the corresponding can Rutotomoni fences only cushioning member does not occur only periodically updated.

  Further, according to the present invention, since the diameter is small and it can be molded with high design properties, the occupation width of the column in the vicinity of the road surface can be reduced by about 12 cm, which can be reduced by about 26% compared to the conventional product, and there is also room for the vehicle passage section. Can bring.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a reinforced concrete protective fence post according to an embodiment of the present invention, wherein (a) is a rear view, (b) is a side view, and (c) is a front view.

  As shown in FIG. 1, a reinforced concrete protective fence column (hereinafter also referred to simply as a column) 1 of the present invention is planned to stand on a road surface 2, and an underground portion 3 and a road surface located below the road surface 2. 2 and a ground portion 4 located above 2, and these are integrally molded using high-strength and highly durable concrete.

  The diameter of the underground part 3 is as thin as possible, about 12 to 15 cm. The ground part 4 has an extension part having the same diameter as the underground part 3, and a covering part 5 for design and strength compensation and a mounting part 7 for the buffer material 6 are formed around the extension part. Although the buffer material 6 is shown as an example of a pair of upper and lower two logs, it is not limited to this.

The mounting portion 7 receives the two cushioning materials in a state where each cushioning material 6 is abutted at the center position from the left and right in the figure (a), and firmly connects the cushioning materials 6 to each other. And a through hole 8 for inserting a fastening bolt is provided through the support column in the lateral direction. In the through hole 8, one side of each of L-shaped bolts (not shown) with screws at both ends is inserted through one nut member, and a U-shape is formed by mutual screwing to the nut. The bottom of the U-shaped bolt is inserted, both ends of the U-shaped bolt protrude forward (to the right in the (b) figure), the hole provided in the log end is inserted into the protruding screw part, both logs Is fixed in contact with the receiving surface 7a. Accordingly, the log cushioning material is firmly joined by the U-shaped bolt on the receiving surface 7a. In order to increase the buffering effect, protrusions, rubber materials, and the like may be interposed on the receiving surface 7a. In order to increase the buffer function, the distance (block out) between the receiving surface 7a and the surface of the support column 1 is 90 mm or more.

As the high strength and high durability concrete, high strength concrete having a compressive strength of about 70 N / mm ² can be used. In terms of strength, 70 N / mm ² or more is sufficient, but fluidity is good and high durability is an essential requirement.

The high strength and high durability concrete, and more cement 330Kg per concrete 1 m ^3, the inert fine powder, coarse aggregate, fine aggregate, and mixed with water, to which an appropriate amount of water-reducing agents, admixtures, shrinkage reducing In particular, the bran value of the inert fine powder is set to 3000 cm ² / g or more, and the sum of the specific surface area of the cement composition and the specific surface area of the inert fine powder composition is 25000 m. low shrinkage ultrahigh strength concrete composition was ^{2 ~500000m 2} can be used. This composition is particularly suitable for molding complex shapes with high fluidity without cracking at low shrinkage. Dense concrete products can be finished with water cement ratio within 45%.

  Fig.2 (a) is a side view which shows the bar arrangement state of a reinforcing bar. As shown in the drawing, 16 mm is used as the rebar S1 on the road outer side, whereas 19 mm is used as the rebar S2 on the road inner side. In addition, the reinforcing bar S3 has a dense arrangement pitch near the road surface. Thus, since the reinforced concrete guard fence post 1 of the present invention has orientation, it must be installed and constructed in a regular arrangement.

  FIG. 2B is an explanatory side view showing an embodiment of a method for installing the column 1 shown in FIG. 1 on the road surface 2. In the present invention, an insertion hole 10 having a diameter D2 larger than the diameter D1 of the support column 1 is formed vertically in the underground 9 and the underground portion 3 of the support column 1 is inserted into the insertion hole 10 and then inserted into the underground portion 3 of the support column 1. A filler 11 such as sand or asphalt is filled between the inner wall surfaces of the holes 10.

  The strut 1 of the present invention has a ground height H1 = 650 mm and a horizontal load F of 3 tons, the strut 1 does not collapse or the deformation α is within 300 to 400 mm, preferably within 300 mm. Design to fit. That is, the shape, dimensions, and content of reinforced concrete are determined so that this condition can be satisfied. In particular, as shown in FIG. 2 (a), the reinforcing bar FFs (S1, S2, S3) are important to be arranged from the ground part 3 to the ground part 4 so as to resist the horizontal load F. The arrangement of multiple cylindrical surfaces is used for precise bar arrangement. The bending of the support column 1 occurs in the underground 9 at a position 1/2 of the total length L.

  Conventionally, in addition to the standard that was not to be collapsed when an impact level of 60 kJ was applied, a test with a horizontal load F equal to or greater than this was performed. The standard can be cleared, and in addition, a sticky and stable design can be obtained. As a result, in the present invention, a high-quality reinforced concrete protective fence post could be constructed without using special techniques such as fiber reinforced concrete.

  In addition, as shown in FIG. 2, in the present invention, since the filler 11 such as sand is put into the gap between the underground portion 3 of the support column 1 and the insertion hole 10, the dynamic impact property is further improved.

FIG. 3 shows an embodiment in which the acceleration received by the vehicle when the actual vehicle collides with the support 1 shown in FIG. 2 is measured. Table 1 shows measured values of vehicle behavior and impact. The vehicle speed was 34.8 km / h and the collision angle was 16 °. Since the total weight of the vehicle is 20.15 tons, the impact is 71.2 kJ against the standard value of 60 kJ. The horizontal axis is the time (ms), the ordinate indicates the acceleration ^{(m / s 2 / 10ms)} . A solid line indicates a vehicle traveling direction (X direction), and a broken line indicates a component value in a direction (Y direction) orthogonal thereto.

When the vehicle comes into contact with the surface of the cushioning material 6 at time t1, the accelerometer is activated, and a sudden rise is started at time t2. Up to now, the initial buffer action by the buffer material 6 and the block-out BK has been acting strongly. At this time, a vehicle with a speed of 34.8 km / h travels 9.7 cm per 0.01 second (10 ms) because it is 9.7 m per second. Since the collision angle is 16 °, it is 2.5 cm in the direction orthogonal to the column 1. At the head position at this moment, the acceleration changes according to the magnitude of the buffering action in the block out BK. In the present example, it is suppressed to 50m / s ² / 10ms. In general, depending on the cushioning effect of the time, there is a possibility that the acceleration exceeds the (S) and standard value Road Association stipulated 90m / s ² / 10ms.

In the column 1 of the present invention, first, the back surface of the column 1 in contact with the road surface exhibits a buffering action in a short time of several ms through the filler 11, and is bent due to partial destruction at time t3. At this time, buffering support is performed between time t2 and time t3, the destruction time of the support column 1 is delayed, and the acceleration value is prevented from becoming large. At time t3 to t4, an acceleration value 40~50m / s ² / 10ms, absorbs most of the energy of 71.2KJ. Thus, the energy of the vehicle is absorbed, and thereafter, the vehicle is stopped at time t6 while applying a reaction force to the vehicle until time t5. The approach stroke was 14cm. Thus, in the reinforced concrete protective fence post 1 of the present invention, the sticking is strong, it is bent but not greatly bent, and the vehicle can be received flexibly and without departing from the road.

As described above, in this embodiment, by interposition of the filling material 11, the acceleration at time t3 is suppressed to rise to 90m / s ² / 10ms nearby. Further, by allowing bending by partial destruction post 1, as a smooth acceleration of the time t3 to t4, thereby suppressing the maximum acceleration of about 50m / s ² / 10ms. This value is 25 to 30% less relaxed than conventional products in which the ground part is made of concrete, for example, a wooden guard fence disclosed in Japanese Patent Application Laid-Open No. 2002-322622. This is due to a special effect of the sticky reinforced concrete support 1. Compared to the standard, it is relaxed by 40% or more. Indeed, we were able to obtain optimal characteristics as a protective fence post.

  Further, according to the support column 1 of the present invention, as shown in FIG. 1 or 2, the occupation width of the support column 1 in the vicinity of the road surface 2 can be set to about 12 cm, which can be reduced by about 26% compared to the conventional product. It was also possible to afford a vehicle traffic zone.

  Furthermore, since the support of the present invention has a durability that is more than 4 times longer than that of a steel support, it can be handled only by changing the cushioning material at the time of renewal. The maintenance cost of the fence can be reduced.

  In FIG. 2, the mounting height of the lowermost cushioning material 6 is set to H2, the space generated exceeding 300 mm from the road surface 2 is excluded, and a blockout BK of 90 mm or more is maintained. Therefore, the tires or wheels of the vehicle, particularly a passenger car, do not fit or mesh with the cushioning material, and the sliding operation in a minute time is promoted between the times t2 to t4 shown in FIG. Has eased. In the present invention, due to these synergistic effects, the acceleration can be considerably reduced as compared with the conventional product.

 FIG. 4 is a rear perspective view showing another embodiment of the reinforced concrete protective fence post of the present invention. Members having the same functions as those in FIGS. 1 and 2 are denoted by the same reference numerals.

  The support 1a shown in FIG. 4A differs from the support 1 shown in FIGS. 1 and 2 in that the shape of the covering portion 5a is different from that of the support 1 shown in FIG. The difference is that a mark 12 is provided. The figure clearly shows the level difference between the underground portion 3 and the covering portion 5a, but in reality, this boundary is manufactured to such an extent that it is difficult to distinguish visually. Therefore, the embedment position can be accurately determined with reference to the mark 12. (B) In the column 1b shown in the figure, the mark 12 is omitted. As described above, in the support column 1a of the present invention, the covering portion 5a and the portion associated therewith can be freely set in shape, and the design and the associated function can be enhanced.

  A preferred test method is shown in FIG. As shown in the figure, the pillows 13 and 14 are placed at a specified interval of 1900 mm, and a vertical load of 4 tons corresponding to the horizontal load of 3 tons is applied to the center. The bending moment of a cantilever beam when a 4-ton load is applied is acceptable if the 19KN · m deformation α is 300 to 400 mm. As already shown, since the column 1 has directionality, it must be properly arranged so that the side on which the cushioning material is attached is the lower surface.

  According to this test method, since the vertical load f can be substituted in the test method for applying the horizontal load F, it is possible to easily perform a test with ease and reproducibility. In addition, since the load can be increased to 4 to 5 tons with respect to a prescribed vertical load f, for example, 4 tons, and the creep amount can be traced and the creep test can be performed, the degree of stickiness can be shown in a graph.

  The present invention is not limited to the above embodiment, and can be appropriately modified in design without departing from the gist of the present invention, and can be implemented in various aspects.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a reinforced concrete protective fence post according to an embodiment of the present invention, (a) a rear view, (b) a side view, and (c) a front view. Shown with the underground part buried and standing on the road surface. (A) The figure shows a bar arrangement, and (b) is a side explanatory view showing the state where the ground part is refracted in the road shoulder direction. It is explanatory drawing which shows the Example of the time at the time of the collision shown in FIG. 2, and an acceleration. It is a back perspective view showing other embodiments of a reinforced concrete protection fence post of the present invention. It is explanatory drawing which shows the test method applied to the reinforced concrete protective fence support | pillar of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a, 1b Reinforced concrete protective fence post 2 Road surface 3 Underground part 4 Ground part 5 Cover part 6 Buffering material 7 Mounting part 7a Receiving surface 8 Through hole 9 Underground 10 Insertion hole 11 Filler 12 Marking 13, 14 Pillow F Horizontal Load f Vertical load
BK Block out H1, H2 Height FF (S1, S2, S3) Reinforcing bar α Deformation amount

Claims (1)

It is a protective fence post made of reinforced concrete of a protective fence in which shock absorbers for cushioning impact mitigation are arranged in multiple stages inside the post that is erected along the road surface,
The strut is formed of an underground portion embedded in the ground and a ground portion having a mounting portion for mounting the cushioning material, and is made into an integrally molded product using high-strength durable concrete together with the mounting portion, When a horizontal load for testing, which becomes a collision load, is applied to the ground portion of the support column, a plurality of components arranged vertically in the support column so that the amount of deformation due to the horizontal load is within a certain range of tolerance. Vertical reinforcing bars and a plurality of reinforcing reinforcing bars arranged at a predetermined pitch over the entire region from the top to the bottom so as to surround the vertical reinforcing bars, and among the vertical reinforcing bars, the reinforcing bars on the road side Is formed thicker than the reinforcing bars on the outside of the road, and the reinforcing reinforcing bars have a dense arrangement pitch in the vicinity of the road surface .

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