JP2005083068A - Cushioning material for civil engineering structure, rock fall preventive fence, and its construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cushioning material for civil engineering structure and a rock fall preventive fence, in which a wire basket having a preset capacity is constituted so that the cushioning performance is never dispersed even if thinnings differed in size are put therein, in order to ensure a desired void ratio when the thinnings are put therein. <P>SOLUTION: The edge parts of mesh bodies 10a, 10b, 10c, 10d and 10e for front surface, back surface, both lateral side surfaces and bottom surface are connected in each edge of a rectangular parallelepiped body through a coil-like connecting fitting 12 to constitute the rectangular parallelepiped wire basket 7 having a preset capacity and substantially the same height as the length of the thinnings 8 with an opened upper surface 13. A plurality of thinnings 8 is neatly arranged in the wire basket while keeping an optimum void ratio enabling the cushioning movement of the thinnings 8. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention is a civil engineering structure using a thinning material used to prevent the collapse of stones, rocks, surface soil, etc. that occur on steep slopes on mountainsides, road construction, steep slopes created by land preparation, etc. The shock-absorbing material, and the protection fence and falling rock prevention fence constructed by this.

As this type of prior art, as a cushioning material for preventing the breakage of the protective fence body, a fallen object prevention material (JP-A 2001-164521) using waste tires, or a fall prevention fence (actual No. 6-26566), and there is a disclosure technique such as a mounting bracket (Japanese Patent Laid-Open No. 9-242025) in a rock fall prevention fence made of a cushioning material such as a foaming resin, but the thinning material is not used in each of the above conventional examples .

  On the other hand, there are also examples of fall protection fences such as falling rocks that use thinned wood as cushioning material. However, in this case, there are several ways to use thinned wood. Generally, there are a method of fixing with a nail and (2) a method of installing a thinned timber bundled with iron wires by attaching it to a prevention wall.

  When the protective fence is constructed using the thinned wood by the method (1), the construction work on site is very large and the workability is poor. Further, in the method (2), the thinning material exerts a buffering function because the thinning material moves and absorbs the impact when the fallen rock hits the thinning material. In this case, in order to ensure the optimum buffer movement of the thinned wood, it is necessary to secure a ratio between a ratio of a large number of thinned wood in a certain volume and a space generated therebetween, that is, a certain gap. . The void is generally expressed by a void ratio (for example, a void ratio of 50% to 55%).

  The porosity is a ratio between the cross-sectional area occupied by each thinned material and the size of the space formed between each thinned material when a large number of thinned materials are accommodated in a certain volume. Therefore, by calculating the size of the container that holds the thinned wood, the overall cross-sectional area of the thinned wood, and the size of the space at that time, the number of thinned wood necessary to form the desired porosity is calculated. Is possible. If the size of the container is determined, it is easier to calculate the number of thinned materials necessary for the desired porosity when the thickness of each thinned material is substantially uniform.

  In reality, however, the size (thickness) of thinned wood varies widely, and in the installation at the site, the necessary number of thinned wood piled up at the site accumulation site is appropriately selected and the required number is tied with iron wire. Since it is not uniform and it is unclear how much porosity has been created in the thinned wood, the buffer performance varies when installed as a protective fence. Even if thinned wood of various thicknesses is covered with a net, the desired porosity cannot be ensured by itself, and the buffer performance will still vary. Furthermore, when thinned wood is bound with iron wire, falling rocks may collide with the iron wire, the iron wire may break and the thinned wood may be scattered. In addition, the actual situation is that little attention has been paid to the porosity itself that maximizes the buffer performance of thinned wood.

   As other conventional techniques, there is a slope protection method (JP 2001-172777) used as a civil engineering member by putting thinned wood in a net, and a gabion structure (JP 2001-234519) used as a buffer material, Any of the above-mentioned net fences are horizontally placed for aligning and fixing the thinned wood. Moreover, the net fence is not configured as a container of a predetermined size set in advance for securing a predetermined porosity when the thinned material is accommodated. Therefore, in the prior art, it is unclear how much porosity has been achieved when thinned wood of different sizes are accommodated in the net fence, and the buffer performance varies.

JP 2001-164521 A Japanese Utility Model Publication No. 6-26566 Japanese Patent Laid-Open No. 9-242025 Japanese Patent Laid-Open No. 2001-172977 JP 2001-234519 A

  In a protective fence or fallen rock prevention fence using thinned wood, a net fence with a preset volume is constructed taking into account the porosity when thinned wood is accommodated, and even when thin wood of different sizes is accommodated, There has been no buffer material for civil engineering structures and rockfall prevention fences that can secure the buffer performance of the period and prevent variations in the buffer performance.

An object of the present invention is to provide a cushioning material for civil engineering structures, a rockfall prevention fence, and a method for constructing the same, which have solved the above problems.

  In order to achieve the above object, the present invention is configured as follows.

  According to a first aspect of the present invention, there is provided a mesh cage in which the mesh bodies of the front, back, left and right sides, and the bottom of the rectangular mesh are joined at the edge by a coil-shaped connecting metal fitting and an opening is provided on the top. A cushioning material for a civil engineering structure, characterized in that a plurality of thinned timber having substantially the same height as that of a net cage is inserted into a cage with a gap capable of buffering movement.

  A second invention is characterized in that, in the first invention, the front mesh body of the net cage is openable and closable in a double-spread type, a single-open type, or a detachable type.

  A third invention is characterized in that, in the first or second invention, hanging metal fittings are joined to the upper four corners of the cushioning material for a civil engineering structure.

  According to a fourth aspect of the present invention, there is provided a first rockfall protection wall body including a plurality of support columns standing on a retaining wall at an interval and a plurality of horizontal members spanned between adjacent support columns. The civil engineering structure cushioning material according to any one of the third to third inventions is fixed by a joining metal fitting.

  A fifth invention is characterized in that, in the fourth invention, a space is formed between the thinned material and the ground by supporting a lower part of the cushioning material for civil engineering structure with a steel mount.

  According to the sixth method of the present invention, the front net of the second invention is folded into a net that can be opened and closed, brought into the field, assembled on the mountain side of the rock fall protective wall of the fourth invention, and fixed to the rock fall protective wall. The front of the net fence is opened, thinned material is accommodated in the inside, and the front net is closed to constitute a cushioning material for civil engineering structures.

The present invention has the following effects.
(1) By securing the necessary number of thinned lumber in a net of a certain size, the optimal porosity for buffering the thinned lumber can be ensured even if the thinned lumber is large or small. It is possible to easily and reliably configure the cushioning material for civil engineering structures.
(2) Site workability is improved by putting thinned wood into the nets in advance and unitizing them. In addition, when thinned wood deteriorates, it can be easily replaced for each unit.

(3) Since the thinned timber is housed in the nets, the thinned timber will not be scattered even if a falling rock collides. For this reason, it is possible to construct a protective fence that vertically uses the cushioning material for civil engineering structures, and it can be installed even in a small space. Of course, inclined installation is also possible.

(4) Even in a rugged place where large heavy machinery does not enter, after folding net fences are brought to the site, assembled, fixed to a rockfall prevention fence, it is also possible to install with a certain thinning material from the front such as a double door. Is possible. At that time, the workability is inferior to bringing a netting unit with thinned wood, but it is better than bundling thinned wood with steel wire on site, and of course, buffering action is better than bundling with iron wire. Yes.
(5) Since the thinned wood does not contact the ground directly, the thinned wood does not corrode early.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  1 (a), (b), and (c) are schematic views of a rockfall prevention fence according to the present invention, FIG. 1 (a) is a front view seen from Tanigawa, and FIG. 1 (b) is a plan view of a gantry frame. The figure and the figure (c) are side views. In each figure, pillars 2 made of H-section steel are erected at a predetermined interval on a foundation 1 constructed by placing concrete on an inclined ground or the like, and made of H-section steel between adjacent pillars 2. A plurality of horizontal members 3 are spanned in the vertical direction, and these H-shaped steels are combined to form a rock fall protection wall body 4. A book is placed on the back (mountain side) of the rock fall protection wall body 4. The buffer material 5 for civil engineering structure which concerns on invention is installed, and the rock fall prevention fence 6 is installed.

  The details of the civil engineering structure cushioning material 5 will be described with reference to FIGS. The civil engineering structure cushioning material 5 is configured to accommodate a number of thinned materials 8 in a net fence 7 and to have a predetermined height (h) and a front and rear width (D). As shown in FIGS. 3 and 4, the net cage 7 has a front net body 10 a, a back net body 10 b, and a left side net so as to form a rectangular parallelepiped having a relatively short depth with respect to the lateral width. The body 10c, the right side net 10d, and the bottom net 10e are provided, and the end edges of each surface are connected to the corner wire 11 arranged along each side of the rectangular parallelepiped by the coil-shaped connecting metal 12. The upper surface 13 is open. The mesh cage 7 is configured as a mesh container having a predetermined volume by calculating in advance the length of each side of the rectangular parallelepiped shape.

  A metal mesh is a typical example of the material of the mesh body, but it may be a mesh body made of synthetic fiber, carbon fiber, or the like as long as it has sufficient strength. Further, the coil-shaped coupling metal 12 is also described as a representative example of a known coupling metal, and may have a configuration other than that illustrated.

  Since the upper surface 13 of the net fence 7 is open, a plurality of thinned materials 8 can be accommodated inside the open upper surface 13, and the accommodated thinned materials 8 are supported by the bottom surface net 10e and do not fall. Then, a predetermined number of thinning materials 8 are accommodated in advance in the net 7 to constitute a civil engineering structure cushioning material 5 unit.

  Further, in the present invention, the net fence 7 is configured so that the front surface can also be opened. In the example shown in FIG. 4, the front mesh body 10a is divided into a left and right front mesh body 10a-1 and a front right network body 10a-2 with a center part dividing line 14 as a boundary, and the left and right mesh bodies 10a-1 are separated. 2 can be opened and closed by a double door system with the corner wire 11 in the vertical direction on both sides of the front as a rotation axis.

  In a rugged place where large heavy machinery does not enter, the net fence 7 is folded and brought to the construction site, assembled on the mountain side of the rock fall protection wall body 4, and a plurality of wire stops 15 (see FIG. It is also possible to install the thin netting material 8 from the open front of the net fence so as to close the front net body after it is fixed. In this case, the workability is inferior to bringing a net fence unit with thinned wood 8 but it is superior to the conventional method of binding the thinned wood 8 with iron wire at the site, and of course, the buffering action is also Better than unity. When the front left and right side nets 10 a-1 and 2 are closed, the joints are connected and closed using the coil-shaped connecting fitting 12.

  The openable front mesh body 10a may be a single-opening method instead of the kannon-type opening / closing method. In this case, the opening / closing frontal mesh body 10a is configured to be opened and closed with the vertical corner wire 11 on one side of the front surface as a rotation axis. Further, the front mesh body 10a may be configured to be detachable. In any case, the thinned material 8 can be accommodated from the front of the net fence 7, and it is excellent in workability in a steep place where a large heavy machine does not enter.

  It is desirable that the thinning material 8 accommodated in the net fence 7 has an optimum porosity for the thinning material 8 to buffer and move. Specifically, the plurality of screens 7 are accommodated so that the average porosity is about 50% to 55%. In this case, it is possible to ensure a predetermined porosity by simply storing a predetermined number of thinned lumber 8 having a large and small diameter, and this is possible because the volume of the net 7 is known in advance. This is because the number of thinned wood 8 accommodated in order to secure the desired porosity is known by the sampling method based on random sampling of the thinned wood 8 described below.

  The number of thinned timber 8 by the sampling method is determined as follows. For example, the porosity when removing an arbitrary number of thinned wood 8 as a sample from a pile of many thinned wood 8 of different diameters and placing it in a container (such as a net fence) where the volume is known (In particular, 50% to 55%) and the number of thinned wood 8 at that time is examined. By repeating this multiple times, it can be seen how many thinnings 8 randomly selected will be the desired porosity (50% to 55%) when accommodated in the net 7. It is only necessary to count the number of the thinned wood 8 and store it in the net fence 7 whose volume is mechanically known, thereby ensuring the desired porosity and accommodating the thinned wood 8 in the net fence 7.

  In a place where a rock fall prevention fence 6 can be constructed using a large heavy machine, a cushioning material 5 for civil engineering structure, which is configured in advance as a unit, is used. When the civil engineering structure cushioning material 5 is configured as a unit, the thinning material 8 should be housed in the net fence 7 at a primary processing plant such as a sawmill near the forest. As soon as the work of cutting to a predetermined size and cutting off the remaining twigs, etc. is completed, it is carried out as a flow work and constitutes a unit of the cushioning material 5 for civil engineering structure. This unit is then transported to the construction site by truck. At the site, the unit for the civil engineering structure cushioning material 5 is lifted using a heavy machine such as a crane and installed on the fall protection wall 4 constructed previously. By doing so, construction work of the civil engineering structure cushioning material 5 proceeds quickly.

  As shown in FIG. 5, hooks 16 are attached to the upper four corners of the civil engineering structure cushioning material 5 for lifting the unit of the civil engineering structure cushioning material 5. A wire 18 having a predetermined length is connected to the four corners of the hanging metal fitting 17 made of a rectangular frame. Therefore, by lifting the suspension fitting 17 with a heavy machine such as a crane, the civil engineering structure cushioning material 5 having a relatively heavy weight can be lifted smoothly without causing deformation and moved to a predetermined installation location.

  FIGS. 6 to 8 show structures for supporting and fixing the cushioning material 5 for the civil engineering structure to the rock fall protection wall body 4, and will be described in order. A pedestal 19 is installed on the lower end of the rock fall prevention fence 6 on the mountain side and on the upper surface of the concrete foundation 1. The mount 19 supports the bottom surface of the net fence 7 by floating from the ground 1a at a predetermined height so that rainwater and moisture do not penetrate into the lower end of the thinned wood 8 and corrode. It is configured.

  In the gantry 19 shown in FIG. 7, a plurality of support members 20 made of square steel pipes or the like that support the bottom surface of the reed 7 are arranged in parallel at predetermined intervals, and the support members 20 are arranged at predetermined intervals in the longitudinal direction. The connecting plate 21 is connected, and the connecting plate 21 is supported by a support leg 22 at a predetermined height. The support leg 22 is formed by welding the upper and lower portions of the both side angle members 22a and 22b with the upper angle member 22c and the lower angle member 22d, and the support member 20 is welded to the upper end of the support leg 22. Yes. A reinforcing angle member 22e is welded to the front angle member 22a.

  Therefore, since the lower end of the net fence 7 containing the thinned wood 8 is supported by the gantry 19, it does not contact the ground 1a, drains well and has good ventilation, so there is no risk of early corrosion, Durability can be maintained and used for a long time.

  In order to vertically support and fix the net fence 7 (cushioning material 5 for civil engineering structure) containing the thinned material 8 on the rock fall protection wall body 4, the horizontal frame 3 of the rock fall protection wall body 4 is provided at predetermined intervals. A fixing plate 23 having a T-shaped cross section is screwed to an end portion of a restraining steel wire 24 that restrains the front surface of the reed 7 and extends in the lateral direction. That is, as shown in FIGS. 8B and 8C as a view taken along the line B-B in FIG. 6, the H shape at the portion where the substrate 23 a of the T-shaped fixing plate 23 crosses the horizontal member 3. The bolts 25 are joined to the front flange of the steel support 2. Then, the end portion of the restraining steel wire 24 that restrains the front surface of the net cage 7 and extends in the lateral direction is inserted into the opening portion of the support arm 23b projecting forward of the fixing plate 23, and the thread portion of the projecting end The nut 26 is fastened and fixed, so that the civil engineering structure cushioning material 5 can be firmly fixed to the rock fall protection wall 4. The ends of the restraining steel wires 24 extending from the left and right are supported by a common support arm 23b, and are fastened by nuts 26 with their positions shifted from each other so as not to collide with each other.

  The present invention may be implemented by appropriately changing the design of the configuration shown in the embodiment. For example, the rock fall prevention wall body is inclined to the valley side, the back surface is supported by the support material from the valley side, and the buffer member 5 for the civil engineering structure is inclined and supported by the inclined rock fall prevention wall body. May be.

  The operation of the embodiment is summarized as follows.

(1) By securing the necessary number of thinned lumber in a net of a certain size, the optimal porosity for buffering the thinned lumber can be ensured even if the thinned lumber is large or small. It is possible to easily and reliably configure the cushioning material for civil engineering structures.
(2) Site workability is improved by putting thinned wood into the nets in advance and unitizing them. In addition, when thinned wood deteriorates, it can be easily replaced for each unit.

(3) Since the thinned timber is housed in the nets, the thinned timber will not be scattered even if a falling rock collides. For this reason, it is possible to construct a protective fence that vertically uses the cushioning material for civil engineering structures, and it can be installed even in a small space. Of course, inclined installation is also possible.

(4) Even in a rugged place where large heavy machinery does not enter, after folding net fences are brought to the site, assembled, fixed to a rockfall prevention fence, it is also possible to install with a certain thinning material from the front such as a double door. Is possible. At that time, the workability is inferior to bringing a netting unit with thinned wood, but it is better than bundling thinned wood with steel wire on site, and of course, buffering action is better than bundling with iron wire. Yes.
(5) Since the thinned wood does not contact the ground directly, the thinned wood does not corrode early.

(A), (b), (c) is the outline | summary front view, outline | summary top view, and outline | summary side view of the rock fall prevention fence which concern on embodiment. (A) is the top view which attached the net fence of the buffer material for civil engineering structures to the fall protection wall, (b) is a side view. FIG. 3 is a detailed view of FIG. (A) is a development view of a net cage, (b) is an assembled perspective view. It is a perspective view which shows the attachment aspect of the hanging metal fitting which lifts the net fence which accommodated the thinned material. It is a side view of the falling rock protection wall which attaches the buffer material for civil engineering structures. (A) is a side view of a gantry supporting a net cage, and (b) and (c) are a CC arrow view and a DD arrow view of FIG. (A), (b) is the AA arrow directional view and BB arrow directional view of FIG. 6, (c) is an enlarged view of the E section of FIG.8 (b).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Concrete foundation 2 Support | pillar 3 Horizontal member 4 Falling rock protection wall body 5 Cushioning material for civil engineering structure 6 Falling rock prevention fence 7 Net fence 8 Thinning material 10a Front net body 10b Back surface net body 10c Left side net body 10d Right side net body 10e Bottom network 11 Corner wire 12 Coiled metal 13 Upper surface 14 Center parting line 15 No. wire stop 16 Hook 17 Suspension metal 18 Wire 19 Mounting base 20 Support base 21 Connecting plate 22 Support leg 22a Front side angle material 22b Rear side angle material 22c Upper angle material 22d Lower angle material 22e Reinforcement angle material 23 Fixing plate 23a Substrate 23b Support arm 24 Retaining steel wire 25 Bolt 26 Nut

Claims (6)

The front, back, left and right side surfaces, and the bottom of the rectangular parallelepiped net are connected by a coil-like connecting bracket at the edge, and the net having an opening on the upper surface, and the net in the net A cushioning material for a civil engineering structure, wherein a plurality of thinned materials having substantially the same height are inserted with a gap capable of buffering movement. 2. The cushioning material for a civil engineering structure according to claim 1, wherein a front mesh body of the net cage is openable and closable in a double-spread type, a single-open type, or a detachable type. The falling rock prevention fence according to claim 1 or 2, wherein a hanging metal fitting is joined to the upper four corners of the cushioning material for civil engineering structure. Any one of claims 1 to 3 on a rock fall protective wall body comprising a plurality of columns erected on the foundation ground at intervals and a plurality of horizontal members spanned between adjacent columns. A rock fall prevention fence characterized in that the cushioning material for civil engineering structure according to item 1 is fixed by a joining metal fitting. The rock fall prevention fence according to claim 4, wherein a space is formed between the thinned material and the ground by supporting a lower part of the cushioning material for civil engineering structure with a steel mount. The front net body according to claim 2 is folded into a net that can be opened and closed, brought into the field, assembled on the mountain side of the rock fall protection wall body according to claim 4, and fixed to the rock fall protection wall body, and then the front face of the net fence is opened. A method for constructing a rock fall prevention fence, characterized in that a thinning material is accommodated therein and a front mesh body is closed to constitute a cushioning material for a civil engineering structure.

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