JP2013159895A - Disaster prevention system for tsunami - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide measures against tsunami that can be structured early.SOLUTION: There is provided a disaster prevention system for tsunami characterized by installing a guard fence 10 for tsunami in a predicted area that tsunami passes through, the guard fence 10 including: a plurality of columns 12-1 to 12-n stood on a ground surface at predetermined intervals in a direction substantially orthogonal to a predicted direction in which waves flow at occurrence of tsunami; and a high-strength net body 14 supported and stretched by the plurality of columns 12-1 to 12-n.

Description

  The present invention relates to a disaster prevention system for tsunami that can be constructed at an early stage.

  Tsunamis caused by earthquakes, landslides, etc. are natural disasters that cause tremendous physical or human damage, so the construction of seawalls, breakwaters, etc., and the relocation of houses to high grounds, etc. Various tsunami countermeasures have been taken. In addition to this, tsunami countermeasures have been carried out by placing a tide forest on or near the coast.

  Although there is no ability to dam the tsunami that hits like a structure such as a seawall or breakwater, there is no ability to block a tsunami in the past. It has been reported that buildings such as private houses on the land side escaped damage or suffered less damage.

Disaster prevention park technology handbook continued, author: Urban Greening Technology Development Organization

  However, once a tide forest is damaged and falls down or decays, it takes a long period of decades to grow the tree to a certain height and return its roots to the ground to restore its original state. On the other hand, even in places where there were originally no tide forests, the number of areas that need tsunami countermeasures has increased significantly due to damage caused by past tsunamis, and it is not possible to predict when earthquakes that cause tsunamis will occur. Tsunami countermeasures that can be built in the future are required.

  Therefore, an object of the present invention is to provide a tsunami countermeasure that can be established early.

  In order to solve the above-mentioned problem, the disaster prevention system for tsunami according to claim 1 is provided with a plurality of erected on the ground lined up at predetermined intervals in a direction substantially orthogonal to a predicted wave flow direction at the time of tsunami occurrence. An anti-tsunami guard fence having a support and a high-strength net supported and supported by the plurality of support is installed in an area where a tsunami is expected to pass.

  According to this configuration, the water level of the tsunami after passing through the tsunami can be lowered by a high-strength network, and drifting objects (automobiles, ships, collapsed houses, etc.) caused by the tsunami can be captured. It is possible to reduce damage to buildings and human damage located on the land side of the protective fence. In addition, because the net is used, the tsunami can be visually inspected, and the evacuation of neighboring residents can be avoided. The anti-tsunami guard fence has a simple structure with a net supported on a support and can be installed in a short period of time, and tsunami countermeasures can be taken early.

  The anti-tsunami disaster prevention system according to claim 2, wherein the anti-tsunami guard fence is fixed to the ground on both sides of the flow direction of the wave with respect to the support, the upper part of the support and the And a traction member for connecting the anchor.

  According to this configuration, since the struts are erected firmly, it becomes a tsunami protection fence with high resistance and durability against tsunami, and can take effective tsunami countermeasures for a long time. Further, by stretching the traction material from the upper part of the support to both the sea side and the land side, the effect can be exhibited not only for the push wave but also for the pull wave.

  The disaster prevention system for anti-tsunami according to claim 3, wherein the traction member is provided with a buffer member that cushions an impact force caused by the tsunami, and the support column is erected so as to be tiltable in the wave flow direction. Features.

  According to this configuration, when a considerable load is applied to the anti-tsunami guard fence due to the tsunami and its drifting objects, if the force that tilts the column to the side opposite to the side that received the tsunami acts, the force is pulled. Transmitted to the material. Then, the force transmitted to the traction member is buffered by the buffer member, whereby the tilting operation of the tiltable column is performed. Thereafter, when the limit of the buffering action of the buffer member is reached, the struts are maintained in a constant inclination state by the tension of the traction material, and the drifting object is reliably captured by the net.

  The anti-tsunami disaster prevention system according to claim 4 is characterized in that a scouring prevention body that covers at least the ground of the strut installation area in the area where the anti-tsunami protection fence is installed is installed.

  According to this configuration, it is possible to prevent the earth and sand on the ground where the protective fence is installed from being washed away and eroded by the tsunami. Therefore, it is possible to improve the stability and reliability of the installation state of the support column and further the installation state of the fence.

  The anti-tsunami disaster prevention system according to claim 5 is characterized in that, when there is already a tidal forest, the anti-tsunami protection fence is installed at a position adjacent to the tidal forest.

  According to this configuration, an effective anti-tsunami disaster prevention system can be constructed by combining the tide forest and the anti-tsunami protection fence.

  The anti-tsunami disaster prevention system according to claim 6 is characterized in that a plurality of the anti-tsunami protection fences are installed on the predicted wave path.

  According to this configuration, since the water level of the tsunami can be lowered step by step by the plurality of protective fences, it is possible to cope with a large tsunami.

  According to the anti-tsunami disaster prevention system of the present invention, it is possible to capture drifting objects caused by a tsunami and to reduce the water level of the tsunami after passing through the tsunami, thereby reducing damage to buildings and human damage. be able to. Since the anti-tsunami guard fence has a simple structure in which a net is supported on a support, it can be installed in a short period of time, and tsunami countermeasures can be taken early.

It is a front view which shows an example of the protection fence for anti-tsunami. It is a side view of the anti-tsunami protection fence shown in FIG. It is detail drawing of the lower part of a support | pillar. It is explanatory drawing which shows an example of a net body. It is a detailed view of a hard steel wire. It is explanatory drawing which shows an example of a net body. It is explanatory drawing of a ring-type net | network. It is explanatory drawing of a buffer member. It is explanatory drawing which shows the example of installation of the protection fence for anti-tsunami. It is explanatory drawing which shows the effect of the disaster prevention system for anti-tsunami of this invention.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view showing an example of an anti-tsunami protection fence used in the anti-tsunami disaster prevention system of the present invention, and FIG. 2 is a side view thereof. As shown in the drawing, a plurality of support columns 12-1 to 12-n are erected at a predetermined interval over a required length range to form one support column, and each support column 12 forms a net 14. Supported and stretched. Each support column is erected on the ground in a predetermined interval in a direction substantially orthogonal to the predicted wave flow direction when a tsunami occurs. In the present invention, the side that receives the tsunami wave is called the “sea side”, and the opposite side is called the “land side”.

  The net 14 is stretched by being connected to the upper support rope 16 and the lower support rope 18. The upper support rope 16 is stretched from the upper support rope first anchor 20-1 fixed to the ground to the upper support rope second anchor 20-2 through the upper portions of the respective pillars 12-1 to 12-n. ing. Similarly, the lower support rope 18 is also connected to the lower support rope second anchor 22-1 from the lower support rope first anchor 22-1 fixed on the ground through the lower portions of the columns 12-1 to 12 -n. -2 is stretched. Further, lateral ropes 24 connecting the upper portions of the struts 12-1 and 12-n at both ends and the lower support rope anchors 22-1 and 22-2 are also stretched, respectively. The overall strength is improved.

  Each column 12-1 to 12-n is erected on the ground 100 through the foundation 26. The foundation 26 is made of concrete, and a base member 28 is installed on the foundation 26 as shown in FIG. A rib 30 is provided on the base member 28, and the rib 30 and the lower part of the support column 12 are hinged to each other. As a result, the support column 12 is fixed to be tiltable in the tsunami flow direction (arrow direction). . In addition, a hole (not shown) is formed in the base member 28, and two anchors 34 are inserted through the base 26 through the hole 26 so that the support column 12 takes a reaction force against the ground. Thus, the column 12 and the foundation 26 are integrally fixed.

  The height of the support columns 12 is 3 to 6 m, and the installation interval is about 5 to 10 m, which are appropriately selected. The installation side of the net body 14 with respect to the support 12 may be the sea side or the land side. Moreover, although the four support | pillars 12-1 to 12-n are illustrated in this example, you may change the number of support | pillars suitably. The length of the protective fence 10 in the extending direction is, for example, 5 to 60 m.

The mesh body 14 is of high strength and can catch drifting objects (building materials for buildings, automobiles, ships, daily necessities, etc.) caused by a tsunami and reduce the water level of the tsunami after passing through the mesh body. It is. As such a net body, a net having a rhombus shape or a ring shape can be used as shown in FIGS. Such a net body is composed of a hard steel wire, and the hard steel wire was produced by twisting a plurality of steel wires (diameter 2 mm to 5 mm) (for example, 2 to 5 wires). A stranded wire (diameter 6-15 mm) can be used. A hard steel wire having a tensile strength of 400 to 2000 N / mm ² is particularly used.

  The rhombus net shown in FIG. 4 is a net having a rhombus opening. As shown in the figure, a diamond wire mesh is formed by the hard steel wire 40. The size of the rhombus is such that the vertical length of the diagonal is 20 cm to 60 cm and the horizontal length of the diagonal is about 15 cm to 30 cm, and the diameter of the inscribed circle of the rhombus is 10 to 30 mm. FIG. 5 shows a detailed view of the hard steel wire 40. As shown, a hard steel wire 40 is formed by twisting three strands 41.

  In addition, a ring-type net can be used as the net body 14. For example, FIG. 6 is a perspective view showing a ring-shaped member used for a ring-type net, which is formed by winding a hard steel wire from one to a plurality of times and tightening several places in the circumferential direction by fastening means 42a. The fastening means 42a is, for example, a substantially cylindrical metal fitting having a C-shaped cross section, and after being fitted to the wire bundle through the opening, it is fixed to the wire bundle by a tightening tool. In addition, it is possible to adjust the intensity | strength of a ring net and the below-mentioned energy absorption power by adjusting the thickness and the number of turns of a wire.

  As shown in FIG. 7A, each ring-shaped member 42 is configured to be connected to four surrounding ring-shaped members. In addition to this configuration, one ring-shaped member 42 may be configured to be connected to each of six ring-shaped members, as shown in FIG. The ring-shaped members 42 are connected to each other as shown in FIGS. 7A and 7B. The connection may be performed by using an appropriate connection member in addition to such an intersection.

  It is preferable that the hard steel wire constituting the rhombus-shaped mesh body or the ring-type net is subjected to anticorrosion treatment, and for example, zinc plating, aluminum zinc alloy plating, or resin coating is performed. Examples of the resin used include polypropylene, polyethylene, and vinyl chloride. The anticorrosion treatment may be a twisted wire after coating each of the above-described strands, or the strand that has not been subjected to the anticorrosion treatment may be a twisted wire, and then the twisted wire may be coated.

  Such a high-strength mesh body has strong resistance to capture automobiles, collapsed houses, ships, etc. that are drifting due to tsunami, and can reduce the water level of the tsunami after passing through the mesh body. , Can reduce the damage.

  Moreover, the dimension of the opening part of such a net | network body can be suitably selected according to the place which installs a guard fence, topography, the magnitude | size of the estimated tsunami etc. For example, when the anti-tsunami protection fence 10 is installed in a place closer to the sea, a net having a large opening can be used because the object to be captured is mainly a ship. On the other hand, when the anti-tsunami guard fence 10 is installed in a place where there are many buildings in the surrounding area, a mesh body with a small opening is selected so that building materials and household items of the collapsed building can be captured. be able to.

  In the example shown above, the net body 14 is an example of an anti-tsunami protective fence in which a single net body is stretched continuously from the post 12-1 at one end to the post 12-n at the other end. Although shown, a plurality of nets can be separately stretched between the columns.

  As shown in FIG. 2, anchors 50 are fixed to the ground on both sides in the wave flow direction predicted with reference to the support 12, that is, the ground on the sea side and the land, respectively. Connecting members 52 for connecting the upper portions of the twelve portions are provided. As a result, the support column 12 is firmly erected and held on the ground 100, and the degree of tilting operation of the support column 12 is adjusted. As the traction material 52, a wire rope, a steel rod, a chain, a PC steel material, or the like can be used. In FIG. 1, the traction member 52 and its anchor 50 are not shown.

  As shown in FIG. 1 and FIG. 2, a buffer member 60 is provided in the middle of the traction material 52 and the upper support rope 16 and the lower support rope 18. The support ropes 16 and 18 act to absorb a part of the energy of drifting objects and tsunami that act as tension. When the pulling member 52 is a wire rope, the specific structure of the buffer member is composed of a loop pipe 62a and a fastening member 62b as shown in FIG. 8, and a midway portion of the pulling member 52 is inserted into the loop pipe 62a. Has been. Both ends of the loop tube 62a are overlapped in parallel, and the overlapping portion is tightened by the tightening member 62b. Therefore, the loop tube 62a is in frictional contact with each other in the overlapping portion, and between the loop tube 62a and the tightening member 62b. Also in this case, frictional contact is made. The loop pipe 62a is preferably a steel pipe, but may be made of other metal material or plastic material. Moreover, you may change suitably the number which installs the buffer member 60. FIG. For example, it is 1-5, and when providing a plurality, it can install in series or in parallel.

  When the traction force is exerted on the traction member 52 and a large tension force is generated on the traction member 52, a force to reduce the diameter of the loop tube 62a is applied, and both ends of the loop tube 62a are along the traction member 52. Receives forces in opposite directions. When the tension force applied to the traction member 52 exceeds the friction force between the loop tubes and the loop tube 62a and the tightening member 62b at the tightening point, slip occurs between them, and a friction resistance force is provided. Further, a resistance force is generated when the diameter of the loop tube 62a is further reduced. By these resistance forces, the kinetic energy caused by the tsunami water flow and drifting material received by the traction material 52 is absorbed. By selecting the diameter of the loop tube 52a, the wall thickness of the tube, and the constituent material, the energy absorption capacity can be changed in various ways, and various requirements can be easily met. Further, in the illustrated example, the loop tube 52a has one turn, but may have a double turn or more turns.

  And according to such a buffer member 60, when a load is applied to the anti-tsunami protection fence 10 by the tsunami and its drifting object, a force that tilts the column to the side opposite to the side that received the tsunami acts. The force is transmitted to the traction member 52. Then, the force transmitted to the traction member 52 is buffered by the buffer member 60, whereby the tilting operation of the tiltable support column 12 is performed. After that, when the limit of the buffering action of the buffer member 60 is reached, the strut 12 is maintained in a constant inclination state by the tension of the traction member 52, and the drifting object is reliably captured by the net body 14.

  As shown in FIGS. 1 and 2, the ground near the installation location of the protective fence 10 is provided with scouring prevention bodies 36 on the land side and the sea side, respectively. This scouring prevention body 36 is configured by arranging a plurality of plate-like concrete members 36a having a thickness of 10 to 30 cm and arranged in the ground, and the scouring prevention body 36 as a whole is directed outward from the column 12 side. It is buried so as to be deep and deep. Each plate-like concrete member 36a is mutually connected by connection materials, such as a wire which is not illustrated. The entire width of the scouring prevention body 36 is longer than the lateral length, and the outermost depth is about 1 to 5 m. Such a scouring prevention body 36 can be installed by excavating the ground in which the scouring prevention body 36 is buried, placing a plate-like concrete member, and then returning the earth and sand.

  In this example, an example is shown in which the scouring prevention body 36 is installed over the entire column of columns, but the scouring prevention body is the ground in at least the column 12 installation region in the region where the anti-tsunami protection fence 10 is installed. The structure which covers may be sufficient. By providing the scouring prevention body 36, it is possible to take a disaster prevention system for tsunami using a protection fence for tsunami that is firmly fixed even in an area where the ground is poor.

  Hereinafter, the installation location of the anti-tsunami protection fence 10 will be described. FIG. 9 is an explanatory view showing an installation example of a protection fence for tsunami. This figure shows an example in which an anti-tsunami protection system is provided in an area where the sea 300 and the river 200 are located, and a seawall 250 is built on the coast.

  The anti-tsunami guard fence 10 is in a region where a tsunami is predicted to pass so that a column of the plurality of columns 12 extends in a direction substantially orthogonal to the predicted wave flow direction when the tsunami occurs. Installed. For example, in the vicinity of the estuary (reference numeral 206), in the vicinity of the coast (reference numeral 202), in the vicinity of the river (reference numeral 204), in the vicinity of the river where the tsunami goes up (reference numeral 204), in parallel with the extending direction of the river. Change the position of the struts appropriately according to the predicted tsunami, such as installing them diagonally. The route of the tsunami can be predicted by the land topography, the layout of buildings, the sea level, roads, and so on.

  In addition, as shown in the figure, when there is a tide forest 150 already, it can be installed in the vicinity of the tide forest 150 and sufficient tsunami countermeasures can be taken together with the tide forest 150. In the illustrated example, the anti-tsunami protection fence 10 is installed on a path where a tsunami between two tide forests 150 is predicted to flow. In addition, when there is a tide forest 151 that has disappeared due to the collapse of a past tsunami, for example, a tsunami protection fence 10 is installed at or near the location to wait for the growth of a new tide forest. Tsunami countermeasures can be taken as soon as possible. Furthermore, in the anti-tsunami disaster prevention system according to the present invention, the anti-tsunami protection fence 10 is installed at a plurality of locations so as to overlap the predicted tsunami flow path, thereby further improving the drifting object capturing / tsunami attenuation effect. . Moreover, you may install the protection fence for anti-tsunami in a residential area etc. in the range which does not interfere with the passage of a person or a vehicle. In addition, for example, when installing a plurality of anti-tsunami protection fences along the coast and over a long distance, leave a space of about 2 to 3 m so as not to hinder the passage of refugees. It is also suitable to juxtapose.

  FIG. 10 is an explanatory diagram showing the effect of the anti-tsunami disaster prevention system of the present invention. As shown in the figure, the tsunami 500 over the seawall 301 flows along with the drifting object 400 toward the land, but after passing through the anti-tsunami protection fence 10, the water level decreases as shown by the broken line. The drifting object is captured by the anti-tsunami guard fence 10. When the drifting object collides with the tsunami protection fence 10, as shown by the broken line in FIG. 2, the net body 14 bulges and deforms in the direction opposite to the tsunami receiving side, and receives the drifting object. Further, as described above, the anti-tsunami protection fence 10 can also capture the drifting substance 401 caused by the pulling wave, and can prevent the drifting substance from flowing out to the ocean.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made.

DESCRIPTION OF SYMBOLS 10 Anti-tsunami protection fence 12 Support | pillar 14 Net body 16 Upper support rope 18 Lower support rope 20-1 Upper support rope first anchor 20-2 Upper support rope second anchor 22-1 Lower support rope first Anchor 22-2 Second support rope for lower support rope 24 Lateral rope 26 Base 28 Base member 30 Rib 34 Support anchor 36 Scouring prevention body 40 Hard steel wire 42 Ring-shaped member 50 Traction material anchor 52 Retraction material 60 Buffer member 200 River 300 Sea 301 Seawall 500 Tsunami

Claims (6)

  A plurality of struts erected on the ground in a direction substantially orthogonal to the predicted wave flow direction at the time of tsunami occurrence, and a high-strength network supported and stretched by the plurality of struts An anti-tsunami disaster prevention system, characterized in that an anti-tsunami protection fence having a tsunami is installed in an area where a tsunami is expected to pass. The protective fence for the tsunami is
Anchors respectively fixed to the ground on both sides of the wave flow direction with respect to the support column,
A traction material for connecting the upper portion of the column and the anchor;
The anti-tsunami disaster prevention system according to claim 1, wherein The traction material is provided with a buffer member that cushions the impact force caused by the tsunami,
The anti-tsunami disaster prevention system according to claim 2, wherein the support column is installed to be tiltable in the wave flow direction.   The anti-tsunami according to any one of claims 1 to 3, further comprising a scouring prevention body that covers at least the ground of the support installation area in an area where the anti-tsunami protection fence is installed. Disaster prevention system.   The anti-tsunami disaster prevention system according to any one of claims 1 to 4, wherein the anti-tsunami protection fence is installed at a position adjacent to the anti-tide forest when there is already a tidal forest.   The anti-tsunami disaster prevention system according to any one of claims 1 to 5, wherein a plurality of the anti-tsunami protection fences are installed so as to overlap a predicted wave flow path.

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