JP2017009587A - Wave-making device and wave-making method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wave-making device and a wave-making method capable of reproducing a wave close to an actual tsunami by continuously making a wave having a rising waveform of the top end portion of the tsunami waveform and a wave having a long frequency.SOLUTION: An measurement object 8 and a water storage part 3 are arranged at an interval from each other in a water tank 2. A partition plate 4 constituting a surface on the side of the measurement object 8 of the water storage tank 3 is moved upward, and water W in the water storage part 3 is let flow toward the measurement object 8, thereby generating a wave T. The flowing out water W is made to circulate in the water storage tank 3, and the wave height of the wave T is detected by a wave height sensor 7 between the partition plate 4 and the measurement object 8, and a water level of the water storage tank 3 is detected by a water level gauge 14. The movement of the partition plate 4 is controlled by a control part 6 based on these detection data and the previously determined data, and the partition plate 4 is vertically moved by a movement mechanism 5. The wave T approximated to the waveform data predetermined by sequentially continuing the control of the opening height by the control part 6 is reproduced.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wave making apparatus and a wave making method. More specifically, the present invention relates to a wave forming device that continuously forms a rising waveform (step wave) and a long period wave (long period wave) at the tip of a tsunami waveform, The present invention relates to a wave making apparatus and a wave making method capable of reproducing a wave close to a tsunami.

  Most of the causes of tsunamis are caused by submarine earthquakes in the sea area, and on the horizontal scale, a sea level displacement of several meters occurs in the range of tens to 100 km and propagates throughout the sea area. Therefore, the period of the tsunami is very long, from several minutes to several tens of minutes. When the tip of the tsunami reaches the shallow sea area, the wave height increases rapidly and a step wave is generated at the tip.

  Conventionally, when performing a hydraulic experiment for a tsunami, a piston-type or pump-type wave making device has been used (see, for example, Patent Document 1). However, in the conventional wave making device, it is difficult to simultaneously reproduce the rising waveform at the tip of the tsunami waveform and the long-period wave. For example, in the piston type, the wave plate is moved by a long period to generate waves. However, when reproducing a wave with a large wave height such as a tsunami, it is necessary to move the wave plate over a long distance. Facility is necessary. Therefore, hydraulic experiments were made only for the rising waveform at the tip of the tsunami waveform by creating a sine wave or solitary wave with a long period.

  The pump type can make long-period waves, but it is difficult to make a waveform that rises rapidly due to the characteristics of the pump. Requires a large capacity pump. Thus, since the conventional wave-making method requires a large-scale facility to reproduce a wave close to a tsunami, it is difficult to perform a hydraulic experiment by reproducing a wave close to a tsunami. Therefore, a wave making apparatus and a wave making method that can reproduce a wave close to a tsunami without requiring a large-scale facility have been desired.

JP2013-181869A

  The object of the present invention is to continuously create a rising waveform (step wave) at the tip of a tsunami waveform and a long-period wave (long-period wave) to reproduce a wave close to an actual tsunami. It is in providing an apparatus and a wave making method.

  In order to achieve the above object, a wave making apparatus of the present invention is installed in a water tank in which a measurement object is disposed, and in the water tank with a space in the longitudinal direction of the water tank with respect to the measurement object. A water storage section, a partition plate forming a surface of the water storage section on the object side to be measured, and a moving mechanism for moving the partition plate up and down. In the wave generator for generating a wave by the water in the water storage part that has flowed out toward the measurement object from the measurement object side, circulation means for circulating the discharged water to the water storage part, A control unit that controls the vertical movement of the partition plate; and a wave height sensor that detects a wave height of the wave between the partition plate and the measurement object, the detection data by the wave height sensor and predetermined waveform data Based on By controlling the vertical movement of the partition plate have, inside the water tub by the drained water, characterized in that to generate a wave having a waveform approximated to the waveform data previously determined.

  In the wave making method of the present invention, a measuring object and a water storage part are arranged inside the water tank with an interval in the longitudinal direction of the water tank, and a partition plate constituting the surface of the water storage part on the side of the measuring object is provided. A wave-making method in which the measurement object side of the water storage unit is opened by causing the water storage unit to move upward so that water in the water storage unit flows out toward the measurement object, and waves are generated by the discharged water. In this case, the effluent water is circulated to the water reservoir, and the wave height is detected by a wave height sensor between the partition plate and the measurement object, and the detected data and the predetermined waveform data are Based on this, the vertical movement of the partition plate is controlled to generate a wave having a waveform approximated to the predetermined waveform data by the discharged water.

  According to the present invention, the water that has flowed out from the water reservoir toward the object to be measured inside the water tank is circulated through the water reservoir, so that the water can be continuously discharged toward the object to be measured. Then, the wave height sensor detects the wave height between the partition plate and the measurement object, and the vertical movement of the partition plate is controlled based on the detection data and the predetermined waveform data. If used, it not only generates waves with various wavelengths, periods, and wave heights, but also continuously creates rising waveforms (step waves) and long-period waves (long-period waves) at the tip of the tsunami waveform, A wave close to the actual tsunami can be reproduced.

  In the present invention, the water tank is formed in a double bottom surface structure having an upper bottom surface and a lower bottom surface, the measurement object and the water storage section are disposed on the upper bottom surface, and between the upper bottom surface and the lower bottom surface. The formed water storage part and the communication part which penetrates up and down formed in the longitudinal direction both ends of the upper bottom face are provided, and the water that has flowed into the water storage part through the communication part is circulated to the water storage part by the circulation means. You can also. In this case, since the water that has flowed out of the water storage part appropriately flows into the water storage part through the communication part, the amount of water present on the upper bottom surface is optimized without excess or deficiency. Therefore, water can be circulated stably and continuously.

  When water in the water storage part flows out toward the measurement object in a state where water of a predetermined water level exists between the measurement object inside the water tank and the partition plate, a tsunami at sea is reproduced. be able to. Reproducing a tsunami flooding on land when water in the water storage part flows out toward the measurement object in a state where no water exists between the measurement object inside the water tank and the partition plate Can do.

  It can also be set as the structure which maintains the water level of a water storage part constant. With this configuration, since the water pressure of the water to be discharged is constant, a stable wave can be generated.

  By making the water in the water reservoir overflow to the side facing the partition plate, the upper limit water level of the water reservoir can be maintained constant. With this configuration, the water level of the water storage section can be maintained constant with a very simple configuration.

  A water level meter that measures the water level of the water storage unit may be provided, and the vertical movement of the partition plate may be controlled based on detection data from the water level meter. With this configuration, even when the water level of the water storage section changes, it is possible to accurately generate a wave having a waveform that approximates the predetermined waveform data.

  The partition plate may be configured to be fixed at an arbitrary position in the longitudinal direction of the water tank by a frame with a rail with a bearing extending in the vertical direction and coming into contact with the partition plate. With this configuration, the partition plate can be stably fixed to the water tank while the wave-making distance can be arbitrarily set. In addition, the vertical movement of the partition plate can be performed smoothly and accurately.

  The water circulated through the water storage unit may be supplied to the partition plate side through a rectifying body provided in the water storage unit. With this configuration, it is possible to avoid giving waves or unnecessary disturbances caused by the flow of water circulated to the water storage unit to the water flowing out from the water storage unit toward the measurement object. Thereby, the wave which has the waveform approximated to the waveform data determined beforehand can be reproduced more accurately.

  It is also possible to adopt a configuration in which the wave that is pushed toward the downstream side in the outflow direction of the water that has flowed out of the measurement object is extinguished by the wave-dissipating body. With this configuration, it is possible to prevent a wave that exceeds the measurement object from being reflected and returned, so that a more accurate measurement result can be obtained without being affected by an unnecessary reflected wave.

  A movable weir is provided on the downstream side in the outflow direction of the water that has flowed out from the measurement object, and the water level stored between the measurement object and the movable weir can be changed by the movable weir. You can also With this configuration, it is possible to reproduce the situation inside the bank when the tsunami enters the breakwater.

It is explanatory drawing which illustrates embodiment of the wave generator of this invention by a water tank longitudinal direction sectional view. It is explanatory drawing which expanded the water storage part vicinity of FIG. It is explanatory drawing which illustrates the water tank of the wave generator of FIG. 1, and its internal state by planar view. It is explanatory drawing which illustrates typically the step wave and long-period wave which are generated in the state in which the water of a predetermined water level does not exist on an upper side bottom face with the wave generator of this invention in a water tank longitudinal cross-sectional view. It is explanatory drawing which illustrates another embodiment of the wave generator of this invention by a water tank longitudinal direction sectional view. It is explanatory drawing which illustrates the water tank and its internal state of the wave making apparatus of FIG. 5 by planar view. It is explanatory drawing which illustrates typically the step wave and long period wave which are generated in the state in which the water of a predetermined water level exists on an upper side bottom face with the wave generator of this invention by a water tank longitudinal cross-sectional view. It is explanatory drawing which illustrates further another embodiment of the wave generator of this invention by a tank longitudinal direction sectional view. It is explanatory drawing which illustrates further another embodiment of the wave generator of this invention by a tank longitudinal direction sectional view. It is explanatory drawing which illustrates typically the step wave generated with the conventional wave generator with a water tank longitudinal direction sectional view.

  Hereinafter, the wave making apparatus and method of the present invention will be described based on the embodiments shown in the drawings.

  The wave making device 1 of the present invention illustrated in FIGS. 1 to 3 configures a water tank 2 in which a measurement object 8 is disposed, a water storage unit 3 disposed in the water tank 2, and a side surface of the water storage unit 3. A partition plate 4 and a moving mechanism 5 that moves the partition plate 4 up and down are provided. The wave making device 1 further includes a control unit 6 that controls the vertical movement of the partition plate 4, a wave height sensor 7 in which detection data is input to the control unit 6, and water W that has flowed out of the water storage unit 3 again. 3 is provided with circulation means 9 for circulation. In the drawing, the longitudinal direction of the water tank 2 is indicated by an arrow X, and the width direction is indicated by an arrow Y.

  Furthermore, in this embodiment, a frame 10 that fixes the partition plate 4 to the water tank 2, a rail 11 with a bearing that is interposed between the frame 10 and the partition plate 4, and a rectifier 12 that is installed in the water storage unit 3, The wave-dissipating body 13 disposed in the water tank 2 and a water level meter 14 installed above the water storage unit 3 are provided. The water reservoir 3 is disposed at one end in the longitudinal direction of the water tank 2, and the measurement object 8 is disposed at the other end in the longitudinal direction of the water tank 2.

  The water tank 2 has a rectangular parallelepiped shape with an upper surface opened, and has a length of, for example, 10 to 100 m, a width of 0.3 to 2.0 m, and a height of about 0.5 to 2.0 m. The width dimension is constant and the bottom is horizontal. The side surface of the water tank 2 is formed of, for example, transparent glass, and is appropriately reinforced with a metal member.

  In this embodiment, the water tank 2 has a double bottom structure composed of an upper bottom surface 2a and a lower bottom surface 2b. The upper bottom surface 2a and the lower bottom surface 2b are horizontal to each other, and a water reservoir 2e is formed between them. Communication portions 2c and 2d penetrating vertically are provided at both longitudinal ends of the upper bottom surface 2a. A recessed portion 2f is provided at the other end in the longitudinal direction of the reservoir 2e (on the measurement object 8 side).

  The water storage unit 3 includes a partition plate 4 that extends the entire length in the width direction of the water tank 2, and a side plate 3 a that is opposed to the partition plate 4 and is disposed at intervals in the longitudinal direction of the water tank 2. The side plate 3 a extends upward from the upper bottom surface 2 a and extends the entire length in the width direction of the water tank 2. The partition plate 4 is disposed closer to the measurement object 8 than the side plate 3a. When the partition plate 4 moves downward, the lower end thereof comes into contact with the upper bottom surface 2a. A part of the longitudinal direction of the water tank 2 is partitioned by the partition plate 4 and the side plate 3a, and water W is stored between them. That is, when the water level exceeds a certain level, the water W overflows from the side plate 3a. The water storage capacity of the water storage unit 3 can be set arbitrarily.

  The height dimension of the partition plate 4 is set to be equal to or greater than the height dimension of the side plate 3a. By changing the height dimensions of the partition plate 4 and the side plate 3a, the water storage capacity of the water storage section 3 can be changed.

  As the moving mechanism 5, an actuator can be used. For example, an electric cylinder or a hydraulic cylinder is used. A plurality of moving mechanisms 5 can be provided.

  The frame 10 includes a frame structure outer frame 10c that forms a rectangular parallelepiped, a fixture 10d that fixes the outer frame frame 10c to the upper end of the water tank 2, and a flat plate-like resistance extending downward from the outer frame frame 10c. The hydraulic frame 10a and the support frame 10b that fixes the moving mechanism 5 to the outer frame 10c are configured. The water-resistant frame 10a is disposed opposite to the partition plate 4 and has a bearing-equipped rail 11 extending in the vertical direction. This rail 11 with a bearing contacts the partition plate 4 to guide the vertical movement of the partition plate 4.

  The width dimension of the water pressure resistant frame 10 a is substantially the same as the width dimension of the partition plate 4. The lower end position of the water pressure resistant frame 10a is set to a position higher than the upper end position of the opening height H1 (H2) described later of the partition plate 4.

  The non-movable part (cylinder) of the moving mechanism 5 is firmly fixed to the outer frame frame 10c by the support frame 10b. Thereby, the movable part (rod) of the moving mechanism 5 stably moves forward and backward, and the partition plate 4 moves up and down accordingly.

  This frame 10 is fixed to the longitudinal direction of the water tank 2 by a fixing tool 10d at an arbitrary position. Thereby, the partition plate 4 can be arrange | positioned in the arbitrary positions of the longitudinal direction of the water tank 2. FIG. The partition plate 4 may be fixed to the frame 10 at an arbitrary position in the longitudinal direction of the water tank 2.

  The control unit 6 includes an input unit and a calculation function, and the moving mechanism 5, the wave height sensor 7, and the water level meter 14 are connected by wire or wirelessly. Waveform data of the wave to be generated is input to the control unit 6 in time series. Based on the waveform data input in advance, the wave height data sequentially input from the wave height sensor 7 and the water level data sequentially input from the water level gauge 14, the control unit 6 generates a wave of waveform data determined in advance. Therefore, the vertical movement amount of the partition plate 4 necessary for this is calculated. Then, a command to move the partition plate 4 up and down by a movement amount calculated by calculation is issued to the moving mechanism 5.

  As the control unit 6, a personal computer or the like having both input means and calculation functions can be used. The input means and the calculation function can be shared by different devices.

  The wave height sensor 7 detects the wave height of the wave T between the partition plate 4 and the measurement object 8. As the wave height sensor 7, an ultrasonic wave height meter, a capacitive wave height meter, or the like can be used. The wave height sensor 7 is attached via, for example, a beam spanned in the width direction at the upper end of the water tank 2 to detect the wave height of the wave T at the center in the width direction.

  Although the number of installed wave height sensors 7 may be singular or plural, it is desirable to provide a plurality of wave height sensors 7 at intervals in the longitudinal direction of the water tank 2 in order to grasp the state of the wave T more accurately.

  The measurement object 8 is an object for which the influence of the wave T is to be measured and grasped. Examples of the measurement object 8 include a factory tank and a building model when reproducing a tsunami flooding on land. When reproducing a tsunami at sea, a model of a seawall structure such as a breakwater can be exemplified. If the measurement object 8 extending in the width direction full length or the width direction full length of the water tank 2 is used, it is possible to acquire data in a wider range in accordance with the actual situation. If the situation close to the actual site is reproduced by embedding the upper bottom surface 2a or the like, data more suitable for the actual situation can be obtained. In addition, since the data in the edge part of the width direction of the water tank 2 contain many various effects, such as reflection and interference, it analyzes using the data of the width direction center part.

  The circulation means 9 of this embodiment is composed of a water conduit 9b that connects the water reservoir 2e and the water reservoir 3 and a pump 9a that is connected to the water conduit 9b. By this circulation means 9, the water W collected in the water reservoir 2 e is absorbed from the water inlet 9 c, and the water W is supplied to the water reservoir 3 from the outlet 9 d provided at the upper part of the water reservoir 3.

  Since it is necessary to always secure the amount of water to be discharged to form the wave T in the water storage section 3, it is desirable to use a pump 9a having as large a water supply capacity as possible. Alternatively, a plurality of pumps 9a may be installed. Further, for example, the pump 9a may be connected to the control device 6 by wire or wirelessly, and the water supply amount per unit time of the pump 9a may be changed in accordance with a command from the control device 6. In this embodiment, a configuration in which the water level in the water storage unit 3 is always kept constant by using the pump 9a having a large water supply capacity, and the water level overflows from the upper end of the side plate 3a so that the water level of the water storage unit 3 is kept constant. It has become.

  The rectifier 12 is a member that adjusts the water flow in the water reservoir 3 to be constant. For example, a plate having a large number of through holes can be used as the rectifier 12. As the rectifier 12, a rectifier such as a tubular type or a ben type can be used. The rectifying body 12 is preferably arranged at a position closer to the partition plate 4 than the discharge port 9d in order to adjust the disturbance of the water flow in the water storage section 3 due to the influence of the water W supplied by the pump 9a.

  The wave-dissipating body 13 is disposed on the downstream side in the outflow direction of the water W that has flowed out of the water storage unit 3 relative to the measurement object 8. When the wave T collides with the wave-dissipating body 13, the force of the wave T is dispersed and the wave T can be prevented from being reflected. The wave-absorbing body 13 may be configured to prevent the wave T from being reflected in this way. In this embodiment, a solid three-dimensional network structure made of resin is used as the wave-dissipating body 13, and the wave energy is absorbed by the roughness (roughness) of the voids and the arrangement density. The wave-dissipating body 13 is preferably extended to the lower end of the water reservoir 2e (the recessed portion 2f).

  The water level meter 14 measures the water level downstream of the rectifier 12 of the water storage unit 3. In this embodiment, the water level gauge 14 for measuring the distance to the water surface is attached to the beam spanned in the width direction at the upper end of the water tank 2, but a water level gauge 14 of the type installed inside the water storage unit 3 may also be used. it can. As the water level gauge 14, the same thing as the wave height sensor 7 can also be used.

  When the amount of water W supplied to the water storage unit 3 is smaller than the amount of water W flowing out from the water storage unit 3, the water level of the water storage unit 3 changes. Even when the water W overflows from the side plate 3a, the water level downstream of the rectifying body 12 of the water storage section 3 may be lower than the upper end of the side plate 3a due to the influence of the rectifying body 12. The water level meter 14 is not essential, but in these cases, the water level meter 14 can accurately grasp the substantial water level of the water storage unit 3.

  The wave making device 1 of the present invention can reproduce a tsunami flooded on land and a tsunami on the sea. In this embodiment, the steps of the wave making method for reproducing a tsunami flooded on land are as follows. explain.

  When reproducing a tsunami flooded on land, the measurement object 8 is placed at a predetermined position on the upper bottom surface 2a. If necessary, the situation at the site is reproduced by embankment. The controller 6 is input with waveform data of a wave to be reproduced. The partition plate 4 is fixed at a predetermined position of the water tank 2 by the frame 10. A sufficient amount of water W is stored in the water storage portion 3 in a state where the lower end of the partition plate 4 is in contact with the upper bottom surface 2a so that the water W overflows from the side plate 3a.

  After completing the above preparation, an instruction to start the experiment is input to the control unit 6. When an instruction to start an experiment is input to the control unit 6, an instruction to move the partition plate 4 upward to an opening height H <b> 1 suitable for generating a predetermined wave is input from the control unit 6 to the moving mechanism 5. . Thereby, the partition plate 4 is moved upward along the water pressure-resistant frame 10a via the rail 11 with a bearing by the moving mechanism 5. The water W in the water reservoir 3 flows out from the opening formed by the upward movement of the partition plate 4. The water W that has flowed out of the water reservoir 3 flows on the upper bottom surface 2a toward the measurement object 8 to form a wave T.

  The wave height of the wave T is sequentially detected by the wave height sensor 7, and the detected wave height data is input to the sequential control unit 6. The control unit 6 calculates a suitable opening height H1 based on the detection data input from the wave height sensor 7, the detection data input from the water level gauge 14, and the predetermined waveform data, and the calculated opening height. The amount of water to be discharged is controlled by sequentially controlling the vertical movement of the partition plate 4 so as to be H1.

ここでＱは流出させる水の流量、Ｃｃは収縮係数、ａは仕切り板４の開口高さＨ１、Ｂは流出幅（仕切り板４の幅）、ｈ_０は貯水部３の水深、ｇは重力加速度である。 The opening height H1 of the partition plate 4 when the water W in the water storage section 3 flows out toward the measurement object 8 in the state where there is no water on the upper bottom surface 2a is, for example, the free outflow from the sluice gate. It is determined based on the following flow rate equation (1) modeled.

Where Q is the flow rate of the water to flow out, Cc shrinkage coefficient, a is the aperture of the partition plate 4 height H1, B outflow width (the width of the partition plate 4), h ₀ is the water depth of the water reservoir 3, g is the gravitational It is acceleration.

  By repeating the detection of the wave height by the wave height sensor 7 and the detection of the water level by the water level gauge 14 and the vertical movement control of the partition plate 4 by the control unit 6, the wave T having a waveform approximated to the waveform data determined in advance is reproduced. It becomes possible to do. Therefore, it is possible to generate waves having various wavelengths, periods, and wave heights. Further, as will be described later, it is possible to generate a long period wave. The wave T travels on the upper bottom surface 2a and eventually collides with the measurement object 8 disposed on the downstream side on the upper bottom surface 2a. Depending on the purpose of the experiment, data on the situation in which the wave T and the measuring object 8 collide are recorded and analyzed.

  The wave T that collides with the measurement object 8 and exceeds the measurement object 8 is quenched by the wave-dissipating body 13, and then flows into the water reservoir 2e (recessed part 2f) through the communication part 2c. The water W that has flowed into the water reservoir 2e (the recess 2f) is absorbed by the pump 9a from the water inlet 9c through the water conduit 9b, and is supplied again to the water reservoir 3 from the outlet 9d. As described above, the water W in the water tank 2 is circulated by repeating the above-described steps from the outflow from the water storage unit 3 to the return to the water storage unit 3.

  A method of simultaneously reproducing the rising waveform (step wave) at the tip of the tsunami waveform and the long-period wave (long-period wave) by the wave making device 1 will be described below.

  In the conventional wave making device, as shown in FIG. 10, the partition plate 4 is moved upward to cause the water W in the water storage section 3 to flow out and generate a step wave T1. However, since only the amount of water stored in the water storage section 3 can be discharged and the vertical movement control of the partition plate 4 is not performed, a long-period wave stable for a long time cannot be reproduced.

  On the other hand, the wave making device 1 is continuously supplied with water W by the circulation means 9 to the water storage unit 3. Therefore, the water W of the water storage section 3 does not run out even after the partition plate 4 is opened and the step wave T1 is generated.

  If the waveform data of the wave to be reproduced is input to the control unit 6, the partition plate 4 is moved to the detection data of the wave height sensor 7 and the detection data input from the water level gauge 14, and the waveform data of the wave determined in advance. Based on the above, by moving the partition plate 4 up and down, the water W can be continuously discharged while changing the opening height H1. Thereby, as illustrated in FIG. 4, the long-period wave T2 can be generated. Therefore, the wave making apparatus 1 of the present invention simultaneously generates a rising waveform (step wave T1) and a long-period wave (long-period wave T2) at the tip of a tsunami waveform such as a tsunami, and the tsunami is changed to a pulling wave. The state of the half cycle up to can be reproduced.

  In this embodiment, since the water W in the water storage part 3 flows out toward the measuring object 8 in a state where the water W does not exist on the upper bottom surface 2a, a tsunami flooding on land can be reproduced. .

  Since the water tank 2 is formed in a double bottom structure, and the communication portions 2c and 2d and the water storage portion 2e are provided, the water W discharged from the water storage portion 3 is appropriately transferred to the water storage portion 2e through the communication portions 2c and 2d. Inflow. Therefore, the water W does not overflow on the upper bottom surface 2a. And since the water W stored in the water storage part 2e and the water W on the upper side bottom face 2a are divided and are not continuous by adopting a double bottom face structure, they do not interfere with each other. Moreover, the water W overflowed from the side plate 3a flows into the water storage part 2e through the communication part 2d. Thus, the water storage part 2e functions as a buffer, and the quantity of the water W which exists on the upper side bottom face 2a is optimized without excess and deficiency. Therefore, the water W can be circulated stably and continuously.

  Since the side plate 3a having a structure in which water overflows when the water level exceeds a certain level is provided in the water storage unit 3, the water level of the water storage unit 3 can be kept constant with a simple structure. If the water level of the water storage section 3 is kept constant, the water pressure of the water W to be discharged becomes constant, so that a stable wave T can be generated.

  Since the partition plate 4 is configured to be fixed to an arbitrary position in the longitudinal direction of the water tank 2 by the frame 10, the wave-making distance can be freely set. Further, the partition plate 4 is structured to receive the water pressure received from the water W in the water storage section 3 by the water pressure resistant frame 10a, and further, the rail 11 with bearings is interposed, so that the partition plate 4 can be moved up and down smoothly. Can be done accurately. In order to generate a long-period wave, it is necessary to move the partition plate 4 up and down in a minute and quick manner, so this rail 11 with a bearing is very useful.

  Further, since the water W circulated in the water storage unit 3 is supplied to the partition plate 4 through the rectifier 12, waves and unnecessary disturbances caused by the flow of the water W circulated in the water storage unit 3 are supplied. To the water W in the water storage section 3 that flows out from the water storage section 3 toward the measurement object 8 is advantageous. This is advantageous in reproducing the wave T having a waveform approximated to the waveform data determined in advance with higher accuracy.

  Since the wave T that is rushed to the downstream side of the measuring object 8 is configured to be wave-dissipated using the wave-dissipating body 13, the wave T that exceeds the measuring object 8 is prevented from being reflected and returned. It has become advantageous. Therefore, a more accurate measurement result can be obtained without being affected by unnecessary reflected waves. In this embodiment, the wave T that is rushed to the downstream side is further dropped toward the lower bottom surface 2b to quench the wave, which is increasingly advantageous for eliminating the influence of unnecessary reflected waves.

  In addition, since the detection data by the water level gauge 14 is also taken into account when controlling the vertical movement of the partition plate 4, even when the water level of the water storage unit 3 changes, the waveform approximates the predetermined waveform data. Can be generated with high accuracy.

  The wave generator 1 illustrated in FIGS. 5 to 6 includes a weir 15 on the upper bottom surface 2a of the wave generator 1 illustrated in FIGS. Other configurations are substantially the same as those of the wave making device 1 of FIGS.

  The weir 15 is disposed at a predetermined position between the partition plate 4 and the communication portion 2 c, extends upward from the upper bottom surface 2 a, and extends the entire length in the width direction of the water tank 2. The sea is reproduced by spreading water W in a range partitioned by the partition plate 14 and the weir 15. In this embodiment, the plate-like weir 15 is installed in the communication part 2c side edge part of the upper side bottom face 2a.

  The process of the wave-making method in the case of reproducing the tsunami on the sea using this wave-making apparatus 1 is demonstrated below. The preparation stage until the experiment start command is input to the control unit 6 and the flow rate formula for determining the opening height H2 of the partition plate 4 are different from the case of reproducing a tsunami flooding on land, but otherwise the same. is there.

  In the preparation stage, first, the measuring object 8 is arranged at a predetermined position on the upper bottom surface 2a. If necessary, reproduce the conditions of the seabed at the site using sand. The controller 6 is input with waveform data of a wave to be reproduced. The partition plate 4 is fixed at a predetermined position of the water tank 2 by the frame 10. A sufficient amount of water W is stored in the water reservoir 3 in a state where the lower end of the partition plate 4 is in contact with the upper bottom surface 2a.

  In a state where the lower end of the partition plate 4 is in contact with the upper bottom surface 2a, the water W is stretched to the water depth D corresponding to the depth of the sea to be reproduced in the range partitioned by the weir 15 and the partition plate 4. Then, after the water surface is in a stable state, an experiment start command is input to the control unit 6 to start the experiment. After that, it is the same as that of embodiment shown in FIGS.

ここでＱは流出させる水の流量、Ｃｃは収縮係数、ａは仕切り板４の開口高さＨ２、Ｂは流出幅（仕切り板４の幅）、ｈ_０は貯水部３の水深（上流側水深）、ｈ_１は水深Ｄ（下流水深）、ｇは重力加速度である。 The opening height H2 of the partition plate 4 when the water W in the water storage section 3 flows out toward the measurement object 8 in a state where the water W is present on the upper bottom surface 2a is, for example, the counterflow from the sluice gate Is determined based on the following flow equation (2).

Where Q is the flow rate of the water to flow out, Cc shrinkage coefficient, a is the opening height of the partition plate 4 H2, B is (width of the partition plate 4) outflow width, h ₀ is the water reservoir 3 depth (upstream side water depth ), H ₁ is a water depth D (downstream water depth), and g is a gravitational acceleration.

  In this embodiment, since the water W in the water reservoir 3 flows out toward the measurement object 8 in a state where the water W at a predetermined water level exists on the upper bottom surface 2a, as shown in FIG. A rising waveform (step wave T1) and a long-period wave (long-period wave T2) at the tip of a tsunami waveform can be generated at the same time to reproduce the half-cycle state until the tsunami on the sea changes to a pulling wave. .

  In this embodiment, the water W is stretched in a range partitioned by the weir 15 and the partition plate 4, but the measurement target 8 and the partition are measured using the measurement target 8 extending over the entire length in the width direction of the water tank 2. A configuration in which the water W is stretched in a range partitioned by the plate 14 can also be adopted. In this case, the sea can be reproduced without providing the weir 15.

  The water tank 2 is not a double bottom surface structure, but can be a normal bottom surface as shown in FIG. In this embodiment, a tank 16 for temporarily storing water W that has flowed out of the water storage unit 3 is provided at the other longitudinal end (on the measurement object 8 side) of the bottom surface of the water tank 2, and the tank 16 and the water storage unit 3 are provided. And the water W is circulated by connecting them with the water guide pipe 9b. In this case, the allowable amounts of the water storage unit 3 and the tank 16 may be set to be large.

  As shown in FIG. 8, if the bottom surface of the water tank 2 has a gentle gradient and the wave T is generated on the bottom surface, the soliton split wave can be reproduced. The soliton splitting wave is a phenomenon in which the wave height is amplified by splitting into a plurality of waves with a short period depending on conditions such as the waveform and water depth in the process of the tsunami going up.

The wave making device 1 illustrated in FIG. 9 includes a movable weir 17 on the upper bottom surface 2a of the wave making device 1 illustrated in FIGS. The measurement object 8 is disposed between the partition plate 4 and the movable weir 17.
Furthermore, wave height sensors 7 a and 7 a for measuring the water level between the measuring object 8 and the movable weir 17 are provided. Other configurations are the same as those of the wave making device 1 of FIGS.

The movable weir 17 is disposed at a predetermined position between the partition plate 4 and the communication portion 2 c and extends the entire length in the width direction of the water tank 2. In this embodiment, a plate-like movable weir 17 is installed at the end of the upper bottom surface 2a on the side of the communication part 2c. The lower end portion of the movable weir 17 and the upper bottom surface 2 are connected by a hinge portion 17b, and the upper end portion 17a of the movable weir 17 is lifted from above the water tank 2 by a lifting portion 17c via a rod, a wire or the like. The lifting part 17c has a mechanism capable of changing the lifting height of the upper end part 17a, and the lifting part 17c moves the rod and the wire up and down to change the vertical height of the upper end part 17a. In this embodiment, the lifting part 17 c is connected to the control unit 6 by wire, and the control unit 6 controls the movement of the lifting part 17 c to control the vertical height of the distal end part 17 a of the movable weir 17. It has become.

  For example, the movable weir 17 can be configured to change the vertical height of the upper end portion 17a of the movable weir 17 by rotating the hinge portion 17b with a hydraulic cylinder, an air cylinder, a hydraulic motor, an electric motor, or the like. Each of the wave height sensors 7 a and 7 a is connected to the control unit 6 by wire.

  In this wave making device 1, water W is stored in a range partitioned by the measurement object 8 and the movable weir 17 that is regarded as a breakwater, so that the situation inside the dam when the tsunami enters the breakwater is reproduced. The steps of the wave making method will be described below. The preparation stage until the experiment start command is input to the control unit 6 and the flow rate formula for determining the opening height H2 of the partition plate 4 are the same as those in the above-described embodiment.

  In the preparation stage, first, the measurement object 8 that extends the entire length in the width direction of the water tank 2 is arranged at a position upstream of the movable weir 17 on the upper bottom surface 2a. If necessary, reproduce the situation near the sea floor and breakwater at the site using sand.

  The controller 6 receives the waveform data of the wave to be reproduced and the water level data on the inside of the bank (between the measurement object 8 and the movable weir 17) to be reproduced. The partition plate 4 is fixed at a predetermined position of the water tank 2 by the frame 10. A sufficient amount of water W is stored in the water reservoir 3 in a state where the lower end of the partition plate 4 is in contact with the upper bottom surface 2a.

  In a state where the lower end of the partition plate 4 is in contact with the upper bottom surface 2a, the water W is stretched to a water depth D corresponding to the water depth at sea to be reproduced in the range partitioned by the measurement object 8 and the partition plate 4. The vertical height of the tip 17a of the movable weir 17 is set to the water level D1 in the breakwater to be reproduced, and the water W is stretched in a range partitioned by the measurement object 8 and the movable weir 17. Then, after the water surface becomes stable at the water level D1, an instruction to start the experiment is input to the control unit 6 to start the experiment.

  Subsequent steps for forming the wave T are the same as those in the above-described embodiment. In this embodiment, however, the control unit 6 further moves the wave T beyond the measurement object 8 to move with the measurement object 8. Predetermined water level data that is to be reproduced when flowing into the weir 17 is input in advance. Then, the movable weir 17 is sequentially controlled based on the detection data input from the wave height sensor 7a and the predetermined water level data input in advance. Thereby, the water level between the measuring object 8 and the movable weir 17 is maintained at a predetermined water level inputted in advance.

In this embodiment, the water level D1 of the water W existing between the measurement object 8 and the movable weir 17 is controlled by the movable weir 17, so that the situation inside the dam when the tsunami enters the breakwater is reproduced. be able to. Since it is possible to reproduce the situation of overflow and the scouring of the mound inside the breakwater when the breakwater is damaged, it is useful for verifying the cause of damage to the breakwater and studying the design of the breakwater.

DESCRIPTION OF SYMBOLS 1 Wave generator 2 Water tank 2a Upper bottom face 2b Lower bottom face 2c, 2d Communication part 2e Reservoir part 2f Recessed part 3 Reservoir part 3a Side plate 4 Partition plate 5 Moving mechanism 6 Control part 7, 7a Wave height sensor 8 Measurement object 9 Circulation Means 9a Pump 9b Water conduit 9c Water inlet 9d Discharge port 10 Frame 10a Water pressure resistant frame 10b Support frame 10c Outer frame frame 10d Fixture 11 Rail with bearing 12 Rectifier 13 Wave absorber 14 Water level gauge 15 Weir 16 Tank 17 Movable weir 17a Upper end portion 17b Hinge portion 17c Lifting portion W Water T Wave T1 Step wave T2 Long period wave

Claims (20)

A water tank in which the measurement object is disposed, a water storage part that is installed in the water tank at an interval in the longitudinal direction of the water tank with respect to the measurement object, and on the measurement object side of the water storage part A partition plate that constitutes a surface and a moving mechanism that moves the partition plate up and down, and flows out from the measurement object side of the water storage unit opened by the upward movement of the partition plate toward the measurement object. In a wave generator that generates waves by the water in the water reservoir,
Circulating means for circulating the discharged water to the water storage unit, a control unit for controlling the vertical movement of the partition plate, and a wave height sensor for detecting the wave height between the partition plate and the measurement object. And by controlling the vertical movement of the partition plate based on the detection data by the wave height sensor and the predetermined waveform data, the predetermined waveform inside the water tank by the discharged water A wave making device that generates a wave having a waveform approximated to data.   The water tank is formed in a double bottom surface structure having an upper bottom surface and a lower bottom surface, the measurement object and the water storage section are disposed on the upper bottom surface, and formed between the upper bottom surface and the lower bottom surface. And a communicating portion that passes through the upper bottom surface in the longitudinal direction and penetrates vertically, and the water that has flowed into the reservoir through the communicating portion is circulated by the circulating means. The wave-making device according to claim 1, wherein the wave-making device is circulated in the air.   The wave making device according to claim 1 or 2, wherein the water level of the water storage unit is maintained constant.   The wave making device according to claim 3, wherein the water level in the water storage unit is maintained constant by causing the water in the water storage unit to overflow to a side facing the partition plate.   The wave making device according to claim 1, further comprising a water level meter that measures a water level of the water storage unit, and controlling vertical movement of the partition plate based on detection data by the water level meter.   A frame that fixes the partition plate at an arbitrary position in the longitudinal direction of the water tank, and a rail with a bearing that extends between the frame and the partition plate and extends in the vertical direction to contact the partition plate. The wave making device according to any one of claims 1 to 5.   The wave making device according to any one of claims 1 to 6, further comprising a rectifier installed at a position closer to the partition plate than a position where the water to be circulated flows in the water storage section.   The wave making device according to any one of claims 1 to 7, further comprising a wave-dissipating body installed downstream of the measurement object in the outflow direction of the water that has flowed out.   A movable weir is provided on the downstream side in the outflow direction of the discharged water from the measurement object, and water is stored between the measurement object and the movable weir, and the water level is changed by the movable weir. The wave making device according to any one of claims 1 to 8, wherein the wave making device is configured. The measurement object and the water storage part are arranged inside the water tank with an interval in the longitudinal direction of the water tank, and the partition plate constituting the surface of the water storage part on the measurement object side is moved upward to move the water storage In the wave making method of opening the measurement object side of the part and causing the water in the water storage part to flow out toward the measurement object, and generating a wave with the discharged water,
The effluent water is circulated to the water reservoir, and the wave height is detected between the partition plate and the measurement object by a wave height sensor, and based on the detection data and predetermined waveform data. A wave-making method, wherein a wave having a waveform approximate to the predetermined waveform data is generated by the discharged water by controlling the vertical movement of the partition plate.   The water tank has a double bottom surface structure having an upper bottom surface and a lower bottom surface, the measurement object and the water storage section are disposed on the upper bottom surface, and water is stored between the upper bottom surface and the lower bottom surface. 11. The communication device according to claim 10, further comprising a communication portion that vertically penetrates at both longitudinal ends of the upper bottom surface, and circulates the water that has flowed into the water storage portion through the communication portion to the water storage portion. Wave making method.   The water in the said water storage part is made to flow out toward the said measuring object in the state in which the water of a predetermined water level exists between the said measuring object inside the said water tank and the said partition plate. Wave making method.   The wave making method according to claim 10 or 11, wherein water in the water storage section is allowed to flow toward the measurement object in a state where no water exists between the measurement object inside the water tank and the partition plate. .   The wave making method according to any one of claims 10 to 13, wherein the water in the water storage part flows out toward the measurement object while maintaining a water level of the water storage part constant.   The wave making method according to claim 14, wherein the water level in the water storage unit is kept constant by causing the water in the water storage unit to overflow to the side facing the partition plate.   The wave making method according to any one of claims 10 to 13, wherein the water level of the water storage unit is detected by a water level gauge, and the vertical movement of the partition plate is controlled based on the detection data.   The said partition plate is fixed in the arbitrary positions of the longitudinal direction of the said water tank with a flame | frame via the rail with a bearing extended in the up-down direction and contact | abutting to the said partition plate. Wave making method.   The wave making method according to any one of claims 10 to 17, wherein the water circulated through the water storage section is supplied to the partition plate side through a rectifying body provided in the water storage section.   The wave making method according to any one of claims 10 to 18, wherein the wave that is pushed toward the downstream side in the outflow direction of the water that has flowed out of the measurement object is wave-absorbed by a wave-dissipating body.   A movable weir is provided on the downstream side in the outflow direction of the water that has flowed out from the measurement object, and water is stored at a predetermined water level between the measurement object and the movable weir. Water is caused to flow out toward the measurement object, and a water level stored between the measurement object and the movable weir is detected by a wave height sensor, and based on this detection data and predetermined water level data The water stored between the measurement object and the movable weir is controlled to a predetermined water level by changing the vertical height of the movable weir. Wave method.

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