JP6300199B2 - Rotation prevention structure for movable breakwater - Google Patents

Description

  The present invention relates to a structure for preventing rotation of a movable breakwater, and more specifically, to a technique for easily and inexpensively preventing rotation of a steel pipe in a movable breakwater.

  A movable breakwater has been proposed that is near the seabed under normal weather conditions, but protrudes above the sea surface during stormy weather or when a tsunami occurs, and suppresses the incidence of waves into the back area. This movable breakwater is mainly composed of a lower steel pipe standing on the seabed and an upper steel pipe that slides up and down in the inner space. It can be a situation where it rotates in the lower steel pipe. When the upper steel pipe rotates, the coupler that supplies power to the drive mechanism or the like is displaced between the upper steel pipe and the lower steel pipe, and the adjustment work of the steel pipe position occurs. In addition, there is a concern that damage and cutting of the rope hanging the upper steel pipe with the adjacent steel pipe as a fulcrum may occur.

  Therefore, the following techniques have been proposed as techniques for preventing the steel pipe from rotating in such a movable breakwater. That is, the movable breakwater includes a protrusion extending in the longitudinal direction along the outer peripheral surface of the upper steel pipe, and the protrusion is accommodated in a stabilizer gap provided at the top of the lower steel pipe. A technique for suppressing rotation of a steel pipe (Patent Document 1) has been proposed.

JP 2008-255718 A

  However, in the movable breakwater adopting the prior art, since the separation distance between the protrusion of the upper steel pipe and the inner wall surface of the lower steel pipe is very small, when the upper steel pipe is levitated in the lower steel pipe, the protrusion and the lower There is a concern that the inner wall surface of the steel pipe is likely to come into contact with each other, and there is a problem that the upper steel pipe cannot float. On the other hand, in order to avoid such a situation as much as possible, the manufacturing accuracy of each of the upper steel pipe and the lower steel pipe, the roundness error, and the bending are improved. If measures such as frequency are taken, there is a problem that the cost, labor, and construction period for production and construction become excessive.

  Then, this invention aims at provision of the technique which implement | achieves rotation prevention of the steel pipe in a movable breakwater easily and at low cost.

The structure for preventing the rotation of the movable breakwater that solves the above problems includes a plurality of lower steel pipes that are inserted vertically through the bottom of the water into the bottom of the water and open at the top end in the water, and each bottom steel pipe When the upper steel pipe rotates around its axis, the upper steel pipe interferes with the upper end of the upper steel pipe to regulate the rotation of the upper steel pipe. A rotation preventing structure of a movable breakwater provided on the upper steel pipe , wherein the rotation restricting member is fixed to a top end portion of one upper steel pipe among the adjacent upper steel pipes, At least a pair of girders that reach the top end of the steel pipe and at the top end of the other upper steel pipe at a predetermined distance from the corresponding girders on the left and right sides of the end of the girder Projecting members, or It characterized in that it is become one.

  According to this, excessive consideration is given to the manufacturing accuracy and construction accuracy related to the dimensions, roundness error, bending, etc. of the steel pipe at the top end of the upper steel pipe that does not affect the floating operation and construction work of the movable breakwater. It will be equipped with an anti-rotation structure that is not required, ensuring a large separation between the outer surface of the upper steel pipe and the inner surface of the lower steel pipe, and the problem of the floating operation of the upper steel pipe due to the contact between members due to the construction accuracy and manufacturing accuracy described above. It is possible to avoid excessive costs, labor, and construction time for manufacturing and construction. Therefore, it is possible to easily and inexpensively prevent the steel pipe from rotating on the movable breakwater.

Further, the rotation restricting member is fixed to the top end portion of one upper steel pipe among the adjacent upper steel pipes, and the girder reaching the top end portion of the other upper steel pipe, and the top end portion of the other upper steel pipe The at least one pair of projecting members installed at a predetermined distance from the corresponding girder on both the left and right sides of the end portion of the girder, the girder of the adjacent upper steel pipes is fixed. In addition, the rotational behavior of one upper steel pipe causes runout in the plane direction of the girders on the top end of the other upper steel pipe, but the protruding members on the top end abut against the girders and interfere with each other. , It is possible to limit the runout to a certain range. In addition, when the rotation behavior of the other upper steel pipe occurs, the projecting member provided at the top end of the other upper steel pipe also attempts to rotate on the plane including the corresponding top end, but the same occurs with respect to the projecting member. The spar on the top end abuts and interferes, and its rotational behavior can be limited to a certain range. Such restriction of the swing width of the girders and the rotation range of the protruding member corresponds to the restriction of the rotational behavior of the one upper steel pipe described above.

If the rotation restricting member is made of a cord-like material that connects the top ends of the adjacent upper steel pipes, when rotation behavior occurs in any one of the upper steel pipes, A cord-like material with a predetermined location fixed to the top end of the upper steel pipe receives the tensile force according to the above-mentioned rotational behavior, but the other upper steel pipe with one end fixed resists and interferes with the fulcrum, and rotates. The range can be limited to a certain level.

  ADVANTAGE OF THE INVENTION According to this invention, rotation prevention of the steel pipe in a movable breakwater can be implement | achieved easily and at low cost.

It is explanatory drawing which shows the rotation prevention structure example 1 of the movable breakwater in this embodiment. It is a top view which shows the rotation prevention structure example 1 of the movable breakwater in this embodiment. It is a top view which shows the example of an operating condition of the rotation prevention structure example 1 in this embodiment. It is explanatory drawing which shows the example of a behavior of the lap | wrap part in the rotation prevention structure of this embodiment. It is explanatory drawing which shows the rotation prevention structure example 2 of the movable breakwater in this embodiment. It is a top view which shows the rotation prevention structure example 2 of the movable breakwater in this embodiment. It is a top view which shows the example of an operating condition of the rotation prevention structure example 2 in this embodiment.

  Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory view showing Example 1 of the rotation prevention structure 100 in the movable breakwater 10 of the present embodiment, and FIG. 2 is a plan view thereof. The rotation prevention structure 100 of the movable breakwater 1 in the present embodiment is such that when the upper steel pipe constituting the movable breakwater 1 rotates around its axis, the upper steel pipes interfere with each other between the adjacent upper steel pipes. The rotation is restricted, and the rotation prevention of the upper steel pipe 10 on the movable breakwater 1 is realized easily and at low cost.

  The movable breakwater 1 to which such an anti-rotation structure 100 is applied includes a lower steel pipe 20 that is vertically placed on the bottom of the seabed G and opens upward, and the above-described upper steel pipe 10 that moves up and down in the inner space 21 is in the sea. S is arranged in line with S and is configured to suppress the invasion of waves into the back region A thereafter.

  As the upper steel pipe 10 in the present embodiment, a main pipe 10A that rises in the sea S by buoyancy generated by supply of air to the inner space 11 by a pneumatic feeding means such as an air pump and protrudes above the sea surface F, and the main pipe 10A. The upper steel pipe adjacent to both sides of the main pipe 10A, and the side pipe 10B that floats as the main pipe 10A floats. In the example of FIG. 1, an example in which the side tube 10B is disposed on both sides of the main tube 10A is shown, but a configuration in which the side tube 10B is disposed only on one side of the main tube 10A may be employed.

  Further, between the main pipe 10A and the side pipe 10B described above, the girders 101 that are fixed to the top end 12 of the main pipe 10A and each end 103 reaches the top end 15 of the side pipe 10B are passed. Yes. This girder 101 is made of a steel material having a predetermined strength, and constitutes a rotation restricting member in the rotation preventing structure 100 of the present embodiment. In addition, although the above-mentioned end part 103 in the girder 101 reaches the top end part 15 of each side pipe 10B, it is not fixed there.

  Further, the girder 101 has a rope 104 such as a synthetic resin rope suspended downward through an opening 16 (in the enlarged view surrounded by a broken line in FIG. 1) in the top end 15 of the side tube 10B. The lower end 104A of the cable member 104 is connected to a partition wall 18 provided in the inner space 17 of the side pipe 10B. That is, the girder 101 suspends the side pipe 10 </ b> B by the cord material 104 connected to the partition wall 18. Therefore, as the beam member 101 rises from the initial position in accordance with the above-described floating operation of the main pipe 10A, the side pipe 10B suspended by the cord material 104 also rises. Note that the structure for the floating operation of the main pipe 10A and the side pipe 10B is an example, and the rotation prevention structure 100 of the present embodiment may be applied to a structure employing other means.

  The rotation restricting member in the rotation preventing structure 100 of the present embodiment includes a protruding member 105 installed on the top end portion 15 of the side tube 10B in addition to the above-described beam member 101. The projecting members 105 are installed on the left and right sides of the end portion 103 of the beam member 101 on the top end portion 15 of the side tube 10B with a predetermined distance d from the side surface 103A of the end portion 103. , 105B and 105C. The example of the protruding member 105 shown in FIGS. 1 to 3 shows a configuration in which two pairs 105C of unit protruding members 105A and 105B are installed at the top end 15 of the side tube 10B. Of course, the number of the pair 105C is not particularly limited as long as it is one or more.

  According to such an anti-rotation structure 100, as illustrated in FIG. 3, the planer direction of the beam member 101 on the top end portion 15 of each side tube 10B due to the rotation behavior of the main tube 10A to which the beam member 101 is fixed. When the wobbling occurs, the projecting member 105 on the top end portion 15 abuts against and interferes with the beam member 101, and the wobbling width can be limited to a certain range. Further, when the rotation behavior of the side tube 10B occurs, the projection member 105 provided in the top end portion 15 of the side tube 10B also tries to rotate on the plane including the top end portion 15; On the other hand, the beam member 101 on the same top end portion 15 abuts and interferes, and the rotational behavior can be limited to a certain range.

  In addition, when the main pipe 10A receives an excessive wave such as a tsunami, the main pipe 10A has a behavior that tends to largely tilt toward the back region A starting from a lap portion 50 (see FIG. 4) with the lower steel pipe 20. Accordingly, the girders 101 also try to move horizontally on the top end 15 of the side tube 10B with a large amplitude. At this time, when the above-described separation distance d is extremely small, for example, when the unit projecting members 105A and 105B and the side surface 103A of the end portion 103 of the beam member 101 are in contact with each other from the beginning, The load received by the main pipe 10A from the above-described waves is applied to the protruding member 105 on the top end portion 15 of the side pipe 10B through the girder 101 as it is. This is the same even when the side tube 10B receives excessive waves.

  Therefore, the displacement of the above-described inclination or the like generated in the upper steel pipe 10 to resist the above-described load as a whole of the upper steel pipe 10 and the lower steel pipe 20 without receiving the load due to excessive waves such as tsunami only by the protruding member 105. Is considered as a relative displacement between the main pipe 10A and the side pipe 10B adjacent to each other where the girder 101 is installed, and it is preferable to determine a separation distance d that allows this.

  For example, as shown in FIG. 4, it is assumed that the lap portion 50 of the upper steel pipe 10 and the lower steel pipe 20 has a play Xmm (when the upper and lower lap portions are equal) and the wrap portion 50 has a length Ymm. The inclination of the upper steel pipe 10 when receiving waves in this state can be calculated as (X × 2) / Y = Z. Moreover, if the upper steel pipe length excluding the wrap portion 50 is Vmm, the displacement at the upper end of the upper steel pipe is V × Z = Wmm.

  Therefore, the displacement W at the top end of the upper steel pipe 20 is added with an error related to verticality when the lower steel pipe 20 is placed, a bending error when manufacturing the steel pipe, a deformation amount due to roundness error, etc. What is necessary is just to calculate the relative displacement between 10A and the side pipe | tube 10B, and to determine the separation distance d so that it may become this calculated value or more.

  If the protruding member 105 is installed according to the separation distance d determined in this way, when the main pipe 10A that has received an excessive wave such as a tsunami is inclined, a top end portion of the side pipe 10B accompanying this occurs. The amount of movement of the girders 101 on 15 is equal to or less than the above-mentioned separation distance d, and a situation in which the load received by the main pipe 10A from the waves is directly applied to the protruding member 105 can be avoided.

  Then, the other example of the rotation prevention structure 100 in the movable breakwater 10 of this embodiment is demonstrated. FIG. 5 is an explanatory view showing Example 2 of the rotation prevention structure 100 of the movable breakwater 10 of the present embodiment, and FIG. 6 is a plan view thereof. In this example as well, the configuration of the movable breakwater 10 is assumed to be the same as in Example 1 described above.

  The rotation prevention structure 100 in this case is composed of a cord-like material 40 that connects between the top end 12 in the main pipe 10A and the top end 15 in each side pipe 10B. The cord-like body 40 can employ a synthetic resin rope, a steel chain, or the like. According to such a cord-like body 40, as illustrated in FIG. 7, for example, when a rotating behavior occurs in the main pipe 10A among the adjacent main pipe 10A and the side pipe 10B, the top end portion of the main pipe 10A is formed. The cord-like material 40 having one end 41 fixed to 12 receives a pulling force according to the above-described rotational behavior, but resists and interferes with the side tube 10B having the other end 42 fixed to the fulcrum, and the main tube 10A rotates. The range will be limited to a certain level. Of course, the rotation range can be similarly limited when the side pipe 10B has a rotational behavior.

  In the meantime, when the main pipe 10A receives an excessive wave such as a tsunami, the main pipe 10A starts from the lap portion with the lower steel pipe 20 as in the case of the distance d related to the protruding member 105. The behavior which tends to largely incline toward the back region A occurs, and accordingly, the cord-like body 40 also receives a large pulling force. At this time, the play of the length in the cord 40 is extremely small. For example, when the cord 40 is handed over at the shortest distance between the fixed portions in the main pipe 10A and the side pipe 10B, the above-mentioned waves are used for the main wave. The load received by the pipe 10A is applied almost directly to the fixing portion of the cord 40 on the top end 15 of the side pipe 10B via the cord 40. This is the same even when the side tube 10B receives excessive waves.

  Therefore, the upper steel pipe 10 and the lower steel pipe 20 as a whole are resistant to the above-described loads without receiving a load caused by an excessive wave such as a tsunami directly at the fixing portion of the cable-like body 40 and the rope-like body 40. It is preferable to consider the displacement such as the inclination described above as the relative displacement between the main pipe 10A and the side pipe 10B adjacent to each other where the cord-like body 40 is installed, and to determine the play that allows this. The concept of the relative displacement calculation method is the same as in the case of the separation distance d described above, and the play of the cord-like body 40 may be determined so as to be equal to or greater than the calculated value of the relative displacement.

  If the cable-like body 40 having a length including the play determined in this way is installed, when the main pipe 10A that has received an excessive wave such as a tsunami is inclined, the rope-like body 40 is pulled accordingly. The length of the cable is equal to or less than the above-described play, and it is possible to avoid a situation in which the load received by the main pipe 10A from the waves is directly applied to the cable-shaped body 40 or the fixing portion of the cable-shaped body 40.

  According to this embodiment, rotation prevention of the steel pipe in a movable breakwater can be realized easily and at low cost.

  As mentioned above, although embodiment of this invention was described concretely based on the embodiment, it is not limited to this and can be variously changed in the range which does not deviate from the summary.

G Submarine ground S Underwater A Rear area F Sea surface d Separation distance 1 Movable breakwater 10 Upper steel pipe 10A Main pipe 10B Side pipe 11 Upper steel pipe interior 12 Main pipe top end 15 Side pipe top end 16 Side pipe top end Opening portion 17 Side pipe inner space 18 side pipe partition wall 20 Lower steel pipe 21 Lower steel pipe inner space 40 Cable-like body 41 One end of the rope-like body 42 Other end of the rope-like body 100 Anti-rotation structure 101 Girder 103 Girder end 103A Girder Side surface 104 of end portion 104 cord member 104 lower cord member 105 projection member 105A, 105B unit projection member 105C pair of unit projection member

Claims (2)

Movable with a plurality of lower steel pipes that penetrate the bottom of the water and are vertically inserted into the water bottom ground and arranged with the upper end surface open in the water, and upper steel pipes that are inserted in each lower steel pipe so as to be movable up and down In the type breakwater, when the upper steel pipe rotates about its axis, the movable steel breakwater is provided with a rotation restricting member for restricting the rotation of the upper steel pipe by interfering at the top end portion between the adjacent upper steel pipes. Anti-rotation structure of
The rotation restricting member is
A girder fixed to the top end of one upper steel pipe among the adjacent upper steel pipes and reaching the top end of the other upper steel pipe,
At the top end of the other upper steel pipe, at least a pair of projecting members installed at a predetermined distance from the corresponding girder on the left and right sides of the end of the girder,
A structure for preventing rotation of a movable breakwater characterized by comprising: Movable with a plurality of lower steel pipes that penetrate the bottom of the water and are vertically inserted into the water bottom ground and arranged with the upper end surface open in the water, and upper steel pipes that are inserted in each lower steel pipe so as to be movable up and down In the type breakwater, when the upper steel pipe rotates about its axis, the movable steel breakwater is provided with a rotation restricting member for restricting the rotation of the upper steel pipe by interfering at the top end portion between the adjacent upper steel pipes. Anti-rotation structure of
The structure for preventing rotation of a movable breakwater, wherein the rotation restricting member is made of a cord-like material connecting the top ends of the adjacent upper steel pipes .

Images