Abstract
In order to achieve a swing motion type retractable floodgate using a cost-effective torsion structure, the present invention is provided with a swing pivot support mechanism, a friction shoe, a door bottom support seat, and an operation step during a tidal flow. The support mechanism allows free rotation about three axes and restricts motion in the three axis directions, and a pulling force acts on the support mechanism. The friction shoe dissipates tidal energy during closing operations in a tidal flow to a level that prevents damage to the door. Reactive forces are endured by reducing impact forces with the flexibility and strength of the door bottom support seat. Suitable tidal energy dissipation is performed by selecting friction force strength in the operation step.
Claims
1. A sluice gate comprising a door mounted vertical to water flow or vertical to the course of boats and ships, said door being moored in a storage position when said gate is completely opened, and said door moving to a completely closed position in a floating state when said gate is completely closed by swing motion about an axis, said axis extending vertically to a horizontal water surface, characterized in that said door has a support point fixed to the water bottom beneath a lowermost surface of the sluice gate, and the door is freely rotatable about three axes at the support point and is restricted from translational motion in three axis directions at the support point.
2. The sluice gate according to claim 1, characterized in that during the operation of said sluice gate, a pulling force is applied on said support point.
3. The sluice gate according to claim 1, characterized in that the bottom of said door comprises a friction shoe, wherein the tread tip of said friction shoe has a convex curvature form.
4. The sluice gate according to claim 1, characterized in comprising a bottom support seat provided at a location where said door contacts a structure on the port side sea bottom, wherein said bottom support seat is structured to be flexible and highly strong by embedding a steel material inside a soft material.
5. The sluice gate according to claim 1, wherein the support conditions of said support point are freely rotatable about three perpendicular axes and restricting motion in three perpendicular axis directions.
6. The sluice gate according to claim 1, wherein the sluice gate comprises a spherical seat provided in the lowermost surface of the sluice gate, and wherein a spherical head fixed to the water bottom is positioned within the spherical seat.
7. A sluice gate comprising a door mounted vertical to water flow or vertical to the course of boats and ships, said door being moored in a storage position when said gate is completely opened, and said door moving to a completely closed position in a floating state when said gate is completely closed by swing motion about an axis, said axis extending vertically to a horizontal water surface, characterized in that said door has support points fixed to the water bottom beneath a lowermost surface of the sluice gate and to an upper portion of said door, and said support points have a common central axis, and the door is freely rotatable about two axes at a lower support point of the support points and is restricted from translational motion in three axis directions at the lower support point.
8. The sluice gate according to claim 7, wherein the support conditions of said support point are freely rotatable about two perpendicular axes and restricting motion in three perpendicular axis directions.
Description
BRIEF DESCRIPTION OF DRAWINGS
(1) FIG. 1 illustrates an example of a torsion structure flap gate supported by a water bottom concrete structure.
(2) FIG. 2 is an explanatory drawing of a swing movement type.
(3) FIG. 3 is an example of tidal sluice gate planning data.
(4) FIG. 4 is an overall view of Embodiment 1 and is an embodiment of a swing movement type hydraulic gate door.
(5) FIG. 5 illustrates a float tank arrangement and gate leaf acting forces of FIG. 4.
(6) FIG. 6 is a detail drawing of operation tank of FIG. 5 and illustrates partition of a buoyancy and a backup buoyancy
(7) FIG. 7 is calculated results of FIG. 5 and FIG. 6.
(8) FIG. 8 an explanatory drawing of a swing center mechanism in Embodiment 1.
(9) FIG. 9 is a detail drawing of a friction shoe in Embodiment 1.
(10) FIG. 10 an explanatory drawing of the friction shoe and is an external force acting drawing before inclination.
(11) FIG. 11 an explanatory drawing of the friction shoe and is an external force acting drawing after inclination.
(12) FIG. 12 is an example of friction shoe bottom fashions.
(13) FIG. 13 is external moment (torsion moment) working on gate leaf unit width.
(14) FIG. 14 is a control limit of a side thruster.
(15) FIG. 15 is a plan of installation site where a gate leaf of Embodiment 1 is operated with the help of tidal flow.
(16) FIG. 16 illustrates steps of the operation in tidal flow of Embodiment 1.
(17) FIG. 17 is an explanatory drawing of a swing center support mechanism of Embodiment 2.
(18) FIG. 18 is an explanatory drawing of a bottom support seat of Embodiment 3.
EMBODIMENTS OF THE INVENTION
(19) FIG. 3 is an example of tidal sluice gate planning data.
Embodiment 1
(20) FIG. 4 is an example based upon the data of FIG. 3 and illustrates a swing movement type tidal sluice gate. FIG. 4 illustrates the left half of the tidal sluice gate viewed from a sea side. FIG. 4A is a plan. FIG. 4B is an elevation.
(21) 6 denotes a gate leaf in a completely closed state. 7 denotes a gate leaf in a completely opened state. The sluice gate of FIG. 2 is in either state 6 or 7.
(22) 8 denotes a swing center of the gate leaf 6, 9 denotes a storage pier of the gate leaf 7, 10 denotes a center line of the tidal sluice gate. 11 denotes a swing center support mechanism, 12 denotes side thrusters, and 13 denotes a friction shoe.
(23) The gate leaf 7 in the completely opened state is tied up at the storage pier 9. When in use, the gate leaf (in its open state) 7 moves by swing motion around the swing center 8 to the position of the gate leaf (in its closed state) 6 and mounts on a water bottom after exhausted its buoyancy.
(24) FIG. 5 is the gate leaf 7 in swinging motion of FIG. 4 and illustrates float tank arrangement and acting forces of the gate leaf 7. FIG. 6 is a detail drawing of the operation tank on FIG. 5 and illustrates partition of a buoyancy and a backup buoyancy.
(25) The tank arrangement of FIG. 5 includes three kind of tanks which ara an operation tank, a balance tank and a upright tank and the acting force of FIG. 5 includes 5 kind of forces which are operation buoyancy, balance buoyancy, upright buoyancy, gate leaf weight W and pulling-up force S and the gate leaf 7 of FIG. 4 floats on water by the operation tank backup buoyancy of FIG. 6. Role of each tank is as following.
(26) Upright tank: Maintenance of gate leaf uprightness by coupled with the pulling-up force S
(27) Balance tank: Downsizing the operation tank by balanced with majority of the gate leaf weight
(28) Operation tank: Downwelling/surfacing operation of the gate leaf by filling/draining water in it
(29) FIG. 7 is a calculation result of the acting forces and the tank capacity which are shown on FIGS. 5 and 6. The calculation result is an estimate including assumptions that steel displacement is negligible, the buoyancy works upon each float tank center, flee surface effect of the tanks is negligible, and specific weight of water equals 1. Center height of the balance tank and the upright tank approximately coincide with the gate leaf gravity height. As the both tanks always submerge, their backup buoyancy is zero and the gate leaf in swing motion floats on water surface only with the backup buoyancy of the operation tank accordingly. Water of the same quantity as the backup buoyancy (1126 tf) is poured into the operation tank after gate leaf 7 of FIG. 4 arrives at the position of the gate leaf 6 in completely closed state, then the tank buoyancy in FIG. 7—the pulling-up force S=9000 tf which consorts with the gate leaf weight W. If the gate leaf 7 is softly pushed down in this instant of time a free end of the gate leaf 7 starts to sink, the friction shoe 13 on FIG. 4 arrives at a water bottom (the bottom mounting), and the gate leaf 7 is fit in the position of the gate leaf 6 on FIG. 4. A load of the friction shoe 13 in this state is zero. The load of friction shoe 13 becomes 1074 tf when additional water quantity poured into the operation tank arrives at the tank buoyancy (1074 tf). As overturn moment of the gate leaf 6 at this time is linear to the shoe load and upright moment is linear to the pulling-up moment S, a safety factor becomes about 2.7 and overturn of the gate leaf 6 will be avoided (corresponding to previously mentioned “Problem 1: Gate leaf stability at gate mounting on a water bottom”).
(30) The swing center support mechanism 11 of FIG. 4 is a support point fixed on a water bottom, whose support condition is rotation free and moving constraint in three axes directions A1, A2, and A3 and always subject to pulling-up force. FIG. 8 illustrates an example which satisfies this support condition. FIG. 8A is an elevation of the swing center mechanism 11. FIG. 8B is AA section of FIG. 8A. FIG. 8C is BB section of FIG. 8B. FIG. 8D is CC section of FIG. 8C. FIG. 8E is DD section of FIG. 8D. FIG. 8F is EE section (metals) of FIG. 8E. The gate end support key of FIG. 8A is the functional heart of the swing center support mechanism 11 and FIG. 8B thru FIG. 8F show details of the gate end support key. A section of the key of FIG. 8C is an across shape which is shown on FIG. 8E and the upper half of it composes a key spherical head which is shown on FIG. 8C. A key support is fixed to a anchorage embedded in a sea bottom concrete that is shown on FIG. 8F, the lower half of the key is inserted into the key support that is shown on FIG. 8C, and they are joined together with wire clips. The key spherical head fixed to a sea bottom as described above is covered by a spherical seat fitted on the gate leaf side as shown on FIG. 8C. The inside of the spherical seat and the outside of the key spherical head work as bearing surfaces and they facilitate load carrying function and sliding function. The lower half of the spherical seat is fixed by welding to the gate leaf side and the upper half of it is removable fitting of bolts out of a maintenance need. The lower half of the spherical seat is usually subject to the pulling-up force S which works upward.
(31) Support condition of the swing center support mechanism 11 on FIG. 4 is rotation free and moving constraint in three axes directions. On the other hand, pendulum of the gate leaf during its swing motion in ocean waves is rolling, pitching, dipping etc. The pendulum motion of the gate leaf has a rotation element and a removing element at a support point of the swing center support mechanism 11. Although the removing element is restricted by the support point of the three axes direction moving constraint, the rotation element is not restricted by the support point of the three axes direction rotation free and impact of the gate leaf pendulum on its structural strength will be remarkably mitigated (corresponding to previously mentioned “Problem 2: Gate leaf motion at gate open and closure operation”).
(32) FIG. 9 is a detail of the friction shoe 13 on FIG. 4. FIG. 9A is an enlarged view of the gate leaf (solid line, in a closed state) 6. FIG. 9B is AA section of FIG. 9A. FIG. 9C is BB section of FIG. 9B.
(33) Reference numeral 6 denotes a gate leaf, 8 denotes a swing center. 13 denotes a friction shoe, 14 denotes an upper of the friction shoe 13, 15 denotes a wear-resistant material covering a tread of the friction shoe 13, 16 denotes a bottom support seat (water sealing) or the gate leaf 6, 17 denotes a tip of the wear-resistant material 15, and 18 denotes an are radius of the tip 17.
(34) The tip 17 of the wear-resistant material 15 covering a tread of the friction shoe 13 which is shown on FIG. 9B composes an are of the radius 18.
(35) FIGS. 10 and 11 illustrate a gate leaf on which a couple consisting of the tide difference Δ h and the shoe friction force is working and FIG. 10 is the gate leaf before inclination emerges and FIG. 11 is after inclination emerges. The shoe reaction force and the shoe friction force (=Shoe reaction force×Friction coefficient) of FIG. 10 work on the point right below the shoe load working at the gravity center and these of FIG. 11 have removed to the position of the radius 18. A horizontal component and a vertical component of the tide difference Δ h work on the gate leaf due to the inclination of β°. Consequently, the vertical component of the tide difference Δ h is added to the shoe reaction force and the shoe friction force. The gate leaf stays at the inclination angle of β° in the state that the inclination moment composed of a coupling which consists of the horizontal component of the tide difference Δ h and the shoe friction force and a coupling which consists of the vertical component of the tide difference Δ h and the shoe reaction force consorts with the upright moment composed of a coupling which consists of the shoe load and the shoe reaction force and a coupling which consists of the pulling-up force S and the upright buoyancy. In addition, the inclination would not emerge when the friction coefficient is small (for instance, the friction coefficient <0.3) because a coupling of the shoe load and the shoe reaction force is predominantly grater than a coupling of the shoe friction force and the horizontal component of the tide difference Δ h and the gate leaf removes up, to the completely closed position keeping upright state (corresponding to previously mentioned “Problem (3.1): Gate leaf lateral inclination”).
(36) There can be many shoe tread forms with which the gate leaf can remove keeping upright state or small inclination angle β°. FIG. 12 illustrates the examples. The form combination items of the examples are both ends or one end of a bend side, vertical or inclined of a end wall form and a circular arc or a free curve of a bent form, and a common appearance of all the combinations is the tip 17 of convex curvature form.
(37) Tidal flows in the world excluding special geographies as seen at Seto Inland Sea etc. are between 1.0 and 3.0 Kt (≈0.5 and 1.5 m/s) in general. The gate leaf closing operation in tidal flow, in short, the operation in tidal flow is made at flow speed of this level.
(38) FIG. 13 illustrates external moments (torsion moments) working on unit width of the gate leaf during a high tide and at a collision during the operation in tidal flow. They are results of calculation based on the data of FIG. 3. The external load at a collision is inertia force of the gate leaf and its virtual mass and the magnitude of inertia force has been so determined that strain energy resulted in the gate leaf may equal strain energy accumulated in the gate leaf during a high tide. Suppose the strain energy during a high tide corresponds to yield stress, the corresponding external moment during a collision will be the structural limit of the gate leaf and it is calculated on the moment that the gate leaf tip speed is between 1 and 1.5 m/s and the impact force on the gate leaf bottom support seat is 321 tf/m. The width of calculated speed is due to difference of the virtual mass considered.
(39) It is estimated that there may be a case where a reduction of tidal flow energy becomes necessary to avoid the gate damage during the operation in tidal flow. Its means are the friction force of friction shoe, a side thruster, a tug-boat etc. The friction force will be 107 ft in the case that the shoe load is 1074 tf and the friction coefficient is 0.1. FIG. 14 is an example of control limit of gate leaf mounting type side thrusters and shows control limits of keeping the gate leaf in rest state by flow velocity and tide difference.
(40) FIG. 15 is a plan of a gate leaf installation site and illustrates a bottom mounting position, a totally closed position, a bottom mounting angle θc a direction of tidal flow, and, a swing center for the operation in tidal flow.
(41) FIG. 16 is a gate leaf closing step of the operation in tidal flow. As the friction force of Step 2=the friction load×the friction coefficient and the shoe load=1074−the operation buoyancy, the intensity of friction force is selected by a proper selection of the operation buoyancy. The operation buoyancy selection is made according to a selection chart. The selection chart will be prepared according to results of a hydraulic model experiment and a prototype verification test carried out at every project. The tidal flow level, the gate leaf collision velocity and the energy dissipation level are shown at [0041] thru [0043] where kinetic energy of the gate leaf which arrives at the totally closed position is maintained at lower than the limit value by following the closing operation steps of FIG. 16 and gate leaf damage and destructive impact force eruption are avoided due to the kinetic energy transfer to the strain energy there (corresponding to previously mentioned “Problem (3.2): Impact energy”).
(42) The step 3 of FIG. 16 indicates a gate leaf move by tidal flow force. Although the tidal flow force is being dissipated by the friction force and conveys the gate leaf up to the completely closed position where the gate leaf keeps its velocity less than or equal to the limited value, a gate leaf tip speed sensing during the operation and, if necessary, a limit speed keeping by side thrusters etc. are required since the friction force=the shoe load×the friction coefficient and the friction coefficient may vary across the ages. And after the gate levitation prevent apparatus is set on at the step 8, appropriate buoyancy is given to the gate leaf by air filling into the operation tank in order to provide for a open operation by tidal flow in reverse direction due to tide level lowering.
Embodiment 2
(43) FIG. 17 is another example of the swing center support mechanism which is shown on FIG. 8 and while FIG. 8 shows an example which satisfies the support condition of rotation free and moving constraint in three axes directions, FIG. 17 shows an example which satisfies the support condition of rotation free in two axes directions A1 and A3 (sec FIG. 17A) and moving constraint in three axes directions A1, A2, and A3.
(44) FIG. 17A is an elevation of the swing center support mechanism 11. FIG. 17B is FF section of FIG. 17A. FIG. 17C is GG section of FIG. 17B. FIG. 17D is HH section of FIG. 17C. The end rotation axle of FIG. 17A is a mechanism which is added to FIG. 8A and FIG. 17B thru 17D shows details of the end rotation axle. For a detail of the end support key of FIG. 17A, the details of end support key shown on FIG. 8B thru 8E are applicable. As shown on FIG. 17B, the round axle is fixed on the hydraulic gate support pier, the long axle hole is fixed on the gate leaf side and the round axle is set by being inserted into the long axle hole. FIG. 17C shows the long axle hole fixed on the gate leaf side and the round axle set by being inserted into the long axle hole. A center line of the round axle coincides with the swing center. FIG. 17D shows the state of the round axle which is fixed on the hydraulic gate support pier is set by being inserted into the long axle hole which is fixed on the gate leaf. For reference, the longer diameter of the long axle hole coincides with direction by which pitching motion of the gate leaf around the end support mechanism is allowed and the diameter in the direction of restricting gate leaf rolling which is at right angle motion to the pitching is just a bit bigger than the round axle diameter so that the impact load and hydraulic load working on the gate leaf during completely closed term may be supported by the end support key and the end support bracket.
(45) The gate leaf during swing motion floats on water only by the backup buoyancy of the operation tank which is shown on FIG. 6. Water of the same quantity as the backup buoyancy (1126 tf) is poured into the operation tank after gate leaf 7 of FIG. 4 arrives at the position of the gate leaf 6 in completely closed state, then the tank buoyancy—the pulling-up force S=9000 tf which consorts with the gate leaf weight W. If the gate leaf 7 is softly pushed down in this instant of time a free end of the gate leaf 7 starts to sink, the friction shoe 13 on FIG. 4 arrives at a water bottom (the bottom mounting), and the gate leaf 7 is fit in the position of the gate leaf 6 on FIG. 4. A load of the friction shoe 13 in this state is zero. The load of friction shoe 13 becomes 1074 tf when additional water quantity poured into the operation tank arrives at the tank buoyancy (1074 tf). Although overturn moment of the gate leaf 6 at this time is linear to the shoe load, overturn of the gate leaf 6 will be avoided without the aid of the upright moment of pulling-up force S since the overturn is restricted by the round axle of FIG. 17 (corresponding to previously mentioned “Problem 1: Gate leaf stability at gate mounting on a water bottom”).
(46) Pendulum of the gate leaf during its swing motion in ocean waves is rolling, pitching, dipping etc. The pendulum motion of the gate leaf has a rotation element and a removing element at a support point of the swing center support mechanism 11. Although the removing element is restricted by the support point of the three axes direction moving constraint, the rotation element of the pitching is not restricted by the support point of the two axes direction rotation free and a part of the dipping is transferred to a pitching motion. Although big rolling is restricted by the round axle of FIG. 17 whose impact on structural strength may slightly increase, the impact can be mitigated by an appropriate consideration since restriction force of the rolling is small (corresponding to previously mentioned “Problem 2: Gate leaf motion at gate open and closure operation”).
(47) Although an inclination moment works on the gate leaf due to a coupling of the horizontal component of the tide difference Δ h and the shoe friction force and a coupling of the vertical component of the tide difference Δ h and the shoe reaction force when the gate leaf is operated with the aid of the tide difference Δ h, the gate leaf removes up to the completely closed position keeping upright state since a big inclination is restricted by the round axle of FIG. 17 (corresponding to previously mentioned “Problem (3.1): Gate leaf lateral inclination”).
Embodiment 3
(48) FIG. 18 shows an example of the bottom support seat which provides both flexibility and high strength. FIG. 18A illustrates relative position of the bottom support seat and the gate leaf bottom. FIG. 18B is the detail A of FIG. 18A. FIG. 18C is BB section of FIG. 18B.
(49) A gate leaf portion which hits the concrete structure of the port side sea bottom is the bottom support seat when the gate leaf is operated with the aid of the tide difference Δh and the support seat is subject to a impact power created by a start of gate leaf section rotation at once after the hitting and the reaction force associated with transformation of kinetic energy to strain energy. The reaction force correspond to the inertia force and start by zero and arrives at its maximum value when the energy transformation completes. The support seat needs flexibility as well as high strength owing to accept forces of different kinds. FIG. 18B illustrates the state that a still material like steel etc. is embedded in a flexible material like rubber etc. FIG. 18C illustrates the state that the flexible material and the stiff material continue in a gate leaf length direction. The support seat keeps the flexibility due to this construction. When a flexible material is subject a compression, the inside flexible material surrounded by stiff material approaches to a state of three axial stress (hydrostatic stress). Material has a tendency to get higher yield point when its stress distribution approaches to a status of the hydrostatic stress. For instance, this phenomena is a back ground of a roller and a rail whose contact surface stress is bigger than their braking strength. The impact power created by a start, of gate leaf section rotation is mitigated by the flexibility of the initial stage of the hitting and the big reaction force of the inertia force is absorbed by the high strength after compressed (corresponding to previously mentioned “Problem 4: Reaction force and impact force on a gate leaf bottom support seat”).
EXPLANATION OF REFERENCE NUMERALS
(50) 1: gate leaf (solid line, in a completely closed state) (flap) 2: gate leaf (dotted line, in a completely opened state) (flap) 3: rotation center (flap) 4: concrete structure (flap) 5: wood seat (flap) 6: gate leaf (solid line, in a completely closed state) (swing) 7: gate leaf (dotted line, in a completely opened state) (swing) 8: swing center 9: storage pier (swing) 10: center line of the tidal sluice gate (swing) 11: swing center support mechanism 12: side thruster 13: friction shoe 14: upper (friction shoe) 15: wear-resistant material (friction shoe) 16: bottom support seat (sealing) 17: tip (wear-resistant material) 18: are radius (tip)
