Device and method for maintaining water level in front of earth-rock dam model test dam

Abstract

The invention discloses a device and method for maintaining the water level in front of a dam in a model test of an earth-rock dam, which can automatically and constantly maintain the water level in front of the dam in the model test of an earth-rock dam. The device comprises a water level sensing device and a water discharge control device, wherein the water level sensing device comprises a base, a movable rod, an insulating rod, two conductive rods, and a floating ball, wherein the two conductive rods are respectively provided with conductive rings, and the middle part of the movable rod is a conductive section; the water discharge control device comprises a bottom plate, and an electromagnet, a three-way water pipe, a limit structure, and an armature arranged on the bottom plate; a water blocking piston and a water blocking connecting rod are arranged in a straight pipe of the three-way water pipe; a wire at one end of the electromagnet is connected to a power supply and a control switch in sequence, and a wire at the other end of the electromagnet is electrically connected to a conductive rod, and the other conductive rod is electrically connected to the control switch through an electric wire.

Description

Technical Field

[0001] The invention relates to the technical field of physical model test of earth-rock dam seepage, and in particular to a device and method for maintaining the water level in front of a dam in an earth-rock dam model test. Background Art

[0002] Conducting physical model tests of seepage in earth-rock dams is a common way to conduct related research. When studying related issues under constant head conditions, the water level in front of the dam model in the test must remain unchanged. The traditional artificial solution is to supply water at a large flow rate first, then drain water through reserved holes or water pumps, and then adjust the water supply to control the water level. This method is not only rough, time-consuming and labor-intensive, but also when the permeability coefficient of the dam changes (such as simulating the seepage damage test of the dam), it is impossible to keep the water level in front of the dam at the predetermined position in time according to the sudden change of seepage flow, thus affecting the simulation accuracy of the model and the test results; using a float valve controller or a float connecting rod device to automatically control the water level can overcome the shortcomings of the traditional method, but this method is only applicable to a certain constant water level or a small water level fluctuation range. It cannot meet the test conditions under a variety of different water level conditions at one time, which brings inconvenience to the development of the experiment and the research of the subject. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a device and method for maintaining the water level in front of a dam in a model test of an earth-rock dam, which can automatically and constantly maintain the water level in front of a dam in a model test of an earth-rock dam.

[0004] The object of the present invention is achieved in that:

[0005] A device for maintaining the water level in front of a dam for a model test of an earth-rock dam comprises a water level sensing device and a water discharge control device. The water level sensing device comprises a base, a support structure and a movable rod. The base is used to fix the water level sensing device on the earth-rock dam model. The support structure comprises an insulating rod erected on the base and two conductive rods arranged in parallel on the insulating rod. One end of the two conductive rods is fixed to the insulating rod by a movable fastener. The other ends of the two conductive rods are respectively provided with conductive rings. The movable rod is parallel to the insulating rod and is movably sleeved in the two conductive rings. The middle part of the movable rod is a conductive section. The rest of the movable rod is insulated. A floating ball is provided at the lower end of the movable rod for driving the movable rod to float on the water surface.

[0006] The water outlet control device comprises a bottom plate, and an electromagnet, a three-way water pipe, a limiting structure and an armature arranged on the bottom plate; one end of the straight pipe of the three-way water pipe is a water inlet, and the branch pipe end of the three-way water pipe is a water outlet. A water blocking piston and a water blocking connecting rod are sequentially arranged in the straight pipe of the three-way water pipe along the water inlet direction; the fixed end of the armature is hinged on the bottom plate, and the free end of the armature is hinged to the end of the water blocking connecting rod. The limiting structure is used to limit the first limit position and the second limit position of the armature. The electromagnet is used to adsorb the armature to move the armature to the first limit position. When the armature is located at the first limit position, the water blocking piston blocks the water inlet and the water outlet of the three-way water pipe to form a water blocking state. When the armature is located at the second limit position, the water inlet and the water outlet of the three-way water pipe are connected to form a water flowing state.

[0007] The wire at one end of the electromagnet is connected to the power supply and the control switch in sequence, the wire at the other end of the electromagnet is electrically connected to a conductive rod, and the other conductive rod is electrically connected to the control switch through an electric wire. When the upper end and the lower end of the conductive segment are in contact with the two conductive rings, the electromagnet, the two conductive rods, the two conductive rings, the conductive segment, the power supply and the control switch form a series circuit.

[0008] Preferably, the base is in an inverted U shape and is used to be clamped on the side wall of the earth-rock dam model. A plurality of bolts are threadedly matched on one side wall of the base. The plurality of bolts are evenly distributed along the longitudinal direction of the base. The screw end of each bolt extends between the two side walls of the base, and a contact plate for fitting the side wall is provided.

[0009] Preferably, a fixing block is provided at the upper end of the base, an insertion hole is provided on the fixing block, and the insulating rod is inserted and fixed in the insertion hole.

[0010] Preferably, the lower end of the movable rod is provided with an external thread; the floating ball is matched with the thread of the lower end of the movable rod.

[0011] Preferably, the limiting structure comprises two fixing pins, and the two fixing pins are arranged on both sides of the armature.

[0012] Preferably, the electromagnet, the three-way water pipe and the fixing pin are all fixed to the bottom plate by gluing.

[0013] Preferably, the electromagnet and the straight pipe of the three-way water pipe are parallel to each other.

[0014] A method for maintaining the water level in front of a dam in a model test of an earth-rock dam comprises the following steps:

[0015] S1. Install a water level sensing device and a water outflow control device on the side wall on the upstream side of the earth-rock dam model, so that the floating ball is placed on the bottom wall of the model groove of the earth-rock dam model;

[0016] S2, connect one end of the electromagnet wire to the power supply and the control switch, and strip the other end of the wire and wrap it around the far water end of a conductive rod; wrap the stripped wire around the far water end of another conductive rod, and connect the other end of the wire to the control switch;

[0017] S3, the water source is connected to the water inlet, the water flow pushes the water blocking piston and the water blocking connecting rod to move backward, and enters the model groove of the earth-rock dam model through the water outlet, and the floating ball and the movable rod begin to float vertically;

[0018] S4. When the water level in the model tank reaches the required water level for the test, adjust the position of the movable fastener so that the conductive rings at the water-proximal ends of the two conductive rods contact the upper and lower ends of the conductive segments of the movable rods, and the electromagnet, the two conductive rods, the two conductive rings, the conductive segments, the power supply and the control switch form a series circuit;

[0019] S5, turn on the control switch, the free end of the armature rotates toward the electromagnet, driving the water blocking piston and the water blocking connecting rod to move forward, forming a water blocking state, and the water outlet stops discharging water;

[0020] S6. As the water in the model tank seeps through the earth-rock dam to the downstream side, the water level begins to drop, the float and the movable rod move vertically downward, the series circuit is automatically disconnected, and the water pressure at the water inlet pushes the water blocking piston and the water blocking connecting rod to move backward, forming a water flow state, the water outlet resumes water discharge, and the free end of the armature turns to the side away from the electromagnet;

[0021] S7. When the water level in the model tank reaches the predetermined water level again, the series circuit is automatically closed, and the free end of the armature rotates toward the electromagnet, driving the water blocking piston and the water blocking connecting rod to move forward, and the water outlet stops discharging water;

[0022] S8. Automatically repeat steps S6 and S7 to maintain the water level in front of the earth-rock dam model test dam.

[0023] Preferably, after completing the test work under one water level condition, the control switch is turned off.

[0024] If the subsequent required water level is higher than the current water level, first manually push the water blocking piston and the water blocking connecting rod backward to make water flow out of the water outlet, and repeat steps S4 and S5 after reaching the predetermined water level, and finally the device automatically repeats steps S6 and S7;

[0025] If the subsequent required water level is lower than the current water level, drain the water manually first, and repeat steps S4 and S5 after reaching the predetermined water level. Finally, the device automatically repeats steps S6 and S7.

[0026] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0027] The device and method of the present invention provide a simple, convenient and efficient way to automatically and constantly maintain the water level in front of the dam in the earth-rock dam model test; it not only overcomes the shortcomings of the existing methods, but also can meet the test condition requirements under a variety of different water level conditions at one time, which is conducive to the development of related research work. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of a water level sensing device of the present invention.

[0029] Figure 2 It is a schematic diagram of the water outlet control device of the present invention.

[0030] Figure 3 It is a schematic diagram of the device of the present invention installed on the side wall of the earth-rock dam model test.

[0031] Attached photos

[0032] In the accompanying drawings, there are long rod bolt 1 (bolt), contact disc 2 (contact disc), base 3, PVC pipe 4 (insulating rod), right angle fastener 5 (movable fastener), horizontal steel pipe 6 (conductive rod), copper sheet 7 (conductive section), iron ring 8 (conductive ring rod), movable rod 9, float 10, fixed iron block 11 (fixed block), three-way water pipe 12, water blocking piston 13, water outlet 14, water blocking connecting rod 15, movable hinge 16, fixed latch 17 (limiting structure), rotary hinge support 18, strong armature 19 (armature), winding coil 20 (electromagnet component), iron core 21 (electromagnet component), glass plate 22 (bottom plate), water inlet 23, model drainage hole 24, side wall 25, water outlet control device 26, water level sensing device 27, earth and rock dam model 28, wire 29, control switch 30, power supply 31. DETAILED DESCRIPTION

[0033] See also Figure 1-Figure 3, a device for maintaining the water level in front of the earth-rock dam model test dam, including a water level sensing device 27 and a water discharge control device 26, wherein the water level sensing device 27 includes a base 3, a supporting structure, a movable rod 9 and a floating ball 10. The base 3 is welded into an inverted U shape by two vertical steel plates and a horizontal steel plate, and one of the vertical steel plates is provided with three horizontally distributed holes with internal threads and a long rod bolt 1, and a contact disc 2 is welded at the tail of the long rod bolt 1; a fixed iron block 11 with a vertical circular hole (insertion hole) is welded on the horizontal steel plate. The supporting structure is composed of a PVC pipe 4 and two horizontal steel pipes 6, the PVC pipe 4 is inserted into the fixed iron block 11, and the two horizontal steel pipes 6 are connected to the PVC pipe through a right-angle fastener 5, and a horizontal iron ring 8 is welded at the water-side end of the two horizontal steel pipes 6. The movable rod 9 is made of light plastic, and its cross-sectional diameter is 3 mm smaller than the inner diameter of the horizontal iron ring 8. The upper part of the movable rod 9 is wrapped with a copper sheet 7, and the lower end of the movable rod 9 is provided with an external thread. The floating ball 10 is made of plastic and is provided with a round hole with an internal thread.

[0034] The water outlet control device 26 includes a glass plate 22, an electromagnet, a three-way water pipe 12, a fixed pin 17, a water blocking piston 13, a water blocking connecting rod 15 and a strong armature 19. The electromagnet, the three-way water pipe 12 and the fixed pin 17 are all fixed to the glass plate 22 by glue. The inside of the three-way water pipe 12 is provided with a water blocking piston 13 and a water blocking connecting rod 15 along the water inlet direction. The electromagnet is arranged in parallel along the water inlet direction, and a strong armature 19 arranged perpendicularly thereto is provided at one end. One end of the strong armature 19 is provided with a rotating hinge support 18, and the other end is connected to the water blocking connecting rod 15 through a movable hinge 16; fixed pins 17 are provided on both sides of the strong armature 19, and the net spacing between the pins is equal to the diameter of the water outlet pipe. The water blocking connecting rod 15 adopts an elastic rod, which can produce a certain deformation to adapt to the movement path. The axial length of the water blocking piston 13 can block the branch pipe (the position is shown in the figure) to prevent water leakage and achieve the purpose of water blocking. At the same time, in order to obtain a better water blocking effect, the piston can consider using a silicone water blocking piston.

[0035] A method for maintaining the water level in front of a test dam of an earth-rock dam model 28 comprises the following steps:

[0036] (1) A water level sensing device 27 is installed on the side wall 25 on the upstream side of the test tank of the earth-rock dam model 28. One of the vertical steel plates on the base 3 is placed close to the inner surface of the side wall 25. The long-rod bolt on the other vertical steel plate of the base 3 is tightened so that the contact disc 2 at the tail of the bolt is placed close to the outer surface of the side wall 25. The movable rod 9 is passed through two horizontal iron rings 8, and the lower end of the movable rod 9 is tightened with the floating ball 10 so that the movable rod 9 and the floating ball 10 are placed vertically on the bottom surface of the model tank as a whole.

[0037] (2) Adhere the water outlet control device 26 to the surface of the base 3 of the water level sensing device 27, connect one end of the coil 20 wound on the iron core 21 to the power supply 31 and the control switch 30, and strip the other end and wrap it around the far water end of a horizontal steel pipe 6; wrap the stripped wire 29 around the far water end of another horizontal steel pipe 6, and connect the other end of the wire 29 to the control switch 30.

[0038] (3) A low-pressure water source is connected to the water inlet 23 of the water outlet control device 26. After the water flow fills the water pipe, it pushes the water blocking piston 13 and the water blocking connecting rod 15 in the pipe to move backward and enter the model tank through the water outlet 14. The float 10 and the movable rod 9 begin to float vertically.

[0039] (4) When the water level in the model tank reaches the required water level for the test, adjust the position of the right-angle fastener 5 so that the horizontal iron ring 8 at the water-proximal end of the two horizontal steel pipes 6 just contacts the upper and lower edges of the copper sheet 7 wrapped on the movable rod 9, and the winding coil 20 wound on the iron core 21, the two horizontal steel pipes 6, the two horizontal iron rings 8, the copper sheet 7, the power supply 31 and the control switch 30 form a series circuit.

[0040] (5) Turn on the control switch 30, the strong armature 19 rotates toward the side of the iron core 21, driving the water blocking piston 13 and the water blocking connecting rod 15 to move forward, and the water outlet 14 stops discharging water.

[0041] (6) As the water in the model tank seeps through the earth-rock dam body to the downstream side, the water level begins to drop, the float 10 and the movable rod 9 move vertically downward, the circuit in step (4) is automatically disconnected, the water pressure at the water inlet 23 pushes the water blocking piston 13 and the water blocking connecting rod 15 to move backward, and the water outlet 14 resumes water discharge. The strong armature 19 turns to the side away from the iron core 21.

[0042] (7) When the water level in the model tank reaches the predetermined water level again, the circuit in step (4) is automatically closed, and the strong armature 19 rotates toward the side of the iron core 21, driving the water blocking piston 13 and the water blocking connecting rod 15 to move forward, and the water outlet 14 stops discharging water.

[0043] (8) The device automatically repeats steps (6) and (7) to maintain the water level in front of the test dam of the earth-rock dam model 28.

[0044] (9) After completing the test work under one water level condition, close the control switch 30. When the subsequent required water level is higher than the current water level, first manually push the water blocking piston 13 and the water blocking connecting rod 15 backward to make the water outlet 14 discharge water. After reaching the predetermined water level, repeat steps (4) and (5). Finally, the device automatically repeats steps (6) and (7). When the subsequent required water level is lower than the current water level, first manually drain the water. After reaching the predetermined water level, repeat steps (4) and (5). Finally, the device automatically repeats steps (6) and (7).

[0045] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A device for maintaining the water level in front of a dam for a model test of an earth-rock dam, characterized in that: It comprises a water level sensing device and a water outlet control device. The water level sensing device comprises a base, a supporting structure and a movable rod. The base is used to fix the water level sensing device on the earth-rock dam model. The supporting structure comprises an insulating rod erected on the base and two conductive rods arranged in parallel on the insulating rod. One end of the two conductive rods is fixed to the insulating rod by a movable fastener. The other ends of the two conductive rods are respectively provided with conductive rings. The movable rod is parallel to the insulating rod and is movably sleeved in the two conductive rings. The middle part of the movable rod is a conductive section. The rest of the movable rod is insulated. The lower end of the movable rod is provided with a floating ball, which is used to drive the movable rod to float on the water surface. The water outlet control device comprises a bottom plate, and an electromagnet, a three-way water pipe, a limiting structure and an armature arranged on the bottom plate; one end of the straight pipe of the three-way water pipe is a water inlet, and the branch pipe end of the three-way water pipe is a water outlet. A water blocking piston and a water blocking connecting rod are sequentially arranged in the straight pipe of the three-way water pipe along the water inlet direction; the fixed end of the armature is hinged on the bottom plate, and the free end of the armature is hinged to the end of the water blocking connecting rod. The limiting structure is used to limit the first limit position and the second limit position of the armature. The electromagnet is used to adsorb the armature to move the armature to the first limit position. When the armature is located at the first limit position, the water blocking piston blocks the water inlet and the water outlet of the three-way water pipe to form a water blocking state. When the armature is located at the second limit position, the water inlet and the water outlet of the three-way water pipe are connected to form a water flowing state. The wire at one end of the electromagnet is connected to the power supply and the control switch in sequence, the wire at the other end of the electromagnet is electrically connected to a conductive rod, and the other conductive rod is electrically connected to the control switch through an electric wire. When the upper end and the lower end of the conductive segment are in contact with the two conductive rings, the electromagnet, the two conductive rods, the two conductive rings, the conductive segment, the power supply and the control switch form a series circuit.

2. The device for maintaining the water level in front of the earth-rock dam model test dam according to claim 1, characterized in that: The base is in an inverted U shape and is used to be clamped on the side wall of the earth-rock dam model. A plurality of bolts are threadedly fitted on one side wall of the base. The plurality of bolts are evenly distributed along the longitudinal direction of the base. The screw end of each bolt extends between the two side walls of the base, and a contact plate is provided for fitting the side wall.

3. The device for maintaining the water level in front of the earth-rock dam model test dam according to claim 1, characterized in that: A fixing block is arranged at the upper end of the base, an insertion hole is arranged on the fixing block, and the insulating rod is inserted and fixed in the insertion hole.

4. The device for maintaining the water level in front of the earth-rock dam model test dam according to claim 1, characterized in that: The lower end of the movable rod is provided with an external thread; the floating ball is matched with the thread at the lower end of the movable rod.

5. The device for maintaining the water level in front of the earth-rock dam model test dam according to claim 1, characterized in that: The limiting structure comprises two fixing pins, and the two fixing pins are arranged on both sides of the armature.

6. The device for maintaining the water level in front of the earth-rock dam model test dam according to claim 1, characterized in that: The electromagnet, the three-way water pipe and the fixed latch are all fixed on the bottom plate by gluing.

7. The device for maintaining the water level in front of the earth-rock dam model test dam according to claim 1, characterized in that: The electromagnet and the straight pipes of the three-way water pipe are parallel to each other.

8. A method for maintaining the water level in front of a dam in a model test of an earth-rock dam, characterized in that: The device for maintaining the water level in front of the earth-rock dam model test dam according to claim 1 is used. The steps include: S1. Install a water level sensing device and a water outflow control device on the side wall on the upstream side of the earth-rock dam model, so that the floating ball is placed on the bottom wall of the model groove of the earth-rock dam model; S2, connect one end of the electromagnet wire to the power supply and the control switch, and strip the other end of the wire and wrap it around the far water end of a conductive rod; wrap the stripped wire around the far water end of another conductive rod, and connect the other end of the wire to the control switch; S3, the water source is connected to the water inlet, the water flow pushes the water blocking piston and the water blocking connecting rod to move backward, and enters the model groove of the earth-rock dam model through the water outlet, and the floating ball and the movable rod begin to float vertically; S4. When the water level in the model tank reaches the required water level for the test, adjust the position of the movable fastener so that the conductive rings at the water-proximal ends of the two conductive rods contact the upper and lower ends of the conductive segments of the movable rods, and the electromagnet, the two conductive rods, the two conductive rings, the conductive segments, the power supply and the control switch form a series circuit; S5, turn on the control switch, the free end of the armature rotates toward the electromagnet, driving the water blocking piston and the water blocking connecting rod to move forward, forming a water blocking state, and the water outlet stops discharging water; S6. As the water in the model tank seeps through the earth-rock dam to the downstream side, the water level begins to drop, the float and the movable rod move vertically downward, the series circuit is automatically disconnected, and the water pressure at the water inlet pushes the water blocking piston and the water blocking connecting rod to move backward, forming a water flow state, the water outlet resumes water discharge, and the free end of the armature turns to the side away from the electromagnet; S7. When the water level in the model tank reaches the predetermined water level again, the series circuit is automatically closed, and the free end of the armature rotates toward the electromagnet, driving the water blocking piston and the water blocking connecting rod to move forward, and the water outlet stops discharging water; S8. Automatically repeat steps S6 and S7 to maintain the water level in front of the earth-rock dam model test dam.

9. A method for maintaining the water level in front of a dam in a model test of an earth-rock dam according to claim 8, characterized in that: After completing the test work under one water level condition, turn off the control switch. If the subsequent required water level is higher than the current water level, first manually push the water blocking piston and the water blocking connecting rod backward to make water flow out of the water outlet, and repeat steps S4 and S5 after reaching the predetermined water level, and finally the device automatically repeats steps S6 and S7; If the subsequent required water level is lower than the current water level, drain the water manually first, and repeat steps S4 and S5 after reaching the predetermined water level. Finally, the device automatically repeats steps S6 and S7.

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