Magnetic grid type dislocation meter for measuring displacement between concrete panel and cushion layer and measuring method

Abstract

The invention provides a magnetic grid type dislocation meter for measuring displacement between a concrete panel and a cushion layer and a measuring method of the magnetic grid type dislocation meter. The magnetic grid type dislocation meter comprises a stainless steel cylinder, a magnetic grid sensor, a rotating shaft, a metal pull rope and a sliding guide rod. The stainless steel cylinder is a solid cylinder, a rotating shaft is fixed at the leftmost end in the stainless steel cylinder, a metal pull rope is wound on the rotating shaft, and a magnetic grid sensor is fixed at the top of the rotating shaft; a sliding guide rod is arranged at the rightmost end in the stainless steel cylinder, one end of the sliding guide rod is connected with a metal pull rope, the other end of the sliding guide rod extends out of the stainless steel cylinder to be fixedly connected with a horizontal connecting rod, and the connecting rod is fixedly connected with a first anchor rod or an anchor plate through a universal joint. A horizontal connecting rod is fixedly connected to the outer wall of the left end of the stainless steel cylinder and connected with the second anchor rod or the anchor plate through a universal joint. During measurement, the magnetic grid type dislocation meter is embedded in a cushion layer, the first anchor rod extends into the cushion layer, the second anchor rod extends into the panel, and the relative displacement between the panel and the cushion layer is measured by calculating the displacement amount of the metal pull rope.

Description

Technical Field

[0001] The present invention relates to a magnetic grating dislocation meter for measuring the relative displacement between a concrete face rockfill dam face plate and a cushion layer and a measurement method for measuring the relative displacement between a concrete face rockfill dam face plate and a cushion layer using the magnetic grating dislocation meter. The present invention belongs to the technical field of water conservancy and hydropower engineering monitoring. Background Art

[0002] Concrete face rockfill dam is mainly composed of rockfill area, transition area, cushion area and face plate from inside to outside. It is an important dam type in my country's water conservancy and hydropower projects. During the construction period and long-term operation of concrete face rockfill dam, due to factors such as earthquakes, water level changes, climate change, etc., the dam body itself deforms, the dam body settles, the face plate shrinks and expands, and the dam slope constrains the face plate. Changes, such as the change, make the interface between the concrete face plate and the cushion layer below produce relative sliding / relative displacement, and then cause structural problems such as cracking and extrusion damage of the concrete face plate. Since the concrete face plate is constrained by the dam body, the cumulative effect of the relative displacement between the concrete face plate and the cushion layer may also cause the stress and strain of the face plate to exceed the standard, thereby causing destructive consequences such as cracking and crushing of the face plate. If the deformation of the face plate of the concrete face rockfill dam and the relative displacement between the face plate and the cushion layer cannot be discovered and handled in time, it is very likely to cause damage to the dam body or even collapse, resulting in serious consequences. Therefore, effective monitoring of the deformation and relative displacement between the face plate and the cushion layer of the concrete face rockfill dam is of vital significance to ensure the safe operation of the concrete face rockfill dam.

[0003] However, due to the lack of effective monitoring instruments and equipment in the existing technology, it is difficult to measure the relative displacement between the concrete panel and the cushion layer, and there are problems such as monitoring blind spots, discontinuous data collection, insufficient monitoring accuracy, and inability to obtain deformation during the water storage period. These problems limit the effectiveness of the dam safety monitoring system in practical applications and pose certain risks to dam safety management.

[0004] In addition, ordinary technicians in this field currently have insufficient understanding of the relative sliding process between the concrete face plate and the cushion layer, and lack of monitoring of the relative sliding between the concrete face plate and the cushion layer, which also seriously restricts the safety evaluation and risk assessment of concrete face rockfill dams. Summary of the invention

[0005] In order to overcome the deficiencies of the prior art, the present invention aims to provide a magnetic grating dislocation meter for measuring the relative displacement between a face plate and a cushion layer of a concrete face rockfill dam.

[0006] Another object of the present invention is to provide a method for measuring the relative displacement between a concrete face plate and a cushion layer using a magnetic grating dislocation meter, and to use the magnetic grating dislocation meter to perform high-precision, real-time, and comprehensive monitoring of the dislocation between the face plate and the cushion layer interface of a concrete face rockfill dam.

[0007] To achieve the above object, the present invention adopts the following technical scheme: a magnetic grating dislocation meter for measuring the displacement between a concrete panel and a cushion layer, which comprises a stainless steel cylinder, a magnetic grating sensor, a rotating shaft, a metal pull rope, and a sliding guide rod;

[0008] The stainless steel cylinder is a solid cylinder, and its interior is divided into three areas from left to right, namely, area I, area II and area III; a cavity is drilled in area I, in which the rotating shaft is fixed, the metal pull rope is wound around the rotating shaft, and the magnetic grating sensor is fixed on the top of the rotating shaft; an inner guide groove is provided in area III, in which the sliding guide rod is horizontally placed, one end of the sliding guide rod is connected to the metal pull rope, and the other end extends out of the stainless steel cylinder and is fixedly connected to a horizontally placed first connecting rod, and the first connecting rod is fixedly connected to the first anchor rod or anchor plate through a universal joint; the metal pull rope is located in area II, one end of which is wound around the rotating shaft in area I, and the other end is fixedly connected to the sliding guide rod in area III;

[0009] A second horizontally placed connecting rod is fixedly connected to the outer wall of one end of the stainless steel cylinder close to region I, and the second connecting rod is connected to the second anchor rod or anchor plate through a universal joint;

[0010] The metal pull rope, the sliding guide rod, the first connecting rod and the second connecting rod are coaxial.

[0011] Preferably, the rotating shaft is composed of a cylinder and a metal sleeve sleeved on the cylinder, and the magnetic grating sensor is fixed on the top of the metal sleeve.

[0012] Preferably, a waterproof rubber ring is fixed at the end of the inner guide groove of the stainless steel cylindrical area III, a small through hole is provided at the center of the waterproof rubber ring, and the metal pull rope passes through the through hole to be connected to the sliding guide rod.

[0013] Preferably, the through hole in the stainless steel cylindrical area II for passing the metal pull rope is filled with engine oil; and the surface of the magnetic grating sensor is infiltrated with epoxy resin glue for waterproofing.

[0014] Preferably, the displacement range of the magnetic grating sensor needs to meet 50-1000mm, and its accuracy is 0.05mm.

[0015] The method for measuring the displacement between a concrete panel and a cushion layer by using a magnetic grating dislocation meter comprises:

[0016] Make a magnetic grid dislocation meter;

[0017] A blind hole for placing an anchor rod or an anchor plate is drilled in the slope surface of the cushion layer of the concrete face rockfill dam, a first anchor rod or an anchor plate is inserted therein, grouting is poured into the blind hole, and an anchor end is formed after the cement solidifies;

[0018] A pit for burying the magnetic grating dislocation meter is dug at the interface of the cushion layer, and the magnetic grating dislocation meter is buried therein; a horizontally placed first connecting rod connected to the sliding guide rod of the magnetic grating dislocation meter is rigidly connected to the first anchor rod or anchor plate buried in the blind hole through a universal joint;

[0019] A second connecting rod placed horizontally near one end of the magnetic grating sensor of the magnetic grating dislocation meter is connected to a second anchor rod or an anchor plate through a universal joint, and the second anchor rod or the anchor plate is extended perpendicularly from the cushion layer slope surface to the panel;

[0020] Fill the residual space of the cushion pit with flexible material, fix the magnetic grating dislocation meter in the cushion, and ensure that the sliding guide rod can slide under the action of traction;

[0021] After the magnetic grating dislocation meter is installed, the concrete panel is poured. After the concrete has initially set, the initial value of the magnetic grating dislocation meter is read. During long-term monitoring, the monitoring value is obtained in real time. The difference between the monitoring value and the initial value is the relative displacement between the concrete panel and the cushion layer.

[0022] In the above measurement method, preferably, the metal pull rope and sliding guide rod inside the magnetic grid dislocation meter are coaxially arranged with the first connecting rod and the second connecting rod.

[0023] In the above measurement method, preferably, the length of the second anchor rod or anchor plate extending out of the slope of the cushion layer is 10cm-15cm.

[0024] The present invention provides equipment and methods for accurately monitoring, analyzing and evaluating the relative displacement between the concrete face plate and the cushion layer, and provides accurate and reliable data for preventing and reducing the cracking of the concrete face plate rockfill dam face plate. The present invention can be extended to the safety monitoring of concrete structures such as transportation engineering, port engineering, and geotechnical engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the magnetic grating dislocation meter of the present invention;

[0026] Figure 2 This is a schematic diagram of the installation of the magnetic grid type dislocation meter of the present invention (I);

[0027] Figure 3 This is a schematic diagram of the installation of the magnetic grid type dislocation meter of the present invention (II);

[0028] Figure 4 This is a schematic diagram of the installation of the magnetic grid type dislocation meter of the present invention (III);

[0029] Figure 5 This is a schematic diagram of the installation of the magnetic grid type dislocation meter of the present invention (IV). DETAILED DESCRIPTION

[0030] The structure and features of the present invention are described in detail below in conjunction with the accompanying drawings and embodiments. It should be noted that various modifications can be made to the embodiments disclosed herein, and therefore, the embodiments disclosed in the specification should not be regarded as limiting the present invention, but are merely examples of embodiments, the purpose of which is to make the features of the present invention obvious.

[0031] like Figure 1 As shown, the magnetic grating dislocation meter for measuring the relative displacement between the face plate and cushion layer of a concrete face rockfill dam of the present invention comprises a stainless steel cylinder 1, a magnetic grating sensor 2, a rotating shaft 3, a metal pull rope 4, a sliding guide rod 5, a connecting rod 6, a universal joint 7, and an anchor rod or an anchor plate 8.

[0032] The stainless steel cylinder 1 is a solid cylinder, and its interior is divided into three areas from left to right, namely, area I, area II and area III. A cavity is drilled in area I, and a rotating shaft 3 is fixed in the cavity. A metal pull rope 4 is wound around the rotating shaft 3, and a magnetic grating sensor 2 is fixed on the top of the rotating shaft. When the metal pull rope 4 is pulled to rotate the rotating shaft 3, the magnetic grating sensor 2 detects the angle of rotation of the rotating shaft and calculates the displacement of the metal pull rope 4. The rotating shaft 3 is composed of a cylinder and a metal sleeve sleeved on the cylinder, and the magnetic grating sensor 2 is fixed on the top of the metal sleeve.

[0033] An inner guide groove is provided in area III, in which a sliding guide rod 5 is horizontally placed, one end of the sliding guide rod 5 is connected to a metal pull rope 4, and the other end extends out of a stainless steel cylinder 1 and is fixedly connected to a horizontal connecting rod 6, and the connecting rod 6 is fixedly connected to an anchor rod or an anchor plate 8 through a universal joint 7. The sliding guide rod 5 can slide freely and unhindered in the inner guide groove.

[0034] The metal pull rope 4 is located in the area II, one end of which is wound around the rotating shaft 3 in the area I, and the other end is fixedly connected to the sliding guide rod 5 in the area III.

[0035] The left end of the stainless steel cylinder 1 , ie, the end close to the region I, is also fixedly connected with a horizontal connecting rod 6 , and the connecting rod 6 is connected with an anchor rod or an anchor plate 8 through a universal joint 7 .

[0036] During assembly, the metal pull rope 4, the sliding guide rod 5 and the connecting rods 6 at both ends of the stainless steel cylinder 1 are coaxial.

[0037] The present invention uses a magnetic grating dislocation meter to measure the relative displacement between the face plate and cushion layer of a concrete face rockfill dam:

[0038] First, a magnetic grating dislocation meter is made;

[0039] Then, if Figure 2 As shown, a blind hole 10 for placing an anchor rod or an anchor plate 8 is drilled in the slope surface 9 of the cushion layer of the concrete panel rockfill dam, the anchor rod or the anchor plate 8 is inserted therein, grout is poured into the blind hole, and an anchor end is formed after the cement solidifies;

[0040] like Figure 3 As shown, a pit 11 for burying a magnetic grating dislocation meter is dug at the interface of the cushion layer, and a magnetic grating dislocation meter 12 is buried therein; a horizontal connecting rod 6 connected to the sliding guide rod 5 of the magnetic grating dislocation meter is rigidly connected to an anchor rod or an anchor plate 8 buried in a blind hole 10 through a universal joint 7;

[0041] like Figure 4 As shown, the horizontal connecting rod 6 of the magnetic grating dislocation meter 12 near the end of the magnetic grating sensor 2 is connected to another anchor rod or anchor plate 8 through a universal joint 7, and the anchor rod or anchor plate 8 is extended perpendicularly to the cushion slope 9 and pointed to the panel 13, as shown in FIG. Figure 5 As shown; the length of the anchor rod extending out of the slope of the cushion layer is preferably 10cm-15cm;

[0042] Fill the residual space of the cushion layer pit 11 with a flexible material such as bentonite, fix the magnetic grating dislocation meter 12 in the cushion layer, and ensure that the sliding guide rod can slide under the action of traction;

[0043] After installing the magnetic grating dislocation meter, pour the concrete panel into the silo. Figure 5 As shown, after the initial setting of the concrete, the initial value of the magnetic grating dislocation meter is read, and in long-term monitoring, the monitoring value is obtained in real time. The difference between the monitoring value and the initial value is the relative displacement between the concrete panel and the cushion layer.

[0044] In order to meet the need for relative displacement between the concrete face rockfill dam face and cushion layer, the displacement range of the magnetic grating sensor must meet 50-1000mm, and its accuracy must be 0.05mm.

[0045] like Figure 1 As shown, at the boundary side between area III and area II, a waterproof rubber ring 14 is fixed to the end of the inner guide groove, and a small through hole is provided at the center of the waterproof rubber ring, through which the metal pull rope 4 passes to connect with the sliding guide rod 5.

[0046] In addition, the through hole in the stainless steel cylindrical area II for passing the metal pull rope is filled with engine oil as a waterproof material to prevent external water from entering area I through the gap between the sliding guide rod and the inner guide groove, the small hole of the waterproof rubber ring and the gap between the pull rope, and affecting the normal operation of the magnetic grating sensor 2; at the same time, the outer shell of the magnetic grating sensor 2 is also soaked with epoxy resin glue for waterproofing.

[0047] The present invention measures the relative displacement between the face plate and cushion layer of a concrete face rockfill dam as follows: when an anchor rod or an anchor plate end buried in the cushion layer and connected to a sliding guide rod undergoes a displacement and sliding L, the sliding guide rod pulls a metal pull rope to extend it, and the metal pull rope drives a rotating shaft to rotate, and a magnetic grating sensor fixed above the rotating shaft rotates synchronously, and the magnetic grating sensor reads the rotation angle α of the rotating shaft, and calculates the displacement and sliding amount of the anchor rod end connected to the sliding guide rod according to the radius r of the rotating shaft as L=πrα / 180, that is, the relative displacement amount between the face plate and cushion layer of the concrete face rockfill dam.

[0048] The magnetic grating dislocation meter and the measuring method for measuring the relative displacement between the concrete panel and the cushion layer of the present invention have the following advantages compared with the traditional measuring device and the measuring method:

[0049] 1. The present invention has the advantages of high monitoring accuracy, long service life, good temperature sensitivity, etc. It is particularly suitable for water conservancy and hydropower engineering structures with high monitoring accuracy requirements. The multiple waterproof structures arranged inside can meet the underwater monitoring needs of the dam during the water storage period. It can be applied to concrete structures with cement hydration heat release and obvious temperature changes.

[0050] 2. The present invention directly connects the metal pull rope with the sliding guide rod to directly convert the relative displacement between the concrete panel rockfill dam panel and the cushion layer into the sliding distance of the sliding guide rod. Without going through a conversion and amplification mechanism, the metal pull rope is pulled out by the sliding guide rod and rotated with the rotating shaft to directly calculate the relative displacement, thereby reducing the measurement error and reducing the calibration process of the magnetic grating dislocation meter before leaving the factory.

[0051] 3. The present invention installs the main body of the magnetic grating dislocation meter in the cushion layer and only buries anchor rods in the concrete panel to monitor the relative displacement between the panel and the cushion layer, thereby avoiding the impact on the concrete panel of the dam and ensuring the quality of the concrete panel.

[0052] Finally, it should be noted that the above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A magnetic grating dislocation meter for measuring the displacement between a concrete panel and a cushion layer, characterized in that: It includes a stainless steel cylinder, a magnetic grating sensor, a rotating shaft, a metal pull rope, and a sliding guide rod; The stainless steel cylinder is a solid cylinder, and its interior is divided into three areas from left to right, namely, area I, area II and area III; a cavity is drilled in area I, in which the rotating shaft is fixed, the metal pull rope is wound around the rotating shaft, and the magnetic grating sensor is fixed on the top of the rotating shaft; an inner guide groove is provided in area III, in which the sliding guide rod is horizontally placed, one end of the sliding guide rod is connected to the metal pull rope, and the other end extends out of the stainless steel cylinder and is fixedly connected to a horizontally placed first connecting rod, and the first connecting rod is fixedly connected to the first anchor rod or anchor plate through a universal joint; the metal pull rope is located in area II, one end of which is wound around the rotating shaft in area I, and the other end is fixedly connected to the sliding guide rod in area III; A second horizontally placed connecting rod is fixedly connected to the outer wall of one end of the stainless steel cylinder close to region I, and the second connecting rod is connected to the second anchor rod or anchor plate through a universal joint; The metal pull rope, the sliding guide rod, the first connecting rod and the second connecting rod are coaxial.

2. The magnetic grating dislocation meter for measuring the displacement between the concrete panel and the cushion layer according to claim 1 is characterized in that: The rotating shaft is composed of a cylinder and a metal sleeve sleeved on the cylinder, and the magnetic grating sensor is fixed on the top of the metal sleeve.

3. The magnetic grating dislocation meter for measuring the displacement between the concrete panel and the cushion layer according to claim 2 is characterized in that: A waterproof rubber ring is fixed at the end of the inner guide groove of the stainless steel cylindrical area III, and a small through hole is arranged at the center of the waterproof rubber ring. The metal pull rope passes through the through hole and is connected to the sliding guide rod.

4. The magnetic grating dislocation meter for measuring the displacement between the concrete panel and the cushion layer according to claim 3 is characterized in that: The through hole in the stainless steel cylindrical area II for passing the metal pull rope is filled with engine oil; The surface of the magnetic grating sensor is soaked with epoxy resin glue for waterproofing.

5. The magnetic grating dislocation meter for measuring the displacement between the concrete panel and the cushion layer according to claim 4 is characterized in that: The displacement range of the magnetic grating sensor must meet 50-1000mm, and its accuracy is 0.05mm.

6. A method for measuring the displacement between a concrete panel and a cushion layer using the magnetic grating dislocation meter according to any one of claims 1 to 5, characterized in that: It includes: Make a magnetic grid dislocation meter; Drill a blind hole for placing a first anchor rod or an anchor plate in the slope surface of the cushion layer of the concrete face rockfill dam, insert the first anchor rod or the anchor plate into the blind hole, pour grout into the blind hole, and form an anchor end after the cement solidifies; A pit for burying the magnetic grating dislocation meter is dug at the interface of the cushion layer, and the magnetic grating dislocation meter is buried therein; A horizontally placed first connecting rod connected to the sliding guide rod of the magnetic grating dislocation meter is rigidly connected to a first anchor rod or an anchor plate buried in the blind hole through a universal joint; A second connecting rod placed horizontally near one end of the magnetic grid sensor in the magnetic grid type dislocation meter is connected to a second anchor rod or an anchor plate through a universal joint, and the second anchor rod or the anchor plate is extended perpendicularly to the cushion layer slope surface and pointed to the panel; Fill the residual space of the cushion pit with flexible material, fix the magnetic grating dislocation meter in the cushion, and ensure that the sliding guide rod can slide under the action of traction; After the magnetic grating dislocation meter is installed, the concrete panel is poured. After the concrete has initially set, the initial value of the magnetic grating dislocation meter is read. During long-term monitoring, the monitoring value is obtained in real time. The difference between the monitoring value and the initial value is the relative displacement between the concrete panel and the cushion layer.

7. The method for measuring displacement between a concrete panel and a cushion layer according to claim 6, characterized in that: The metal pull rope and the sliding guide rod inside the magnetic grid dislocation meter are coaxially arranged with the first connecting rod and the second connecting rod.

8. The method for measuring displacement between a concrete panel and a cushion layer according to claim 7, characterized in that: The length of the second anchor rod or anchor plate extending out of the cushion layer slope surface is 10cm-15cm.

Images