Monitoring and filling device and method for expansion of karst soil cave around power transmission tower

Abstract

The invention discloses a monitoring and filling device and method for expansion of a karst soil cave around a power transmission tower, the monitoring and filling device comprises a control center and a plurality of pre-embedded devices, the plurality of pre-embedded devices are sequentially and coaxially arranged on the outer side of the tower with a tower foundation as the center and are all installed in a karst soil body, and each pre-embedded device comprises a plurality of pre-embedded assemblies; the multiple embedded assemblies surround the outer side of a tower in the circumferential direction, each embedded assembly comprises a hollow column, the hollow column is installed in karst soil and filled with calcium oxide powder, the first monitoring device and the second monitoring device are sequentially installed in the hollow column, and the third monitoring device is movably installed in the hollow column. The multiple pre-embedded devices are adopted, the pre-embedded devices surround the outer ring of the tower, all positions of the tower can be monitored, the flowing condition of calcium oxide can be judged by monitoring friction force, and therefore calcium oxide is supplemented so that expansion of a soil hole can be restrained, and the filling effect is good; meanwhile, the expansion condition of the soil hole can be monitored in real time, and the monitoring effect is good.

Description

Technical Field

[0001] The present invention relates to the technical field of transmission tower monitoring, and particularly to a monitoring and filling device and method for the expansion of karst soil caves around transmission towers. Background Art

[0002] In recent years, the construction field of transmission towers has developed rapidly. After the construction of transmission towers, there will be an expansion phenomenon of karst soil caves around them. Due to factors such as the expansion of karst soil caves, the foundation of the tower will deform. If not discovered and remedied in time, in severe cases, even collapse accidents may occur, ultimately resulting in serious economic losses. Therefore, it is necessary to monitor karst soil caves.

[0003] Currently, the monitoring methods for the expansion of karst soil caves include geological exploration technology, feature extraction technology, etc. However, they all require professional knowledge and skills, have high requirements for personnel, need professional knowledge for data processing and interpretation, and involve large investments in funds and equipment. The evaluation results may be affected by various factors and are not very accurate, and at the same time, it also leads to a poor filling effect of subsequent soil caves. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects and problems of poor monitoring effect and poor filling effect of karst soil caves in the prior art, and provide a monitoring and filling device and method for the expansion of karst soil caves around transmission towers with good monitoring effect and good filling effect.

[0005] To achieve the above purpose, the technical solution of the present invention is: a monitoring and filling device for the expansion of karst soil caves around a transmission tower, including a control center and a plurality of embedded devices. The plurality of embedded devices are arranged coaxially in sequence with the tower as the center on the outside of the tower foundation. The plurality of embedded devices are all installed in the karst soil body. The embedded device includes a plurality of embedded components. The plurality of embedded components are arranged around the outside of the tower in the circumferential direction. The embedded component includes a hollow column, a first monitoring device, a second monitoring device, and a third monitoring device. The hollow column is installed in the karst soil body and filled with calcium oxide powder. The first monitoring device and the second monitoring device are sequentially installed on the inner side wall of the hollow column. The third monitoring device is movably installed in the hollow column. The first monitoring device, the second monitoring device, and the third monitoring device are all connected to the control center;

[0006] The first monitoring device and the second monitoring device are used to respectively detect the friction force when the calcium oxide powder in the hollow column flows, and transmit the friction force to the control center;

[0007] The third monitoring device is used to monitor the heat generated after the reaction of calcium oxide powder with water to determine the shape of the soil cave;

[0008] The control center is used to determine whether the calcium oxide powder is exhausted and the expansion of the soil hole according to the friction force and determine the material required to fill the soil hole in combination with the shape of the soil hole monitored by the third monitoring device.

[0009] A first mounting hole and a second mounting hole are provided in the hollow column, a first hollow tube is installed in the first mounting hole, a second hollow tube is installed in the second mounting hole, the third monitoring device is movably connected to the first hollow tube, the first monitoring device and the second monitoring device are respectively installed on the inner wall of the second hollow tube, the calcium oxide powder is filled in the second hollow tube, a plurality of steel bars are connected to the outer peripheral surface of the hollow column, and the plurality of steel bars are all arranged in the karst soil body.

[0010] The third monitoring device includes a telescopic long rod and an infrared thermal imaging camera. The telescopic long rod is arranged in the first hollow tube, and the infrared thermal imaging camera is installed at the bottom of the telescopic long rod.

[0011] The first monitoring device includes a first friction sensor, and the second monitoring device includes a second friction sensor. The first friction sensor is installed at the middle of the inner wall of the second hollow tube, and the second friction sensor is installed at the bottom of the inner wall of the second hollow tube.

[0012] A monitoring and filling method for the expansion of karst soil holes around transmission towers, the monitoring and filling method is applied to a monitoring and filling device for the expansion of karst soil holes around transmission towers, and the monitoring and filling method comprises the following steps:

[0013] Step 1: Select the pole tower to be monitored, detect the soil hole under the pole tower, and determine the positions of multiple embedded devices according to the position and size of the soil hole;

[0014] Step 2: dig a pit at the determined position according to the depth of each embedded component, and place multiple embedded components in each embedded device into the processed deep pit along the circumferential direction with the tower as the center;

[0015] Step 3: installing the first monitoring device, the second monitoring device, and the third monitoring device in the hollow column, and filling the hollow column with calcium oxide powder so that the calcium oxide powder contacts the karst soil;

[0016] Step 4: The friction between the calcium oxide powder and the hollow column is monitored by the first monitoring device and the second monitoring device. The control center generates a friction curve graph based on the acquired friction data and determines whether the calcium oxide powder is exhausted and the expansion of the soil hole.

[0017] Step 5: The control center fills the soil cave according to whether the calcium oxide powder is exhausted and the expansion condition of the soil cave, in combination with the shape of the soil cave monitored by the third monitoring device.

[0018] The number of the embedded devices is four, and the four embedded devices are arranged in a circular staggered manner with the pole tower as the center. The specific steps for determining the positions of the multiple embedded devices in Step 1 are as follows:

[0019] Through numerical simulation by finite element simulation software, the critical expansion line function f of the soil cave is obtained. The positions of the four embedded devices are determined by multi-equal division according to the critical expansion line function f. The horizontal distances of the four embedded devices from the pole tower foundation are L 0 、L 2 、L 3 、L 1 , and the depths of the four embedded devices are H 0 、H 2 、H 3 、H 1 , and the calculation formulas are as follows:

[0020] f = αr 0 + βL + λH;

[0021]

[0022]

[0023] Among them, c, is the cohesion and internal friction angle of the soil layer, F and N are the tensile and compressive loads of the pole tower, r 0 is the radius of the soil cave, H is the vertical distance from the top of the soil cave to the ground surface, L is the horizontal distance from the top of the soil cave to the center of the bottom of the pole tower foundation, L 0 is the horizontal distance from the embedded device to the pole tower foundation when the soil cave appears directly below the pole tower foundation, H 0 is the depth of the embedded device when the soil cave appears directly below the pole tower foundation, H 1 is the depth of the embedded device at the arch point of the soil cave expansion line, L 1 is the horizontal distance from the embedded device at the arch point of the soil cave expansion line to the pole tower foundation.

[0024] In Step 4, generating the friction force curve graph includes:

[0025] The first monitoring device and the second monitoring device respectively collect the friction force change data at two different positions, namely the middle and the bottom of the calcium oxide powder and the hollow column, and transmit the data to the control center via wireless signals at a frequency of once per second. The control center forms two visualized change curves from the data to form the friction force curve graph.

[0026] In step four, judging whether the calcium oxide powder is exhausted and the expansion condition of the soil cave includes:

[0027] The control center calculates the slope change of each group with the collected friction change data grouped by 10s;

[0028] When the slope change trends of the first curve and the second curve are small floating fluctuations or stationary, it is within the allowable error range. At this time, the soil cave has no expansion and the calcium oxide powder is not exhausted;

[0029] When the slope change trend of the first curve is first small floating fluctuations or stationary, then increases rapidly, and then slowly decreases to zero, and the change trend of the second curve is the same as that of the first curve, at this time the soil cave expands to the bottom of the hollow column and the calcium oxide powder is about to be exhausted;

[0030] When the slope change trend of the first curve is first small floating fluctuations or stationary, then increases rapidly, and then drops suddenly to zero and there is no change for a long time; the change trend of the second curve is the same as that of the first curve, at this time the soil cave expands to the bottom of the hollow column and the calcium oxide powder has been exhausted.

[0031] In step five, filling treatment of the soil cave includes:

[0032] When the soil cave expands to the bottom of the hollow column and the calcium oxide powder is about to be exhausted, fill the hollow column with calcium oxide powder until the calcium oxide powder is flush with the upper end face of the hollow column;

[0033] When the soil cave expands to the bottom of the hollow column and the calcium oxide powder has been exhausted, find the corresponding hollow column, inject water into the hollow column, and at the same time detect the heat in the soil cave through the third monitoring device and determine the shape of the soil cave. The control center determines that the filling material of the soil cave is silicate material according to the shape of the soil cave, then insert a perfusion pipe into the hollow column, and flow the silicate material into the soil cave through the perfusion pipe. At this time, a large amount of calcium hydroxide is generated by the chemical reaction of the calcium oxide powder and water in the soil cave, and reacts with the added silicate material to generate calcium silicate gel to fill the soil cave.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] 1. In the monitoring and filling device and method for the expansion of karst soil caves around a transmission tower of the present invention, by using multiple embedded devices that surround the outer circle of the tower, monitoring can be carried out at various positions of the tower. By monitoring the friction force, the flow situation of calcium oxide can be judged, so as to supplement calcium oxide to inhibit the expansion of the soil cave. At the same time, the expansion situation of the soil cave can be monitored in real time. Since the reaction of calcium oxide with water will release heat, the shape of the soil cave can be determined by monitoring the heat, and the calcium hydroxide generated reacts with the oxygen in the soil cave to generate calcium carbonate to fill the soil cave. When the expansion of the soil cave is too large and calcium oxide cannot fill it, the shape of the soil cave is judged by the heat during the reaction of the soil cave, and appropriate filling and curing materials are selected according to the shape of the soil cave, and the filling effect is better. Therefore, the monitoring effect of the present invention is good and the filling effect is better.

[0036] 2. In the monitoring and filling device and method for the expansion of karst soil caves around a transmission tower of the present invention, by detecting the change of friction force data with a friction sensor, it can be quickly judged whether the karst soil cave has expanded to the vicinity of the tower and the consumption situation of the materials in the hollow column. By connecting both sides of the hollow column to the steel bars inserted into the soil, the settlement of the hollow column is avoided from affecting the monitoring effect. The infrared thermal imaging camera and the heat generated by the reaction of calcium oxide powder with the moisture in the soil cave are cleverly used to accurately draw the shape of the soil cave, and silicate materials are used to further carry out a material linkage reaction with the generated calcium hydroxide to fill the soil cave. At this time, due to the exothermic reaction of calcium oxide powder with water, the formation of gel substances is accelerated to fill the soil cave, and the cost is relatively low. Therefore, the present invention has low cost, good monitoring effect and better filling effect.

[0037] 3. In the monitoring device and method for the expansion of karst soil caves around a transmission tower of the present invention, using finite element software to simulate the initial critical line of soil cave expansion to determine the installation position of the embedded device will make the monitoring more accurate and reliable. At the same time, the positions of each embedded device are determined in combination with the critical line of soil cave expansion, so as to make the subsequent soil cave filling effect better. Through two friction force curve graphs, the flow situation of calcium oxide powder can be judged, and then the expansion situation of the soil cave can be judged, so that corresponding filling operations can be carried out according to the specific expansion situation of the soil cave. Therefore, the present invention is convenient to operate and has relatively high monitoring accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic structural diagram of a monitoring device for the expansion of karst soil caves around a transmission tower in the present invention.

[0039] Figure 2 It is a schematic structural diagram of the tower and the karst soil cave in the present invention.

[0040] Figure 3 It is a schematic structural diagram of the tower and the embedded components in the present invention.

[0041] Figure 4 It is a schematic structural diagram of the embedded component in the present invention.

[0042] Figure 5 It is a schematic structural diagram of the hollow column, the first hollow tube, and the second hollow tube in the present invention.

[0043] In the figure: tower pole 1, embedded device 2, embedded component 21, hollow column 211, first installation hole 212, second installation hole 213, first hollow tube 214, second hollow tube 215, steel bar 216, first monitoring device 3, first friction sensor 31, second monitoring device 4, second friction sensor 41, third monitoring device 5, telescopic long rod 51, infrared thermal imaging camera 52, control center 6, calcium oxide powder 7, soil cave 8, expansion critical line 9. Specific embodiments

[0044] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0045] Embodiment 1:

[0046] See Figures 1 to 5 , a monitoring and filling device for the expansion of karst soil caves around a transmission tower pole, comprising a control center 6 and a plurality of embedded devices 2. The plurality of embedded devices 2 are arranged coaxially in sequence with the tower pole as the center on the outside of the tower pole foundation 1. The plurality of embedded devices 2 are all installed in the karst soil body. The embedded device 2 includes a plurality of embedded components 21. The plurality of embedded components 21 are arranged around the outside of the tower pole in the circumferential direction. The embedded component 21 includes a hollow column 211, a first monitoring device 3, a second monitoring device 4, and a third monitoring device 5. The hollow column 211 is installed in the karst soil body and filled with calcium oxide powder 7. The first monitoring device 3 and the second monitoring device 4 are sequentially installed on the inner side wall of the hollow column 211. The third monitoring device 5 is movably installed in the hollow column 211. The first monitoring device 3, the second monitoring device 4, and the third monitoring device 5 are all connected to the control center 6;

[0047] The first monitoring device 3 and the second monitoring device 4 are used to respectively detect the friction force when the calcium oxide powder 7 flows in the hollow column 211 and transmit the friction force to the control center 6;

[0048] The third monitoring device 5 is used to monitor the shape of the soil cave 8 by determining the heat generated after the reaction of the calcium oxide powder 7 with water;

[0049] The control center 6 is used to judge whether the calcium oxide powder 7 is exhausted and the expansion situation of the soil cave 8 according to the friction force and determine the filling material required for the soil cave 8 in combination with the shape of the soil cave 8 monitored by the third monitoring device 5.

[0050] A first installation hole 212 and a second installation hole 213 are formed in the hollow column 211. A first hollow tube 214 is installed in the first installation hole 212, and a second hollow tube 215 is installed in the second installation hole 213. The third monitoring device 5 is movably connected to the first hollow tube 214. The first monitoring device 3 and the second monitoring device 4 are respectively installed on the inner side wall of the second hollow tube 215. The calcium oxide powder 7 is filled in the second hollow tube 215. A plurality of steel bars 216 are connected to the outer peripheral surface of the hollow column 211, and all the plurality of steel bars 216 are arranged in the karst soil body.

[0051] The third monitoring device 5 includes a telescopic long rod 51 and an infrared thermal imaging camera 52. The telescopic long rod 51 is arranged in the first hollow tube 214, and the infrared thermal imaging camera 52 is installed at the bottom of the telescopic long rod 51.

[0052] The first monitoring device 3 includes a first friction sensor 31, and the second monitoring device 4 includes a second friction sensor 41. The first friction sensor 31 is installed in the middle of the inner side wall of the second hollow tube 215, and the second friction sensor 41 is installed at the bottom of the inner side wall of the second hollow tube 215.

[0053] In this embodiment, the hollow column 211, the first hollow tube 214 and the second hollow tube 215 are made of steel with high friction and corrosion resistance, and their tops are slightly higher than the ground. The upper ends of the first hollow tube 214 and the second hollow tube 215 are made into detachable seals, and the lower ends are not sealed. The steel bars 216 are made of steel with high friction and corrosion resistance. When the third monitoring device 5 needs to be monitored, first use a flashlight to observe whether the bottom of the embedded hollow column 211 is connected to the soil cavity 8. If the infrared thermal imaging camera 52 can be directly inserted, no treatment is required. If there is no connection or the bottom is stuck with mud, construction workers need to use a steel pipe to penetrate the soil body through pipe fittings to ensure that the infrared thermal imaging camera 52 can smoothly penetrate into the soil cavity 8 for detection.

[0054] Embodiment 2:

[0055] See Figure 2 A monitoring and filling method for the expansion of karst soil cavities around a transmission tower. The monitoring and filling method is applied to the monitoring device for the expansion of karst soil cavities around the transmission tower in Embodiment 1. The monitoring and filling method includes the following steps:

[0056] Step 1: Select a tower to be monitored, detect the soil cavity 8 existing under the tower, and determine the positions of a plurality of embedded devices 2 according to the position and size of the soil cavity 8;

[0057] Step 2: Excavate pits at the determined positions according to the depth of each embedded component 21, and place multiple embedded components 21 in each embedded device 2 into the processed deep pits in a circumferential direction centered on the pole tower;

[0058] Step 3: Install the first monitoring device 3, the second monitoring device 4, and the third monitoring device 5 into the hollow column 211. At the same time, fill the hollow column 211 with calcium oxide powder 7 so that the calcium oxide powder 7 contacts the karst soil mass;

[0059] Step 4: Monitor the friction force between the calcium oxide powder 7 and the hollow column 211 through the first monitoring device 3 and the second monitoring device 4. The control center 6 generates a friction force curve graph based on the obtained friction force data, and judges whether the calcium oxide powder 7 is exhausted and the expansion situation of the soil cavity 8;

[0060] Step 5: The control center 6 performs filling treatment on the soil cavity 8 according to whether the calcium oxide powder 7 is exhausted and the expansion situation of the soil cavity 8, in combination with the shape of the soil cavity 8 monitored by the third monitoring device 5.

[0061] The number of the embedded devices 2 is four, and the four embedded devices 2 are arranged in a circular staggered manner centered on the pole tower. The specific steps for determining the positions of the multiple embedded devices 2 in Step 1 are as follows:

[0062] Perform numerical simulation through finite element simulation software to obtain the expansion critical line function f of the soil cavity 8. Determine the positions of the four embedded devices 2 according to the expansion critical line function f by multi-equal division. The horizontal distances of the four embedded devices 2 from the pole tower foundation 1 are L 0 、L 2 、L 3 、L 1 , and the depths of the four embedded devices 2 are H 0 、H 2 、H 3 、H 1 , and the calculation formula is as follows:

[0063] f = αr 0 + βL + λH;

[0064]

[0065] Among them, c, is the cohesion and internal friction angle of the soil layer, F and N are the tensile and compressive loads of the pole tower, r 0 is the radius of the soil cavity 8, H is the vertical distance from the top of the soil cavity 8 to the ground surface, L is the horizontal distance from the top of the soil cavity 8 to the center of the bottom of the pole tower foundation 1, L 0 is the horizontal distance from the embedded device 2 to the pole tower foundation 1 when the soil cavity 8 appears directly below the pole tower foundation 1, H 0The depth of the embedded device 2 when the soil cavity 8 appears directly below the tower foundation 1, H 1 The depth of the embedded device 2 at the apex of the soil cavity expansion line 9, L 1 The horizontal distance from the embedded device 2 at the apex of the soil cavity expansion line 9 to the tower foundation 1.

[0066] In this embodiment, for the convenience of construction and without affecting the normal operation of the tower foundation and the monitoring effect, when the soil cavity 8 appears directly below the tower foundation 1, the embedded component 21 is selected to be closely attached to the tower foundation 1 and embedded.

[0067] Embodiment 3:

[0068] The basic content is the same as that of Embodiment 2, the difference lies in:

[0069] In step four, generating the friction force curve graph includes:

[0070] The first monitoring device 3 and the second monitoring device 4 respectively collect the friction force change data at two different positions, namely the middle and the bottom of the calcium oxide powder 7 and the hollow column 211, and transmit them to the control center 6 via wireless signals at a frequency of once per second. The control center 6 forms two visual change curves from the data to form the friction force curve graph.

[0071] In step four, judging whether the calcium oxide powder 7 is exhausted and the expansion situation of the soil cavity 8 includes:

[0072] The control center 6 calculates the slope change of each group of the collected friction force change data in groups of 10 s;

[0073] When the slope change trends of the first curve and the second curve are small floating fluctuations or stationary, it is within the allowable error range. At this time, the soil cavity 8 has no expansion and the calcium oxide powder 7 is not exhausted;

[0074] When the slope change trend of the first curve is first small floating fluctuations or stationary, then increases rapidly, and then slowly decreases to 0, and the change trend of the second curve is the same as that of the first curve, at this time the soil cavity 8 has expanded to the bottom of the hollow column 211 and the calcium oxide powder 7 is about to be exhausted;

[0075] When the slope change trend of the first curve is first small floating fluctuations or stationary, then increases rapidly, and then drops suddenly to 0 and there is no change for a long time; the change trend of the second curve is the same as that of the first curve, at this time the soil cavity 8 has expanded to the bottom of the hollow column 211 and the calcium oxide powder 7 has been exhausted.

[0076] In this embodiment, when the slope difference between adjacent sets of data in two curves is more than double, the control center 6 will issue a warning notice. The staff needs to focus on the curve change trend of the warning group to determine whether the calcium oxide powder 7 is exhausted and make corresponding preparations. If there are small fluctuations in the first curve within 30 minutes after it decreases, it indicates that the consumption of the calcium oxide powder 7 is less than half at this time; if the first curve drops suddenly to 0 when decreasing and there is no change within 30 minutes, it indicates that the consumption of the calcium oxide powder 7 is more than half.

[0077] Example 4:

[0078] The basic content is the same as that of Example 3, and the differences are as follows:

[0079] In step five, the treatment for filling the soil cave 8 includes:

[0080] When the soil cave 8 expands to the bottom of the hollow column 211 and the calcium oxide powder 7 is about to be exhausted, fill the calcium oxide powder 7 into the hollow column 211 until the calcium oxide powder 7 is flush with the upper end face of the hollow column 211;

[0081] When the soil cave 8 expands to the bottom of the hollow column 211 and the calcium oxide powder 7 has been exhausted, find the corresponding hollow column 211, inject water into the hollow column 211, and at the same time detect the heat in the soil cave 8 through the third monitoring device 5 and determine the shape of the soil cave 8. The control center 6 determines that the filling material for the soil cave 8 is a silicate material according to the shape of the soil cave 8, then inserts a perfusion pipe into the hollow column 211, and flows the silicate material into the soil cave 8 through the perfusion pipe. At this time, a large amount of calcium hydroxide is generated by the chemical reaction of the calcium oxide powder 7 and water in the soil cave 8 and reacts with the added silicate material to generate calcium silicate gel to fill the soil cave 8.

[0082] In this embodiment, the silicate material can be industrial by-products such as fly ash and slag powder. When the fly ash and slag powder flow into the soil cave 8, a large amount of calcium hydroxide is generated by the chemical reaction of the calcium oxide powder 7 and water in the soil cave 8 and reacts with the active silicon and aluminum components of the fly ash and slag powder to generate calcium silicate - calcium aluminate gel (C - S - H). And at this time, the temperature in the soil cave 8 is relatively high, and the calcium silicate - calcium aluminate gel (C - S - H) has high strength and low permeability, and the filling effect is good.

Claims

1. A monitoring and filling device for the expansion of karst soil caves around transmission towers, characterized in that: The invention comprises a control center (6) and a plurality of embedded devices (2), wherein the plurality of embedded devices (2) are coaxially arranged on the outside of a pole tower foundation (1) with the pole tower as the center, and the plurality of embedded devices (2) are all installed in a karst soil body, the embedded devices (2) comprise a plurality of embedded components (21), and the plurality of embedded components (21) surround the outside of the pole tower in a circumferential direction, and the embedded components (21) comprise a hollow column (211), a first monitoring device (3), a second monitoring device (4), and a third monitoring device (5), the hollow column (211) is installed in the karst soil body and filled with calcium oxide powder (7), the first monitoring device (3) and the second monitoring device (4) are sequentially installed on the inner side wall of the hollow column (211), the third monitoring device (5) is movably installed in the hollow column (211), and the first monitoring device (3), the second monitoring device (4), and the third monitoring device (5) are all connected to the control center (6); The first monitoring device (3) and the second monitoring device (4) are used to respectively detect the friction force when the calcium oxide powder (7) flows in the hollow column (211), and transmit the friction force to the control center (6); The third monitoring device (5) is used to monitor the heat generated after the calcium oxide powder (7) reacts with water to determine the shape of the soil hole (8); The control center (6) is used to determine whether the calcium oxide powder (7) is exhausted and the expansion of the soil hole (8) based on the friction force, and to determine the material required to fill the soil hole (8) in combination with the shape of the soil hole (8) monitored by the third monitoring device (5).

2. A monitoring and filling device for expansion of karst soil caves around transmission towers according to claim 1, characterized in that: The hollow column (211) is provided with a first mounting hole (212) and a second mounting hole (213); the first mounting hole (212) is provided with a first hollow tube (214); the second mounting hole (213) is provided with a second hollow tube (215); the third monitoring device (5) is movably connected to the first hollow tube (214); the first monitoring device (3) and the second monitoring device (4) are respectively installed on the inner side wall of the second hollow tube (215); the calcium oxide powder (7) is filled in the second hollow tube (215); the outer peripheral surface of the hollow column (211) is connected with a plurality of steel bars (216); the plurality of steel bars (216) are all arranged in the karst soil.

3. The monitoring and filling device for the expansion of karst soil caves around transmission towers according to claim 2 is characterized in that: The third monitoring device (5) comprises a telescopic long rod (51) and an infrared thermal imaging camera (52), wherein the telescopic long rod (51) is arranged in the first hollow tube (214), and the infrared thermal imaging camera (52) is installed at the bottom of the telescopic long rod (51).

4. The monitoring and filling device for expansion of karst soil caves around transmission towers according to claim 2 is characterized in that: The first monitoring device (3) includes a first friction sensor (31), and the second monitoring device (4) includes a second friction sensor (41). The first friction sensor (31) is installed at the middle of the inner wall of the second hollow tube (215), and the second friction sensor (41) is installed at the bottom of the inner wall of the second hollow tube (215).

5. A method for monitoring and filling the expansion of karst soil caves around transmission towers, characterized in that: The monitoring and filling method is applied to the monitoring and filling device for the expansion of karst soil caves around transmission towers according to claim 1, and the monitoring and filling method comprises the following steps: Step 1: Select a pole tower to be monitored, detect a soil hole (8) below the pole tower, and determine the positions of a plurality of pre-buried devices (2) according to the position and size of the soil hole (8); Step 2: digging a pit at the determined position according to the depth of each embedded component (21), and placing the multiple embedded components (21) in each embedded device (2) into the processed deep pit along the circumferential direction with the tower as the center; Step 3: installing the first monitoring device (3), the second monitoring device (4), and the third monitoring device (5) in the hollow column (211), and simultaneously filling the hollow column (211) with calcium oxide powder (7), so that the calcium oxide powder (7) is in contact with the karst soil; Step 4: The friction between the calcium oxide powder (7) and the hollow column (211) is monitored by the first monitoring device (3) and the second monitoring device (4), and the control center (6) generates a friction curve diagram based on the acquired friction data, and determines whether the calcium oxide powder (7) is exhausted and the expansion of the soil hole (8); Step 5: The control center (6) fills the soil hole (8) according to whether the calcium oxide powder (7) is exhausted and the expansion of the soil hole (8), combined with the shape of the soil hole (8) monitored by the third monitoring device (5).

6. A method for monitoring and filling expansion of karst soil caves around transmission towers according to claim 5, characterized in that: The number of the embedded devices (2) is four, and the four embedded devices (2) are arranged in a staggered manner in a ring with the pole tower as the center. The specific steps of determining the positions of the plurality of embedded devices (2) in step 1 are as follows: Numerical simulation is performed using finite element simulation software to obtain the expansion critical line function f of the soil hole (8). The expansion critical line function f is divided into multiple equal parts to determine the positions of the four embedded devices (2). The horizontal distances of the four embedded devices (2) from the tower foundation (1) are L0, L2, L3, and L1, respectively. The depths of the four embedded devices (2) are H0, H2, H3, and H1, respectively. The calculation formula is as follows: f=αr0+βL+λH; Among them, c, are the cohesion and internal friction angle of the soil layer, F and N are the tensile and compressive loads of the pole tower, r0 is the radius of the soil hole (8), H is the vertical distance from the top of the soil hole (8) to the ground surface, L is the horizontal distance from the top of the soil hole (8) to the bottom center of the pole tower foundation (1), L0 is the horizontal distance from the embedded device (2) to the pole tower foundation (1) when the soil hole (8) appears directly below the pole tower foundation (1), H0 is the depth of the embedded device (2) when the soil hole (8) appears directly below the pole tower foundation (1), H1 is the depth of the embedded device (2) located at the arch point of the soil hole expansion line (9), and L1 is the horizontal distance from the embedded device (2) located at the arch point of the soil hole expansion line (9) to the pole tower foundation (1).

7. The method for monitoring and filling the expansion of karst soil caves around transmission towers according to claim 5, characterized in that: The step 4 of generating a friction force curve graph includes: The first monitoring device (3) and the second monitoring device (4) respectively collect friction force variation data between the calcium oxide powder (7) and the hollow column (211) at two different positions, the middle and the bottom, and transmit the data to the control center (6) via wireless signals at a frequency of once per second. The control center (6) forms two visualized variation curves to form a friction force curve graph.

8. The method for monitoring and filling the expansion of karst soil caves around transmission towers according to claim 7, characterized in that: The step 4 of judging whether the calcium oxide powder (7) is exhausted and the expansion of the soil hole (8) includes: The control center (6) calculates the slope change of each group of the collected friction force change data in groups of 10 seconds; When the slope variation trend of the first curve and the second curve is a small floating fluctuation or no change, it is within the allowable error range. At this time, the soil hole (8) has not expanded and the calcium oxide powder (7) has not been exhausted; When the slope of the first curve changes in a trend of first small floating fluctuations or no movement, then rapidly increasing, and then slowly decreasing to 0, the change trend of the second curve is the same as the first curve, at this time the soil hole (8) has expanded to the bottom of the hollow column (211) and the calcium oxide powder (7) is about to be exhausted; When the slope of the first curve changes in a trend of first small floating fluctuations or no movement, then rapidly increasing, then suddenly dropping to 0, and remaining unchanged for a long time; the second curve changes in a trend the same as the first curve, at this time the soil hole (8) has expanded to the bottom of the hollow column (211) and the calcium oxide powder (7) has been exhausted.

9. A method for monitoring and filling expansion of karst soil caves around transmission towers according to claim 8, characterized in that: The step 5 of filling the soil hole (8) comprises: When the soil hole (8) expands to the bottom of the hollow column (211) and the calcium oxide powder (7) is about to be exhausted, the calcium oxide powder (7) is filled into the hollow column (211) until the calcium oxide powder (7) is flush with the upper end surface of the hollow column (211); When the soil hole (8) expands to the bottom of the hollow column (211) and the calcium oxide powder (7) is exhausted, the corresponding hollow column (211) is found and water is injected into the hollow column (211). At the same time, the heat in the soil hole (8) is detected by the third monitoring device (5) and the shape of the soil hole (8) is determined. The control center (6) determines that the filling material of the soil hole (8) is a silicate material according to the shape of the soil hole (8). Then, a perfusion pipe is inserted into the hollow column (211) and the silicate material is flowed into the soil hole (8) through the perfusion pipe. At this time, the calcium oxide powder (7) in the soil hole (8) reacts chemically with water to generate a large amount of calcium hydroxide, which reacts with the added silicate material to generate calcium silicate gel to fill the soil hole (8).

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