Composite foundation and construction method of power transmission tower under earthquake and karst poor geological environment

Abstract

The application discloses a kind of transmission tower composite foundation under earthquake and karst poor geological environment and construction method, foundation includes: foundation unit, it includes filter cloth (6) being arranged in foundation pit, bidirectional reinforcement net (5) being arranged above the filter cloth (6);Composite structure unit is arranged on foundation unit, it includes carbon fiber woven lattice net (1) being arranged on the bidirectional reinforcement net (5), rubber particle mixed soil (4), and monitoring early warning unit, it includes pressure sensor (7) being arranged between the filter cloth (6) and bidirectional reinforcement net (5), transmission tower foundation (14) is equipped with displacement sensor (8).The application is lost by using filter cloth, bidirectional reinforcement net to strengthen the control of underground water and the upgrading of the degree of foundation cementation, by using BFRP pipe and expandable circular arc steel plate strengthens the support to foundation structure, forms a complete set of preventive maintenance system.

Description

Technical Field

[0001] This invention belongs to the field of power transmission line technology, and more specifically, relates to a composite foundation for power transmission towers and a construction method for such foundations in adverse geological environments such as earthquakes and karst formations. Background Technology

[0002] With the development of the national power industry, transmission towers are increasingly being installed in areas with more complex geological structures. my country has a wide range of seismic faults, experiences high seismic intensity, and is prone to frequent earthquakes, resulting in numerous geological disasters and infrastructure damage caused by earthquakes every year. In recent years, the safety and stability of transmission towers under seismic loads has attracted significant attention and concern during the construction of power grid projects.

[0003] Furthermore, transmission towers are inevitably erected in karst areas, which contain sinkholes and cavities that significantly impact the stability of the tower foundations. Improper foundation design and construction can lead to uneven settlement and overall foundation failure, causing the towers to tilt, deform, or even overturn, severely threatening line safety and resulting in direct economic losses of millions of yuan and indirect economic losses of hundreds of millions of yuan. This invention provides a composite foundation and construction method for transmission towers in seismic and karst geological environments, thereby ensuring the safety and stability of transmission towers under seismic action and adverse geological conditions in karst areas, and avoiding unnecessary economic losses. Summary of the Invention

[0004] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a composite foundation and construction method for power transmission towers in adverse geological environments such as earthquakes and karst formations. It utilizes a carbon fiber woven grid filled with rubber-particle mixed soil to reduce the impact of seismic amplitude on the power transmission tower foundation. By using filter cloth and bidirectional steel mesh to enhance groundwater loss control and improve foundation cohesion, it prevents foundation settlement to a certain extent. The use of BFRP pipes and expandable arc-shaped steel plates strengthens the support of the foundation structure, increasing the pressure area against the foundation sides and reducing settlement velocity. Finally, pressure and displacement sensors monitor the data. When abnormal data is detected, an early warning module and a wireless transmission module send information to the control center and then to the terminal module, simultaneously controlling the electric rotor to tighten the tension wires, expanding the arc-shaped steel plate to increase the stress area and delay settlement, thus providing more time for remedial action and forming a complete preventative maintenance system.

[0005] To achieve the above objectives, according to one aspect of the present invention, a composite foundation for power transmission towers in adverse geological environments such as earthquakes and karst formations is provided, comprising:

[0006] The basic unit includes a filter cloth placed in the foundation pit and a bidirectional steel mesh placed above the filter cloth;

[0007] At least one layer of composite structural unit is provided on the basic unit, which includes a carbon fiber woven grid mesh provided on the bidirectional steel mesh, rubber particle mixed soil filled inside the carbon fiber woven grid mesh, the carbon fiber woven grid mesh is provided with reserved holes around its perimeter, BFRP pipes are longitudinally inserted through the reserved holes, and sleeves are used to maintain the stability of the connection structure at the upper and lower connection points of the BFRP pipes, and arc steel plates are horizontally fixedly connected to the outside of each BFRP pipe.

[0008] The system includes a monitoring and early warning unit, comprising a pressure sensor located between the filter cloth and the bidirectional steel mesh for monitoring the pressure distribution of the transmission tower foundation and providing early warning of the development of karst caves. The transmission tower foundation is installed on the carbon fiber woven grid and compacted. Each of the two opposite transmission tower foundations is equipped with a displacement sensor that is interconnected to monitor whether there is any settlement in the horizontal position of the foundation. The pressure sensor and the displacement sensor are connected to the display and early warning device via wires.

[0009] Furthermore, the interior of the carbon fiber woven lattice is honeycomb-shaped, and the honeycomb gaps of the carbon fiber woven lattice are opened by an auxiliary steel sheet inner support frame so that the rubber particle mixed soil can be filled into it.

[0010] Furthermore, the rubber content in the rubber particle mixed soil is greater than or equal to 15%.

[0011] Furthermore, multiple layers of the aforementioned carbon fiber woven lattice are stacked, with the stacking angle being 45°-60°.

[0012] Furthermore, the inner diameter of the BFRP tube is 8mm-15mm.

[0013] Furthermore, the arc-shaped steel plate includes a fixed arc-shaped steel plate and an extended arc-shaped steel plate connected thereto;

[0014] The extended arc steel plate is placed on the upper part of the arc steel plate and can rotate around its center.

[0015] Furthermore, the arc-shaped steel plate includes a traction block and a pull wire;

[0016] The traction block is placed between two extended arc steel plates and can move radially around the arc steel plates;

[0017] One end of the pull wire is connected to the traction block, and the other end is connected to the electric rotor.

[0018] Furthermore, the filter cloth is arranged in multiple layers at a 30° angle.

[0019] Furthermore, the display and warning device includes a display module, a warning module, and a wireless transmission module.

[0020] According to a second aspect of the present invention, a construction method for a composite foundation for a power transmission tower in an adverse geological environment of earthquake and karst is provided, comprising:

[0021] S100: Excavate the foundation of the power transmission tower, lay filter cloth at the bottom of the pit, and set up a two-way steel mesh on top of the filter cloth. Multiple pressure sensors are evenly distributed between the filter cloth and the two-way steel mesh to monitor the pressure distribution of the power transmission tower and its foundation and to quickly warn of whether karst caves are developing.

[0022] S200: A first layer of carbon fiber woven grid is set on a two-way steel mesh, and rubber particle mixed soil is filled into the cavity of the carbon fiber woven grid. At the same time, BFRP pipes are longitudinally inserted into the reserved holes around the carbon fiber woven grid, and sleeves are used to connect the upper and lower parts of the BFRP pipes to maintain structural stability. A circular arc steel plate is set on the outside of each BFRP pipe and fixedly connected to it horizontally.

[0023] S300: Repeat step S according to the load requirements of the transmission tower, and set up the rammed and poured transmission tower foundation on the top carbon fiber woven grid. Displacement sensors connected to each other are installed on the two relative positions of the transmission tower foundation to monitor whether there is any settlement in the horizontal position of the foundation.

[0024] S400: The pressure sensor and displacement sensor transmit the data obtained to the display and early warning device through wires. One end of the guy wire is connected to the electric rotor located at a point on the foundation of the transmission tower to complete the construction of the composite foundation of the transmission tower.

[0025] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0026] 1. The composite foundation of this invention utilizes a carbon fiber woven grid filled with rubber particle mixed soil to reduce the impact of seismic amplitude on the foundation of transmission towers; it strengthens the control of groundwater loss and upgrades the foundation's cohesion by using filter cloth and bidirectional steel mesh, thus preventing foundation settlement to a certain extent; it strengthens the support of the foundation structure by using BFRP pipes and expandable arc steel plates, which expands the pressure area with the foundation side, reducing the settlement rate; and finally, it monitors data through pressure sensors and displacement sensors. When the data is abnormal, the early warning module and wireless transmission module send feedback information to the control center and then to the terminal module, while simultaneously controlling the electric rotor to tighten the pull wire, thereby expanding the arc steel plate to increase the stress area and delay settlement, increasing the time for remediation, thus forming a complete prevention and maintenance system.

[0027] 2. In the composite foundation of the present invention, the carbon fiber woven grid is opened by the steel sheet internal support device to allow the rubber particle mixed soil to fill it. The rubber content in the rubber particle mixed soil is 15%, which improves the seismic resistance of the transmission tower composite foundation and absorbs the energy of seismic wave propagation.

[0028] 3. In the composite foundation of the present invention, the filter cloth is provided in three layers at the bottom of the foundation pit, with each layer arranged at a 30° angle to ensure that the normal rise and fall of the groundwater level is not affected, and also to a certain extent to prevent the loss of fine soil particles in the composite foundation and accelerate the settlement of the foundation.

[0029] 4. In the composite foundation of the present invention, pressure sensors equidistantly distributed on the filter cloth are used to sense the pressure value changes at the bottom of the transmission tower foundation. The equidistant arrangement allows for more uniform measurement of the pressure received by the transmission tower at the bottom of the foundation pit. The degree of change in the original pressure value can reflect the void situation in the lower part of the composite foundation, thereby inferring the location and size of the karst cave development.

[0030] 5. In the composite foundation of the present invention, displacement sensors are connected to each other at the foundations of the two transmission towers in opposite positions to monitor whether there is any settlement in the horizontal position of the foundation; and several pressure sensors are evenly distributed on the filter cloth of the composite foundation base to monitor the pressure distribution of the transmission towers and the transmission tower foundations on them, so as to quickly warn of whether there is karst cave development.

[0031] 6. In the method of the present invention, when the end of the pull wire connected to the electric rotor is tightened, the pull wire is driven to cause the traction block to move radially around the arc steel plate to reach the center, thereby moving the two extended arc steel plates in opposite directions around the center, so that the arc steel plates change from the initial state to the extended state, making the contact area between the arc steel plates and the side of the foundation and the horizontal force-bearing area larger, thereby reducing the settlement rate of the foundation and buying more time for remediation.

[0032] 7. In the method of the present invention, if an abnormal data alert occurs, the warning module will transmit the instruction to the wireless transmission module. The wireless transmission module will simultaneously send remedial repair information to the control center and issue a control signal to drive the electric rotor to rotate the pull wire, causing the arc steel plate to expand and slow down the foundation settlement rate. The control center will locate the transmission tower to which the signal was sent based on the alarm signal and send the tower number and coordinate information to the terminal module assigned by the control center. This allows the rescue signal to be transmitted to the distance-priority terminal more quickly and accurately, realizing early warning of tower foundation deformation. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a carbon fiber woven lattice structure in a composite foundation for a power transmission tower under adverse geological conditions such as earthquakes and karst.

[0034] Figure 2 This is a schematic diagram of a composite foundation for a power transmission tower under adverse geological conditions of earthquake and karst, according to an embodiment of the present invention.

[0035] Figure 3 This is a cross-sectional view of a composite foundation for a power transmission tower under adverse geological conditions of earthquake and karst, according to an embodiment of the present invention.

[0036] Figure 4 This is a schematic diagram of the planar arrangement of the pressure sensor according to an embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of the initial state of the arc-shaped steel plate according to an embodiment of the present invention;

[0038] Figure 6 This is a schematic planar view of the extended state of the arc-shaped steel plate according to an embodiment of the present invention;

[0039] Figure 7 This is a schematic diagram of the early warning signal transmission according to an embodiment of the present invention;

[0040] Figure 8 This is a line graph comparing the inclination of the transmission tower foundation according to an embodiment of the present invention;

[0041] Figure 9 This is a line graph comparing the average heave of the foundation in an embodiment of the present invention.

[0042] Figure 10 This is a line graph comparing the settlement of the transmission tower foundation according to an embodiment of the present invention.

[0043] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1-carbon fiber woven lattice mesh, 2-BFRP pipe, 3-arc steel plate, 4-rubber granule mixed soil, 5-bidirectional steel mesh, 6-filter cloth, 7-pressure sensor, 8-displacement sensor, 9-display and early warning device, 10-reserved hole, 11-sleeve, 12-conductor, 13-electric rotor, 14-transmission tower foundation, 301-fixed arc steel plate, 302-expanded arc steel plate, 303-traction block, 304-guerre wire. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0045] like Figure 1 , 2As shown in Figures 3 and 4, this embodiment of the invention provides a composite foundation for transmission towers in adverse geological environments such as earthquakes and karst formations. The foundation includes: a filter cloth 6 laid at the bottom of the foundation pit; a bidirectional steel mesh 5 placed above the filter cloth 6; pressure sensors 7 laid at equal intervals between the two; a carbon fiber woven grid 1 placed on the bidirectional steel mesh 5; rubber particle mixed soil 4 filled inside the carbon fiber woven grid 1; pre-drilled holes 10 around the carbon fiber woven grid 1; BFRP pipes 2 that can be longitudinally inserted through the pre-drilled holes 10; sleeves 11 that maintain structural stability at the upper and lower connections of the BFRP pipes 2; and arc-shaped steel plates 3 that can be horizontally fixed to the outside of each BFRP pipe 2. The system of this invention utilizes a carbon fiber woven grid filled with rubber particle mixed soil to reduce the impact of seismic amplitude on the foundation of transmission towers; it strengthens the control of groundwater loss and upgrades the foundation cohesion by using filter cloth and bidirectional steel mesh, thus preventing foundation settlement to a certain extent; and it strengthens the support of the foundation structure by using BFRP pipes and expandable arc steel plates, which expandably increases the pressure area with the side of the foundation and reduces the settlement rate.

[0046] The carbon fiber woven grid 1 has a honeycomb structure inside, with overall dimensions of 2000mm*2000mm*300mm. The carbon fiber structure is 3mm thick. The carbon fiber woven grid 1 is opened up by an auxiliary steel sheet internal support to allow the rubber particle mixed soil 4 to be filled. The rubber content in the rubber particle mixed soil is greater than or equal to 15%, which helps to improve the seismic resistance of the transmission tower composite foundation and absorb the energy of seismic wave propagation. Then, BFRP pipes 2 with an inner diameter of 8mm-15mm are vertically inserted into the reserved holes 10 at the four corners of the carbon fiber woven grid 1, and the auxiliary steel sheet support is removed for compaction. The arc-shaped steel plate 3 is horizontally fixed to the outside of the BFRP pipe 2. This operation is repeated to stack the carbon fiber woven grid 1, with the stacking angle being 45°-60°. The filter cloth 6 has three layers at the bottom of the foundation pit, each layer arranged at a 30° angle to ensure that the normal rise and fall of the groundwater level is not affected, and also to a certain extent to prevent the loss of fine soil particles in the composite foundation and accelerate the settlement of the foundation. The pressure sensors 7, which are equally distributed on the filter cloth 6, are used to sense the pressure value changes at the bottom of the transmission tower foundation. The equally distributed arrangement allows for more uniform measurement of the pressure exerted by the transmission tower on the bottom of the foundation pit. The degree of change in the original pressure value can reflect the voids in the lower part of the composite foundation, thereby inferring the location and size of the karst soil cavities.

[0047] like Figure 3 , 5As shown in Figure 6, this embodiment of the invention provides a composite foundation for transmission towers in adverse geological environments such as earthquakes and karst formations. The arc-shaped steel plate 3, horizontally fixed and connected to the outside of the BFRP pipe 2, is an expandable steel plate. The arc-shaped steel plate 3 is composed of a fixed arc-shaped steel plate 301, two expandable arc-shaped steel plates 302, a traction block 303, and a guy wire 304. The two expandable arc-shaped steel plates 302 are positioned on the upper part of the arc-shaped steel plate 3 and can rotate around its center. The traction block 303 is positioned between the two expandable arc-shaped steel plates 302 and can move radially around the arc-shaped steel plate 3. One end of the guy wire 304 is connected to the traction block 303, and the other end is connected to an electric rotor 13 installed at the location of the transmission tower foundation. When the end of the pull wire 304 connected to the electric rotor 13 is tightened, the pull wire 304 is driven to move the traction block 303 radially around the arc steel plate 3 to the center, thereby moving the two extended arc steel plates 302 in opposite directions around the center, so that the arc steel plate 3 changes from the initial state to the extended state, making the contact area between the arc steel plate 3 and the side of the foundation and the horizontal force area larger, thereby reducing the settlement speed of the foundation and buying some time for remediation.

[0048] like Figure 3 , 7 As shown in this embodiment of the invention, a compacted and cast-in-place transmission tower foundation 14 is provided on the composite foundation of the transmission tower. Displacement sensors 8 are interconnected at two opposite positions on the transmission tower foundation 14 to monitor whether horizontal settlement has occurred in the foundation. Several pressure sensors 7 are evenly distributed on the filter cloth 6 of the composite foundation base, which can be used to monitor the pressure distribution on the transmission tower and its foundation to quickly warn of the development of karst caves. The two sensors transmit the obtained data to the display and warning device 9 via wires 12. Since the pressure sensors 7 are located at the composite foundation base, which is far from the display and warning device 9 on the horizontal surface, and to prevent data transmission from being affected by karst caves in the foundation, the wires 12 used for data transmission are housed in BFRP pipes 2. This type of fiber composite pipe has a stable structure, high strength, and corrosion resistance, allowing the wires 12 to transmit data stably without interference. Furthermore, a horizontally fixed arc-shaped steel plate 3 is provided on the outside of the BFRP pipe 2, and one end of the guy wire 304 is connected to an electric rotor 13 located at the foundation 14 of the transmission tower. The system of this invention monitors data through pressure sensors and displacement sensors. When the data is abnormal, the early warning module and the wireless transmission module send feedback information to the control center and then to the terminal module. Simultaneously, the system controls the electric rotor to tighten the guy wire, expanding the arc-shaped steel plate to increase the stress area and delay settlement, thus providing more time for remedial action and forming a complete preventative maintenance system.

[0049] When a value of pressure sensor 7 is 0 or the value of displacement sensor 8 changes, it indicates that the composite foundation of the transmission tower has karst caves, leading to changes in pressure distribution and settlement of the transmission tower, respectively. The conductor 12 transmits the data to the display and early warning device 9, which includes a display module, an early warning module, and a wireless transmission module. When the data is transmitted to the device 9, the information data is first displayed on the display module. If an abnormal data alert occurs, the command will be transmitted to the wireless transmission module through the early warning module. The wireless transmission module simultaneously sends remedial repair information to the control center and sends a control signal to drive the electric rotor 13 to rotate the pull wire 304, causing the arc steel plate 3 to expand and slow down the settlement rate of the foundation. The control center locates the transmission tower that received the signal based on the alarm signal and sends the tower's number and coordinate information to the terminal module assigned by the control center, so that the rescue signal can be transmitted to the distance-priority terminal more quickly and accurately.

[0050] In another embodiment of the present invention, a method for constructing a composite foundation for transmission towers in adverse geological environments such as earthquakes and karst is provided, comprising:

[0051] S100: Excavate the foundation of the power transmission tower, lay filter cloth 6 at the bottom of the pit, and set up a two-way steel mesh 5 above the filter cloth 6. Multiple pressure sensors 7 are evenly distributed between the filter cloth 6 and the two-way steel mesh 5 to monitor the pressure distribution of the power transmission tower and its foundation and to quickly warn of whether karst caves are developing.

[0052] S200: A first layer of carbon fiber woven grid 1 is set on the bidirectional steel mesh 5, and rubber particle mixed soil 4 is filled in the cavity of the carbon fiber woven grid 1. At the same time, BFRP pipes 2 are longitudinally inserted into the reserved holes 10 around the carbon fiber woven grid 1, and sleeves 11 are used to connect the upper and lower parts of the BFRP pipes 2 to maintain structural stability. A circular arc steel plate 3 is set on the outside of each BFRP pipe 2 and fixedly connected to it horizontally.

[0053] S300: Repeat step S200 according to the load requirements of the transmission tower, and set up a rammed and poured transmission tower foundation 14 on the top carbon fiber woven grid 1. Displacement sensors 8 are connected to each other at the two relative positions of the transmission tower foundation 14 to monitor whether there is any settlement in the horizontal position of the foundation.

[0054] S400: The pressure sensor 7 and displacement sensor 8 transmit the obtained data to the display and early warning device 9 through the wire 12. One end of the pull wire 304 is connected to the electric rotor 13 located at the foundation 14 of the transmission tower to complete the construction of the composite foundation of the transmission tower.

[0055] like Figure 8 , 9As shown in Figure 10, in another embodiment of the invention, according to the line graph comparing the amplitude-to-transmission tower foundation inclination, amplitude-to-average foundation uplift value, and karst soil cavity diameter-to-transmission tower foundation settlement with respect to the traditional construction method and the construction method of the embodiment of the present invention, it can be seen that the carbon fiber woven grid 1 and the filled rubber particle mixed soil 4 of the present invention effectively reduce the influence of amplitude on the transmission tower foundation after multiple 45° superpositions, reducing the inclination and settlement. The BFRP pipe 2 used in the composite foundation is a fiber composite material combined with an expandable arc steel plate 3, which can expand outward when settlement occurs, i.e., when the displacement sensor value changes, increasing the force-bearing area with the side of the foundation, thereby reducing the settlement rate and preventing settlement. The filter cloth 6 at the bottom of the composite foundation pit is set in three layers at a 30° cross-overlay, which effectively prevents excessive loss of groundwater and also ensures the retention of some fine soil particles; while the bidirectional steel mesh on it is made of epoxy resin, which can accelerate the reinforcement of the composite foundation and provide strong support upward. Furthermore, due to its corrosion resistance, high strength and low shrinkage, it can also prevent the development and expansion of karst soil cavities, and limit its settlement deformation and collapse to a certain extent.

[0056] The purpose of this invention is to address the issue of power transmission tower foundations inevitably located in earthquake zones and karst areas. It utilizes a carbon fiber woven mesh filled with rubber-particle mixed soil to reduce the impact of seismic amplitude on the tower foundation. By using filter cloth and bidirectional steel mesh to enhance groundwater control and improve foundation cohesion, it prevents foundation settlement to some extent. The use of BFRP pipes and expandable arc-shaped steel plates strengthens the support of the foundation structure, increasing the pressure area against the foundation sides and reducing settlement velocity. Finally, pressure and displacement sensors monitor data; when abnormal data is detected, an early warning module and a wireless transmission module send information to the control center and then to the terminal module. Simultaneously, the electric rotor tightens the tension wires, expanding the arc-shaped steel plate to increase the stress area and delay settlement, thus providing more time for remedial action. This forms a complete preventative maintenance system.

[0057] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A composite foundation for a power transmission tower in a seismic and karst poor geological environment, characterized in that, It comprises: a foundation unit comprising a filter cloth (6) arranged in a foundation pit, and a two-way steel mesh (5) arranged above the filter cloth (6); at least one layer of composite structure unit arranged on the foundation unit, comprising a carbon fiber woven lattice net (1) arranged on the two-way steel mesh (5), and rubber particle mixed soil (4) filled in the carbon fiber woven lattice net (1), the carbon fiber woven lattice net (1) being provided with a reserved hole (10), a BFRP pipe (2) longitudinally implanted through the reserved hole (10), a sleeve (11) connected at the upper and lower parts of the BFRP pipe (2) for maintaining the stability of the connecting structure, and a circular arc steel plate (3) horizontally fixedly connected to the outer side of each BFRP pipe (2); the circular arc steel plate (3) comprises a fixed circular arc steel plate (301) and an extended circular arc steel plate (302) connected thereto; the extended circular arc steel plate (302) is arranged on the upper part of the circular arc steel plate (3) and can rotate around the center of the circular arc steel plate (3); the circular arc steel plate (3) further comprises a traction block (303) and a pull wire (304); the traction block (303) is arranged between the two extended circular arc steel plates (302) and can move radially around the circular arc steel plate (3); one end of the pull wire (304) is connected to the traction block (303), and the other end is connected to an electric rotor (13); and a monitoring and early warning unit comprising a pressure sensor (7) arranged between the filter cloth (6) and the two-way steel mesh (5) for monitoring the pressure distribution of the power transmission tower foundation and quickly warning the development state of karst soil cave; a rammed and poured power transmission tower foundation (14) is arranged on the carbon fiber woven lattice net (1); two opposite power transmission tower foundations (14) are each provided with a displacement sensor (8) connected to each other for monitoring whether the horizontal position of the foundation has a settlement phenomenon; the pressure sensor (7) and the displacement sensor (8) are in communication connection with a display and warning device (9) through a wire (12).

2. The composite foundation of a power transmission tower in a seismic and karst unfavorable geological environment according to claim 1, characterized in that, The inside of the carbon fiber woven lattice net (1) is honeycomb-shaped, and the honeycomb gaps of the carbon fiber woven lattice net (1) are expanded by an auxiliary device steel sheet inner support frame so as to fill the rubber particle mixed soil (4) therein.

3. The composite foundation of a power transmission tower in a seismic and karst unfavorable geological environment according to claim 2, characterized in that, The proportion of rubber in the rubber particle mixed soil (4) is greater than or equal to 15%.

4. The composite foundation of a power transmission tower in a seismic and karst unfavorable geological environment according to claim 3, characterized in that, Multiple layers of the carbon fiber woven lattice net (1) are stacked, and the stacking angle is 45°-60°.

5. The composite foundation of a power transmission tower in a seismic and karst unfavorable geological environment according to claim 4, characterized in that, The inner diameter of the BFRP pipe (2) is 8mm-15mm.

6. The composite foundation of a power transmission tower in a seismic and karst unfavorable geological environment according to any one of claims 1-5, characterized in that, The filter cloth (6) is arranged by multiple layers of cross-stacking at an angle of 30°.

7. The composite foundation of a power transmission tower in a seismic and karst unfavorable geological environment according to any one of claims 1-5, characterized in that, The display and warning device (9) comprises a display module, a warning module and a wireless transmission module.

8. The construction method of the composite foundation of the power transmission tower under the seismic and karst unfavorable geological environment according to any one of claims 1-7, characterized in that, It comprises: S100: excavating and processing the power transmission tower foundation, laying a filter cloth (6) at the bottom of the foundation pit, arranging a two-way steel mesh (5) above the filter cloth (6), and uniformly arranging multiple pressure sensors (7) between the filter cloth (6) and the two-way steel mesh (5) for monitoring the pressure distribution of the power transmission tower and the power transmission tower foundation and quickly warning whether karst soil cave is developing; S200: Set the first layer of carbon fiber woven lattice network (1) on the bidirectional steel mesh (5), and fill the rubber particle mixed soil (4) in the cavity of the carbon fiber woven lattice network (1), at the same time, longitudinally implant the BFRP pipe (2) in the reserved hole (10) around the carbon fiber woven lattice network (1), and connect the sleeve (11) at the upper and lower connecting parts of the BFRP pipe (2) to keep the structure stable, and set the circular arc steel plate (3) horizontally fixedly connected with the BFRP pipe (2) outside each BFRP pipe (2); S300: Repeat step S200 according to the load demand of the power transmission tower pole, and set the rammed and poured power transmission tower foundation (14) on the top layer of carbon fiber woven lattice network (1), and the displacement sensor (8) connected with each other is arranged at two opposite positions of the power transmission tower foundation (14) for monitoring whether the horizontal position of the foundation has the settlement phenomenon; S400: The pressure sensor (7) and the displacement sensor (8) transmit the obtained data to the display and early warning device (9) through the wire (12), one end of the pull wire (304) is connected with the electric rotor (13) arranged at the power transmission tower foundation (14), and the construction of the composite foundation of the power transmission tower pole is completed.

Images