CN-121976559-A - Lightning current impulse resistant conductive concrete pole tower foundation and construction method thereof

Abstract

The invention relates to the technical field of power system transmission line grounding engineering. A lightning current impulse resistant conductive concrete pole tower foundation is characterized by comprising a multi-component collaborative modified conductive concrete layered gradient formula system, a conductive-enhancement-anti-aging collaborative optimized layered formula, a lightning current multi-path directional dispersion and gradient buffering integrated structure, a gradient buffering anti-cracking structure, a damage full life cycle intelligent management and control system, a multi-dimensional perception network, an active intervention and self-repairing mechanism, an extreme environment adaptation strengthening structure, an anti-freezing expansion strengthening structure, a coastal high salt fog area anti-corrosion strengthening structure and a strong earthquake area anti-shearing and anti-shock strengthening structure. The lightning current directional distribution, the thermal stress accurate buffering, the damage real-time management and control and the extreme environment adaptation are realized, and the impact resistance and the service reliability of the foundation are greatly improved.

Inventors

• YANG CHUYUAN
• Tao Yinyu
• LIU SHIBIN
• LU YUN
• LI XIANSHAN
• LI XINYAN
• GAN YAN
• WANG FENG
• FANG WEN
• LI FEI
• XIE LIHUI
• CHEN BIN
• WANG XUWEI
• WANG MIN
• LUO CHAO
• XIANG CHUAN
• XIE QIONGYAO
• XIANG KUN
• YANG LINGXI
• Zhu tianan
• XIANG YING
• HE QI
• LI HUANGQIANG
• WANG MENG
• Duan Junge
• LI HAO
• XIA JUNRONG
• WANG LEI
• SONG LEI
• YAO JUNWEI
• FAN LIPING
• DENG LING
• Ding Haotao

Assignees

• 国网湖北省电力有限公司宜昌供电公司
• 宜昌长江三峡岸电技术有限公司
• 三峡大学

Dates

Publication Date

20260505

Application Date

20260126

Claims (7)

1. 1. An electrically conductive concrete pole foundation resistant to lightning current surge, comprising: 1) Multi-component synergistic modified conductive concrete layered gradient formula system Based on the functional positioning of different areas of the foundation, a layered formula of 'conduction-enhancement-aging resistance' collaborative optimization is designed, and the components and the functions of each area are as follows: the core pressure-bearing flow-dispersing area takes ordinary Portland cement as a matrix, and the mass percentage of the ordinary Portland cement to the mass of the ordinary Portland cement is 2.5 percent of copper-plated steel fiber, 0.08 percent of graphene oxide and 1.8 percent of expanded graphite are mixed, and 0.4 percent of hindered phenol antioxidant and 0.3 percent of gamma-aminopropyl triethoxy silane coupling agent are added; the secondary flow dispersing buffer area adopts ordinary silicate cement, wherein the mass percentage of the secondary flow dispersing buffer area is 1.8 percent of 316L stainless steel fiber, 15 percent of crystalline flake graphite, 3 percent of metakaolin and 0.3 percent of phosphite antioxidant are mixed with the mass percentage of the ordinary silicate cement; The stable supporting area takes ordinary Portland cement as a matrix, and the following percentages are 1.2% of ordinary steel fiber, 12% of natural graphite and 15% of fly ash relative to the mass of the ordinary Portland cement; 2) Lightning current multipath directional flow dispersion and gradient buffering integrated structure (1) Three-stage flow dispersion guiding system Primary dispersion, namely arranging a titanium alloy skeleton-conductive concrete composite dispersion cap at the top of a main column, wherein the dispersion cap is hemispherical, the inner titanium alloy skeleton adopts a hollowed-out net structure, a 50 mu m thick graphene conductive coating is sprayed on the surface, and lightning current is rapidly dispersed to the whole domain of the main column through the skeleton after being injected, so that single-point current concentration is avoided; The second-level current dispersion is that an annular copper current dispersion pipe network is embedded in the step, the pipe network and the main ribs are fixed through the conductive clamp, and the current conducted by the main column is split to the bottom plate; Three-stage diffusion, namely arranging mutually staggered strip-shaped graphite diffusion strips in the bottom plate along the diagonal direction, wherein the diffusion strips are communicated with an annular pipe network in a welding way to form a three-dimensional diffusion network, so that current is accelerated to flow to soil; (2) Gradient buffering crack-resistant structure The elastic transition layer is arranged at the joint of the main column and the step, and is made of polyurethane-conductive concrete composite material with the thickness of 100mm, the surface of the main rib is made of an epoxy resin-graphite composite coating, and is sleeved with a corrugated ceramic buffer tube, and the edge of the bottom plate is provided with an annular stress release groove; 3) Intelligent management and control system for full life cycle of damage (1) Multidimensional aware network: The temperature-strain collaborative monitoring is that distributed FBG fiber bragg grating sensors are embedded below a main column flow dispersing cap, at two ends of a step main rib and at the intersection of a bottom plate flow dispersing strip, the sensors are distributed in an S shape, each 100mm is provided with a monitoring point, and temperature field and strain field data after lightning current impact are collected in real time; Resistance distribution monitoring, namely embedding miniature soil resistance sensors in different areas of a foundation, and reflecting the integrity of a diffusion channel through resistance change; Transmitting sensor data to an edge computing gateway through a wireless LoRa module, preprocessing the data by the gateway, and uploading the preprocessed data to a remote monitoring platform; (2) Active intervention and self-healing mechanism A) The intelligent grounding resistance adjustment comprises the steps that 12 telescopic conductive graphite electrodes are uniformly arranged at the bottom of a bottom plate and driven by a stepping motor, and a platform automatically adjusts the extending length of the electrodes according to resistance sensor data to dynamically optimize the grounding resistance; b) Multistage self-repair system: Mixing urea formaldehyde resin microcapsule with diameter of 80-150 μm into conductive concrete, and internally packaging epoxy resin-imidazole curing agent with mass ratio of 10:1, wherein the microcapsule breaks when crack is generated, and the curing agent and the epoxy resin polymerize at the crack to realize the repair of microcracks of 0.1-0.3mm within 24 hours; Macroscopic self-repairing, in which a high-pressure grouting pipe is pre-buried in a main column, when a strain sensor detects that the crack width is more than 0.3mm, a platform starts a grouting pump, conductive repair slurry is injected into a crack area, and the resistivity of the repaired area is less than or equal to 3.0 The recovery rate of compressive strength is more than or equal to 90 percent; 4) Extreme environment adaptation strengthening structure (1) Frost heaving prevention reinforcement in high and cold frozen soil areas The composite anti-freezing layer of conductive concrete-extruded sheet-foaming polyurethane is arranged below the bottom plate, the lower layer is a 150mm thick extruded sheet, the middle layer is 100mm thick conductive concrete, the conductive concrete is doped with calcium chloride snow-melting agent with the mass accounting for 5% of the mass of the conductive concrete, the upper layer is 50mm thick foaming polyurethane, the surface of the foundation is coated with 15mm thick conductive heat-insulating paint, heat insulation and dispersion performance are both taken into consideration, and the fluctuation of the grounding resistance in the environment of minus 40 ℃ is ensured to be less than or equal to 3%; (2) Corrosion protection reinforcement for coastal high salt fog area All steel fibers are replaced by marine duplex stainless steel fibers, and the main reinforcement is subjected to double corrosion prevention treatment by hot galvanizing and epoxy coating, wherein the surface of the foundation is coated with a polyurea-graphite composite corrosion prevention coating with the thickness of 3mm, the adhesive force of the coating is more than or equal to 6MPa, and the conductive property attenuation after salt spray aging resistance for 1000 hours is less than or equal to 5%; (3) Shear-resistant and shock-resistant reinforcement in strong earthquake area The joint of the main column and the step is provided with a steel skeleton-conductive concrete combined shear key, the steel skeleton is made of Q460 high-strength steel and is embedded into the main column to a depth of 400mm and is fixed by an embedded anchor bolt, the bottom plate is made of a reinforcing structure of a reinforcing mesh-conductive concrete, the reinforcing mesh is arranged in a double-layer bidirectional manner, and an anti-seismic damper is arranged at the edge of the bottom plate to absorb seismic energy and reduce vibration damage of a foundation.
2. 2. The lightning current surge resistant conductive concrete pole foundation according to claim 1, wherein in the step 1), a core pressure-bearing flow dispersing area comprises copper-plated steel fibers with the diameter of 0.2-0.3mm and the length of 12-15mm, graphene oxide sheets with the thickness of 1-5nm and expanded graphite with the particle size of 50-100 μm; the secondary diffusion buffer zone is 316L stainless steel fiber with diameter of 0.4-0.5mm, length of 20-25mm and particle size of 20-50 μm.
3. 3. The lightning current impact resistant conductive concrete pole tower foundation is characterized in that in the step 2), a primary dispersion is formed by arranging staggered strip-shaped graphite dispersion strips with the cross section of 10mm multiplied by 20mm in the diagonal direction in a base plate, wherein the dispersion cap is hemispherical and has the radius of 300mm, the inner titanium alloy skeleton is of a hollowed-out net structure, the aperture of the hollowed-out net structure is 10mm multiplied by 10mm, the diameter of a pipe is 20mm, the thickness of the pipe wall is 2mm, the pipe network and a main rib are fixed through a conductive clamp, the contact resistance is less than or equal to 0.01 ohm; the composite material is made of polyurethane-conductive concrete, the mass content of the polyurethane is 30%, the thickness is 100mm, the surface of a main rib is an epoxy resin-graphite composite coating, the thickness is 1mm, corrugated ceramic buffer tubes are sleeved, the wall thickness is 3mm, the corrugated interval is 10mm, annular stress relief grooves are formed in the edge of a bottom plate, and the width is 50mm, and the depth is 80mm.
4. 4. The lightning current surge resistant conductive concrete pole foundation according to claim 1, wherein in the step 3), a distributed FBG fiber grating sensor is embedded, the measurement accuracy is that the temperature is +/-0.1 ℃ and the strain is +/-1 mu epsilon, miniature soil resistance sensors are embedded in different areas of the foundation, and the measurement range is 0-10 Precision + -0.01 The sensor data is transmitted by a wireless LoRa module, the transmission distance is more than or equal to 1km, 12 telescopic conductive graphite electrodes are uniformly arranged at the bottom of a bottom plate, the diameter is 40mm, the maximum extension length is 500mm, the grounding resistance is dynamically optimized, the target value is less than or equal to 0.3 omega, a high-pressure grouting pipe is pre-buried in a main column, the pipe diameter is 15mm, and conductive repair slurry is filled into a crack area and is graphite powder, epoxy resin and curing agent, wherein the mass ratio is 3:5:2.
5. 5. The lightning current surge-resistant conductive concrete pole foundation of claim 1, wherein in step 4), the lower layer is a 150mm thick extruded sheet, and the heat conductivity coefficient is less than or equal to 0.028 The upper layer is 50mm thick foaming polyurethane, the closed pore rate is more than or equal to 90%, and the base surface is coated with 15mm thick conductive heat insulation paint which comprises graphite powder, acrylic ester emulsion and hollow glass beads, wherein the mass ratio is 2:6:2; All steel fibers are replaced by marine duplex stainless steel fibers, the salt spray corrosion resistance grade is more than or equal to 2000 hours, the main reinforcement is subjected to double corrosion prevention treatment by hot galvanizing and epoxy coating, the thickness of the coating is more than or equal to 200 mu m, the base surface is coated with a polyurea-graphite composite corrosion prevention coating with the thickness of 3mm, and the mass ratio of polyurea to graphite is=7:3; The steel skeleton is made of Q460 high-strength steel, the cross section is 150mm multiplied by 150mm, the diameter of the embedded anchor bolts is 20mm, the distance is 100mm, the reinforcing steel bar net is arranged in a double-layer bidirectional manner, the diameter is 16mm, and the distance is 150mm.
6. 6. The construction method for realizing the lightning current surge-resistant conductive concrete pole foundation according to claim 1 is characterized by comprising the following steps: S001 multicomponent conductive concrete raw material prefabrication and performance regulation and control The core of the step is that according to the layering gradient formula, the accurate preparation and performance optimization of the conductive concrete raw materials in each region are completed, and the accurate matching of the materials with the functional requirements of the corresponding region in the aspects of conductivity, mechanical strength and aging resistance is ensured; the core pressure-bearing flow-dispersing area takes ordinary Portland cement as a matrix, and the mass percentage of the ordinary Portland cement to the mass of the ordinary Portland cement is 2.5 percent of copper-plated steel fiber, 0.08 percent of graphene oxide and 1.8 percent of expanded graphite are mixed, and 0.4 percent of hindered phenol antioxidant and 0.3 percent of gamma-aminopropyl triethoxy silane coupling agent are added; the secondary flow dispersing buffer area adopts ordinary silicate cement, wherein the mass percentage of the secondary flow dispersing buffer area is 1.8 percent of 316L stainless steel fiber, 15 percent of crystalline flake graphite, 3 percent of metakaolin and 0.3 percent of phosphite antioxidant are mixed with the mass percentage of the ordinary silicate cement; The stable supporting area takes ordinary Portland cement as a matrix, and the following percentages are 1.2% of ordinary steel fiber, 12% of natural graphite and 15% of fly ash relative to the mass of the ordinary Portland cement; Aiming at graphene oxide, ultrasonic dispersion treatment is needed first, and ultrasonic power is set Time of dispersion Ensure the interlayer spacing The conductive phase materials such as steel fiber, graphite and the like are pretreated by adopting a silane coupling agent, and the soaking time is prolonged After that, at Drying at a temperature of DEG C So as to improve the interfacial adhesion between the conductive phase material and the cement matrix; The stirring process is to follow the principle of step-by-step feeding and gradient accelerating, firstly, cement and aggregate are put into a stirrer for dry stirring Adding pretreated fiber and graphite, and stirring Finally, adding antioxidant, coupling agent and quantitative mixing water, and adjusting the stirring speed to be equal to Continuous stirring After the stirring is finished, the workability of the concrete is detected to ensure the expansion degree The requirement of subsequent pouring construction is met, meanwhile, the uniform distribution of all components is realized through the process, and a material foundation is laid for the excellent lightning current impact resistance of the concrete; s002 mould is built and function assembly is accurate lays Through the high-precision die construction and the scientific layout of the functional components, structural support is provided for the follow-up concrete pouring and the whole performance of the foundation, the accurate positioning and the cooperative work of core functional modules such as a dispersion system, a monitoring system and the like are ensured, firstly, the customization and the installation of a modularized steel die are carried out, the dimension of the die is required to be strictly matched with basic design parameters, the dimension error is controlled within +/-2 mm, the inner surface of the die is uniformly coated with a release agent, and the thickness of the release agent is controlled within +/-2 mm The smooth demoulding after the subsequent concrete pouring and forming can be ensured, and the foundation surface structure is not damaged; The installation of the dispersing system is one of the key links of the step, the dispersing cap titanium alloy framework at the top of the main column is required to be accurately fixed at the center position of the top of the die, the framework adopts a hollow net structure design, and the hollow rate is high The structure is ensured to be light, and an efficient diffusion channel can be provided for lightning current, and the thickness of the graphene conductive coating sprayed on the surface of the graphene conductive coating is required to be strictly controlled To improve the conductivity, the annular copper diffusion tube net needs to be separated according to the design space The pipe network is tightly connected with the main ribs through the conductive clamp, the connection part is required to be subjected to conductivity detection, and the contact resistance is ensured The smooth shunt of lightning current is prevented from being influenced by overlarge contact resistance; the sensor layout needs to be compatible with the monitoring precision and the installation stability, and the FBG fiber grating sensor adopts an S-shaped layout mode and has a layout density I.e. a monitoring point is arranged every 100mm, and the sensor is fixed in depth The special fixture is fixed with the inner wall of the die to prevent displacement in the pouring process, and after the arrangement is completed, a stress-strain calibration formula is needed to be utilized The sensor is calibrated accurately, the temperature measurement accuracy reaches +/-0.1 ℃ and the strain measurement accuracy reaches +/-1 mu epsilon, reliable data support is provided for damage monitoring under subsequent lightning current impulse, wherein E is the elastic modulus of conductive concrete, S is the sensitivity of a sensing grating, In addition, functional components such as a graphite electrode of the intelligent ground resistance adjusting module, a grouting pipe of the self-repairing system and the like are also required to be accurately pre-buried according to the design position, so that each component is ensured to be tightly combined with a concrete matrix, and the preset function of each component is exerted; s003 layered pouring vibration and gradient curing control The pouring work is strictly followed by the sequence from top to bottom of the bottom plate, the steps and the main column, the sequence can avoid the structural deformation of the lower layer concrete caused by the pouring pressure of the upper layer, and the pouring speed is controlled at The method ensures that the concrete can uniformly fill the mould and avoids the phenomenon of pouring non-fullness or segregation, and the vibration link adopts a high-frequency inserted vibrator, and the vibration frequency is set as The vibrating time is controlled according to 30s at each position, and the vibrating distance is kept at In the vibrating process, the vibrator needs to be quickly inserted and pulled out, the insertion depth is 50mm below the surface of the lower concrete layer, the tight combination of the upper concrete layer and the lower concrete layer is ensured, and the vibrator passes through a concrete compactness accounting formula after the vibrating is completed Detecting compactness, wherein m is the mass of a concrete test piece, and V is the volume of the test piece, and the requirement is satisfied The phenomenon that the conductivity and the mechanical strength are influenced due to excessive internal pores caused by insufficient compactness is prevented; The curing process is divided into two stages of standard curing and damp-heat curing, wherein the standard curing stage needs to be covered with a moisturizing film to keep the concrete surface moist, and the environmental temperature is controlled at DEG C, relative humidity Curing time The stage mainly ensures the stable increase of the early strength of the concrete, and the wet heat curing stage needs to raise the ambient temperature to C, relative humidity is maintained at The curing time is prolonged to The cement hydration reaction is accelerated through a high-temperature high-humidity environment, the later strength and the interfacial adhesion of the concrete are improved, and the curing process is required to be based on a concrete strength increase formula The strength development condition is monitored regularly, the compressive strength of the concrete cube after 28 days of curing is ensured to meet the design requirement, and strength support is provided for bearing lightning current impact and long-term service on the basis, wherein In order to maintain the compressive strength for t days, Is a standard compressive strength of 28 days, and the product has a high strength, ; S004 intelligent management and control system installation and cooperative test S004, focusing on hardware deployment, software configuration and multi-module collaborative performance verification of an intelligent management and control system, ensuring that the system can sense basic state under lightning current impact in real time and rapidly start a protection and repair mechanism through accurate parameter setting and functional test, firstly, installing a remote monitoring platform and deploying a sensor network, wherein the platform is required to have the functions of data real-time receiving, analyzing and instruction issuing, and temperature, strain and resistance data acquired by a sensor are sent to an edge computing gateway through a LoRa wireless transmission module, and the transmission power is set as follows Ensuring transmission distance under complex terrain Data sampling frequency The gateway carries out noise reduction and filtering treatment on the original data, and then uploads the data to a remote monitoring platform, and a platform database needs to reserve the historical data storage capacity for at least 10 years to support data backtracking and trend analysis; The debugging of the graphite electrode regulating module is one of the key links of the step, the module consists of 12 telescopic graphite electrodes and a stepping motor driving system, and the corresponding relation between the extending length of the electrodes and the grounding resistance is calibrated during the debugging, and the graphite electrode regulating module is calculated by a grounding resistance calculation formula Wherein The method is characterized in that the soil resistivity is L, the electrode insertion depth is L, the electrode cross section is S, the influence of the electrode extension length on the resistance is tested under different soil environments, and the driving voltage of the stepping motor is ensured When the electrode extends out, the electrode extension length adjustment precision reaches After debugging is completed, the abnormal lifting scene of the ground resistance is simulated, and whether the platform can automatically send an adjusting instruction is verified, so that the ground resistance is stabilized at a target value of less than or equal to 0.3 omega; The functional test of the self-repairing system is carried out on a microcosmic layer and a macroscopic layer, and in the microcosmic self-repairing test, the width is prefabricated manually The microcrack of urea-formaldehyde resin microcapsule is observed, and the fracture rate is required And forming a continuous repair film on the surface of the crack within 24 hours, verifying that the conductivity recovery rate of the repair area is more than or equal to 90% through a resistivity test, starting a high-pressure grouting system for cracks with the width of more than 0.3mm according to a macroscopic self-repair test, and setting grouting pressure Flow rate of grouting The slurry diffusion range and crack plugging effect of the grouting pipe are tested, and the recovery rate of the compressive strength of the repaired crack area is ensured to be more than or equal to 90%; Finally, carrying out system collaborative joint debugging, simulating a peak 50kA lightning current impact scene, verifying the linkage response performance of a sensor early warning, a platform decision, electrode regulation and a self-repairing system, wherein the sensor is required to trigger early warning within 1s after impact, the platform completes data analysis within 3s and issues instructions, the electrode regulation system reduces the grounding resistance to a safe range within 10s, if a macrocrack is detected, the self-repairing system needs to start grouting repairing within 30 min; s005 extreme environment adaptation structure strengthening treatment For a high-cold frozen soil area, the core is to solve the problems of damage to a foundation structure caused by frost heaving force and sudden rise of ground resistance caused by low temperature, an extruded sheet-conductive concrete-foaming polyurethane composite antifreezing layer is paved below a bottom plate during construction, the total thickness is strictly controlled to be 300mm, wherein the extruded sheet with the thickness of 150mm at the lower layer is used as a heat insulation barrier, and the heat conductivity coefficient is less than or equal to 0.028 The conductive concrete with the thickness of 100mm in the middle layer is mixed with 5 percent of calcium chloride snow-melting agent according to the proportion, and the mixing amount formula is that The insulation effect is further enhanced by slowly releasing chloride ions to prevent the surrounding soil of the foundation from freezing, the upper layer of 50mm thick foaming polyurethane has a closed pore rate of more than or equal to 90 percent, and meanwhile, the outer side of the main column is coated with 15mm thick conductive insulation coating which is formed by mixing graphite powder, acrylic ester emulsion and hollow glass beads according to a mass ratio of 2:6:2; The reinforcement key point of the coastal high salt spray area is to inhibit damage of salt spray corrosion to steel bars and conductive phase materials, firstly, all steel fibers in a foundation are replaced by marine duplex stainless steel fibers, the salt spray corrosion resistance level of the steel fibers is verified by a 2000h salt spray test, the corrosion rate is less than or equal to 0.05%, the main reinforcement is subjected to double corrosion prevention treatment of hot galvanizing and epoxy coating, the thickness of the coating is more than or equal to 200 mu m, no obvious corrosion occurs in a salt spray environment within 10 years, the outer surface of the foundation is coated with a polyurea-graphite composite corrosion prevention coating with the thickness of 3mm, the mass ratio of the polyurea to the graphite is 7:3, the concrete surface is subjected to sand blasting treatment before the coating, the roughness reaches Sa2.5 level, the adhesion of the coating is ensured to be more than or equal to 6MPa, the coating is used as a physical barrier to isolate salt spray corrosion, the surface conductive performance is maintained by graphite particles, and after 1000h salt spray aging test, the conductive performance attenuation is controlled within 5%, and the lightning current flow efficiency is not affected; The shear resistance and the earthquake resistance of the foundation are required to be enhanced in a strong earthquake area, the synergistic effect of earthquake load and lightning current impact is responded, a Q460 high-strength steel rib-conductive concrete combined shear key is arranged at the joint of a main column and a step, the section size of the steel rib is 150mm multiplied by 150mm, the depth of the embedded main column is 400mm, the embedded main column is fixed by embedded anchor bolts with the diameter of 20mm, the distance between the anchor bolts is 100mm, a steel-concrete synergistic stress system is formed, and the shear bearing capacity is calculated according to the formula Calculation of wherein The axial tensile strength of the conductive concrete, b is the width of the section of the shear key, The vibration table test simulating 0.4g of earthquake acceleration proves that the maximum displacement of the foundation is less than or equal to 5mm, and each connecting part is not cracked, thereby meeting the design requirement of the VIII level of the earthquake intensity; The whole strengthening treatment process needs to dynamically adjust the construction process by combining environmental parameters, for example, an antifreezing layer is constructed when the daytime temperature is more than or equal to 5 ℃, the coastal area coating construction needs to avoid high humidity weather, the relative humidity is less than or equal to 85%, ultrasonic flaw detection needs to be carried out after the shear key of the strong earthquake area is installed, so that each strengthening structure and a foundation body form an organic whole, and the dual functions of lightning current impact resistance and environmental adaptation are simultaneously exerted in extreme environments; S006 overall performance comprehensive detection acceptance The lightning current impulse performance test is the core of the step, the lightning stroke strength possibly encountered by the actual transmission line needs to be simulated, and the peak value is applied Standard lightning current with waveform of 8/20 mu s, wavefront time of 8 mu s and half peak time of 20 mu s, collecting data by using pre-buried FBG optical fiber sensor and stress sensor, and monitoring maximum stress value of core pressure-bearing flow-dispersing area in test according to stress calculation formula Accounting, wherein F is impulse force generated by lightning current impulse, A is stress area, and maximum stress is required The stress distribution uniformity error is less than or equal to 10 percent, and simultaneously the time from the injection to the complete release of the lightning current is recorded through a high-speed data acquisition system Is required to meet The method comprises the steps of determining the flow scattering efficiency of a multi-path flow scattering system, verifying the effectiveness of the multi-path flow scattering system, wherein the flow scattering efficiency is equal to or more than 95% and is the ratio of the actual flow scattering rate to the injection rate, and taking the average value of 3 tests as a final result at 30min intervals of each test in order to ensure the test accuracy, wherein the deviation between single test data and the average value is equal to or less than 5%; The intelligent system joint debugging test needs to construct a full-flow verification scene of damage simulation-data transmission-decision execution, and the early warning response performance of the sensor network is tested by manually prefabricating the width of microcracks by 0.1-0.4 mm or applying external resistance interference, namely, the response time of the temperature sensor is required to be higher than or equal to 5 ℃ when the ambient temperature is suddenly changed The strain sensor has early warning accuracy of 100% when stress exceeds 0.0015, data packet loss rate of the LoRa module within 1km distance is required to be verified to be less than or equal to 1% in a data transmission link, data analysis delay of an edge calculation gateway is less than or equal to 2s, an intelligent grounding resistance adjusting module is required to return resistance to a target value within 10s when grounding resistance exceeds 0.3 omega in an execution mechanism test, adjusting accuracy error is less than or equal to 0.02 omega, and crack plugging rate within 24 hours is required to be detected by a self-repairing system when 0.3mm crack is detected by the self-repairing system The deviation between the resistivity of the repair area and the original area is less than or equal to 10 percent; the extreme environment simulation test needs to set special tests aiming at different adaptation scenes, the cold region test adopts a freeze thawing cycle test of-40 ℃ to 20 ℃ for 50 cycles, and the compression strength loss rate formula is adopted Assessment of requirements , In order to achieve an initial compressive strength, the steel sheet is, The salt fog aging test of 5% NaCl solution with mass concentration is adopted in coastal high salt fog area test, and the formula of the corrosion rate of the steel bars is passed for 2000 hours The accounting is performed on the data of the data, For the initial mass of the steel bar, For the quality after test, require The coating adhesive force retention rate is more than or equal to 80%, the earthquake load of 0.4g acceleration is simulated through a vibrating table in a strong earthquake area test, the duration is 30s, the maximum displacement of a test foundation is less than or equal to 5mm, the shear bearing capacity attenuation rate of a shear key is less than or equal to 10%, and the stability of the structure under the synergistic effect of earthquake and lightning stroke is verified; after all the tests are completed, all the data are collected to form a comprehensive evaluation report containing lightning current impulse parameters, intelligent system response indexes and extreme environmental performance attenuation rate, all the indexes can pass through acceptance inspection when all the indexes meet design requirements, the reasons of the substandard items are required to be analyzed and are modified, and the test is repeated until the substandard items are qualified after the modification, so that the foundation is ensured to stably play the functions of lightning current impulse resistance and environmental adaptation in the whole life cycle.
7. 7. The method for constructing a conductive concrete tower foundation resistant to lightning current surge of claim 6, wherein in step S001, the aspect ratio of the copper-plated steel fibers is controlled to be Length of Straight and long 。

Description

Lightning current impulse resistant conductive concrete pole tower foundation and construction method thereof Technical Field The invention relates to the technical field of power system transmission line grounding engineering, in particular to cross application of conductive composite material modification, lightning current multi-physical field coupling protection, intelligent monitoring and active repair technology, which is particularly suitable for the foundation construction of a transmission line tower in extreme environments such as high-resistivity complex terrain, high-cold soil, coastal high-salt fog, strong earthquake and the like, can realize efficient lightning current dispersion, accurate early warning and autonomous repair of damage, and remarkably improves the impact stability and full life cycle service performance of the tower foundation. Background Along with the acceleration of global energy internet construction, the coverage range of the ultra-high voltage and ultra-high voltage transmission line is continuously enlarged, line site selection gradually extends to remote areas with high altitude, high resistivity and complex terrain, and the problems of exposed rock, barren soil, bad meteorological conditions and the like of the areas generally exist, so that a serious challenge is brought to the construction of a grounding system of a transmission line tower foundation. The traditional tower foundation is mostly made of common concrete materials, and the resistivity of the traditional tower foundation is as high asAbove, the conductivity is extremely poor, so that the grounding resistance is difficult to meet the requirements of the grounding design specification of alternating current electric devices, lightning current cannot be quickly dissipated, serious accidents such as pole tower counterflashover, equipment damage and the like are easily caused, and the safe and stable operation of a power system is threatened. In order to solve the problem of insufficient grounding performance of the common concrete foundation, the engineering field sequentially adopts the technical means of chemical resistance-reducing agent laying, external grounding electrode leading, grounding network area expanding and the like. However, the scheme has a plurality of inherent defects that corrosive components in the chemical resistance reducing agent easily permeate into soil to cause groundwater and soil pollution, the phenomenon of loss and hardening easily occurs after long-term operation to greatly attenuate the resistance reducing effect, the external grounding electrode is obviously limited by terrain, the construction difficulty is extremely high in complex terrains such as mountain areas, canyons and the like, the consumable amount is large, the cost is high, a large amount of land resources are required to be occupied when the area of a grounding network is enlarged, the construction period and the later maintenance workload are increased at the same time when the area of the grounding network is hard to implement in areas with strict farmland protection and land resource shortage. The conductive concrete is used as a novel composite functional material, and by virtue of the advantages of the structural support performance and the good conductive performance of the common concrete, the conductive concrete gradually becomes an ideal choice of the integrated grounding body of the tower foundation. The resistivity of the concrete can be reduced by doping conductive phase materials such as graphite, steel fiber, carbon fiber and the like into common concreteIn addition, the integrated function of supporting and grounding of the tower foundation is realized, an additional grounding electrode is not required to be constructed, and various defects of the traditional grounding scheme are effectively overcome. In practical engineering application, the conductive concrete pole tower foundation is subjected to serious damage caused by lightning current impact, wherein the peak value of the lightning current can reach tens to hundreds of kiloamperes, when the lightning current is dissipated through the foundation, a strong electric heating effect can be generated due to the existence of internal resistance of the conductive concrete, the instantaneous temperature rise can reach hundreds of degrees celsius, remarkable thermal expansion is caused, and the thermal expansion is uneven due to the difference of material characteristics and structural constraints of all parts of the foundation, so that huge thermal stress is generated, the initiation, the expansion and the penetration of microcracks in the concrete are caused, the integrity of a dissipation channel is damaged, the mechanical strength and the conductivity of the foundation are reduced, and even the foundation structure is invalid when the lightning current is severe, so that the service life of the pole tower foundation is greatly shortened. The exis