A distribution network vertical ground electrode deep driving control method

Abstract

The application provides a vertical ground electrode deep driving control method, comprising: synchronously collecting the rod body downstroke, in-situ holding time, axial rebound trajectory and ground resistance curve in the pressure stopping window through the pressure stopping driving head and resistance sampling probe, and respectively counting the soil penetration depth record, ground resistance sampling record and rod body rebound displacement; according to the ground resistance sampling record and the soil penetration depth record, extracting the construction section with continuously rising ground resistance and increasing depth, and taking the section as the buried depth determination basis for the electrode outer wall and the hole wall soil body adhesion weakening; integrating the real penetration determination result, the rod body rebound displacement and the ground resistance sampling record to form the penetration state record, and generating the driving force adjustment signal according to the penetration state record, wherein the driving force adjustment signal comprises the downshift pressure increasing adjustment signal and the upshift pressure stabilizing adjustment signal.

Description

Technical Field

[0001] This invention relates to the field of information technology, and in particular to a method for driving and controlling the burial depth of vertical grounding electrodes in power distribution networks. Background Technology

[0002] In the field of power distribution network construction, the performance of grounding devices directly affects the safety and stability of power grid operation, and their importance is self-evident. Grounding devices ensure that equipment and personnel are protected from lightning strikes or fault currents by guiding current into the earth. The burial depth of the vertical grounding electrode is a critical element that profoundly influences the final effect of grounding resistance. If the grounding resistance fails to meet design requirements, it may lead to protection failure, thereby threatening the safety of the entire system.

[0003] However, existing methods have significant shortcomings in controlling burial depth and optimizing grounding resistance. Many traditional schemes often neglect the impact of dynamic changes in the soil environment and grounding electrode during construction, focusing only on the surface effects of increased burial depth without considering complex factors such as soil relaxation and changes in contact state. This neglect leads to deviations in judging the relationship between burial depth and resistance during construction, often resulting in the contradictory phenomenon of resistance increasing instead of decreasing with increasing burial depth. In particular, during the pressing process of the grounding electrode, the contact state between the pole and the soil changes due to the rebound after pressing stops and soil relaxation. Pole rebound refers to the slight upward movement of the grounding electrode due to the reaction force of the soil after pressing stops, while soil relaxation refers to the loosening of the soil around the borehole wall after pressure release, resulting in a reduced adhesion between the outer wall of the grounding electrode and the soil. This deterioration of the contact state can disrupt the conductive path between the two, such as destroying the existing aquifer and hindering current transmission, thus causing abnormal fluctuations or increases in grounding resistance.

[0004] Specifically, in actual construction, once the grounding electrode is driven to a certain depth, if the driving is paused to observe the effect, the pole may spring back, creating tiny gaps between itself and the soil. The soil may also become loose and unable to tightly enclose the grounding electrode. In this situation, even if the burial depth is increased further, the resistance value may increase instead of decrease, creating a perplexing contradiction. Construction workers often struggle to determine whether to continue driving or adjust their strategy; blind operation may lead to wasted resources or even construction failure.

[0005] Therefore, accurately identifying the impact of pole rebound and soil relaxation on the contact state during construction, and dynamically adjusting the burial depth control strategy accordingly, has become a key issue in improving the performance and construction efficiency of grounding devices. Summary of the Invention

[0006] This invention provides a method for driving and controlling the burial depth of vertical grounding electrodes in a distribution network, the method comprising:

[0007] The rod's downward stroke, in-situ holding time, axial rebound trajectory, and grounding resistance curve are simultaneously collected within the pressure-stopping window using a pressure-stopping drive head and a resistance sampling probe, resulting in soil penetration depth records, grounding resistance sampling records, and rod rebound displacement.

[0008] Based on the grounding resistance sampling records and soil penetration depth records, construction sections where the grounding resistance continues to rise while the depth is still increasing are extracted as the basis for determining the burial depth.

[0009] Based on the burial depth determination criteria, soil penetration depth records, grounding resistance sampling records, and pole rebound displacement, the construction sections with grounding resistance continuously decreasing with the pressing stroke, remaining low during the in-situ holding period, and continuously increasing soil penetration depth, and whose rebound after stopping pressing did not offset the net soil penetration increment of this window, were extracted and marked as effective penetration sections.

[0010] By comparing the effective penetration interval in the burial depth determination criteria, the construction section that is identified as a gravel top support interference section is determined and eliminated, and the actual penetration determination result is formed.

[0011] The actual penetration determination results, rod rebound displacement and grounding resistance sampling records are integrated to form a penetration status record. Based on the penetration status record, a driving force adjustment signal is generated, which includes a downshift boost adjustment signal and an upshift voltage stabilization adjustment signal.

[0012] The driving force adjustment signal is used to update the pressure speed level. The sampling process within the pressure stop window is re-executed according to the updated speed level. The final penetration identification is completed based on the fall of the ground resistance curve and the continuation of the effective penetration interval.

[0013] Preferably, the step of simultaneously acquiring the rod's downward stroke, in-situ holding time, axial rebound trajectory, and grounding resistance curve within the pressure-stopping window using a pressure-stopping drive head and a resistance sampling probe to obtain soil penetration depth records, grounding resistance sampling records, and rod rebound displacement includes:

[0014] The pressure-stopping window is opened according to the preset sampling cycle. The displacement sensor records the displacement sequence of the rod relative to the borehole reference plane point by point and the in-situ holding state is included in the soil penetration depth record.

[0015] The resistance sampling probe continuously samples the grounding resistance, and the samples are then filtered by the sliding median and archived as the grounding resistance sampling record.

[0016] The displacement difference between the peak upward sampling point of the axial rebound trajectory and the end sampling point of the rebound is taken as the rebound displacement of the rod.

[0017] Preferably, the step of extracting construction sections where the grounding resistance is continuously rising and the depth is still increasing, based on grounding resistance sampling records and burial depth records, as the basis for determining burial depth includes:

[0018] The grounding resistance sampling records are paired point by point with the soil penetration depth records according to the timestamp, and continuous sampling segments in which the resistance difference is continuously positive and higher than the resistance rise threshold, and the depth difference is also positive are extracted.

[0019] The ratio of the cumulative increase in resistance to the cumulative increase in burial depth within the continuous sampling segment is taken, and the segment whose ratio is continuously higher than the fit threshold is marked as the basis for determining the burial depth.

[0020] Preferably, the construction section that combines the burial depth determination criteria, soil penetration depth records, grounding resistance sampling records, and pole rebound displacement to extract the section where the grounding resistance continuously decreases with the downward stroke, remains low during the in-situ holding period, continuously increases in soil penetration depth, and the rebound after pressure cessation does not offset the net soil penetration increment of this window, is marked as the effective penetration section, including:

[0021] For grounding resistance curves that do not fall within the burial depth determination criteria, the difference between adjacent sampling points is taken. Segments where the percentage of fallback during the down-pressure period and the fallback amplitude are both higher than a preset threshold are determined as continuous fallback down-pressure segments.

[0022] When the rise of the resistance relative to the end point of the continuous falling down pressure segment is lower than a preset threshold during the in-situ holding time of the segment, it is determined to be a low-position holding segment, which is then spliced ​​with the continuous falling down pressure segment to form a verification segment.

[0023] The effective penetration interval is defined as the segment within the verification section where the soil penetration depth sequence continuously increases and the net soil penetration increment is higher than the rebound value.

[0024] Preferably, the step of comparing the effective penetration interval in the burial depth determination criteria, identifying construction sections where the rod rebound displacement is greater than the incremental pressure stroke in this window, the rod tip has not formed a net penetration depth, and the grounding resistance remains the same or increases, and determining these sections as gravel top-support interference sections and eliminating them, thus forming a true penetration determination result, includes:

[0025] The construction sections marked as the effective penetration intervals are deducted from the burial depth determination criteria, and the remaining construction sections are summarized as sections to be verified.

[0026] For each pressure-stopping window in the section to be verified, the grounding resistance curve, the soil penetration depth sequence, and the rebound displacement sequence are extracted from the grounding resistance sampling record, the soil penetration depth record, and the pole rebound displacement, respectively.

[0027] The difference between the beginning and end of the soil penetration depth sequence during the pressure duration is taken as the pressure stroke increment of this window, and the difference between the beginning and end of the pressure cessation window is taken as the net soil penetration increment of this window. The difference between the beginning and end of the grounding resistance curve at the same pressure cessation window is taken as the final state change of resistance.

[0028] The rebound displacement sequence is input into the extreme value search algorithm, and the rebound value is obtained by subtracting the initial displacement value at the start time from the maximum displacement value.

[0029] A window whose rebound value is greater than the incremental pressure stroke of the window, whose net soil penetration increment of the window is not greater than zero, and whose final resistance change is not less than zero is identified as a suspected top support window.

[0030] The sub-segments where the suspected top support window appears consecutively are determined to be the gravel top support interference sections. After being removed, the remaining construction sections are summarized as the actual penetration determination results.

[0031] Preferably, the integration of the actual penetration determination result, the rod rebound displacement, and the grounding resistance sampling record forms a penetration state record. A driving force adjustment signal is generated based on the penetration state record. The driving force adjustment signal includes a downshift boost adjustment signal and an upshift stabilization adjustment signal, comprising:

[0032] The actual penetration determination result, the rod rebound displacement, and the grounding resistance sampling record are paired with the same timestamp. Three types of entries are registered in each pressure-stopping window: the first type of entry records whether the current pressure-stopping window is included in the effective penetration interval of the actual penetration determination result; the second type of entry records the rebound value of the rod rebound displacement corresponding to the current pressure-stopping window; and the third type of entry takes the difference between the values ​​of the grounding resistance sampling record at the start and end times of the current pressure-stopping window as the final state change of the resistance. The three types of entries are connected in series in chronological order to form the penetration state record.

[0033] When the pressure stop window does not fall into the effective penetration range, the rebound value exceeds the preset rebound threshold, and the final state change of the resistance is not less than zero, the corresponding downshift boost adjustment signal is output.

[0034] When the voltage stop window falls within the effective penetration range and the final change in resistance is less than zero, the corresponding up-level voltage regulation signal is output.

[0035] Preferably, the step of updating the pressure speed level using a driving force adjustment signal, re-executing the sampling process within the pressure-stopping window according to the updated speed level, and completing the final penetration identification based on the fallback of the grounding resistance curve and the continuation of the effective penetration interval includes:

[0036] The downshifting and boosting adjustment signal will lower the downshifting speed by one level and increase the hydraulic output pressure by a preset amplitude.

[0037] The upshift and pressure regulation signal will increase the downshift speed gear by one level and maintain the current value of the hydraulic output pressure.

[0038] According to the updated pressing speed gear and hydraulic output pressure, drive the pressure stop drive head to enter the retest pressure stop window, and re-collect the retest pressing stroke, retest holding time, retest rebound trajectory and retest grounding resistance curve;

[0039] The difference between the first and last values ​​of the retested grounding resistance curve is taken as the resistance drop amplitude. When the resistance drop amplitude is higher than the preset stable drop threshold and the retested voltage stop window continuously meets the three conditions of resistance drop during the voltage drop period, low position maintenance in the original position, and rebound not being offset, and the effective penetration interval continues to the future, it is recorded as the final penetration identification result.

[0040] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:

[0041] This invention discloses a method for driving and controlling the burial depth of vertical grounding electrodes in power distribution networks. It addresses the problem of difficulty in accurately determining the true penetration state and affecting the adjustment of driving force during grounding electrode construction due to weakened soil adhesion and interference from underground gravel. This invention simultaneously collects data on the pressing stroke, rebound trajectory, and grounding resistance curve. It analyzes the relationship between resistance and depth to extract the effective penetration range and accurately identifies and eliminates gravel-affected sections with large rebounds and incomplete soil penetration, obtaining the true penetration determination result. Subsequently, based on this result, it generates down-level boosting or up-level stabilizing signals to dynamically update the pressing speed level. This invention effectively eliminates the influence of complex geological interference on misjudgment of the penetration state, achieves adaptive and precise adjustment of the driving force, ensures stable adhesion between the electrode and the borehole wall soil, and significantly improves the construction quality and grounding performance of the grounding electrode. Attached Figure Description

[0042] Figure 1 This is a flowchart of a method for driving and controlling the burial depth of vertical grounding electrodes in a power distribution network according to the present invention.

[0043] Figure 2 This is a schematic diagram of a method for driving and controlling the burial depth of vertical grounding electrodes in a distribution network according to the present invention.

[0044] Figure 3 This is another schematic diagram of a power distribution network vertical grounding electrode burial depth drive control method according to the present invention. Detailed Implementation

[0045] To further understand the content of this invention, a detailed description of the invention is provided in conjunction with the accompanying drawings and embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. It should also be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0046] like Figures 1-3 This embodiment of a method for driving and controlling the burial depth of a vertical grounding electrode in a distribution network may specifically include:

[0047] S101. The rod's downward stroke, in-situ holding time, axial rebound trajectory, and grounding resistance curve are simultaneously collected within the pressure-stopping window using the pressure-stopping drive head and resistance sampling probe. The soil penetration depth record, grounding resistance sampling record, and rod rebound displacement are statistically obtained respectively.

[0048] During the continuous downward movement of the grounding electrode pole by the pressure-stopping drive head, a pressure-stopping window is opened according to a preset sampling period. Within this window, the pressure-stopping drive head records the downward stroke of the pole point by point using a built-in displacement sensor, obtaining a displacement sequence of the pole relative to the borehole reference plane. Simultaneously, the duration of the pressure-stopping drive head entering the in-situ holding state is timed. The displacement sequence and holding duration are aligned with a unified timestamp and then included in the soil penetration depth record. Within the same pressure-stopping window formed by the soil penetration depth record, a resistance sampling probe deployed on the pole surface continuously samples the grounding resistance between the grounding electrode and the far-end auxiliary electrode. Aligned with the same timestamp and the displacement sequence and holding duration, a grounding resistance curve showing the change in grounding resistance with the downward stroke and in-situ holding duration is obtained. After removing spikes and jumps by applying a sliding median filter to the discrete sampling points of the grounding resistance curve within the pressure-stopping window, these are sequentially archived as grounding resistance sampling records. For the period when the pressure-stopping drive head stops applying downward pressure during the in-situ holding time, the displacement sensor tracks the slight upward movement of the rod along the axial direction to obtain the axial rebound trajectory within the pressure-stopping window. The displacement difference between the peak upward movement sampling point and the rebound end sampling point on the axial rebound trajectory is taken as the rod rebound displacement. The rod rebound displacement is integrated with the soil penetration depth record and the grounding resistance sampling record at the same timestamp to complete the synchronous acquisition and classification statistics of the pressure stroke, in-situ holding time, axial rebound trajectory and grounding resistance curve.

[0049] It should be noted that during the construction of the power distribution network grounding device, the vertical grounding electrode is pressed into the pre-drilled hole by a hydraulic drive head. The pressure-stopping drive head integrates a hydraulic cylinder, a pressure sensor, and a displacement sensor. The resistance sampling probe is installed close to the outer wall of the pole body through a clamp and connected to the three-electrode grounding resistance tester via a lead wire. The remote auxiliary electrode and voltage electrode are installed at the specified distance on the outside of the soil around the pole body, forming the physical layout required for synchronous data acquisition. In one embodiment, the opening of the pressure-stopping window adopts a fixed stroke triggering method. When the pressure-stopping drive head detects that the cumulative downward stroke of the pole body has reached a preset step length, for example, every time the pole body is pushed in 30 to 50 centimeters, the hydraulic output switches to a pressure-holding state, and the pressure-stopping window opens immediately. The closing of the pressure-stopping window is determined by the earlier of two conditions: the in-situ holding time reaching a preset upper limit or the start of the next downward pressing action. Each pressure-stopping window corresponds to a set of homologous sampling data of downward stroke, holding time, rebound trajectory, and grounding resistance curve.

[0050] Furthermore, the preset step size and the preset upper limit of the in-situ holding time are adaptively optimized and adjusted according to the current geological conditions. At the beginning of each pressing action, the pressure rise slope of the pressure sensor built into the pressure-stopping drive head within a unit stroke is extracted, and the initial grounding resistance base value measured by the resistance sampling probe is combined to determine the current soil compaction level. If the pressure rise slope is greater than the preset slope threshold and the initial grounding resistance is higher than the preset resistance base, it is determined to be a hard gravel layer. The preset step size is reduced to 30 cm, and the preset upper limit of the in-situ holding time is extended to 20 seconds to fully capture the delayed rebound and resistance relaxation characteristics of the rod under hard soil. If the pressure rise slope is less than the preset slope threshold and the initial grounding resistance is lower than the preset resistance base, it is determined to be a soft clay layer. The preset step size is increased to 50 cm, and the preset upper limit of the in-situ holding time is shortened to 10 seconds to avoid severe diameter reduction of soft soil due to prolonged pressure stop.

[0051] Specifically, the displacement sensor is a magnetostrictive displacement gauge or a draw-wire encoder, installed between the piston rod of the pressure-stopping drive head and the frame. It outputs the displacement value of the top of the rod relative to the orifice reference plane. The sampling frequency is preferably higher than 100 Hz. The continuous displacement readings of each pressing process constitute the displacement sequence. The displacement sequence is intercepted at the end of the pressure-stopping window to obtain complete displacement data during the entire pressure-stopping window. It is written into the soil depth record along with the timestamp. The soil depth record synchronously records the start time and duration of the pressure-stopping drive head entering the pressure-holding state.

[0052] It is understood that the sampling frequency of the resistance sampling probe within the pressure-stopping window is kept at the same clock source as the sampling frequency of the displacement sensor. The two are aligned through a unified timestamp allocated by the same data acquisition unit to avoid timing misalignment between multiple channels caused by clock drift.

[0053] For example, the original grounding resistance value measured by the resistance sampling probe may exhibit isolated spikes due to slight movement of the pole, fluctuations in soil moisture content, or external electromagnetic interference. To address this phenomenon, a sliding median filter is used to remove these spikes. The sliding median filter slides along the time axis with an odd-length window, and each time takes the median of all sampling points within the window as the output value of the window center point. For grounding resistance changes with a long duration and stable amplitude, the trend is preserved, while only single-point jumps are smoothed. The filtered grounding resistance data are archived sequentially according to timestamps to form the grounding resistance sampling record. The grounding resistance sampling record corresponds one-to-one with the displacement sequence and holding time in the soil penetration depth record, thus obtaining a complete characterization of the grounding resistance curve during the pressing stage and the in-situ holding stage.

[0054] In one embodiment, the acquisition of the axial rebound trajectory begins at the moment when the pressure-stopping drive head stops applying downward pressure, and the displacement sensor continuously tracks the slight upward movement of the rod along the axial direction until the pressure-stopping window closes.

[0055] Preferably, the upward peak sampling point is the sampling point in the axial rebound trajectory where the displacement value reaches its maximum. The process for obtaining the rebound end sampling point is as follows: determine whether there is a first sampling point in the latter part of the axial rebound trajectory where the displacement value changes by less than 0.1 mm within 0.5 seconds. If so, it is taken as the rebound end sampling point. If the first sampling point does not exist due to the early closure of the pressure-stopping window, the last sampling point before the pressure-stopping window is closed is taken as the rebound end sampling point. The difference between the displacement values ​​of the two sampling points is taken as the rod rebound displacement. The rod rebound displacement is listed separately and integrated with the soil penetration depth record and the grounding resistance sampling record under the timestamp of the pressure-stopping window to form a synchronous sampling data set.

[0056] It should be noted that for different soil sections such as gravel layer, clay layer, and backfill layer, the pressing speed setting of the pressure-stopping drive head and the preset step size of the pressure-stopping window can be set to smaller values ​​respectively, so that the displacement sequence, holding time, axial rebound trajectory and grounding resistance curve maintain a stable sampling density under different soil conditions. The synchronous sampling data set is used as input data in the subsequent penetration state determination stage. The synchronous acquisition and classification statistics of pressing stroke, in-situ holding time, axial rebound trajectory and grounding resistance curve are continuously completed in the successive advancement of the pressure-stopping window.

[0057] It should be further noted that all preset thresholds involved in the subsequent steps of this application are calculated based on the real-time physical data collected during the current pressure-stopping window, according to the following classification principles:

[0058] For preset thresholds involving changes in grounding resistance, including resistance change thresholds and preset stable fall-off thresholds, the calibration method is as follows: extract M consecutive sampling points when the current voltage cut-off window is open and the grounding resistance of the M sampling points is calculated as the base value, and calculate the root mean square of the absolute difference of the M sampling points as the background volatility; add 1.5 to 2 times the background volatility to the base value as the upper limit of the preset threshold involving resistance rise, and subtract 1.5 to 2 times the background volatility from the base value as the preset threshold involving resistance fall-off, such as the lower limit benchmark of the preset stable fall-off threshold;

[0059] For the preset thresholds involving proportions, including the fallback continuity threshold and the fallback amplitude threshold, they are set based on the degree of dispersion of resistance changes over time in at least three historical pressure-stopping windows completed before the current pressure-stopping window. The variance of the resistance difference in the historical windows is calculated. If the variance is greater than the preset dispersion benchmark, the current soil quality is determined to be uneven, and the fallback continuity threshold is set to 0.6 to allow for interference. If the variance is less than the preset dispersion benchmark, the soil quality is determined to be stable, and the threshold is set to 0.8.

[0060] For preset thresholds involving displacement, including rebound threshold and net soil penetration threshold, the actual hydraulic thrust of the pressure-stopping drive head during the current pressure duration is obtained. Combining the elastic modulus and cross-sectional area of ​​the grounding pole, Hooke's law is used to calculate the theoretical elastic compression of the pole under this thrust. This theoretical elastic compression is multiplied by a safety factor of 1.1 to obtain the rebound threshold for this window. The net soil penetration threshold is determined by multiplying the absolute value of the static measurement error of the displacement sensor by 2.

[0061] For the fit threshold involving the ratio of grounding resistance to depth, the basic calibration is performed based on the product of the static measured value of soil resistivity of the current soil section and the reciprocal of the pole diameter, and then fine-tuned by combining the initial grounding resistance base value during the current window of pressure.

[0062] S102. Based on the grounding resistance sampling record and the soil penetration depth record, extract the construction section where the grounding resistance continues to rise and the depth is still increasing, and use this section as the basis for determining the burial depth where the adhesion between the outer wall of the electrode and the soil of the borehole wall weakens.

[0063] The grounding resistance sampling records are paired point-by-point with the soil penetration depth records according to timestamps. Along the time axis, the differences between adjacent points of the grounding resistance and soil penetration depth values ​​are calculated. Continuous sampling segments where the resistance difference is continuously positive and exceeds a preset resistance rise threshold, and the depth difference remains positive, are extracted to obtain construction sections where the grounding resistance continuously increases and the soil penetration depth increases synchronously. For each construction section, the ratio of the cumulative rise of the grounding resistance sampling records to the cumulative increase of the soil penetration depth records within that section is compared to a preset fit threshold. If the ratio is consistently higher than the fit threshold, the fit between the electrode outer wall and the borehole wall soil within that section is determined to be weakened, and the construction section is marked as the basis for determining the burial depth.

[0064] In one implementation, the grounding resistance sampling record and the soil penetration depth record are sent to the data processing unit together after the pressure cessation window ends. They are paired point by point according to a unified timestamp to form a resistance-depth binary sequence. The resistance difference is obtained by subtracting the grounding resistance values ​​of two adjacent points along the time axis, and the depth difference is obtained by subtracting the soil penetration depth values ​​of two adjacent points. A positive resistance difference indicates that the grounding resistance is rising within the sampling interval, and a positive depth difference indicates that the rod is still penetrating the soil.

[0065] Specifically, the resistance rise threshold is used to eliminate low-amplitude noise disturbances caused by fluctuations in soil moisture content and minor displacements of backfill material. The preceding stable downward range refers to the sampling interval where, prior to the current sampling point, the first-order resistance difference values ​​of M consecutive sampling points are all less than 0, and the variance of these M differences is less than 0.05, where M ranges from 10 to 20. Preferably, 1.5 times the root mean square value of the absolute values ​​of adjacent resistance differences within this preceding stable downward range is taken as the resistance rise threshold. Only when the resistance difference is positive for 5 consecutive sampling points and the value is higher than the resistance rise threshold is the continuous sampling segment included as a candidate.

[0066] In one embodiment, the ratio of cumulative uplift to cumulative increment is further calculated for the construction section. The cumulative uplift is the net increase in resistance obtained by accumulating the resistance difference point by point within the section, and the cumulative increment is the net penetration depth of the rod obtained by accumulating the depth difference point by point within the section. The ratio reflects the increase in grounding resistance per unit penetration depth. The fit threshold is pre-calibrated based on the borehole diameter, backfill gradation, and soil resistivity. For example, a smaller fit threshold is used for gravel backfill sections, and a larger fit threshold is used for clay backfill sections. If the ratio is consistently higher than the fit threshold within the construction section, the conductive path between the outer wall of the electrode and the borehole wall soil is determined to be narrowed, and the construction section is marked as the basis for burial depth determination for subsequent penetration state identification.

[0067] S103. Based on the burial depth determination criteria, soil penetration depth records, grounding resistance sampling records, and pole rebound displacement, extract the construction sections where the grounding resistance continuously decreases with the downward pressure stroke, remains at a low level or continues to decrease during the in-situ holding period, and the soil penetration depth continuously increases and the rebound after pressure is stopped does not offset the net soil penetration increment in this window. These sections are marked as effective penetration intervals.

[0068] Take the grounding resistance curve corresponding to the downward stroke from the grounding resistance sampling record. For construction sections that do not fall into the burial depth determination criteria, take the resistance difference between adjacent sampling points. Statistically calculate the percentage and magnitude of the fall during the downward pressure period. If both are higher than the corresponding preset threshold, it is determined to be a continuous downward pressure section. For the in-situ holding time connecting the continuous downward pressure sections, extract the resistance sequence within this time from the grounding resistance sampling record. Take the resistance at the end of the downward pressure section as the reference resistance. If the percentage and magnitude of the rise of the resistance sequence relative to the reference resistance are both lower than the preset threshold, it is determined to be a low-position holding section, which is spliced ​​with the downward pressure section to form a verification section. For the verification section, take the net soil penetration increment from the difference between the first and last soil penetration sequences corresponding to the soil penetration depth record. Take the rebound value of this section from the rebound displacement of the pole. If the soil penetration depth sequence continuously increases and the net soil penetration increment is higher than the rebound value, then this section meets three conditions and is marked as a valid penetration interval.

[0069] It should be noted that during the grounding electrode pressing operation, whether the conductive path between the outer wall of the pole and the soil of the borehole wall has truly improved cannot be determined solely by the instantaneous decrease in grounding resistance during the pressing period. Pressing rebound and soil relaxation will cause the instantaneous decrease to be offset by the rebound after pressing stops. The resistance condition decline and the depth condition net entry must both be met simultaneously within the same pressing window for the electrode contact state to be considered to be evolving towards stability. In one embodiment, the grounding resistance sampling records are paired with the pressing stroke to obtain the grounding resistance curve. The pressing period is then divided according to each start and stop of the pressing drive head. For pressing periods not marked by the burial depth determination criteria, the resistance difference between adjacent sampling points is taken along the time axis of the grounding resistance curve. The proportion of sampling points with negative resistance differences to all sampling points in that pressing period is counted as the decline ratio. The absolute values ​​of the resistance differences of all sampling points with negative resistance differences are summed, and the resulting positive value is counted as the decline amplitude.

[0070] Specifically, the fallback continuity threshold and fallback amplitude threshold are pre-calibrated based on the soil section of the borehole. For example, in the gravel backfill section, the fallback ratio threshold during the compression period is 0.6 to 0.7, and the fallback amplitude threshold is 5% of the initial resistance of that section; in the clay backfill section, the fallback ratio threshold is 0.75 to 0.85, and the fallback amplitude threshold is 8% of the initial resistance of that section. When both the fallback ratio and the fallback amplitude are higher than the corresponding preset thresholds, the compression period is determined to be a continuous fall compression period.

[0071] Understandably, whether the grounding resistance remains low during the in-situ holding period is the core basis for determining whether the resistance drop at the end of the pressure period is a temporary compression or a permanent improvement in adhesion. The grounding resistance often reaches a local minimum value at the moment the pressure ends. If this local minimum value cannot be maintained after the pressure-stopping drive head stops applying pressure, then the drop during the pressure period is only formed by instantaneous compression, not by stable adhesion between the borehole soil and the outer wall of the electrode.

[0072] In one embodiment, the in-situ holding time of the continuous drop-down phase is processed. After extracting the resistance sequence within this time period from the grounding resistance sampling record, the grounding resistance value at the end of the drop phase is taken as the reference resistance. The reference resistance reflects the instantaneous conductivity between the outer wall of the rod and the soil of the borehole at the moment of pressure cessation. The resistance sequence is compared point-by-point with the reference resistance. The proportion of sampling points with resistance values ​​higher than the reference resistance out of all sampling points during this time period is counted as the rise ratio. The proportion of sampling points with resistance values ​​higher than the reference resistance in the resistance sequence is further defined as the rise ratio. The sum of the differences between the sampling points is counted as the rise amplitude; a low-level maintenance threshold is preset for determining the low-level maintenance segment. The low-level maintenance threshold includes a rise percentage threshold and a rise amplitude threshold, wherein the rise percentage threshold is preferably 0.2 to 0.3, and the rise amplitude threshold is preferably 3% to 5% of the reference resistor; if both the rise percentage and the rise amplitude are lower than the corresponding threshold in the low-level maintenance threshold, the in-situ maintenance time is determined to be a low-level maintenance segment, and the low-level maintenance segment and the continuous fall-down segment are spliced ​​along the time axis to form a verification segment.

[0073] It should be noted that the verification section only signifies that the resistance condition has been met. Whether the rod has truly penetrated the soil relative to the borehole reference surface still needs to be cross-verified using both depth and rebound data. Furthermore, for the verification section, the soil penetration depth sequence between the start and end timestamps of the section is extracted from the soil penetration depth record. The difference between the end reading and the start reading of the soil penetration depth sequence is used to obtain the net soil penetration increment. This net soil penetration increment reflects the actual downward distance of the rod relative to the borehole reference surface within this pressure cessation window.

[0074] For example, the rebound value of the verification section during the pressure-stopping period is read from the rebound displacement of the rod body. The rebound value is the displacement difference between the upward peak sampling point and the rebound end sampling point in the axial rebound trajectory. The larger the rebound value, the more significant the rebound amplitude of the rod body after pressure-stopping.

[0075] In one possible implementation, the net penetration increment is compared with the rebound value. If the penetration depth sequence increases continuously along the time axis and the net penetration increment is greater than the rebound value, then the condition that the rebound after pressure cessation does not offset the net penetration increment of this window is met. The verification section is marked as a valid penetration interval if the resistance condition, depth condition, and rebound condition are met simultaneously. If the net penetration increment is less than or equal to the rebound value, then the verification section is considered a pseudo-net penetration section and is removed from the list of valid penetration intervals.

[0076] For example, within a single compaction window of a gravel backfill section, if the net soil penetration increment is 45 mm and the rebound value is 12 mm, all three conditions are met simultaneously, and the corresponding section is marked as a valid penetration interval. However, in another window, if the net soil penetration increment is 18 mm and the rebound value is 20 mm, this window is removed from the list of valid penetration intervals but retained as a verification section. Subsequently, the net soil penetration increment and rebound value of the verification section are used as input features and imported into a support vector machine classification algorithm for secondary judgment. If the algorithm outputs an anomaly probability greater than 0.75, the verification section is identified as a pseudo-net penetration section and permanently removed. If the anomaly probability is less than or equal to 0.75, it is marked as a compensation section and assigned a weight of 0.5 for subsequent settlement calculations, ensuring that the identification of valid penetration intervals remains stable across various soil types and that the data processing logic is consistent.

[0077] S104. In the burial depth determination criteria, compare the effective penetration intervals and identify construction sections where the rebound displacement of the rod after pressure is greater than the pressure stroke increment in this window, the rod tip does not form a net penetration depth increase, and the grounding resistance remains flat or rises. These sections are identified as gravel top support interference sections and removed from the burial depth determination criteria to form the true penetration determination result after eliminating gravel top support interference.

[0078] After deducting the construction sections marked as valid penetration intervals from the burial depth determination criteria, the remaining construction sections are summarized as sections to be verified. For each pressure-stopping window in the sections to be verified, the grounding resistance curve, the soil penetration depth sequence, and the rebound displacement sequence are extracted from the grounding resistance sampling record, the soil penetration depth record, and the rod rebound displacement, respectively. For each pressure-stopping window, the difference between the first and last values ​​of the soil penetration depth sequence during the pressure duration is taken as the pressure stroke increment for this window, and the difference between the first and last values ​​at the start and end of the pressure-stopping window is taken as the net soil penetration increment for this window. The difference between the first and last values ​​of the grounding resistance curve at the start and end of the same pressure-stopping window is taken as the final state change of resistance. The rebound displacement sequence is input into an extreme value search algorithm, which outputs the maximum displacement value within the pressure-stopping window. The maximum displacement value is subtracted from the initial displacement value at the start of the pressure-stopping window to obtain the rebound value. If the rebound value is greater than the pressure stroke increment for this window, the net soil penetration increment for this window is not greater than zero, and the final state change of resistance is not less than zero, then it is determined to be a suspected top-support window. The sub-segments in the section to be verified where the suspected top support window appears consecutively are determined to be gravel top support interference sections. The gravel top support interference sections are removed from the burial depth determination criteria, and the remaining construction sections after removal are summarized as the actual penetration determination results.

[0079] It should be noted that during the downward pressing of the vertical grounding electrode, the backfill material in the borehole often contains gravel or residual pebbles with larger particle sizes. Once the rod tip hits such hard obstacles when penetrating downwards, the downward pressure continuously applied by the pressure-stopping drive head cannot be converted into the actual displacement of the rod body relative to the borehole reference plane. Although the upper section of the rod body exhibits a certain degree of elastic compression under hydraulic drive, the rod tip remains stationary. This phenomenon is called gravel top-support interference.

[0080] It is understandable that the gravel-supported interference section is misleading in the burial depth determination criteria. Its external manifestation is similar to the weakened adhesion between the electrode outer wall and the borehole wall soil: the grounding resistance does not continuously decrease during the pressure period, and there is no obvious net ingress in the depth record. However, the causes are completely different. The weakened adhesion is due to the deterioration of the conductive path between the electrode outer wall and the borehole wall, while the gravel-supported interference is due to the rod tip touching a hard obstacle. If the two are not distinguished, the subsequent pressure adjustment will generate commands in opposite directions. In one embodiment, the construction sections marked as effective penetration intervals in the burial depth determination criteria are deducted, and the remaining construction sections are summarized as sections to be verified. For each pressure-stopping window in the sections to be verified, the grounding resistance curve, penetration depth sequence, and rebound value between the start and end times of the pressure-stopping window are extracted from the grounding resistance sampling record, the soil penetration depth record, and the rod rebound displacement, respectively. The three data sources share the same timestamp.

[0081] Specifically, the incremental pressure stroke in this window is the difference between the beginning and end of the penetration depth sequence within the pressure duration. The pressure duration is the time period from when the pressure-stopping drive head begins to apply pressure to when it stops applying pressure. The incremental pressure stroke in this window reflects the displacement of the rod tip during this period. Furthermore, the net penetration increment in this window is the difference between the beginning and end of the penetration depth sequence at the start and end of the pressure-stopping window, i.e., the net change in displacement encompassing the entire process of the pressure duration and the in-situ holding time. Its physical meaning is the final downward distance of the rod tip relative to the borehole reference plane at the end of the pressure-stopping window.

[0082] It should be noted that the incremental stroke of the downward pressure in this window and the net soil penetration increment in this window are nearly equal under normal penetration conditions, differing only by a slight rebound of the rod. When the rebound displacement of the rod increases abnormally, reaching or even exceeding the incremental stroke of the downward pressure in this window, the rebound amplitude of the rod after pressure is stopped offsets all the net displacement increase obtained during the pressure period.

[0083] In one possible implementation, the final change in resistance is measured by the difference between the beginning and end of the grounding resistance curve at the start and end of the voltage-stopping window. If the difference is greater than or equal to zero, it indicates that the grounding resistance is flat or increased at the end of the voltage-stopping window compared to the beginning. Combined with the fact that the pole tip does not form a net increase in soil penetration, it can be determined that the small fluctuation in the grounding resistance of this window does not come from the improved adhesion between the electrode and the soil, but from the instability of the current path under the point contact state between the pole tip and the gravel.

[0084] For example, three conditions are simultaneously compared for each pressure-stopping window. The first condition is to determine whether the rebound value is greater than a rebound threshold. To accommodate measurement errors, this rebound threshold is preferably 1.0 to 1.2 times the pressure stroke increment. The second condition is to determine whether the net soil penetration increment is less than or equal to a net soil penetration threshold, which is 0 or a very small positive value slightly greater than 0, for example, 0.5 mm. The third condition is to determine whether the final change in resistance is less than or equal to a resistance change threshold, which is 0 or a very small negative value slightly less than 0, for example, -0.05 ohms. When all three conditions are met simultaneously, the pressure-stopping window is determined to be a suspected top-support window.

[0085] In one embodiment, the occurrence of gravel top-support interference is usually continuous. Once the rod tip touches the gravel, multiple consecutive pressure-stopping windows will all exhibit the same characteristics. Therefore, the suspected top-support windows in the section to be verified are continuously judged. The sub-segment in which the suspected top-support windows appear continuously for no less than a preset number threshold is determined as a gravel top-support interference section. The preset number threshold is 2 or 3. The gravel top-support interference section is removed from the burial depth determination criteria. The remaining construction sections after the burial depth determination criteria are removed are summarized as the actual penetration determination results.

[0086] For example, in a single pressing window sequence in a gravel backfill section, the rebound values ​​of the three consecutive pressing stops are 25 mm, 22 mm, and 28 mm, respectively. The corresponding pressing stroke increments for this window are 20 mm, 19 mm, and 24 mm, respectively. The net soil penetration increments for this window are -3 mm, -4 mm, and 0 mm, respectively. The final resistance changes are 0.03 ohms, 0.05 ohms, and 0.02 ohms, respectively. If all three conditions are met simultaneously, this sub-segment is identified as a gravel top-support interference zone and is removed from the burial depth determination criteria. The remaining construction sections are then summarized to form the actual penetration determination results, making the assessment that the adhesion between the outer wall of the electrode and the soil of the borehole wall is weakened more closely related to the actual penetration state.

[0087] S105. Integrate the actual penetration judgment results, rod rebound displacement and grounding resistance sampling records to form a penetration state record. Generate a driving force adjustment signal based on the penetration state record. The driving force adjustment signal includes a downshift boost adjustment signal and an upshift voltage stabilization adjustment signal.

[0088] The actual penetration determination result, the rod rebound displacement, and the grounding resistance sampling record are paired with the same timestamp. Three types of entries are registered under each pressure-stopping window: the first type of entry records whether the current pressure-stopping window is included in the valid penetration interval of the actual penetration determination result; the second type of entry records the rebound value of the rod rebound displacement corresponding to the current pressure-stopping window; and the third type of entry takes the difference between the values ​​of the grounding resistance sampling record at the start and end times of the current pressure-stopping window as the final state change of the resistance. The three types of entries are connected in series in chronological order to form a penetration state record. For each pressure-stopping window entry in the penetration state record, it is checked whether the pressure-stopping window falls within the effective penetration range. If the pressure-stopping window does not fall within the effective penetration range, the rebound value exceeds the preset rebound threshold, and the final change in resistance is not less than zero, a downshift boost adjustment signal is output. If the pressure-stopping window has fallen within the effective penetration range and the final change in resistance is less than zero, a upshift stabilization adjustment signal is output. The downshift boost adjustment signal and the upshift stabilization adjustment signal are combined into a driving force adjustment signal.

[0089] It should be noted that the penetration status record is a structured registration of multi-source data within the pressure-stopping window. The actual penetration judgment result, the rod rebound displacement, and the grounding resistance sampling record were originally independent, and their separate registration could not directly support the bidirectional adjustment of the pressure level. In one embodiment, the start timestamp of the pressure-stopping window is used as the primary key to pair the three data sources: the actual penetration judgment result, the rod rebound displacement, and the grounding resistance sampling record. Three types of entries are registered under each pressure-stopping window: the first type of entry is Boolean, recording whether the current pressure-stopping window is included in the effective penetration interval; if included, it is marked as 1, otherwise it is marked as 0; the second type of entry is numerical, recording the rebound value of the rod rebound displacement within the current pressure-stopping window, in millimeters; the third type of entry is a signed numerical, taking the difference between the values ​​of the grounding resistance sampling records at the start and end times of the current pressure-stopping window as the final state change of resistance, in ohms. A positive value indicates that the resistance is higher at the end of the window than at the beginning, and a negative value indicates that the resistance has decreased.

[0090] Specifically, the penetration status record is a series of three types of entries corresponding to each pressure-stopping window along the time axis, with a clear record structure that can be indexed one by one.

[0091] Preferably, the rebound threshold is pre-calibrated based on the rated stroke of the pressure-stopping drive head. For example, when the single pressure step of the pressure-stopping drive head is 40 mm, the rebound threshold is preferably 60% to 80% of the pressure step, i.e., 24 mm to 32 mm.

[0092] Understandably, the downshift boost adjustment signal targets the pressure-stopping window where the rod is not pressed down fully and the adhesion between the outer wall of the electrode and the soil in the borehole is not improved. Its physical meaning is to reduce the downshift speed gear while increasing the hydraulic output pressure, so as to penetrate the weakened adhesion section with a smaller advance step and a larger axial thrust.

[0093] In one embodiment, for each pressure-stopping window entry in the penetration state record, the value of the first type of entry is checked. If the first type of entry is 0 and the rebound value exceeds a preset rebound threshold, and the final resistance change is not less than zero, then the pressure-stopping window is determined to be a window where penetration is ineffective, rebound exceeds the limit, and resistance has not improved. A corresponding downshifting and boosting adjustment signal is output. Further, the upshifting and stabilizing adjustment signal targets a pressure-stopping window where stable penetration has been achieved and the grounding resistance is decreasing. Its physical meaning is to moderately increase the downshifting speed while maintaining the current value of the hydraulic output pressure, avoiding repeated pressure disturbances that could cause the already formed electrode outer wall to adhere to the borehole soil.

[0094] For example, for each voltage-stopping window entry in the penetration state record, if the first type of entry is 1 and the final state change of the resistance is less than zero, then the voltage-stopping window is determined to be a window that has fallen into the effective penetration range and the grounding resistance continues to decrease, and a corresponding up-level voltage regulation signal is output.

[0095] Specifically, the downshift boost adjustment signal and the upshift stabilization adjustment signal are combined to form a driving force adjustment signal. The driving force adjustment signal is sent to the hydraulic controller of the pressure-stopping drive head in the form of a command frame. The hydraulic controller switches the relief valve pressure setting value and the proportional valve flow setting value accordingly. If the relief valve pressure setting value is increased, the hydraulic output pressure will increase accordingly. If the proportional valve flow setting value is decreased, the downshift speed gear will decrease accordingly. Conversely, the pressure will be maintained and the speed will be increased.

[0096] For example, in the third pressure-stopping window of the gravel backfilling section, the first type of entry is 0, the rebound value is 30 mm exceeding the rebound threshold of 24 mm, and the final resistance change is 0.04 ohms, corresponding to the output of a downshifting pressure-boosting adjustment signal; while in the sixth pressure-stopping window of the clay backfilling section, the first type of entry is 1, and the final resistance change is -0.12 ohms, corresponding to the output of a upshifting pressure-stabilizing adjustment signal. The driving force adjustment signal is dynamically switched according to the entry content as the pressure-stopping window progresses.

[0097] S106. The driving force adjustment signal is used to update the pressing speed level. The sampling process in the pressure stop window is re-executed according to the updated speed level. The electrode adhesion is confirmed to be stable based on the construction performance of the grounding resistance curve falling back and the effective penetration interval continuing, and the final penetration identification is completed.

[0098] The driving force adjustment signal is used to update the pressing speed level of the pressure-stopping drive head. If it is a downshifting and boosting adjustment signal, the pressing speed level is lowered by one level and the hydraulic output pressure is increased by a preset amplitude. If it is a upshifting and stabilizing adjustment signal, the pressing speed level is increased by one level and the hydraulic output pressure is maintained at the current value. The pressure-stopping drive head is driven into the retesting pressure-stopping window according to the updated pressing speed level and hydraulic output pressure. The resistance sampling probe and the displacement sensor re-collect data within the retesting pressure-stopping window to obtain the retesting pressing stroke, retesting holding time, retesting rebound trajectory, and retesting grounding resistance curve. The difference between the first and last values ​​of the retesting grounding resistance curve is taken as the resistance drop amplitude. The retesting pressure-stopping window is verified according to three conditions: resistance drop during pressing, low position maintenance, and rebound not offset. If the resistance drop amplitude is higher than the preset stable drop threshold and the retesting pressure-stopping window continuously meets the three conditions and extends the effective penetration interval, it is marked as the final penetration identification result.

[0099] It should be noted that during the grounding electrode pressing operation, the pressing speed level and the hydraulic output pressure jointly determine the instantaneous pushing capability of the pressure-stopping drive head onto the rod. Simply relying on the output signal recorded in the penetration state is insufficient to change the penetration situation; a new pressing and in-situ holding process must be driven by the actual switching of the speed and pressure to achieve a closed-loop confirmation of the adhesion between the electrode outer wall and the borehole soil. In one embodiment, the driving force adjustment signal is sent to the hydraulic controller of the pressure-stopping drive head in the form of a command frame. The hydraulic controller internally maintains a mapping table of pressing speed levels and proportional valve flow setting values. The pressing speed levels are preferably divided into 1 to 5 levels, each corresponding to a proportional valve flow setting value. When the driving force adjustment signal is the down-speed boosting adjustment signal, the hydraulic controller lowers the pressing speed level by one level and independently increases the relief valve pressure setting value by 3 to 8 MPa according to a preset amplitude. When the driving force adjustment signal is the upshift pressure regulation signal, the hydraulic controller will increase the downshift speed gear by one level, and the relief valve pressure setting value will remain at the current value.

[0100] It is understood that the preset amplitude is dynamically calculated based on the current soil resistance. Specifically, the calculation method for the preset amplitude is as follows:

[0101] The ratio of the hydraulic output pressure of the pressure-stopping drive head to the increment of the rod's downward stroke within the current pressure-stopping window is obtained as the current penetration resistance gradient. The penetration resistance gradient is multiplied by a preset safety margin coefficient, which is between 1.2 and 1.5, and then multiplied by the effective working area of ​​the hydraulic cylinder corresponding to the current downward pressure speed setting. The preset amplitude of the hydraulic output pressure that needs to be increased is calculated to ensure that the increased thrust can overcome the current soil resistance without causing the rod to yield and fail.

[0102] Furthermore, the pressure-stopping drive head is driven into the retest pressure-stopping window according to the updated pressure-down speed setting and hydraulic output pressure. This retest pressure-stopping window is structurally identical to the previous one but with switched parameters. The resistance sampling probe and the displacement sensor synchronously re-acquire data within this window, obtaining the retest pressure-down stroke, retest holding time, retest rebound trajectory, and retest grounding resistance curve. These four types of retest data are archived aligned with their timestamps. After archiving, the system directly assigns the retest holding time as the in-situ holding time required for subsequent verification, extracts the maximum displacement reverse change from the retest rebound trajectory as the rebound value required for subsequent verification, and uses the retest pressure-down stroke as the net soil penetration increment required for this window for subsequent verification. This ensures that the retest parameters are effectively correlated and applied in subsequent verification conditions.

[0103] Specifically, the difference between the first and last values ​​of the retested grounding resistance curve at the start and end of the retested voltage stop window is taken. The larger the absolute value of the difference, the more significant the resistance drop. The resistance drop amplitude is the absolute value of this difference. The stable drop threshold is pre-calibrated based on the starting resistance value of the retested voltage stop window, preferably 8% to 12% of the starting resistance value of the retested voltage stop window.

[0104] In one embodiment, the retesting pressure cessation window is verified under three conditions: resistance decline during the pressure period, low in-situ maintenance, and rebound not offset. These three conditions correspond to the grounding resistance continuously declining during the pressure duration, the grounding resistance remaining low or continuing to decline during the in-situ maintenance period, and the rebound value after pressure cessation being less than the net soil penetration increment of this window. If the resistance decline amplitude is higher than the stable decline threshold and the retesting pressure cessation window meets the three conditions 2 to 3 times consecutively, it is considered that the effective penetration interval continues, and the adhesion state between the outer wall of the electrode and the soil of the borehole wall is confirmed to be stable.

[0105] For example, within a single pressure-stopping window of the gravel backfill section, the resistance drop is 0.18 ohms and the initial resistance is 1.6 ohms. The resistance drop is 11.25% of the initial resistance, which is higher than a preset stable drop threshold (e.g., 10%). The pressure-stopping window and its two adjacent pressure-stopping windows simultaneously meet all three conditions. The three windows form a continuous segment of the effective penetration interval, and the pressure-stopping window is marked as the final penetration identification result.

[0106] For example, during the retesting process in the clay backfill section, after the driving force adjustment signal undergoes two down-level and up-level switching, the resistance drop amplitude gradually increases from 0.05 ohms to 0.22 ohms. The retesting pressure stop window meets three conditions three times in a row, the adhesion state between the outer wall of the electrode and the soil of the borehole wall is determined to be stable, and the final penetration identification result is registered before the pressure stop drive head enters the next depth operation, so that the actual penetration depth of the vertical grounding electrode and the downward trend of the grounding resistance correspond to each other as the retesting pressure stop window advances.

[0107] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for driving and controlling the burial depth of vertical grounding electrodes in a power distribution network, characterized in that, The method includes: The rod's downward stroke, in-situ holding time, axial rebound trajectory, and grounding resistance curve are simultaneously collected within the pressure-stopping window using a pressure-stopping drive head and a resistance sampling probe, resulting in soil penetration depth records, grounding resistance sampling records, and rod rebound displacement. Based on the grounding resistance sampling records and soil penetration depth records, construction sections where the grounding resistance continues to rise while the depth is still increasing are extracted as the basis for determining the burial depth. Based on the burial depth determination criteria, soil penetration depth records, grounding resistance sampling records, and pole rebound displacement, the construction sections with grounding resistance continuously decreasing with the pressing stroke, remaining low during the in-situ holding period, and continuously increasing soil penetration depth, and whose rebound after stopping pressing did not offset the net soil penetration increment of this window, were extracted and marked as effective penetration sections. By comparing the effective penetration interval in the burial depth determination criteria, the construction section that is identified as a gravel top support interference section is determined and eliminated, and the actual penetration determination result is formed. The actual penetration determination results, rod rebound displacement and grounding resistance sampling records are integrated to form a penetration status record. Based on the penetration status record, a driving force adjustment signal is generated, which includes a downshift boost adjustment signal and an upshift voltage stabilization adjustment signal. The driving force adjustment signal is used to update the pressure speed level. The sampling process within the pressure stop window is re-executed according to the updated speed level. The final penetration identification is completed based on the fall of the ground resistance curve and the continuation of the effective penetration interval.

2. The method for driving and controlling the burial depth of vertical grounding electrodes in a distribution network according to claim 1, characterized in that, The method involves synchronously collecting data on the rod's downward stroke, in-situ holding time, axial rebound trajectory, and grounding resistance curve within the pressure-stopping window using a pressure-stopping drive head and a resistance sampling probe. This yields records of the soil penetration depth, grounding resistance sampling, and rod rebound displacement, including: The pressure-stopping window is opened according to the preset sampling cycle. The displacement sensor records the displacement sequence of the rod relative to the borehole reference plane point by point and the in-situ holding state is included in the soil penetration depth record. The resistance sampling probe continuously samples the grounding resistance, and the samples are then filtered by the sliding median and archived as the grounding resistance sampling record. The displacement difference between the peak upward sampling point of the axial rebound trajectory and the end sampling point of the rebound is taken as the rebound displacement of the rod.

3. The method for driving and controlling the burial depth of vertical grounding electrodes in a distribution network according to claim 1, characterized in that, The method of extracting construction sections where the grounding resistance is continuously rising and the burial depth is still increasing, based on grounding resistance sampling records and burial depth records, as the basis for determining burial depth includes: The grounding resistance sampling records are paired point by point with the soil penetration depth records according to the timestamp, and continuous sampling segments in which the resistance difference is continuously positive and higher than the resistance rise threshold, and the depth difference is also positive are extracted. The ratio of the cumulative increase in resistance to the cumulative increase in burial depth within the continuous sampling segment is taken, and the segment whose ratio is continuously higher than the fit threshold is marked as the basis for determining the burial depth.

4. The method for driving and controlling the burial depth of vertical grounding electrodes in a distribution network according to claim 1, characterized in that, The construction sections that, based on the burial depth determination criteria, soil penetration depth records, grounding resistance sampling records, and pole rebound displacement, exhibiting continuously decreasing grounding resistance with the downward pressure stroke, remaining low during the in-situ holding period, continuously increasing soil penetration depth, and whose rebound after pressure cessation did not offset the net soil penetration increment within this window, are identified as effective penetration intervals. These include: For grounding resistance curves that do not fall within the burial depth determination criteria, the difference between adjacent sampling points is taken. Segments where the percentage of fallback during the down-pressure period and the fallback amplitude are both higher than a preset threshold are determined as continuous fallback down-pressure segments. When the rise of the resistance relative to the end point of the continuous falling down pressure segment is lower than a preset threshold during the in-situ holding time of the segment, it is determined to be a low-position holding segment, which is then spliced ​​with the continuous falling down pressure segment to form a verification segment. The effective penetration interval is defined as the segment within the verification section where the soil penetration depth sequence continuously increases and the net soil penetration increment is higher than the rebound value.

5. The method for driving and controlling the burial depth of vertical grounding electrodes in a distribution network according to claim 1, characterized in that, The process involves comparing the effective penetration intervals in the burial depth determination criteria, identifying construction sections where the rod rebound displacement is greater than the incremental pressure stroke within the window, the rod tip has not formed a net penetration depth, and the grounding resistance remains the same or increases. These sections are then identified as gravel-supported interference zones and eliminated, forming the true penetration determination result, including: The construction sections marked as the effective penetration intervals are deducted from the burial depth determination criteria, and the remaining construction sections are summarized as sections to be verified. For each pressure-stopping window in the section to be verified, the grounding resistance curve, the soil penetration depth sequence, and the rebound displacement sequence are extracted from the grounding resistance sampling record, the soil penetration depth record, and the pole rebound displacement, respectively. The difference between the beginning and end of the soil penetration depth sequence during the pressure duration is taken as the pressure stroke increment of this window, and the difference between the beginning and end of the pressure cessation window is taken as the net soil penetration increment of this window. The difference between the beginning and end of the grounding resistance curve at the same pressure cessation window is taken as the final state change of resistance. The rebound displacement sequence is input into the extreme value search algorithm, and the rebound value is obtained by subtracting the initial displacement value at the start time from the maximum displacement value. A window whose rebound value is greater than the incremental pressure stroke of the window, whose net soil penetration increment of the window is not greater than zero, and whose final resistance change is not less than zero is identified as a suspected top support window. The sub-segments where the suspected top support window appears consecutively are determined to be the gravel top support interference sections. After being removed, the remaining construction sections are summarized as the actual penetration determination results.

6. The method for driving and controlling the burial depth of vertical grounding electrodes in a distribution network according to claim 1, characterized in that, The integrated actual penetration determination results, rod rebound displacement, and grounding resistance sampling records form a penetration state record. Based on this record, a driving force adjustment signal is generated. This signal includes a downshift boost adjustment signal and an upshift stabilization adjustment signal, comprising: The actual penetration determination result, the rod rebound displacement, and the grounding resistance sampling record are paired with the same timestamp. Three types of entries are registered in each pressure-stopping window: the first type of entry records whether the current pressure-stopping window is included in the effective penetration interval of the actual penetration determination result; the second type of entry records the rebound value of the rod rebound displacement corresponding to the current pressure-stopping window; and the third type of entry takes the difference between the values ​​of the grounding resistance sampling record at the start and end times of the current pressure-stopping window as the final state change of the resistance. The three types of entries are connected in series in chronological order to form the penetration state record. When the pressure stop window does not fall into the effective penetration range, the rebound value exceeds the preset rebound threshold, and the final state change of the resistance is not less than zero, the corresponding downshift boost adjustment signal is output. When the voltage stop window falls within the effective penetration range and the final change in resistance is less than zero, the corresponding up-level voltage regulation signal is output.

7. The method for driving and controlling the burial depth of vertical grounding electrodes in a distribution network according to claim 1, characterized in that, The process involves updating the pressure speed level using a driving force adjustment signal, re-executing the sampling process within the pressure stop window according to the updated speed level, and completing the final penetration identification based on the fallback of the grounding resistance curve and the continuation of the effective penetration interval. This includes: The downshifting and boosting adjustment signal will lower the downshifting speed by one level and increase the hydraulic output pressure by a preset amplitude. The upshift and pressure regulation signal will increase the downshift speed gear by one level and maintain the current value of the hydraulic output pressure. According to the updated pressing speed gear and hydraulic output pressure, drive the pressure stop drive head to enter the retest pressure stop window, and re-collect the retest pressing stroke, retest holding time, retest rebound trajectory and retest grounding resistance curve; The difference between the first and last values ​​of the retested grounding resistance curve is taken as the resistance drop amplitude. When the resistance drop amplitude is higher than the preset stable drop threshold and the retested voltage stop window continuously meets the three conditions of resistance drop during the voltage drop period, low position maintenance in the original position, and rebound not being offset, and the effective penetration interval continues to the future, it is recorded as the final penetration identification result.

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