A full-process rotary jetting pile monitoring signal identification and self-diagnosis method based on resistivity test

Abstract

The present application relates to a kind of full-flow rotary jetting pile monitoring signal identification and self-diagnosis method based on resistivity test, comprising: collecting full loop physical quantity, according to the full loop physical quantity, the logical diagnosis of phased execution according to operation time sequence, output full pile length monitoring report and quality evaluation conclusion;Wherein, the logical diagnosis of phased execution includes: the first stage of equipment power-on self-test and hardware integrity diagnosis, the second stage of cement pure paste resistance calibration diagnosis, the third stage of hole guiding stroke stratum background scanning diagnosis, the fourth stage of pile shallow detection mode closed loop identification and the fifth stage of pile deep detection inversion logic and defect classification identification.The present application solves the problem of multiple solutions in resistivity monitoring, filters false signals through layer-by-layer progressive physical criteria, ensures the uniqueness and authenticity of inversion results, and provides reliable self-diagnosis closed loop protection for real-time quality control of concealed reinforcement engineering.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering monitoring and foundation treatment quality testing technology, and in particular to a method for identifying and self-diagnosing monitoring signals of jet grouting piles throughout the entire process based on resistivity testing. Background Technology

[0002] High-pressure jet grouting, as a highly efficient foundation treatment and reinforcement technology, is widely used in key engineering fields such as high-rise building foundation reinforcement, subway tunnel boring machine (TBM) launch reinforcement, water-stop curtain for hydraulic dams, and deep foundation pit seepage prevention due to its advantages of lightweight equipment, fast construction speed, and significant reinforcement effect. The uniformity and continuity of the characteristic dimensions of the reinforced body (such as pile diameter and wall thickness) are the most crucial indicators for measuring construction quality and directly relate to the structural safety of concealed works. However, the jet grouting pile formation process is completed within complex soil layers, exhibiting high opacity. Traditional detection methods such as excavation, core sampling, and ultrasonic methods have significant shortcomings in terms of real-time performance, quantification, and environmental adaptability. In contrast, resistivity testing-based monitoring methods have core advantages such as non-destructive testing, continuous detection along the entire pile length, and real-time quantitative inversion, making them an important technical approach for achieving quality monitoring during the construction period.

[0003] However, while resistivity monitoring holds great potential for acquiring raw signals, in actual engineering sites, monitoring systems are constantly subjected to extreme environments such as high-pressure jetting, vigorous agitation, electromagnetic interference, and the scouring effect of highly reactive cement slurry. Under these conditions, the raw electrical signals are often severely interfered with by various "non-pile diameter factors," resulting in significant signal ambiguity problems. The main unresolved identification and diagnostic challenges are as follows: (1) Problems with hardware integrity and misjudgment of dynamic leakage. During deep hole monitoring, the external cable is easily squeezed and pulled, and the drill rod insulation is easily scratched by hard soil layers. Once insulation failure or dynamic leakage occurs, the measured current will increase abnormally (resistance drops sharply), leading to the erroneous conclusion of "false expansion of pile diameter" in the inversion algorithm. Existing technology lacks a closed-loop logic for real-time identification of system open circuit, short circuit and micro leakage during dynamic measurement, making it difficult to distinguish between charge leakage and formation response.

[0004] (2) The problem of confusion between cement hydration scaling and geometric defects. Cement slurry has extremely strong chemical reactivity and easily forms a solidified scale layer on the surface of the detection electrode, causing the interfacial contact resistance to increase monotonically with monitoring time. This electrical characteristic of increased resistance is similar in signal morphology to the impedance jump caused by "local necking" of the pile. At present, the industry lacks effective identification criteria to decouple the hardware sub-health characteristics in the time domain from the geometric defect characteristics in the spatial domain, which can easily lead to false alarms of quality defects.

[0005] (3) Monitoring issues related to measurement logic failure and focusing electric field collapse. Lateral logging relies on the precise constraint of the main current by the shielded electrode. However, in actual construction, if the probe is severely eccentric and adheres to the wall, the shielding circuit is broken, or a conductive "mud bridge" is formed between the electrodes, the focusing electric field will collapse instantaneously, causing the measurement reference to completely collapse. Existing technology cannot determine in real time whether the envelope logic of the deep and shallow detection modes conforms to physical consistency during the monitoring process, resulting in the output of incorrect inversion data even when the equipment is in an abnormal state, creating serious safety hazards.

[0006] In the existing field of electrical resistivity logging, while resistivity logging technology in oil and gas exploration has seen some research in fault self-diagnosis, it cannot be directly applied to solve the unique challenges of jet grouting monitoring due to the fundamental differences in application conditions. Firstly, the activity of the environmental media differs: oil drilling fluids are stable, while jet grouting cement slurry is in a dynamic process of intense hydration and particle settling, generating chemical-kinetic coupling noise far exceeding that of oil drilling conditions. Secondly, the installation and assembly logic differs: jet grouting detection devices require frequent modular on-site tightening, which easily leads to poor contact or wire entanglement; furthermore, oil logging often uses mechanical centralizers, while physical alignment is difficult to achieve in the jet grouting environment, resulting in a more complex and variable potential field distribution.

[0007] In summary, while existing high-pressure jet grouting pile monitoring technology based on resistivity testing can achieve real-time monitoring during construction, it still lacks expertise in identifying the authenticity of raw electrical signals and self-diagnosing system health. The absence of a logical judgment system covering the entire operational sequence makes monitoring results highly susceptible to equipment failures or environmental interference, leading to multiple interpretations and misjudgments, which fails to meet the high reliability requirements of concealed engineering quality control. Therefore, there is an urgent need to develop a signal identification and self-diagnosis method that operates according to the logical sequence of "equipment self-inspection - pure slurry calibration - background scanning - near-field identification - deep verification" to ensure the authenticity and reliability of monitoring data and achieve closed-loop automatic evaluation of the quality status of concealed reinforced structures. Summary of the Invention

[0008] To address the problems existing in the prior art, the present invention aims to provide a method for identifying and self-diagnosing monitoring signals for jet grouting piles based on resistivity testing throughout the entire process. This method addresses various working conditions present at jet grouting pile construction sites, including electromagnetic interference, potential hardware scaling due to high mud activity, and insulation layer damage during deep-hole operations. By establishing an electrical signal logic judgment system covering the entire process of equipment verification, slurry calibration, background scanning, and depth and shallow detection, the method accurately identifies hardware faults, measurement deviations, and actual pile defects from the original electrical signals. This solves the problem of "data ambiguity" in resistivity monitoring and provides a true and reliable data source for subsequent quantitative inversion of pile diameter.

[0009] To achieve the above objectives, the present invention provides the following solution: A method for identifying and self-diagnosing monitoring signals of jet grouting piles throughout the entire process based on resistivity testing, comprising: Collect physical quantities of the entire loop, perform phased logical diagnosis according to the operation sequence based on the physical quantities of the entire loop, and output a full pile length monitoring report and quality evaluation conclusion; The phased logical diagnosis includes: the first phase of equipment power-on self-test and hardware integrity diagnosis; the second phase of cement slurry resistance calibration diagnosis; the third phase of ground background scanning diagnosis of the pilot hole stroke; the fourth phase of pile shallow detection mode closed-loop identification; and the fifth phase of pile deep detection inversion logic and defect classification identification.

[0010] Optionally, the device power-on self-test and hardware integrity diagnosis in the first stage include: Before the detection probe enters the pile hole and is lowered into the well, the detection probe is in a no-load state, and at the same time, it collects the first total voltage, the first total output current, and the current of each branch circuit; the current of each branch circuit includes: the first main electrode current and the first shielding electrode current; If the first total output current is lower than the micro current threshold, it is determined that there is a physical open circuit in the system. Check whether the armored cable is broken, the joint is detached, the plug-in slip ring contact fails, or the ground circuit electrode connection fails. If the first total output current exceeds the rated maximum current of the power supply, or if the first total voltage drops, it is determined that a hard short circuit has occurred inside the system. Check whether the internal precision electronic compartment has been compromised due to seal failure, resulting in slurry seepage or whether there are metal foreign objects in contact between the electrodes. If the first main electrode current or the first shield electrode current has a non-zero reading during the process of not applying the detection voltage, it is determined that the sampling circuit has zero drift, and the automatic zeroing program is executed and the strong electrical interference sources around the control box are checked. If the first total voltage is within the preset pulse amplitude, and the first total output current is within the normal standby current range of the device, and the first main electrode current and the first shield electrode current meet the zero drift calibration accuracy requirements after automatic compensation, then the system hardware link and sampling circuit are determined to be working normally.

[0011] Optionally, the second stage of cement paste resistance calibration diagnosis includes: The detection probe is completely immersed in a calibration bucket containing pure cement slurry from the construction site, and the circuit is switched to shallow detection mode, that is, the positive terminal of the power supply is connected to the main feeder and the negative terminal of the power supply is connected to the shielded bus. The slurry resistance is measured by using a local closed loop between the electrodes. If the resistance of the pure slurry is greater than the empirical conventional value, it is determined that there is an old scale layer on the surface of the detection electrode or the slurry concentration is too low. Physically clean the metal surface of the electrode or verify the water-cement ratio of the cement slurry. If the resistance of the pure slurry is less than the empirical conventional value, the calibration environment is determined to be abnormal, and the detection probe is checked to see if it is touching the metal container wall or if the construction water source is contaminated.

[0012] Optionally, the second stage of cement slurry resistance calibration diagnosis also includes: Switch the circuit path to deep detection mode, connect the slurry in the calibration bucket to the ground loop electrode through a temporary wire, and compare the ratio of the first ground loop current to the first total output current. If the difference between the two is within the preset system error threshold, it is determined that the ground return line and the remote grounding electrode link are intact. If the first ground loop current is equal to zero or lower than the first total output current, it is determined that there is an open circuit or leakage in the remote loop. If the pure slurry resistance is within a preset empirically reasonable range, and the target signal variance and the distribution ratio of shielding current to main current meet the hardware design ratio, then the measurement reference calibration is deemed valid, and the current pure slurry resistance value is taken as the pure slurry reference.

[0013] Optionally, the formation background scan diagnosis of the third stage of the borehole journey includes: During the drilling process of the jet grouting rig, the control relay group is in the deep detection state, that is, the positive terminal of the power supply is connected to the main electrode feed line and the shielded bus, so that the main electrode and the shielded electrode are in the same potential focusing emission state. The negative terminal of the power supply is connected to the ground circuit return line, and the current returns through the ground circuit electrode, thereby collecting the second total output current, the second ground circuit current, the second main electrode current and the second shielded electrode current. The leakage current operator is calculated using the second ground circuit current, the second main electrode current and the second shielding electrode current. If the ratio of the leakage current operator to the second total output current is greater than the first target value, it is determined that the system has a dynamic leakage current. Check whether the drill rod insulation is scratched or the cable sheath is damaged by pressure. If the background resistivity obtained by scanning is lower than the pure slurry reference along the depth, the background data is determined to be distorted. It is necessary to confirm whether there are metal components in the formation, whether it has entered a high-mineralization brine layer, or whether the probe has been severely eccentrically attached to the wall. If the difference between the background resistance and the pure slurry reference is less than the second target value, the strong conductive stratum is determined, and the background curve is confirmed to be valid through system self-check. If the background resistance is within a reasonable formation resistance range set with the pure slurry reference, and satisfies the global current conservation being less than the dynamic leakage deviation threshold, then the background scan data is deemed valid, and the background resistance within the entire depth range of the pile location is locked as the background reference.

[0014] Optionally, calculating the leakage current operator includes: A= ( I 0+I b)− I return; in, A For leakage current operator, I 0 represents the second main electrode current. I b is the second shielding electrode current. I return refers to the current in the second ground loop.

[0015] Optionally, the fourth stage of shallow pile detection mode closed-loop identification includes: During the monitoring process, the relay group switches to shallow detection mode, that is, the positive terminal of the power supply is connected to the main electrode feeder, and the negative terminal of the power supply is switched to the shielded bus. At the same time, the ground circuit return line is disconnected by the controlled switch. The current is sent from the main electrode and flows back directly to the adjacent shielded electrode, forming a closed loop downhole, thereby collecting the main electrode branch current, the shielded branch return current and the shallow detection resistance. If the absolute deviation between the main electrode branch current and the shielded branch return current exceeds the third target value, it is determined that a conductive mud bridge has been formed between the electrodes and the anti-stick coating on the surface of the insulating short section has failed. If the shallow detection resistance is less than the pure slurry reference, it is determined that a water seepage short circuit has occurred inside the detection probe or that a structural electrical breakdown has occurred in the insulation short section. The probe sealing connection should be checked or the damaged insulation component should be replaced. If the shallow detection resistance is greater than the pure slurry reference or equal to the background reference, it is determined that the probe does not have enough slurry coating, the jet grouting at this depth section has failed or serious hole collapse has occurred, and the grouting pressure and slurry flow rate should be verified. If the shallow probe resistance is greater than the background reference, the electrode surface resistance is determined to be too high, and the probe is cleaned. If the shallow detection resistor is stably located in the lower range of the reference interval set by the background reference and the pure slurry reference, and satisfies the condition that the branch current is less than the dynamic leakage deviation threshold, then the measurement reference is determined to be valid.

[0016] Optionally, the fifth stage of pile depth detection inversion logic and defect classification identification includes: During the monitoring process, a relay is used to switch the time-division multiplexing to return the circuit to the deep detection state, and the current flows to the ground loop electrode to obtain the deep detection resistance after being focused and squeezed. If the shallow detection resistance is greater than or equal to the deep detection resistance, it is determined that the shielding focusing function is lost, indicating that the probe may be in a severely tilted wall-attached state or that the shielding drive branch is faulty. If the shallow detection resistor and the deep detection resistor rise back to the background reference synchronously, the effective pile formation is determined to have failed, and the pressure parameters of the high-pressure jet pump are checked. If the shallow detection resistance maintains the low resistance characteristic of the grout while the deep detection resistance shows a step-like sudden increase, it is determined to be a local necking of the pile body; If the shallow detection resistor and the deep detection resistor exhibit a monotonically synchronous upward drift over time and are independent of spatial depth, it is determined that the detection electrode is continuously scaling, and the probe should be flushed. If the deep detection resistor is stably within the physical envelope range set by the shallow detection resistor and the background benchmark, and satisfies the closed-loop conservation of the total output current and the ground loop return current, then the deep detection resistor is determined to be effective. Combined with the true value of the feature locked at this depth and the background benchmark, the full pile length monitoring report and quality evaluation conclusion are obtained.

[0017] The beneficial effects of this invention are as follows: The closed-loop logic of "self-diagnosis first, then calculation": This invention eliminates false defect signals caused by hardware damage, leakage, scaling, etc. through a multi-level filtering mechanism, thus ensuring the uniqueness and authenticity of the monitoring results from the root.

[0018] The invention introduces a full-time current conservation criterion: This invention utilizes... I total and I return and I 0 and I By comparing the characteristics of electrical signals such as b, it is possible to detect in real time the problem of drill rod and cable insulation damage that is very likely to occur in concealed projects.

[0019] Solving the problem of data ambiguity: This invention achieves accurate classification of hardware fouling and engineering defects (necks) by decoupling the signal features in the time domain and depth domain, significantly reducing the false alarm rate and providing a scientific basis for real-time decision-making at the construction site. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a full-process jet grouting pile monitoring signal identification and self-diagnosis method based on resistivity testing, according to an embodiment of the present invention. Figure 2 The following is a comparison diagram of the logic principle of multimodal leakage current identification using the current conservation principle in an embodiment of the present invention; (a) is a calibration diagram of cement pure slurry resistance benchmark under shallow detection mode B; (b) is a verification diagram of remote link and grounding integrity under deep detection mode A; (c) is a schematic diagram of signal identification criteria and quantization pass criteria in the calibration stage. Figure 3 This is a schematic diagram of the abnormal state determination interval based on the physical envelope boundary of the resistance value in an embodiment of the present invention; Figure 4 The following is a comparison diagram of electrical signal characteristics for distinguishing between real pile defects and hardware scaling faults in an embodiment of the present invention; (a) is a schematic diagram of the physical field and circuit path for closed-loop identification in the shallow detection mode inside the pile; (b) is a diagram of resistance identification partition and inner closed-loop current balance verification in the shallow detection stage. Figure 5 The following are embodiments of the present invention: (a) is a schematic diagram of the dynamic physical field and circuit path for dual-mode switching during the monitoring process; (b) is a fingerprint diagram of solidified spatial domain working condition identification and defect classification within the full depth range; and (c) is a diagram of probe health and scaling characteristics identification in the monitoring time domain. Among them, 1-calibration bucket; 2-shallow detection current line; 3-deep detection shielded current line; 4-cement slurry; 5-temporary connecting wire; 6-abnormal area of ​​scale buildup on electrode surface; 7-abnormal area of ​​environmental interference; 8-detection probe; 9-rational range of cement slurry resistance based on experience; 10-relay group; 11-pipeline boundary; 12-medium inside thepipe; 13-undisturbed soil layer; 14-ground loop electrode; 15-deep detection main electrode current line; 16-abnormal area of ​​undisturbed soil resistance distortion. ; 17-Low contrast risk warning zone; 18-Normal soil resistance zone; 19-Mixed grout reinforcement range; 20-Mode switching relay logic state; 21-Probe internal short circuit abnormal zone; 22-Mixed grout resistance effective zone; 23-Pile formation abnormal zone; 24-Extreme resistance abnormal zone; 25-Normal pile formation zone; 26-Local necking identification zone; 27-Broken pile / unformed pile identification zone; 28-Current focusing failure identification zone; 29-Signal time domain linear drift trend. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] This embodiment discloses a method for identifying and self-diagnosing monitoring signals of a full-process jet grouting pile based on resistivity testing, belonging to the field of geotechnical engineering monitoring and foundation treatment quality testing technology. This invention monitors the physical quantities of the entire loop in real time through a ground control system, performing phased logical diagnosis according to the sequence of "equipment verification - pure slurry calibration - background scanning - near-field identification - deep verification". Its core identification method includes: the first stage identifies open circuits and short circuits through no-load current thresholds and voltage drop characteristics; the second stage identifies electrode scaling and link connectivity by comparing the empirical range of shallow probe resistance with loop conservation; the third stage identifies dynamic leakage current during drilling by using the amplitude deviation operator between the system output current and the ground loop current; the fourth stage identifies surface mud bridge short circuits and internal insulation failures by using the balance relationship between the inner closed-loop main electrode current and the shielded return current; and the fifth stage performs focused field verification using the physical envelope constraints of shallow and deep resistivity, and combines the evolution fingerprint of the signal in the time and depth domains to classify and identify local necking, pile breakage, and electrode scaling faults.

[0024] Specifically, this embodiment discloses a method for identifying and self-diagnosing monitoring signals of the entire jet grouting pile process based on resistivity testing. The method monitors the physical quantities of the entire loop in real time through a ground control system and performs the following hierarchical and phased logical diagnoses according to the operation sequence: Phase 1: Power-on self-test and hardware integrity diagnosis: Before the probe is lowered into the well, the system is stationary on the ground. The test method is as follows: turn on the DC pulse power supply to put the system in a no-load state, and collect the voltage at the power supply output terminal in real time through the ground control system. V and total output current I total and branch current I 0、 Ib .

[0025] (1) Open circuit fault identification: If I If the total current is lower than the micro-current threshold ϵ (approaching 0), it is determined that there is a physical open circuit in the system, prompting a check for whether the armored cable is broken, the joint is detached, the pluggable slip ring contact fails, or the ground circuit electrode connection fails.

[0026] (2) Hard short circuit / insulation breakdown identification: If I The total current exceeds the rated maximum current of the power supply. I max or system supply voltage V If a drop occurs, it is determined that a hard short circuit has occurred inside the system, prompting an inspection to check whether the internal precision electronic compartment has been compromised due to seal failure leading to slurry seepage or whether there are foreign metal objects in contact between the electrodes. (3) Sampling zero drift identification: If the main electrode current is not applied when the probe voltage is not applied I 0 or shielding current IIf b has a significant non-zero reading, it is determined that the sampling circuit is experiencing zero-point drift, prompting the execution of the automatic zero-adjustment program and checking for strong electrical interference sources around the control box.

[0027] (4) Passing Criteria: If the system supply voltage V The total output current is stable at the preset pulse amplitude. I The total current is within the normal standby current range of the equipment (i.e., it does not trigger the open circuit alarm threshold and is far below the short circuit warning threshold). I (max), and the current in each measured branch is... I 0、 I If, after automatic compensation, the system meets the zero-drift calibration accuracy requirements, then the system hardware link and electronic acquisition module are deemed to be functioning normally. The system passes the initial security and integrity check and is permitted to execute the subsequent cement slurry resistance calibration procedure.

[0028] Phase Two: Cement Slurry Resistance Calibration and Diagnosis The test method is as follows: The detection probe is completely immersed in a calibration bucket containing pure cement slurry from the construction site. The circuit path is switched to shallow detection mode, that is, the positive terminal of the power supply is connected to the main feed line, and the negative terminal of the power supply is connected to the shielded bus as shallow detection current line 2. The slurry resistance is measured by using the local closed loop between the electrodes, and the current and voltage values ​​under steady state are obtained for calculating the resistivity of the slurry.

[0029] (1) Identification of scale on electrode surface: If the pure slurry resistance is calculated in reverse... R If the slurry is significantly greater than the empirical value, it is determined that there may be an old scale layer on the surface of the probe electrode or the slurry concentration is too low, indicating that the metal surface of the electrode needs to be physically cleaned or the water-cement ratio of the cement slurry needs to be verified. (2) Identification of metal interference / high-salt environment: If R If the slurry is significantly less than the empirical standard value, it is determined that the calibration environment is abnormal, suggesting checking whether the probe is touching the metal container wall or whether the construction water source is contaminated by salt / seawater. (3) Remote loop connectivity verification: The system is switched to deep detection mode, and the slurry in the calibration tank is connected to the ground loop electrode via a temporary wire as the deep detection shielded current line 3. The ground loop current is compared. I return and total system output current I The ratio of the two is used to determine the integrity of the ground return line and the remote grounding electrode link. If the difference is within the preset system error threshold, the ground return line and the remote grounding electrode link are considered to be intact; otherwise... I return ≈ 0 or significantly lower I The total value indicates a need to check for open circuits or leakage in the remote circuit.

[0030] (4) Passing Criterion: If the resistance of the pure slurry is obtained by actual measurement and calculation RThe slurry is stable within a preset, empirically reasonable range, and satisfies the requirements of minimal signal variance (e.g., <2%) and a proper distribution ratio between shielding current and main current. I b / I If the value matches the hardware design ratio, the measurement reference calibration is considered valid. The system automatically locks this value. R The slurry value serves as the physical lower limit benchmark for the full-range inversion algorithm and confirms that the surface cleanliness of the probe electrode meets the standard, allowing the system to enter the downhole scanning procedure.

[0031] Phase 3: Formation background scan diagnosis of the borehole travel: The test method is as follows: During the drilling process of the jet grouting rig's pilot hole, the control relay group is in a deep detection state, that is, the positive terminal of the power supply is connected to the main feeder and the shielded bus, so that the main electrode... A 0 and shielding electrode A 1. A '1' is in equipotential focusing emission mode, with the negative terminal of the power supply connected to the ground loop return line, and the current returns via the ground loop electrode. The system monitors in real time with depth. I total I 0、 I return and Ib .

[0032] (1) Full-stroke dynamic leakage identification: If the leakage operator ( I 0+ I b)− I return and I If the percentage of total is too large (e.g., exceeding 5%), it is determined that the system has a dynamic leakage current, prompting a check whether the drill rod insulation is scratched or the cable sheath is damaged by pressure. (2) Background resistance distortion identification: If the background resistance obtained by scanning R The soil depth frequently falls below the pure slurry reference level. R If slurry occurs, it is determined to be background data distortion, prompting confirmation of whether there are metal components in the formation, whether it has entered a high-mineralization brine layer, or whether the probe has experienced severe eccentricity and adhesion to the wall. (3) Low contrast risk identification: If R soil and R If the difference in slurry values ​​is too small (e.g., less than 20%), it is determined to be a highly conductive stratum, and an early warning is issued that the sensitivity of subsequent pile diameter inversion will decrease significantly. The effectiveness of the background curve is confirmed through system self-check.

[0033] (4) Passing Criterion: If the measured background resistance R Soil stability is in [ R A reasonable range of formation resistance within the slurry, +∞] interval (i.e., significantly higher than the pure slurry resistance benchmark), and satisfying global current conservation |(I 0+ Ib )− I return | δ If the system's allowed dynamic leakage deviation threshold is met, the background scan data is considered valid. The system records and locks the undisturbed soil background resistance curve across the entire depth range of the pile location in real time. R Soil was used as the background benchmark for subsequent inversion calculations to complete the monitoring task in this stage.

[0034] Phase 4: Closed-loop identification of shallow in-pile detection mode: The test method is as follows: During the monitoring lift, the relay group switches to shallow detection mode. The circuit path is as follows: the positive power supply is connected to the main feeder, and the negative power supply is switched to the shielded bus. Simultaneously, the ground loop return line is disconnected using a controlled switch. Current flows from the main electrode... A After being emitted, the current flows directly back to the adjacent shielding electrode. A 1. Forming a closed loop in the well.

[0035] (1) Surface mud bridge short circuit identification: If the absolute deviation between the main electrode branch current and the shielded branch return current exceeds the set threshold, it is determined that a conductive mud bridge is formed between the electrodes, causing abnormal current leakage, indicating that the anti-stick coating on the surface of the insulating short section may fail. (2) Internal short circuit identification: If the measured mud resistance R LLS is much smaller than R If slurry occurs, it indicates that there is water seepage and short circuit inside the probe or structural electrical breakdown of the insulation short section, suggesting checking the probe's sealing connection or replacing the damaged insulation component; (3) Identification of effective pile driving failure: If the measured shallow detection resistance is... R LLS is much greater than R slurry and close R If soil is detected, it indicates that there is insufficient grout around the probe, suggesting that the jet grouting at that depth section has failed or severe hole collapse has occurred. The grouting pressure and grout flow rate need to be verified. (4) Interface isolation identification: If the measured mud resistance R LLS is much greater than R If soil is detected, it indicates that the electrode surface resistance may be too high, suggesting that the probe needs to be cleaned. (5) Passing Criterion: If the measured shallow probe resistance R LLS is stable in [ R slurry, R The low-value segment within the interval [soil], and satisfying branch current conservation | I 0− I b∣< δ If the measurement reference is valid, the system will extract the shallow probe resistance at that depth. RLLS is used for subsequent diameter inversion.

[0036] Phase 5: Pile Depth Detection Inversion Logic and Defect Classification and Identification The testing method is as follows: During the monitoring process, a relay is used to switch the circuit back to deep detection mode in time division multiplexing with the fourth stage, allowing current to flow to the ground loop electrode. The system acquires the deep detection resistance data after being compressed by focusing and performs a logical comparison with the shallow detection data acquired in the fourth stage.

[0037] (1) Focusing field performance verification: If the measured shallow probe resistance R LLS is greater than or equal to the depth sensing resistance. R If LLD is detected, it indicates that the shielding focusing function has been lost, suggesting that the probe may be in a severely tilted state or that the shielding drive branch is faulty. (2) Identification of broken piles / uncompleted piles: If R LLD and R LLS synchronously rises to the stratigraphic background. R If the soil level is low, the pile driving is considered a failure and a prompt will be made to check the pressure parameters of the high-pressure jet pump. (3) Local necking identification: If R LLS maintains the low resistance characteristic of the slurry. R If LLD increases in a step-like manner, it is determined to be a localized necking of the pile body; (4) Detector accuracy identification: If R LLD and R If the LLS shows a monotonous synchronous upward drift over time and is independent of spatial depth, it is determined that the probe electrode has been continuously scaled up, indicating that the measurement accuracy has been reduced and the probe needs to be flushed.

[0038] (5) Passing Criterion: If the measured depth detection resistance is... R LLD is stable in [ R LLS, R If the data is within a reasonable physical envelope of the soil and meets the closed-loop conservation criterion of the total system output current and the ground loop return current, then the deep exploration data is considered valid. The system then calls the inversion algorithm, combines the locked feature true values ​​at that depth with the background benchmark, and calculates and outputs quantitative pile diameter monitoring results and quality evaluation conclusions in real time.

[0039] The present invention will be further described below with reference to the accompanying drawings, so that those skilled in the art can better understand the present invention.

[0040] like Figure 1As shown, this embodiment discloses a method for identifying and self-diagnosing monitoring signals of a full-process jet grouting pile based on resistivity testing. Its core actuator is a detection probe 8 integrated with a three-electrode system. This invention monitors the physical quantities of the entire loop in real time and divides the diagnostic process into five progressively advancing logic gate stages according to the operational sequence after the start node. These five stages are: Stage I: Equipment power-on self-test; Stage II: Cement slurry resistance calibration; Stage III: Formation background resistance scanning; Stage IV: Shallow pile detection mode closed-loop identification; and Stage V: Pile depth detection inversion and defect classification. The system establishes a judgment node at each stage. If the judgment result is "no," the corresponding early warning branch is triggered and summarized in the early warning output module; if the judgment result is "yes," it is allowed to proceed to the next stage, thereby ensuring the authenticity and reliability of the final output monitoring results and evaluation report.

[0041] (I) Phase I: Equipment Power-On Self-Test and Hardware Integrity Diagnosis Before the detection probe 8 is lowered into the pile hole, the system first performs Phase I in a surface air environment. During this phase, the detection probe 8 is in a no-load, unloaded state, and the total voltage output by the power supply is collected in real time by the ground control system. V Total output current I total and the current in each branch I 0、 I b In this stage, the physical connection status of the hardware link is identified using fundamental laws of electricity. The identification logic for nodes is as follows: (1) Open circuit fault (break circuit) identification: After the system is powered on, if the total output current is monitored... I total Below the microcurrent threshold ϵ If the current approaches 0, the system determines it as a "line interruption" and enters the hardware fault indication branch. Because the detection system integrates active components such as signal processing circuit boards, even if the probe is suspended in an insulating air medium, its standby power consumption will generate a small static current. If the measured total current... I total The result is almost zero, which physically proves that the current loop from the positive terminal of the power supply through the cable to the downhole electrode, or from the downhole probe back to the negative terminal of the power supply through the cable, is physically disconnected. Therefore, it suggests checking for problems such as internal core wire breakage in the external armored cable, loose lateral cable connectors, or insufficient pluggable conductive slip ring connectors between sections of the probe causing contact detachment.

[0042] (2) Hard short circuit / insulation breakdown identification: If the total output current I total Instantaneous exceed the rated maximum current of the power supply I max Or monitor the system power supply voltageV If a sharp drop occurs (such as falling below 50% of the preset pulse amplitude), the system determines it as an "internal hard short circuit" and enters a branch. According to Ohm's law... I = V / R In an air environment, the metal electrodes of the probe should be in a state of extremely high resistance. An abnormal surge in current indicates an illegal path with extremely low impedance between the positive and negative electrodes within the system. A voltage drop is caused by excessive short-circuit current triggering the power supply's load protection or causing a voltage drop at the power supply output. This phenomenon indicates physical damage to the detector, suggesting the following issues: a failure in the internal seal of the electronic compartment housing allowing conductive slurry to seep in and cause a short circuit on the circuit board; conductive foreign objects causing contact between the insulation shorts between the main electrode and the shielding electrode; or damage to the insulation layers of the core wires of different polarities in the armored cable, resulting in contact between them.

[0043] (3) Zero drift identification of sampling circuit: During the instantaneous no-load gap when no probe pulse voltage is applied, if the main electrode current... I 0 or shielding current I b If the sampled data shows a significant non-zero reading, it is considered "sampling zero drift". In environments with strong electromagnetic interference, sensors and operational amplifiers may generate bias voltages or induced electromotive forces even without signal input. This "noise floor" caused by the characteristics of electronic devices, if not eliminated, will accumulate errors in subsequent low-resistivity cement slurry environments. Therefore, the system records this bias value and performs automatic subtraction in all subsequent calculation stages to ensure the accuracy of current extraction.

[0044] If and only if the system satisfies V Stablize, ϵ ≤ I total ≪ I max When the zero drift of each branch meets the calibration accuracy requirements after software compensation, the node result is "yes". At this time, it is proven that the physical connection and sealing integrity of the detection device have initially met the standards, and the basic conditions for well operation are met. The system automatically unlocks and jumps to cement pure slurry resistance calibration stage II.

[0045] (II) Stage II: Cement Slurry Resistivity Calibration and Diagnosis: Before formal well exploration, the "electrical zero point" for this pile monitoring needs to be established through a ground calibration procedure. The test method is as follows: The detection probe 8 is completely immersed in the calibration bucket 1 containing cement slurry 4 from the construction site. The ground control system first switches the relay group 10 to shallow detection mode, forming a local closed-loop circuit between the main electrode A0 and the shielding electrode A1. Subsequently, it switches to deep detection mode and connects the slurry in the calibration bucket 1 to the ground circuit electrode 14, which is far from the pile location, through a temporary connecting wire 5, to simulate a real large-scale formation circulation circuit. The identification logic of the judgment node is as follows: (1) Electrode surface condition and scale identification: The system obtains the measured resistance in shallow detection mode. R slurry If this value is significantly greater than the upper limit of the preset empirically reasonable range of 9 for the resistance of cement paste. R max , that is Figure 2 The abnormal scale buildup area 6 on the electrode surface shown in (a)-(c) is identified by the system as "abnormal sensor contact interface". This is because cement slurry is a strong electrolyte with extremely low resistivity. In the short-path loop of shallow detection, the resistance reading is mainly controlled by the surface condition of the main electrode. If the reading is abnormally high, it reflects a high-resistance layer between the electrode metal surface and the liquid medium. This is usually because after repeated use, the electrode surface is covered with a dried cement shell or a passivated oxide film, increasing the contact resistance. Therefore, the system prompts the operator to stop the program and polish the electrode metal surface with fine sandpaper or chemical cleaning agent to remove scale; otherwise, the added value of the contact resistance will cause a serious shrinkage deviation in the subsequent diameter inversion results.

[0046] (2) Identification of metal interference / high salt environment: If the measured resistance R slurry Significantly less than the lower limit of the empirically reasonable range of 9 for the resistance of pure cement paste R min If the reading falls into the abnormal environmental interference zone 7, the system determines it as "reference signal distortion". Under a certain electrode geometry, the resistance of pure cement slurry has a physical lower limit. If the reading is extremely low, it indicates that the current has not completely diffused through the slurry medium, but has found a path with lower resistance. Therefore, the system prompts to check whether the inside of calibration bucket 1 is made of metal, or whether the detection probe 8 directly contacted the metal bucket wall during placement, causing a signal short circuit; if metal interference is ruled out, it is determined that the construction water contains excessive electrolyte ions (such as seawater intrusion, saline-alkali interference), prompting verification of the slurry mixing environment to prevent inversion failure due to loss of contrast.

[0047] (3) Remote loop connectivity verification: In deep probe mode, the system establishes a simulated loop through temporary connecting wire 5. The algorithm compares the total output current of the ground control system in real time. I total Current returned by the ground loop electrode I return If the difference between the two is Δ I Exceeding the system tolerance threshold (e.g.) I totalIf the charge exceeds 5%, it is considered a "remote link anomaly." According to Kirchhoff's current law, the total charge flowing out of the probe should be conserved with the charge of the return electrode. Since the ground loop return cable is often tens of meters long and the joints are exposed in muddy construction sites, there may be loose connections or damage. Therefore, the system prompts to check whether the cable leading to the remote ground loop electrode 14 is broken, whether the terminal is corroded or oxidized, or whether the temporary connecting wire 5 has poor contact with the slurry, to ensure that the deep exploration mode can generate sufficient focusing thrust after the official well is lowered.

[0048] (4) Verification of shielded branch drive performance: In deep probe mode, verify the shielded branch current. I b With the main branch current I The real-time ratio of 0. If this ratio deviates from the electrode system design constant by more than a certain range (e.g., 20%), it is determined that the electrode's current focusing ability has decreased. The three-sided principle relies on the potential balance between the shielding electrode and the main electrode. If I b If the value is too small, it indicates that the shielding electrode is not receiving sufficient drive. Therefore, the system prompts you to check if the equipotential bus inside the probe 8 is loose, to prevent the main current from flowing upwards and causing false pile diameter alarms.

[0049] If and only if the measured resistance R slurry The resistance of the cement slurry stabilizes within the empirically reasonable range of 9, and the current conservation deviation Δ I Within the preset range, and when the shielding current ratio is normal, the node result is determined as "yes". The system automatically locks this depth-independent node. R slurry The numerical value serves as the physical lower limit benchmark (electrical zero point) for all subsequent diameter calculations, and allows the system to enter the drilling scanning phase III.

[0050] (III) Stage III: Formation Background Resistivity Scan Diagnosis: In the dynamic dual-stroke operation described in this invention, the main task of the drilling stroke is to obtain the background parameters of the original soil strata. The testing method is as follows: During the drilling of the pilot hole (before grouting) by the jet grouting rig, the ground control system adjusts the relay group 10 to the deep detection mode, that is, the positive terminal of the power supply connects the main feeder and the shielded bus, so that the main electrode A0 and the shielded electrodes A1 and A′1 are in an equipotential focusing emission state, and the negative terminal of the power supply connects the ground loop return line to the grounding electrode. For example... Figure 3 As shown in (a), the detection probe 8 is located inside the borehole boundary 11 of a narrow wellbore filled with a borehole medium 12 (such as water or thin mud) and moves downward with the drill pipe. Current is ejected from the downhole electrode, focused vertically through the wellbore, and injected into the undisturbed soil layer 13. It then flows through the formation loop to the distal surface loop electrode 14 and back to the power source. The system operates with increasing depth. HReal-time monitoring of total output current I total Ground circuit return current I return and the current of the main and shielded branches I 0、 I b The identification logic for the decision node is as follows: (1) Dynamic leakage current identification throughout the entire stroke: Real-time calculation of dynamic leakage current operator Δ I =( I 0+ I b )− I return If this deviation accounts for a certain percentage of the total current... I total If the proportion is too high (e.g., exceeding 5%), it is judged as "system insulation integrity is damaged," and an abnormal prompt branch is entered. In deep exploration mode, all emitted current should theoretically be recovered through the surface loop electrode 14. If the sum of the currents at the transmitting end is significantly greater than the current at the transmitting end, it indicates that some current did not pass through the far-end loop of the formation, but returned directly to the power source through a leakage point in the middle. Therefore, the system prompts to check whether the armored cable has been mechanically squeezed at the wellhead, causing damage to the sheath and conduction, in order to identify energy leakage in the "non-probe area" and prevent leakage signals from being mistaken for formation feedback.

[0051] (2) Identification of background resistivity distortion anomalies: The system compares the measured background resistivity of the undisturbed soil in real time. R soil Compared with the pure slurry resistance reference obtained in Stage II R slurry .like R soil Frequently below R slurry (i.e., falling into) Figure 3 (b) The undisturbed soil resistivity distortion anomaly zone 16) is identified by the system as "background data distortion". Cement grout, as a strong electrolyte, usually constitutes the upper limit of conductivity (lower limit of resistance) under all operating conditions. In normal undisturbed soil layers, due to the insulation of the soil particle skeleton, its background resistance should theoretically be significantly higher than that of the grout. Therefore, the system prompts to confirm whether the current detection layer contains ferromagnetic components such as metal pipes, rebar cages, and sheet piles, or whether it has entered a highly mineralized saltwater layer or saline soil zone. In addition, if the probe is severely eccentrically attached to the wall, causing direct physical contact between the electrode and the borehole wall, this type of ultra-low resistance anomaly will also occur.

[0052] (3) Low contrast risk identification and early warning: If the measured background resistance R soil Compared with the benchmark value R slurryIf the numerical difference is too small (e.g., the difference fluctuates within 20%, falling into the low contrast risk warning zone 17), the system will automatically trigger an "inversion sensitivity warning". The accuracy of resistivity inversion depends on the electrical contrast between the "target object (pile)" and the "background (soil)". When the soil resistivity is naturally extremely low, the electrical characteristics of the two are very similar, causing the denominator in the subsequent calculation formula to approach zero. Therefore, the system prompts that there may be a large error or insufficient sensitivity in the pile diameter inversion during the subsequent lifting stroke. It is recommended that the construction site adjust the concentration of cement slurry to artificially increase the electrical difference based on this feedback, or add algorithm weight compensation during the data processing stage.

[0053] If the actual measured background resistance R soil Stable Figure 3 (b) shows the normal resistivity zone 18 of the undisturbed soil (i.e., significantly higher than the pure slurry reference). R slurry If the dynamic leakage current operator remains within the preset tolerance range, the node result is determined as "yes". The system automatically records and locks the undisturbed soil background resistance curve within the entire depth range of the pile location. R soil This curve will serve as the sole background benchmark for quantitative inversion of pile diameter during Stage IV, thus completing the monitoring task for the drilling phase.

[0054] (iv) Stage IV: Closed-loop identification of shallow in-pile detection mode: During the enhanced monitoring process, the system first enters the identification phase for near-field slurry properties. The testing method is as follows: the ground control system switches the relay group's mode switching relay logic state 20 to shallow detection state. At this time, the circuit path is: the positive power supply is connected to the main feeder, and the negative power supply is switched to the shielded bus. Simultaneously, the feedback path pointing to the ground loop electrode 14 is physically disconnected using a controlled switch. For example... Figure 4 As shown in (a), after the measuring current is emitted from the main electrode A0, it is attracted by the opposite charges at close range and flows directly back to the adjacent shielding electrode A1 or A′1, forming a local closed-loop circuit in the well that does not touch the original soil boundary. The system monitors in real time. I total Main electrode current I 0. Shielding return current I b and measured shallow probe resistance R LLS The identification logic for the decision node is as follows: (1) Surface mud bridge short circuit identification: Since the ground circuit has been completely cut off at this time, theoretically the current flowing out of the main electrode is I 0 should be the return current received by the shielding electrode. I b Strictly equal. If an absolute deviation between the two is detected, | I 0−I b | Exceeding the set threshold δ (i.e., falling into) Figure 4 The localized necking identification area 26 shown in the current deviation diagram indicates that the system determines it as "inner closed-loop insulation failure". In the downhole closed-loop state, if... I 0≠ I b From a physical perspective, it was proven that some current did not flow back through the pre-set slurry path, but instead leaked into the formation or drill pipe by crossing the surface of the insulating stub or through damaged cable seals. Therefore, the system indicated that a conductive "mud bridge" might have formed between the main electrode and the shielding electrode, usually due to severe scaling on the insulating stub surface or damage to the Teflon anti-stick coating. In this case, the data contains illegal current shunting, requiring a reduction in speed to flush the electrodes with fluid, or leakage compensation to be implemented in the algorithm.

[0055] (2) Identification of internal short circuit and insulation breakdown: If the measured shallow probe resistance R LLS Much smaller than the pure slurry resistance reference locked in Stage II R slurry (i.e., falling into) Figure 4 (b) The short-circuit anomaly zone 21 inside the probe shown is identified by the system as "hardware structural damage". Pure cement slurry is the conductivity limit under this condition, and the resistance of any cement-soil mixture cannot be lower than the pure slurry reference value. If the reading exceeds this lower limit, there is only one physical possibility: direct electrical contact between metals has occurred inside the probe. Therefore, the system indicates that slurry leakage inside the probe 8 has caused a short circuit, or that the insulation short section has been subjected to high voltage breakdown. At this time, the measurement reference has collapsed, and the test must be stopped immediately.

[0056] (3) Identification of effective pile formation failure (broken pile / collapsed hole): If the measured shallow resistance R LLS Significantly deviates from the low resistivity zone and approaches the formation background resistivity recorded in Stage III. R soil (i.e., falling into) Figure 4 (b) The pile formation anomaly zone 23, which is independent of the detection depth, is identified as "near-field medium anomaly". Shallow detection has a relatively small detection depth (e.g., 100mm-150mm), and its measurement space should be completely enveloped by grout. If the measured resistance value shows high resistivity characteristics of the stratum, it indicates a lack of low-resistivity grout coverage around the probe. Therefore, the system will indicate a possible serious pile breakage, jet grouting failure, or large-scale borehole collapse causing the undisturbed soil to directly compress the probe. The system will record this "grout-free zone" and issue a forced jet grouting warning.

[0057] (4) Electrode surface isolation identification: If the measured shallow detection resistance R LLSAbnormal surge, even far exceeding the background resistivity of the formation. R soil (i.e., falling into) Figure 4 (b) The extremely high resistance abnormality zone 24) is identified by the system as "electrode interface failure". When the electrode surface is covered by a dry cement shell, or when the probe is located at the center of a large compressed air bladder, the electrode is physically isolated from the conductive medium, causing the circuit impedance to tend to infinity. Therefore, the system prompts that the probe needs to be cleaned or the grouting pressure needs to be checked to prevent measurement blind spots caused by excessive air bubbles.

[0058] If the measured shallow probe resistance R LLS Stable Figure 4 (b) shows the effective resistance region 22 of the mixed slurry (i.e., between) R slurry and R soil (the low value range between), and satisfies the inner closed-loop current conservation | I 0− I b ∣< δ If the result is "yes", the node is determined to be "yes". The system extracts the shallow probe resistance at that depth. R LLS As a calculation parameter for the resistivity of the mixed slurry at this cross section, the slurry signal is accurately stripped.

[0059] (V) Stage V: Pile depth detection inversion logic and defect classification and identification: During the monitoring process, the system uses a relay group mode switching relay logic state 20 and stage IV to perform millisecond-level time-division multiplexing switching, returning the circuit to the deep exploration state. The test method is as follows: the positive terminal of the power supply is simultaneously connected to the main feeder and the shielded bus, ensuring that the downhole main electrode A0 and the shielded electrodes A1 and A′1 are in an equipotential emission state; the negative terminal of the power supply is connected back to the surface loop transmission line. For example... Figure 5 As shown in (a), the measuring current of the deep-penetration main electrode current line 15, under the lateral compression of the shielding current of the deep-penetration shielding current line 3, vertically passes through the slurry area (mixed slurry reinforcement range 19) and is injected into the undisturbed soil layer 13. The system acquires the measured resistance of the deep-penetration in real time. R LLD And combined with the shallow probe resistance already locked in stage IV R LLS Stratigraphic background of Stage III record R soil The final logic verification and defect identification are performed by determining the node: (1) Focused field performance verification and attitude anomaly identification: The system compares the impedance magnitudes of deep and shallow modes in real time. If the measured values ​​meet R... LLS ≥R LLD (i.e., falling into) Figure 5 (b) The current focusing failure identification zone 28 shown indicates "electric field focusing function failure". This is because, according to the lateral logging physical model, the current path in deep exploration mode includes high-resistivity undisturbed soil, and its total resistance is theoretically greater than that in shallow exploration mode, which only explores low-resistivity slurry areas. Therefore, the system indicates that the shielded electrode drive branch may be open-circuited, or that probe 8 is severely tilted and in close contact with the high-resistivity soil on the borehole wall, causing the focusing electric field to collapse violently. At this time, the basic assumptions of the inversion formula are no longer satisfied, and the data at the current depth is marked as invalid.

[0060] (2) Identification of effective pile failure (broken pile): If a pile failure is detected at a certain depth R LLD and R LLS Synchronous recovery to formation background resistivity R soil Horizontal (i.e., falling into) Figure 5 (b) shows the broken pile / uncompleted pile identification area 27). This feature indicates that the induced dielectric properties, whether in the deep electric field or the near-field electric field, are completely consistent with the undisturbed soil at the time of drilling, indicating that there is no low-resistivity cement slurry surrounding the probe. Therefore, the system indicates that this depth section may have "effective pile formation failure". This is usually caused by a sudden stop of the high-pressure jet pump, nozzle blockage, or complete pile breakage due to severe necking.

[0061] (3) Precise identification of local necking defects: shallow detection resistance R LLS Maintain stable fluctuations within the low resistivity range of the slurry, while deep probe resistance R LLD A significant step-like surge occurs at a specific depth (i.e., upon entering...). Figure 5 (b) shows the localized necking identification area 26. R LLS The stability demonstrates that there is an adequate supply of slurry around the probe and that the electrodes are free of scale. R LLD The sudden jump reflects the approach of the high-resistivity soil boundary to the probe side due to pile diameter shrinkage. Therefore, the system identifies it as a localized necking defect. At this point, the system automatically locks the electrical signal at that depth and calls the corresponding algorithm to convert the impedance increment into a precise diameter reduction value.

[0062] (4) Detector status (scale) identification: such as Figure 5 As shown in (c), if R LLD and R LLS The two curves show a relationship with the detection depth throughout the entire pile travel. H It is irrelevant, but it varies with monitoring time.t The signal exhibits a monotonically, synchronously, and linearly increasing trend with linear drift in the time domain.29. Cement hydration and hardening have a cumulative effect over time. As the electrode surface gradually becomes covered with a hard cement shell, the contact resistance increases globally. This "time domain shift" has distinctly different waveform characteristics from "spatial domain necking." Therefore, the system determines that the probe electrode may be scaled, indicating that the measurement accuracy of the current data is continuously decreasing due to surface scaling. The system recommends lifting the probe for physical descaling.

[0063] If the actual measured depth detection resistance R LLD Stable in [ R LLS , R soil Within this reasonable physical envelope interval (such as...) Figure 5 (b) shows the normal pile-forming zone 25), and satisfies the total output current of the system. I total Current returning to ground circuit I return If the closed-loop conservation criterion is met, the result of the node is determined to be "yes". The system determines that the current data source is real, reliable and free from hardware fault interference, and then calls the pile diameter inversion algorithm to output a full-length monitoring report and quality evaluation conclusion including "pile diameter, irregular envelope zone and defect level distribution".

[0064] This invention provides a highly self-regulating quality monitoring solution for concealed high-pressure jet grouting projects by constructing a five-stage logic gate diagnostic system covering "ground self-inspection - pure slurry calibration - background scanning - near-field stripping - deep verification". The core advancement of this method lies in its ability to accurately identify interference signals from "pseudo-defects" such as electrode scaling, system leakage, and probe adhesion during the testing process, utilizing the principle of charge conservation and the physical envelope constraint of resistance. This solves the long-standing problem of signal ambiguity in resistivity monitoring. The system not only ensures the accuracy and uniqueness of the inverted pile diameter values ​​but also, due to its ability to detect broken piles and necking before the slurry initially sets and guide immediate re-grouting, avoids blind spots in quality control from the source. This represents a technological leap from "passive post-event detection" to "active process diagnosis," possessing significant engineering application value.

[0065] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. For example, using a deep learning model based on a convolutional neural network (CNN) or a recurrent neural network (RNN) to replace the aforementioned logic gate algorithm to identify the characteristic fingerprints of electrode scaling or necking, or adjusting the number of electrode systems for large-diameter pile foundations to form redundant cross-connections for multi-layered depth and shallow detection, or integrating this identification logic into a handheld mobile terminal or a remote digital construction site cloud platform, etc. These improvements and modifications based on the core method of "phased signal identification and hierarchical logic self-diagnosis" and equivalent electrical and physical laws of the present invention should all fall within the protection scope of the present invention.

Claims

1. A method for identifying and self-diagnosing monitoring signals of a full-process jet grouting pile based on resistivity testing, characterized in that, include: Collect physical quantities of the entire loop, perform phased logical diagnosis according to the operation sequence based on the physical quantities of the entire loop, and output a full pile length monitoring report and quality evaluation conclusion; The phased logical diagnosis includes: the first phase of equipment power-on self-test and hardware integrity diagnosis; the second phase of cement slurry resistance calibration diagnosis; the third phase of ground background scanning diagnosis of the pilot hole stroke; the fourth phase of pile shallow detection mode closed-loop identification; and the fifth phase of pile deep detection inversion logic and defect classification identification.

2. The method for identifying and self-diagnosing monitoring signals of the entire jet grouting pile process based on resistivity testing according to claim 1, characterized in that, The first phase of device power-on self-test and hardware integrity diagnosis includes: Before the detection probe enters the pile hole and is lowered into the well, the detection probe is in a no-load state, and at the same time, it collects the first total voltage, the first total output current, and the current of each branch circuit; the current of each branch circuit includes: the first main electrode current and the first shielding electrode current; If the first total output current is lower than the micro current threshold, it is determined that there is a physical open circuit in the system. Check whether the armored cable is broken, the joint is detached, the plug-in slip ring contact fails, or the ground circuit electrode connection fails. If the first total output current exceeds the rated maximum current of the power supply, or if the first total voltage drops, it is determined that a hard short circuit has occurred inside the system. Check whether the internal precision electronic compartment has been compromised due to seal failure, resulting in slurry seepage or whether there are metal foreign objects in contact between the electrodes. If the first main electrode current or the first shield electrode current has a non-zero reading during the process of not applying the detection voltage, it is determined that the sampling circuit has zero drift, and the automatic zeroing program is executed and the strong electrical interference sources around the control box are checked. If the first total voltage is within the preset pulse amplitude, and the first total output current is within the normal standby current range of the device, and the first main electrode current and the first shield electrode current meet the zero drift calibration accuracy requirements after automatic compensation, then the system hardware link and sampling circuit are determined to be working normally.

3. The method for identifying and self-diagnosing monitoring signals of the entire jet grouting pile process based on resistivity testing according to claim 1, characterized in that, The second stage of cement slurry resistance calibration diagnosis includes: The detection probe is completely immersed in a calibration bucket containing pure cement slurry from the construction site, and the circuit is switched to shallow detection mode, that is, the positive terminal of the power supply is connected to the main feeder and the negative terminal of the power supply is connected to the shielded bus. The slurry resistance is measured by using a local closed loop between the electrodes. If the resistance of the pure slurry is greater than the empirical conventional value, it is determined that there is an old scale layer on the surface of the detection electrode or the slurry concentration is too low. Physically clean the metal surface of the electrode or verify the water-cement ratio of the cement slurry. If the resistance of the pure slurry is less than the empirical conventional value, the calibration environment is determined to be abnormal, and the detection probe is checked to see if it is touching the metal container wall or if the construction water source is contaminated.

4. The method for identifying and self-diagnosing monitoring signals of the entire jet grouting pile based on resistivity testing according to claim 3, characterized in that, The second stage of cement slurry resistance calibration diagnosis also includes: Switch the circuit path to deep detection mode, connect the slurry in the calibration bucket to the ground loop electrode through a temporary wire, and compare the ratio of the first ground loop current to the first total output current. If the difference between the two is within the preset system error threshold, it is determined that the ground return line and the remote grounding electrode link are intact. If the first ground loop current is equal to zero or lower than the first total output current, it is determined that there is an open circuit or leakage in the remote loop. If the pure slurry resistance is within a preset empirically reasonable range, and the target signal variance and the distribution ratio of shielding current to main current meet the hardware design ratio, then the measurement reference calibration is deemed valid, and the current pure slurry resistance value is taken as the pure slurry reference.

5. The method for identifying and self-diagnosing monitoring signals of the entire jet grouting pile process based on resistivity testing according to claim 1, characterized in that, The formation background scan diagnosis of the third stage of the borehole journey includes: During the drilling process of the jet grouting rig, the control relay group is in the deep detection state, that is, the positive terminal of the power supply is connected to the main electrode feed line and the shielded bus, so that the main electrode and the shielded electrode are in the same potential focusing emission state. The negative terminal of the power supply is connected to the ground circuit return line, and the current returns through the ground circuit electrode, thereby collecting the second total output current, the second ground circuit current, the second main electrode current and the second shielded electrode current. The leakage current operator is calculated using the second ground circuit current, the second main electrode current and the second shielding electrode current. If the ratio of the leakage current operator to the second total output current is greater than the first target value, it is determined that the system has a dynamic leakage current. Check whether the drill rod insulation is scratched or the cable sheath is damaged by pressure. If the background resistivity obtained by scanning is lower than the pure slurry reference along the depth, the background data is determined to be distorted. It is necessary to confirm whether there are metal components in the formation, whether it has entered a high-mineralization brine layer, or whether the probe has been severely eccentrically attached to the wall. If the difference between the background resistance and the pure slurry reference is less than the second target value, the strong conductive stratum is determined, and the background curve is confirmed to be valid through system self-check. If the background resistance is within a reasonable formation resistance range set with the pure slurry reference, and satisfies the global current conservation being less than the dynamic leakage deviation threshold, then the background scan data is deemed valid, and the background resistance within the entire depth range of the pile location is locked as the background reference.

6. The method for identifying and self-diagnosing monitoring signals of the entire jet grouting pile process based on resistivity testing according to claim 5, characterized in that, The calculation of the leakage current operator includes: A= ( I 0+ I b)− I return; in, A For leakage current operator, I 0 represents the second main electrode current. I b is the second shielding electrode current. I return refers to the current in the second ground loop.

7. The method for identifying and self-diagnosing monitoring signals of the entire jet grouting pile process based on resistivity testing according to claim 1, characterized in that, The fourth stage of closed-loop identification of shallow in-pile detection mode includes: During the monitoring process, the relay group switches to shallow detection mode, that is, the positive terminal of the power supply is connected to the main electrode feeder, and the negative terminal of the power supply is switched to the shielded bus. At the same time, the ground circuit return line is disconnected by the controlled switch. The current is sent from the main electrode and flows back directly to the adjacent shielded electrode, forming a closed loop downhole, thereby collecting the main electrode branch current, the shielded branch return current and the shallow detection resistance. If the absolute deviation between the main electrode branch current and the shielded branch return current exceeds the third target value, it is determined that a conductive mud bridge has been formed between the electrodes and the anti-stick coating on the surface of the insulating short section has failed. If the shallow detection resistance is less than the pure slurry reference, it is determined that a water seepage short circuit has occurred inside the detection probe or that a structural electrical breakdown has occurred in the insulation short section. The probe sealing connection should be checked or the damaged insulation component should be replaced. If the shallow detection resistance is greater than the pure slurry reference or equal to the background reference, it is determined that the probe does not have enough slurry coating, the jet grouting at this depth section has failed or serious hole collapse has occurred, and the grouting pressure and slurry flow rate should be verified. If the shallow probe resistance is greater than the background reference, the electrode surface resistance is determined to be too high, and the probe is cleaned. If the shallow detection resistor is stably located in the lower range of the reference interval set by the background reference and the pure slurry reference, and satisfies the condition that the branch current is less than the dynamic leakage deviation threshold, then the measurement reference is determined to be valid.

8. The method for identifying and self-diagnosing monitoring signals of the entire jet grouting pile based on resistivity testing according to claim 7, characterized in that, The fifth stage of pile depth detection inversion logic and defect classification identification includes: During the monitoring process, a relay is used to switch the time-division multiplexing to return the circuit to the deep detection state, and the current flows to the ground loop electrode to obtain the deep detection resistance after being focused and squeezed. If the shallow detection resistance is greater than or equal to the deep detection resistance, it is determined that the shielding focusing function is lost, indicating that the probe may be in a severely tilted wall-attached state or that the shielding drive branch is faulty. If the shallow detection resistor and the deep detection resistor rise back to the background reference synchronously, the effective pile formation is determined to have failed, and the pressure parameters of the high-pressure jet pump are checked. If the shallow detection resistance maintains the low resistance characteristic of the grout while the deep detection resistance shows a step-like sudden increase, it is determined to be a local necking of the pile body; If the shallow detection resistor and the deep detection resistor exhibit a monotonically synchronous upward drift over time and are independent of spatial depth, it is determined that the detection electrode is continuously scaling, and the probe should be flushed. If the deep detection resistor is stably within the physical envelope range set by the shallow detection resistor and the background benchmark, and satisfies the closed-loop conservation of the total output current and the ground loop return current, then the deep detection resistor is determined to be effective. Combined with the true value of the feature locked at this depth and the background benchmark, the full pile length monitoring report and quality evaluation conclusion are obtained.

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