A bored pile hazard source identification and early warning system and monitoring method

Abstract

The application provides a bored pile danger source identification and early warning system and a monitoring method, relates to fault prediction and health management technology, and particularly relates to the technical field of bored pile danger source identification. A hoisting bar tension sensor is connected in series between the upper end of each hoisting bar and the hole support structure, and a pouring speed sensor is installed on the straight pipe section at the inlet of the concrete delivery pump pipe or the guide pipe, so that the comprehensive identification of the three major danger sources of the reinforcement cage floating, hole collapse and pouring interruption can be realized synchronously. Compared with the scheme in the prior art in which a plurality of sensors such as mud liquid level meters, ultrasonic hole wall detectors and guide pipe pressure sensors are arranged for each danger source, the number of sensors is reduced, and the system cost and installation complexity are reduced.

Description

Technical Field

[0001] This invention relates to fault prediction and health management technology; in particular, it relates to the field of hazard source identification technology for cast-in-place piles, specifically a hazard source identification and early warning system and monitoring method for cast-in-place piles. Background Technology

[0002] With the continuous advancement of infrastructure construction, bored piles have been widely used in bridges, high-rise buildings, and rail transit projects due to their advantages such as high bearing capacity and strong adaptability to geological formations. During the construction of bored piles, the three most common and serious quality accident hazards are: rebar cage floating, borehole wall collapse, and interruption of concrete pouring. Rebar cage floating can lead to insufficient rebar embedment depth and excessive protective layer thickness, severely affecting the bearing capacity of the pile foundation; borehole wall collapse can cause defects such as pile necking, mud inclusion, and pile breakage; and if the interruption of pouring is not handled promptly, it is highly likely to develop into pile breakage, causing significant economic losses and safety hazards. Therefore, real-time identification and early warning of these three hazards during the construction phase are crucial for ensuring the quality of bored pile construction.

[0003] Currently, the industry's monitoring of hazards in cast-in-place piles is mainly based on separate and independent monitoring, requiring the deployment of different types of sensors for each hazard. For example, utility model patent CN218148302U discloses a rebar cage floating observation device, which relates to the field of cast-in-place pile construction technology. It includes upper and lower support components and column components connected between the support components. The support components include three elastic telescopic rods located on the same horizontal plane, which are connected to form an equilateral triangle. The outer telescopic end of each elastic telescopic rod is connected to a connecting sleeve that can be sleeved with the end of the main reinforcement bar of the external rebar cage. The column components include three vertical support rods, the upper and lower ends of which are fixedly connected to the upper and lower support components respectively. By controlling the top elevation of the observation cage, it is possible to intuitively and quickly determine whether the rebar cage is floating, solving the problem that rebar cages are prone to floating in ultra-deep cast-in-place piles, and that such floating is difficult to observe.

[0004] For example, invention patent CN115830818A discloses a method, device, equipment, and system for early warning during bored pile construction, relating to the field of building construction technology. This system acquires key parameters of the reinforcing cage during the reinforcing cage fabrication stage and issues early warnings; it issues early warnings based on drilling parameters of individual boreholes during the drilling construction stage; and it acquires pouring parameters such as slump, specimen strength, filling coefficient, and pouring time during the concrete pouring stage and issues early warnings. Based on the parameters at each stage, it generates quality scores for the reinforcing cage, boreholes, and pouring construction, ultimately determining the overall quality score for the bored pile construction. This method transforms passive quality inspection into proactive early warning, improving the accuracy of quality control during the construction process.

[0005] For example, the invention patent with publication number CN118835981A discloses a sensor-based intelligent monitoring method for reinforced concrete cast-in-place pile grouting, relating to the field of concrete grouting construction technology. This method involves conducting geological surveys during drilling using multi-stage drilling equipment, and sensing risks to the surrounding borehole wall and drilling itself when switching drill bits based on the geological survey results. This allows for flexible adjustments to the drilling status. Simultaneously, after switching drill bits, drilling deviations are identified, and targeted corrective adjustments are made based on geological changes and the amount of deviation before and after the switch. This ensures, to a certain extent, the continuity of construction and better controls the stability of the borehole wall.

[0006] Currently, while the industry's technology for monitoring hazardous sources in cast-in-place piles has achieved segmented monitoring, it still suffers from the following shortcomings: Existing solutions typically require the deployment of multiple sensors, such as mud level gauges, ultrasonic borehole wall detectors, guide pipe pressure sensors, and displacement sensors, for each type of hazardous source. This results in a large number of sensors, high costs, complex installation, and significant interference at the construction site. Existing technologies often employ single thresholds or simple over-limit alarm methods, providing only a binary "present / absent" risk assessment, which fails to reflect the urgency of the hazard's development and is prone to missed and false alarms. Existing technologies fail to utilize the same sensor signal to comprehensively identify three hazardous sources: uplift, borehole collapse, and grouting interruption, leading to redundancy in the monitoring system and severe data silos. Regarding borehole collapse identification, existing technologies lack effective means to eliminate the interference of instantaneous fluctuations in top support force caused by rapid concrete pouring, resulting in a high false alarm rate for borehole collapse. In terms of grouting interruption identification, existing technologies rely heavily on guide pipe pressure or concrete interface monitoring, failing to fully utilize the trend reversal characteristics of the lifting bar tension signal before grouting interruption, making it difficult to gain sufficient time for intervention before pile breakage occurs.

[0007] Therefore, a system for identifying and warning of hazards in cast-in-place piles and a monitoring method are provided. Summary of the Invention

[0008] To address the problems mentioned in the background art, the present invention provides the following technical solution: a hazard source identification and early warning system for cast-in-place piles, comprising: The suspension rod tension detection component includes at least one suspension rod tension sensor connected in series between the suspension rod of the steel cage and the orifice support structure for real-time acquisition of suspension rod tension signals; The grouting speed sensor is installed in the concrete grouting pipeline to collect grouting speed signals; The data acquisition unit is connected to the suspension tension sensor and the injection speed sensor; The buoyancy risk analysis unit, connected to the data acquisition unit, is used to identify whether the tension of the suspension rod shows a continuous downward trend, and to determine the buoyancy risk level based on the rate of decrease in tension. The higher the rate of decrease, the higher the risk level. The hole collapse risk analysis unit, connected to the data acquisition unit, is used to identify whether the tension of the suspension rod shows a continuous abnormal increase trend, and to determine the hole collapse risk level based on the rate of increase of tension; the higher the rate of increase, the higher the risk level. The hole collapse risk analysis unit also receives the injection speed signal. When the tension increases abnormally and the injection speed does not exceed the preset injection speed threshold, the hole collapse risk signal is confirmed and output; when the tension increases abnormally but the injection speed exceeds the injection speed threshold, the output of the hole collapse risk signal is suppressed. The injection interruption risk analysis unit, connected to the data acquisition unit, is used to identify whether the downward trend of the suspension rod tension has turned into stagnation or rebound, provided that the buoyancy risk analysis unit has already output the buoyancy risk signal, and at the same time the injection speed is lower than the minimum injection speed threshold. If so, the injection interruption risk signal is output. A multi-level early warning output unit is connected to the aforementioned risk analysis units and is used to trigger corresponding early warning actions based on each risk signal.

[0009] A method for identifying, warning, and monitoring hazards in cast-in-place piles, employing a hazard identification and early warning system for cast-in-place piles, includes the following steps: S1. Connect a tension sensor for the lifting rod in series between the lifting rod and the orifice support structure, and install a grouting speed sensor in the grouting pipeline. S2. Real-time acquisition of suspension rod tension signal and grouting speed signal; S3. Perform multi-mode trend analysis on the tension signal of the suspension rod: When the tension continues to decrease, calculate the rate of decrease of the tension and determine the risk level of the upward movement based on the rate of decrease. The higher the rate of decrease, the higher the risk level. When the tension continues to increase abnormally, it is simultaneously determined whether the injection rate exceeds the injection rate threshold; if it does not exceed the threshold, the tension increase rate is calculated, and the collapse risk level is determined based on the increase rate. The higher the increase rate, the higher the risk level; if it exceeds the threshold, the output of the collapse risk signal is suppressed. When the upward risk signal has been triggered, but the downward trend of the pull force turns to stagnation or rebound, and the injection rate is lower than the minimum threshold, the injection interruption risk level is determined according to the pull force rebound rate. The higher the rebound rate, the higher the risk level. S4. Trigger corresponding multi-level early warnings based on each risk signal.

[0010] The present invention has the following beneficial effects: 1. This invention connects a tension sensor in series between the upper end of each lifting rod and the borehole support structure, and installs a grouting speed sensor on the straight pipe section at the inlet of the concrete delivery pump pipe or conduit. This allows for the simultaneous comprehensive identification of three major hazards: rebar cage floating, borehole collapse, and grouting interruption. Compared to existing technologies that require multiple sensors such as mud level gauges, ultrasonic borehole wall detectors, and conduit pressure sensors for each hazard, this invention reduces the number of sensors, lowers system costs, and reduces installation complexity.

[0011] 4. This invention uses an uplift risk analysis unit to perform trend analysis on the tension values ​​of the four lifting rod tension sensors, outputting low uplift risk, medium uplift risk, and high uplift risk signals respectively based on the descent rate; an inlet collapse risk analysis unit 5 analyzes the increasing trend of the tension values ​​of each lifting rod tension sensor, outputting low inlet collapse risk, medium inlet collapse risk, and high inlet collapse risk signals respectively based on the increasing rate; and an injection interruption risk analysis unit outputs medium or high inlet collapse interruption risk signals based on the recovery rate. This three-level progressive early warning system transforms the binary judgment of "presence / absence" risk into a refined classification, effectively reducing false alarms and missed alarms.

[0012] 3. The three hazard sources—floating, hole collapse, and interrupted pouring—correspond to three change modes in the tension signal of the lifting rod: a continuous decrease, an abnormal increase, and a trend reversal, respectively. In hole collapse detection, the hole collapse risk analysis unit simultaneously reads the pouring speed signal for verification: if the pouring speed continuously exceeds the pouring speed threshold, the output of the hole collapse risk signal is suppressed, and only the judgment result of the floating risk analysis unit is retained; if the pouring speed does not exceed the threshold, the hole collapse risk signal is confirmed and output. This verification mechanism effectively eliminates the interference of rapid concrete pouring on hole collapse detection and reduces the false alarm rate of hole collapse.

[0013] 4. This invention provides early warning by monitoring the changing trend of the lifting bar tension. When the concrete level rises to the bottom of the reinforcing cage and generates a supporting force, the lifting bar tension decreases by the same amount. The tension reduction signal appears before the actual displacement of the reinforcing cage. When the maximum vertical displacement exceeds the displacement warning threshold, the four laser rangefinders of the cage top displacement sensor group take over from the lifting bar tension sensor to provide final confirmation, thus compensating for the monitoring blind spot in the constraint failure stage when relying solely on the tension sensor.

[0014] 5. When four lifting rod tension sensors are installed, the floating risk analysis unit determines the tension balance: if the maximum difference in tension values ​​of the four lifting rod tension sensors exceeds the average value at the same time, it is marked as a tension imbalance state, indicating that the rebar cage may be tilted or locally floating. The hole collapse risk analysis unit determines the collapse range: if only one or two lifting rod tension sensors show an abnormal increase in tension, it is judged as a local collapse risk in the corresponding location; if all four lifting rod tension sensors show an abnormal increase at the same time, it is judged as an overall collapse risk. The output signal clearly indicates the collapse range, providing accurate directional information for taking targeted measures on site and avoiding blind actions.

[0015] Of course, any product implementing this invention does not necessarily need to achieve all of the above advantages at the same time. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall invention.

[0017] Figure 2 This is a flowchart of the method of the present invention.

[0018] In the diagram: 1. Stirring tension detection component; 2. Grouting speed sensor; 3. Data acquisition unit; 4. Floating risk analysis unit; 5. Hole collapse risk analysis unit; 6. Grouting interruption risk analysis unit; 7. Cage top displacement sensor group; 8. Multi-level early warning output unit; 81. On-site audible and visual alarm; 82. Cab display screen; 20. Reinforcing cage; 21. Stirring bar; 22. Hole opening support structure. Detailed Implementation

[0019] 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.

[0020] Please see Figures 1 to 2 The present invention provides a technical solution: Example 1: System Structure like Figure 1 As shown, this embodiment provides a hazard source identification and early warning system for cast-in-place piles, including a lifting rod tension detection component 1, a grouting speed sensor 2, a data acquisition unit 3, a floating risk analysis unit 4, a hole collapse risk analysis unit 5, a grouting interruption risk analysis unit 6, a cage top displacement sensor group 7, and a multi-level early warning output unit 8.

[0021] like Figure 1As shown, the suspension rod tension detection assembly 1 includes four suspension rod tension sensors 11. The reinforcing cage 20 is suspended from the borehole support structure 22 by four suspension rods 21, which are evenly distributed around the top circumference of the reinforcing cage 20. A suspension rod tension sensor 11 is connected in series between the upper end of each suspension rod 21 and the borehole support structure 22 to collect the tension signal borne by each suspension rod 21 in real time. This series connection method does not change the original force path of the suspension rod 21 connection, the force transmission path is clear, and the measurement results directly reflect the accumulation process of the top support force.

[0022] The tension sensor 11 for the lifting rod is an S-type tension / compression sensor with a range of 0-100kN (the appropriate range can be selected according to the self-weight of the reinforcing cage 20), an accuracy of 0.01kN, and an output signal of 4-20mA or RS-485 digital signal. Both ends of the tension sensor 11 are connected to the upper end of the lifting rod 21 and the orifice support structure 22 via shackles or threaded connections.

[0023] Before the pouring begins, the self-weight G of the reinforcing cage 20 is borne by the four lifting bars 21, and the initial reading of the tension sensor 11 for each lifting bar is approximately G / 4. When the concrete level rises to the bottom of the reinforcing cage 20 and generates a supporting force... At that time, the tension T of the suspension rod decreases by the same amount ( By continuously monitoring the changes and rate of change of the tension T in the lifting rods, precursory signals of upward movement can be detected before the actual displacement of the steel cage 20 occurs, thus gaining valuable time for emergency response.

[0024] The injection velocity sensor 2 uses an electromagnetic flow meter, which is installed on the straight pipe section at the inlet of the concrete delivery pump pipe or conduit to collect the volumetric flow rate signal of the concrete entering the conduit in real time. The electromagnetic flow meter is a non-contact measurement method, suitable for concrete media containing coarse aggregate, and can work stably for a long time in harsh construction environments.

[0025] Data acquisition unit 3 is deployed on an industrial-grade embedded controller and is connected to four lifting rod tension sensors 11 and grouting speed sensors 2 via an RS-485 bus, synchronously acquiring all signals at a sampling frequency of 5Hz. The RS-485 bus has strong anti-interference capabilities and long transmission distance, making it suitable for the electromagnetic environment of the construction site. The acquired signals are filtered by moving average and then sent to each risk analysis unit, effectively eliminating instantaneous interference such as construction machinery vibration and improving the accuracy of trend analysis.

[0026] The buoyancy risk analysis unit 4 is used to identify precursor signals of the rebar cage 20's buoyancy and output graded warnings based on the rate of tension descent, directly linking the warning level to the urgency of the danger. The buoyancy risk analysis unit 4 uses a 60-second sliding analysis window, sliding once every 12 seconds, to perform trend analysis on the tension values ​​of the four lifting rod tension sensors 11. Within each window, the rate of tension descent is calculated: the tension value at the beginning of the window minus the tension value at the end of the window, then divided by the window duration of 60 seconds, in kN / min.

[0027] In this embodiment, the first descent rate threshold is set to 0.05 kN / min, and the second descent rate threshold is set to 0.15 kN / min.

[0028] The risk level is determined based on the descent rate: a descent rate < 0.05 kN / min is considered low risk; 0.05-0.15 kN / min is considered medium risk, requiring continuous monitoring and preparation for rate reduction; and ≥ 0.15 kN / min is considered high risk, requiring immediate rate reduction or suspension of injection. This three-tiered progressive warning system transforms the binary judgment of "presence / absence" risk into a refined classification, effectively reducing missed and false alarms.

[0029] The uplift risk analysis unit 4 also incorporates injection rate signals for risk level correction. The adaptive threshold module has preset injection rate thresholds categorized by geological conditions: 0.8 m³ / min for sandy soil, 1.2 m³ / min for cohesive soil, and 1.5 m³ / min for gravelly soil. When the injection rate exceeds the corresponding threshold, the risk level is increased by one level (if already at the highest level, it remains at the highest level). Furthermore, the uplift risk analysis unit 4 also includes a tension balance judgment function: when the maximum difference in tension values ​​from the four suspension rod tension sensors 11 exceeds 20% of the average value at the same time, it is marked as a tension imbalance state, and the risk level is increased by one level.

[0030] The borehole collapse risk analysis unit 5 is used to identify precursor signals of borehole wall collapse and output graded early warnings based on the rate of increase in tension. Its mechanical principle is as follows: When the borehole wall collapses, the collapsed soil generates downward lateral friction and drag force on the reinforcing cage 20, resulting in an abnormal increase in the tension of the lifting bars. This increase is opposite to the direction of the decrease in tension caused by the increase in the jacking force, and can be distinguished by the increasing trend of the tension signal. Thus, the same sensor can be used to achieve simultaneous monitoring of two hazard sources: uplift and borehole collapse.

[0031] The borehole collapse risk analysis unit 5 uses a 30-second analysis window, sliding every 6 seconds, to analyze the increasing trend of the tension values ​​of each lifting rod tension sensor 11. The increase rate is calculated as follows: the tension value at the end of the window minus the tension value at the beginning of the window, then divided by the window duration of 30 seconds, converted to kN / min. In this embodiment, the first increase rate threshold is set to 0.20 kN / min, and the second increase rate threshold is set to 0.50 kN / min. The borehole collapse risk level is determined according to the increase rate: an increase rate < 0.20 kN / min is low risk; 0.20-0.50 kN / min is medium risk, requiring immediate inspection of mud circulation and stabilization of the borehole wall; ≥ 0.50 kN / min is high risk, requiring the initiation of an emergency response.

[0032] Before outputting the hole collapse risk signal, the hole collapse risk analysis unit 5 synchronously reads the injection speed signal for verification: if the injection speed continuously exceeds the injection speed threshold, the hole collapse risk signal output is suppressed, and only the judgment result of the floating risk analysis unit 4 is retained; if the injection speed does not exceed 70% of the threshold, the hole collapse risk signal is confirmed to be output. When four suspension rod tension sensors 11 are provided, the hole collapse risk analysis unit 5 also has a local hole collapse positioning function: if only one or two suspension rod tension sensors 11 show an abnormal increase in tension, it is judged as a local hole collapse risk in the corresponding direction; if all four suspension rod tension sensors 11 show an abnormal increase at the same time, it is judged as an overall hole collapse risk.

[0033] The grouting interruption risk analysis unit 6 is used to identify the risk of grouting interruption caused by conduit blockage, material supply interruption, or conduit pull-out from the concrete surface. Its judgment is based on the following premise: the upward floating risk analysis unit 4 has output a medium or high upward floating risk signal. When the premise is met, it first determines whether the grouting speed is lower than the minimum grouting speed threshold (set to 0.1 m³ / min in this embodiment); while the grouting speed is lower than the threshold, it further judges the tensile force trend change: if the sum of tensile force values ​​changes by less than ±2% within 120 seconds, a medium signal for grouting interruption risk due to conduit blockage is output; if the tensile force rebounds, the rebound rate is calculated (the sum of current tensile force values ​​minus the sum of tensile force values ​​120 seconds ago, divided by 120 seconds). When the rebound rate is <0.10 kN / min, a medium signal for interruption risk due to cavitation is output; when it is ≥0.10 kN / min, a high signal for interruption risk due to cavitation is output. By distinguishing between the two types of malfunctions, namely blockage and voiding, operators can quickly determine the cause of the malfunction: for blockage, the conduit should be cleared or lifted; for voiding, the conduit depth should be immediately reduced and re-buried below the concrete surface.

[0034] The cage top displacement sensor group 7 includes four laser rangefinders 71, which are evenly distributed along the top circumference of the reinforcing cage 20 and installed on the orifice casing or independent support, illuminating the top surface of the reinforcing cage 20 vertically downwards. When the maximum vertical displacement exceeds the displacement warning threshold of 20mm, the floating risk level is directly raised to the highest level, indicating that the floating of the reinforcing cage 20 has actually occurred.

[0035] The multi-level early warning output unit 8 includes a field audible and visual alarm 81 and a cab display screen 82. The correspondence between early warning levels and actions is as follows: When the risk of upward movement is low and there is no risk of hole collapse or interruption of grouting, the alarm is not triggered, and the display screen 82 displays real-time data with a green background; when the risk of upward movement is medium or the risk of hole collapse is low, the yellow warning light is constantly on, and the display screen 82 displays the risk type and rate of change with a yellow indicator; when the risk of upward movement is high, the risk of hole collapse is medium, or the risk of interruption of grouting is medium, the yellow warning light flashes at a frequency of 1Hz, and the display screen 82 displays abnormal parameters and suggested measures with an orange indicator; when the risk of upward movement is at its highest level, the risk of hole collapse is high, or the risk of interruption of grouting is high, the red warning light flashes at a frequency of 2Hz, the buzzer sounds continuously, the display screen 82 displays an emergency stop command with a red flashing indicator, and the linkage interface with the concrete pumping equipment is triggered to automatically stop pumping. The early warning priority from high to low is as follows: displacement exceeding limit > high grouting interruption / high hole collapse > medium grouting interruption / medium hole collapse / high upward movement > medium upward movement / low hole collapse > low upward movement.

[0036] Example 2: Monitoring Method like Figure 2 As shown, this embodiment provides a method for identifying, warning, and monitoring hazardous sources in cast-in-place piles using the system described in Embodiment 1, comprising the following steps: Step S1: Sensor Deployment. Before or after lowering the reinforcing cage 20, connect four tension sensors 11 in series between the upper ends of the four lifting rods 21 and the orifice support structure 22, ensuring that the force axis coincides with the lifting rod axis during installation. Install an electromagnetic flow meter as a grouting speed sensor 2 on a straight section of the concrete conveying pump pipe, leaving at least 5 times the pipe diameter of the straight pipe section before and after the installation position. Install four laser rangefinder sensors 71 on the orifice casing or independent support, adjusting the angle so that they perpendicularly illuminate the four measuring points on the top surface of the reinforcing cage 20.

[0037] Step S2: Initial Data Acquisition and Benchmark Setting. Before the grouting begins, the data acquisition unit 3 collects initial readings from each sensor for 60 seconds, and takes the average value as the initial tension value benchmark for each suspension rod tension sensor 11 and the initial displacement benchmark for each laser rangefinder sensor 71. Based on the construction geological survey report, the corresponding geological conditions are selected, and the corresponding grouting speed threshold is applied.

[0038] Step S3: Real-time data acquisition and multi-mode trend analysis. During the concrete pouring process, data acquisition unit 3 continuously acquires the tension of the lifting rod, the pouring speed, and the displacement signals at a sampling frequency of 5Hz. After being filtered by moving average, the data is sent to the floating risk analysis unit 4, the hole collapse risk analysis unit 5, and the pouring interruption risk analysis unit 6 for parallel analysis.

[0039] Upward buoyancy analysis: Using a 60s window and a 12s step size, determine whether the tension of each suspension rod tension sensor 11 is continuously decreasing; if it is decreasing, calculate the rate of decrease, and output a low upward buoyancy risk signal, a medium upward buoyancy risk signal, and a high upward buoyancy risk signal according to the rate of decrease: <0.05kN / min, 0.05-0.15kN / min, and ≥0.15kN / min, respectively. Level correction is performed based on the injection speed: when the injection speed exceeds the injection speed threshold, the level is increased by one level from the current level. Simultaneously, tension balance is assessed: when the maximum difference between the tension values ​​of the four suspension rod tension sensors 11 exceeds 20% of the average value, the risk level is increased by one level.

[0040] Borehole collapse analysis: Using a 30-second window and a 6-second step, determine whether the tension of each suspension rod tension sensor 11 is continuously and abnormally increasing; if it is increasing, calculate the increase rate and simultaneously verify the injection speed. If the injection speed does not exceed 70% of the threshold and the tension is abnormally increasing, output a low-risk, medium-risk, and high-risk collapse signal respectively based on the increase rate <0.20kN / min, 0.20-0.50kN / min, and ≥0.50kN / min, and determine whether it is a local or overall borehole collapse; if the injection speed continuously exceeds the injection speed threshold, suppress the output of the borehole collapse signal.

[0041] Perfusion interruption analysis: Under the premise that the upward risk medium signal or upward risk high signal has been triggered, monitor whether the perfusion rate is lower than 0.1 m³ / min; if it is lower, judge the change in tension trend: if the tension fluctuates less than ±2% within 120s, it is judged as a medium signal of catheter blockage-type perfusion interruption risk; if the tension rises, calculate the rise rate, and output a medium signal of cavitation interruption risk or a high signal of cavitation interruption risk according to the rise rate <0.10 kN / min or ≥0.10 kN / min respectively.

[0042] Step S4: Comprehensive Early Warning Output. The multi-level early warning output unit 8 summarizes the judgment results of each analysis unit and the cage top displacement sensor group 7, and drives the on-site audible and visual alarm 81 and the cab display screen 82 according to the priority of displacement exceeding the limit > high grouting interruption / high collapse > medium grouting interruption / medium collapse / high buoyancy > medium buoyancy / low collapse > low buoyancy. Different colors, flashing modes and text labels are used to distinguish the type of hazard and risk level, and trigger the corresponding linkage control actions.

[0043] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, adaptive adjustments can be made to the sensor type, range parameters, rate threshold values, analysis window duration, and combination rules of judgment channels in the above embodiments without departing from the concept of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0044] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0045] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A hazard identification and early warning system for cast-in-place piles, characterized in that, include: The lifting rod tension detection component (1) includes at least one lifting rod tension sensor connected in series between the lifting rod (21) of the steel cage (20) and the orifice support structure (22) for real-time acquisition of the lifting rod tension signal; The grouting speed sensor (2) is installed in the concrete grouting pipeline to collect grouting speed signals; The data acquisition unit (3) is connected to the suspension rod tension sensor and the injection speed sensor (2); The buoyancy risk analysis unit (4) is connected to the data acquisition unit (3) and is used to identify whether the tension of the suspension rod shows a continuous downward trend, and to determine the buoyancy risk level according to the rate of decrease of the tension. The higher the rate of decrease, the higher the risk level. The hole collapse risk analysis unit (5) is connected to the data acquisition unit (3) and is used to identify whether the tension of the suspension rod shows a continuous abnormal increase trend, and to determine the hole collapse risk level according to the increase rate of tension. The higher the increase rate, the higher the risk level. The hole collapse risk analysis unit (5) also receives the injection speed signal. When the tension increases abnormally and the injection speed does not exceed the preset injection speed threshold, the hole collapse risk signal is confirmed and output. When the tension increases abnormally but the injection speed exceeds the injection speed threshold, the output of the hole collapse risk signal is suppressed. The infusion interruption risk analysis unit (6) is connected to the data acquisition unit (3) and is used to identify whether the downward trend of the suspension rod tension has turned into stagnation or rebound, and at the same time the infusion speed is lower than the minimum infusion speed threshold, provided that the floating risk analysis unit (4) has output the floating risk signal. If so, the infusion interruption risk signal is output. The multi-level early warning output unit (8) is connected to the above-mentioned risk analysis units and is used to trigger corresponding early warning actions based on each risk signal.

2. The hazard source identification and early warning system for cast-in-place piles according to claim 1, characterized in that, The upward risk analysis unit (4) classifies the risks based on the rate of pull descent: When the rate of decrease of the pulling force is less than the first rate of decrease threshold, a low risk of upward movement signal is output. When the rate of descent of the tension is greater than or equal to the first descent rate threshold and less than the second descent rate threshold, an upward risk signal is output. When the rate of pull descent is greater than or equal to the second descent rate threshold, a high risk of upward movement is output. The second descent rate threshold is greater than the first descent rate threshold.

3. The hazard source identification and early warning system for cast-in-place piles according to claim 1, characterized in that, The hole collapse risk analysis unit (5) classifies the risks according to the rate of increase in tensile force: When the rate of increase of tension is less than the first rate of increase threshold, a low risk signal for hole collapse is output. When the rate of increase of tension is greater than or equal to the first rate of increase threshold and less than the second rate of increase threshold, a signal indicating the risk of hole collapse is output. When the rate of increase of tensile force is greater than or equal to the second rate of increase threshold, a high risk signal for hole collapse is output. The second increase rate threshold is greater than the first increase rate threshold.

4. The hazard source identification and early warning system for cast-in-place piles according to claim 1, characterized in that, The injection interruption risk analysis unit (6) determines the injection interruption risk level based on the rate at which the downward trend of tensile force turns into stagnation or recovery: When the rate of force recovery is less than the first recovery rate threshold, a signal indicating a risk of injection interruption is output. When the rate of force recovery is greater than or equal to the first recovery rate threshold, a high risk signal for injection interruption is output.

5. The hazard identification and early warning system for cast-in-place piles according to claim 1, characterized in that, The upward risk analysis unit (4) also makes a comprehensive judgment based on the injection speed signal. When the tension of the lifting rod continues to decrease and the injection speed exceeds the injection speed threshold, the risk level is increased by one level based on the current tension decrease rate. If the current level is already the highest level, it remains the highest level.

6. The hazard source identification and early warning system for cast-in-place piles according to claim 1, characterized in that, The suspension rod tension detection component (1) includes multiple suspension rod tension sensors corresponding to multiple suspension rods (21); the buoyancy risk analysis unit (4) is also used to determine whether the difference in tension value of each sensor exceeds the balance threshold. If so, the buoyancy risk level is raised by one level. If it is already at the highest level, it remains at the highest level; the hole collapse risk analysis unit (5) is also used to identify whether only some sensors have abnormally increased tension. If so, it is located as a local hole collapse risk.

7. The hazard source identification and early warning system for cast-in-place piles according to claim 1, characterized in that, It also includes a cage top displacement sensor group (7) for collecting vertical displacement signals on the top surface of the steel cage (20); when the vertical displacement value exceeds the displacement warning threshold, the risk level output by the floating risk analysis unit (4) is the highest level.

8. A method for identifying, warning, and monitoring hazardous sources in cast-in-place piles, characterized in that, The hazard identification and early warning system for cast-in-place piles according to any one of claims 1 to 7 includes the following steps: S1. Connect a tension sensor for the lifting rod (21) in series between the lifting rod (21) and the orifice support structure (22), and install a grouting speed sensor (2) in the grouting pipeline. S2. Real-time acquisition of suspension rod tension signal and grouting speed signal; S3. Perform multi-mode trend analysis on the tension signal of the suspension rod: When the tension continues to decrease, calculate the rate of decrease of the tension and determine the risk level of the upward movement based on the rate of decrease. The higher the rate of decrease, the higher the risk level. When the tension continues to increase abnormally, it is simultaneously determined whether the injection rate exceeds the injection rate threshold; if it does not exceed the threshold, the tension increase rate is calculated, and the collapse risk level is determined based on the increase rate. The higher the increase rate, the higher the risk level; if it exceeds the threshold, the output of the collapse risk signal is suppressed. When the upward risk signal has been triggered, but the downward trend of the pull force turns to stagnation or rebound, and the injection rate is lower than the minimum threshold, the injection interruption risk level is determined according to the pull force rebound rate. The higher the rebound rate, the higher the risk level. S4. Trigger corresponding multi-level early warnings based on each risk signal.

9. The method for identifying, warning, and monitoring hazardous sources in cast-in-place piles according to claim 8, characterized in that, The method for determining the buoyancy risk level in step S3 is as follows: when the pulling force descent rate is less than the first descent rate threshold, a low buoyancy risk signal is output; when the pulling force descent rate is greater than or equal to the first descent rate threshold and less than the second descent rate threshold, a medium buoyancy risk signal is output. When the rate of pull descent is greater than or equal to the second descent rate threshold, a high risk of upward movement is output.

10. The method for identifying, warning, and monitoring hazardous sources in cast-in-place piles according to claim 8, characterized in that, Step S3 also includes: adjusting the buoyancy risk level based on the injection speed signal. When the injection speed exceeds the injection speed threshold, the risk level is increased by one level based on the current pull descent rate. If the current level is already the highest level, it remains the highest level.

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