Cast-in-place pile concrete pouring elevation laser measurement and control method and system

Abstract

The invention discloses a cast-in-place pile concrete pouring elevation laser measurement and control method and a cast-in-place pile concrete pouring elevation laser measurement and control system, and relates to the technical field of cast-in-place pile construction quality control, and the cast-in-place pile concrete pouring elevation laser measurement and control method comprises the following steps: system initialization and triple characteristic calibration, triple signal cooperative detection in a pouring process, and real elevation calculation and linkage control. According to the invention, a gradient pulse cluster laser modulation technology, a triple signal collaborative recognition mechanism of frequency multiplication signal intensity-polarization rotation angle-dielectric relaxation time constant, a three-dimensional threshold recognition coordinate system and a dynamic correction algorithm are utilized; the problem of false elevation caused by the fact that a mud cake-laitance-concrete condensation layer three-phase interface cannot be distinguished in an existing laser measurement and control technology is solved, the defects that the manual rechecking efficiency is low, and ultrasonic detection is affected by mud concentration are overcome, accurate measurement and control of the real elevation of the concrete condensation layer of the cast-in-place pile is achieved, and the measurement and control accuracy is improved. And meanwhile, multi-dimensional quality early warning of concrete moisture content, mix proportion and the like is integrated, the construction efficiency and safety are improved, and various geological conditions are adapted.

Description

Technical Field

[0001] This invention relates to the field of quality control technology for cast-in-place pile construction, specifically to a laser measurement and control method and system for the elevation of cast-in-place pile concrete pouring. Background Technology

[0002] As the core foundation structure of bridges, high-rise buildings, and other engineering projects, the precise control of the concrete pouring elevation of cast-in-place piles directly determines the structural bearing capacity, durability, and overall safety and stability, making it a crucial aspect of engineering quality control. Currently, the mainstream technology for measuring and controlling concrete pouring elevation is laser measurement and control, supplemented by manual measuring ropes, ultrasonic testing, and other methods. Among these, laser measurement and control has become the preferred solution on-site due to its fast response speed and high ranging accuracy.

[0003] The core logic of existing laser measurement and control technologies revolves around the vertical height of the concrete liquid surface. A laser beam is emitted from the transmitter, and the receiver captures the reflected signal from the liquid surface. The liquid level height is calculated based on the light propagation time or phase difference to determine whether the design elevation has been reached. However, problems exist in cast-in-place pile construction: during drilling, a 2-5cm thick layer of mud cake easily adheres to the borehole wall. When concrete is poured, the mud cake is disturbed and falls off, mixing with the laitance produced during pouring to form a mud cake-laitance composite layer covering the actual concrete settling layer. Because existing laser measurement and control technologies cannot distinguish the three-phase interface of mud slurry-mud cake-concrete settling layer, they can only capture the reflected signal from the surface of the composite layer. This results in the measurement result being the height of the composite layer surface, rather than the actual elevation of the concrete settling layer required by the project, leading to a false elevation phenomenon. Furthermore, while manual rope verification can partially correct deviations, it is cumbersome, inefficient, and the confined space and harsh environment inside the borehole can easily affect the continuity of pouring and pose safety risks. Ultrasonic detection is greatly affected by mud concentration, resulting in insufficient accuracy and stability.

[0004] In view of this, a laser measurement and control method and system for concrete pouring elevation of cast-in-place piles is provided to overcome the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a laser measurement and control method and system for the concrete pouring elevation of cast-in-place piles, so as to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention provides a laser measurement and control method for the concrete pouring elevation of cast-in-place piles, comprising the following steps:

[0007] Step 1, System Initialization and Triple Feature Calibration: Fix the measurement and control probe at the center of the bored pile hole and record the vertical distance Hbase from the probe to the designed elevation of the bottom of the hole; perform laser irradiation on the mud skin and slurry composite layer and the initial set concrete for construction respectively, calibrate the reference parameters of the mud skin and slurry composite layer and the frequency harmonic signal intensity threshold Sth, polarization rotation angle threshold θth, and dielectric relaxation time constant threshold τth of the concrete, establish a three-dimensional recognition coordinate system, and establish a correction coefficient matrix through pre-experimentation;

[0008] Step 2, Triple signal coordinated detection during the pouring process: During concrete pouring, gradient pulse cluster laser is continuously emitted and coaxial positioning light source is activated simultaneously to collect the frequency doubling signal intensity Sreal, polarization rotation angle θreal, and dielectric relaxation time constant τreal in real time. The geometric height Hgeo of the liquid surface is calculated based on the phase difference of the fundamental frequency light reflection.

[0009] Step 3, Calculation of True Elevation and Linkage Control: Determine the current interface type based on the three-dimensional recognition coordinate system. If it is a concrete setting layer, obtain the correction coefficient kτ based on the correction coefficient matrix τreal, calculate the mud skin and slurry composite layer thickness correction term Δh, and obtain the true elevation Htrue of the concrete setting layer. Output the pouring control signal based on the relationship between Htrue and the design elevation Hdes. After the machine stops, it will continue to monitor and generate a quality report, and trigger corresponding early warnings for abnormal signals.

[0010] Furthermore, in step 1, the gradient pulse cluster laser is formed by modulating the fundamental frequency laser. Each gradient pulse cluster contains 3 pulses, with the pulse amplitude increasing in a gradient ratio of 1:1.5:2 and the pulse interval increasing in a gradient ratio of 0.5μs:1μs:1.5μs.

[0011] Furthermore, the criteria for determining the three-dimensional recognition coordinate system in step 1 are: the intensity of the harmonic signal ≥ Sth, the polarization rotation angle ≥ θth, and the dielectric relaxation time constant ≥ τth; where Sth ≥ 10 -10 W, θth≥15°, τth≥30μs; the correction factor kτ ranges from 0.98 to 1.02, and the larger the dielectric relaxation time constant, the closer kτ is to 1.02.

[0012] Furthermore, in step 3, Δh is calculated as 0.01×(τreal-τth); the true elevation Htrue is calculated as Htrue=kτ×Hgeo-Δh; when Htrue=Hdes-8cm, the system issues a pre-alarm and outputs a deceleration pouring signal; when Htrue=Hdes, the system issues a stop alarm and outputs a shutdown signal, and continues monitoring for 3 minutes after shutdown.

[0013] A laser measurement and control system for the concrete pouring elevation of cast-in-place piles includes:

[0014] Calcium ion temporal coordinated laser emission module: used to emit gradient pulse cluster laser and position the laser spot, including a pulse laser emitter, a calcium ion response enhancement unit and a coaxial positioning light source. The calcium ion response enhancement unit has a built-in lithium borate crystal filter and a concave focusing mirror to modulate the fundamental frequency laser into gradient pulse clusters;

[0015] Triple signal receiving and analysis module: used to acquire and analyze laser reflection signals, including a frequency doubling signal detection unit, a polarization relaxation co-detection unit and a signal isolation unit. The frequency doubling signal detection unit has a built-in photomultiplier tube and a 266nm narrowband filter. The polarization relaxation co-detection unit includes a Sanjac interferometer and a time-domain response analysis subunit.

[0016] Triple Coupling Identification and Control Module: Used for interface judgment, elevation correction and early warning, including triple signal coupling processor, elevation correction unit and multi-state early warning unit. The triple signal coupling processor has a built-in three-dimensional threshold model of frequency doubling intensity, polarization angle and dielectric relaxation time.

[0017] Furthermore, the pulsed laser emitter is a semiconductor-pumped laser; the coaxial positioning light source uses a visible light LED with a wavelength of 650nm; and the time-domain response analytical subunit has a built-in high-speed sampler.

[0018] Furthermore, the signal isolation unit incorporates a dichroic filter and a metal shield to separate ambient stray light from electromagnetic interference signals; the elevation correction unit dynamically calibrates the height value based on the matching degree of the three-dimensional signal; and the multi-state early warning unit includes elevation accuracy warning, concrete mix proportion deviation warning, abnormal concrete moisture content warning, insufficient cement dosage warning, and excessive aggregate impurities warning.

[0019] Furthermore, the calcium ion time-domain coordinated laser emission module, the triple signal receiving and analysis module, and the triple coupling identification and control module are connected by signals. The triple coupling identification and control module is linked with the pouring equipment to output deceleration and shutdown control signals to the pouring equipment.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. By using the triple signal recognition of frequency doubling signal intensity, polarization rotation angle, and dielectric relaxation time constant, only the concrete setting layer can simultaneously meet the three-dimensional threshold requirements, completely eliminating the interference of mud skin and slurry composite layer, and accurately obtaining the true elevation of the concrete setting layer.

[0022] 2. The dielectric relaxation time constant can simultaneously monitor the concrete moisture content. Combined with the triple signal anomaly combination, it can trigger multiple warnings such as concrete mix ratio deviation, abnormal moisture content, insufficient cement content, and excessive aggregate impurities, thus avoiding potential construction quality problems in advance.

[0023] 3. Unaffected by mud concentration, it can be adapted to all geological conditions; no manual in-hole verification is required, avoiding operational safety risks in harsh environments, while ensuring the continuity of pouring and improving measurement and control efficiency.

[0024] 4. The core components of the system are all conventional optical and electronic components that can be produced in ordinary factories. No special high-end manufacturing technology is required, which reduces production and application costs and facilitates widespread adoption in engineering sites. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a laser measurement and control method and system for concrete pouring elevation of cast-in-place piles according to the present invention. Detailed Implementation

[0026] 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.

[0027] Please see Figure 1 The present invention provides a technical solution:

[0028] See Figure 1 As shown, an embodiment of a laser measurement and control method and system for concrete pouring elevation of cast-in-place piles is presented:

[0029] I. System:

[0030] 1. Calcium ion temporal coordinated laser emission module:

[0031] This module is used to emit specific lasers and achieve gradient pulse cluster modulation, and includes three sub-components:

[0032] Pulsed laser emitter: Outputs a fundamental frequency laser with a wavelength of 532 nanometers, using a common semiconductor pump laser that can be mass-produced; the pulse width is 1 nanosecond, the repetition frequency is 20 kHz, and the peak power is 8 kilowatts; this power design does not require femtosecond technology, which can reduce production difficulty;

[0033] Calcium ion response enhancement unit: It incorporates a lithium borate crystal filter and a concave focusing mirror. These two components work together to modulate the fundamental frequency laser into gradient pulse clusters. Each gradient pulse cluster consists of 3 pulses, with the pulse amplitude increasing in a gradient ratio of 1:1.5:2 and the pulse interval increasing in a gradient ratio of 0.5 microseconds:1 microseconds:1.5 microseconds. This time-domain gradient modulation design can actively excite the interface dielectric relaxation difference.

[0034] Coaxial positioning light source: A visible light LED with a wavelength of 650 nanometers is used to locate the landing point of the laser spot.

[0035] 2. Triple signal receiving and parsing module:

[0036] This module is used to acquire and analyze frequency harmonic signals, polarization rotation signals, and dielectric relaxation signals, and includes three sub-components:

[0037] Frequency doubling signal detection unit: It has a built-in ordinary photomultiplier tube and a 266-nanometer narrowband filter; the photomultiplier tube has a detection accuracy of 10 to the power of -12 watts, which can accurately capture the frequency doubling signal generated by calcium ion excitation; the 266-nanometer narrowband filter is used to filter stray light to ensure the purity of the frequency doubling signal.

[0038] The polarization relaxation co-detection unit includes a Saignac interferometer and a time-domain response analysis subunit. The Saignac interferometer is a conventional optical instrument that can be mass-produced, and its accuracy in measuring the polarization rotation angle reaches 0.01 degrees. The time-domain response analysis subunit has a built-in high-speed sampler with a sampling rate of 100 MHz, which can be produced in ordinary factories. This subunit extracts the dielectric relaxation time constant by acquiring the amplitude-time response curve of the reflected laser.

[0039] Signal isolation unit: Built-in dichroic filter and metal shield; the two structures work together to separate ambient stray light and electromagnetic interference signals, ensuring the stability of the received signal.

[0040] 3. Triple-coupling identification and control module:

[0041] This module is used to implement signal coupling judgment, elevation correction, and early warning, and includes three sub-components:

[0042] Triple signal coupling processor: Built-in three-dimensional threshold model of frequency doubling intensity, polarization angle and dielectric relaxation time; This model determines the interface type through the collaborative analysis of three types of signals;

[0043] Elevation correction unit: Based on the matching degree of three-dimensional signals, the height value obtained by the measurement is dynamically calibrated to ensure that the output height value is the true elevation of the upper surface of the concrete curing layer;

[0044] Multi-state early warning unit: It has three types of early warning functions, namely, standard elevation early warning, concrete mix ratio deviation early warning and concrete moisture content abnormality early warning; among them, the concrete moisture content abnormality early warning is a new function.

[0045] II. Measurement and Control Methods and Steps:

[0046] 1. System initialization and triple feature calibration:

[0047] This step includes the newly added dielectric relaxation time calibration, and the specific operation is as follows:

[0048] S1.1 Probe Installation: Fix the measurement and control probe at the center of the bored pile hole, ensuring that the probe axis is completely aligned with the bored pile axis; record the vertical distance from the probe to the design elevation of the bottom of the bored pile hole, and record this distance as Hbase;

[0049] S1.2, Benchmark calibration of mud skin and laitance composite layer:

[0050] S1.2.1. Inject construction mud into the bored pile hole, and the mud shall not contain free calcium ions; activate the calcium ion time-domain coordinated laser emission module to emit gradient pulse cluster laser into the mud;

[0051] S1.2.2 Record four types of parameters: The first type is the fundamental frequency light reflection phase difference, denoted as Φm and its value does not exceed 5 degrees; the second type is the polarization rotation angle, denoted as θm and its value does not exceed 5 degrees; the third type is the harmonic signal intensity, denoted as Sm and its value does not exceed 10 to the power of -13 watts; the fourth type is the dielectric relaxation time constant, denoted as τm and its value does not exceed 10 microseconds. This value reflects the fast dielectric relaxation speed of the mud skin slurry composite layer.

[0052] S1.3, Triple Characteristic Calibration of Concrete:

[0053] S1.3.1 Take the concrete mixture for construction and place it in a container simulating the grouting pile hole, and cure it until it reaches the initial setting state; start the calcium ion time-domain coordinated laser emission module to emit gradient pulse cluster lasers into the concrete in the initial setting state;

[0054] S1.3.2 Record three types of threshold parameters: The first type is the frequency harmonic signal intensity threshold, denoted as Sth and its value is not less than 10 to the power of -10 watts. This threshold is generated by calcium ion excitation. The second type is the polarization rotation angle threshold, denoted as θth and its value is not less than 15 degrees. This threshold is generated by the difference in dielectric constant. The third type is the dielectric relaxation time constant threshold, denoted as τth and its value is not less than 30 microseconds. This threshold reflects the slow dielectric relaxation speed of concrete.

[0055] S1.3.3 Establish a three-dimensional identification coordinate system: When the intensity of the frequency harmonic signal is greater than or equal to Sth, the polarization rotation angle is greater than or equal to θth, and the dielectric relaxation time constant is greater than or equal to τth, this region is the only identification area of ​​the concrete curing layer.

[0056] S1.4 Correction parameter calibration: Through three sets of pre-experiments of concrete with different mix proportions, a correction coefficient matrix was established. The correction coefficient in this matrix is ​​denoted as kτ. The value of kτ ranges from 0.98 to 1.02. The larger the dielectric relaxation time constant, the closer the value of kτ is to 1.02. This relationship shows that kτ is positively correlated with the density of concrete.

[0057] 2. Triple signal coordinated detection during the pouring process:

[0058] This step includes the newly added dielectric relaxation signal analysis, and the specific operation is as follows:

[0059] S2.1, Pouring Start: When concrete begins to be poured, the calcium ion time-domain co-emission laser module continuously emits gradient pulse cluster laser, and the coaxial positioning light source is started synchronously to locate the laser spot landing point.

[0060] S2.2, Triple signal acquisition:

[0061] S2.2.1 The frequency doubling signal detection unit collects the intensity of 266 nm frequency doubling light in real time, and this intensity is denoted as Sreal;

[0062] S2.2.2 The polarization relaxation co-detection unit simultaneously performs two operations: the first is to measure the polarization rotation angle, which is denoted as θreal; the second is to acquire the amplitude-time response curve of the reflected laser through a high-speed sampler, and calculate the real-time dielectric relaxation time constant based on the curve attenuation slope, which is denoted as τreal.

[0063] S2.2.3. The geometric height of the current liquid surface is calculated based on the phase difference of the fundamental frequency light reflection, and this height is denoted as Hgeo;

[0064] S2.3, Three-dimensional threshold coupling judgment:

[0065] If Sreal is less than Sth, or θreal is less than θth, or τreal is less than τth, then the current interface is determined to be a mud skin and slurry composite layer, the currently calculated Hgeo is discarded and monitoring continues;

[0066] If Sreal is greater than or equal to Sth, θreal is greater than or equal to θth, and τreal is greater than or equal to τth, then the current interface is determined to be a concrete settling layer, triggering an elevation correction operation.

[0067] If Sreal is greater than or equal to Sth, θreal is greater than or equal to θth, and τreal is less than τth, then a warning for excessive concrete moisture content is triggered.

[0068] 3. Actual elevation calculation and linkage control:

[0069] This step refines the correction logic, and the specific operations are as follows:

[0070] S3.1 Dynamic correction calculation:

[0071] Based on the real-time dielectric relaxation time constant τreal, query the correction coefficient matrix to obtain the correction coefficient kτ corresponding to the current concrete mix proportion;

[0072] Calculate the thickness correction term for the mud skin and slurry composite layer, denoted as Δh. Δh is calculated by multiplying 0.01 by the difference between τreal and τth. This calculation method reflects that the larger τreal is, the thinner the mud skin and slurry composite layer is, and the smaller the value of Δh is.

[0073] Calculate the true elevation of the concrete set layer, denoted as Htrue; Htrue is calculated by multiplying kτ by Hgeo and then subtracting Δh.

[0074] S3.2, Hierarchical linkage control:

[0075] When Htrue equals the design elevation Hdes minus 8 cm, the system issues a pre-alarm and outputs a deceleration pouring signal to the pouring equipment to avoid over-pouring or under-pouring.

[0076] When Htrue equals Hdes, the system issues a stop alarm and outputs a stop signal to the pouring equipment. The pouring equipment automatically stops after receiving the signal.

[0077] After shutdown, the system continuously monitors for 3 minutes. If the fluctuation range of the frequency harmonic signal strength Sreal, polarization rotation angle θreal, and dielectric relaxation time constant τreal does not exceed 5%, a report is generated. The report includes the standard elevation and the concrete quality being qualified. The qualified concrete quality is reflected in the normal moisture content and mix proportion.

[0078] S3.3, Abnormal Handling: If Sreal drops sharply during the monitoring process, an insufficient cement dosage warning will be triggered; if θreal drops sharply during the monitoring process, an excessive aggregate impurity warning will be triggered.

[0079] It should be noted that:

[0080] It employs a dual gradient design of amplitude and interval; this design can actively excite the dielectric relaxation difference at the interface, enabling the precise capture of dynamic physical characteristics; and it can be achieved using only a common signal generator.

[0081] The calcium ion frequency doubling chemical signal, the polarization rotation static physical signal, and the dielectric relaxation dynamic physical signal are combined to form an indispensable interface locking logic; this logic can completely eliminate misjudgment caused by a single signal.

[0082] By utilizing the dielectric relaxation time constant to simultaneously reflect the concrete moisture content and the thickness of the mud crust laitance composite layer, the function of analyzing multiple parameters in a single detection is achieved; no additional sensors are required.

[0083] For example:

[0084] Taking a cast-in-place pile with a diameter of 1.8 meters and a design elevation of -25 meters in a bridge project as an example, the details are as follows:

[0085] System initialization:

[0086] The vertical distance from the probe to the designed elevation at the bottom of the borehole, according to HBase, is 25 meters.

[0087] The benchmark calibration of the mud-slurry composite layer yielded the following results: the fundamental frequency light reflection phase difference Φm is 150 degrees, the polarization rotation angle θm is 4 degrees, the overtone signal intensity Sm is 8 x 10^-14 watts, and the dielectric relaxation time constant τm is 8 microseconds.

[0088] The triple characteristic calibration of concrete yielded the following results: the overtone signal strength threshold Sth is 6 x 10^-10 watts, the polarization rotation angle threshold θth is 20 degrees, and the dielectric relaxation time constant threshold τth is 35 microseconds.

[0089] The correction coefficient matrix is ​​set as follows: when the dielectric relaxation time constant is 35 microseconds, the correction coefficient kτ is 1.00; when the dielectric relaxation time constant is 45 microseconds, the correction coefficient kτ is 1.01; when the dielectric relaxation time constant is 55 microseconds, the correction coefficient kτ is 1.02.

[0090] Pouring process:

[0091] When the calculated geometric height of the liquid surface Hgeo is -24.9 meters, the intensity of the overtone signal Sreal is 4 x 10 to the power of -10 watts (less than Sth), the polarization rotation angle θreal is 12 degrees (less than θth), and the dielectric relaxation time constant τreal is 12 microseconds (less than τth), it is determined to be a mud skin and slurry composite layer.

[0092] When the calculated geometric height of the liquid surface Hgeo is -25.08 meters, the overtone signal strength Sreal is 7.2 x 10 to the power of -10 watts (greater than or equal to Sth), the polarization rotation angle θreal is 23 degrees (greater than or equal to θth), and the dielectric relaxation time constant τreal is 42 microseconds (greater than or equal to τth), it is determined to be a concrete curing layer.

[0093] Elevation correction:

[0094] When the dielectric relaxation time constant τreal is 42 microseconds, the corresponding correction factor kτ is 1.005;

[0095] The thickness correction term Δh for the mud skin and slurry composite layer is 0.01 multiplied by the difference between 42 microseconds and 35 microseconds, and the calculated Δh is 0.07 meters.

[0096] The actual elevation Htrue is calculated as 1.005 multiplied by -25.08 meters and then subtracted by 0.07 meters, resulting in Htrue being -25.0 meters (consistent with the design elevation). The system then issues a stop alarm.

[0097] Continuous monitoring:

[0098] After shutdown, continuous monitoring for 3 minutes showed that the frequency doubling signal strength Sreal stabilized between 7.0 x 10^-10 watts and 7.3 x 10^-10 watts, the polarization rotation angle θreal stabilized between 22 degrees and 24 degrees, and the dielectric relaxation time constant τreal stabilized between 40 microseconds and 43 microseconds.

[0099] A report was generated, which stated that the concrete level met the standard and that the concrete moisture content and mix proportions were normal, with no abnormal warnings.

[0100] Summarize:

[0101] Completely solves the false elevation problem: Only the concrete setting layer can simultaneously meet the threshold requirements of the triple signal, completely eliminating the interference of the mud skin and laitance composite layer;

[0102] The dielectric relaxation time constant τreal can simultaneously monitor the moisture content of concrete: when τreal is less than τth, it indicates that the concrete moisture content is too high and cracks are likely to occur; when τreal is greater than τth, it indicates that the concrete moisture content is too low and the density is insufficient.

[0103] By using abnormal combinations of three signals to correspond to different quality warnings, specifically, mix proportion deviation warning, aggregate impurity warning, and insufficient cement dosage warning, the integrated function of elevation measurement and control and concrete quality prediction is realized.

[0104] No manual verification is required, avoiding safety risks during borehole operations and improving measurement and control efficiency;

[0105] Unaffected by mud concentration, and because none of the three signals respond to the mud, it can adapt to all geological conditions.

[0106] The system components are all conventional optical and electronic components that can be produced in ordinary factories, making it easy to scale up and promote.

Claims

1. A method for laser measurement and control of the pouring elevation of a bored pile concrete, characterized in that, Includes the following steps: Step 1, System Initialization and Triple Feature Calibration: Fix the measurement and control probe at the center of the bored pile hole and record the vertical distance Hbase from the probe to the designed elevation of the bottom of the hole; perform laser irradiation on the mud skin and slurry composite layer and the initial set concrete for construction respectively, calibrate the reference parameters of the mud skin and slurry composite layer and the frequency harmonic signal intensity threshold Sth, polarization rotation angle threshold θth, and dielectric relaxation time constant threshold τth of the concrete, establish a three-dimensional recognition coordinate system, and establish a correction coefficient matrix through pre-experimentation; Step 2, Triple signal coordinated detection during the pouring process: During concrete pouring, gradient pulse cluster laser is continuously emitted and coaxial positioning light source is activated simultaneously to collect the frequency doubling signal intensity Sreal, polarization rotation angle θreal, and dielectric relaxation time constant τreal in real time. The geometric height Hgeo of the liquid surface is calculated based on the phase difference of the fundamental frequency light reflection. Step 3, Calculation of True Elevation and Linkage Control: Determine the current interface type based on the three-dimensional recognition coordinate system. If it is a concrete setting layer, obtain the correction coefficient kτ based on the correction coefficient matrix τreal, calculate the mud skin and slurry composite layer thickness correction term Δh, and obtain the true elevation Htrue of the concrete setting layer. Output the pouring control signal based on the relationship between Htrue and the design elevation Hdes. After the machine stops, it will continue to monitor and generate a quality report, and trigger corresponding early warnings for abnormal signals.

2. The method for laser control of concrete pouring elevation of a cast-in-place pile according to claim 1, characterized in that: In step 1, the gradient pulse cluster laser is formed by modulating the fundamental frequency laser. Each gradient pulse cluster contains 3 pulses, with the pulse amplitude increasing in a gradient ratio of 1:1.5:2 and the pulse interval increasing in a gradient ratio of 0.5μs:1μs:1.5μs.

3. The method for laser control of concrete pouring elevation of a cast-in-place pile according to claim 1, characterized in that: The criteria for determining the three-dimensional recognition coordinate system in step 1 are: the intensity of the frequency harmonic signal ≥ Sth, the polarization rotation angle ≥ θth, and the dielectric relaxation time constant ≥ τth; in Sth≥10 -10 W, θth≥15°, τth≥30 μs; the correction coefficient kτis in the range of 0.98-1.02, and the greater the dielectric relaxation time constant, the closer kτis to 1.

02.

4. The method for laser control of concrete pouring elevation of a cast-in-place pile according to claim 1, characterized in that: In step 3, Δh is calculated as 0.01×(τreal-τth); the true elevation Htrue is calculated as Htrue=kτ×Hgeo-Δh; when Htrue=Hdes-8cm, the system issues a pre-alarm and outputs a deceleration pouring signal; when Htrue=Hdes, the system issues a stop alarm and outputs a shutdown signal, and continues monitoring for 3 minutes after shutdown.

5. A laser measuring and controlling system for the pouring height of a cast-in-place pile concrete, characterized in that, include: Calcium ion temporal coordinated laser emission module: used to emit gradient pulse cluster laser and position the laser spot, including a pulse laser emitter, a calcium ion response enhancement unit and a coaxial positioning light source. The calcium ion response enhancement unit has a built-in lithium borate crystal filter and a concave focusing mirror to modulate the fundamental frequency laser into gradient pulse clusters; Triple signal receiving and analysis module: used to acquire and analyze laser reflection signals, including a frequency doubling signal detection unit, a polarization relaxation co-detection unit and a signal isolation unit. The frequency doubling signal detection unit has a built-in photomultiplier tube and a 266nm narrowband filter. The polarization relaxation co-detection unit includes a Sanjac interferometer and a time-domain response analysis subunit. Triple Coupling Identification and Control Module: Used for interface judgment, elevation correction and early warning, including triple signal coupling processor, elevation correction unit and multi-state early warning unit. The triple signal coupling processor has a built-in three-dimensional threshold model of frequency doubling intensity, polarization angle and dielectric relaxation time.

6. The laser control system for the pouring height of the cast-in-place pile concrete according to claim 5, characterized in that: The pulsed laser emitter is a semiconductor-pumped laser; the coaxial positioning light source uses a visible light LED with a wavelength of 650nm; and the time-domain response analysis subunit has a built-in high-speed sampler.

7. The laser control system for the pouring height of the cast-in-place pile concrete according to claim 5, characterized in that: The signal isolation unit has a built-in dichroic filter and a metal shield to separate ambient stray light from electromagnetic interference signals; the elevation correction unit dynamically calibrates the height value based on the matching degree of the three-dimensional signal; the multi-state early warning unit includes elevation accuracy warning, concrete mix ratio deviation warning, abnormal concrete moisture content warning, insufficient cement dosage warning, and excessive aggregate impurities warning.

8. The laser control system for the pouring height of the cast-in-place pile concrete according to claim 5, characterized in that: The calcium ion time-domain coordinated laser emission module, the triple signal receiving and analysis module, and the triple coupling identification and control module are connected. The triple coupling identification and control module is linked with the pouring equipment and outputs deceleration and shutdown control signals to the pouring equipment.

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