Method and system for nondestructive testing of mass of filling body based on ultrasonic pulse speed

Abstract

The invention provides a nondestructive testing method and system for the quality of a filling body based on ultrasonic pulse speed, and belongs to the technical field of green mining of deep mineral products and quality detection of filling bodies. The system integrates an ultrasonic pulse wave velocity test module, a data processing module, a result output module and an adaptive calibration module which work cooperatively. According to the method, a UCS-UPV power function quantitative model is constructed through a three-factor multi-level test, in-situ-indoor deviation is eliminated in combination with an environment + stress two-dimensional adaptive correction coefficient, and filling body quality grading and evaluation are achieved through on-site ultrasonic detection and strength inversion. According to the method, nondestructive detection is adopted, various stope scenes from shallow parts to deep parts are adapted, a quality control closed loop and a data tracing system can be formed, stope stability and mining safety are effectively guaranteed, and the technical problems that a traditional detection method is high in destructiveness, high in cost and poor in timeliness, and existing ultrasonic detection is insufficient in adaptability and limited in precision are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of green mining of deep minerals and quality testing of backfill bodies, specifically to a non-destructive testing method and system for backfill body quality based on ultrasonic pulse velocity, which is particularly suitable for quality control and engineering safety assessment of tall backfill bodies under high stress in deep environments. Background Technology

[0002] Backfill mining, a core technology for green mining of deep mineral resources, mixes cementing materials with aggregates such as tailings to form backfill bodies. This achieves goaf support, surface subsidence control, and tailings resource utilization. The quality of the backfill body directly determines the stability and safety of the mining area. Backfill body quality testing is a crucial step in ensuring the effectiveness of backfill mining. Traditional testing methods primarily rely on uniaxial compressive strength tests, but these methods have several insurmountable drawbacks. First, traditional methods are destructive, with difficult sampling processes, susceptibility to stress release effects, and results that fail to reflect the overall quality of the backfill body. Second, testing is time-consuming and costly, and real-time monitoring is impossible, failing to meet the timeliness requirements of engineering quality control. Third, for large backfill bodies under high stress at depth, in-situ sampling operations are risky, equipment deployment is difficult, and test results are prone to distortion, making them unsuitable for large-scale engineering applications. The invention patent with publication number CN110068610A provides a method for detecting damage to filling materials based on ultrasonic wave velocity, including the following steps: first, preparing test paste samples according to the proportion of filling material in the field; second, determining the data on the relationship between the load stress σ of the paste sample and the ultrasonic wave velocity V through uniaxial load strength testing; and third, establishing a mathematical model of the damage degree D of the paste sample based on the data of the relationship between σ and V, and calculating the damage degree D of the paste sample through this mathematical model, thereby determining the damage degree of the paste filling material in the field. However, this method does not set an in-situ-indoor adaptation correction mechanism. When testing in deep mining areas (burial depth 1000m, ground temperature 32℃, humidity 85%), the measured UPV value deviates from the true value by 28%, and the inversion strength error exceeds 30%, which cannot meet the engineering accuracy requirements.

[0003] While existing ultrasonic testing technology has the advantage of being non-destructive, its application to infill materials has significant limitations: First, it has not systematically revealed the synergistic influence of key factors such as cement-sand ratio, curing age, and mass concentration on ultrasonic pulse velocity (UPV) and intensity, resulting in a lack of specificity in the testing parameters; second, it has not established a high-precision UCS-UPV quantitative relationship model, making it impossible to accurately invert mechanical properties; and third, it ignores the differences between in-situ infill materials and laboratory specimens in terms of curing environment, stress state, and structural scale, lacking an effective testing adaptation mechanism, leading to insufficient reliability of the test results and limiting its engineering application in the quality testing of deep infill materials.

[0004] Therefore, there is an urgent need to develop a non-destructive testing technology that can accurately correlate ultrasonic parameters with the mechanical properties of filling materials and is suitable for complex deep working conditions. This technology would solve the problems of traditional testing methods being highly destructive, costly, and inefficient, and would enable comprehensive, rapid, and accurate control of filling material quality, providing technical support for green mining of deep mineral resources. Summary of the Invention

[0005] In view of the technical problems existing in the background art, the present invention provides a non-destructive testing method and system for filling quality based on ultrasonic pulse velocity. It reveals the influence of cement-sand ratio, age, and mass concentration on the UPV and strength of filling through the system, and constructs a high-precision UCS-UPV quantification model; establishes an in-situ-indoor ex-situ testing adaptation mechanism to eliminate the testing deviation caused by environmental factors, stress and other factors; and integrates an ultrasonic testing module, a data processing module and a result output module to form an integrated testing system, realizing non-destructive, rapid and accurate evaluation of filling quality, and effectively solving the problem of deep filling quality testing.

[0006] In a first aspect, embodiments of the present invention provide a non-destructive testing method for the quality of filling materials based on ultrasonic pulse velocity, comprising: S1, Indoor benchmark model construction: Select the same raw materials as the on-site filling project, and prepare standard specimens of filling bodies with different ratios and ages through multi-factor and multi-level tests; measure the ultrasonic pulse velocity (UPV) and uniaxial compressive strength (UCS) of each specimen, and construct a UCS-UPV quantitative model to characterize the correlation between UCS and UPV. S2, In-situ-indoor adaptation calibration: Measure the in-situ environmental parameters and stress parameters of the in-situ filling body, calculate the adaptation coefficient used to correct the ultrasonic pulse velocity, and construct an in-situ adaptation correction algorithm for correcting the measured field UPV data. S3, On-site non-destructive testing: Set up measuring points on the surface of the in-situ filling body on-site, collect on-site UPV data, remove abnormal data, and use the in-situ adaptation correction algorithm obtained in step S2 to correct the on-site UPV data to obtain the corrected UPV data. S4, Quality Assessment: Substitute the UPV data corrected in step S3 into the UCS-UPV quantization model constructed in step S1 to obtain the uniaxial compressive strength (UCS) of the in-situ filling body. Based on the UCS inversion data, classify the quality grade of the filling body and generate a test report.

[0007] As a further improvement of the present invention, in step S1, the UCS-UPV quantization model is a power function model, expressed as: UCS = 1×10^ -8 × UPV 2.7112 The goodness of fit R² ≥ 0.94.

[0008] As a further improvement of the present invention, in step S1, multiple factors include ash-sand ratio, curing age and mass concentration; the specimen is a cylinder, and standard curing conditions are adopted: temperature 20±2℃, humidity ≥95%, curing age 3~28d; the raw materials include tailings and slag-based binder, with an ash-sand ratio ranging from 1:4 to 1:12 and a mass concentration ranging from 66% to 72%.

[0009] As a further improvement of the present invention, in step S2, the adaptation coefficient includes a temperature adaptation coefficient K. t Humidity adaptability coefficient K h And confining pressure fit coefficient K σ ; The in-situ adaptation correction algorithm is: UPV 修 = UPV 原 ×K t ×K h ×K σ ; Among them, UPV 原 UPV data from the site; UPV 修 This is the corrected UPV data.

[0010] As a further improvement of the present invention, the temperature adaptation coefficient K t = T1 / 20; where T1 is the in-situ measured ground temperature and 20 is the standard curing temperature; The humidity adaptation coefficient K h = 1 - 0.01×(95 - H1); where H1 is the in-situ measured humidity and 95 is the standard curing humidity; The confining pressure adaptation coefficient K σ = UPV σ / UPV0; where UPV σ UPV0 is the ultrasonic pulse velocity of the indoor specimen under equivalent confining pressure, and UPV0 is the ultrasonic pulse velocity of the indoor specimen without confining pressure. The equivalent confining pressure is calculated based on the burial depth of the in-situ filling body. The confining pressure σ = 0.025 × burial depth of the filling body, MPa.

[0011] As a further improvement of the present invention, in step S3, the specific process of the on-site non-destructive testing includes: applying coupling agent to each measuring point, using an ultrasonic transducer for measurement, recording the ultrasonic propagation distance L and propagation time Δt, and calculating the UPV. 原 = L / Δt; and perform multiple measurements at the same measuring point, discarding outliers with deviations exceeding 5% and taking the average value.

[0012] Secondly, embodiments of the present invention provide a non-destructive testing system for filling quality based on ultrasonic pulse velocity, which is used to perform the above-described non-destructive testing method for filling quality based on ultrasonic pulse velocity, including: The ultrasonic pulse velocity testing module is used to collect ultrasonic pulse velocity (UPV) data of in-situ filling materials and standard filling material specimens. The data processing module, connected to the ultrasonic pulse velocity testing module, is used to store the UCS-UPV quantization model, the adaptation coefficient algorithm module, and the in-situ adaptation correction algorithm module, and to perform ultrasonic pulse velocity calculation, data correction, and intensity inversion. An adapter calibration module is connected to the data processing module to simulate in-situ and stress environments; The results output module, connected to the data processing module, is used to display and output the test results, including corrected UPV data, UCS inversion data, quality grade, and test report.

[0013] As a further improvement of the present invention, the ultrasonic pulse velocity testing module includes a signal generator, at least one pair of ultrasonic transducers and a signal receiver; the frequency range of the ultrasonic transducers is 10~50kHz; the output voltage of the signal generator is ±14V, the sampling frequency of the signal receiver is ≥2000kHz, and the resolution is ≤0.1μs.

[0014] As a further improvement of the present invention, the adaptation calibration module includes a temperature / humidity control unit and a confining pressure loading unit, used to simulate the temperature, humidity and confining pressure environment of the in-situ filling body indoors to obtain the temperature adaptation coefficient K. t Humidity adaptability coefficient K h Confining pressure adaptation coefficient K σ The temperature / humidity control unit adjusts the temperature range to 15~40℃ with an accuracy of ±0.5℃; the humidity adjustment range is 60%~95% with an accuracy of ±2%; the confining pressure loading unit has a loading range of 0~10MPa with an accuracy of ±0.1MPa.

[0015] As a further improvement of the present invention, it is applicable to the detection of filling bodies with a size of φ50mm×100mm and above in shallow to deep mining areas, with a UPV detection range of 700~2600m / s, an inversion UCS range of 0.4~9.5MPa, and a relative error of ≤15%; it realizes the whole process quality control of "detection-inversion-grading-early warning" and supports the connection with the mining GIS system to form a spatiotemporal database.

[0016] Compared with the prior art, the present invention has the following significant advantages: 1. Non-destructive testing, comprehensive and accurate: No sampling or destruction is required, and the overall quality of the filling body can be tested, avoiding the defects of traditional methods that "substitute points for the whole"; the UCS-UPV quantization model has a goodness of fit of 0.9467 and the relative error of inversion intensity is ≤12.87%, with high detection accuracy.

[0017] 2. High efficiency and low cost: The detection time for a single point is ≤3 minutes, which is more than 80% more efficient than traditional methods; the detection cost is reduced by 90%, and there is no need for complicated sampling and maintenance procedures, which greatly reduces the cost of project management.

[0018] 3. Strong adaptability and wide range of applications: Through the in-situ-indoor adaptation calibration mechanism, it can be adapted to the detection of filling bodies under different depths, temperatures and stress conditions, covering various mining scenarios from shallow to deep.

[0019] 4. Closed-loop quality control: It realizes the whole process of "non-destructive testing → strength inversion → quality classification → risk warning", and can identify unqualified areas (such as UCS<3MPa) in real time, guide the grouting treatment, and reduce the risk of mine collapse. 5. Data traceability: The detection data is automatically stored and associated with the coordinates of the measuring points, and supports the connection with the mine GIS system to form a two-dimensional "time-space" database of the filling quality, which facilitates later traceability and optimization.

[0020] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0021] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the present invention will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0022] Figure 1 This is a schematic flowchart of the non-destructive testing method for filling quality based on ultrasonic pulse velocity provided in an embodiment of the present invention. Detailed Implementation

[0023] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the invention, are intended to cover non-exclusive inclusion.

[0025] In the description of the embodiments of this invention, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this invention, "multiple" means two or more, unless otherwise explicitly defined.

[0026] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0027] In the description of the embodiments of this invention, the term "and / or" is merely a description of the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following associated objects have an "or" relationship.

[0028] In the description of the embodiments of the present invention, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more (including two groups), and "multiple pieces" refers to two or more (including two pieces).

[0029] In the description of the embodiments of the present invention, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0030] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0031] To address the problems of traditional infill quality testing methods being highly destructive, costly, and time-consuming, as well as the insufficient adaptability and limited accuracy of existing ultrasonic testing technologies, this invention provides a non-destructive testing method and system for infill quality based on ultrasonic pulse velocity. By establishing a dual mechanism combining an "indoor benchmark model" and "in-situ environmental adaptation calibration," it achieves non-destructive testing of infill quality from indirect measurement to precise inversion. Specifically, firstly, a high-precision power function quantification model of the ultrasonic pulse velocity (UPV) and uniaxial compressive strength (UCS) of the infill is constructed in a laboratory system. Secondly, adaptation coefficients based on temperature, humidity, and in-situ confining pressure are introduced to correct the measured UPV values ​​in the field, thereby eliminating systematic errors caused by differences between in-situ and laboratory conditions. Ultimately, this achieves rapid, low-cost, and high-precision non-destructive assessment of infill strength in deep and complex environments, significantly improving the efficiency of engineering quality control.

[0032] This invention provides a non-destructive testing system for filling quality based on ultrasonic pulse velocity. It is used to perform a non-destructive testing method for filling quality based on ultrasonic pulse velocity, and includes an ultrasonic pulse velocity testing module, a data processing module, a result output module, and an adaptation calibration module. The modules interact with each other via the RS485 protocol, with a response delay ≤100ms. By integrating ultrasonic testing, data processing, result output, and adaptation calibration modules, it achieves integrated detection, analysis, and evaluation, improving detection efficiency and reliability.

[0033] The ultrasonic pulse velocity (UPV) testing module is used to collect ultrasonic pulse velocity data of the in-situ filling body and standard filling body specimens. Specifically, the ultrasonic pulse velocity testing module includes two multi-frequency ultrasonic transducers (50mm in diameter, frequency range 10-50kHz, optimal excitation frequency 20kHz), a signal generator (output voltage ±14V, waveform is sine wave), and a signal receiver (sampling frequency 2000kHz, resolution 0.1μs), used to measure the ultrasonic propagation time Δt and propagation distance L.

[0034] The data processing module, connected to the ultrasonic pulse velocity testing module, is used to store the UCS-UPV quantization model, the adaptation coefficient algorithm module, and the in-situ adaptation correction algorithm module, and to perform ultrasonic pulse velocity calculation, data correction, and intensity inversion. The data processing module uses an industrial-grade microcontroller (model STM32F407), with a built-in UCS-UPV quantization model and adaptation coefficient algorithm, a data processing speed ≥10 sets / s, and a storage capacity ≥100,000 test records.

[0035] The adaptation calibration module, connected to the data processing module, is used to simulate in-situ and stress environments. The adaptation calibration module includes a temperature / humidity control unit (temperature adjustment range 15-40℃, accuracy ±0.5℃; humidity adjustment range 60%~95%, accuracy ±2%) and a confining pressure loading unit (loading range 0-10MPa, accuracy ±0.1MPa).

[0036] The result output module, connected to the data processing module, is used to display and output the test results, including corrected UPV data, UCS inversion data, quality grade, and test report. The result output module includes a 7-inch touchscreen (1280×720 resolution) and an SD card storage unit, which can display UPV values, inversion intensity, and quality grade in real time, and supports data export in Excel format.

[0037] This invention also provides a non-destructive testing method for the quality of fillings based on ultrasonic pulse velocity, which, based on the above-mentioned non-destructive testing system, includes the following steps: S1, Indoor Benchmark Model Construction: Using materials consistent with those used in the on-site filling project, standard specimens of filling bodies with different proportions and ages were prepared through multi-factor, multi-level experiments. The ultrasonic pulse velocity (UPV) and uniaxial compressive strength (UCS) of each specimen were measured, and a UCS-UPV quantitative model characterizing the correlation between UCS and UPV was constructed. Specific procedures are as follows: ① Raw material matching: Select tailings and slag-based binders (P) consistent with the project. O 42.5), designed a three-factor multi-level test (Table 1); using the three-factor collaborative modeling method, through multi-level tests with a cement-sand ratio of 1:12~1:4, an age of 3~28d, and a mass concentration of 66%~72%, a benchmark model for the entire life cycle of the strength development of the cover filling body was constructed to ensure adaptability under different working conditions; ② Specimen preparation: Prepare cylindrical specimens with a diameter of φ50mm×100mm according to the specified ratio, and cure under standard conditions (20±2℃, humidity ≥95%) until the corresponding age; ③ Data Acquisition: The ultrasonic pulse velocity (UPV) was measured using an ultrasonic pulse velocity testing module, and the compressive strength (UCS) was measured using a press (loading rate 0.1 mm / min). Based on 120 sets of valid data, a power function model was constructed: UCS = 1 × 10⁻⁶. -8 ×UPV 2.7112 (R²=0.9467).

[0038] Table 1. Typical sample of 120 valid data sets (covering all factor levels) S2, In-situ-Indoor Adaptation Calibration: This involves measuring the in-situ environmental and stress parameters of the in-situ filling material, calculating the adaptation coefficient used to correct the ultrasonic pulse velocity, and constructing an in-situ adaptation correction algorithm to correct the measured field UPV data. The specific operation is as follows: ① Environmental adaptation: Measure the in-situ ground temperature T1 and humidity H1, and calculate the adaptation coefficient K. t = T1 / 20 (standard temperature 20℃), K h = 1-0.01×(95-H1); where T1 is the in-situ measured ground temperature, 20 is the standard curing temperature; H1 is the in-situ measured humidity, and 95 is the standard curing humidity; ② Stress adaptation: Calculate the in-situ confining pressure σ (σ=0.025×burial depth, unit MPa) based on the burial depth, and measure the UPV correction factor K after applying the equivalent confining pressure. σ = UPV σ / UPV0 (UPV σ UPVσ is the ultrasonic pulse velocity under confining pressure, and UPV0 is the ultrasonic pulse velocity without confining pressure. ③ Comprehensive Correction: The in-situ adaptation correction algorithm is: UPV 修 = UPV 原 ×K t ×K h ×K σ ; Among them, UPV 原 UPV data from the site; UPV 修 This is the corrected UPV data.

[0039] The in-situ adaptation correction algorithm establishes an adaptation coefficient K=K based on the dual dimensions of "environment (T / H) + stress (σ)". t ×K h ×K σ K t = In-situ temperature / 20 K h =1-0.01×(95 - in-situ humidity), K σ =UPV under confining pressure / UPV without confining pressure, accurately eliminating in-situ-indoor deviation.

[0040] The ultrasonic propagation characteristics and mechanical properties of the filling material are determined by the density of its internal structure, following the core principle of "solid medium dominates conduction, while fluid (water / air) degrades conduction": Microscopic mechanism: Natural infill contains tailings particles (solid), hydration products (CSH gel), and pores (water / air); the propagation speed of ultrasonic pulses in solids (3000-5000m / s) is much higher than that in fluids (1500m / s in water and 340m / s in air), so the higher the proportion of solids, the greater the UPV; Strength Correlation: The three-dimensional network structure formed by CSH gel is the core source of strength. Increased UPV means increased gel content, reduced porosity, denser structure, more uniform stress transmission, and consequently, improved UCS. Adaptation correction: In deep in-situ environments, confining pressure will compress porosity (increase UPV) and ground temperature will accelerate hydration (increase UPV). Adaptation coefficient correction is required to ensure the consistency between the indoor model and the in-situ structure.

[0041] S3, Non-destructive testing: Measurement points are set up on the surface of the in-situ filling body to collect on-site UPV data. Abnormal data is removed, and the on-site UPV data is corrected using the in-situ adaptation correction algorithm obtained in step S2, resulting in corrected UPV data. The specific operation is as follows: ① Measurement point layout: Set up measurement points in a 5m×5m grid. Wipe the surface of each measurement point with a dry cloth and apply Vaseline coupling agent (0.5-1mm thick). ② Wave velocity measurement: Place the transducer close to the measuring point (align the axis), record the propagation distance L (accuracy ±0.1mm) and propagation time Δt (take the average of 3 measurements), and calculate UPV=L / Δt; ③ Anomaly removal: When the deviation of a single measurement from the average value exceeds 5%, the measurement is repeated (excluding interference from bubbles and cracks).

[0042] S4, Quality Assessment: Substitute the UPV data corrected in step S3 into the UCS-UPV quantization model constructed in step S1 to obtain the uniaxial compressive strength (UCS) of the in-situ filling. Based on the UCS inversion data, classify the quality grade of the filling and generate a test report. The specific operation is as follows: ① Intensity inversion: Substitute the corrected UPV data into the model to calculate and invert the UCS data; ② Quality grading: Grades are determined according to engineering standards (Excellent: UCS≥8MPa; Good: 5≤UCS<8MPa; Pass: 3≤UCS<5MPa; Unpass: UCS<3MPa). ③ Report generation: Outputs an inspection report containing measurement point coordinates, corrected UPV, inverted UCS, and quality grade.

[0043] Table 2 Summary of Three-Factor Multilevel Experimental Design and Core Influence Magnitude To verify the technical effectiveness of this invention, four sets of embodiments (different engineering scenarios) and three sets of comparative examples (traditional uniaxial compressive strength testing methods) were set up to compare the testing accuracy, cost, and efficiency. The test results are as follows: Example 1 Embodiment 1 of this invention provides a non-destructive testing method for backfill quality based on ultrasonic pulse velocity, for testing backfill in deep mining areas (cement-sand ratio 1:4, age 28 days, mass concentration 72%). The testing process is as follows: S1, Indoor benchmark model construction: Using materials consistent with those used in the on-site filling project, standard specimens of the filling body were prepared through a multi-factor, multi-level test (cement-sand ratio 1:4, age 28 days, mass concentration 72%); a power function model was constructed: UCS = 1 × 10⁻⁶. -8 ×UPV 2.7112 (R²=0.9467).

[0044] S2, In-situ-indoor adaptation calibration: Measure the in-situ environmental and stress parameters of the in-situ filling material, calculate the adaptation coefficient used to correct the ultrasonic pulse velocity, and construct an in-situ adaptation correction algorithm to correct the measured field UPV data; specifically, perform in-situ-indoor adaptation calibration (ambient temperature 25℃, ambient humidity 85%, equivalent confining pressure 0.5MPa); calculate the adaptation coefficient K. t =25 / 20=1.25、K h =1-0.01×(95-85)=0.9、K σ =1.05 (UPV under confining pressure / UPV without confining pressure), construct in-situ adaptation correction algorithm: UPV 修 = UPV 原 ×1.25×0.9×1.05.

[0045] S3, On-site Non-destructive Testing: Measurement points are set up on the surface of the in-situ backfill to collect on-site UPV data. Abnormal data is removed, and the on-site UPV data is corrected using the in-situ adaptation correction algorithm obtained in step S2, resulting in corrected UPV data. Specifically, an ultrasonic pulse velocity testing module is used to test five points on the in-situ backfill in the mining area. The corrected UPV data is then substituted into a quantization model to invert the intensity. For example: the average on-site UPV is 2020 m / s; after removing abnormal data and correcting, the UPV is obtained. 修 = 2020×1.25×0.9×1.05=2399m / s S4, Quality Assessment: Substitute the UPV data corrected in step S3 into the UCS-UPV quantization model constructed in step S1, and the uniaxial compressive strength UCS of the in-situ filling body is obtained as 9.32 MPa. Based on the UCS inversion data, the quality grade of the filling body is classified as "Excellent".

[0046] Performance testing: On-site destructive testing intensity was 9.38 MPa (Comparative Example 1), with a relative error of 0.64%; single-point testing time was 3 minutes, and the testing cost was 80 yuan per point.

[0047] Example 2 Embodiment 2 of this invention provides a non-destructive testing method for backfill quality based on ultrasonic pulse velocity, for testing backfill in medium-depth mining areas (cement-sand ratio 1:8, age 14 days, mass concentration 70%). The testing process is as follows: S1, Indoor benchmark model construction: Using materials consistent with those used in the on-site filling project, standard specimens of the filling body were prepared through a multi-factor, multi-level test (cement-sand ratio 1:8, age 14 days, mass concentration 70%). A power function model was constructed: UCS = 1 × 10⁻⁶. -8 ×UPV 2.7112 (R²=0.9467).

[0048] S2, In-situ-indoor adaptation calibration: Measure the in-situ environmental and stress parameters of the in-situ filling material, calculate the adaptation coefficient used to correct the ultrasonic pulse velocity, and construct an in-situ adaptation correction algorithm to correct the measured field UPV data; specifically, perform in-situ-indoor adaptation calibration (ambient temperature 22℃, ambient humidity 80%, equivalent confining pressure 0.3MPa); calculate the adaptation coefficient K. t =22 / 20=1.1、K h =1-0.01×(95-80)=0.85、K σ =1.03, construct the in-situ adaptation correction algorithm: UPV 修 = UPV 原 ×1.1×0.85×1.03.

[0049] S3, On-site Non-destructive Testing: Measurement points are set up on the surface of the in-situ backfill to collect on-site UPV data. Abnormal data is removed, and the on-site UPV data is corrected using the in-situ adaptation correction algorithm obtained in step S2, resulting in corrected UPV data. Specifically, an ultrasonic pulse velocity testing module is used to test six points on the in-situ backfill in the mining area. The corrected UPV data is then substituted into a quantization model to invert the intensity. For example: the average on-site UPV is 1575 m / s; after removing abnormal data and correcting, the UPV is obtained... 修 = 1575×1.1×0.85×1.03=1452m / s.

[0050] S4, Quality Assessment: Substitute the UPV data corrected in step S3 into the UCS-UPV quantization model constructed in step S1, and the uniaxial compressive strength UCS of the in-situ filling body is obtained as 5.23 MPa. Based on the UCS inversion data, the quality grade of the filling body is classified as "good".

[0051] Performance testing: Sampling destructive testing intensity 5.44MPa (Comparative Example 2), relative error 3.86%; single-point testing time 2.5min, testing cost 75 yuan / point.

[0052] Example 3 Embodiment 3 of this invention provides a non-destructive testing method for backfill quality based on ultrasonic pulse velocity, for testing backfill in shallow mining areas (cement-sand ratio 1:12, age 7 days, mass concentration 68%). The testing process is as follows: S1, Indoor benchmark model construction: Using materials consistent with those used in the on-site filling project, standard specimens of the filling body were prepared through a multi-factor, multi-level test (cement-sand ratio 1:12, age 7 days, mass concentration 68%). A power function model was constructed: UCS = 1 × 10⁻⁶. -8 ×UPV 2.7112 (R²=0.9467).

[0053] S2, In-situ-indoor adaptation calibration: In-situ environmental and stress parameters of the in-situ filling body are measured, and the adaptation coefficient used to correct the ultrasonic pulse velocity is calculated. An in-situ adaptation correction algorithm is constructed to correct the measured field UPV data. Specifically, in-situ-indoor adaptation calibration is performed (ambient temperature 20℃, ambient humidity 75%, equivalent confining pressure 0.1MPa); the adaptation coefficient K is calculated. t =20 / 20=1.0、K h =1-0.01×(95-75)=0.8、K σ =1.01, construct the in-situ adaptation correction algorithm: UPV 修 = UPV 原 ×1.0×0.8×1.01.

[0054] S3, On-site Non-destructive Testing: Measurement points are set up on the surface of the in-situ backfill to collect on-site UPV data. Abnormal data is removed, and the on-site UPV data is corrected using the in-situ adaptation correction algorithm obtained in step S2, resulting in corrected UPV data. Specifically, an ultrasonic pulse velocity testing module is used to test four points on the in-situ backfill in the mining area. The corrected UPV data is then substituted into a quantization model to invert the intensity. For example: the average on-site UPV is 1047 m / s; after removing abnormal data and correcting, the UPV is obtained. 修 = 1047×1.0×0.8×1.01=846m / s.

[0055] S4, Quality Assessment: Substitute the UPV data corrected in step S3 into the UCS-UPV quantization model constructed in step S1, and the uniaxial compressive strength UCS of the in-situ filling body is obtained as 1.37MPa. Based on the UCS inversion data, the quality grade of the filling body is classified as "qualified".

[0056] Performance testing: Sampling destructive testing intensity 1.40MPa (comparative example 3), relative error 2.14%; single-point testing time 2min, testing cost 70 yuan / point.

[0057] Example 4 Test scenario: Same as Example 1 (deep mining area, burial depth 1000m, ground temperature 25℃, humidity 85%, confining pressure 0.5MPa). Detection method: Using existing ultrasonic testing technology (without temperature / humidity / containing pressure adaptation correction), the on-site UPV data of 2020 m / s was directly collected and substituted into the UCS-UPV quantization model of this embodiment to invert the intensity; Performance testing: The inversion intensity was 11.2 MPa, with a relative error of 20.5% compared to the sampling detection intensity of 9.38 MPa, which far exceeds the engineering allowable error (≤15%). After using the adaptation correction of this patent, the error was reduced to 0.64%, highlighting the necessity of the correction mechanism.

[0058] Comparative Examples 1-3 Comparative Examples 1-3 employed the traditional uniaxial compressive strength testing method. The testing process is as follows: Samples were taken from the filling bodies of Examples 1-3 above (3 specimens per group), and compressive strength tests were conducted after standard curing.

[0059] Performance tests of Comparative Examples 1-3: As shown in Table 2, the test results deviated from the ultrasonic test inversion results by ≤4%; however, the single-group test cycle was 28 days (including curing), the cost of a single-point test was 800 yuan, and the sampling and testing time was ≥4 hours per point; the specimens were destroyed after the test, which could not reflect the overall quality of the filling body.

[0060] Table 3 Performance Comparison in Different Detection Scenarios (Example vs. Comparative Example) The data above shows that the deviation between the ultrasonic inversion intensity obtained from all embodiments and the traditional destructive testing results is ≤4%, and the goodness of fit R² = 0.9467, proving that the detection accuracy of the present invention meets engineering requirements. The detection efficiency of the present invention is more than 80% higher than that of traditional methods, the detection cost is reduced by 90%, and it is a non-destructive test that can achieve multi-point, full-coverage detection, avoiding the limitation of the traditional method of "substituting points for areas". Through the adaptation calibration module, the detection system can be adapted to the detection of fillings under different depths and environmental conditions, with strong adaptability, solving the problem of insufficient adaptability of existing ultrasonic testing technology.

[0061] This invention constructs an integrated non-destructive testing technology system encompassing indoor benchmark modeling, in-situ adaptation calibration, and testing. A high-precision UCS-ultrasonic pulse velocity (UPV) power function quantization model is established through multi-level experiments considering three factors: sand-cement ratio, age, and mass concentration. This model is combined with a dual-dimensional adaptation correction coefficient (K=K) based on environmental factors (temperature, humidity) and stress (confining pressure). t ×K h ×Kσ) eliminates in-situ-indoor deviation, integrates ultrasonic testing, data processing, result output and adaptation calibration modules to form an integrated system, realizes non-destructive, rapid (single point ≤3min), accurate (relative error ≤4%) detection and strength inversion of filling quality, covers various mining scenarios from shallow to deep, and constructs a closed loop of quality control of detection-evaluation-early warning.

[0062] In summary, this invention provides a non-destructive testing method and system for filling body quality based on ultrasonic pulse velocity, belonging to the technical field of green mining and filling body quality testing in deep mineral resources. The system integrates an ultrasonic pulse velocity testing module, a data processing module, a result output module, and an adaptation calibration module, with each module working collaboratively. The method constructs a UCS-UPV power function quantization model through a three-factor multi-level experiment, and eliminates in-situ-indoor deviations by combining an "environment + stress" dual-dimensional adaptation correction coefficient. Filling body quality grading and evaluation are achieved through on-site ultrasonic testing and strength inversion. This invention is a non-destructive testing method, adaptable to various mining scenarios from shallow to deep, and can form a closed-loop quality control and data traceability system, effectively ensuring mining stability and safety. It effectively solves the technical problems of traditional testing methods being highly destructive, costly, and inefficient, as well as the insufficient adaptability and limited accuracy of existing ultrasonic testing methods.

[0063] It should be noted that the present invention is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments that have the same structure and perform the same effects as the technical concept within the scope of the present invention are included within the scope of the present invention. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of the present invention, are also included within the scope of the present invention.

Claims

1. A non-destructive testing method for the quality of fillings based on ultrasonic pulse velocity, characterized in that, include: S1, Indoor benchmark model construction: Select the same raw materials as the on-site filling project, and prepare standard specimens of filling bodies with different ratios and ages through multi-factor and multi-level tests; measure the ultrasonic pulse velocity (UPV) and uniaxial compressive strength (UCS) of each specimen, and construct a UCS-UPV quantitative model. S2, In-situ-indoor adaptation calibration: Measure the in-situ environmental parameters and stress parameters of the in-situ filling body, calculate the adaptation coefficient used to correct the ultrasonic pulse velocity, and construct an in-situ adaptation correction algorithm for correcting the measured field UPV data. S3, On-site non-destructive testing: Set up measuring points on the surface of the in-situ filling body on-site, collect on-site UPV data, remove abnormal data, and use the in-situ adaptation correction algorithm obtained in step S2 to correct the on-site UPV data to obtain the corrected UPV data. S4, Quality Assessment: Substitute the UPV data corrected in step S3 into the UCS-UPV quantization model constructed in step S1 to obtain the uniaxial compressive strength (UCS) of the in-situ filling body. Based on the UCS inversion data, classify the quality grade of the filling body and generate a test report.

2. The non-destructive testing method for the quality of fillings based on ultrasonic pulse velocity according to claim 1, characterized in that, In step S1, the UCS-UPV quantization model is a power function model, expressed as: UCS = 1×10^ -8 ×UPV 2.7112 The goodness of fit R² ≥ 0.

94.

3. The non-destructive testing method for the quality of fillings based on ultrasonic pulse velocity according to claim 1, characterized in that, In step S1, multiple factors include the ash-sand ratio, curing age, and mass concentration; the specimen is a cylinder, and standard curing conditions are adopted: temperature 20±2℃, humidity ≥95%, curing age 3~28d; the raw materials include tailings and slag-based binder, with an ash-sand ratio ranging from 1:4 to 1:12 and a mass concentration ranging from 66% to 72%.

4. The non-destructive testing method for the quality of fillings based on ultrasonic pulse velocity according to claim 2, characterized in that, In step S2, the adaptation coefficient includes the temperature adaptation coefficient K. t Humidity adaptability coefficient K h And confining pressure fit coefficient K σ ; The in-situ adaptation correction algorithm is: UPV 修 = UPV 原 ×K t ×K h ×K σ ; Among them, UPV 原 UPV data from the site; UPV 修 This is the corrected UPV data.

5. The non-destructive testing method for the quality of filling materials based on ultrasonic pulse velocity according to claim 4, characterized in that, The temperature adaptation coefficient K t = T1 / 20; where T1 is the in-situ measured ground temperature and 20 is the standard curing temperature; The humidity adaptation coefficient K h = 1 - 0.01×(95 - H1); where H1 is the in-situ measured humidity and 95 is the standard curing humidity; The confining pressure adaptation coefficient K σ = UPV σ / UPV0; where UPV σ UPV0 is the ultrasonic pulse velocity of the indoor specimen under equivalent confining pressure, and UPV0 is the ultrasonic pulse velocity of the indoor specimen without confining pressure. The equivalent confining pressure is calculated based on the burial depth of the in-situ filling body. The confining pressure σ = 0.025 × burial depth of the filling body, MPa.

6. The non-destructive testing method for the quality of fillings based on ultrasonic pulse velocity according to claim 4, characterized in that, In step S3, the specific process of the on-site non-destructive testing includes: applying coupling agent to each measuring point, using an ultrasonic transducer for measurement, recording the ultrasonic propagation distance L and propagation time Δt, and calculating the UPV. 原 = L / Δt; and perform multiple measurements at the same measuring point, discarding outliers with deviations exceeding 5% and taking the average value.

7. A non-destructive testing system for the quality of fillings based on ultrasonic pulse velocity, characterized in that, A method for performing a non-destructive testing of filling material quality based on ultrasonic pulse velocity as described in any one of claims 1-6, comprising: The ultrasonic pulse velocity testing module is used to collect ultrasonic pulse velocity (UPV) data of in-situ filling materials and standard filling material specimens. The data processing module, connected to the ultrasonic pulse velocity testing module, is used to store the UCS-UPV quantization model, the adaptation coefficient algorithm module, and the in-situ adaptation correction algorithm module, and to perform ultrasonic pulse velocity calculation, data correction, and intensity inversion. An adapter calibration module is connected to the data processing module to simulate in-situ and stress environments; The results output module, connected to the data processing module, is used to display and output the test results, including corrected UPV data, UCS inversion data, quality grade, and test report.

8. The non-destructive testing system for filling quality based on ultrasonic pulse velocity according to claim 7, characterized in that, The ultrasonic pulse velocity testing module includes a signal generator, at least one pair of ultrasonic transducers, and a signal receiver; the frequency range of the ultrasonic transducers is 10~50kHz; the output voltage of the signal generator is ±14V, the sampling frequency of the signal receiver is ≥2000kHz, and the resolution is ≤0.1μs.

9. The non-destructive testing system for filling quality based on ultrasonic pulse velocity according to claim 7, characterized in that, The adaptation calibration module includes a temperature / humidity control unit and a confining pressure loading unit, used to simulate the temperature, humidity, and confining pressure environment of the in-situ filling material indoors to obtain the temperature adaptation coefficient K. t Humidity adaptability coefficient K h Confining pressure adaptation coefficient K σ The temperature / humidity control unit has a temperature adjustment range of 15~40℃ and an accuracy of ±0.5℃; a humidity adjustment range of 60%~95% and an accuracy of ±2%; and a confining pressure loading unit has a loading range of 0~10MPa and an accuracy of ±0.1MPa.

10. The method for non-destructive testing of filling quality based on ultrasonic pulse velocity according to any one of claims 1-6, or the application of the non-destructive testing system for filling quality based on ultrasonic pulse velocity according to any one of claims 7-9, characterized in that, It is suitable for detecting filling bodies with dimensions of φ50mm×100mm and above in shallow to deep mining areas. The UPV detection range is 700~2600m / s, the inverted UCS data range is 0.4~9.5MPa, and the relative error is ≤15%.

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