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CN-122017024-A - Surface survey method and device for building cracks

CN122017024ACN 122017024 ACN122017024 ACN 122017024ACN-122017024-A

Abstract

The invention is suitable for the technical field of nondestructive testing of building structures, and provides a surface surveying method and device for building cracks, wherein the surface surveying method for building cracks comprises the following steps of constructing a physical property evaluation model of a tested material according to the water-cement ratio, the water content and the minimum steel bar clearance of the tested material, and outputting a physical property index of the material; and constructing an actual measurement quality assessment model according to the coupling uniformity between the current ultrasonic probe and the concrete surface, the signal-to-noise ratio of the actual measurement signal and the waveform definition, and outputting an actual measurement credibility index. The surface survey method of the building cracks provided by the invention forms a closed loop feedback mechanism through quantification of material characteristics, prediction of expected accuracy, evaluation of measured quality and intelligent adjustment of probe frequency.

Inventors

  • LI XIANCAI
  • LIANG ZHITING
  • Lin Muzhen

Assignees

  • 广东美霖建设集团有限公司

Dates

Publication Date
20260512
Application Date
20260227

Claims (9)

  1. 1. A method of surface survey of a crack in a building, comprising the steps of: s1, constructing a measured material physical property evaluation model according to the water-cement ratio, the water content and the minimum steel bar clearance of the measured material, and outputting a material physical property index; S2, constructing an expected accuracy evaluation model according to the physical property index of the material and the probe frequency of the current ultrasonic probe, and outputting an expected accuracy index; s3, constructing an actual measurement quality evaluation model according to the coupling uniformity, the actual measurement signal-to-noise ratio and the waveform definition between the current ultrasonic probe and the concrete surface, and outputting an actual measurement credibility index; and S4, constructing a probe frequency adjustment model according to the current probe frequency, the stability of the probe signal and the expected accuracy index, and outputting the target probe frequency.
  2. 2. The method of surface surveying of a crack of a building according to claim 1, wherein in the measured material physical property evaluation model of step S1: Substituting the water-cement ratio, the water content and the minimum steel bar clearance of the measured materials into a maximum-minimum value normalization formula in sequence for processing, and generating a water-cement ratio index, a water content index and a minimum steel bar spacing index in sequence; And multiplying the water-cement ratio index, the complement number of the water content index (the value obtained by subtracting the corresponding index from 1) and the complement number of the minimum steel bar spacing index by corresponding preset weight coefficients respectively, then carrying out weighted summation, and then carrying out power operation of a nonlinear adjusting factor to obtain the material physical property index.
  3. 3. The method of surface surveying of a building crack according to claim 2, wherein in the expected accuracy assessment model of step S2: Substituting the probe frequency of the current ultrasonic probe into a maximum-minimum value normalization formula for processing, and generating a probe frequency index; multiplying the material physical property index by a linear combination to obtain an expected accuracy index; the linear combination is obtained by multiplying a preset frequency adjustment intensity coefficient by a probe frequency index and the complement thereof and adding a preset basic accuracy coefficient.
  4. 4. The method of surface surveying of a building crack according to claim 1, wherein in the measured quality assessment model of step S3: Substituting the coupling uniformity, the signal-to-noise ratio of the actual measured signal and the waveform definition between the current ultrasonic probe and the concrete surface into a maximum-minimum normalization formula in sequence for processing, and generating a coupling uniformity index, a signal-to-noise ratio index and a waveform definition index in sequence; The coupling uniformity index, the signal-to-noise ratio index and the waveform definition index are respectively multiplied by corresponding preset weight coefficients and then weighted and summed, and then the actual measurement reliability index is obtained through the transformation of a negative exponential function based on a natural constant, wherein the exponential function comprises a preset positive gain coefficient.
  5. 5. The method of surface surveying of a building fracture according to claim 1, wherein the probe signal stability is substituted into a max-min normalization formula for processing and generating a probe signal stability index; In the probe frequency adjustment model of step S4: And respectively multiplying the current probe frequency index, the complement of the probe signal stability index and the complement of the expected accuracy index by corresponding preset weight coefficients, summing, limiting the result to be in a range of 0 to 1, and finally mapping to a preset probe frequency adjusting range to obtain the target probe frequency.
  6. 6. The method for surveying the surface of the building cracks according to claim 1, wherein the method further comprises the following steps of S5, constructing a crack state evaluation model according to the average width of the cracks, the included angle between the main trend of the cracks and the acoustic path and the dust concentration in the cracks detected by a crack microscope, and outputting a crack state index; and S6, constructing a measuring point spacing adjustment model according to the actually measured credibility index, the preset measuring point spacing and the crack state index, and outputting the target measuring point spacing.
  7. 7. The method of surface survey of a building fracture according to claim 6, wherein in the fracture state evaluation model of step S5: substituting the average width of the crack, the included angle between the main trend of the crack and the acoustic path and the dust concentration in the crack into a maximum-minimum value normalization formula in sequence for processing, and generating an average width index of the crack, an included angle index and a dust concentration index in sequence; and multiplying the average width index, the included angle index and the dust concentration index of the crack by corresponding preset influence coefficients respectively, and then performing continuous multiplication, and performing power operation of the integral nonlinear adjustment factors to obtain the crack state index.
  8. 8. The method of surface surveying of a building crack according to claim 7, wherein in the measurement point spacing adjustment model of step S6: substituting the preset measuring point spacing into a maximum-minimum value normalization formula for processing, and generating a preset measuring point spacing index; And multiplying the complements of the preset measuring point spacing index, the actually measured credibility index and the crack state index by corresponding preset weight coefficients respectively, summing, limiting the result to be in a range of 0 to 1, and finally mapping the result to a preset measuring point spacing allowable range to obtain the target measuring point spacing.
  9. 9. A surface survey apparatus for a crack in a building, comprising: a memory for storing executable instructions; A processor for carrying out the method of surface investigation of a fracture of a building according to any of the preceding claims 1-8 when executing executable instructions stored in said memory.

Description

Surface survey method and device for building cracks Technical Field The invention belongs to the technical field of nondestructive testing of building structures, and particularly relates to a surface surveying method and device for a building crack. Background The current ultrasonic technology is used as a main stream means for detecting concrete cracks, relies on the diffraction effect of ultrasonic waves at the tip of the cracks, and estimates the crack depth through acoustic time variation. However, in practical engineering applications, this technology faces multiple complex challenges. The physical property differences of the measured material such as water-cement ratio, water content, minimum steel bar clearance and the like obviously change the ultrasonic propagation speed and attenuation characteristics, and the traditional method adopts fixed experience parameters or a single material model, so that the traditional method cannot dynamically adapt to different material states, and the setting deviation of basic acoustic parameters is caused, so that systematic errors are introduced. The frequency selection of the ultrasonic probe depends on the experience or fixed setting of operators, a mechanism for dynamic optimization according to the material characteristics and the crack state is lacking, signals are easy to be excessively scattered at coarse aggregate or cracks due to the fact that the signals are seriously attenuated when the frequency is too high, the resolution is insufficient when the frequency is too low, and the characteristics of fine cracks are difficult to identify. In field detection, the coupling uniformity of the probe and the concrete surface, the actual measurement quality factors such as environmental noise interference and the like directly influence the reliability of original data, and the existing method only tries to filter noise in later data processing or gives out principle requirements in regulations, and fails to quantitatively evaluate the actual measurement quality and feed the actual measurement quality back to detection process control in real time. In conclusion, the existing ultrasonic surface survey method has obvious defects in the aspects of material adaptability, intelligent parameter adjustment and the like, so that the stability and accuracy of a detection result highly depend on subjective experience of operators, and standardized and intelligent high-quality detection is difficult to realize. In view of the above, there is a need in the art for improvements. Disclosure of Invention The embodiment of the invention aims to provide a surface survey method of a building crack, which aims to solve the problems. The invention is realized in that a surface survey method of a crack of a building body comprises the following steps: s1, constructing a measured material physical property evaluation model according to the water-cement ratio, the water content and the minimum steel bar clearance of the measured material, and outputting a material physical property index; S2, constructing an expected accuracy evaluation model according to the physical property index of the material and the probe frequency of the current ultrasonic probe, and outputting an expected accuracy index; s3, constructing an actual measurement quality evaluation model according to the coupling uniformity, the actual measurement signal-to-noise ratio and the waveform definition between the current ultrasonic probe and the concrete surface, and outputting an actual measurement credibility index; and S4, constructing a probe frequency adjustment model according to the current probe frequency, the stability of the probe signal and the expected accuracy index, and outputting the target probe frequency. In a further technical scheme, in the measured material physical property evaluation model in step S1: Substituting the water-cement ratio, the water content and the minimum steel bar clearance of the measured materials into a maximum-minimum value normalization formula in sequence for processing, and generating a water-cement ratio index, a water content index and a minimum steel bar spacing index in sequence; And multiplying the water-cement ratio index, the complement number of the water content index (the value obtained by subtracting the corresponding index from 1) and the complement number of the minimum steel bar spacing index by corresponding preset weight coefficients respectively, then carrying out weighted summation, and then carrying out power operation of a nonlinear adjusting factor to obtain the material physical property index. In a further technical solution, in the expected accuracy evaluation model of step S2: Substituting the probe frequency of the current ultrasonic probe into a maximum-minimum value normalization formula for processing, and generating a probe frequency index; multiplying the material physical property index by a linear combination to obtain an expected accurac