Pile body integrity detection method based on detection data

Abstract

The invention provides a pile body integrity detection method based on detection data, and belongs to the field of pile body structure defect detection.The method comprises the steps that a stress wave # imgabs1 # under the set stress # imgabs0 # condition is applied to the top of a pile body, and an ultrasonic receiver for monitoring the stress wave is arranged at the top of the pile body; calculating the position from the pile body defect to the top of the pile body through reflected ultrasonic waves collected by an ultrasonic receiver, and positioning a pile body defect area; and according to positioning of the pile body defect area, an ultrasonic instrument and an ultrasonic receiver are adopted to conduct ultrasonic detection on pile body defects in the pile body defect area, and the radial width of the pile body defects and the axial width of the pile body defects are calculated through the constructed wave equation. The pile body integrity detection method has the advantages of being wide in detection range, high in resolution ratio, free of damage to the pile body and the like, and powerful guarantee and data support are provided for safety and stability evaluation of pile foundation engineering.

Description

Technical Field

[0001] The present invention relates to the field of pile body defect detection, and in particular to a pile body integrity detection method based on detection data. Background Art

[0002] In pile foundation projects, the integrity of the pile body is directly related to the safety and stability of the entire project. Pile body defects generally include concrete segregation, mud inclusion, necking, poor density, and broken piles. Traditional pile body detection methods include low-strain method, acoustic wave transmission method, high-strain method, and core drilling method. However, there are some obvious defects. The disadvantage of the acoustic wave transmission method is that the pile to be tested needs to be pre-buried with an acoustic detection tube, which increases the cost of the pile foundation. At the same time, the acoustic wave transmission method has a high detection cost. The core drilling method is not necessarily very accurate in judging local defects and horizontal cracks in the pile foundation. It is generally combined with other detection methods. The detection cost is related to the pile length and is also very high. At the same time, in actual use, only one method is generally used, resulting in problems such as limited detection range, low resolution, and possible damage to the pile body. Therefore, the present invention proposes a pile body integrity detection method based on detection data. Summary of the Invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention provides a pile body integrity detection method based on detection data, which locates pile body defects and evaluates defect sizes based on a combination of stress wave detection and ultrasonic detection.

[0004] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is: A method for detecting pile integrity based on detection data is provided, which comprises: Step S1: Apply set stress to the top of the pile Conditional stress wave , and set an ultrasonic receiver to monitor stress waves on the top of the pile body. The reflected ultrasonic waves collected by the ultrasonic receiver are used to calculate the distance between the pile body defect and the top of the pile body, and locate the defective area of ​​the pile body; Step S2: Based on the location of the pile body defect area, ultrasonic testing is performed on the pile body defects within the pile body defect area using an ultrasonic instrument and an ultrasonic receiver. The radial width of the pile body defect and the axial width of the pile body defect are calculated using the constructed wave equation.

[0005] Furthermore, step S1 includes: Step S11: Apply set stress to the top of the pile Conditional stress wave , and set an ultrasonic receiver on the top of the pile to monitor the stress wave, and , is the minimum stress wave that can be sensed by the ultrasonic receiver. is the attenuation coefficient of the stress wave in the length direction of the pile body, is the expansion coefficient, L is the length of the pile; Step S12: establishing a damped wave equation of the stress wave based on the damping effect of the stress wave propagating in the longitudinal direction of the pile body; Step S13: From stress wave At the beginning of the application, the ultrasonic receiver receives the reflected stress wave, obtains the amplitude of the reflected stress wave, and records the reception time of the reflected stress wave. It is used as the propagation time of the stress wave on the pile body and input into the damped wave equation to calculate the position coordinates. x , that is, the distance between the pile defect reflecting the stress wave and the top of the pile body; Step S14: Repeat steps S11-S13 and apply n Secondary stress wave Afterwards, get n Position coordinate data ,calculate n The average value of the position coordinate data , To apply the i Secondary stress wave The obtained position coordinates, i Stress wave The number of times applied; Step S15: Filter out n Position coordinate data The minimum value in and maximum value , calculate the average value With minimum value ,average value With the maximum value The difference between 、 , and filter the difference 、 The maximum value between ; Step S16: Obtain the pile body defect area on the pile body, and the position coordinate range of the pile body defect area is , the middle position of the pile defect area is located at the position coordinate Place.

[0006] Furthermore, the damped wave equation of the stress wave is: ; in, is the function of the stress wave amplitude changing with propagation distance and time, xis the position coordinate along the length of the pile body starting from the top of the pile body, t is the propagation time of the stress wave, A 0 is stress wave The amplitude of is the damping coefficient, is the angular frequency of the stress wave, k is the wave number, is the phase difference, e is a natural constant.

[0007] Furthermore, step S2 includes: Step S21: Move the ultrasonic instrument to the position coordinates of the pile body At the position coordinate where the ultrasonic receiver moves to the opposite side of the ultrasonic instrument At the point where the ultrasonic instrument generates ultrasonic waves, the ultrasonic waves are transmitted through the defective area of ​​the pile body to the ultrasonic receiver; Step S22: Based on the initial sound pressure of the ultrasonic wave emitted by the ultrasonic instrument , calculate the ultrasonic sound pressure received by the ultrasonic receiver under ideal conditions ; Step S23: Setting the sound pressure fluctuation threshold of the ultrasonic wave propagating within the cross section of the pile body ; ; in, is the fluctuation coefficient caused by the unevenness of the pile body material on the ultrasonic wave propagation, is the error coefficient of the ultrasonic receiver; Step S24: Establish the sound pressure fluctuation range of the ultrasonic signal propagating within the cross-section of the pile body ; According to the ultrasonic signal received by the ultrasonic receiver, the sound pressure of the ultrasonic signal and sound pressure fluctuation range Make comparisons; like , then determine the time t The ultrasound signal is normal; like , then determine the time t The ultrasonic signal is abnormal, delete the judgment moment t Ultrasonic signal; like , then determine the time t The ultrasonic signal is an attenuated ultrasonic signal, executing step S25; Step S25: constructing a wave equation for the propagation of ultrasonic waves in the defective area of ​​the pile body. The ultrasonic waves propagate in the defective area of ​​the pile body as cylindrical waves. Step S26: Obtain the time corresponding to each attenuated ultrasonic signal t, input into the wave equation, calculate the radial propagation distance data corresponding to each attenuated ultrasonic signal , w is the number of radial propagation distances, For the w Radial propagation distance; Step S27: Based on the radial propagation distance data Calculate the width of the pile defect reflected by each attenuated ultrasonic signal , get the pile body defect width data ; Step S28: Filter out pile body defect width data The maximum value in and minimum value , the radial width of the pile defect in the pile defect area can be obtained , the axial width of the pile defect is .

[0008] Furthermore, the ultrasonic sound pressure The calculation method is: ; in, d is the diameter of the pile body, are the attenuation constants of solid dielectric materials. f is the frequency of the ultrasound, F is the anisotropy coefficient of the solid dielectric material, D is the grain diameter of the pile material. For concrete piles, the grain diameter is the average diameter of the aggregate.

[0009] Furthermore, the wave equation is: ; in, r is the polar coordinate distance of ultrasonic wave propagating radially along the pile body, c is the ultrasonic wave velocity, is the function of ultrasonic wave changing with space and time, is the polar coordinate angle.

[0010] The present invention provides the following beneficial effects: It proposes a method for locating and sizing pile defects by integrating two detection technologies, avoiding damage to the pile structure itself. It is simple to operate and has low testing costs. Based on the processing and calculation of stress wave and ultrasonic waveform data, it achieves comprehensive, accurate, and nondestructive testing of pile integrity. The proposed pile integrity testing method has the advantages of a wide detection range, high resolution, and no damage to the pile body, providing strong assurance and data support for the safety and stability assessment of pile foundation projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 Flowchart of the pile integrity detection method based on detection data. DETAILED DESCRIPTION

[0012] The specific embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0013] like Figure 1 As shown, a pile body integrity detection method based on detection data includes: Step S1: Apply set stress to the top of the pile Conditional stress wave , and set an ultrasonic receiver for monitoring stress waves at the top of the pile body, calculate the position of the pile body defect from the top of the pile body through the reflected ultrasonic waves collected by the ultrasonic receiver, and locate the pile body defect area. Step S1 specifically includes: Step S11: Apply set stress to the top of the pile Conditional stress wave , and set an ultrasonic receiver on the top of the pile to monitor the stress wave, and , is the minimum stress wave that can be sensed by the ultrasonic receiver. is the attenuation coefficient of the stress wave in the length direction of the pile body, is the expansion coefficient, which indicates the ratio of the stress wave to be amplified. L is the length of the pile; In this embodiment, the stress wave The unit of amplitude is taken as the stress wave. As the stress wave propagates along the length of the pile, its intensity will gradually weaken, and the amplitude of the stress wave will also weaken as the propagation distance increases. Therefore, in order to ensure that the ultrasonic receiver can sense the clear reflected stress wave, it is necessary to ensure that the initial stress wave It has sufficient strength, that is, the amplitude must be large enough.

[0014] Step S12: establishing a damped wave equation of the stress wave based on the damping effect of the stress wave propagating in the longitudinal direction of the pile body; ; in, is the function of the stress wave amplitude changing with propagation distance and time, x is the position coordinate along the length of the pile body starting from the top of the pile body, tis the propagation time of the stress wave, A 0 is stress wave The amplitude of is the damping coefficient, is the angular frequency of the stress wave, k is the wave number, is the phase difference, e is a natural constant; As the stress wave propagates along the length of the pile, it will be reflected by defects on the pile. The reflected stress wave will arrive at the ultrasonic receiver in advance. Therefore, the distance from the pile defect to the top can be calculated based on the transmission time of the reflected stress wave. In this embodiment, the damped wave equation ignores the slope of the stress wave propagating along the length of the pile, simplifying the calculation complexity.

[0015] Step S13: From stress wave At the beginning of the application, the ultrasonic receiver receives the reflected stress wave, obtains the amplitude of the reflected stress wave, and records the reception time of the reflected stress wave. It is used as the propagation time of the stress wave on the pile body and input into the damped wave equation to calculate the position coordinates. x , that is, the distance between the pile defect reflecting the stress wave and the top of the pile body; Step S14: Repeat steps S11-S13 and apply n Secondary stress wave Afterwards, get n Position coordinate data ,calculate n The average value of the position coordinate data , To apply the i Secondary stress wave The obtained position coordinates, i Stress wave The number of times applied; The reflected stress waves are all reflected back by the ultrasonic receiver from the upper half of the pile body defect, while the stress waves cannot reach the lower half of the pile body defect. Therefore, the present invention assumes that the pile body defect is symmetrical in shape, thereby locating the pile body defect. The center of the upper half is first calculated, and then the range of the lower half is fitted through the symmetry effect.

[0016] Step S15: Filter out n Position coordinate data The minimum value in and maximum value , calculate the average value With minimum value ,average value With the maximum value The difference between 、 , and filter the difference 、 The maximum value between ; Step S16: Obtain the pile body defect area on the pile body, and the position coordinate range of the pile body defect area is , the middle position of the pile defect area is located at the position coordinate Place.

[0017] Step S2: Based on the location of the pile body defect area, ultrasonic testing is performed on the pile body defects within the pile body defect area using an ultrasonic instrument and an ultrasonic receiver. The radial width of the pile body defect and the axial width of the pile body defect are calculated using the constructed wave equation. Step S2 specifically includes: Step S21: Move the ultrasonic instrument to the position coordinates of the pile body At the position coordinate where the ultrasonic receiver moves to the opposite side of the ultrasonic instrument At the point where the ultrasonic instrument generates ultrasonic waves and transmits them through the defective area of ​​the pile body to the ultrasonic receiver, the ultrasonic receiver and the ultrasonic instrument are symmetrical along the axis of the pile body; Step S22: Based on the initial sound pressure of the ultrasonic wave emitted by the ultrasonic instrument , calculate the ultrasonic sound pressure received by the ultrasonic receiver under ideal conditions ; ; in, d is the diameter of the pile body, are the attenuation constants of solid dielectric materials. f is the frequency of the ultrasound, F is the anisotropy coefficient of the solid dielectric material, D is the grain diameter of the pile material. For concrete piles, the grain diameter is the average diameter of the aggregate; Step S23: Setting the sound pressure fluctuation threshold of the ultrasonic wave propagating within the cross section of the pile body ; ; in, is the fluctuation coefficient caused by the unevenness of the pile body material on the ultrasonic wave propagation, is the error coefficient of the ultrasonic receiver, which is generally taken as ; Step S24: Establish the sound pressure fluctuation range of the ultrasonic signal propagating within the cross-section of the pile body ; According to the ultrasonic signal received by the ultrasonic receiver, the sound pressure of the ultrasonic signal and sound pressure fluctuation range Make comparisons; like , then determine the timet The ultrasound signal is normal; like , then determine the time t The ultrasonic signal is abnormal, delete the judgment moment t Ultrasonic signal; like , then determine the time t The ultrasonic signal is an attenuated ultrasonic signal, executing step S25; During the transmission process of the ultrasonic signal inside the pile body, it will be greatly weakened by the pile body defects and the transmission speed of the ultrasonic signal will be changed. The width of the pile body defect can be calculated by the difference in the speed of the ultrasonic signal propagating between the pile body material medium and the defective medium.

[0018] Step S25: constructing a wave equation for the propagation of ultrasonic waves in the defective area of ​​the pile body. The ultrasonic waves propagate in the defective area of ​​the pile body as cylindrical waves. ; in, r is the polar coordinate distance of ultrasonic wave propagating radially along the pile body, c is the ultrasonic wave velocity, is the function of ultrasonic wave changing with space and time, is the polar coordinate angle; Step S26: Obtain the time corresponding to each attenuated ultrasonic signal t , input into the wave equation, calculate the radial propagation distance data corresponding to each attenuated ultrasonic signal , w is the number of radial propagation distances, For the w Radial propagation distance; Step S27: Based on the radial propagation distance data Calculate the width of the pile defect reflected by each attenuated ultrasonic signal , get the pile body defect width data ; Step S28: Filter out pile body defect width data The maximum value in and minimum value , the radial width of the pile defect in the pile defect area can be obtained , the axial width of the pile defect is .

[0019] This invention proposes a method for locating and sizing pile defects by combining two detection technologies, avoiding damage to the pile structure itself. Simultaneously, it offers simple operation and low testing costs. Based on the processing and calculation of stress wave and ultrasonic waveform data, it enables comprehensive, accurate, and nondestructive testing of pile integrity. The proposed pile integrity testing method boasts a wide detection range, high resolution, and no damage to the pile body, providing strong assurance and data support for safety and stability assessments of pile foundation projects.

Claims

1. A pile body integrity detection method based on detection data, characterized in that: include: Step S1: Apply set stress to the top of the pile Stress wave conditions , and an ultrasonic receiver for monitoring stress waves is set at the top of the pile body, and the position of the pile body defect from the top of the pile body is calculated through the reflected ultrasonic waves collected by the ultrasonic receiver, and the defective area of ​​the pile body is located; Step S2: Based on the location of the pile body defect area, ultrasonic detection is performed on the pile body defects in the pile body defect area using an ultrasonic instrument and an ultrasonic receiver, and the radial width of the pile body defect and the axial width of the pile body defect are calculated using the constructed wave equation.

2. The pile body integrity detection method based on detection data according to claim 1 is characterized in that: The step S1 comprises: Step S11: Apply set stress to the top of the pile Stress wave conditions , and an ultrasonic receiver is set on the top of the pile to monitor the stress wave, and , is the minimum stress wave that can be sensed by the ultrasonic receiver. is the attenuation coefficient of stress wave in the length direction of the pile body, is the expansion coefficient, L is the length of the pile; Step S12: establishing a damped wave equation of the stress wave according to the damping effect of the stress wave propagating in the length direction of the pile body; Step S13: From the stress wave At the beginning of the application, the ultrasonic receiver receives the reflected stress wave, obtains the amplitude of the reflected stress wave, and records the reception time of the reflected stress wave. It is used as the propagation time of the stress wave on the pile body and input into the damped wave equation to calculate the position coordinates. x , that is, the distance between the pile body defect reflecting the stress wave and the top of the pile body; Step S14: Repeat steps S11-S13 and apply n Secondary stress wave Afterwards, we get n Position coordinate data ,calculate n The average value of the position coordinate data , To apply the i Secondary stress wave The obtained position coordinates, i Stress wave The number of times applied; Step S15: Filter out n Position coordinate data The minimum value in and maximum value , calculate the average With minimum ,average value With the maximum value The difference between , , and filter the difference , The maximum value between ; Step S16: Obtain the pile body defect area on the pile body, and the position coordinate range of the pile body defect area is , the middle position of the pile defect area is located at the position coordinate Place.

3. The pile body integrity detection method based on detection data according to claim 2 is characterized in that: The damped wave equation of the stress wave is: ； in, is the function of the amplitude of the stress wave changing with the propagation distance and time, x is the position coordinate along the length of the pile body starting from the top of the pile body, t is the propagation time of the stress wave, A 0 is stress wave The amplitude of is the damping coefficient, is the angular frequency of the stress wave, k is the wave number, is the phase difference, e is a natural constant.

4. The pile body integrity detection method based on detection data according to claim 1 is characterized in that: The step S2 comprises: Step S21: Move the ultrasonic instrument to the position coordinates of the pile body At the ultrasonic receiver, the position coordinates to the opposite side of the ultrasonic instrument are At the point, the ultrasonic instrument generates ultrasonic waves and transmits them through the defective area of ​​the pile body to the ultrasonic receiver; Step S22: Based on the initial sound pressure of the ultrasonic wave emitted by the ultrasonic instrument , calculate the ultrasonic sound pressure received by the ultrasonic receiver under ideal conditions ; Step S23: Setting the sound pressure fluctuation threshold of the ultrasonic wave propagating within the cross-section of the pile body ; ； in, is the fluctuation coefficient caused by the unevenness of the pile material on ultrasonic propagation, is the error coefficient of the ultrasonic receiver; Step S24: Establish the sound pressure fluctuation range of the ultrasonic signal propagating within the cross-sectional range of the pile body ; According to the ultrasonic signal received by the ultrasonic receiver, the sound pressure of the ultrasonic signal The range of sound pressure fluctuation Make comparisons; like , then determine the time t The ultrasound signal is normal; like , then determine the time t The ultrasonic signal is abnormal, delete the judgment time t Ultrasonic signal; like , then determine the time t The ultrasonic signal is an attenuated ultrasonic signal, executing step S25; Step S25: constructing a wave equation for the propagation of ultrasonic waves in the defective region of the pile body, where the ultrasonic waves propagate as cylindrical waves in the defective region of the pile body; Step S26: Obtain the time corresponding to each attenuated ultrasonic signal t , input into the wave equation, calculate the radial propagation distance data corresponding to each attenuated ultrasonic signal , w is the number of radial propagation distances, For the w Radial propagation distance; Step S27: Based on the radial propagation distance data Calculate the width of the pile defect reflected by each attenuated ultrasonic signal , get the pile body defect width data ; Step S28: Filter out pile body defect width data The maximum value in and minimum value , the radial width of the pile defect in the pile defect area can be obtained , the axial width of the pile defect is .

5. The pile body integrity detection method based on detection data according to claim 4 is characterized in that: The ultrasonic sound pressure The calculation method is: ； in, d is the diameter of the pile, are the attenuation constants of solid dielectric materials. f is the frequency of the ultrasonic wave, F is the anisotropy coefficient of the solid dielectric material, D is the grain diameter of the pile material. For concrete piles, the grain diameter is the average diameter of the aggregate.

6. The pile body integrity detection method based on detection data according to claim 4 is characterized in that: The wave equation is: ； in, r is the polar coordinate distance of ultrasonic wave propagating radially in the pile body, c is the speed of ultrasonic wave, is the function of ultrasonic wave changing with space and time, is the polar coordinate angle.

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