Ultrasonic-rebound comprehensive detection method and system for concrete strength of bridge pier column

Abstract

The application provides an ultrasonic-rebound comprehensive detection method and system for the strength of bridge pier concrete, relates to the technical field of structure nondestructive testing, and comprises the following steps: obtaining ultrasonic propagation velocity data of a bridge pier part to be detected; obtaining rebound value data of the bridge pier part to be detected; coupling the ultrasonic propagation velocity data and the rebound value data, and determining the strength of the concrete of the part to be detected in combination with the pouring stratification direction of the bridge pier concrete, and the strength growth coefficient corresponding to the curing age. The accuracy and stability of the detection of the strength of the bridge pier concrete are significantly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of structural nondestructive testing, in particular to an ultrasonic-rebound comprehensive detection method and system for concrete strength of a bridge pier column. BACKGROUND

[0002] As a key load-bearing component of a bridge structure, the concrete strength of a bridge pier column is directly related to the overall safety and durability of the bridge. With the increase of service time and the influence of factors such as vehicle load and environmental erosion, the concrete of the pier column may have problems such as strength attenuation and internal defects, so it is necessary to accurately detect its strength on a regular basis.

[0003] Currently, concrete strength detection methods are mainly divided into destructive detection and nondestructive detection. Although destructive detection (such as the core drilling method) has high accuracy, it can cause damage to the pier column structure and has a limited sampling range, making it difficult to fully reflect the overall strength condition. Nondestructive detection is widely used in engineering due to its non-destructive nature and ability to detect large areas. Among them, ultrasonic detection and rebound detection are two commonly used non-destructive detection methods. However, the bridge pier column has a cylindrical curved surface structure, the concrete pouring layer is clear, and the curing conditions are complex. Single ultrasonic detection or rebound detection is easily affected by structural morphology, material properties, and environmental factors, resulting in large deviations in the detection results. Therefore, the comprehensive detection method combining ultrasonic detection and rebound detection has become a research focus, but existing comprehensive methods still have deficiencies in data coupling processing and structural property adaptation, making it difficult to meet the demand for accurate detection of the concrete strength of the bridge pier column.

[0004] Therefore, the present application provides an ultrasonic-rebound comprehensive detection method and system for concrete strength of a bridge pier column. SUMMARY

[0005] The present application provides an ultrasonic-rebound comprehensive detection method and system for concrete strength of a bridge pier column, which accurately matches the spatial positions of ultrasonic detection points and rebound measurement areas, combines layer-by-layer correction and regional calibration, considers the influence of pouring layer direction and dynamic age coefficient, and enhances data correlation. Through fine coupling processing, the interference of structure and material factors is reduced, significantly improving the accuracy and stability of the detection of the concrete strength of the bridge pier column.

[0006] The present application provides an ultrasonic-rebound comprehensive detection method for concrete strength of a bridge pier column, comprising:

[0007] Step 1: Obtain ultrasonic propagation velocity data of the bridge pier column to be detected;

[0008] Step 2: Obtain rebound value data of the bridge pier column to be detected;

[0009] Step 3: coupling the ultrasonic propagation velocity data and the rebound value data, combining the pouring stratification direction of the bridge pier column concrete, the strength growth coefficient corresponding to the curing age to determine the concrete strength of the to-be-detected part.

[0010] Preferably, the ultrasonic propagation velocity data of the to-be-detected part of the bridge pier column is obtained, including:

[0011] A preset number of ultrasonic transducer arrays are arranged in a ring shape at different heights of the to-be-detected part of the bridge pier column, and each ultrasonic transducer array includes a transmitting transducer and a receiving transducer.

[0012] In the ring-shaped area covered by each ultrasonic transducer array, a preset number of detection points are divided at equal angle intervals, and each detection point corresponds to a set of transmitting transducer and receiving transducer.

[0013] A pulse excitation signal is applied to the transmitting transducer, and the frequency of the pulse excitation signal is determined according to the maximum particle size of the coarse aggregate of the bridge pier column concrete.

[0014] Based on the ultrasonic signal received by the receiving transducer after penetrating the concrete, the propagation time of the ultrasonic pulse from the transmitting transducer to the receiving transducer is recorded, and then the ultrasonic propagation time of each detection point is obtained.

[0015] According to the straight-line distance between the transmitting transducer and the receiving transducer and the measured ultrasonic propagation time, the ultrasonic propagation velocity data is calculated.

[0016] Preferably, the rebound value data of the to-be-detected part of the bridge pier column is obtained, including:

[0017] In the ring-shaped area corresponding to the height of the ultrasonic transducer array at the to-be-detected part of the bridge pier column, a number of rebound measurement areas equal to the number of detection points are divided, and each rebound measurement area is spatially deviated from the corresponding ultrasonic detection point by not more than a preset deviation value.

[0018] A preset rebounder performs a preset number of continuous rebounds on each rebound measurement area, and the angle between the axis of the preset rebounder and the normal direction of the surface of the bridge pier column is not more than a preset angle during the continuous rebounding process. The rebound value after each rebound in the continuous rebounding process is recorded.

[0019] The abnormal values caused by the deviation of the rebound position are removed from the rebound values, and the average value of the remaining valid rebound values is taken as the rebound value data of the corresponding rebound measurement area.

[0020] Preferably, the ultrasonic propagation velocity data and the rebound value data are coupled and processed, including:

[0021] The longitudinal detection layers are divided according to the layering direction of the concrete pouring of the bridge pier column, each layer corresponds to an independent speed correction coefficient, and the ultrasonic propagation speed data is corrected layer by layer based on the speed correction coefficient;

[0022] The rebound test area is divided into preset grade areas according to the surface carbonization depth, and the rebound value data is regionally calibrated;

[0023] An ultrasonic-rebound data correlation matrix is established based on the corrected ultrasonic propagation speed data and the calibrated rebound value data, wherein the row dimension of the matrix corresponds to the spatial coordinates of the ultrasonic detection points, and the column dimension corresponds to the spatial coordinates of the rebound test area;

[0024] The coordinate deviation values of the spatial coordinates of the ultrasonic detection points and the spatial coordinates of the rebound test area are calculated, and the correlation weight is determined based on the coordinate deviation values;

[0025] The corrected ultrasonic propagation speed data and the calibrated rebound value data are combined and fused to obtain coupled data based on the correlation weight.

[0026] Preferably, the longitudinal detection layers are divided according to the layering direction of the concrete pouring of the bridge pier column, each layer corresponds to an independent speed correction coefficient, and the ultrasonic propagation speed data is corrected layer by layer based on the speed correction coefficient, including:

[0027] The layered records in the concrete pouring process of the bridge pier column are obtained, and the deviation rate of the actual thickness and the design thickness of each longitudinal detection layer is determined;

[0028] The dispersion of the ultrasonic propagation speed data in each longitudinal detection layer is analyzed, the ratio of the standard deviation to the average value is calculated, when the ratio exceeds a preset percentage, the layer data is reselected, and the abnormal speed value deviating from and exceeding the average value by a preset multiple standard deviation is removed to recalculate the correction coefficient.

[0029] The ultrasonic propagation speed data is corrected layer by layer based on the correction coefficient.

[0030] Preferably, the deviation rate of the actual thickness and the design thickness of each longitudinal detection layer is determined, including:

[0031] When the deviation rate is within a preset deviation rate, the basic correction coefficient is used;

[0032] Or, when the deviation rate exceeds the preset deviation rate, the correction coefficient is additionally adjusted by a preset proportion for each increase of the preset deviation rate based on the basic correction coefficient.

[0033] Preferably, the concrete strength of the to-be-detected part is determined in combination with the layering direction of the concrete pouring of the bridge pier column and the strength growth coefficient corresponding to the curing age, including:

[0034] For the coupled data, a transverse analysis unit is divided according to the direction of the pouring layer, wherein each transverse analysis unit corresponds to a ring sector area of a longitudinal detection layer;

[0035] The direction of the coupled data in each transverse analysis unit is analyzed;

[0036] The coupled data in each transverse analysis unit is corrected based on the direction;

[0037] The actual curing record of the concrete of the bridge pier column is obtained, and the difference between the curing age at the time of detection and the standard curing age is determined;

[0038] The corresponding curve is called from the preset database based on the difference, and the corresponding strength growth coefficient is determined based on the curve;

[0039] The coupled data of each transverse analysis unit after the layering correction is multiplied by the corresponding strength growth coefficient to obtain the initial strength value of the unit, and the initial strength values of all transverse analysis units in the same longitudinal detection layer are weighted and averaged;

[0040] The average strength value of the longitudinal detection layer is subjected to spatial continuity verification, and the deviation rate of the average strength values of adjacent layers is calculated;

[0041] The coupled data in each transverse analysis unit is re-corrected based on the deviation rate, and when the deviation rate is reduced to within a preset range, the re-correction is stopped, and the concrete strength of the detection part is obtained.

[0042] Preferably, the corresponding curve is called from the preset database based on the difference, and the corresponding strength growth coefficient is determined based on the curve, comprising:

[0043] When the difference is negative, the early growth curve corresponding to the cementitious material variety is called from the preset database, and the coefficient value corresponding to the actual age is intercepted;

[0044] When the difference is positive, the late growth curve is called from the preset database;

[0045] The coefficient value corresponding to the actual age is determined as the corresponding strength growth coefficient based on the early growth curve and the late growth curve.

[0046] The present application provides an ultrasonic rebound comprehensive detection system for the concrete strength of a bridge pier column, comprising:

[0047] An ultrasonic data acquisition module: acquiring ultrasonic propagation speed data of the detection part of the bridge pier column;

[0048] A rebound data acquisition module: acquiring rebound value data of the detection part of the bridge pier column;

[0049] Data processing module: coupling processing of ultrasonic propagation velocity data and rebound value data, combined with the pouring stratification direction of the bridge pier column concrete, the strength growth coefficient corresponding to the curing age to determine the concrete strength of the detected part.

[0050] Compared with the prior art, the beneficial effects of the present application are as follows:

[0051] By precisely matching the spatial positions of the ultrasonic detection points and the rebound measurement area, combined with layered correction, regional calibration, considering the influence of pouring stratification direction and dynamic age coefficient, the data correlation is enhanced; after fine coupling processing, the interference of structure and material factors is reduced, and the accuracy and stability of the bridge pier column concrete strength detection are significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the present application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0053] Figure 1 is a flowchart of the ultrasonic rebound comprehensive detection method for bridge pier column concrete strength provided by the embodiments of the present application.

[0054] Figure 2 is a structural schematic diagram of the ultrasonic rebound comprehensive detection system for bridge pier column concrete strength provided by the embodiments of the present application. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical scheme and advantages of the present application more clear, the technical scheme in the present application will be described clearly and completely in the following combined with the drawings in the present application. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0056] Embodiment 1:

[0057] The embodiments of the present application provide an ultrasonic rebound comprehensive detection method for bridge pier column concrete strength, as shown in Figure 1 , comprising:

[0058] Step 1: obtaining ultrasonic propagation velocity data of the detected part of the bridge pier column;

[0059] Step 2: obtaining rebound value data of the detected part of the bridge pier column;

[0060] Step 3: coupling the ultrasonic propagation velocity data and the rebound value data, combining the pouring bedding direction of the bridge pier column concrete and the strength growth coefficient corresponding to the curing age to determine the concrete strength of the to-be-detected part.

[0061] In this embodiment, the pouring bedding direction refers to the extension direction of the layered structure parallel to the pouring surface formed by the hardening of the concrete during the layered pouring process of the bridge pier column concrete, which is specifically the trend of the longitudinal bedding interface formed by the layered stacking along the height direction of the pier column, and has significant correlation with the aggregate distribution, bubble arrangement and density change in the concrete.

[0062] In this embodiment, the curing age refers to the natural curing time period experienced by the bridge pier column concrete from the completion of pouring and reaching the initial setting state to the implementation of the present detection method, including the standard curing stage and the subsequent natural environment curing stage, the time length of which directly corresponds to the time axis of the concrete strength growth curve, and is related to the cumulative effect of temperature and humidity in the actual curing process.

[0063] The beneficial effects of the above technical solutions are: by precisely matching the spatial positions of the ultrasonic detection points and the rebound measurement areas, combining layered correction and regional calibration, considering the influence of the pouring bedding direction and the dynamic age coefficient, the data correlation is enhanced; after fine coupling processing, the interference of structure and material factors is reduced, and the accuracy and stability of the bridge pier column concrete strength detection are significantly improved.

[0064] Embodiment 2:

[0065] The embodiment of the present application provides an ultrasonic rebound comprehensive detection method for the strength of bridge pier column concrete, and obtains the ultrasonic propagation velocity data of the to-be-detected part of the bridge pier column, which comprises:

[0066] A preset number of ultrasonic transducer arrays are arranged in different heights of the to-be-detected part of the bridge pier column, and each ultrasonic transducer array comprises a transmitting transducer and a receiving transducer;

[0067] In the circumferential area covered by each ultrasonic transducer array, a preset number of detection points are divided at equal angle intervals, and each detection point corresponds to a set of aligned combination of transmitting transducers and receiving transducers;

[0068] A pulse excitation signal is applied to the transmitting transducer, and the frequency of the pulse excitation signal is determined according to the maximum particle size of the coarse aggregate of the bridge pier column concrete;

[0069] Based on the ultrasonic signal received by the receiving transducer after penetrating the concrete, the propagation time of the ultrasonic pulse from the transmitting transducer to the receiving transducer is recorded, and then the ultrasonic propagation time of each detection point is obtained;

[0070] According to the straight line distance between the transmitting transducer and the receiving transducer and the measured ultrasonic propagation time, the ultrasonic propagation speed data is calculated.

[0071] In this embodiment, the preset number of ultrasonic transducer arrays refers to at least two groups;

[0072] In this embodiment, each group of ultrasonic transducer arrays includes a transmitting transducer and a receiving transducer, and the transmitting transducer and the receiving transducer are distributed radially symmetrically along the pier column, and the distance between every two groups of arrays in the height direction is 1 / 3-1 / 2 of the diameter of the pier column.

[0073] In this embodiment, the excitation frequency is determined according to the maximum particle size of the coarse aggregate of the bridge pier concrete, for example, when the maximum particle size of the coarse aggregate is 20-40mm, the excitation frequency is set to 30-50kHz; when the maximum particle size of the coarse aggregate is 40-60mm, the excitation frequency is set to 20-30kHz.

[0074] In this embodiment, the straight line distance is measured in real time after the transducer is installed by a laser range finder.

[0075] The beneficial effects of the above technical scheme are: through the circumferential layered arrangement of the transducer array, combined with the equiangular division of the detection points, the spatial distribution uniformity of the ultrasonic data is improved; the excitation frequency is dynamically matched according to the particle size of the coarse aggregate, which reduces the signal attenuation interference; the effective value is taken by multiple measurements, which reduces the accidental error and enhances the representativeness and accuracy of the ultrasonic propagation speed data, providing a reliable foundation for subsequent strength detection.

[0076] Embodiment 3:

[0077] The embodiment of the present application provides an ultrasonic rebound comprehensive detection method for the strength of the bridge pier concrete, and obtains the rebound value data of the bridge pier detection part, which comprises:

[0078] In the circumferential region corresponding to the ultrasonic transducer array arrangement height of the bridge pier detection part, the rebound measurement area is divided into the same number of detection points, and the spatial position deviation of each rebound measurement area and the corresponding ultrasonic detection point does not exceed the preset deviation value;

[0079] Based on the preset rebound hammer, the rebound value data of each rebound measurement area is obtained by continuous rebounding for a preset number of times, the angle between the axis of the preset rebound hammer and the normal direction of the surface of the bridge pier is kept not more than a preset angle during the continuous rebounding process, and the rebound value after each rebounding in the continuous rebounding process is recorded.

[0080] The abnormal values caused by the deviation of the rebounding position are eliminated from the rebound values, and the average value of the remaining effective rebound values is taken as the rebound value data of the corresponding rebound measurement area.

[0081] In the embodiment, the preset rebound hammer is an arc-shaped rebound hammer adapted to the curved surface of the bridge pier column, the end of the rebound hammer rod is provided with a rotatable arc-shaped contact head, the curvature of the contact head is matched with the curvature of the pier column surface, and the rebound hammer is fixed on the surface of the measurement area through a magnetic attraction positioning device before rebounding.

[0082] In the embodiment, an abnormal value is determined when a certain value deviates from the remaining values by more than 10%.

[0083] The above technical scheme has the beneficial effects that the problems of spatial mispositioning of the existing rebound measurement area and ultrasonic detection point, large rebound angle deviation, and data interference by abnormal values are solved, the correlation and stability of the rebound data and ultrasonic data are improved through spatial corresponding design, angle control, and abnormal value elimination, and the detection reliability is improved.

[0084] Embodiment 4:

[0085] The ultrasonic-rebound comprehensive detection method for the bridge pier column concrete strength provided in the embodiments of the present application couples the ultrasonic propagation speed data and the rebound value data, and includes the following steps.

[0086] The longitudinal detection layers are divided according to the layering direction of the bridge pier column concrete pouring, each layer corresponds to an independent speed correction coefficient, and the ultrasonic propagation speed data is corrected layer by layer based on the speed correction coefficient.

[0087] The rebound measurement area is divided into preset level regions according to the surface carbonization depth, and the rebound value data is regionally calibrated.

[0088] An ultrasonic-rebound data correlation matrix is established based on the corrected ultrasonic propagation speed data and the calibrated rebound value data, wherein the row dimension of the matrix corresponds to the spatial coordinates of the ultrasonic detection point, and the column dimension corresponds to the spatial coordinates of the rebound measurement area.

[0089] The coordinate deviation values of the spatial coordinates of the ultrasonic detection point and the spatial coordinates of the rebound measurement area are calculated, and the correlation weight is determined based on the coordinate deviation values.

[0090] The corrected ultrasonic propagation speed data and the calibrated rebound value data are combined and fused based on the correlation weight to obtain coupled data.

[0091] In the embodiment, the speed correction coefficient is determined according to the actual thickness deviation rate of the longitudinal detection layer, the design thickness, and other pouring characteristics such as the vibration compaction degree, is a quantitative parameter for correcting the deviation of the ultrasonic propagation speed data caused by the layering difference, and is independently valued for each layer to adapt to the performance difference of each layer of concrete.

[0092] In this embodiment, the preset level area refers to different area levels divided according to the surface carbonization depth of the rebound test area. Each level corresponds to a specific rebound value calibration rule to eliminate the influence of carbonization degree on the rebound value and improve data consistency.

[0093] In this embodiment, the correlation weight refers to a quantitative coefficient determined based on the spatial coordinate deviation value of the ultrasonic detection point and the rebound test area, used to represent the spatial correlation of the two data. The weight size determines the contribution degree of the corresponding ultrasonic and rebound data in the fusion.

[0094] In this embodiment, an ultrasonic-rebound data correlation matrix is established based on the corrected ultrasonic propagation speed data and the calibrated rebound value data. The row dimension of the matrix corresponds to the spatial coordinates of the ultrasonic detection points, and the column dimension corresponds to the spatial coordinates of the rebound test areas. The three-dimensional spatial coordinates of each ultrasonic detection point and the center of the rebound test area are collected by a high-precision positioning device, with a coordinate accuracy of up to millimeter level. The ultrasonic detection point coordinates are based on the midpoint of the transmitting transducer and the receiving transducer, and the rebound test area coordinates are based on the geometric center of the test area. The collected three-dimensional spatial coordinates are imported into a preset spatial coordinate system, which takes the center point of the bottom of the bridge pier column as the origin, the pier column axis as the Z axis, and the horizontal radial as the X axis and Y axis, to complete the coordinate standardization conversion. All coordinate combinations of the ultrasonic detection points and the rebound test areas are traversed, and the spatial Euclidean distance of each pair of combination is calculated. When the Euclidean distance is less than or equal to 5 times the ultrasonic transducer array spacing, it is marked as a potential correlation pair, otherwise it is determined as unrelated. The potential correlation pairs are verified for internal structure consistency of the concrete. By analyzing the waveform attenuation characteristics in the ultrasonic propagation speed data, if the ultrasonic waveform attenuation trend of a certain potential correlation pair is consistent with the surface hardness distribution trend of the rebound test area, it is confirmed as an effective correlation pair. The effective correlation pairs are assigned with initial matrix element values. The initial value is determined according to the Z-axis coordinate difference between the ultrasonic detection point and the rebound test area. When the Z-axis coordinate difference is 0, the initial value is set to 1.0. The initial value decreases by 0.1 for every 10cm increase in coordinate difference, with a minimum of not less than 0.5. The initial matrix element values of the effective correlation pairs are filled into the corresponding row and column positions of the ultrasonic-rebound data correlation matrix. The unrelated positions are filled with null values or specific identifiers to form a preliminary matrix. The preliminary matrix is normalized to make the sum of each row element 1.0, ensuring that the matrix meets the mathematical properties of weight distribution in subsequent fusion calculation.

[0095] In this embodiment, the coupling data is obtained by combining the corrected ultrasonic propagation velocity data and the calibrated rebound value data based on the correlation weight, including: the fusion process adopts a double-loop iteration mechanism, the inner loop is 10-15 times of iteration calculation for the data of a single detection point and the corresponding measurement area, the fusion ratio of ultrasonic data and rebound data is increased or decreased by 3% alternately each time, until the deviation of the results of two iterations is less than 0.2MPa; the outer loop is 3-5 times of global optimization for all detection point data of the entire bridge pier, and the fusion weight of each detection point is adjusted according to the distribution characteristics of the fused data when the dispersion degree of the data in a certain area exceeds 10%, and the weight of the area is increased by 20%-25% to enhance the representativeness of the data.

[0096] The beneficial effects of the above technical solution are: the ultrasonic data is corrected layer by layer according to the pouring layering, which effectively eliminates the interference of layering differences on the detection results; the rebound value is calibrated by grade according to the carbonization depth, which improves the correction accuracy of the influence of the surface state; the spatial correlation matrix and the coordinate deviation weight are used to realize accurate matching of the data, avoid the one-sidedness of traditional simple weighting, make the coupling data more consistent with the actual strength distribution of the bridge pier concrete, and significantly enhance the reliability of the comprehensive detection.

[0097] Embodiment 5:

[0098] The embodiment of the application provides an ultrasonic rebound comprehensive detection method for the strength of bridge pier concrete, divides longitudinal detection layers according to the pouring layering direction of the bridge pier concrete, and each layer corresponds to an independent velocity correction coefficient, and the ultrasonic propagation velocity data is corrected layer by layer based on the velocity correction coefficient, including:

[0099] The layering records in the pouring process of the bridge pier concrete are obtained, and the deviation rate of the actual thickness and the design thickness of each longitudinal detection layer is determined.

[0100] The ultrasonic propagation velocity data in each longitudinal detection layer is analyzed for dispersion, and the ratio of the standard deviation to the average value is calculated, when the ratio exceeds a preset percentage, the layer data is subjected to secondary screening, and the abnormal velocity value deviating from and exceeding the average value by a preset multiple standard deviation is removed, and the correction coefficient is recalculated.

[0101] The ultrasonic propagation velocity data is corrected layer by layer based on the correction coefficient.

[0102] In this embodiment, the deviation rate of the actual thickness and the design thickness of each longitudinal detection layer is that the design thickness in the pouring record of the bridge pier concrete is compared with the thickness of the longitudinal detection layer actually detected, the percentage value of (actual thickness-design thickness) to the design thickness is calculated, and the influence degree of the pouring size deviation of each layer on the ultrasonic propagation velocity is quantified.

[0103] In this embodiment, the dispersion analysis refers to: statistical analysis is carried out on the ultrasonic propagation speed data in the same longitudinal detection layer, the dispersion degree of the data is measured by calculating the ratio of the standard deviation to the average value, and the uniformity of the concrete quality of the layer is judged.

[0104] In this embodiment, the preset percentage refers to: the dispersion threshold value preset according to the design strength grade and construction specification of the bridge pier concrete, usually 5%-10%, when the ratio of the standard deviation to the average value exceeds the value, it indicates that the data exists significant fluctuation.

[0105] In this embodiment, the secondary screening refers to: for the longitudinal detection layer data with large dispersion, the standard deviation of the preset multiple (usually 1.5-2 times) is used as the judgment standard, the abnormal speed value exceeding the range is removed, and the remaining data is recalculated to correct the coefficient, so as to reduce the interference of abnormal value on detection accuracy.

[0106] The beneficial effects of the above technical scheme are: the correction coefficient is determined combined with the thickness deviation rate of the pouring layered record, the influence of the layer thickness difference on the ultrasonic data is eliminated; the abnormal value is removed through dispersion analysis, the data fluctuation interference is reduced, the ultrasonic propagation speed data after layering correction is more consistent with the actual concrete quality of each longitudinal detection layer, the ultrasonic data distortion problem caused by ignoring the layering difference in the prior art is solved, and the data reliability is improved.

[0107] Embodiment 6:

[0108] The embodiment of the present application provides an ultrasonic rebound comprehensive detection method for the strength of bridge pier concrete, determines the deviation rate of the actual thickness and the design thickness of each longitudinal detection layer, comprising:

[0109] When the deviation rate is within the preset deviation rate, the basic correction coefficient is used;

[0110] Or, when the deviation rate exceeds the preset deviation rate, the correction coefficient is additionally adjusted by the preset proportion for each increase of the preset deviation rate based on the basic correction coefficient.

[0111] In this embodiment, the preset deviation rate refers to the thickness fluctuation range allowed based on the bridge pier concrete pouring construction specification, specifically ± 3%, that is, when the difference between the actual thickness and the design thickness of the longitudinal detection layer accounts for a percentage between-3% and 3% of the design thickness, it is determined that the deviation is within the allowed range.

[0112] In this embodiment, the basic correction coefficient refers to the reference correction parameter set for the longitudinal detection layer with the deviation rate within the preset deviation rate, and the value is 1.0. The coefficient is determined based on the ultrasonic propagation characteristic experimental data of the same type of pier concrete under standard pouring conditions, and is used to ensure the reference consistency of the detection layer data without deviating from the design thickness.

[0113] In this embodiment, the preset ratio refers to the additional adjustment range of the correction coefficient when the deviation rate exceeds the preset deviation rate, specifically, for every 1% increase in the deviation rate, the correction coefficient is additionally adjusted by 0.3%-0.5%, and the adjustment range increases in steps with the increase of the deviation rate, and the range of the ratio is obtained through comparison of the correlation experiments of the compressive strength of concrete and the ultrasonic speed under different deviation degrees.

[0114] The beneficial effects of the above technical solution are: by adjusting the correction coefficient in stages according to the preset deviation rate, the limitation of the prior art that uses a unified correction for thickness deviation is solved. When the thickness deviation is within the preset range, the basic coefficient is used, and when it exceeds the limit, it is additionally adjusted in proportion, so that the correction coefficient is dynamically matched with the actual thickness deviation, the ultrasonic speed data deviation caused by the difference in pouring thickness is accurately compensated, the pertinence and accuracy of the layered correction are improved, and more reliable basic data are provided for subsequent strength calculation.

[0115] Embodiment 7:

[0116] The embodiment of the present application provides an ultrasonic rebound comprehensive detection method for the strength of bridge pier concrete, determines the concrete strength of the detection part by combining the pouring stratification direction of the bridge pier concrete and the strength growth coefficient corresponding to the curing age, and comprises the following steps:

[0117] For the coupling data, a horizontal analysis unit is divided according to the pouring stratification direction, wherein each horizontal analysis unit corresponds to a ring-shaped area of a longitudinal detection layer;

[0118] The direction of the coupling data in each horizontal analysis unit is analyzed;

[0119] The coupling data in each horizontal analysis unit is corrected based on the direction;

[0120] The actual curing record of the bridge pier concrete is obtained, and the difference between the curing age at the time of detection and the standard curing age is determined;

[0121] A corresponding curve is retrieved in a preset database based on the difference, and a corresponding strength growth coefficient is determined based on the curve;

[0122] The coupling data of each horizontal analysis unit after stratification correction is multiplied by the corresponding strength growth coefficient to obtain an initial strength value of the unit, and the initial strength values of all horizontal analysis units in the same longitudinal detection layer are weighted and averaged;

[0123] The average strength value of the longitudinal detection layer is subjected to spatial continuity verification, and the deviation rate of the average strength values of adjacent layers is calculated;

[0124] The coupling data in each horizontal analysis unit is re-corrected based on the deviation rate, and when the deviation rate decreases to within the preset range, the re-correction is stopped, and the concrete strength of the detection part is obtained.

[0125] In this embodiment, the annular sector region is determined according to the distribution density of the ultrasonic detection points, and it is ensured that each unit contains at least 3 groups of effective coupling data.

[0126] In this embodiment, the coupling data in each transverse analysis unit is corrected based on the direction, including: when the ultrasonic propagation direction is parallel to the casting bedding direction, the coupling data is multiplied by a bedding correction coefficient of 1.02-1.05; when the propagation direction is perpendicular to the bedding direction, the coupling data is multiplied by a bedding correction coefficient of 0.95-0.98; when the propagation direction is at an angle of 45° with the bedding direction, the coupling data is multiplied by a bedding correction coefficient of 0.98-1.02. The correction coefficient is dynamically adjusted according to the bonding strength detection value of the bedding interface.

[0127] In this embodiment, the weighted average is, for example, the weight is determined according to the amount of effective data contained in each unit, and the weight is increased by 3%-5% for each increase of 1 group of data;

[0128] The beneficial effects of the above technical solutions are: by dividing the unit according to the bedding direction and correcting the coupling data, the influence of the bedding direction on the strength evaluation is eliminated; by dynamically calling the age growth curve, the limitation of the fixed coefficient is avoided; by combining the spatial continuity verification and the deviation rate re-correction, the local data anomaly is effectively avoided, and the overall accuracy and consistency of the pier column concrete strength detection are significantly improved.

[0129] Embodiment 8:

[0130] The embodiment of the present application provides an ultrasonic-rebound comprehensive detection method for the concrete strength of a bridge pier column, calls a corresponding curve in a preset database based on a difference value, determines a corresponding strength growth coefficient based on the curve, and includes the following steps:

[0131] When the difference value is negative, an early growth curve corresponding to the cementitious material variety is called from the preset database, and a coefficient value corresponding to the actual age is intercepted;

[0132] When the difference value is positive, a late growth curve is called from the preset database;

[0133] The coefficient value corresponding to the actual age is determined as the corresponding strength growth coefficient based on the early growth curve and the late growth curve.

[0134] In the embodiment, the preset database refers to a preset strength growth coefficient database, which refers to a set of characteristic curves of the strength of concrete changing with age under different curing environment parameters (temperature 20-35℃, relative humidity 50%-95%) with the commonly used concrete binder varieties (such as Portland cement, ordinary Portland cement, etc.) in bridge engineering as the classification dimension. Each curve corresponds to a strength growth coefficient sequence of a specific binder under specific curing conditions from the completion of pouring to 180 days of age, and the coefficient value is generated based on the standard curing test data and engineering measured data of the same batch of concrete test blocks by statistical fitting, and includes a correction sub-library for different admixture (fly ash, slag, etc.) contents.

[0135] Embodiment 9:

[0136] The embodiment of the present application provides an ultrasonic-rebound comprehensive detection system for the strength of bridge pier concrete, which comprises:

[0137] An ultrasonic data acquisition module is configured to acquire ultrasonic propagation velocity data of the detection part of the bridge pier;

[0138] A rebound data acquisition module is configured to acquire rebound value data of the detection part of the bridge pier;

[0139] A data processing module is configured to couple the ultrasonic propagation velocity data and the rebound value data, and determine the strength of the concrete of the detection part in combination with the pouring stratification direction of the bridge pier concrete, the strength growth coefficient corresponding to the curing age.

[0140] The above technical solution has the following beneficial effects: by precisely matching the spatial positions of the ultrasonic detection points and the rebound measurement areas, in combination with layered correction and regional calibration, considering the influence of the pouring stratification direction and the dynamic age coefficient, the data correlation is enhanced; through fine coupling processing, the interference of structural and material factors is reduced, and the accuracy and stability of the detection of the strength of the bridge pier concrete are significantly improved.

[0141] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for ultrasonic-rebound-combined detection of concrete strength of a bridge pier column, characterized in that, The method comprises the following steps: Step 1: obtaining ultrasonic propagation velocity data of a bridge pier column to-be-detected part; Step 2: obtaining rebound value data of the bridge pier column to-be-detected part; Step 3: coupling the ultrasonic propagation velocity data and the rebound value data, and determining the concrete strength of the to-be-detected part in combination with the pouring stratification direction of the bridge pier column concrete and the strength growth coefficient corresponding to the curing age; The coupling of the ultrasonic propagation velocity data and the rebound value data comprises: dividing the longitudinal detection layers according to the pouring stratification direction of the bridge pier column concrete, each layer corresponding to an independent velocity correction coefficient, and performing layered correction on the ultrasonic propagation velocity data based on the velocity correction coefficient; dividing the rebound measurement area into preset level areas according to the surface carbonization depth, and performing area calibration on the rebound value data; establishing an ultrasonic-rebound data correlation matrix based on the corrected ultrasonic propagation velocity data and the calibrated rebound value data, wherein the row dimension of the matrix corresponds to the spatial coordinates of the ultrasonic detection points, and the column dimension corresponds to the spatial coordinates of the rebound measurement area; calculating the coordinate deviation value of the spatial coordinates of the ultrasonic detection points and the spatial coordinates of the rebound measurement area, and determining the correlation weight based on the coordinate deviation value; combining the corrected ultrasonic propagation velocity data and the calibrated rebound value data based on the correlation weight to obtain coupled data; determining the concrete strength of the to-be-detected part in combination with the pouring stratification direction of the bridge pier column concrete and the strength growth coefficient corresponding to the curing age, comprising: dividing the horizontal analysis units according to the pouring stratification direction for the coupled data, wherein each horizontal analysis unit corresponds to a ring-shaped area of a longitudinal detection layer; analyzing the direction of the coupled data in each horizontal analysis unit; correcting the coupled data in each horizontal analysis unit based on the direction; obtaining the actual curing record of the bridge pier column concrete, and determining the difference between the detection age and the standard curing age; based on the difference, retrieving the corresponding curve in the preset database, and determining the corresponding strength growth coefficient based on the curve; multiplying the coupled data of each horizontal analysis unit after stratification correction by the corresponding strength growth coefficient to obtain unit initial strength values, and simultaneously, performing weighted average on the initial strength values of all horizontal analysis units in the same longitudinal detection layer; performing spatial continuity verification on the average strength values of the longitudinal detection layers, and calculating the deviation rate of adjacent layer average strength values; based on the deviation rate, re-correcting the coupled data in each horizontal analysis unit, and when the deviation rate decreases to within a preset range, stopping re-correction to obtain the concrete strength of the to-be-detected part.

2. The method of claim 1, wherein, The method for obtaining the ultrasonic propagation velocity data of the bridge pier column to-be-detected part comprises: arranging a preset number of ultrasonic transducer arrays at different heights of the to-be-detected part of the bridge pier column in a ring shape, each group of ultrasonic transducer arrays comprising a transmitting transducer and a receiving transducer; dividing a preset number of detection points at equal angle intervals in the ring-shaped area covered by each group of ultrasonic transducer arrays, each detection point corresponding to a group of aligned combinations of transmitting transducers and receiving transducers; The pulse excitation signal is applied to the transmitting transducer, and a frequency of the pulse excitation signal is determined according to a maximum particle size of coarse aggregate of the bridge pier concrete; The ultrasonic propagation time from the transmitting transducer to the receiving transducer is recorded based on the ultrasonic signal received by the receiving transducer after penetrating the concrete, and then the ultrasonic propagation time of each detection point is obtained; The ultrasonic propagation speed data is calculated according to a straight-line distance between the transmitting transducer and the receiving transducer and the measured ultrasonic propagation time.

3. The method of claim 2, wherein, The rebound value data of the bridge pier detection part is obtained, including: In the bridge pier detection part, a ring-shaped area corresponding to the height of the ultrasonic transducer array is divided into the same number of rebound measurement areas as the detection points, and the spatial position deviation of each rebound measurement area and the corresponding ultrasonic detection point is not more than a preset deviation value; The preset rebound instrument is continuously hit for a preset number of times in each rebound measurement area, and the angle between the axis of the preset rebound instrument and the normal direction of the surface of the bridge pier is not more than a preset angle during the continuous hitting process, and the rebound value after each hitting in the continuous hitting process is recorded; The abnormal values caused by the deviation of the hitting position are removed from the rebound values, and the average value of the remaining effective rebound values is taken as the rebound value data of the corresponding rebound measurement area.

4. The method of claim 1, wherein, The longitudinal detection layers are divided according to the layering direction of the bridge pier concrete pouring, each layer corresponds to an independent speed correction coefficient, and the ultrasonic propagation speed data is corrected layer by layer based on the correction coefficient, including: The layering record during the pouring of the bridge pier concrete is obtained, and the deviation rate of the actual thickness and the design thickness of each longitudinal detection layer is determined; The ultrasonic propagation speed data in each longitudinal detection layer is analyzed for dispersion, and the ratio of the standard deviation to the average value is calculated; when the ratio exceeds a preset percentage, the layer data is reselected, and the abnormal speed value deviating from and exceeding the average value by a preset multiple standard deviation is removed to recalculate the correction coefficient; The ultrasonic propagation speed data is corrected layer by layer based on the correction coefficient.

5. The method of claim 4, wherein, The deviation rate of the actual thickness and the design thickness of each longitudinal detection layer is determined, including: When the deviation rate is within a preset deviation rate, a basic correction coefficient is used; Or, when the deviation rate exceeds the preset deviation rate, the correction coefficient is additionally adjusted by a preset proportion for each increase of the preset deviation rate based on the basic correction coefficient.

6. The method of claim 1, wherein, Based on the difference value, a corresponding curve is called from a preset database, and a corresponding strength growth coefficient is determined based on the curve, including: When the difference value is negative, an early growth curve corresponding to the cementitious material variety is called from the preset database, and a coefficient value corresponding to the actual age is intercepted; When the difference value is positive, a late growth curve is called from the preset database; The coefficient value corresponding to the actual age is determined as the corresponding strength growth coefficient based on the early growth curve and the late growth curve.

7. An ultrasonic-rebound-composite system for performing the method of any one of claims 1-6, wherein, It includes: An ultrasonic data acquisition module: obtaining ultrasonic propagation speed data of a bridge pier detection part; A rebound data acquisition module: obtaining rebound value data of a bridge pier detection part; The data processing module: coupling processing the ultrasonic propagation velocity data and the rebound value data, combining the pouring stratification direction of the bridge pier column concrete and the strength growth coefficient corresponding to the curing age to determine the concrete strength of the detected part.

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