CN115404920B - Foundation pile detection method and system - Google Patents
Foundation pile detection method and system Download PDFInfo
- Publication number
- CN115404920B CN115404920B CN202210938356.4A CN202210938356A CN115404920B CN 115404920 B CN115404920 B CN 115404920B CN 202210938356 A CN202210938356 A CN 202210938356A CN 115404920 B CN115404920 B CN 115404920B
- Authority
- CN
- China
- Prior art keywords
- foundation pile
- wave
- excitation
- pile
- stress
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 43
- 230000005284 excitation Effects 0.000 claims abstract description 148
- 230000007547 defect Effects 0.000 claims abstract description 48
- 230000001052 transient effect Effects 0.000 claims abstract description 32
- 229910052704 radon Inorganic materials 0.000 claims description 48
- SYUHGPGVQRZVTB-UHFFFAOYSA-N radon atom Chemical compound [Rn] SYUHGPGVQRZVTB-UHFFFAOYSA-N 0.000 claims description 48
- 230000009466 transformation Effects 0.000 claims description 28
- 238000001914 filtration Methods 0.000 claims description 18
- 238000006243 chemical reaction Methods 0.000 claims description 15
- 238000011144 upstream manufacturing Methods 0.000 claims description 13
- 239000011159 matrix material Substances 0.000 claims description 6
- 238000010276 construction Methods 0.000 claims description 5
- 238000003491 array Methods 0.000 claims description 4
- 238000000034 method Methods 0.000 description 31
- 238000005259 measurement Methods 0.000 description 17
- 238000004458 analytical method Methods 0.000 description 16
- 230000004044 response Effects 0.000 description 14
- 230000005540 biological transmission Effects 0.000 description 9
- 230000002950 deficient Effects 0.000 description 9
- 238000002474 experimental method Methods 0.000 description 7
- 238000012545 processing Methods 0.000 description 6
- 230000000644 propagated effect Effects 0.000 description 6
- 230000008569 process Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000002441 reversible effect Effects 0.000 description 4
- 230000035939 shock Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000001788 irregular Effects 0.000 description 3
- 230000001902 propagating effect Effects 0.000 description 3
- 239000002689 soil Substances 0.000 description 3
- 230000001133 acceleration Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000007689 inspection Methods 0.000 description 2
- 230000000737 periodic effect Effects 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 230000000007 visual effect Effects 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 238000002591 computed tomography Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 238000001338 self-assembly Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D33/00—Testing foundations or foundation structures
Abstract
A foundation pile detection method is used for detecting defects of a foundation pile in service and relates to the field of foundation pile detection. Comprising the following steps: setting an excitation point/excitation surface on a first side of a foundation pile; applying a transient excitation force to the excitation point/surface to generate a stress wave and transmitting the stress wave to a second side of the foundation pile; the stress wave is received at least two signal points on the second side of the foundation pile to determine the presence of foundation pile defects and their location. According to the invention, by collecting the stress wave signals at multiple signal points, the stress wave can propagate upwards and downwards, and for an uplink wave, the higher the signal point is, the longer the time for receiving the stress wave is, the backward shift of the peak position of the first wave appears on a reflected wave graph; for the downgoing wave, the time for the sensor with higher position to receive the stress wave is shorter, and the reflected wave graph shows that the peak position of the head wave moves forward, so that a basis for separating the upgoing wave from the downgoing wave in the stress wave is provided, and foundation pile defects are analyzed. The invention also relates to a foundation pile detection system.
Description
Technical Field
The invention relates to the field of foundation pile detection, in particular to a foundation pile detection method and system.
Background
The pile foundation is an important structural component of bridge engineering, and is used for transmitting the dead weight of the upper structure and the load born by the dead weight of the upper structure to the pile periphery and the rock soil at the bottom of the pile through the combined action of pile soil, and if the pile body has defects, the bearing capacity of the foundation pile is not easily exerted, so that the quality detection of the foundation pile is required to be carried out once before the completion of the bridge.
After the foundation pile is in service, the existing detection mechanism is usually used for detecting only the road on the upper side, and the quality condition of the foundation pile is rarely tracked and detected, so that the foundation pile cannot be guaranteed to be free from defects after the service, and the bearing capacity meets the design requirement. The related data show that most of the existing bridge structural damage is related to foundation pile defects;
due to the existence of the bridge superstructure, the traditional existing foundation pile detection technology has little effect and even cannot be developed. High strain, cross-hole ultrasonic and other technologies cannot be used for carrying out detection work in the existing foundation piles; the core drilling method is time-consuming and labor-consuming, and can only start coring on the bridge deck, and construction is unnecessary; other geophysical prospecting technologies, such as cross-hole CT scanning, side-hole transmission method, geological radar method and the like, are theoretically feasible, but in practice, the interference influence of surrounding soil of piles is large, and the effect is unsatisfactory. Several expert scholars at home and abroad improve the low strain method, but the waveform analysis is extremely complex due to the mutual superposition of the up-and-down traveling waves. The dual-speed method can theoretically separate up and down traveling waves, but the precondition is too ideal, the single signal analysis is poor in representativeness, and the actual detection result is often not ideal.
Therefore, the importance of the periodic inspection of existing bridge foundation piles is self-evident; there is an urgent need for a detection scheme that has less damage to foundation pile structures and has visual and ideal detection results.
Disclosure of Invention
The invention aims to overcome at least one defect of the prior art, and provides a foundation pile detection method and system for solving the detection difficulty of low-strain measurement in-service foundation piles.
The technical scheme adopted by the invention is as follows: a foundation pile detection method for detecting defects of a foundation pile in service, comprising:
setting an excitation point/excitation surface on a first side of a foundation pile;
applying a transient excitation force to the excitation point/surface to generate a stress wave and transmitting the stress wave to a second side of the foundation pile;
the stress waves are received at least two signal points on the second side of the foundation pile and all stress waves are analyzed to derive structural characteristics of the foundation pile and to determine the presence of foundation pile defects and their location. When the traditional low-strain method is used for measuring foundation piles, the foundation piles which are just poured, molded and solidified are often measured, the top end structure of the foundation piles is often easy to obtain the upper end surface, so that the measurement is carried out through knocking, but when the foundation piles in various service are detected, the top ends of the foundation piles are often loaded with various structures, such as pier columns and the like; when the foundation pile is required to be detected, the corresponding top end excitation surface or working surface cannot be obtained well, so that the invention improves the top end working surface which is close to the impossible application into an excitation point or an excitation surface arranged on one side of the foundation pile by improving the measuring mode of the low strain method, and meanwhile, under the condition that the measuring formula of the low strain method is not suitable for excitation of one side excitation surface, the invention further reduces the interference factor by adopting the mode of collecting the reflection signals of stress waves through multiple points, and the traditional low strain method depends on the display of a single curve, so that the interference misjudgment except the response of the foundation pile exists; when a specific stress wave is measured, for a pile foundation with a free pile top, after transient exciting force is applied, hemispherical waves are generated on an exciting point, after the hemispherical waves are propagated in a certain space, the hemispherical waves are propagated upwards or downwards in the form of plane waves, so that the stress waves can be propagated upwards along a pier column and downwards along a foundation pile, and are reflected when the hemispherical waves pass through the top surface of the pier column or the bottom surface of the foundation pile, so that the direction of the stress waves is turned over, and the energy of the stress waves is gradually consumed in the propagation process; because of the spatial position relation between the foundation pile and the sensor, the stress wave reflected by the pile body and the pile bottom of the foundation pile always goes upward, so that the upward wave signal contains the structural characteristic information of the foundation pile and is the result of pursuit of the invention; as the stress wave (including the head wave) is received by the sensor in the process of upwards transmitting the stress wave, the higher the position is, the longer the transmission distance of the sensor is, the longer the time for receiving the stress wave (head wave) is, and the position of the wave peak on the reflected wave graph is backward; in the process of downward propagation of the stress wave, the stress wave is received by the sensor, the propagation distance of the sensor with higher position is shorter, the time for receiving the stress wave is shorter, and the reflected wave graph shows that the wave crest position moves forward. Since the sensors are equidistantly arranged along the height direction of the pier, the backward/forward movement time of the wave crest between the adjacent curves is consistent, and the sensor is further expressed as follows on the low-strain profile: the reflected waves of the same pile body structure in the curves form reflected wave homophase shafts with the same slope. The stress wave properties can be further analyzed by the sign of the slope, namely: the upward wave is obtained when the in-phase axis slope on the low strain section is negative; and the positive phase axis slope on the low-strain profile is the downlink wave. The positive and negative differences of the slopes of the same phase shafts are the characteristic differences of the uplink and downlink waves, and the differences are the basis for separating the uplink and downlink waves; and the separated uplink wave is a foundation for analyzing the defect characteristics of the pile body of the foundation pile and the position of the pile bottom.
Further, the profile data includes a profile, the profile being a two-dimensional graph, the axial data of the profile including: the depth parameter and the number of signal points are used for displaying a low-strain curve acquired by the sensors arranged on the plurality of signal points in the same time period, wherein the low-strain curve comprises reflection impedance encountered by stress waves when the foundation pile structure propagates, and the reflection impedance is represented as a same phase axis in a sectional view.
Preferably, setting the excitation point/excitation surface includes:
when a horizontal plane is arranged in the direction vertical to the height direction of the foundation pile, setting the horizontal plane as an excitation surface, and setting the drop point of the excitation force on the excitation surface as a transient excitation point;
when the foundation pile structure does not have the horizontal plane, a measuring height is positioned, an excitation groove with the bottom being flush with the measuring height is formed in the measuring height position of the foundation pile, the bottom surface of the excitation groove is set to be an excitation surface, and the drop point of the excitation force on the excitation surface is set to be a transient excitation point.
In this embodiment, by setting a conventional horizontal plane, it is generally meant that a structure protruding from one side of the foundation pile, such as a tie beam, a pier top surface, or a bottom surface, is often provided with a horizontal plane that can be directly excited, an excitation point can be directly set on the horizontal plane, and after setting an excitation surface/excitation point, the height data of the excitation surface can be directly obtained by analysis in a field measurement manner or in subsequent section data.
Preferably, determining the transient excitation point/excitation surface includes:
flush the transient excitation point/excitation surface height on a first side of the foundation pile with the lowest sensor height on a second side thereof; and/or, enabling the direction of the transient exciting force to be perpendicular to the height direction of the foundation pile. In this embodiment, the stress point of the exciting force is flush with the position of the first sensor, so that the exciting force can be instantly obtained by collecting the impedance resonating at the exciting point by the sensor, a plurality of reflected impedances passing through the depth of 0m can be directly observed on the sectional view, the experimenter can directly observe the signal change based on the exciting point conveniently, the starting point of the observation window can be directly defined, and correspondingly, if the first sensor and the exciting point are not at the same height, the reflected impedance at the exciting point has certain delay without skipping or intercepting the display space occupied by the delay, so that the method is more suitable for the use habit of the operator; when the direction of the exciting force is set to be the same as the height direction of the foundation pile, the stress wave transmission direction of the foundation pile corresponds to the distribution of the sensor in the height direction, so that the stress wave signal can be converted into corresponding in-phase axis distribution.
Preferably, setting a transient excitation point/excitation surface on a first side of the foundation pile comprises:
knocking the foundation pile at a first side of the foundation pile at a preset average speed and/or a preset excitation force so as to enable the foundation pile to generate stress waves and transmit the stress waves to a second side of the foundation pile, or knocking the same position of the foundation pile at different average speeds and/or different excitation forces each time so as to enable the foundation pile to generate stress waves and transmit the stress waves to the second side of the foundation pile;
and/or;
the foundation pile is hit each time at a different location on the first side of the foundation pile, so that the foundation pile generates a stress wave and transmits it to the second side of the foundation pile. In this embodiment, the excitation point or the excitation surface is set on the first side to generate the stress wave, and the first side refers to a proper position for excitation is selected on one side surface of the foundation pile, so that a working surface for excitation is set on the excitation, so that the corresponding excitation device can provide excitation force, and the working surface only needs to set the height on the side surface of the foundation pile, and is provided with a groove structure, so that the excitation surface can further measure the height, and a specific theoretical working surface reference can be provided for the subsequent stress wave during measurement, so that the method is more suitable for the detection of the structure of the foundation pile in service; the excitation force can be applied according to a preset average speed to strike the excitation surface or a preset acceleration, so that the stress wave pattern in excitation can be directly acquired without further assistance of other signal amplifiers and other elements; in this embodiment, the method further includes: by setting a plurality of different exciting forces, the stress wave impedance positions of stress waves with different degrees of elevation on the same depth position can be obviously compared when the same foundation pile is measured, clutter interference reflection is eliminated, the different-degree knocking exciting force can be selected according to actual conditions in experiments, and the invention aims to provide a reference working scheme which is not used as a specific scheme of a specific measurement experiment defined by the invention.
Preferably, receiving said stress wave at least two signal points on the second side of the foundation pile comprises: 30-60 signal points are equidistantly arranged along the height direction of the foundation pile, and the distance between two adjacent signal points is 10-30 cm. In one embodiment of the present invention, considering the way of separating the up-down traveling wave, the present invention further sets the receiving positions of the signal points along the height direction, and when a plurality of signal points receive the corresponding stress waves, a certain time difference is provided, the time difference is determined by the size of the interval, and when the interval is set to be equidistant, it can further ensure that: when a low-strain section formed by combining a plurality of low-strain detection units is arranged, stress wave signals received by a plurality of signal points are displayed as in-phase axes with downward trend on a section view, the slope is negative, stress waves reflected back after being transmitted by a pile body are also uplink waves, the same principle can be obtained, stress reflected waves at the same pile body position can form in-phase axes on the low-strain section view, and the slope is the same as that of the in-phase axes of the first wave; when one side of the foundation pile is provided with other combined structures, such as a bent cap, when stress waves propagate upwards, the stress waves are reflected by the bent cap, the reflected waves are received by the sensor at the highest position, then are sequentially received by the sensor from high to low, and the time for the sensor at the higher position to receive the bent cap reflected waves is shorter, so that the reflected wave peaks of the bent cap are shown to move forwards on a reflected wave graph. Forming an upward-oriented homophase axis on the low-strain profile, wherein the slope is positive; therefore, a plurality of signal points equidistantly arranged along the height direction realize the coaxial display of a plurality of stress wave measurements or low strain curves on the sectional view, and have obvious in-phase slope difference, and the difference is the basis for separating up-and-down traveling waves.
Preferably, the stress wave is received on a second side of the foundation pile and the stress wave is analyzed to determine structural characteristics of the foundation pile, comprising:
receiving the stress wave at the second side of the foundation pile, performing analog-to-digital conversion and recording a speed signal of the stress wave;
combining the speed signals recorded by all the signal receiving points into matrix arrays, and integrating the matrix arrays into low-strain profile data through program conversion;
determining structural characteristics of the foundation pile by analyzing the low strain profile data, comprising:
the section data comprise a low-strain section chart and a plurality of uplink and downlink in-phase shafts on the same low-strain section chart, and if the uplink in-phase shafts have downlink in-phase shafts with opposite slopes and are close to each other until the downlink in-phase shafts are intersected, the corresponding depth of the uplink in-phase shafts is used for representing the structural position of the pile body;
and/or carrying out Radon transformation on the low-strain profile data to separate an uplink wave profile, and analyzing the defect characteristic of the pile body or the position of the pile bottom according to the reflection wave phase axis in the uplink wave profile. In this embodiment, after the stress is obtained at the signal point, the cross-sectional view is obtained through the radon transformation, and the structural characteristics of the pile body are further analyzed on the basis of the cross-sectional view, wherein, on the basis of the above-mentioned multiple stress wave signals which are arranged downwards along the same phase axis, the existence of the up-down traveling wave is simultaneously displayed on the cross-sectional view, which is unfavorable for the analysis of the foundation pile structure, so the invention further considers the property of the radon transformation, and transforms the seismic data in the time domain into tau-p domain (tau is the stress wave double-way travel time, p is the phase axis slope) through the linear radon transformation, and since the up-traveling wave and the down traveling wave in the data are approximately linear and have the slopes of opposite signs, the data "will be represented as rays with the same slope and passing through the origin" in the tau-p domain. And then the rays on the left and right sides of the origin are cut off by a simple filtering operator. After filtering, the needed data are reserved, the ground vibration data with only the uplink wave are obtained through inverse transformation, then the corresponding uplink wave profile data are obtained through radon inverse transformation, the depth corresponding to the uplink wave reflection phase axis in each uplink wave profile is reflected, different pile body structures are reflected, and the structural characteristics of the pile body can be obtained by combining the construction parameter comparison before the pile body.
Further, analyzing the stress wave includes:
according to the stress wave signal when the transient excitation device applies the transient excitation force on the foundation pile, carrying out local window clipping to obtain a periodic response signal;
based on the response signals, converting the response signals into digital signals in an analog-to-digital mode, and converting the digital signals into seismic profile sgy data;
performing radon transformation on the seismic profile sgy data to isolate up-going wave profile data;
and converting the uplink wave profile data into an uplink wave profile diagram through radon inversion so as to obtain the structural characteristics of the foundation pile.
Based on the foundation pile detection method, in order to further implement the method, the invention further comprises a foundation pile detection system, which comprises:
excitation generating device: for applying a transient excitation force to a first side of the foundation pile to cause the foundation pile to respond by generating a stress wave signal;
excitation receiving device: and the stress wave signals are used for receiving the transient exciting force at a plurality of signal points on the second side of the foundation pile, and analyzing the structural characteristics of the foundation pile.
Preferably, the excitation receiving device includes: the device comprises a sensor, an analog-to-digital conversion module and a data processing module;
a sensor: the analog-to-digital conversion module is connected with the second side of the foundation pile and used for receiving an electric signal and performing analog-to-digital conversion on the electric signal to obtain a digital signal;
The analog-to-digital conversion module is connected with the data processing module and is used for receiving the digital signals and analyzing the digital signals to obtain the section data, and the defects of the foundation pile and the positions of the defects are obtained according to the section data.
Preferably, the analog-to-digital conversion module includes a sgy module, a radon module, and a display module, where the sgy module is configured to convert the digital signal into sgy profile data, the radon module is configured to integrate the sgy profile data into a rectangular array, and after the matrix array is subjected to radon conversion by the radon module, the matrix array is divided into an uplink reflected wave signal profile and a downlink reflected wave signal profile, and the display module is configured to display the uplink reflected wave signal profile and the downlink reflected wave signal profile.
Preferably, the excitation generating means comprises an excitation hammer for applying an excitation force on the foundation pile for obtaining a stress wave signal on the second side of the foundation pile.
Preferably, the foundation pile is provided with a signal point, the excitation measuring device further comprises a sensor and a dynamic side instrument, the sensor is arranged on the signal point, the dynamic side instrument is provided with an analog-to-digital conversion module, and the dynamic side instrument is connected with the data processing module and the display module and is used for storing and displaying profile data after excitation.
Compared with the prior art, the invention has the beneficial effects that:
1) The detection method or the detection system is selected to excite on the pier column or the tie beam, has lower requirement on the working surface, and is better suitable for detecting the existing or service foundation piles;
2) The measurement is carried out on a plurality of signal points, and by controlling the position distribution of each signal point, stress waves generated by exciting force can collect reflected wave signals at a plurality of signal points at one time, so that accidental errors caused by experiments can be avoided, particularly, the arrangement of equidistant distribution along foundation piles is realized, a plurality of signals display homophase shafts with the same trend on a low-strain section view, and the view is simpler and more visual; the rule of the reflected wave signal can be intuitively and clearly observed, or the defect position of the foundation pile can be directly obtained;
separating up-down traveling waves based on Radon transformation, and eliminating down-traveling wave signal interference caused by upper structures (capping beams, tie beams, pier columns and the like) to the greatest extent; meanwhile, the uplink wave signal is reserved, and the reflected wave signal analysis can be performed more directly.
Drawings
Fig. 1 is a flowchart of a foundation pile detection method according to the present invention.
Fig. 2 is a flow chart of a stress wave signal analysis method of a foundation pile detection method of the present invention.
Fig. 3 is an original wave-section view of an exemplary complete foundation pile of the present invention.
Fig. 4 is a structural view of a defective foundation pile according to the present invention.
Fig. 5 is an original wave-section view of a complete foundation pile of the present invention.
Fig. 6 is a Radon transform domain diagram of fig. 5.
Fig. 7 is a cross-sectional view of the filtered upstream wave of fig. 5.
Fig. 8 is a cross-sectional view of the downstream wave of fig. 5 after filtering.
Fig. 9 is an original wave-sectional view of a defective foundation pile of the present invention.
Fig. 10 is a plot of the radon transform domain of fig. 9.
Fig. 11 is an upstream wave-section view of fig. 10 after filtering and inverse radon transformation.
Fig. 12 is a down-going wave-section view of fig. 10 after filtering and inverse radon transformation.
Fig. 13 is an original wave-section view of a broken pile pattern.
Fig. 14 is a plot of the radon transform domain of fig. 13.
Fig. 15 is a down-going wave-section view of fig. 13 after filtering and inverse radon transformation.
Fig. 16 is an upstream wave-section after filtering and inverse radon transform.
Fig. 17 is an original wave-sectional view of the expanded diameter model.
FIG. 18 is an upstream wave-section after radon transformation, filtering, and radon inverse transformation.
Detailed Description
The drawings are for illustrative purposes only and are not to be construed as limiting the invention. For better illustration of the following embodiments, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the actual product dimensions; it will be appreciated by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.
Example 1
As shown in FIG. 1, a foundation pile inspection method for inspecting a service foundation pile for defects includes
Setting an excitation point/excitation surface on a first side of a foundation pile;
applying a transient excitation force to the excitation point/surface to generate a stress wave and transmitting the stress wave to a second side of the foundation pile;
the stress wave is received at least two signal points on the second side of the foundation pile and the stress waves received by all sensors are analyzed to derive structural characteristics of the foundation pile and to determine the presence of foundation pile defects and their location. In this embodiment, when a foundation pile is measured by a conventional low-strain method, an upper end face is often easily obtained by measuring a foundation pile which is just molded and solidified, so that the measurement is performed by knocking, but when various service foundation piles are detected, the top end of the foundation pile is often loaded with various structures, such as bridges, and when the foundation pile is required to be detected, a corresponding top end excitation face or a working face cannot be obtained well, so that the inventor improves a top end working face which is close to an impossible application into an excitation point or an excitation face arranged on one side of the foundation pile by improving a measurement mode of the low-strain method, and meanwhile, in the case that a measurement formula of the low-strain method is not applicable to excitation of one side, the invention further reduces the interference factors by adopting a mode of collecting stress wave reflection signals through multiple points, aiming at the defect that the corresponding conventional low-strain method depends on a single curve, and by adopting a measurement mode of receiving stress waves through multiple signal points under the condition of misjudgment except for foundation pile response; when a specific stress wave is measured, after a transient excitation force is applied to a pile foundation of a pile top self-assembly, hemispherical waves are generated on an excitation point, and after a certain time and space are propagated, the hemispherical waves are propagated upwards or downwards in the form of plane waves, so that the stress waves can be propagated upwards along a pier column and downwards along a foundation pile, and are emitted when passing through the top surface or the bottom surface of the foundation pile, so that the direction of the stress waves is turned over, and the stress waves are divided into up-and-down traveling waves according to the transmission directions of the stress waves, including the transmission directions after reflection; the upstream wave signal contains foundation pile structure characteristic information, and is the result sought by the present invention. As the stress wave (including the head wave) is received by the sensor in the process of upwards propagating, the higher the position is, the longer the propagation distance of the sensor is, the longer the time for receiving the stress wave (head wave) is, and the position of the wave peak on the reflected wave graph is backward; in the process of downward propagation of the stress wave, the stress wave is received by the sensor, the propagation distance of the sensor with higher position is shorter, the time for receiving the stress wave is shorter, and the reflected wave graph shows that the wave crest position moves forward. Since the sensors are equidistantly distributed along the height direction of the pier stud, the backward/forward movement time of the wave crest between the adjacent curves is consistent, and the sensor is further expressed as follows on the low-strain profile: the reflected waves of the same pile body structure in the curves form reflected wave homophase axes with the same slope. The stress wave properties can be further analyzed by positive and negative slope, namely: the upward wave is obtained when the in-phase axis slope on the low strain section is negative; and the positive phase axis slope on the low-strain profile is the downlink wave. The positive and negative differences of the slopes of the same phase axis are the characteristic differences of the uplink and downlink waves, and the differences are the basis for separating the uplink and downlink waves; and the separated uplink wave is a foundation for analyzing the defect characteristics of the pile body of the foundation pile and the position of the pile bottom.
Further, a first side and a second side of the foundation pile are defined, and at least a common edge exists between the first side and the second side. In this embodiment, the defining manner of the first side and the second side distinguishes the positions of the signal point and the excitation point in the horizontal axial direction, so that a certain length difference exists in the horizontal axial direction; the horizontal axial direction is relative to the height direction of the foundation pile; wherein at least the presence of a common edge comprises:
when the integral structure of the foundation pile is a square structure or an irregular straight surface, the first side is one side surface of the square structure or the irregular straight surface, and the second side is the other side surface of the square structure or the irregular straight surface;
when the integral structure of the foundation pile is cylindrical or curved, the first side is one part of the cylindrical side or curved, and the second side is the other part of the cylindrical side or curved.
Further, the profile data includes a profile, the profile being a two-dimensional graph, the axial data of the profile including: the depth parameter and the number of signal points are used for displaying response curves acquired by sensors arranged on a plurality of signal points in the same time period, wherein the response curves comprise reflection impedance encountered by stress waves when the foundation pile structure propagates.
Further, setting the excitation point/excitation surface includes:
when a horizontal plane is arranged in the direction vertical to the height direction of the foundation pile, setting the horizontal plane as an excitation surface, and setting the drop point of the excitation force on the excitation surface as a transient excitation point;
when the foundation pile structure does not have the horizontal plane, a measuring height is positioned, an excitation groove with the bottom being flush with the measuring height is formed in the measuring height position of the foundation pile, the bottom surface of the excitation groove is set to be an excitation surface, and the drop point of the excitation force on the excitation surface is set to be a transient excitation point. In this embodiment, by setting a conventional horizontal plane, it is generally meant that a structure protruding from one side of the foundation pile, such as a tie beam, a pier top surface, or a bottom surface, is often provided with a horizontal plane that can be directly excited, an excitation point can be directly set on the horizontal plane, and after setting an excitation surface/excitation point, the height data of the excitation surface can be directly obtained by analysis in a field measurement manner or in subsequent section data.
Preferably, determining the transient excitation point/excitation surface includes:
flush the transient excitation point/excitation surface height on a first side of the foundation pile with the lowest sensor height on a second side thereof; and/or, the direction of the transient excitation force is flush with the height direction of the foundation pile. In this embodiment, the stress point of the exciting force is flush with the position of the first sensor, so that the exciting force can be instantly obtained by collecting the impedance resonating at the exciting point by the sensor, a plurality of reflected impedances passing through the depth of 0m can be directly observed on the sectional view, the experimenter can directly observe the signal change based on the exciting point conveniently, the starting point of the observation window can be directly defined, and correspondingly, if the first sensor and the exciting point are not at the same height, the reflected impedance at the exciting point has certain delay without skipping or intercepting the display space occupied by the delay, so that the method is more suitable for the use habit of the operator; when the direction of the exciting force is set to be the same as the height direction of the foundation pile, the stress wave transmission direction of the foundation pile corresponds to the distribution of the sensor in the height direction, so that the stress wave signal can be converted into corresponding in-phase axis distribution.
Preferably, setting a transient excitation point/excitation surface on a first side of the foundation pile comprises:
knocking the foundation pile at a first side of the foundation pile at a preset average speed and/or a preset excitation force so that the foundation pile generates stress waves and transmits the stress waves to a second side of the foundation pile, or knocking the same position of the foundation pile at different average speeds and/or different excitation forces each time so that the foundation pile generates stress waves and transmits the stress waves to the second side of the foundation pile;
and/or;
the foundation pile is hit each time at a different location on the first side of the foundation pile, so that the foundation pile generates a stress wave and transmits it to the second side of the foundation pile. In this embodiment, the excitation point or the excitation surface is set on the first side to generate the stress wave, and the first side refers to a proper position for excitation is selected on one side surface of the foundation pile, so that a working surface for excitation is set on the excitation, so that the corresponding excitation device can provide excitation force, and the working surface only needs to set the height on the side surface of the foundation pile, and is provided with a groove structure, so that the excitation surface can further measure the height, and a specific theoretical working surface reference can be provided for the subsequent stress wave during measurement, so that the method is more suitable for the detection of the structure of the foundation pile in service; the excitation force can be applied according to a preset average speed to strike the excitation surface or a preset acceleration, so that the stress wave pattern in excitation can be directly acquired without further assistance of other signal amplifiers and other elements; in this embodiment, the method further includes: by setting a plurality of different exciting forces, the stress wave impedance positions of stress waves with different degrees of elevation on the same depth position can be obviously compared when the same foundation pile is measured, clutter interference reflection is eliminated, the different-degree knocking exciting force can be selected according to actual conditions in experiments, and the invention aims to provide a reference working scheme which is not used as a specific scheme of a specific measurement experiment defined by the invention.
Further, receiving the stress wave at least two signal points on the second side of the foundation pile, comprising: the method comprises the steps that 30-60 signal points are equidistantly arranged along the height direction of a foundation pile, and the distance between two adjacent signal points is 10-40 cm; the method comprises the steps of carrying out a first treatment on the surface of the
And/or the number of the groups of groups,
when the foundation pile is provided with a pier column and a pile body, the end face between the pier column and the pile body is a pile column joint surface, the signal point at the lowest position and the pile column joint surface are at the same height, and the transient excitation point is positioned at the outer side of the pile column joint surface;
when one side of the foundation pile is provided with the capping beam, the lowest signal point and the top of the capping beam are at the same height. In one embodiment of the present invention, considering the way of separating the up-down traveling wave, the present invention further sets the receiving positions of the signal points along the height direction, and when a plurality of signal points receive the corresponding stress waves, a certain time difference is provided, the time difference is determined by the size of the interval, and when the interval is set to be equidistant, it can further ensure that: the backward moving distance of the peak of the head wave is consistent, when a plurality of sections combined with low strain measurement are arranged, stress wave signals received by a plurality of signal points are shown as in-phase axes which move downwards on a section diagram, the slope is negative, the stress wave reflected back after being transmitted by the pile body is also an upward wave, the same principle can be obtained, stress reflected waves at the same pile body position can also form in-phase axes on the low strain section diagram, and the slope is the same as that of the head wave in-phase axes; when one side of the foundation pile is provided with other combined structures, such as a bent cap, when stress waves propagate upwards, the stress waves are reflected by the bent cap, the reflected waves are received by the sensor at the highest position, and then are received by the sensor in sequence from high to low, and the time for the sensor at the higher position to receive the bent cap reflected waves is shorter, so that the reflected wave graph shows that the wave crest of the bent cap reflected waves moves forward. Forming an upward-oriented homophase axis on the low-strain profile, wherein the slope is positive; therefore, a plurality of signal points equidistantly arranged along the height direction realize the coaxial display of a plurality of stress wave measurements or low strain curves on the sectional view, and have obvious in-phase slope difference, and the difference is the basis for separating up-and-down traveling waves.
As shown in fig. 2, preferably, the stress wave is received on a second side of the foundation pile and analyzed to determine structural characteristics of the foundation pile, comprising:
receiving the stress wave at a second side of the foundation pile and converting the stress wave into a response signal;
analog-to-digital converting the response signal into a digital signal, and integrating the digital signal into profile data;
analyzing the profile data by radon transformation, and determining structural characteristics of the foundation pile in combination with external measurement parameter data of the foundation pile, comprising:
the section data comprise a low-strain section picture and a plurality of uplink and downlink phase shafts on the same low-strain section picture, and if the uplink phase shafts are close to the downlink phase shafts with opposite slopes until the downlink phase shafts are intersected, the corresponding depth of the uplink phase shafts is used for representing the structural position of the pile body. In this embodiment, after the stress wave is obtained at the signal point, on the basis of the above-mentioned multiple stress wave signals arranged downward in the same-phase axis direction, because the presence of the up-going and down-going waves is simultaneously displayed on the cross-sectional view, which is unfavorable for the analysis of the foundation pile structure, the invention further considers the nature of radon transformation, and transforms the seismic data in the time domain into τ -p domain (τ is the stress wave double-pass travel time, p is the same-phase axis slope) through linear radon transformation, and because the up-going and down-going waves in the data are approximately linear and have slopes with opposite signs, the data "will be represented as rays with the same slope and passing through the origin in τ -p domain. And then the rays on the left and right sides of the origin are cut off by a simple filtering operator. After filtering, the needed data is reserved, and then the radon inverse transformation is carried out to obtain the corresponding uplink wave profile data.
Further, analyzing the stress wave includes:
according to the stress wave signal when the transient excitation device applies transient excitation force on the foundation pile;
analog-to-digital converting the response signal into a digital signal based on the response signal, and converting the digital signal into sgy data;
carrying out radon transformation on the sgy data to separate out tau-p domain data of each of the uplink and downlink waves;
and converting the up-going and down-going wave tau-p domain data into an up-going and down-going wave section through radon inversion, and analyzing the up-going wave section to obtain the structural characteristics of the foundation pile.
Based on the foundation pile detection method, the invention provides a foundation pile detection system for further implementing the method, comprising the following steps:
excitation generating device: for applying a transient excitation force to a first side of the foundation pile to cause the foundation pile to respond by generating a stress wave signal;
excitation receiving device: and the stress wave signals are used for receiving the transient excitation force at a plurality of signal points on the second side of the foundation pile, and analyzing the structural characteristics of the foundation pile.
Preferably, the excitation receiving device includes: the device comprises a sensor, an analog-to-digital conversion module and a data processing module;
a sensor: the analog-to-digital conversion module is connected with the second side of the foundation pile and used for receiving an electric signal and performing analog-to-digital conversion on the electric signal to obtain a digital signal;
The analog-to-digital conversion module is connected with the data processing module and is used for receiving the digital signals and analyzing the digital signals to obtain the section data, and the defects of the foundation pile and the positions of the defects are obtained according to the section data.
Preferably, the analog-to-digital conversion module includes a sgy module, a radon module, and a display module, where the sgy module is configured to convert the digital signal into sgy data, the radon module is configured to convert the sgy data into profile data, the digital signal is divided into an uplink reflected wave signal profile and a downlink reflected wave signal profile after being converted by the radon of the radon module, and the display module is configured to display the uplink reflected wave signal profile and/or the downlink reflected wave signal profile.
Preferably, the excitation generating means comprises an excitation hammer for applying an excitation force on the foundation pile for obtaining a stress wave signal on the second side of the foundation pile.
Preferably, the foundation pile is provided with a signal point, the excitation measuring device further comprises a sensor and a dynamic side instrument, the sensor is arranged on the signal point, the dynamic side instrument is provided with an analog-to-digital conversion module, and the dynamic side instrument is connected with the data processing module and the display module and is used for storing and displaying profile data after excitation.
Compared with the prior art, the invention has the beneficial effects that:
measuring is carried out on a plurality of signal points, and stress waves brought by exciting force are collected into a plurality of reflected wave signals at a plurality of signal points once by controlling the position distribution of each signal point, so that accidental errors brought by experiments can be avoided;
the detection method or the detection system is selected to excite on the pier column or the tie beam, has lower requirement on the working surface, and is better suitable for detecting the existing or service foundation piles;
by converting stress wave data among a plurality of signals into profile data, the rule of reflected wave signals can be intuitively and clearly observed, or the defect position of the foundation pile can be directly obtained;
separating up-down traveling waves based on Radon transformation, and eliminating down-traveling wave signal interference caused by an upper structure (a capping beam, a tie beam, a pier column and the like) to the greatest extent; meanwhile, the uplink wave signal is reserved, and the reflected wave signal analysis is performed more directly.
Example 2
Based on the foundation pile detection method and system of embodiment 1, embodiment 2 provides a more specific foundation pile and defect detection example; the response signals are received by a plurality of sensors and displayed in a cross-sectional view mode, namely, the reflected wave curve is clockwise rotated by 90 degrees, and the peak part is filled with black, so that a low-strain cross-sectional view is obtained. Fig. 3 is a cross-sectional view of a 40-channel low-strain curve, and it can be seen that the reflection wave phase axis clearly shows the pile top and pile bottom positions, and the foundation for evaluating the foundation pile is not dependent on a single curve, but is analyzed based on the common characteristics of multiple curves, so that misjudgment caused by interference except the foundation pile response can be reduced.
Based on the foundation pile detection method or detection system of embodiment 1, referring to fig. 3, fig. 3 is an exemplary excited original wave-section record, for which it can be seen that it has a significant trend distribution, in one straight line at the topmost side, it is significant reflection impedance with a downward trend and a negative slope, according to the content of embodiment 1, it is an upstream wave section data content, in another straight line below the straight line, it is significant reflection impedance with an upward trend and a positive slope, and similarly it is presumed that it is downstream wave section data; the invention aims to acquire corresponding uplink wave section data;
therefore, when the simulated complete foundation pile is excited, the existing foundation pile model common in actual engineering is built, and finite element numerical simulation analysis is carried out. And an explicit dynamic analysis module of Ansys software is adopted, the sizes of the model piles are shown in table 1, and the model piles are schematically shown in fig. 4, and forward modeling is respectively carried out on the situation of the existence of pile body defects.
TABLE 1 model pile size information (Unit: m)
| Pile type | Pile length// pile diameter | Defect location | Pier column size | Size of capping beam |
| Defect-free friction pile | 23/1.4 | \ | 8*φ1.3 | 12*1.4*1.4 |
| Defect friction pile | 23/1.4 | 15.5-16.5m below the pile top | 8*φ1.3 | 3.8*1.4*1.4 |
Specifically, the foundation pile structure includes: the pier diameter is smaller than that of the bottom pile, the pier is arranged on the bottom pile, the pier is loaded with the capping beam, a shock excitation surface is arranged between the pier and the bottom pile, the bottom pile of the comparison example is provided with a defect which is a defective friction pile, the defect is smaller than the normal diameter of a pile body, the defect is a defect which is unfavorable for diameter shrinkage, the first sensor is positioned at a position which is aligned with the shock excitation point and has an included angle of 90 degrees, 40 sensors are distributed along the height direction of the pier, the distance between the adjacent sensors is 0.2m, a shock excitation force is applied on the shock excitation surface once, a stress wave signal is obtained through a dynamic side instrument connected with the sensors,
Specifically, the foundation pile comprises a pile body, a pier column and a pile column joint surface between the pile body and the pier column, wherein the spatial relation of excitation is that an excitation point is positioned at the position of the pile column joint surface at the top end of the foundation pile, and a signal receiving point is arranged on the pier column, so that the position of the excitation point is not higher than the signal receiving point, namely, when a stress wave is excited, only the stress wave transmitted to the pier column is received. While the stress wave propagating in the pier stud includes two types: 1. the pile body and the pile bottom reflect the upward stress wave; 2. the pier stud and the capping beam reflect the reflected downward stress wave. For further analysis, the top-down reception of the signal reception points was sequential reception and the top-down reception of the signal reception points was reverse reception. Therefore, after the low strain profile is formed by the program conversion, the upstream wave is the homophase axis with a negative slope, and the downstream wave is the homophase axis with a positive slope.
Taking fig. 8 as an example, the two waves propagating in the pier stud have a sequence of propagation, and first discussing the characteristic of propagation of the head wave: after the stress wave is excited, a part of energy is upwards transmitted in the pier column, and is sequentially received by the sensor along with the increase of the transmission distance, a first negative slope reflection wave homophase axis is formed on the low-strain section view, the corresponding depth is 0m, the stress wave continues to upwards transmit to the bent cap until being reflected back to become a descending wave, the descending wave downwards transmits in the pier column and is reversely received by the sensor, and a first positive slope reflection wave homophase axis is formed on the low-strain section view, and the corresponding depth is 9.5m;
Pile body structure reflected wave (including pile body defect reflected wave and pile bottom reflected wave, only pile bottom reflection is discussed this time, pile body defect reflection is the same) propagation characteristics: after the stress wave is excited, a part of energy downwards propagates at the pile body, when the energy is reflected at the pile bottom, the stress wave starts to upwards propagate until the stress wave propagates to the pier column and is sequentially received by the sensor, a second negative slope reflected wave homophase axis is formed on the low-strain section view, the corresponding depth of the second negative slope reflected wave homophase axis is 15.5m, the stress wave continues to upwards propagate to the bent cap until the stress wave is reflected back to become a downlink wave, and the downlink wave downwards propagates at the pier column and is reversely received by the sensor, and a second positive slope reflected wave homophase axis is formed on the low-strain section view.
Therefore, when the stress wave propagates upward in the pier stud, the upward wave signal is sequentially received, and the stress wave must continue to propagate upward, reflect back through the roof beam top, propagate downward, and then be received by the sensor in reverse order. The signals received by the sensors at the two times are increased along with the increase of the sensor layout height, the time of sequential receiving is increased, the time of reverse receiving is reduced, and the signals are continuously close to the same phase axis on the low-strain profile. Meanwhile, the phenomenon only occurs when the pier column has uplink wave transmission, which provides necessary basis for directly analyzing the integrity of the pile body through the low-strain section view.
The specific analysis is as follows:
the original profile obtained for the complete foundation pile model is shown in fig. 5, analyzed by further radon transformation:
if there are n stress wave curves, the linear Radon transform is forward transformed into:
d (t, x) represents seismic data, x is offset, and t is a double travel time; u (τ, q) is Radon domain data, τ is the time intercept, and q represents the curvature of the curve.
After Radon transformation, m data are shared in a tau-p domain, a graph of the Radon transformation domain is shown in fig. 6, and the seismic section is represented as rays passing through an origin in the tau-p domain formed by the Radon transformation, namely: the same-phase axis of the same slope will map to a region, even a point, in the τ -p domain.
Cutting rays on the left and right of the origin by a simple filtering operator;
the filtering algorithm is as follows:
wherein lambda is p; the corresponding reflection wave phase axis can be reserved or filtered through filtering.
Its inverse, corresponding to the filtered data field, is:
as shown in fig. 7, the cross-sectional graph after radon separation has a significant reflection impedance at the depth of 23m, and in the pile-bottom structure with the excitation surface facing downwards, there is just one reflection impedance at the depth of 23m, which indicates that the pile-bottom structure has no defect;
Correspondingly, FIG. 8 shows an original cross-sectional view of a defective foundation pile, FIG. 9 shows a radon transform domain view of the defective foundation pile, and FIG. 10 shows a downstream cross-sectional view of the defective foundation pile after being filtered and inversely transformed by a filtering algorithm; FIG. 11 shows an upstream cross-sectional view of a defective foundation pile, comparing the cross-sectional view of the complete foundation pile with the radon transform domain map, it can be seen that:
as can be seen from fig. 5 and 8, the phase axis of the reflected wave has a distinct positive and negative slope, and the absolute value of the slope of the up-down traveling wave is the same. The defect wave is covered by the downgoing wave in the area with smaller track number, and the obvious reflection wave phase axis exists in the area with larger track number, so that the limitation of single-track low-strain detection is fully reflected, namely the foundation pile structure reflection can not be recognized in a disadvantageous pick-up system. The reflected wave on the cross section is transformed by Radon and is represented in the form of energy clusters in the τ -p domain, as shown in fig. 6 and 9. Fig. 12 and 10 show the down-going wave cross-section of the complete foundation pile and the defective foundation pile, which are basically consistent, and can accurately identify the reflection of the bottom and the top of the capping beam, thereby confirming the effectiveness and accuracy of the method for identifying and separating the up-going wave and the down-going wave. The reflected wave phase axis of the pile bottom in FIG. 11 has stronger energy at 15.5m, has obvious reverse signals at 16.5m, is expressed as a diameter reduction defect with the length of 1m, accords with the defect design of a model, has a 'split' at a small track number, and is a phenomenon that the defect wave reflected from a capping beam is overlapped with the reflected wave at the pile bottom. Therefore, the radon detection method of the invention achieves ideal effect in forward modeling, and can clearly distinguish the defect position of the pile body and the position of the pile bottom.
Example 3
Based on example 2, example 3 further simulates a second type of foundation pile defect, namely, a broken pile, i.e., on the basis of a complete foundation pile, a fault structure is set at a depth of 20m of the foundation pile,
the results of the test performed using the same method are as follows:
correspondingly, fig. 13 shows an original cross-section of a broken pile, fig. 14 shows a radon transform domain of the broken pile, and fig. 15 shows a downstream cross-section of the broken pile after filtering and inverse transformation by a filtering algorithm; FIG. 16 shows an upstream-traveling wave profile of a defective foundation pile, relative to a profile of a complete foundation pile and a radon transform domain map:
comparing the same original wave patterns 5 and 13, it can be found that the same original wave pattern 13 has an obvious opposite reflection axis at the depth of 20m, namely, represents that the corresponding stress wave has fault or reflection transmission phenomenon at the depth of 20m, compared with the original wave pattern 5, therefore, in a specific experiment, if the depth corresponding to the same phase reflection axis is found to be obviously smaller than the known construction parameter, the defect that a broken pile is arranged at the depth of 20m and 3m from the lowest point can be found according to the original construction parameter, namely, the complete foundation pile model parameter, and the difference of the uplink wave profile data of the comparison patterns 15 and 10 is also smaller, and the defect analysis result is the same as that of the defect analysis result, particularly the uplink wave profile of fig. 16, which has an obvious same phase reflection axis at the depth of 20m, namely, fault occurs.
Example 4
Based on example 2, the invention further simulates a simulation detection result of an advantageous defect, and a layer of expanding structure is added on the foundation pile with the height of 15-16.5 m, which is named as an expanding model.
As a result, as shown in fig. 17 and 18, fig. 17 is an original sectional view, and as shown in fig. 18, the same detection analysis method is used to compare the upstream wave sectional view of the complete foundation pile, and it can be found that there is one more in-phase reflection axis between 15.5 and 16.5m, that is, the position structure has an obvious protruding structure under the condition of complete foundation pile, so that the stress wave response is not affected, and the resonance impedance of the protruding structure at the position is increased.
It should be understood that the foregoing examples of the present invention are merely illustrative of the present invention and are not intended to limit the present invention to the specific embodiments thereof. Any modification, equivalent replacement, improvement, etc. that comes within the spirit and principle of the claims of the present invention should be included in the protection scope of the claims of the present invention.
Claims (5)
1. A foundation pile detection method for detecting defects of a foundation pile in service, comprising:
Setting an excitation point/excitation surface on a first side of a foundation pile;
applying a transient excitation force to the excitation point/surface to generate a stress wave and transmitting the stress wave to a second side of the foundation pile;
receiving the stress waves at least two signal points on a second side of the foundation pile and analyzing all the stress waves to derive structural characteristics of the foundation pile and to determine defects of the foundation pile;
receiving the stress wave on a second side of the foundation pile and analyzing the stress wave to determine structural characteristics of the foundation pile, comprising:
receiving the stress wave at the second side of the foundation pile, performing analog-to-digital conversion and recording a speed signal of the stress wave;
combining the speed signals recorded by all the signal receiving points into matrix arrays, and integrating the matrix arrays into low-strain profile data through program conversion;
determining structural characteristics of the foundation pile by analyzing the low strain profile data, comprising:
the section data comprise a low-strain section chart and a plurality of uplink and downlink in-phase axes on the same low-strain section chart, and if the uplink in-phase axes have downlink in-phase axes with opposite slopes and are close to each other until the downlink in-phase axes are intersected, the depth corresponding to the uplink in-phase axes is used for representing the defect position of the pile body;
The low-strain section data are subjected to radon transformation to separate an uplink wave section chart, and the defect characteristics of the pile body or the position of the pile bottom are analyzed according to a reflection wave phase axis in the uplink wave section chart;
converting low-strain section data in a time domain into a tau-p domain through linear radon transformation, cutting rays on the left and right sides of an original point through a filtering operator, retaining needed data after filtering, obtaining low-strain section data only with upstream waves through inverse transformation, obtaining corresponding upstream wave section data through radon inverse transformation, reflecting different pile body defect positions corresponding to upstream wave reflection phase shafts in each upstream wave section graph, and obtaining pile body defect characteristics by combining construction parameter comparison before a pile body.
2. A foundation pile detection method according to claim 1, wherein setting the excitation point/excitation surface comprises:
when a horizontal plane is arranged in the direction perpendicular to the height direction of the foundation pile, setting the horizontal plane as an excitation surface, and setting the drop point of the excitation force on the excitation surface as a transient excitation point;
when the foundation pile structure does not have the horizontal plane, a measuring height is positioned, an excitation groove with the bottom being flush with the measuring height is formed in the measuring height position of the foundation pile, the bottom surface of the excitation groove is set to be an excitation surface, and the drop point of the excitation force on the excitation surface is set to be a transient excitation point.
3. A foundation pile detection method according to claim 1, wherein setting a transient excitation point/surface on a first side of the foundation pile comprises:
the height of the transient excitation point/excitation surface on the first side of the foundation pile is flush with the height of the signal receiving point with the lowest height on the second side of the foundation pile; and/or, enabling the direction of the transient exciting force to be perpendicular to the height direction of the foundation pile and vertically downwards.
4. A foundation pile detection method according to claim 1, wherein the stress wave is received on a second side of the foundation pile and the stress wave is analyzed to determine structural characteristics of the foundation pile, comprising:
knocking the foundation pile at a first side of the foundation pile at a preset average speed and/or a preset excitation force so as to enable the foundation pile to generate stress waves and transmit the stress waves to a second side of the foundation pile, or knocking the same position of the foundation pile at different average speeds and/or different excitation forces each time so as to enable the foundation pile to generate stress waves and transmit the stress waves to the second side of the foundation pile; and/or; the foundation pile is hit each time at a different location on the first side of the foundation pile, so that the foundation pile generates a stress wave and transmits it to the second side of the foundation pile.
5. A foundation pile detection method according to claim 1, wherein receiving the stress wave at least two signal receiving points on the second side of the foundation pile comprises:
And 30-60 signal points are equidistantly arranged along the height direction of the foundation pile, and the distance between two adjacent signal points is 10-30 cm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210938356.4A CN115404920B (en) | 2022-08-05 | 2022-08-05 | Foundation pile detection method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210938356.4A CN115404920B (en) | 2022-08-05 | 2022-08-05 | Foundation pile detection method and system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115404920A CN115404920A (en) | 2022-11-29 |
| CN115404920B true CN115404920B (en) | 2024-03-12 |
Family
ID=84158847
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210938356.4A Active CN115404920B (en) | 2022-08-05 | 2022-08-05 | Foundation pile detection method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115404920B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117493858B (en) * | 2023-12-29 | 2024-03-26 | 湖北神龙工程测试技术有限公司 | Foundation pile integrity recognition method based on artificial intelligence |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008185426A (en) * | 2007-01-29 | 2008-08-14 | Takenaka Komuten Co Ltd | Integrity evaluation support device, method, and program of concrete pile |
| CN103669428A (en) * | 2013-12-04 | 2014-03-26 | 中交四航工程研究院有限公司 | Integrity detection system with bearing platform foundation pile |
| CN109469114A (en) * | 2018-11-23 | 2019-03-15 | 中国建筑科学研究院有限公司 | A kind of method for the existing foundation pile integrity of low strain integrity testing that can eliminate superstructure influence |
| CN210395465U (en) * | 2019-04-18 | 2020-04-24 | 广东天信电力工程检测有限公司 | Side surface excitation structure for detecting integrity of foundation pile by double-speed method and detection device |
-
2022
- 2022-08-05 CN CN202210938356.4A patent/CN115404920B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008185426A (en) * | 2007-01-29 | 2008-08-14 | Takenaka Komuten Co Ltd | Integrity evaluation support device, method, and program of concrete pile |
| CN103669428A (en) * | 2013-12-04 | 2014-03-26 | 中交四航工程研究院有限公司 | Integrity detection system with bearing platform foundation pile |
| CN109469114A (en) * | 2018-11-23 | 2019-03-15 | 中国建筑科学研究院有限公司 | A kind of method for the existing foundation pile integrity of low strain integrity testing that can eliminate superstructure influence |
| CN210395465U (en) * | 2019-04-18 | 2020-04-24 | 广东天信电力工程检测有限公司 | Side surface excitation structure for detecting integrity of foundation pile by double-speed method and detection device |
Non-Patent Citations (1)
| Title |
|---|
| "Radon变换在VSP波场分离中的应用";李远钦等;《石油地球物理勘探》;第25卷(第6期);653-661、761 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115404920A (en) | 2022-11-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102422154B (en) | System, device for structural damage detection and method for structural damage detection | |
| CN102680575B (en) | A kind of impact mapping method of Complicate soil medium and system | |
| CN102877490B (en) | Method for detecting quality of large-diameter tubular pile at low strain | |
| CN104007176B (en) | Full-wave field detection system and method of complex geotechnical engineering medium | |
| CN103088849B (en) | A kind of servicing bridges foundation pile stress wave echo lossless detection method | |
| CN103669428B (en) | With the integrity detection system of cushion cap foundation pile | |
| Liao et al. | Numerical simulation and experimental study of parallel seismic test for piles | |
| CN105973619A (en) | Bridge local damage identification method based on influence line under structure health monitoring system | |
| CN103018337A (en) | Surface wave-based nondestructive testing method and system for internal concrete state | |
| CN103774700B (en) | Method for detecting integrity of high flat bed pile under existing building through overtone response function method | |
| CN102016566A (en) | Ultrasonic flaw detection method and device | |
| CN115404920B (en) | Foundation pile detection method and system | |
| CN110361453B (en) | Array type ectopic receiving ultrasonic synthetic aperture focusing method based on nondestructive testing | |
| Huang et al. | Experimental study for the evaluation of stress wave approaches on a group pile foundation | |
| CN112663689B (en) | Multi-measuring-point low-strain detection method for high-bearing-platform pile foundation | |
| CN103774701B (en) | The method of Vertical spots integrality under virtual isolation single pile method detection existing structure thing | |
| CN108797662A (en) | Pile foundation length non-destructive test method and device under column | |
| CN103630605A (en) | Method for detecting grouting quality of prestressed anchor cable pipeline | |
| CN104764804A (en) | Ultrasonic Lamb wave local circulation scanning probability reconstruction tomography method | |
| Zimatore et al. | The remarkable coherence between two Italian far away recording stations points to a role of acoustic emissions from crustal rocks for earthquake analysis | |
| CN103412056A (en) | Acoustic emission wave mode separation method based on double sensors for plate-like structure | |
| Che et al. | An elastic-wave-based full-wavefield imaging method for investigating defects in a high-speed railway under-track structure | |
| CN219219128U (en) | Foundation pile detection device | |
| CN108487336A (en) | A kind of geotechnical engineering pile foundation quality detection method and detection device | |
| CN108560617A (en) | A kind of pile defect detection method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |