Disclosure of Invention
The invention aims to provide a bridge engineering foundation pile detection method to solve the problems in the background technology.
In order to achieve the purpose, the invention provides the following technical scheme: a bridge engineering foundation pile detection method comprises the following steps:
s1, detecting defects of a foundation pile;
s2, establishing a foundation pile low-strain detection system;
s3, carrying out low strain detection on the foundation pile;
s4, establishing a length detection system of the foundation pile reinforcement cage;
and S5, detecting the length of the foundation pile reinforcement cage.
Preferably, the method for detecting a foundation pile defect in S1 specifically includes the following steps:
s11, cleaning and leveling the detection surface of the foundation pile, removing a surface loose layer, laitance, oil dirt, a coating, a honeycomb surface and a pitted surface, removing the loose layer and impurities by using a grinding wheel, and removing residual powder and debris;
s12, taking three sounding pipes, penetrating the three sounding pipes into the foundation pile, and numbering and recording the three sounding pipes;
s13, measuring the inner distances of the outer walls of the three sound measuring tubes, wherein the measuring result is accurate to mm, measuring the exposed lengths of the three sound measuring tubes, the measuring result is accurate to mm, measuring the outer diameters and the inner diameters of the three sound measuring tubes, the measuring result is accurate to mm, and then measuring the diameters of the sound measuring tubes by using a transducer;
s14, setting project names, pile numbers and length parameters of the piles on the host, and then setting the number of the sounding pipes and data values measured by the sounding pipes on the host;
s15, filling clear water into the three sounding pipes, and testing the smoothness degree of the sounding pipes;
s16, placing a tripod, installing a constant-speed lifting device, adjusting the direction of the tripod, aligning the outlet direction of the constant-speed lifting device to the tested foundation pile, installing a pipe orifice pulley, placing the transducer, and centering the transducer as much as possible.
Preferably, the foundation pile low strain detection system established in S2 includes: the device comprises a detection instrument, a foundation pile to be detected, a small hammer, a striking point, a stress wave sensor and a graduated scale.
Preferably, the method for detecting low strain of foundation pile in S3 specifically includes the following steps:
s31, processing the pile top of the foundation pile to be detected, wherein the pile top surface is smooth and compact and is vertical to the pile axis, and polishing a plurality of striking points and mounting points of corresponding stress wave sensors to be smooth;
s32, before the detection instrument is started, connecting a four-core plug of the stress wave sensor to a four-core socket of the detection instrument, and correspondingly connecting red points on the four-core plug of the stress wave sensor with red point marks on the four-core socket of the detection instrument;
s33, mounting the bottom surfaces of the stress wave sensors on the top surface of the pile of the bridge foundation pile to be detected through grease bonding, and enabling each stress wave sensor to be located at the position, on the connecting line of the corresponding impact point and the pile center, of equal distance from the pile edge;
s34, opening a detection instrument, entering a main interface, and setting various acquisition parameters;
s35, after parameter setting is finished, returning to a low-strain data acquisition main interface, clicking an operation command area to perform continuous acquisition, and enabling a waveform display area to have a character of waiting for drop hammer;
s36, enabling the graduated scale to be perpendicular to the pile top surface of the foundation pile to be detected and to be placed on one side of a striking point, enabling the small hammer to freely fall from the same height, and enabling the small hammer to strike the striking point;
and S37, after the impact, the detection wave band displays the wave band on the interface of the detection instrument through the stress wave sensor.
Preferably, the parameter setting in S34 includes pile type, pile number, wave speed, concrete level, trigger level, sampling interval, sampling number, project name, storage path, low-pass filtering, high-pass filtering, exponential amplification position, point-source distance, real-time monitoring setting, delay point number, acquisition selection, test method, trigger channel, sensor type, sensitivity coefficient, integral state, and adjustment system parameter.
Preferably, the pile reinforcement cage length detecting system established in S4 includes a terahertz transceiver, a terahertz detector, a computer, a first optical mechanism, and a second optical mechanism.
Preferably, the terahertz transceiver comprises a terahertz transmitter, a terahertz detector, a current amplifier, a lock-in amplifier, a data acquisition card, a femtosecond laser and a one-to-two optical fiber coupler.
Preferably, the first optical mechanism and the second optical mechanism each include an off-axis parabolic mirror and a terahertz mirror.
Preferably, the method for detecting the length of the pile cage in S5 specifically includes the following steps:
s51, enabling the terahertz transmitting and receiving device to scan the foundation pile along the length direction of the foundation pile;
s52, transmitting the terahertz waves emitted by the terahertz transmitter to a foundation pile to be detected through a first optical mechanism;
s53, transmitting the terahertz waves reflected by the foundation pile to a terahertz detector through a second optical mechanism, converting the terahertz waves into electric signals by the terahertz detector, and transmitting the electric signals to a terahertz detection device;
s54, collecting an electric signal output by the terahertz detector by the terahertz detection device and uploading the electric signal to a computer;
s55, generating a terahertz image by the computer according to the electric signal uploaded by the terahertz detection device;
s56, specific positions of the reinforcement cages in the foundation piles are determined by observing bright and dark areas in the terahertz images, and then the actual lengths of the reinforcement cages in the foundation piles are calculated.
Compared with the prior art, the invention has the beneficial effects that: the method and the device have the advantages that firstly, the defects of the foundation pile are detected, the defects can be conveniently analyzed, the condition of the defects can be conveniently obtained, the detection on wave bands during the low-strain detection of the foundation pile is facilitated by establishing the foundation pile low-strain detection system, and in addition, the actual length of the reinforcement cage in the bridge foundation pile can be conveniently calculated by establishing the foundation pile reinforcement cage length detection system and detecting the length of the foundation pile reinforcement cage.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
Referring to fig. 1, the present invention provides a technical solution: a bridge engineering foundation pile detection method comprises the following steps:
s1, detecting defects of a foundation pile;
s2, establishing a foundation pile low-strain detection system;
s3, carrying out low strain detection on the foundation pile;
s4, establishing a length detection system of the foundation pile reinforcement cage;
and S5, detecting the length of the foundation pile reinforcement cage.
In this embodiment, preferably, the method for detecting a foundation pile defect in S1 specifically includes the following steps:
s11, cleaning and leveling the detection surface of the foundation pile, removing a surface loose layer, laitance, oil dirt, a coating, a honeycomb surface and a pitted surface, removing the loose layer and impurities by using a grinding wheel, and removing residual powder and debris;
s12, taking three sounding pipes, penetrating the three sounding pipes into the foundation pile, and numbering and recording the three sounding pipes;
s13, measuring the inner distances of the outer walls of the three sound measuring tubes, wherein the measuring result is accurate to mm, measuring the exposed lengths of the three sound measuring tubes, the measuring result is accurate to mm, measuring the outer diameters and the inner diameters of the three sound measuring tubes, the measuring result is accurate to mm, and then measuring the diameters of the sound measuring tubes by using a transducer;
s14, setting project names, pile numbers and length parameters of the piles on the host, and then setting the number of the sounding pipes and data values measured by the sounding pipes on the host;
s15, filling clear water into the three sounding pipes, and testing the smoothness degree of the sounding pipes;
s16, placing a tripod, installing a constant-speed lifting device, adjusting the direction of the tripod, aligning the outlet direction of the constant-speed lifting device to the tested foundation pile, installing a pipe orifice pulley, placing an energy converter, and centering the energy converter as much as possible;
by cleaning and flattening the detection surface of the bridge foundation pile, the detection wave band data influenced by soil and stone impurities, surface loose layers, pitted surfaces, honeycombs and the like can be better prevented, and the detection accuracy is improved; promote the cable through adopting at the uniform velocity hoisting device for the transducer can carry out the rising at the uniform velocity in the inside of sounding pipe, is convenient for carry out short-term test to bridge foundation pile, improves and detects accuracy and efficiency.
In this embodiment, it is preferable that the foundation pile low strain detection system established in S2 includes: the device comprises a detection instrument, a foundation pile to be detected, a small hammer, a striking point, a stress wave sensor and a graduated scale.
In this embodiment, preferably, the method for detecting low strain of the foundation pile in S3 specifically includes the following steps:
s31, processing the pile top of the foundation pile to be detected, wherein the pile top surface is smooth and compact and is vertical to the pile axis, and polishing a plurality of striking points and mounting points of corresponding stress wave sensors to be smooth;
s32, before the detection instrument is started, connecting a four-core plug of the stress wave sensor to a four-core socket of the detection instrument, and correspondingly connecting red points on the four-core plug of the stress wave sensor with red point marks on the four-core socket of the detection instrument;
s33, mounting the bottom surfaces of the stress wave sensors on the top surface of the pile of the bridge foundation pile to be detected through grease bonding, and enabling each stress wave sensor to be located at the position, on the connecting line of the corresponding impact point and the pile center, of equal distance from the pile edge;
s34, opening a detection instrument, entering a main interface, and setting various acquisition parameters;
s35, after parameter setting is finished, returning to a low-strain data acquisition main interface, clicking an operation command area to perform continuous acquisition, and enabling a waveform display area to have a character of waiting for drop hammer;
s36, enabling the graduated scale to be perpendicular to the pile top surface of the foundation pile to be detected and to be placed on one side of a striking point, enabling the small hammer to freely fall from the same height, and enabling the small hammer to strike the striking point;
s37, after the impact, the detection wave band displays the wave band on the interface of the detection instrument through a stress wave sensor;
the graduated scale is perpendicular to the pile top surface of the bridge foundation pile to be detected, the graduated scale is located on one side of a striking point, the small hammer is moved to the same height position, and is loosened to enable the small hammer to freely fall, so that the small hammer can strike the striking point at the same height position in use, and the detection accuracy of a wave band is effectively improved; through adopting the butter to bond stress wave sensor at the pile bolck face of waiting to detect bridge foundation pile, in the use, can be better fix stress wave sensor's position for stress wave sensor can not break away from not hard up when using, the effectual wave band that has improved detects the accuracy.
In this embodiment, preferably, the parameter setting in S34 includes a pile type, a pile number, a wave speed, a concrete level, a trigger level, a sampling interval, a sampling number, a project name, a storage path, low-pass filtering, high-pass filtering, exponential amplification, an exponential amplification position, a point-source distance, real-time monitoring setting, a delay point number, acquisition selection, a test method, a trigger channel, a sensor type, a sensitivity coefficient, an integration state, and an adjustment system parameter.
In this embodiment, preferably, the length detecting system for the foundation pile cage established in S4 includes a terahertz transceiver, a terahertz detector, a computer, a first optical mechanism, and a second optical mechanism.
In this embodiment, preferably, the terahertz transceiver includes a terahertz transmitter, a terahertz detector, a current amplifier, a lock-in amplifier, a data acquisition card, a femtosecond laser, and a one-to-two fiber coupler.
In this embodiment, preferably, the first optical mechanism and the second optical mechanism each include an off-axis parabolic mirror and a terahertz mirror.
In this embodiment, preferably, the method for detecting the length of the pile cage in S5 specifically includes the following steps:
s51, enabling the terahertz transmitting and receiving device to scan the foundation pile along the length direction of the foundation pile;
s52, transmitting the terahertz waves emitted by the terahertz transmitter to a foundation pile to be detected through a first optical mechanism;
s53, transmitting the terahertz waves reflected by the foundation pile to a terahertz detector through a second optical mechanism, converting the terahertz waves into electric signals by the terahertz detector, and transmitting the electric signals to a terahertz detection device;
s54, collecting an electric signal output by the terahertz detector by the terahertz detection device and uploading the electric signal to a computer;
s55, generating a terahertz image by the computer according to the electric signal uploaded by the terahertz detection device;
s56, specific positions of the reinforcement cages in the foundation piles are determined by observing bright and dark areas in the terahertz images, and then the actual lengths of the reinforcement cages in the foundation piles are calculated.
Example 2
The difference from example 1 is that: the method for detecting the foundation pile defect in the step S1 specifically includes the following steps:
s11, knocking the upper part of the foundation pile by using a hammer, and collecting reflected wave data through a sensor arranged on the upper part of the foundation pile;
s12, substituting the data collected in the step S11 into the following formula for analysis, establishing a oscillogram, and analyzing and comparing the oscillograms;
in the formula: vibration displacement of V mass point; the distance from the vibration of the X mass point to the vibration source; t time of vibration of mass point; n damping coefficient; the sectional area of the pile A; vPVelocity V of longitudinal wave propagating in pilePE/ρ; mass density of rho piles;
when the pile top applies instantaneous external force F (t), only the down-going wave exists in the pile, the wave is reflected on different wave impedance surfaces, and the time of the stress wave traveling in the pile body and the longitudinal wave velocity of the stress wave to the piles with different structures can be deduced from the formula;
s13, when the pile body has defects, each interface reflects to make a curve complex, when a large deviation occurs between the amplitude and the amplitude of the previous moment in the oscillogram delta t, the delta t is the defect reflection time, and the distance between the position where the problem occurs and the pile top is calculated by substituting the following formula;
L'=VPΔt/2
in the formula: vPAverage value of longitudinal wave speeds of a plurality of measured qualified pile bodies in the same construction site;
distance between the L' defect position and the pile top;
s14, starting a nondestructive testing device according to the distance L' calculated in the S13, moving the nondestructive testing device to the problem area, carrying out sound wave CT on the area with the problem, and collecting data;
s15, establishing an ultrasonic CT model of the detected region according to the data obtained by measurement in S14;
and S16, carrying out quantitative analysis on the defect part according to the ultrasonic CT model established in the S15 to obtain the shape, the size and the position of the defect part.
The working principle and the advantages of the invention are as follows: the method and the device have the advantages that firstly, the defects of the foundation pile are detected, the defects can be conveniently analyzed, the condition of the defects can be conveniently obtained, the detection on wave bands during the low-strain detection of the foundation pile is facilitated by establishing the foundation pile low-strain detection system, and in addition, the actual length of the reinforcement cage in the bridge foundation pile can be conveniently calculated by establishing the foundation pile reinforcement cage length detection system and detecting the length of the foundation pile reinforcement cage.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.