CN112668073B - Method for quickly analyzing integrity coefficient of foundation pile by introducing pile-soil interaction - Google Patents
Method for quickly analyzing integrity coefficient of foundation pile by introducing pile-soil interaction Download PDFInfo
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Abstract
The invention discloses a method for quickly analyzing the integrity coefficient of a foundation pile by introducing pile-soil interaction, and relates to the field of testing of the structural integrity of the foundation pile. The method comprises the following steps: step 1, obtaining a particle vibration speed response curve of the pile top of a detected foundation pile; step 2, determining the position of the reflecting surface from the top surface of the pile according to the time difference corresponding to the peak value of the particle vibration speed of the first wave and the first reflected wave of the pile body in the particle vibration speed response curve; step 3, analyzing the integrity coefficient of the reflecting surface foundation pile without considering the interaction influence of pile and soil through the ratio of the mass point vibration velocity peak value of the first reflected wave of the pile body to the head wave mass point vibration velocity peak value; and 4, introducing the influence of pile-soil interaction on wave propagation by the pile soil surrounding property parameters, and correcting the integrity coefficient of the reflecting surface foundation pile. The method can solve the problem that the analysis method of the integrity coefficient of the reflecting surface foundation pile based on the amplitude ratio does not consider the interaction influence of the pile and the soil.
Description
Technical Field
The invention relates to the field of testing of structural integrity of foundation piles, in particular to a method for quickly analyzing an integrity coefficient of a foundation pile by introducing pile-soil interaction.
Background
The foundation pile is widely used for engineering foundations of urban buildings, bridges, wharfs and the like, the quality problems of aggregate and concrete separation, mud inclusion, hole shrinkage, cracks, fracture and the like often occur in the construction process of the foundation pile, and the integrity detection of the foundation pile is very important to the engineering quality and safety. These quality problems can cause the wave impedance of the section of the pile body to change relatively, the relative change of the wave impedance of the section of the pile body is often detected by adopting a knocking echo method, the method is knocked on the pile top of a detected foundation pile, the excited wave propagates downwards along the pile body, and when the wave impedance of the pile body changes relatively, the wave is reflected at a wave impedance change interface. A particle vibration speed response test curve is obtained by using an acceleration sensor at the pile top, and the position, the range and the degree of the wave impedance change are determined by analyzing the test curve, wherein the following two methods are commonly adopted at present:
the method comprises the following steps: first, the relative change of the wave impedance of the reflecting surface, namely the increase or decrease change of the pile body wave impedance below the reflecting surface relative to above the reflecting surface is judged according to the phase relation of the vibration speeds of the reflected wave and the mass point of the head wave. Then, the average wave velocity is determined according to the design length of the detected foundation pile and the travel time of the reflected wave at the bottom of the pile, and then the position of the reflecting surface is determined according to the travel time of the reflected wave and the average wave velocity. Under the condition of no influence of pile-soil interaction, a relation between the integrity coefficient of the foundation pile on the reflecting surface and the vibration speed peak value ratio of the reflected wave and the primary wave mass point is given by a one-dimensional fluctuation theory, and by utilizing the relation, the integrity coefficient of the foundation pile can be directly calculated by the vibration speed peak value ratio of the reflected wave and the primary wave mass point in a test curve. However, due to the influence of pile-soil interaction, waves are attenuated in the downward propagation and reflection processes, and under the condition that the reflection surface has the same pile integrity coefficient, the peak value of the reflected wave under the pile-soil interaction condition is smaller than that under the condition that no pile-soil interaction exists, so that the pile integrity coefficient can deviate from an actual value by directly calculating the ratio of the reflected wave to the peak value of the primary wave. For the situation that the wave impedance is relatively reduced, the calculated value of the integrity coefficient of the foundation pile is larger than the actual value; for the case that the wave impedance is increased, the calculated value of the pile integrity factor is lower than the actual value. Therefore, before using the relation between the pile integrity factor and the ratio of the reflected wave to the vibration velocity peak of the head wave particle under the condition of no pile-soil interaction, the reflected wave peak must be corrected so as to consider the attenuation of the wave under the pile-soil interaction.
The method 2 comprises the following steps: in order to introduce the influence of pile-soil interaction on wave propagation and carry out fitting analysis on a mass point vibration velocity response test curve, however, the test curve is susceptible to the influence of factors such as a pile top three-dimensional wave field, sensor frequency characteristics and hammering, some responses of the test curve do not correspond to pile body wave impedance reflected waves, and during fitting analysis, an analyst needs to have higher professional knowledge and carry out filtering, correction and other processing on the test curve so as to reduce the influence of the factors on the test curve, otherwise, changes of the test curve related to the influence factors can be mistakenly taken as pile body reflected wave responses for fitting, so that the accuracy of an analysis result is reduced, and even errors are caused.
Aiming at the problems that the analysis of the pile integrity coefficient by the ratio of the reflected wave of the test curve to the peak value of the primary wave does not consider the interaction influence of pile and soil and the waveform fitting analysis method is easy to take the abnormal error of the response curve caused by the interference of other factors as the response fitting of effective reflected wave, the invention aims to provide a method for quickly analyzing the pile integrity coefficient by introducing the interaction influence of pile and soil, modifying the vibration speed attenuation of the mass point of the reflected wave and obtaining the ratio of the reflected wave to the peak value of the primary wave after modification, thereby improving the analysis precision of the pile integrity coefficient.
Disclosure of Invention
The invention aims to solve the technical problem of providing a method for quickly analyzing the integrity coefficient of a foundation pile by introducing pile-soil interaction aiming at the defects of the prior art.
The technical scheme for solving the technical problems is as follows: a method for quickly analyzing the integrity coefficient of a foundation pile by introducing pile-soil interaction comprises the following steps:
step 5, presetting pile section wave impedance for the foundation pile below the reflecting surface according to the reflecting surface foundation pile integrity coefficient, carrying out discretization treatment on the foundation pile above the reflecting surface, and introducing pile-soil interaction according to pile soil surrounding property parameters to obtain a reflecting surface reflection wave vibration speed response calculation curve at a pile top mass point;
step 6, analyzing an attenuation coefficient of waves under the pile-soil interaction according to the particle vibration speed response calculation curve, and correcting the complete coefficient of the reflecting surface foundation pile by using the attenuation coefficient to obtain the complete coefficient of the reflecting surface foundation pile introducing the influence of the pile-soil interaction;
and 7, judging the defect degree of the foundation pile according to the integrity coefficient of the reflection surface foundation pile influenced by the introduced pile-soil interaction.
The invention has the beneficial effects that: and obtaining a foundation pile integrity coefficient estimated value without considering the interaction influence of the pile and the soil by using the ratio of the first reflected wave particle vibration speed peak value of the pile body to the first wave particle vibration speed peak value, and setting the change of the pile body section wave impedance below the reflecting surface by using the foundation pile integrity coefficient estimated value. The method can effectively solve the problems that the pile integrity coefficient is analyzed directly by the ratio of the first wave particle vibration speed peak value to the particle vibration speed peak value of the first reflected wave of the pile body without considering the pile-soil interaction influence, and the waveform fitting analysis method is easy to mistakenly take the response curve abnormality caused by the interference of other factors as the response fitting of effective reflected waves.
On the basis of the technical scheme, the invention can be further improved as follows.
Further, the step 1 specifically comprises:
the method comprises the steps of exciting vibration at the center of a detected foundation pile through a hand hammer, acquiring particle acceleration data through an acceleration sensor arranged at the pile top of the foundation pile, and integrating the acceleration data to obtain a particle vibration speed response curve of the pile top of the foundation pile.
Further, step 3 specifically comprises:
and calculating the average velocity of wave propagation in the pile body according to the time corresponding to the response peak value of the mass point vibration velocity of the reflected wave at the bottom of the pile and the time difference corresponding to the peak value of the vibration velocity of the mass point of the first reflected wave of the pile body, and determining the position of the reflecting surface according to the time difference corresponding to the peak value of the vibration velocity of the mass point of the first reflected wave of the pile body and the average velocity.
Further, step 4 specifically comprises:
and calculating the ratio of the peak value of the particle vibration speed of the first reflected wave of the pile body to the peak value of the first wave particle vibration speed to obtain a first ratio, and analyzing the integrity coefficient of the foundation pile of the reflecting surface without considering the interaction condition of the pile and the soil according to the first ratio.
The method has the advantages that the integral coefficient of the reflecting surface foundation pile obtained without considering the pile-soil interaction influence can provide a predicted value for a subsequent correction method, and the corrected integral coefficient of the reflecting surface foundation pile has higher precision than the predicted value due to the introduction of the pile-soil interaction influence on wave propagation.
Further, step 5 specifically comprises:
dispersing foundation piles above a reflecting surface into foundation pile units with equal length, determining pile-soil interaction damping pot model parameters of each foundation pile unit according to pile peripheral soil shear wave velocity and pile peripheral soil shear wave density, obtaining equivalent rapping force pulses according to pile top surface wave impedance and first wave particle vibration velocity of the foundation pile, and obtaining a particle vibration velocity response calculation curve of reflecting surface reflecting waves at the pile top of the foundation pile based on a one-dimensional wave equation characteristic line calculation method according to pile section wave impedance below the reflecting surface, pile-soil interaction damping pot model parameters and the equivalent rapping force pulses which are preset by a pre-estimated value of a foundation pile integrity coefficient of the reflecting surface without considering influence of pile-soil interaction.
Further, step 6 specifically comprises:
and calculating the ratio of the particle vibration speed peak value of the reflected wave and the head wave according to the particle vibration speed response calculation curve of the pile top of the foundation pile to obtain a second ratio, determining the attenuation coefficient of the wave under the pile-soil interaction according to the first ratio and the second ratio, correcting the first ratio according to the attenuation coefficient, and obtaining the complete coefficient of the foundation pile of the reflecting surface, which introduces the pile-soil interaction influence, according to the corrected first ratio.
Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
FIG. 1 is a schematic flow chart of a method for rapidly analyzing integrity coefficients of foundation piles by introducing pile-soil interaction according to an embodiment of the present invention;
FIG. 2 is an exemplary graph of a diameter-reduced pile top particle vibration velocity response test curve provided by an embodiment of a rapid analysis method for integrity coefficients of a foundation pile with introduced pile-soil interaction according to the present invention;
FIG. 3 is an exemplary graph of the vibration velocity peak of the first reflected wave particle of the pile body according to an embodiment of the method for rapidly analyzing the integrity coefficient of the foundation pile by introducing the pile-soil interaction;
fig. 4 is an exemplary diagram of a preset impedance change model, unit numbers and a pile-soil interaction model provided by an embodiment of the method for rapidly analyzing the integrity coefficient of a foundation pile with introduced pile-soil interaction according to the present invention.
In the drawings, the components represented by the respective reference numerals are listed below:
1. pile unit, 2 pile side resistance, 3 pile unit number, 4 pile side pile soil interaction damping kettle model.
Detailed Description
The principles and features of this invention are described below in conjunction with the following drawings, which are set forth to illustrate, but are not to be construed to limit the scope of the invention. As shown in fig. 1, a method for rapidly analyzing the integrity factor of a foundation pile by introducing pile-soil interaction includes:
step 5, presetting pile section wave impedance for the foundation pile below the reflecting surface according to the reflecting surface foundation pile integrity coefficient, carrying out discretization treatment on the foundation pile above the reflecting surface, and introducing pile-soil interaction according to pile soil surrounding property parameters to obtain a reflecting surface reflection wave vibration speed response calculation curve at a pile top mass point;
step 6, analyzing the attenuation coefficient of waves under the interaction of pile and soil according to the particle vibration speed response calculation curve, and correcting the integrity coefficient of the reflecting surface foundation pile by using the attenuation coefficient to obtain the integrity coefficient of the reflecting surface foundation pile introduced into the interaction of the pile and soil;
and 7, judging the defect degree of the foundation pile according to the integrity coefficient of the reflection surface foundation pile influenced by the introduced pile-soil interaction.
In some possible embodiments, a pile body section wave impedance below the reflecting surface is set by the pile body complete coefficient estimated value when the pile soil interaction is not considered. The method can effectively solve the problems that the pile integral coefficient is analyzed directly by the ratio of the first wave particle vibration speed peak value to the particle vibration speed peak value of the first reflected wave of the pile body, the pile-soil interaction influence is not considered, and the waveform fitting analysis method is easy to mistakenly take response curve abnormity caused by other factor interference as effective reflected wave response fitting.
It should be noted that, in the following description,
the time difference T corresponding to the peak value of the pile bottom reflected wave and the peak value of the first wave in the response test curve of the pile top particle vibration speed and the detected foundationPile design length L determines average wave velocity
The specific formula is as follows:
the first reflected wave peak value of the pile body corresponds to the time difference T of the head wave peak valuerAnd determining the position s of the reflecting surface by the average wave speed, wherein the specific formula is as follows:
the first reflection wave peak amplitude V of the pile body is not considered to be attenuated by the pile-soil interactionRAmplitude V of head waveIObtaining the complete coefficient beta of the reflecting surface foundation pile0The concrete formula is as follows:
wherein the content of the first and second substances,
reflection surface foundation pile integrity factor beta0Is the wave impedance Z of the section of the pile below the reflecting surface2Wave impedance Z of the section of the pile above the reflecting surface1The ratio of the first to the second,
pile integrity factor beta from reflecting surface0And wave impedance Z of the section of the pile above the reflecting surface1Wave impedance Z of pile section below preset reflecting surface2
The piles with the length s from the top surface of the pile to the reflecting surface are dispersed into a group of pile units with the same length, see a component 1 in fig. 4, and the specific formula of the length delta L of each pile unit is as follows:
wherein N is the number of pile units divided by s sections of length;
calculating the propagation time delta tau of the wave to and fro in the pile unit according to the average wave speed, wherein the specific formula is as follows:
resampling the head-wave rise-band at delta tau time intervals, using tPRepresenting the time interval from the initial point of the head wave to the peak point; resampling point NsThe specific formula of (A) is as follows:
where the symbol int (#) represents rounding the calculated value.
Time t of jth resampling pointj＝jΔτ(j＝0,1,…Ns) The resampling point is between two adjacent discrete points j of the particle vibration speed response test curve0And j0A temperature of +1, wherein,
delta t is a sampling period of a particle vibration speed response test curve, namely a discrete point time interval;
obtaining the particle vibration speed of the jth resampling point according to the linear interpolation
The specific formula is as follows:
wherein the content of the first and second substances,
the vibration velocity of the particle at the jth resampling point, Vm(j0Δt)、Vm[(j0+1)Δt]Respectively represent the response test curve of the particle vibration velocity0And j0+1 discrete point particle vibration velocity.
To reduce the impact of pile body reflection waves near the pile top and pile soil interaction on the knocking pulse, [0, tp]The interval first wave particle vibration speed response is constructed by t-tpThe bell-shaped pulse as the symmetry axis is used for calculating the equivalent knock force pulse F (t) from the vibration speed of the bell-shaped pulse particle and the wave impedance of the pile top surfacen) The following formula:
wherein Z istop＝(ρcA)topIs the pile top surface wave impedance, rho is the density of the pile top concrete, c is the wave velocity of the pile top surface concrete, A is the pile top cross-sectional area, tnN Δ τ denotes the nth discrete point time, F (t)n) The equivalent knocking force is the nth discrete point;
according to a site-to-ground survey report, according to a shear wave velocity value range in the soil property suggested in GB50111-2006 railway engineering earthquake-resistant design specifications, taking the lower limit average value and the upper limit average value of the shear wave velocity value range as the shear wave velocity of the soil of the layer, and then calculating a damping pot coefficient in a pile-soil interaction model around each pile unit and a damping pot coefficient in the unit length of the interface of the ith pile unit according to the density of the soil layer around the pile, the shear wave velocity and the pile perimeter;
Js,i＝liρs,ics,i
in the formula IiI-th boundary surface side perimeter ρs,iAnd cs,iRepresenting the density and shear wave speed of the soil layer where the section is located;
and obtaining a pile top particle vibration speed response calculation curve by using a one-dimensional wave equation characteristic line solving method according to the equivalent knocking force pulse, the parameters of the pile-soil interaction damping kettle model, the preset wave impedance of the pile body below the reflecting surface and the continuous conditions of the vibration speeds of the upper and lower section particles at the reflecting surface.
In order to obtain the vibration velocity response of the pulse particles completely reflected by the wave on the reflecting surface, the calculation time length is taken as follows:
tc＝ts+5tp
one round-trip time t of wave from pile top to reflecting surfacesComprises the following steps:
by the symbol VR,cThe peak value of the vibration velocity of the mass point of the reflected pulse of the response calculation curve of the vibration velocity of the mass point at the top of the pile is shown as VR,cPeak value V of vibration velocity of mass point of first waveIRatio alphacComprises the following steps:
under the interaction of pile and soil, the wave is attenuated in the process of back and forth propagation from the pile top to the reflecting surface, and the peak value ratio alphac＜α0Attenuation coefficient of amplitude of reflected wave χ
Utilizing an attenuation coefficient chi to obtain a ratio alpha of the first reflected wave of the pile body to the vibration velocity peak value of the head wave mass point0The peak value ratio of the vibration speed of the first reflected wave and the first wave particle of the pile body influenced by the interaction of introduced pile and soil is converted
Then the integrity coefficient beta of the reflecting surface foundation pile is measured0Expression formula
Alpha in (A)0By using
Replacing to obtain the complete coefficient correction value of the foundation pile with the introduced pile-soil interaction
Preferably, in any of the above embodiments, step 1 specifically is:
the method comprises the steps of exciting vibration at the center of a detected foundation pile through a hand hammer, acquiring particle acceleration data through an acceleration sensor arranged at the pile top of the foundation pile, and integrating the acceleration data to obtain a particle vibration speed response curve of the pile top of the foundation pile.
Preferably, in any of the above embodiments, step 3 is specifically:
and calculating the average velocity of wave propagation in the pile body according to the time corresponding to the response peak value of the mass point vibration velocity of the reflected wave at the bottom of the pile and the time difference corresponding to the peak value of the vibration velocity of the mass point of the first reflected wave of the pile body, and determining the position of the reflecting surface according to the time difference corresponding to the peak value of the vibration velocity of the mass point of the first reflected wave of the pile body and the average velocity.
Preferably, in any of the above embodiments, step 4 is specifically:
and calculating the ratio of the peak value of the particle vibration speed of the first reflected wave of the pile body to the peak value of the first wave particle vibration speed to obtain a first ratio, and analyzing the integrity coefficient of the foundation pile of the reflecting surface without considering the interaction condition of the pile and the soil according to the first ratio.
In some possible embodiments, obtaining the reflecting surface foundation pile integrity coefficient without considering the pile-soil interaction influence can provide a pre-estimated value for a subsequent correction method, and the corrected reflecting surface foundation pile integrity coefficient has higher precision than the pre-estimated value due to the introduction of the pile-soil interaction influence on wave propagation.
It should be noted that, regardless of the influence of pile-soil interaction, the integrity coefficient of the foundation pile of the reflecting surface determined according to the first ratio is specifically:
the first reflected wave peak value of the pile body corresponds to the time difference T of the head wave peak valuerAnd determining the position s of the reflecting surface by the average wave speed, wherein the specific formula is as follows:
the first reflection wave peak amplitude V of the pile body is not considered to be attenuated by the interaction of waves on the pile soilRAmplitude V of head waveIObtaining the complete coefficient beta of the reflecting surface foundation pile0The concrete formula is as follows:
wherein the content of the first and second substances,
reflection surface foundation pile integrity factor beta0Is the wave impedance Z of the section of the pile below the reflecting surface2Wave impedance Z of the section of the pile above the reflecting surface1The ratio of the first to the second,
preferably, in any of the above embodiments, step 5 is specifically:
dispersing foundation piles above a reflecting surface into foundation pile units with equal length, determining pile-soil interaction damping pot model parameters of each foundation pile unit according to pile peripheral soil shear wave velocity and pile peripheral soil shear wave density, obtaining equivalent rapping force pulses according to pile top surface wave impedance and first wave particle vibration velocity of the foundation pile, and obtaining a particle vibration velocity response calculation curve of reflecting surface reflecting waves at the pile top of the foundation pile based on a one-dimensional wave equation characteristic line calculation method according to pile section wave impedance below the reflecting surface, pile-soil interaction damping pot model parameters and the equivalent rapping force pulses which are preset by a pre-estimated value of a foundation pile integrity coefficient of the reflecting surface without considering influence of pile-soil interaction.
According to a site-to-ground survey report, according to a shear wave velocity value range in the soil property suggested in GB50111-2006 railway engineering earthquake-resistant design specifications, taking the average value of the lower limit and the upper limit of the shear wave velocity value range as the shear wave velocity of the soil layer, and then calculating the damping pot coefficient in the pile-soil interaction model around each pile unit and the damping pot coefficient in the unit length of the interface of the ith pile unit according to the density of the soil layer around the pile unit, the shear wave velocity and the pile perimeter;
Js,i＝liρs,ics,i
in the formula IiI-th boundary surface side perimeter ρs,iAnd cs,iRepresenting the density and shear wave speed of the soil layer where the section is located;
and obtaining a pile top particle vibration speed response calculation curve by using a one-dimensional wave equation characteristic line solving method according to the equivalent knocking force pulse, the parameters of the pile-soil interaction damping kettle model, the preset wave impedance of the pile body below the reflecting surface and the continuous conditions of the vibration speeds of the upper and lower section particles at the reflecting surface.
Preferably, in any of the above embodiments, step 6 is specifically:
and calculating the ratio of the particle vibration velocity peak value of the reflected wave and the head wave according to the particle vibration velocity response calculation curve of the pile top of the foundation pile to obtain a second ratio, determining the attenuation coefficient under the pile-soil interaction according to the first ratio and the second ratio, correcting the first ratio according to the attenuation coefficient, and calculating the complete coefficient of the foundation pile of the reflecting surface introducing the pile-soil interaction influence according to the corrected first ratio.
It should be noted that the calculation of the integrity coefficient of the foundation pile of the reflecting surface under the influence of the introduced pile-soil interaction according to the corrected first ratio specifically includes:
under the interaction of pile and soil, the wave is attenuated in the process of back and forth propagation from the pile top to the reflecting surface, and the peak value ratio alphac＜α0Attenuation coefficient of amplitude of reflected wave χ
Utilizing an attenuation coefficient chi to obtain a ratio alpha of the first reflected wave of the pile body to the vibration velocity peak value of the head wave mass point0The peak value ratio of the vibration speed of the first reflected wave and the first wave particle of the pile body influenced by the interaction of introduced pile and soil is converted
Then the integrity coefficient beta of the reflecting surface foundation pile is measured0Expression formula
Alpha in (A)0By using
Replacing to obtain the complete coefficient correction value of the foundation pile after the interaction of the introduced pile and the soil
Example 1, in step 1, a diameter-reduced model pile length L is 8m, a pile top section diameter D is 2R is 0.4m, a constriction is arranged in a range of 4m to 4.5m from the pile top, and soil around the pile is backfill soil; the pile top accelerometer is adhered with plasticine at the center of the pile
Nearby position, beating with hammer at pile center, recording mass point vibration acceleration response by foundation pile dynamic tester, sampling time interval delta t is 2X 10-5s, integrating the acceleration response curve to obtain a mass point vibration speed response test curve, carrying out 2000Hz low-pass filtering on the mass point vibration speed response test curve, and carrying out vibration treatment on the mass pointsThe speed response test curve is shown in figure 2;
Step 5, taking the wave impedance Z of the section of the pile above the reflection surface1＝ZtopEstimating value beta according to pile integrity factor0The impedance of the pile wave below the reflection surface is preset to Z as 0.822＝0.82×ZtopReferring to fig. 4, reference numeral 1 denotes a group of equal-length pile units, reference numeral 2 denotes pile-side resistance, reference numeral 3 denotes pile unit numbers, and reference numeral 4 denotes a pile-side pile-soil interaction damping pot model; taking N as 50, pile unit length Delta L as s/N as 3.87/50 as 0.0774m, and taking Z as wave impedance of each pile unit above the reflecting surfacetop(ii) a Resampling the response test curve of the head wave particle vibration speed with sampling interval
Number of head wave resampling points
From ZpotAnd calculating the equivalent pulse force by the response of the vibration speed of the head wave mass point. Pile-taking peripheral backfill density rhos＝1800kg/m3Shear wave velocity csCalculating the coefficient of a pile-side damping kettle at 80m/s, and obtaining a pile-soil interaction pile top mass point vibration speed response calculation curve introduced by equivalent pulse force, pile-soil interaction model damping kettle parameters, preset wave impedance change and continuous conditions of upper and lower section mass point vibration speeds at a reflecting surface based on a one-dimensional wave equation characteristic line solving method;
step 6, calculating the time length of the curve
Calculating the ratio alpha of the peak value of the vibration velocity of curve reflected wave and head wave mass pointc0.115, under the interaction of pile and soil, the peak attenuation coefficient chi of the reflected wave is alphac/α00.581, the ratio of the vibration velocity peak value of the reflected wave to the vibration velocity peak value of the head wave mass point after correction
Correction value of integrity coefficient of foundation pile with reflecting surface
And the model pile setting parameters are basically matched.
It is understood that some or all of the alternative embodiments described above may be included in some embodiments.
It should be noted that the above embodiments are product embodiments corresponding to the previous method embodiments, and for the description of each optional implementation in the product embodiments, reference may be made to corresponding descriptions in the above method embodiments, and details are not described here again.
The above method, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention essentially or partially contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.
The above is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the present invention, and these modifications or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (6)
1. A method for rapidly analyzing the integrity coefficient of a foundation pile by introducing pile-soil interaction is characterized by comprising the following steps:
step 1, obtaining a particle vibration speed response curve of the pile top of a detected foundation pile;
step 2, determining the peak value and the peak value corresponding time of the first wave particle vibration speed, the peak value and the peak value corresponding time of the particle vibration speed of the first reflected wave of the pile body and the peak value corresponding time of the particle vibration speed of the reflected wave of the pile bottom according to the particle vibration speed response curve;
step 3, determining the position of a reflecting surface according to the time corresponding to the peak value of the vibration velocity of the primary wave mass point, the time corresponding to the peak value of the vibration velocity of the first reflected wave of the pile body, the time corresponding to the peak value of the vibration velocity response of the mass point of the reflected wave at the bottom of the pile and the design length of the detected foundation pile;
step 4, determining a reflection surface foundation pile integrity coefficient without considering the interaction influence of pile and soil according to the ratio of the mass point vibration velocity peak value of the first reflected wave of the pile body to the head wave mass point vibration velocity peak value;
step 5, presetting pile section wave impedance for the foundation pile below the reflecting surface according to the reflecting surface foundation pile integrity coefficient, carrying out discretization treatment on the foundation pile above the reflecting surface, and introducing pile-soil interaction according to pile soil surrounding property parameters to obtain a reflecting surface reflecting wave vibration speed response calculation curve at the pile top mass point of the foundation pile;
step 6, analyzing an attenuation coefficient of waves under the pile-soil interaction according to the particle vibration speed response calculation curve, and correcting the complete coefficient of the reflecting surface foundation pile by using the attenuation coefficient to obtain the complete coefficient of the reflecting surface foundation pile introducing the influence of the pile-soil interaction;
and 7, judging the defect degree of the foundation pile according to the integrity coefficient of the reflection surface foundation pile influenced by the introduced pile-soil interaction.
2. The method for rapidly analyzing the integrity coefficient of the foundation pile with the introduced pile-soil interaction according to claim 1, wherein the step 1 specifically comprises the following steps:
the method comprises the steps of exciting vibration at the center of a detected foundation pile through a hand hammer, acquiring particle acceleration data through an acceleration sensor arranged at the pile top of the foundation pile, and integrating the acceleration data to obtain a particle vibration speed response curve of the pile top of the foundation pile.
3. The method for rapidly analyzing the integrity factor of the foundation pile with the introduced pile-soil interaction according to claim 1, wherein the step 3 specifically comprises the following steps:
and calculating the average velocity of wave propagation in the pile body according to the time corresponding to the response peak value of the mass point vibration velocity of the reflected wave at the bottom of the pile and the time difference corresponding to the peak value of the vibration velocity of the mass point of the first reflected wave of the pile body, and determining the position of the reflecting surface according to the time difference corresponding to the peak value of the vibration velocity of the mass point of the first reflected wave of the pile body and the average velocity.
4. The method for rapidly analyzing the integrity factor of the foundation pile with the introduced pile-soil interaction according to claim 1, wherein the step 4 specifically comprises the following steps:
and calculating the ratio of the peak value of the particle vibration speed of the first reflected wave of the pile body to the peak value of the first wave particle vibration speed to obtain a first ratio, and analyzing the integrity coefficient of the foundation pile of the reflecting surface without considering the interaction influence of the pile and the soil according to the first ratio.
5. The method for rapidly analyzing the integrity factor of the foundation pile with the introduced pile-soil interaction according to claim 3, wherein the step 5 specifically comprises the following steps:
dispersing foundation piles above a reflecting surface into foundation pile units with equal length, determining pile-soil interaction damping kettle model parameters of each foundation pile unit according to pile peripheral soil shear wave velocity and pile peripheral soil shear wave density, obtaining equivalent tapping force pulses according to pile top surface wave impedance and first wave particle vibration velocity, and obtaining a particle vibration velocity response calculation curve of reflecting surface reflecting waves at the pile top of the foundation pile based on a one-dimensional wave equation characteristic line calculation method according to pile section wave impedance below the reflecting surface, pile-soil interaction damping kettle model parameters and the equivalent tapping force pulses preset according to a pre-estimated value of a foundation pile integrity coefficient of the reflecting surface without considering influence of pile-soil interaction.
6. The method for rapidly analyzing the integrity factor of the foundation pile with the introduced pile-soil interaction according to claim 4, wherein the step 6 specifically comprises the following steps:
and calculating the ratio of the particle vibration velocity peak value of the reflected wave and the head wave according to the particle vibration velocity response calculation curve of the pile top of the foundation pile to obtain a second ratio, determining the attenuation coefficient of the wave under the influence of the pile-soil interaction according to the first ratio and the second ratio, correcting the first ratio according to the attenuation coefficient, and calculating the complete coefficient of the foundation pile of the reflecting surface introducing the influence of the pile-soil interaction according to the corrected first ratio.
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