CN-121115123-B - Method for realizing ocean geological detection by hammering pile foundation excitation signals

CN121115123BCN 121115123 BCN121115123 BCN 121115123BCN-121115123-B

Abstract

The invention relates to the technical field of ocean geology detection, in particular to a method for realizing ocean geology detection by hammering pile foundation excitation signals, which comprises the steps of arranging a plurality of acceleration sensors at intervals along different depths of a pile body on a driven target pile foundation to form a longitudinal receiving array, synchronously arranging the longitudinal receiving arrays on a plurality of adjacent pile foundations to form a pile group collaborative observation network, collecting pile foundation vibration response in the construction process in real time, combining a wave field separation and a multi-point joint inversion technology, fully playing the natural coupling effect of sea water and the pile group collaborative advantage, realizing high-precision three-dimensional imaging of a stratum structure and geological characteristics among piles, ensuring the construction progress, simultaneously taking into account low cost and high-precision geological imaging, and solving the problems of insufficient exploration precision, limited construction efficiency and high cost in the prior art.

Inventors

ZHANG XIANQI
LUO YI
ZHANG JINRUI
Gong Hangli
LUO HAN
MENG FEI
LIU YIRAN

Assignees

武汉理工大学三亚科教创新园

Dates

Publication Date: 20260512
Application Date: 20251112

Claims (8)

1. A method for realizing ocean geological detection by using hammering pile foundation excitation signals is characterized by comprising the following steps: s1, arranging a plurality of acceleration sensors at intervals along different depths of a pile body on a driven target pile foundation to form a longitudinal receiving array, and synchronously arranging the longitudinal receiving arrays on a plurality of adjacent pile foundations to form a pile group collaborative observation network; S2, in the piling construction process, a plurality of longitudinal receiving arrays acquire original vibration signals respectively; s3, preprocessing an original vibration signal, and performing time-frequency analysis on the preprocessed signal; S4, performing wave field separation based on the original vibration signals acquired by the longitudinal receiving array, constructing a pile foundation-stratum-water body coupling propagation model, performing wave field forward computation, and providing basic data for subsequent inversion and geological imaging; S5, constructing a single-point inversion objective function, calculating the sensitivity of the single-point inversion objective function to the wave speed parameter, carrying out iterative updating on the single-point inversion objective function according to the sensitivity, and introducing a regularization term into the single-point inversion objective function after iterative updating; S6, constructing a multipoint inversion objective function, and inputting the original vibration signals acquired by the longitudinal receiving array into the multipoint inversion objective function for joint inversion; and S7, generating a stratum velocity profile and an impedance profile between piles based on the joint inversion result, and constructing three-dimensional geological imaging.
2. The method for achieving marine geology detection using hammering pile foundation excitation signals according to claim 1, wherein in S2, the original vibration signals are original vibration signal matrixes in time series form , Expressed as: ; Wherein, the To lay out the total number of sensors; Is the transpose of the matrix; is the first The raw acceleration time course of the individual sensors, 。
3. The method for achieving ocean geology detection by using hammering pile foundation excitation signals according to claim 1, wherein in the step S3, the preprocessing process of the original vibration signals sequentially comprises band-pass filtering, wavelet decomposition, high-frequency suppression, inverse wavelet transformation and normalization processing, and the process of performing time-frequency analysis on the preprocessed signals comprises the steps of converting the normalized signals into time-frequency energy spectrums by using Hilbert-Huang transform, and extracting main frequency bands, energy concentration areas and duration time characteristics from the time-frequency energy spectrums.
4. A method for implementing marine geological exploration using hammering pile foundation excitation signals according to claim 3, wherein in said S3, the process of preprocessing the original vibration signal is as follows: ① For the first Raw acceleration time course of individual sensors The band-pass filtering is carried out, and the calculation formula of the band-pass filtering is as follows: ; Wherein, the Is a band-pass filtered signal; 、 the lower cut-off frequency and the upper cut-off frequency of band-pass filtering are respectively adopted; ② For band-pass filtered signals And performing multi-scale wavelet decomposition, wherein the calculation formula is as follows: ; Wherein, the Is the first A layer approximation component; is the first A layer detail component; ③ For each layer of detail coefficients using a threshold function High frequency suppression is performed, and the calculation formula is as follows: ; Wherein, the Is the first after thresholding A layer detail component; as a soft threshold function; ④ Coefficient after thresholding Coefficient of approximation to original Performing inverse wavelet transform together to obtain denoising signal data The calculation formula is as follows: ; ⑤ For denoising signal data And carrying out normalization processing, wherein a normalization calculation formula is as follows: ; Wherein, the Is normalized to the first The number of variables that can be used, And Respectively denoising signal data And the maximum and minimum values of (a) are set.
5. The method for implementing marine geological exploration using hammering pile foundation excitation signals according to claim 4, wherein in said S3, the process of performing time-frequency analysis on the preprocessed signals is as follows: ① For the acceleration signal after normalization processing Empirical mode decomposition is performed, and a decomposition calculation formula is as follows: ; Wherein, the As a residual component of the residual component, The number of IMFs obtained for decomposition; is the first Each eigenmode component; ② Performing Hilbert transform on each IMF to calculate an analytic signal Resolving signals The calculation formula of (2) is as follows: ; Wherein, the To resolve the signal; Is an imaginary unit; For the hilbert transform, expressed as: ; Wherein, the Integrating the principal value; Is an integral variable; is the current time variable; ③ Calculating instantaneous amplitude The calculation formula is as follows: ; ④ Constructing a time-frequency energy spectrum The following is shown: ; Wherein, the Is a Hilbert spectrum; is a dirac function; is the first Energy of the individual IMF components; ⑤ Extracting the primary frequency band The calculation formula is as follows: ; Wherein, the Is the main frequency band; extraction of time-frequency energy density distribution Satisfy the following requirements As an energy concentration region, wherein, As a result of the threshold value being set, Is the maximum value of energy in the time-frequency energy spectrum; The point in time at which the extracted energy decays to a proportion of the initial value is taken as a duration feature.
6. The method for achieving marine geology detection using hammering pile foundation excitation signals according to claim 1, wherein in said S4, the wave field separation process is as follows: Multi-channel wave field separation is carried out on the multi-point signals acquired by the longitudinal array, longitudinal wave and transverse wave components are identified and extracted, and the calculation formula is as follows: ; Wherein, the The longitudinal wave signal component matrix is obtained after the longitudinal wave projection operator is processed; is a longitudinal wave projection operator; The method comprises the steps of acquiring an original acceleration signal matrix for a longitudinal array in a multipoint manner; The transverse wave signal component matrix is obtained after the transverse wave projection operator is processed; is a transverse wave projection operator; Is a time variable; The process of constructing the coupling propagation model of pile foundation, stratum and water body is as follows: The first step, the research area is discretized into two-dimensional or three-dimensional grids, and each unit is endowed with a wave velocity parameter to be solved And build a theoretical travel time The calculation formula of (2) is as follows: ; Wherein, the Is the first A ray path; Is the wave velocity distribution along the path; secondly, determining the following main parameters according to actual sea areas and pile foundation conditions: parameters of the water layer including sound velocity Thickness of water layer ; Formation parameters longitudinal wave velocity of each layer of medium Velocity of transverse wave Density of Interface depth and preliminary impedance distribution; Pile parameters, namely longitudinal wave speed of concrete Velocity of transverse wave Density of Geometric features; thirdly, constructing a coupling propagation model of pile foundation, stratum and water body, wherein the coupling propagation model comprises the following steps: the program function equation is established as follows: ; Wherein, the Is the theoretical travel time; time to a wavefront reaching a point; for the wave velocity of the point, Can be expressed as: ; Wherein, the Representing vertical space coordinates or depth variables; The equations for the snell's law are established as follows: ; Wherein, the The incident angle and the refraction angle are respectively set, Respectively the wave velocities of different media, Is a slowness constant; The ray equation is established as follows: ; Wherein, the Is a slowness vector; Is a ray arc length parameter; is a three-dimensional space position vector; The acoustic equation for the water body region is established as follows: ; Wherein, the Is a sound pressure field; is a source function; the elastic wave equation applicable to the stratum area and the pile body area is established as follows: ; Wherein, the In order to achieve a medium density of the material, As a tensor of the modulus of elasticity, As a result of the displacement vector being a function of the displacement vector, Is excited by external force; the reflection coefficient approximation equation is established as follows: ; Wherein, the As a function of the angle of incidence, Is the incident angle The reflection coefficient of the longitudinal wave is lower, And The longitudinal wave velocity and density differences between the media, respectively.
7. The method for achieving ocean geology detection using hammering pile foundation excitation signals according to claim 1, wherein in S5, a single point inversion objective function is constructed as follows: ; Wherein, the Inverting the objective function for a single point; the number of observation points participating in inversion; is the first Actually measured travel time data acquired by the observation points; for the current wave velocity field A theoretical travel time signal obtained through forward calculation is downloaded; is a wave velocity parameter; calculating a single point inversion objective function For wave velocity parameters The sensitivity of (2) is calculated as follows: ; Wherein, the Is sensitivity distribution; is a companion field; is full-wavefield data; Is a time variable; According to the sensitivity distribution information, carrying out iterative updating on the single-point inversion objective function, wherein the calculation formula of the iterative updating is as follows: ; Wherein, the The updated wave velocity field; is the first Wave velocity field during the second iteration; Is a step factor; the gradient of the objective function, namely the sensitivity, is calculated under the current model; introducing regularization terms and constraint conditions into the iteratively updated single-point inversion objective function, and introducing the regularized objective function Can be expressed as: ; Wherein, the Is a regularization coefficient; Is a regularization term.
8. The method for achieving marine geology detection using hammering pile foundation excitation signals according to claim 1, wherein in S6, a multi-point inversion objective function is constructed as follows: ; Wherein, the Inverting the objective function for multiple points; The number of pile foundations involved in joint inversion; is the first The number of sensors arranged on the root pile; Is a regularization coefficient; Is a regularization term; And Is a waveform response.

Description

Method for realizing ocean geological detection by hammering pile foundation excitation signals Technical Field The invention relates to the technical field of ocean geology detection, in particular to a method for realizing ocean geology detection by using hammering pile foundation excitation signals. Background As a core bearing structure of a great marine infrastructure such as an offshore wind farm, a cross-sea bridge, a deep water port, a marine oil-gas engineering and the like, the construction quality of a pile foundation is closely related to stratum conditions. However, complex offshore geological environments often represent special strata such as uneven sediment thickness, frequent soft and hard interbedding, sludge inclusion, drifting and the like, and these characteristics not only affect the piling quality and bearing performance of the pile foundation, but also directly relate to the safety and economy of engineering. Pile foundation construction usually adopts a hammering or vibrating pile sinking mode, and the process inevitably generates strong disturbance on a pile body and surrounding stratum. How to effectively utilize the dynamic response of pile foundation excitation in the construction process, develop the detection and inversion of stratum structure and geological characteristics between piles, and have important significance for guaranteeing the safety, economy and construction efficiency of offshore foundation engineering. The traditional marine geological exploration mainly depends on methods such as seismic exploration, sonar detection, drilling sampling and the like, wherein the seismic exploration and the sonar detection can cover a larger range, but are limited by problems of seabed noise interference, insufficient resolution, complex equipment layout and the like, the requirement of near-field high-precision imaging in pile foundation construction is difficult to meet, and the drilling sampling method can obtain more direct geological data, but has limited point positions, large construction interference and high cost, and is difficult to realize large-range and real-time stratum information acquisition. In summary, the existing offshore pile foundation construction conditions often have the defects of insufficient exploration precision, limited construction efficiency, high cost and the like, so that the technical problem of how to consider low-cost and high-precision geological imaging while guaranteeing the construction progress is still needed to be solved. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a method for realizing marine geological exploration by hammering pile foundation excitation signals, which is characterized in that a sensor array is arranged on a driven pile foundation, the pile foundation vibration response in the construction process is acquired in real time, the natural coupling effect of seawater and the cooperative advantage of pile groups are fully exerted by combining a wave field separation and multipoint joint inversion technology, the high-precision three-dimensional imaging of the stratum structure and geological characteristics among piles is realized, the construction progress is ensured, and meanwhile, the low-cost and high-precision geological imaging is realized, so that the problems of insufficient exploration precision, limited construction efficiency and high cost in the prior art are solved. In order to achieve the above purpose, the present invention adopts the following technical scheme: A method for realizing ocean geological detection by using hammering pile foundation excitation signals comprises the following steps: S1, arranging a plurality of acceleration sensors at intervals along different depths of a pile body on a driven target pile foundation to form a longitudinal receiving array, and synchronously arranging the longitudinal receiving arrays on a plurality of adjacent pile foundations to form a pile group collaborative observation network; S2, in the piling construction process, a plurality of longitudinal receiving arrays acquire original vibration signals respectively; s3, preprocessing an original vibration signal, and performing time-frequency analysis on the preprocessed signal; S4, performing wave field separation based on the original vibration signals acquired by the longitudinal receiving array, constructing a pile foundation-stratum-water body coupling propagation model, performing wave field forward computation, and providing basic data for subsequent inversion and geological imaging; S5, constructing a single-point inversion objective function, calculating the sensitivity of the single-point inversion objective function to the wave speed parameter, carrying out iterative updating on the single-point inversion objective function according to the sensitivity, and introducing a regularization term into the single-point inversion objective function after iterative updatin