13 results about "Dispersion curve" patented technology

One or more embodiments of the invention provide a Scholte wave frequency dispersion curve adaptive inversion method and a related device, and the method comprises the steps: obtaining and processing the original seismic data of a target seabed, and obtaining a Scholte wave frequency dispersion curve; constructing an initial shear wave velocity model through linear inversion based on a Schlte wave frequency dispersion curve; and performing fitting optimization on the Schlte wave frequency dispersion curve based on the initial shear wave velocity model to obtain a two-dimensional shear wave velocity profile. According to the technical scheme, the problem that a traditional linear inversion method depends on an initial model is solved, the calculation efficiency is remarkably improved, the problem of local extremum is avoided, and an automatic high-precision inversion solution suitable for batch data processing is provided for submarine seismic exploration.

The invention provides a frequency dispersion curve calculation method based on a decoupling type Legendre-Gauss-Labatto spectral element method, and belongs to the technical field of discrete solution of guided wave propagation in a thin plate, and the method comprises the following steps: S1, constructing a wave equation which comprises a Cartesian space coordinate system based on an orthotropic plate, and combining a constitutive equation, a geometrical relationship under the coordinate system and guided wave displacement to obtain a wave dispersion curve; substituting into a control equation when the volume force is zero to obtain an improved three-dimensional elastic wave equation; s2, a differential matrix is constructed, wherein discretization and decoupling are carried out on a wave equation on the basis of a Lagrange interpolation basis function of a Legendre-Gauss-Labatto node; s3, explicitly embedding the stress free boundary condition into the solving process through matrix line transformation, and solving to obtain a frequency dispersion curve, the derivation process is simplified, the boundary and the interior of the material are decoupled, and the physical significance is clearer. And meanwhile, the high-precision advantage of the spectrum method is maintained, and the calculation rate is remarkably improved.

The application provides a background noise high-order surface wave dispersion extraction method, and belongs to the technical field of seismology. The method first calculates the cross-correlation function of continuous noise data and performs preprocessing to obtain an original dispersion energy spectrum; then a reference phase shift curve between the energy of the base order and the first high-order mode is extracted; the cross-correlation function is phase-shifted based on the curve, so that the base order and the high-order surface wave are separated in time, the high-order part at the negative time is retained and inverse phase shift is performed, and a cross-correlation function containing only the high-order surface wave is obtained; then the high-order surface wave dispersion energy spectrum is obtained through frequency-Bessel transformation, and is spliced with the base order part in the original spectrum to form an enhanced dispersion energy spectrum; finally, the base order and the high-order dispersion curves are extracted after quality control. The application can effectively suppress the interference of the base order sidelobe on the high-order mode, and significantly improve the continuity and signal-to-noise ratio of the high-order surface wave dispersion energy.

This invention relates to the field of micro-motion surface wave exploration methods, and discloses an automatic extraction method for dispersion curves of micro-motion surface waves based on connected component analysis. The method includes cross-correlation extraction of virtual source surface wave shot gathers, frequency-wavenumber domain amplitude spectrum calculation, adaptive threshold binarization, connected component analysis, frequency-wavenumber domain surface wave mask generation, mask-amplitude matrix element multiplication, phase velocity picking, Hampel filtering, and automatic generation of dispersion curves. This invention utilizes image connected component analysis and other operations to process the amplitude spectrum of micro-motion surface waves, separating the surface wave signal region from the frequency-wavenumber domain amplitude spectrum image. It automatically identifies discrete phase velocity points from images containing only surface wave dispersion energy stripes and uses Hampel filtering to remove distortion points, ultimately achieving high-precision automated measurement of the dispersion curve.

The invention discloses a surface wave frequency dispersion energy spectrum imaging method, system and device for improving F-K transformation resolution based on normalization preprocessing and a medium, and belongs to the technical field of surface wave exploration, and the method comprises the steps: collecting a plurality of seismic records of an acquisition domain; performing normalization preprocessing on the selected seismic record data to obtain preprocessed surface wave data; performing two-dimensional Fourier transform to obtain domain data, and transforming a domain into a domain according to the frequency dispersion characteristic of the surface wave data; and in the phase velocity range of the surface wave, determining a frequency dispersion curve recorded by the surface wave by selecting a peak point corresponding to any frequency in a domain. According to the method, by introducing a normalization preprocessing process, the comprehensive performance of a traditional F-K transformation method in surface wave frequency dispersion energy spectrum imaging is improved, the overall resolution of a frequency dispersion energy spectrum can be enhanced, the recognition capability of high-order mode frequency dispersion energy is improved, and energy spectrum distribution of a base order and a high-order mode is clearly separated.

This invention discloses a method, apparatus, and medium for cross-dimensional Bayesian inversion of Rayleigh surface wave dispersion curves, relating to the field of surface wave exploration technology. This invention introduces a Dix-type physically guided soft prior, using a reference shear wave velocity profile as a probability anchor point to construct a Gaussian probability field around this profile. This guides the cross-dimensional Bayesian inversion to quickly enter a high-probability physically reasonable region in a probabilistic sense, thereby upgrading the Dix non-iterative inversion results from "fixed initial values / hard constraints" to "Gaussian probability anchor point soft priors." Simultaneously, based on the formation depth value corresponding to the subsurface shear wave velocity parameters to be inverted, a depth-related prior standard deviation of the Gaussian probability field is set to ensure the soft prior operates within the physical boundaries. This makes the final inversion results naturally biased towards the physically reasonable model region in a probabilistic sense, and physical boundary constraints are applied, eliminating systematic biases in the Dix inversion and ultimately obtaining inversion results consistent with actual geology.

The present application relates to the technical field of tunnel and underground engineering construction and safety monitoring, and particularly relates to a method and a terminal for determining the boundary of a tunnel surrounding rock pressure arch, comprising: theoretical prediction, field measurement and comparative verification; the present application constructs a comprehensive determination system of the boundary of the tunnel surrounding rock pressure arch by fusing theoretical calculation and field measurement, at the theoretical level, the theoretical boundary of the pressure arch is defined by quantifying the specific proportional position of the radius of the plastic zone and the peak value of the tangential stress of the elastic zone; at the measurement level, the propagation characteristics of the transient Rayleigh surface wave in the non-uniform medium are used to identify the surface of property mutation of the rock mass by capturing the inflection point of the wave velocity changing with depth in the dispersion curve; finally, the theoretical prediction result is compared with the field measurement result for checking, so as to determine the final boundary of the pressure arch.

The one or more embodiments of the present disclosure provide a Scholte wave dispersion curve adaptive inversion method and a related device, the method comprising: obtaining and processing original seismic data of a target seabed to obtain a Scholte wave dispersion curve; constructing an initial shear wave velocity model based on the Scholte wave dispersion curve through linear inversion; and fitting and optimizing the Scholte wave dispersion curve based on the initial shear wave velocity model to obtain a two-dimensional shear wave velocity profile. Through the technical solution of the present disclosure, the problem that the traditional linear inversion method relies on an initial model is solved, the calculation efficiency is significantly improved, and the local extremum problem is avoided, thereby providing an automatic high-precision inversion solution suitable for batch data processing for seabed seismic exploration.

The invention relates to the technical field of tunnel and underground engineering construction and safety monitoring, in particular to a method and terminal for determining the boundary of a tunnel surrounding rock pressure arch, and the method comprises the steps of theoretical prediction, field actual measurement and comparison verification. According to the method, a tunnel surrounding rock pressure arch boundary comprehensive determination system fusing theoretical calculation and field actual measurement is constructed, and on the theoretical level, the theoretical boundary of a pressure arch is defined by quantifying the radius of a plastic zone and the specific proportional position of a tangential stress peak value of an elastic zone; on an actual measurement level, the propagation characteristics of transient Rayleigh surface waves in a non-uniform medium are utilized, and a rock mass property mutation surface is identified by capturing an inflection point of the wave velocity changing along with the depth in a frequency dispersion curve; and finally, comparing and checking a theoretical prediction result with a field actual measurement result to determine a final pressure arch boundary.

This invention discloses a method, device, and medium for joint imaging of micro-motion multi-order SPAC coefficients and video dispersion curves under undulating terrain. The method includes: Step 1, dividing the undulating terrain into multiple local units, calculating the overall surface wave phase velocity, and then obtaining the SPAC coefficients to obtain the theoretical video dispersion curve; Step 2, obtaining the surface normal component from the three-component micro-motion data obtained from micro-motion observations, and extracting the SPAC coefficients and the optimal video dispersion curve under strong constraints of the SPAC coefficient zero point; Step 3, inputting the shear wave velocity of the strata, the elevation of the underlying stratum interface, and the elevation of the undulating terrain surface into a pre-trained LSTM network, and performing joint inversion based on the SPAC coefficients and video dispersion curves to obtain subsurface space imaging. This invention is applicable to undulating terrain conditions and can fully utilize multi-order surface wave dispersion information, exhibiting higher imaging accuracy and stability, thereby achieving high-resolution micro-motion imaging of subsurface space.

The application discloses a joint inversion method based on surface waves and direct P waves, relates to the field of seismic tomography, and comprises data acquisition and processing, separate surface wave and P wave model construction, joint inversion algorithm design and inversion result visualization. The surface wave part adopts a frequency-vector wavenumber domain transformation method to extract a dispersion curve, and solves a model correction amount optimization update of a subsurface medium shear wave velocity through Voronoi inversion; the direct P wave part uses a fast marching method in a PYGIMLI program to calculate a ray path and solves a longitudinal wave velocity through a regularization inversion. Finally, through the joint inversion algorithm, the results of the two wave types are comprehensively analyzed and processed, the velocity and geological layering parameters of the subsurface medium in the road collapse area are accurately estimated, the advantages of the surface wave inversion and the direct P wave inversion are combined, the seismic wave data are comprehensively analyzed and processed, the limitations of the single inversion technology are overcome, and the data noise resistance, the inversion accuracy and the resolution of the subsurface shallow structure are improved.

This invention relates to the field of physical acoustics, and in particular to a method and system for calculating the dispersion relation of Schulte waves on a single-phase medium nonlinear metasurface. The method includes the following steps: obtaining expressions for the displacement and stress components of the single-phase medium under the action of a Schulte wave; obtaining expressions for the fluid displacement component and the fluid normal stress, as well as expressions for the relative motion of the resonator; based on all expressions, applying stress and displacement continuity boundary conditions at the interface between the single-phase medium and the fluid layer to obtain the characteristic equation of the dispersion characteristics of the coupled system, solving it, and finally obtaining the dispersion curve of the coupled system. This invention improves the computational efficiency and prediction accuracy of wave propagation at the interface of a single-phase medium nonlinear metasurface by providing an explicit dispersion relation for Schulte waves on a single-phase medium nonlinear metasurface, which is beneficial for reducing the computational cost and design cycle of acoustic metasurface design, vibration suppression, and waveguide control.