11 results about "Elastic wave velocity" patented technology

The invention relates to the field of rock mechanics testing, in particular to a rock deformation and elastic wave velocity monitoring device and method under dynamic high temperature and high pressure, and the device comprises a clamp, a deformation monitoring assembly and an elastic wave velocity monitoring assembly. The deformation monitoring assembly is used for measuring thermal expansion deformation of the rock sample in the length, width and thickness directions at dynamic high temperature; the elastic wave velocity monitoring assembly is arranged on the rock sample and used for monitoring the elastic wave velocity of the rock sample. According to the monitoring device and method, at any moment, the thermal expansion of the clamp and the thermal expansion of the rod-shaped monitoring assembly offset each other, the thermal expansion deformation of the button and the thermal expansion deformation of the annular frame also offset each other, and the reading change of the displacement and deformation sensor directly and truly reflects the thermal expansion deformation of the rock sample; measurement errors caused by self deformation in the dynamic temperature rise process in the prior art are eliminated, and the accuracy of deformation data capture in the whole process from normal temperature to high temperature is ensured.

The application discloses a kind of embankment quality elastic wave tomography detection methods, comprising: synchronous acquisition compactor vibration source at source end reference signal and the ground surface response signal of measured region surface, establish the unified time base of both;Correlation function of source end reference signal and ground surface response signal is calculated, and the coarse estimation time is determined based on peak value.Extract feature frequency component from signal and obtain analytic signal phase information, calculate the phase difference of ground surface response signal at coarse estimation time relative to source end reference signal, and use the phase difference to determine fine time correction amount.Use fine time correction amount to correct coarse estimation time, obtain final elastic wave time and generate elastic wave velocity distribution image by inversion.The application breaks through the limitation of sampling rate on measurement accuracy by collecting real source end waveform and combining phase refinement technology, and improves the resolution and reliability of compaction quality detection.

This application belongs to the field of landslide prediction technology, and relates to a method for predicting landslides at tunnel entrances using shallow seismic-stress joint inversion. This invention acquires first-arrival wave travel time data of the slope using a high-frequency seismic source array, constructs a geological model including a rock mass integrity coefficient matrix, identifies rock mass structural deterioration through elastic wave velocity distribution, and identifies potential unstable structural weak areas in advance. Then, the rock mass integrity coefficient matrix is ​​embedded as prior knowledge into the stress field solution. By establishing the coupling relationship between seismic wave propagation and stress, the stress field distribution of the slope is inverted, capturing early stress redistribution signals caused by structural deterioration in deep rock masses, achieving early detection of precursors to mechanical instability. Furthermore, based on stress and strain data, the strain energy density distribution of the potential slip surface is calculated. By judging whether the strain energy density exceeds a threshold, whether it is continuous, and whether the expansion rate exceeds the standard, the potential slip surface can be accurately identified before it is fully connected, avoiding the lag caused by relying on displacement signals.

The invention provides an ancient building exterior wall tile weathering degree detection and evaluation method, which comprises the following steps: acquiring a missing volume value, a surface hardness value and an elastic wave velocity value of an ancient building exterior wall tile needing to be evaluated, and calculating a volume missing rate, a surface hardness decrease rate and an elastic wave velocity decrease rate of the ancient building exterior wall tile; according to the relative importance degrees of the volume missing rate, the surface hardness decrease rate and the elastic wave velocity decrease rate in the ancient building weathering degree evaluation, determining the volume missing rate weight, the surface hardness decrease rate weight and the elastic wave velocity decrease rate weight by using an analytic hierarchy process, thereby calculating the weathering index of the ancient building exterior wall tile. Determining the weathering grade of the ancient building exterior wall brick according to the weathering index, and evaluating the weathering degree of the ancient building exterior wall brick by using the weathering grade. The method comprehensively considers three factors of the volume loss rate, the surface hardness decrease rate and the elastic wave velocity decrease rate of the external wall tile to scientifically and comprehensively evaluate the weathering degree of the external wall tile of the ancient building.

The application discloses a karst collapse hidden danger area multi-method cooperative detection method and system, relates to the technical field of geographic detection, and comprises the following steps: arranging an observation network in a target hidden danger area, respectively implementing an electric excitation sequence and a mechanical vibration excitation sequence, collecting potential difference data and vibration waveform data, inverting the potential difference data and the vibration waveform data at each collection time, analyzing the phase relationship and the change form of the resistivity sequence and the elastic wave velocity sequence with respect to the corresponding excitation time sequence, and dividing the area into regions with different response characteristics according to the characteristic differences of the multi-physical field dynamic response modes in space. The application can extract the multi-physical field dynamic response mode representing the dynamics process such as groundwater seepage and particle migration, realize direct description of the dynamics process activity and evolution time sequence in the hidden danger area, and improve the ability of identifying the hidden danger development stage from the physical response.

The invention discloses a real-time monitoring and risk early warning method for corrosion damage of a deep soft rock roadway, and relates to the technical field of roadway monitoring. The method comprises the following steps: starting a data acquisition system, calculating a rock mass elastic wave velocity attenuation rate, a support rotation angle and a corrosion rate, and standardizing overpressure and impulse data to generate a real-time curve; real-time prediction of the risk level is realized based on the LSTM neural network; and selecting parameters sensitive to the corrosion holes, establishing a development index of the corrosion holes, and generating a corrosion damage report of each monitoring unit. According to the method, a relation model between monitoring data and the corrosion damage degree is established by fusing triple triggering conditions of LSTM neural network prediction, a multi-load coupling curve and a key parameter threshold value; the mechanical response and damage development process of the roadway under the corrosion effect is simulated, the future deformation and damage trend of the roadway is predicted, and the accuracy of an analysis result is improved.

The invention belongs to the field of foundation treatment, and discloses a soil body compaction degree monitoring method and a related device, and the method comprises the steps: collecting a vibration wave signal of a vibration wheel of a road roller operating on the surface of a to-be-detected soil body; carrying out spatial domain filtering and frequency domain filtering processing to obtain a preprocessed vibration wave signal; based on the pre-processed vibration wave signal, combining a pre-constructed elastic wave velocity-density dynamic inversion model to obtain the total density of the to-be-measured soil body; the elastic wave velocity-density dynamic inversion model is deduced according to an expanded Biot fluid saturated porous medium wave equation; the expanded Biot fluid saturated porous medium wave equation is a Biot fluid saturated porous medium wave equation into which unsaturated soil phase constitutive and equivalent soil particle skeleton modulus are introduced; according to the total density of the to-be-measured soil body, the compaction degree of the to-be-measured soil body is obtained through calculation; according to the invention, high-precision monitoring of the compaction degree of the soil body is realized, continuous and real-time monitoring of the construction process of the adaptive road roller can be realized, and the monitoring efficiency and precision are both considered.

The invention discloses a multi-method cooperative detection method and system for a karst collapse hidden danger area, and relates to the technical field of geographic detection, and the method comprises the steps: laying an observation network in a target hidden danger area, respectively implementing an electric excitation sequence and a mechanical vibration excitation sequence, and collecting potential difference data and vibration waveform data; performing inversion on the potential difference data and the vibration waveform data at each acquisition moment, analyzing the phase relation and the change form of the resistivity sequence and the elastic wave speed sequence relative to the corresponding excitation time sequence, and dividing areas with different response characteristics according to the characteristic difference of the multi-physical field dynamic response mode in the space; according to the method, the multi-physical-field dynamic response mode representing the dynamic processes such as underground water seepage and particle migration can be extracted, direct depiction of the activity degree and the evolution time sequence of the dynamic processes in the hidden danger area is achieved, and the capacity of identifying the development stage of the hidden danger from physical response is improved.

The invention discloses an elastic wave tomography detection method for embankment quality, which comprises the following steps of: synchronously acquiring a source end reference signal at a vibration source of a road roller and an earth surface response signal on the surface of a detected area, and establishing a unified time reference of the source end reference signal and the earth surface response signal; and calculating a cross-correlation function of the source end reference signal and the surface response signal, and determining coarse estimation arrival time based on a peak value. And extracting a characteristic frequency component from the signal, obtaining and analyzing signal phase information, calculating the phase difference of the earth surface response signal relative to the source end reference signal at the roughly estimated time, and determining the fine time correction by using the phase difference. And correcting the roughly estimated arrival time by using the fine time correction to obtain final elastic wave arrival time, and performing inversion to generate an elastic wave velocity distribution image. According to the invention, by collecting the real source end waveform and combining the phase refinement technology, the limitation of the sampling rate on the measurement precision is broken through, and the resolution and reliability of compaction quality detection are improved.

The application discloses a method for rapidly simulating three-dimensional scattered waves in a sound wave far detection transversely isotropic stratum, and belongs to the field of seismic wave forward simulation. The application is used to solve the technical problem that it is difficult to efficiently and universally simulate three-dimensional scattered waves in single well imaging of the transversely isotropic stratum in the prior art. The application comprises the following steps: obtaining parameters required for simulation; deriving an analytical solution of a sound source far field wave under a transversely isotropic medium according to a steepest descent integral method, and obtaining an incident wave field, wherein saddle points of quasi-SV waves and quasi-P waves are solved by using a Newton-Raphson method; establishing an elastic wave velocity-stress staggered grid, introducing the incident wave field into a calculation space boundary by using a total field / scattered field technology, and performing numerical simulation on a local region containing a scatterer to obtain a near field scattered wave field; calculating a virtual source wave field based on the analytical solution; and converting the near field scattered wave field and the virtual source wave field into a scattered wave field at a position of a well receiver based on a fluid-solid coupling reciprocity theorem. The application is suitable for a transversely isotropic medium with arbitrary parameters.

The invention provides a loose sandstone displacement process digital rock core construction and elastic wave velocity simulation method, and belongs to the technical field of oil and gas geophysical exploration, and the method comprises the following steps: constructing an initial digital rock core; continuously calculating and operating water / oil saturation values of all positions of the array in a traversal mode, so as to realize establishment of digital rock cores with different water / oil saturations; on the basis of digital rock cores with different water / oil saturations, continuously calculating and operating substance types at all positions of an array by adopting a traversal mode, and realizing construction of digital rock core framework weakening in the displacement process; initial conditions and boundary conditions are established, constitutive and wave equations of the digital rock core containing the multiphase fluid are adopted, and elastic wave velocity calculation of the digital rock core is achieved. According to the method, the digital rock core in the loose sandstone multiphase fluid displacement process is constructed, the elastic wave velocity of the loose sandstone multiphase fluid displacement process is simulated through the rotary staggered grid finite difference technology, and key technical support can be provided for quantitative parameter interpretation of remaining oil distribution.