101 results about "Uniaxial compression" patented technology

The invention provides a coal impact tendency evaluation method which comprises the following steps: sampling a coal rock material on an engineering site, and processing the sample into a coal rock test piece with a preset size and a preset shape; carrying out a uniaxial compression experiment on the coal rock test piece, and recording a motion image of an ejection body on the coal rock test piece in the loading process of the coal rock test piece; comparing cosine similarities among the plurality of images in the moving images, and determining the image with the maximum damage degree according to the cosine similarities; analyzing gray level distribution of the image with the maximum damage degree to obtain a gray level histogram; identifying particle information of the broken particles in the image with the maximum damage degree; representing the damage degree of the coal rock material by using the particle information of the crushed particles; and evaluating the coal impact tendency by using the damage degree of the coal rock material. According to the evaluation method for the coal impact tendency disclosed by the invention, a new coal impact tendency evaluation index is provided, the research on the damage process of the coal rock material is perfected, and basic parameters are provided for subsequent early warning of damage of the coal rock material.

The invention discloses a cement stabilized macadam mechanical property analysis method based on maximum aggregate nominal particle size, and relates to the technical field of cement stabilized macadam mechanical property analysis, the method comprises the following steps: preparing skeleton dense type cement stabilized macadam test pieces with different nominal maximum particle sizes; carrying out a macroscopic mechanical test to obtain a stress-strain curve and a crushing value; establishing a three-dimensional discrete element numerical model corresponding to the test piece, performing uniaxial compression simulation, and ensuring the reliability through model verification; and based on the verified model, quantitatively analyzing the contact force distribution, the contact quantity characteristic and the microcrack evolution law from the microscopic level. According to the analysis method disclosed by the invention, a mechanism that the nominal maximum particle size improves the macroscopic performance of the material by regulating and controlling an internal force chain network and inhibiting damage accumulation is disclosed through a macro-micro combination means, and a scientific micro-mechanical basis and a quantitative analysis tool are provided for grading optimization and high-performance design of the cement stabilized macadam base.

The invention discloses a deep well rock mass instability failure time accurate forecasting and early warning system, and relates to the technical field of deep well rock mass failure early warning, and the deep well rock mass instability failure time accurate forecasting and early warning system comprises the following steps: collecting a plurality of deep well rock samples to carry out a uniaxial compression experiment, and collecting acoustic emission signals in real time based on an acoustic emission sensor to obtain original acoustic emission signal data; carrying out self-adaptive preprocessing, and carrying out data classification and integration to obtain rock sample acoustic emission parameter data; constructing an original damage forecasting model, and performing model training and verification optimization based on the rock sample acoustic emission parameter data to obtain a rock damage forecasting model; collecting an acoustic emission signal of the deep well rock mass, and predicting the instability failure time of the deep well rock mass in real time based on the rock failure forecasting model; the method is used for solving the problems that when an existing deep well rock mass damage early warning technology carries out early warning on rock mass instability damage through acoustic emission monitoring, single or few characteristic parameters are manually processed and analyzed, and the early warning reliability and timeliness are not high.

The invention discloses a roadway roof damage time prediction method and system, and belongs to the technical field of mine rock mechanics and safety engineering. Comprising the following steps: recognizing a roof rock stratum structure and lithology of each layer through drilling peeping, and drilling a representative rock sample; determining the crack initiation strength and peak strength of the rock sample through a uniaxial compression test; selecting a plurality of stress levels between the axial strain and the acoustic emission signal to carry out a creep test, synchronously monitoring the axial strain and the acoustic emission signal, and determining an accelerated creep starting moment as the damage time under the stress according to the abrupt change characteristics of the axial strain and the acoustic emission signal; establishing a stress-failure time relation model of each lithology; finally, selecting a corresponding model to predict the damage time of rocks at different layers of the roof according to the actual rock stratum structure and ground stress state of the roadway; according to the method, accurate and reliable time prediction of the progressive damage process of the roadway roof is realized.

The invention discloses an aggregate random distribution concrete PFC (Power Factor Correction) simulation method, which comprises the following steps: a model selection step: determining a parallel bonding model as a mechanical model for concrete material simulation; a cement mortar matrix generation step of generating a cement mortar matrix by using particles in a set size range in a set space range based on the model, and setting pore density, particle density and contact model parameters; a coarse aggregate random distribution simulation step: randomly covering and grouping original particles in the matrix in a grouping and range mode; a concrete numerical model construction step: determining particle classification so as to distinguish cement mortar and coarse aggregate; and a model reliability verification step: comparing indoor test results through a uniaxial compression test. According to the method, the simulation accuracy is improved, the randomness of aggregate is reduced, the model reliability is ensured, the matrix simulation refinement degree is improved, and a method is provided for concrete modeling and performance research.

An intelligent monitoring and early warning method for damage failure of a filling body beside a gob-side entry retaining roadway comprises the steps that a high-water-content material standard sample is prepared, uniaxial compression testing and acoustic emission monitoring are carried out, and mechanical property data and acoustic emission waveform signals are synchronously obtained; carrying out failure stage division based on the maximum stress value and a sliding linear fitting method, and carrying out automatic classification and labeling operation; solving variational mode decomposition key parameters through an intelligent optimization algorithm to obtain decomposed intrinsic mode components; constructing a sample data set through a data enhancement process; training to obtain a waveform-based destruction stage classification model; elastic wave signals are collected in real time, variational mode decomposition and noise reduction processing are carried out, intrinsic mode components highly related to the damage degree are obtained and serve as input data, and a classification result is output through a waveform-based damage stage classification model; and performing graded early warning. According to the method, the real-time dynamic monitoring of the damage failure of the roadside filling body can be realized, and the early warning of the damage failure of the high-water material roadside filling body can be realized.

The invention discloses a coal body compression mechanical test acoustic emission signal processing method and system, and relates to coal rock mass analysis. The method comprises the steps that under the supercritical water coupling effect condition, an acoustic emission original data set of the whole coal body uniaxial compression damage process is collected; respectively carrying out time domain processing, frequency domain conversion and spatial positioning calculation on the original data set, and outputting a time domain characteristic parameter, a frequency domain characteristic parameter set and a spatial position parameter set; and performing data fusion on the time domain characteristic parameter set, the frequency domain characteristic parameter set and the spatial position parameter set, establishing a multi-dimensional characteristic data matrix through time synchronization, and analyzing acoustic emission signal laws of different damage stages of the coal body under the supercritical water coupling effect. Aiming at the low recognition precision of the coal body damage stage under the supercritical water coupling effect, the recognition precision is improved by performing time domain processing, frequency domain conversion, spatial positioning calculation and the like on an acoustic emission original data set.

The invention discloses a non-contact uniaxial compression test infrared strain meter and a use method thereof, and belongs to the field of rock mechanics and engineering testing. The objective of the invention is to solve the prominent problems of low measurement precision, easy influence by characteristics of a test object, difficulty in comprehensively and accurately reflecting full-field strain distribution and the like of a traditional contact type strain measurement device in a uniaxial compression test. A non-contact infrared imaging measurement technology is adopted, a high-speed infrared camera is matched with a DIC algorithm, real-time mapping of full-field strain distribution is accurately achieved, transient behaviors such as crack initiation and expansion are clearly captured, strain field data and temperature field data can be synchronously obtained, measurement of the strain field data and the temperature field data are organically combined, and by means of the infrared technology and an environment control device, the measurement accuracy is improved. The device can stably work in severe environments such as high temperature and corrosivity, and is suitable for various complex samples; according to the method, the accuracy and comprehensiveness of measurement are effectively improved, the test efficiency is greatly improved, the method can be widely expanded to multiple fields of civil engineering, aerospace and the like, and powerful support is provided for research on mechanical properties of materials.

The present application belongs to the field of mechanics, and particularly relates to a method for eliminating error of a quasi-static compression mechanics experiment system. By using a constant pressure or a constant loading speed of a pressure head on a testing machine to perform quasi-static uniaxial compression on a test piece at room temperature, and taking two test pieces of different heights, the relationship between the system stiffness, the force and deformation of the system pressure head can be obtained, so as to obtain two corresponding force-time curves and displacement-time curves. By combining the two equations and eliminating the unknown Young's modulus E, the stiffness coefficient of the test system can be obtained, and the displacement-time curve of the pressure head can be obtained. Subsequently, the Young's modulus E can be inversely solved. The present application corrects the error of the mechanics experiment by defining the system stiffness coefficient, so as to realize a higher precision of the Young's modulus E and improve the accuracy of the quasi-static mechanics experiment.

The application provides a particle crushing strength prediction method and system considering pore parameters, relates to the technical field of geotechnical particle material mechanics, and aims at the problem that the prior art depends on a single parameter, lacks analysis and correlation analysis of the role of the single parameter, the model is single, and prediction accuracy and generalization ability are low.The method uses 3D printing to obtain particles with different particle sizes and pores, obtains the internal microstructure of the particles through micro-CT scanning, extracts pore characteristic parameters, considers multi-dimensional pore parameter characteristics, performs a uniaxial compression crushing experiment, quantifies the relationship between the multi-dimensional pore characteristic parameters and the particle crushing strength, calculates the actual particle crushing strength, establishes a PSO-SVR particle crushing strength prediction model, corrects the crushing strength predicted by the model according to the actual particle crushing strength and based on a calibration factor introduced based on a Weibull model.The application solves the problems in the prior art and improves the prediction accuracy and generalization ability of the model.

The invention provides a portable multifunctional rock mechanics testing machine and method, and relates to the technical field of rock mechanics tests. According to the portable multifunctional rock mechanics testing machine, an expansion test assembly, a uniaxial compression test assembly, a point load test assembly, an indentation test assembly or a compression-shear test assembly are selectively arranged between a telescopic rod of a loading oil cylinder and / or a force transducer. The testing machine disclosed by the invention is simple and light in structure, and can be conveniently carried to an engineering site to carry out a rock mechanical test, so that on-site loading and data acquisition of a rock sample are realized; the tester can accurately control stress and strain conditions and can realize stable and uniform loading and unloading on site so as to obtain a reliable test result; the testing machine integrates multifunctional testing, and different testing assemblies are matched with an expansion test, a uniaxial compression test, a point load test, an indentation test or a compression-shear test, so that multi-parameter testing is realized aiming at different rock sample conditions.

The application discloses a coal body compression mechanics test acoustic emission signal processing method and system, relates to coal and rock mass analysis, and comprises the following steps: collecting acoustic emission original data sets of the whole process of coal body uniaxial compression destruction under the condition of supercritical water coupling; respectively performing time domain processing, frequency domain conversion and space positioning calculation on the original data sets, outputting time domain characteristic parameters, a frequency domain characteristic parameter set and a space position parameter set; fusing the time domain characteristic parameter set, the frequency domain characteristic parameter set and the space position parameter set, establishing a multi-dimensional characteristic data matrix through time synchronization, and analyzing acoustic emission signal rules of different destruction stages of the coal body under the condition of supercritical water coupling. The application improves the recognition accuracy by performing time domain processing, frequency domain conversion and space positioning calculation on the acoustic emission original data set, and solves the problem of low recognition accuracy of the coal body destruction stage under the condition of supercritical water coupling.

This paper provides a method, apparatus, device, and storage medium for automatically acquiring rock mechanical parameters. The method includes: reading stress-strain data obtained from uniaxial compression experiments on rocks; interpolating the stress-strain data to form a stress-strain curve; dynamically extending the stress-strain curve towards both ends, starting from a target point, until the goodness of fit of the regression line formed by the current extension is lower than a set threshold; segmenting the stress-strain curve using the stress peak point, strain peak point, and endpoint of the regression line as segmentation points; calling a first rock mechanical parameter calculation module to process the stress-strain curve and obtain a first type of rock mechanical parameters; and calling a second rock mechanical parameter calculation module to process the segmented stress-strain curve and obtain a second type of rock mechanical parameters; and merging the two types and outputting the results. The embodiments described in this paper can improve the efficiency and accuracy of acquiring rock mechanical parameters.

The application discloses a kind of early warning methods of easy argillization rock instability mutation, including making rock sample, respectively on rock sample under the condition of uniaxial compression acoustic emission test, and obtain the displacement, load and acoustic emission parameter numerical value of each rock sample;Calculate and analyze the mutation characteristics of the evolution of elastic strain energy curve of easy argillization rock;Construct the early warning model of elastic strain energy strain sequence of easy argillization rock instability mutation, when the simultaneous difference set equation Δ>0 indicates that easy argillization rock is in stable state, Δ<0 when easy argillization rock is in unstable state, Δ=0 when easy argillization rock is in critical state.The method of the application can comprehensively, quickly and accurately predict the instability mutation failure of easy argillization rock, and provide scientific reference basis for early warning prevention and treatment of rock instability mutation of mine exploitation.

The application discloses a cement stabilized macadam mechanical property analysis method based on maximum aggregate nominal particle size, relates to the technical field of cement stabilized macadam mechanical property analysis, and comprises the following steps: preparing skeleton dense type cement stabilized macadam test pieces with different nominal maximum particle sizes; performing macroscopic mechanical test to obtain stress-strain curves and crushing values; establishing a three-dimensional discrete element numerical model corresponding to the test pieces and performing uniaxial compression simulation, and verifying the model to ensure the reliability of the model; and based on the verified model, quantitatively analyzing contact force distribution, contact quantity characteristics and microcrack evolution law from a microcosmic aspect. According to the analysis method, the macroscopic performance of the material is improved by regulating the internal force chain network and inhibiting damage accumulation through the nominal maximum particle size, and the analysis method discloses the mechanism that the nominal maximum particle size improves the macroscopic performance of the material by regulating the internal force chain network and inhibiting damage accumulation, and provides a scientific microcosmic mechanical basis and a quantitative analysis tool for gradation optimization and high-performance design of the cement stabilized macadam base.

The application provides a kind of magnesium slag based filling body damage constitutive model construction method based on energy dissipation, and relates to filling body damage analysis technical field.The method first makes magnesium slag based filling body test piece under different magnesium slag powder grinding time conditions, and obtains the stress-strain curve of each test piece by test, analyzes the energy evolution curve of each test piece;Then the damage dissipation energy is introduced into the energy balance equation of filling body, and the damage variable related to damage dissipation energy is obtained;Then compare the damage constitutive model, construct the energy modified damage constitutive model of magnesium slag based filling body considering the compaction stage and residual strength;Finally, verify the effectiveness of the model.The energy modified damage constitutive model constructed by the application is reasonable and effective, which can well describe the damage evolution process of magnesium slag based filling body under uniaxial compression, realize quick and accurate magnesium slag based filling body damage analysis, and provide scientific reference for the safety of mine filling mining engineering.

The application provides an acidification fracturing fracture pressure prediction method considering rock mechanics property acid erosion degradation. The method comprises the following steps: subjecting the acid-eroded rock sample to uniaxial compression experiment and splitting experiment respectively; obtaining an acid-eroded rock mechanics parameter-acid erosion temperature-acid erosion time model according to the uniaxial compression experiment data and the splitting experiment data; integrating the acid-eroded rock mechanics parameter-acid erosion temperature-acid erosion time model into a conventional formation fracture pressure model to obtain an acidification fracturing fracture pressure prediction model considering rock mechanics property acid erosion degradation. The method comprehensively considers the influence of formation temperature and acid erosion time on reservoir mechanics property, can predict the acidification fracturing fracture pressure, and can provide a theoretical basis for field engineering parameter design.

The application provides a phanerocrystalline intrusive rock blasting simulation method and device, comprising the following steps: constructing an initial rock crystal sample uniaxial compression model according to the mesoscopic physical parameters of a target phanerocrystalline intrusive rock; generating a cohesive force unit on the contact interface between the grains in the uniaxial compression model to obtain a target rock crystal sample uniaxial compression model; performing a uniaxial compression simulation test on the target rock crystal sample uniaxial compression model, obtaining test simulation data, correcting parameters through a back analysis method, obtaining target material parameters of the target phanerocrystalline rock, and constructing a rock crystal medium blasting construction FDEM model; and performing blasting simulation on the target phanerocrystalline intrusive rock according to the rock crystal medium blasting construction FDEM model and blasting parameters. Therefore, the finite-discrete coupling blasting simulation method can not only reduce the cost and time consumption, but also quantitatively represent the dynamic response law and damage mechanism of the rock mass in the blasting process.

The invention provides a quasi-static uniaxial compression small experiment clamp for a fragile material in an active triaxial confining pressure environment, and belongs to the technical field of material mechanics testing, the quasi-static uniaxial compression small experiment clamp comprises an experiment machine pressure plate, a pressurization cabin body, an end cover and a loading combination, the pressurization cabin body is of a hollow cylindrical structure, the loading combination is installed in the pressurization cabin body, and the end cover is connected with the loading combination. The upper part of the loading combination is connected with an end cover, and the end cover is screwed and sealed in the pressurizing cabin body through threads; the loading assembly comprises a loading ejector rod, an upper loading rod and a lower loading rod, a to-be-tested piece is located between the upper loading rod and the lower loading rod, the upper loading rod is connected with the loading ejector rod, the loading ejector rod penetrates through the end cover to be in contact with the testing machine pressing disc, and the lower loading rod is connected with the loading rod fixing disc. The test fixture has the advantages of high adaptability, high precision, reliable sealing, convenience in operation and controllable cost, and an efficient and reliable test fixture is provided for multi-axial stress performance characterization of small brittle materials in the field of material mechanical property characterization.

The invention provides a glass coarse crushing simulation method based on discrete elements, and belongs to the technical field of glass material processing.The method comprises the steps that firstly, a stacking angle simulation model is built by means of discrete element software on the basis of actual material physical property parameters, and contact parameters between particles are obtained; then, parameters of a BPM (Bonded Particle Model) are defined by comparing a physical experiment with a simulation uniaxial compression result, and finally, the efficient and high-precision DEM simulation method for glass coarse crushing is established according to all the obtained parameters. The constructed model can truly reproduce the whole crushing process under different materials, equipment structures and process parameters, and provides key technical support for deeply understanding the mechanism, optimizing the process, improving the equipment performance and reducing the research and development cost.

The application discloses a kind of mesoscopic parameter multistage calibration method suitable for discrete element linear contact bonding model.The method follows the three-level progressive system of "single component-mixture-structure", and adopts the decoupling strategy of "stiffness first, strength later".Firstly, based on the uniaxial compression simulation of single component and mixture, the mapping relationship between macro modulus and mesoscopic normal stiffness is established to calibrate the stiffness parameter, and the parameter precision is further improved by structure load model fine tuning;then, based on the splitting simulation of single component and mixture, the mapping relationship between macro strength and mesoscopic tensile strength is established to calibrate the strength parameter.The method solves the problem of low efficiency and unclear physical meaning of traditional trial-and-error method, significantly improves the efficiency, accuracy and physical reasonableness of discrete element mesoscopic parameter calibration.

The invention relates to a method for constructing a rock salt nonlinear damage creep constitutive model considering a temperature effect. The method comprises the following steps: constructing an element combination model formed by connecting an elastomer, a nonlinear viscous body and a generalized Kelvin body in series as a basic framework of the rock salt nonlinear damage creep constitutive model considering the temperature effect; introducing a damage variable related to time and temperature; establishing a constitutive equation of the nonlinear viscous body of the salt rock; based on the constitutive equation of the salt rock nonlinear viscous body, deducing a total creep strain expression of a salt rock nonlinear damage creep constitutive model considering the temperature effect in a one-dimensional stress state; and carrying out uniaxial compression creep tests on the salt rock sample at different temperatures by adopting a graded loading mode to obtain strain-time data and a corresponding creep curve of the salt rock sample at the corresponding temperature, and carrying out inversion to determine model parameters in the total creep strain expression. The invention also provides a long-term deformation prediction method of the salt-cavern underground gas storage cavern structure.

This invention relates to a dual evaluation method for fracturing performance of shale reservoirs based on a cohesion-friction-bedding coupling model. It includes: preparing shale samples with different bedding angles; conducting Brazilian splitting experiments, uniaxial compression experiments, and triaxial compression experiments to obtain time-load curves and stress-strain curves for shale at different bedding angles; and constructing a shale brittleness index under uniaxial stress. B un Determine the degradation coefficient of shale brittleness due to confining pressure. B wc Constructing the brittleness index of shale under triaxial stress conditions B tr Shale brittleness index under triaxial stress conditions B tr This invention combines well logging data to predict the distribution of rock brittleness across the entire block and well section, clarifying reservoir compressibility, and integrates with geological modeling software to predict fracture morphology and fracturing effectiveness. This invention solves the problems of inconsistent rock brittleness assessment results and the difficulty in combining them with geophysical data for application in anisotropic shale, which negatively impacts shale reservoir fracturing design and fracturing effectiveness evaluation.

The invention discloses a coal rock unilateral free surface plane strain compression test device and method, and relates to the technical field of rock mechanics and mine engineering.The coal rock unilateral free surface plane strain compression test device comprises a main base and supporting legs, a limiting column is fixedly installed on the main base, a pressing plate body driven by a hydraulic push rod is arranged on the limiting column, and a linear guide rail is further installed on the main base; a linear guide rail is arranged on the main base, the linear guide rail is provided with a displacement seat driven by a driving mechanism, a lateral baffle is further connected to the main base in a sliding mode, an observation frame driven by an adjusting mechanism is further arranged on the main base, and an experiment area used for containing a coal rock mass is jointly formed between the pressing plate body and the lateral baffle. During use, the hydraulic push rod drives the pressing plate main body to vertically apply pressure to simulate uniaxial compression, and meanwhile, the displacement seat is matched to drive the lateral baffles to extrude the two sides of a sample to simulate a direct shear test; the two stress states are combined to accurately simulate the actual stress condition of the coal and rock mass under the condition of a single-side free surface.

The invention discloses a particle coating elastic modulus rapid calibration method based on a fractal continuum theory, and the method comprises the steps: firstly constructing free accumulation particle coatings with different heights, and recording the height, particle size, residual dimension in the height direction and section fractal dimension perpendicular to the height direction of the particle coatings; constructing a relative coating height parameter, and establishing a correlation between the relative coating height and the remainder dimension as well as the section fractal dimension; discrete element simulation of the uniaxial compression process is carried out on each structural coating, and the compression amount and the compression force change of the coating in the compression process are recorded; constructing a relational expression of the compression amount and the compression force of the particle coating, wherein the relational expression relates to a remainder dimension, a section fractal dimension and a harmonic index to be fitted; fitting a harmonic index p based on the simulation data; based on the relational expression and the harmonic index, the coating compression amount and the compression force reconstruction value are recorded, and based on the constitutive relation of the uniaxial compression process of the continuum, inversion calibration is carried out on the coating elasticity modulus, and rapid calibration of the elasticity modulus of the whole coating growth process can be achieved.

The invention relates to a method and a system for measuring strain of an ice sample in a uniaxial compression test process by using a crystal texture digital image. The method comprises the following steps: preparing the ice sample: preparing the ice sample according to a predetermined direction of the uniaxial compression test; polarized light imaging arrangement: placing the ice sample between a chassis and a pressure plate of a uniaxial compression testing machine; a cold light source with adjustable brightness is arranged behind the ice sample, and a polaroid is arranged between the cold light source and the ice sample; arranging a high-speed camera in front of the ice sample and installing a polarized lens to receive polarized light passing through the ice sample; adjusting image quality: enabling the length direction of the ice sample to be along the loading direction of a tester and the thickness direction to be along the light path direction of polarized light; uniaxial compression test and synchronous acquisition; calculating a strain field: calculating a strain field and a deformation field of the surface of the ice sample according to a digital image correlation method based on the polarized light grayscale images of the ice sample at adjacent moments; and identifying crack propagation.

The method for evaluating the fracture mechanics performance of the water-soaked brittle solid material of the present application comprises the following steps: 1. A group of cuboid brittle solid material samples are prepared, and the samples are immersed in water. After the immersion is completed, the samples with different immersion times are selected for weighing, and then the samples with different water contents are selected; 2. The samples with different water contents in step 1 are selected, and the relationship curve between the uniaxial compression stress and strain of the brittle solid material samples and the initial density of the micro-defects of the samples under different water contents are measured; 3. The samples with different water contents in step 1 are selected, and the sliding friction coefficients of the brittle solid material samples with different water contents are determined; 4. The brittle solid samples containing cracks are prepared, and the fracture toughness of the brittle solid material with different water contents is measured; and 5. Based on the above steps, the fracture strength of the brittle solid material samples under the action of different water contents after being soaked in water is determined.

The invention provides an embedded stress sensor sensitivity correction method considering a concrete elastic-plastic stage, and the method comprises the steps: obtaining the external calibration sensitivity of a sensor, and obtaining the external calibration sensitivity based on the calibration relation between an output signal of the sensor in a uniaxial compression state and the strain of the sensor, the elastic modulus of the sensor is a known constant value; pre-burying the calibrated sensor in concrete, synchronously collecting a monitoring charge signal output by the sensor when a load is applied, and measuring the reference strain of the concrete at the pre-buried position of the sensor; determining a sensor conversion strain according to the monitoring charge signal and the external calibration sensitivity; determining a correction factor according to the ratio of the sensor conversion strain to the reference strain; according to the monitoring charge signal, the external calibration sensitivity and the correction factor, the real strain of the concrete is obtained, and then the real strain is converted into the internal stress of the concrete based on the concrete stress-strain constitutive relation.

This invention discloses a method for monitoring the surface deformation evolution process of rock undergoing uniaxial compression creep failure, belonging to the field of geotechnical and rock mechanics testing technology. The steps are as follows: Step 1: Set up a test platform, which includes a speckle spraying system, an imaging and illumination module, a test device, and a host computer; Step 2: Fabricate rock test specimens and arrange the imaging and illumination module; Step 3: Obtain the compressive strength and set the graded loading levels; Step 4: Form a white base layer and black speckles on the surface of the rock specimen, meeting the requirements; Step 5: Conduct a uniaxial graded loading creep test on the rock specimen and acquire image data; Step 6: Process the image data to obtain the strain field evolution process on the specimen surface. This invention uses the above method to record the changes of the white base layer and black speckles during compression using an imaging device, thereby obtaining the deformation creep failure characteristics and evolution law of the rock surface.

The invention provides a thermal-mechanical coupling device based on a uniaxial compression experiment system and a test method. The device comprises an automatic temperature console, a high-low temperature heat conduction system and a high-low temperature separation experiment box. The invention also discloses a test method, which comprises the following steps of: dividing an experiment area of the uniaxial tester into two spaces with lower heat conduction by the high and low temperature separation experiment box, and feeding back sensor information such as temperature, pressure and flow to the automatic temperature control console in real time for processing; the heating and cooling rate and the target temperature are adjusted through the high and low temperature heat conduction system, so that different high temperature difference spaces are realized, the heat conduction time is controlled by means of a thermocouple and the like, the temperature difference is formed inside the test piece under heat transfer of the high and low temperature spaces, and finally the uniaxial compression test is performed. The device has the experimental advantages of sensitive induction, automatic temperature control, adjustable rate, large temperature difference and the like, and can meet the engineering and scientific research requirements of rock uniaxial compression under extremely high temperature difference.