Stress measurement plays a crucial role in geomechanics and rock engineering,especially for the design and construction of large-scale rock projects.This paper presents a novel method,based on the traditional stress r...Stress measurement plays a crucial role in geomechanics and rock engineering,especially for the design and construction of large-scale rock projects.This paper presents a novel method,based on the traditional stress relief approach,for indirectly measuring rock stress using optical techniques.The proposed method allows for the acquisition of full-field strain evolution on the borehole’s inner wall before and after disturbance,facilitating the determination of three-dimensional(3D)stress information at multiple points within a single borehole.The study focuses on presenting the method’s theoretical framework,laboratory validation results,and equipment design conception.The theoretical framework comprises three key components:the optical imaging method of the borehole wall,the digital image correlation(DIC)method,and the stress calculation procedure.Laboratory validation tests investigate strain field distribution on the borehole wall under varying stress conditions,with stress results derived from DIC strain data.Remarkably,the optical method demonstrates better measurement accuracy during the unloading stage compared to conventional strain gauge methods.At relatively high stress levels,the optical method demonstrates a relative error of less than 7%and an absolute error within 0.5 MPa.Furthermore,a comparative analysis between the optical method and the conventional contact resistance strain gauge method highlights the optical method’s enhanced accuracy and stability,particularly during the unloading stage.The proposed optical stress measurement device represents a pioneering effort in the application of DIC technology to rock engineering,highlighting its potential to advance stress measurement techniques in the field.展开更多
A digital modeling system method is put forward for modeling constitutive relation of geomaterial including digital image subsystem for deformation measurement, numerical modeling subsystem and numerical simulation su...A digital modeling system method is put forward for modeling constitutive relation of geomaterial including digital image subsystem for deformation measurement, numerical modeling subsystem and numerical simulation subsystem. A non-contact measurement method based on digital image processing is introduced to improve measurement of specimen deformation. Based on the method, a series of conventional tri-axial compression tests under diverse stress paths are done. Then an elasto-plastic constitutive model of soil is acquired through the numerical method of modeling constitutive law for geomaterial. Two examples of specimen deformation and ground subsidence are presented and discussed. It indicated that this method can rationally simulate the stress-strain relationship of soil, which reflects the effect of stress path on soil stress-strain relationship.展开更多
It is discussed features and tbe producing mechanism of buried geological information in geological, geophysical and remote sensing data in Huaibei coal field, and studied the methods extracting buried tectonic and ig...It is discussed features and tbe producing mechanism of buried geological information in geological, geophysical and remote sensing data in Huaibei coal field, and studied the methods extracting buried tectonic and igneous rock information from various geologicaI data using digital image processing techoiques.展开更多
基金funding support from the National Natural Science Foundation of China(Grant Nos.52125903 and 52209149).
文摘Stress measurement plays a crucial role in geomechanics and rock engineering,especially for the design and construction of large-scale rock projects.This paper presents a novel method,based on the traditional stress relief approach,for indirectly measuring rock stress using optical techniques.The proposed method allows for the acquisition of full-field strain evolution on the borehole’s inner wall before and after disturbance,facilitating the determination of three-dimensional(3D)stress information at multiple points within a single borehole.The study focuses on presenting the method’s theoretical framework,laboratory validation results,and equipment design conception.The theoretical framework comprises three key components:the optical imaging method of the borehole wall,the digital image correlation(DIC)method,and the stress calculation procedure.Laboratory validation tests investigate strain field distribution on the borehole wall under varying stress conditions,with stress results derived from DIC strain data.Remarkably,the optical method demonstrates better measurement accuracy during the unloading stage compared to conventional strain gauge methods.At relatively high stress levels,the optical method demonstrates a relative error of less than 7%and an absolute error within 0.5 MPa.Furthermore,a comparative analysis between the optical method and the conventional contact resistance strain gauge method highlights the optical method’s enhanced accuracy and stability,particularly during the unloading stage.The proposed optical stress measurement device represents a pioneering effort in the application of DIC technology to rock engineering,highlighting its potential to advance stress measurement techniques in the field.
文摘A digital modeling system method is put forward for modeling constitutive relation of geomaterial including digital image subsystem for deformation measurement, numerical modeling subsystem and numerical simulation subsystem. A non-contact measurement method based on digital image processing is introduced to improve measurement of specimen deformation. Based on the method, a series of conventional tri-axial compression tests under diverse stress paths are done. Then an elasto-plastic constitutive model of soil is acquired through the numerical method of modeling constitutive law for geomaterial. Two examples of specimen deformation and ground subsidence are presented and discussed. It indicated that this method can rationally simulate the stress-strain relationship of soil, which reflects the effect of stress path on soil stress-strain relationship.
文摘It is discussed features and tbe producing mechanism of buried geological information in geological, geophysical and remote sensing data in Huaibei coal field, and studied the methods extracting buried tectonic and igneous rock information from various geologicaI data using digital image processing techoiques.
