Underground rock dynamic disasters are becoming more severe due to the increasing depth of human operations underground.Underground temperature and pressure conditions contribute significantly to these disasters.There...Underground rock dynamic disasters are becoming more severe due to the increasing depth of human operations underground.Underground temperature and pressure conditions contribute significantly to these disasters.Therefore,it is important to understand the coupled thermo-mechanical(TM)behaviour of rocks for the long-term safety and maintenance of underground tunnelling and mining.Moreover,investigation of the damage,strength and failure characteristics of rocks under triaxial stress conditions is important to avoid underground rock disasters.In this study,based on Weibull distribution and Lemaitre's strain equivalent principle,a statistical coupled TM constitutive model for sandstone was established under high temperature and pressure conditions.The triaxial test results of sandstone under different temperature and pressure conditions were used to validate the model.The proposed model was in good agreement with the experimental results up to 600℃.The total TM damage was decreased with increasing temperature,while it was increased with increasing confining pressure.The model's parameters can be calculated using conventional laboratory test results.展开更多
This study aims to examine the influence of pre-existing discontinuities on the strengths of four natural rocks of different origins.A series of unconfined compression tests was performed on specimens of two types of ...This study aims to examine the influence of pre-existing discontinuities on the strengths of four natural rocks of different origins.A series of unconfined compression tests was performed on specimens of two types of sandstones,argillite and basalt that contain open and filled cracks.It was found that the presence of cracks tends to decrease the overall strength for all studied rocks;however,the magnitude of strength reduction is related to the property of rock.The larger strength decrease was observed for the relatively harder argillite and basalt,compared to the softer sandstone.It was also found that the infill material could increase the strength of rock specimens,while the obtained strength depended on the characteristics of the fill material.展开更多
基金the Bowen Basin Underground Geotechnical Society for funding this project。
文摘Underground rock dynamic disasters are becoming more severe due to the increasing depth of human operations underground.Underground temperature and pressure conditions contribute significantly to these disasters.Therefore,it is important to understand the coupled thermo-mechanical(TM)behaviour of rocks for the long-term safety and maintenance of underground tunnelling and mining.Moreover,investigation of the damage,strength and failure characteristics of rocks under triaxial stress conditions is important to avoid underground rock disasters.In this study,based on Weibull distribution and Lemaitre's strain equivalent principle,a statistical coupled TM constitutive model for sandstone was established under high temperature and pressure conditions.The triaxial test results of sandstone under different temperature and pressure conditions were used to validate the model.The proposed model was in good agreement with the experimental results up to 600℃.The total TM damage was decreased with increasing temperature,while it was increased with increasing confining pressure.The model's parameters can be calculated using conventional laboratory test results.
基金The authors would like to acknowledge Mr.Beau McDonald for his invaluable help with laboratory testing.
文摘This study aims to examine the influence of pre-existing discontinuities on the strengths of four natural rocks of different origins.A series of unconfined compression tests was performed on specimens of two types of sandstones,argillite and basalt that contain open and filled cracks.It was found that the presence of cracks tends to decrease the overall strength for all studied rocks;however,the magnitude of strength reduction is related to the property of rock.The larger strength decrease was observed for the relatively harder argillite and basalt,compared to the softer sandstone.It was also found that the infill material could increase the strength of rock specimens,while the obtained strength depended on the characteristics of the fill material.
