Reliable evaluation of in-situ stress is an important issue for the analysis and design of underground excavations, particularly for evaluating the stability of underground structures to prevent failure or collapse. A...Reliable evaluation of in-situ stress is an important issue for the analysis and design of underground excavations, particularly for evaluating the stability of underground structures to prevent failure or collapse. A low-cost and reliable technique for the estimation of the full stress tensor based on acoustic emission (the Kaiser effect) has been developed at the WA School of Mines over last five years. This paper presents the results for a feasibility study where four AE measurements for an Australian mine have been carried out. The results are compared well with those obtained by the conventional hollow inclusion over-coring method (HI Ceil). The advantages of the AE technique are that it is relatively cheap, non-time consuming and is applicable to in-situ stress measurements at depth in remote regions.展开更多
Excavation damage under high in situ stress depends largely upon the potential block size associated with any violent ejection.The size and shape of the dynamic instability are largely controlled by the location,orien...Excavation damage under high in situ stress depends largely upon the potential block size associated with any violent ejection.The size and shape of the dynamic instability are largely controlled by the location,orientation and extent of the pre-existing geological discontinuities.A new methodology is presented in which the rock mass demand can be expressed in terms of the mass in tonnes of unstable rock that is ejected per unit area of the excavation surface where failure occurs.A probabilistic approach has been implemented to estimate the potential rock mass instabilities and their associated static and dynamic demands.The new methodology considers that the strain energy released by the rock mass during violent stress-driven failure is largely converted into kinetic energy of ejection for blocks.The estimated dynamic demand has been favourably compared with observations of rock mass damage in a number of underground excavations.展开更多
文摘Reliable evaluation of in-situ stress is an important issue for the analysis and design of underground excavations, particularly for evaluating the stability of underground structures to prevent failure or collapse. A low-cost and reliable technique for the estimation of the full stress tensor based on acoustic emission (the Kaiser effect) has been developed at the WA School of Mines over last five years. This paper presents the results for a feasibility study where four AE measurements for an Australian mine have been carried out. The results are compared well with those obtained by the conventional hollow inclusion over-coring method (HI Ceil). The advantages of the AE technique are that it is relatively cheap, non-time consuming and is applicable to in-situ stress measurements at depth in remote regions.
基金financial assistance and support provided over many years by various organisations including CODELCO Chile, CRC Mining, Mining3, MMG, DSI and Geobrugg
文摘Excavation damage under high in situ stress depends largely upon the potential block size associated with any violent ejection.The size and shape of the dynamic instability are largely controlled by the location,orientation and extent of the pre-existing geological discontinuities.A new methodology is presented in which the rock mass demand can be expressed in terms of the mass in tonnes of unstable rock that is ejected per unit area of the excavation surface where failure occurs.A probabilistic approach has been implemented to estimate the potential rock mass instabilities and their associated static and dynamic demands.The new methodology considers that the strain energy released by the rock mass during violent stress-driven failure is largely converted into kinetic energy of ejection for blocks.The estimated dynamic demand has been favourably compared with observations of rock mass damage in a number of underground excavations.
