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Probabilistic estimate of rock mass static and dynamic demands for underground excavation stabilisation

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第3期11卷 481-493页

作者： Ernesto Villaescusa Alan Thompson Christopher Windsor Western Australia School of Mines Curtin UniversityLocked Bag 30KalgoorlieWA 6433Australia Alan Thompson Geotechnology pty.ltd. 40B Windich StreetEsperanceWA 6450Australia

Excavation damage under high in situ stress depends largely upon the potential block size associated with any violent *** 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 *** 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 *** estimated dynamic demand has been favourably compared with observations of rock mass damage in a number of underground excavations.

关键词： Geological structures Probabilistic design Underground excavations High stresses Dynamic and static demands Deep mining

Development and Demonstration of Australian First Working Sodium Guide Star Laser

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Optics and Photonics Journal 2022年第4期12卷 88-100页

作者： Yue Gao Yanjie Wang Amy Chan Ben Greene EOS Defence Systems pty.ltd. Canberra Australia

The Australian first working sodium guide star laser system has been designed and developed for various astronomical and space-related applications. A completely diode-pumped pulsed system was developed initially followed by a largely fiber-based continuous wave (CW) system operating at 589 nm achieved through a unique wavelength conversion scheme by combining 1342 and 1050 nm through a sum frequency generation process. For the CW system, single-mode laser beams at both 1342 and 1050 nm are achieved from fiber-based seed oscillators and fiber amplifiers. The output power of ~25 W at 1342 nm is achieved from a single frequency fiber Raman amplifier. Output power up to 70 W at 1050 nm is achieved from a Yb-doped fiber pre-amplifier followed by a Yb-doped fiber power amplifier. For the sum frequency generation process, optimum focusing parameters are evaluated and determined. The CW system has generated more than 20 W output power at 589 nm, a circularly polarised beam with a good beam quality, spectral linewidth ≤ 2 MHz, and the laser output locked on the sodium D2 line at 589.159 nm. The system has been successfully demonstrated at EOS Space Research Centre, Mt Stromlo, Canberra, and become the Australian first working sodium guide star laser system.

关键词： Fiber Laser Continuous Wave Laser Pulsed Laser Diode Pump Solid State Sum Frequency Generation Adaptive Optics Sodium Laser Guide Star

Design and Construction of GreenWAVE Energy Converter for Shallow Waters off South Australia

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Journal of Civil Engineering and Architecture 2015年第10期9卷 1179-1184页

作者： Leigh D. Appleyard ACOR Consultants pty.ltd. Sydney 2000 Australia

Compared with more well-known renewable energy sources, such as wind and solar, the wave energy industry is relatively new. This paper describes the structural design and construction of the oscillating water column ＂greenWAVE Energy Converter＂ which was constructed during 2013 and was planned to be deployed in shallow water off the South Australian coast in 2014. Rated initially at 1 MW, the greenWAVE unit will be dedicated to electricity production, although an option is available to produce desalinated seawater. The unit base is constructed from reinforced concrete designed to international maritime codes, and the unit will be founded in approximately 10-15 m of water. The upper portion of the device extends above sea level, housing the airwave turbine and electrical control systems.

关键词： Wave energy oscillating water column design wave.

Cosmetic Applications of Regenerative Medicine—A New Approach to the Reduction of Neck Lines

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Open Journal of Regenerative Medicine 2020年第2期9卷 36-42页

作者： E. Russell Vickers Haitao Wen Clinical Stem Cells pty.ltd. Sydney Australia

Combining different areas of regenerative medicine is considered the new standard for comprehensive tissue and organ regeneration. This approach can be further applied to cosmetic issues such as deep neck lines. This case report utilized techniques of autologous stem cell therapy and epigenetic tissue environment modulation with externally applied polyphenols and tissue penetration agents. The results showed a remarkable cosmetic improvement with a significant reduction of neck lines in a patient where employment and psychological issues were developing from the original problem. The regenerative medicine protocol was safe, efficient in disposable materials, portable benchtop equipment and surgical operating time. The patient had an excellent outcome for this difficult to treat cosmetic problem.

关键词： Regenerative Medicine Cosmetic Medicine Autologous Stem Cells Polyphenols Psychology

Analysis of the microstructure of superconducting YBCO foams by means of AFM and EBSD

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Journal of Advanced Ceramics 2014年第4期3卷 317-325页

作者： Michael Rudolf KOBLISCHKA Anjela KOBLISCHKA-VENEVA E.S.REDDY Gregor J.SCHMITZ Institute of Experimental Physics Saarland UniversityP.O.Box 151150D-66041 SaarbrückenGermany ACCESS Intzestrasse 552072 AachenGermany Nanonouvelle pty.ltd. Marcoola QLD 4564Australia

YBa_(2)Cu_(3)O_(y)(YBCO)foam samples show an open,porous foam structure,which may have benefits for many applications of high-Tc *** the basic material of these foams is a pseudo-single crystalline material with the directional growth initiated by a seed crystal similar to standard melt-textured samples,the texture of YBCO is a very important ***,we analysed the local texture and grain orientation of the individual struts forming the foam by means of atomic force microscopy(AFM)and electron backscatter diffraction(EBSD).Due to the processing route starting with Y_(2)BaCuO_(5)(211),a two-phase analysis must be performed,so a high surface quality is necessary to enable an automated EBSD *** quality Kikuchi patterns were obtained from both the YBCO and 211 *** found an inhomogeneous distribution of the residual 211 particles,which are mainly randomly oriented and have sizes ranging between 200 nm and 15μ*** contrast to this,the YBCO matrix shows a dominating orientation with cracks with a typical distance of 1-10μ***,the analysis of strut cross-sections reveals that the entire strut is converted to the YBCO phase.

关键词： high-Tc superconductors foam microstructure atomic force microscopy(AFM) electron backscatter diffraction(EBSD) orientation

Experimental Study on Improvement Effects of Completely Weathered Phyllite Using Red Clay and Cement for High-Speed Railway Embankments

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Journal of Renewable Materials 2022年第5期10卷 1287-1305页

作者： Xiushao Zhao Jianglong Rao Qijing Yang Yu Rong Zhitao Fu Zhiyao Wang Zixi Chen Engineering Research&Development Centre for Underground Technology of Jiangxi Province East China Jiaotong UniversityNanchangChina Arcadis Australia Pacific pty.ltd. SydneyAustralia School of Qilu Transportation Shandong UniversityJinanChina

Completely weathered phyllite(CWP)has the characteristics of difficult compaction,low shear strength after compaction and large settlement after *** traditional improvement method using a single agent of red clay or cement for CWP satisfies the subgrade requirements for ordinary railway,but cannot meet the requirements of immediate strength and long-term post-construction settlement of high-speed railway at the same time.A series of experimental investigations were undertaken for the blended CWP soils,with three additives *** first additive was red clay,the second was cement and the third was a combination of both red clay and cement at various *** of consolidation test and shear strength test carried out for the treated CWP soils show that:1)The effect of cement on improving the compression modulus of CWP is much better than that of red clay;2)The settlement of an embankment of 10 m high formed by blended soil of CWP with 3%cement can be controlled within 15 mm,while the settlement will be 25.15 mm for the same embankment of blended soil of CWP with 40%red clay;3)The shear strength and ultimate bearing capacity of CWP improved by red clay are much better than those of 5%cement;4)The ultimate bearing capacity of CWP improved by 40%red clay is 3.42 times of that by 3%cement and 2.95 times by 5%***,the bearing capacity of CWP when improved by red clay can meet railway subgrade requirements immediately after compaction,while cement improved CWP needs a curing time of 1 day or *** is an impediment to rapid construction *** improvement mechanism of red clay is mainly filling effect and grading improvement effect,while the improvement mechanism of cement is mainly hardening reaction,which produces high strength material to *** is found that 40%red clay and 3%cement treated CWP,which is considered to be optimum,can meet the subgrade requirements of both immediate bearing capacity and long-term post-constru

关键词： Completely weathered phyllite(CWP) red clay cement content immediate strength post-construction settlement high-speed railway

The Deep Structure Feature of the Sichuan Basin and Adjacent Orogens

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Acta Geologica Sinica(English Edition) 2015年第4期89卷 1153-1164页

作者： XIONG Xiaosong GAO Rui GUO Lianghui WANG Haiyan JIANG Zhuwei State Key Laboratory of Continental Tectonics and Dynamics Key Laboratory of Earthprobe and GeodynamicsMLRInstitute of GeologyChinese Academy of Geological Sciences School of Geophysics and Information Technology China University of Geosciences McKay Brook Resources pty.ltd.

The basin-mountain system in the Sichuan Basin （SCB） reflects the main tectonic activity and the orogenic denudation in this region. The seismic probing work reveals the deep structure of the basin-mountain system. The seismic work was re-sampled to the Moho depth and the sedimentary thickness as well as the P-wave velocity=depth function to analyze the deep structure of the SCB and adjacent orogens. The results show two deposit centers in the SCB： the Deyang area in the west and the Nanchuan area in the east and depression uplift exists in the southwestern part of the SCB; the Moho shallowers gradually from the west to east （ca. 62-36 km deep）,the South-North seismic belt （SNSB） is very distinctive： the Moho depth is much shallower （〈 50 km）to the east of the SNSB, whereas it is much deeper（〉50 kin）to the west of the SNSB, suggesting that the SNSB rather than the Longmen Shan tectonic belt is a main Moho transition belt; the topography and the top interface of the basement have the same undulation trend when the sedimentary thickness and the Moho depth have a mirror relationship; the low velocity zone developed in the Kangdian thrust and fold belt and Songpan-Garze belt implied a soft, weak and thick crust there showing tectonic activity in these areas.

关键词： Sichuan basin basin-range contact zone deep structure top interface of basement Mohodepth

Risk assessment and management in underground rock engineering——an overview

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Journal of Rock Mechanics and Geotechnical Engineering 2012年第3期4卷 193-204页

作者： Edwin T Brown Golder Associates pty.ltd. Brisbane Queensland 4064 Australia

This paper attempts to provide an overview of risk assessment and management practice in underground rock engineering based on a review of the international literature and some personal experience. It is noted that the terminologies used in risk assessment and management studies may vary from country to country. Probabilistic risk analysis is probably the most widely-used approach to risk assessment in rock engineering and in geotechnical engineering more broadly. It is concluded that great potential exists to augment the existing probabilistic methods by the use of Bayesian networks and decision analysis techniques to allow reasoning under uncertainty and to update probabilities, material properties and analyses as further data become available throughout the various stages of a project. Examples are given of the use of these methods in underground excavation engineering in China and elsewhere, and opportunities for their further application are identified.

关键词： Bayesian networks probabilistic risk analysis risk analysis risk management underground rock engineering

Utilising the scientific method to demonstrate that slender beam/column behaviour is the dominant behavioural mechanism leading to roof/rib failure

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International Journal of Mining Science and Technology 2021年第5期31卷 867-887页

作者： Mark Colwell Russell Frith Colwell Geotechnical Services CaloundraQLD 4551Australia Mine Advice pty.ltd BeresfieldNSW 2322Australia

As per most other earth science engineering problems,the underground coal geotechnical environment and the way in which roof and rib support interacts with the rock mass are complex *** is therefore generally recognised that without prudent simplification,the complexity of the problem will overwhelm all current geotechnical methods of modelling,not least for the reason that a rock mass can never be characterised to a level that allows a"non-simplified"*** fact that numerical models,which are commonly purported to be a"simulation"tool and the so-called epitome of advanced geotechnical engineering,always need to be"calibrated"to a known reality is taken to be conclusive proof of this *** the problem should not be oversimplified(*** dominant failure mechanisms or critical data input parameters should not be ignored),without question judicious simplification is at the heart of all engineering design,to the point that it has a well-established name–"reductionism".The hypothesis addressed in this paper,is that horizontal and vertical stress-driven slender beam and column behaviour(which includes unstable Euler Buckling)are respectively the dominant(but not only)roadway roof and ribline behavioural mechanism that(if not controlled)can lead to excessive deformation,failure and eventual *** a part of the Scientific Method,a hypothesis can only be tested via real-world observations,measurements and analyses in establishing it is a credible *** the Scientific Method,this paper demonstrates that slender beam/column behaviour is the dominant instability mechanism within a coal mine roof/rib subject to elevated horizontal/vertical stress conditions and therefore,must be representatively accounted for in any credible empirical,analytical,or numerical approach to coal mine roof/rib stability assessment and associated ground support design.

关键词： Prudent simplification Behavioural mechanisms Support design Delamination Axial stress Buckling