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| 1 | Homotopic mapping solving method for gain fluency of a laser pulse amplifier显示文摘The model for gain fluency of a laser pulse amplifier is studied. Using the homotopic mapping method, firstly, the system of the original model is packed up standardization; secondly, introducing a homotopic mapping, taking the property of the mapping, inducing a contrived parameter, the solving of a nonlinear problem translates into the solving of a linear problem. Then the approximate expressions of the solution for the corresponding model are obtained. And the precision for the approximate solution is compared. It illuminates that the obtained approximate solution using the homotopic mapping method possesses higher approximate degree. At one time, the expansion of solution through the homotopic mapping method can be kept in the analytic operation. Thus it also enables us through differential and integral operations to obtain other physics behavior for the gain fluency of laser pulse amplifier. | MO JiaQi1,2 1 Anhui Normal University, Wuhu 241000, China 2 Division of Computational Science, E-Institutes of Shanghai Universities, at SJTU, Shanghai 200240, China | 2009 | Science China(Physics,Mechanics & Astronomy)2009，52，7： | 124 |
| 2 | The Hoeke-Brown failure criterion and GSI-2018 edition显示文摘The HoekeBrown criterion was introduced in 1980 to provide input for the design of underground excavations in rock.The criterion now incorporates both intact rock and discontinuities,such as joints,characterized by the geological strength index(GSI),into a system designed to estimate the mechanical behaviour of typical rock masses encountered in tunnels,slopes and foundations.The strength and deformation properties of intact rock,derived from laboratory tests,are reduced based on the properties of discontinuities in the rock mass.The nonlinear HoekeBrown criterion for rock masses is widely accepted and has been applied in many projects around the world.While,in general,it has been found to provide satisfactory estimates,there are several questions on the limits of its applicability and on the inaccuracies related to the quality of the input data.This paper introduces relatively few fundamental changes,but it does discuss many of the issues of utilization and presents case histories to demonstrate practical applications of the criterion and the GSI system. | E.Hoek E.T.Brown | 2019 | Journal of Rock Mechanics and Geotechnical Engineering2019，11，3： | 85 |
| 3 | Five hundred meter aperture spherical radio telescope (FAST)显示文摘Five hundred meter aperture spherical radio telescope (FAST) will be the largest radio telescope in the world. The innovative engineering concept and design pave a new road to realizing a huge single dish in the most effective way. Three outstanding features of the telescope are the unique karst depressions as the sites, the active main reflector which corrects spherical aberration on the ground to achieve full polarization and a wide band without involving a complex feed system, and the light focus cabin driven by cables and servomechanism plus a parallel robot as secondary adjustable system to carry the most precise parts of the receivers. Being the most sensitive radio telescope, FAST will enable astronomers to jumpstart many of the science goals, for example, the neutral hydrogen line surveying in distant galaxies out to very large redshifts, looking for the first shining star, detecting thousands of new pulsars, etc. Extremely interesting and exotic objects may yet await discovery by FAST. As a multi-science platform, the telescope will provide treasures to astronomers, as well as bring prosperity to other research, e.g. space weather study, deep space exploration and national security. The construction of FAST itself is expected to promote the development in high technology of relevant fields. | NAN Rendong | 2006 | Science China(Physics,Mechanics & Astronomy)2006，49，2： | 77 |
| 4 | METAMORPHIC MECHANISMSAND THEIR CONFIGURATION MODELS显示文摘The concept of metamorphic mechanisms is presented, configuration models and configuration transformations relating to a set of new matrix operations are discussed and proposed. The configuration of a metamorphic mechanism reflects the connectivity change in the mechanism during motions which results in mobility change and presents the characteristics of the mechanism which is discussed in various applications particularly in decorative artifacts. The characteristics is further investigated with mobility analysis. | Dai Jiansheng (Department of Mechanical Engineering, School of Physical Sciences and Engineering, King’s College, University of London,Strand,London WC2R 2LS, United kingdom) Zhang Qixian (Robotics Research Institute,Beijing University of Aeronautics and | 2000 | Chinese Journal of Mechanical Engineering2000，13，3： | 61 |
| 5 | Dynamic rock tests using split Hopkinson (Kolsky) bar system - A review显示文摘Dynamic properties of rocks are important in a variety of rock mechanics and rock engineering problems.Due to the transient nature of the loading, dynamic tests of rock materials are very different from and much more challenging than their static counterparts. Dynamic tests are usually conducted using the split Hopkinson bar or Kolsky bar systems, which include both split Hopkinson pressure bar(SHPB) and split Hopkinson tension bar(SHTB) systems. Signi fi cant progress has been made on the quanti fi cation of various rock dynamic properties, owing to the advances in the experimental techniques of SHPB system.This review aims to fully describe and critically assess the detailed procedures and principles of techniques for dynamic rock tests using split Hopkinson bars. The history and principles of SHPB are outlined,followed by the key loading techniques that are useful for dynamic rock tests with SHPB(i.e. pulse shaping, momentum-trap and multi-axial loading techniques). Various measurement techniques for rock tests in SHPB(i.e. X-ray micro computed tomography(CT), laser gap gauge(LGG), digital image correlation(DIC), Moiré method, caustics method, photoelastic coating method, dynamic infrared thermography) are then discussed. As the main objective of the review, various dynamic measurement techniques for rocks using SHPB are described, including dynamic rock strength measurements(i.e.dynamic compression, tension, bending and shear tests), dynamic fracture measurements(i.e. dynamic imitation and propagation fracture toughness, dynamic fracture energy and fracture velocity), and dynamic techniques for studying the in fl uences of temperature and pore water. | Kaiwen Xia Wei Yao | 2015 | Journal of Rock Mechanics and Geotechnical Engineering2015，7，1： | 72 |
| 6 | The influence of microwave irradiation on rocks for microwaveassisted underground excavation显示文摘Demand is growing for explosive-free rock breakage systems for civil and mining engineering, and spaceindustry applications. This paper highlights the work being undertaken in the Geomechanics Laboratoryof McGill University to make a real application of microwave-assisted mechanical rock breakage to fullfacetunneling machines and drilling. Comprehensive laboratory tests investigated the effect of microwaveradiation on temperature profiles and strength reduction in hard rocks (norite, granite, and basalt)for a range of exposure times and microwave power levels. The heating rate on the surface of the rockspecimens linearly decreased with distance between the sample and the microwave antenna, regardlessof microwave power level and exposure time. Tensile and uniaxial compressive strengths were reducedwith increasing exposure time and power level. Scanning electron micrographs (SEMs) highlightedfracture development in treated basalt. It was concluded that the microwave power level has a strongpositive influence on the amount of heat damage induced to the rock surface. Numerical simulations ofelectric field intensity and wave propagation conducted with COMSOL Multiphysics software generatedtemperature profiles that were in close agreement with experimental results. | Ferri Hassani Pejman M.Nekoovaght Nima Gharib | 2016 | Journal of Rock Mechanics and Geotechnical Engineering2016，8，1： | 69 |
| 7 | The Beishan underground research laboratory for geological disposal of high-level radioactive waste in China:Planning, site selection,site characterization and in situ tests显示文摘With the rapid development of nuclear power in China, the disposal of high-level radioactive waste(HLW) has become an important issue for nuclear safety and environmental protection. Deep geological disposal is internationally accepted as a feasible and safe way to dispose of HLW, and underground research laboratories(URLs) play an important and multi-faceted role in the development of HLW repositories. This paper introduces the overall planning and the latest progress for China's URL. On the basis of the proposed strategy to build an area-specific URL in combination with a comprehensive evaluation of the site selection results obtained during the last 33 years, the Xinchang site in the Beishan area,located in Gansu Province of northwestern China, has been selected as the final site for China's first URL built in granite. In the process of characterizing the Xinchang URL site, a series of investigations,including borehole drilling,geological mapping, geophysical surveying,hydraulic testing and in situ stress measurements, has been conducted. The investigation results indicate that the geological,hydrogeological, engineering geological and geochemical conditions of the Xinchang site are very suitable for URL construction. Meanwhile, to validate and develop construction technologies for the Beishan URL, the Beishan exploration tunnel(BET), which is a 50-m-deep facility in the Jiujing sub-area, has been constructed and several in situ tests, such as drill-and-blast tests, characterization of the excavation damaged zone(EDZ), and long-term deformation monitoring of surrounding rocks, have been performed in the BET. The methodologies and technologies established in the BET will serve for URL construction.According to the achievements of the characterization of the URL site, a preliminary design of the URL with a maximum depth of 560 m is proposed and necessary in situ tests in the URL are planned. | Ju Wang Liang Chen Rui Su Xingguang Zhao | 2018 | Journal of Rock Mechanics and Geotechnical Engineering2018，10，3： | 62 |
| 8 | Failure mechanism and coupled static-dynamic loading theory in deep hard rock mining: A review显示文摘Rock failure phenomena,such as rockburst,slabbing(or spalling) and zonal disintegration,related to deep underground excavation of hard rocks are frequently reported and pose a great threat to deep mining.Currently,the explanation for these failure phenomena using existing dynamic or static rock mechanics theory is not straightforward.In this study,new theory and testing method for deep underground rock mass under coupled static-dynamic loading are introduced.Two types of coupled loading modes,i.e.'critical static stress + slight disturbance' and 'elastic static stress + impact disturbance',are proposed,and associated test devices are developed.Rockburst phenomena of hard rocks under coupled static-dynamic loading are successfully reproduced in the laboratory,and the rockburst mechanism and related criteria are demonstrated.The results of true triaxial unloading compression tests on granite and red sandstone indicate that the unloading can induce slabbing when the confining pressure exceeds a certain threshold,and the slabbing failure strength is lower than the shear failure strength according to the conventional Mohr-Column criterion.Numerical results indicate that the rock unloading failure response under different in situ stresses and unloading rates can be characterized by an equivalent strain energy density.In addition,we present a new microseismic source location method without premeasuring the sound wave velocity in rock mass,which can efficiently and accurately locate the rock failure in hard rock mines.Also,a new idea for deep hard rock mining using a non-explosive continuous mining method is briefly introduced. | Xibing Li Fengqiang Gong Ming Tao Longjun Dong Kun Du Chunde Ma Zilong Zhou Tubing Yin | 2017 | Journal of Rock Mechanics and Geotechnical Engineering2017，9，4： | 68 |
| 9 | Numerical Simulation and Analysis of Solid-liquid Two-phase Flow in Centrifugal Pump显示文摘The flow with solid-liquid two-phase media inside centrifugal pumps is very complicated and the relevant method for the hydraulic design is still immature so far.There exist two main problems in the operation of the two-phase flow pumps,i.e.,low overall efficiency and severe abrasion.In this study,the three-dimensional,steady,incompressible,and turbulent solid-liquid two-phase flows in a low-specific-speed centrifugal pump are numerically simulated and analyzed by using a computational fluid dynamics(CFD) code based on the mixture model of the two-phase flow and the RNG k-two-equation turbulence model,in which the influences of rotation and curvature are fully taken into account.The coupling between impeller and volute is implemented by means of the frozen rotor method.The simulation results predicted indicate that the solid phase properties in two-phase flow,especially the concentration,the particle diameter and the density,have strong effects on the hydraulic performance of the pump.Both the pump head and the efficiency are reduced with increasing particle diameter or concentration.However,the effect of particle density on the performance is relatively minor.An obvious jet-wake flow structure is presented near the volute tongue and becomes more remarkable with increasing solid phase concentration.The suction side of the blade is subject to much more severe abrasion than the pressure side.The obtained results preliminarily reveal the characteristics of solid-liquid two-phase flow in the centrifugal pump,and are helpful for improvement and empirical correction in the hydraulic design of centrifugal pumps. | ZHANG Yuliang LI Yi CUI Baoling ZHU Zuchao DOU Huashu | 2013 | Chinese Journal of Mechanical Engineering2013，26，1： | 55 |
| 10 | Noether symmetries of the nonconservative and nonholonomic systems on time scales显示文摘In this paper we give a new method to investigate Noether symmetries and conservation laws of nonconservative and nonholonomic mechanical systems on time scales , which unifies the Noether's theories of the two cases for the continuous and the discrete nonconservative and nonholonomic systems. Firstly, the exchanging relationships between the isochronous variation and the delta derivatives as well as the relationships between the isochronous variation and the total variation on time scales are obtained. Secondly, using the exchanging relationships, the Hamilton's principle is presented for nonconservative systems with delta derivatives and then the Lagrange equations of the systems are obtained. Thirdly, based on the quasi-invariance of Hamiltonian action of the systems under the infinitesimal transformations with respect to the time and generalized coordinates, the Noether's theorem and the conservation laws for nonconservative systems on time scales are given. Fourthly, the d'Alembert-Lagrange principle with delta derivatives is presented, and the Lagrange equations of nonholonomic systems with delta derivatives are obtained. In addition, the Noether's theorems and the conservation laws for nonholonomic systems on time scales are also obtained. Lastly, we present a new version of Noether's theorems for discrete systems. Several examples are given to illustrate the application of our results. | CAI PingPing FU JingLi GUO YongXin | 2013 | Science China(Physics,Mechanics & Astronomy)2013，56，5： | 52 |
| 11 | A review of discrete modeling techniques for fracturing processes in discontinuous rock masses显示文摘The goal of this review paper is to provide a summary of selected discrete element and hybrid finitee discrete element modeling techniques that have emerged in the field of rock mechanics as simulation tools for fracturing processes in rocks and rock masses. The fundamental principles of each computer code are illustrated with particular emphasis on the approach specifically adopted to simulate fracture nucleation and propagation and to account for the presence of rock mass discontinuities. This description is accompanied by a brief review of application studies focusing on laboratory-scale models of rock failure processes and on the simulation of damage development around underground excavations. | A.Lisjak G.Grasselli | 2014 | Journal of Rock Mechanics and Geotechnical Engineering2014，6，4： | 58 |
| 12 | Longwall mining “cutting cantilever beam theory” and 110 mining method in China——The third mining science innovation显示文摘With the third innovation in science and technology worldwide, China has also experienced this marvelous progress. Concerning the longwall mining in China, the 'masonry beam theory'(MBT) was first proposed in the 1960 s, illustrating that the transmission and equilibrium method of overburden pressure using reserved coal pillar in mined-out areas can be realized. This forms the so-called '121mining method', which lays a solid foundation for development of mining science and technology in China. The 'transfer rock beam theory'(TRBT) proposed in the 1980 s gives a further understanding for the transmission path of stope overburden pressure and pressure distribution in high-stress areas. In this regard, the advanced 121 mining method was proposed with smaller coal pillar for excavation design,making significant contributions to improvement of the coal recovery rate in that era. In the 21 st century,the traditional mining technologies faced great challenges and, under the theoretical developments pioneered by Profs. Minggao Qian and Zhenqi Song, the 'cutting cantilever beam theory'(CCBT) was proposed in 2008. After that the 110 mining method is formulated subsequently, namely one stope face,after the first mining cycle, needs one advanced gateway excavation, while the other one is automatically formed during the last mining cycle without coal pillars left in the mining area. This method can be implemented using the CCBT by incorporating the key technologies, including the directional presplitting roof cutting, constant resistance and large deformation(CRLD) bolt/anchor supporting system with negative Poisson's ratio(NPR) effect material, and remote real-time monitoring technology. The CCBT and 110 mining method will provide the theoretical and technical basis for the development of mining industry in China. | Manchao He Guolong Zhu Zhibiao Guo | 2015 | Journal of Rock Mechanics and Geotechnical Engineering2015，7，5： | 57 |
| 13 | Unsteady Turbulent Simulation and Pressure Fluctuation Analysis for Centrifugal Pumps显示文摘The pressure fluctuation in the flow passage of both impeller and casing is addressed on design condition.The initial conditions for the unsteady turbulent simulation are resulted from the steady calculations, and the three dimensional unsteady turbulent simulation concerning the rotor-stator interaction is executed by a Navier-Stoke solver embedded with k-ε turbulence model and with appropriate moving interface boundary conditions.Detecting points are distributed in the flow passage in different radial and circumferential positions to capture the static pressure fluctuation character for one cycle of the impeller.The time-domain spectrums show that the static pressure curves are periodic and have five peaks and five valleys.With the radius increasing, the pressure fluctuation peak-to-peak values in the impeller are increasing, and reach the maximum value on the interface.In the casing flow passage, those values are about 7% of local static pressure except some ones near the tongue.The values become decreasingly in the diffuser pipe.The frequency spectrums transformed by fast Fourier transform(FFT) show that the dominant frequency is approximate with the blade passing frequency, and the pressure fluctuations in impeller passage have high frequency content while those in casing ones have no such information. | YUAN Shouqi NI Yongyan PAN Zhongyong YUAN Jianping | 2009 | Chinese Journal of Mechanical Engineering2009，22，1： | 48 |
| 14 | Numerical and Experimental Investigation of High-efficiency Axial-flow Pump显示文摘The experimental investigation of axial-flow pump has been rapidly developed to meet the needs of South-to-North Water Diversion Project of China. Owing to the boundary conditions of hub, blade tip clearance, much of the physical phenomena and laws involved in this complex flow field can’t be fully determined. The flow characteristics of the high efficiency axial-flow pump have been simulated by RNG k –ε turbulence model and SIMPLEC arithmetic based on FLUENT software. Numerical results indicate that the data from the prediction show agreement with the experimental results, static pressure on pressure side of blades increases slightly at circumferential direction with radius increasing, and keep almost constant at the same radial while increasing gradually from inlet to exit on the suction side along flow direction at design conditions. The static pressure, total pressure and velocity at inlet, impeller outlet and vane outlet were measured by a five-hole probe, and a contrastive experiment was done to investigate the influence of hub leakage. The experimental results show that inlet flow is almost axial and the prerotation is very small at various conditions. The meridional velocity and circulation distribution are almost identical at impeller outlet at design conditions due to steady flow and high efficiency. The residual circulation exits at downstream of the guide vane, and the circumferential velocity component increases linearly from hub to tip at small flow rate conditions. Hub leakage in adjustable blades results in the decrease of the meridional velocity and circulation at blade exit near hub. The results of numerical simulation and experiments supply important flow structure information for the high-efficiency axial-flow pump. | SHI Weidong ZHANGDesheng GUAN Xingfan LENG Hongfei | 2010 | Chinese Journal of Mechanical Engineering2010，23，1： | 50 |
| 15 | Orbit determination and time synchronization for a GEO/IGSO satellite navigation constellation with regional tracking network显示文摘Aiming at regional services,the space segment of COMPASS (Phase I) satellite navigation system is a constellation of Geostationary Earth Orbit (GEO),Inclined Geostationary Earth Orbit (IGSO) and Medium Earth Orbit (MEO) satellites.Precise orbit determination (POD) for the satellites is limited by the geographic distribution of regional tracking stations.Independent time synchronization (TS) system is developed to supplement the regional tracking network,and satellite clock errors and orbit data may be obtained by simultaneously processing both tracking data and TS data.Consequently,inconsistency between tracking system and TS system caused by remaining instrumental errors not calibrated may decrease navigation accuracy.On the other hand,POD for the mixed constellation of GEO/IGSO/MEO with the regional tracking network leads to parameter estimations that are highly correlated.Notorious example of correlation is found between GEO's orbital elements and its clock errors.We estimate orbital elements and clock errors for a 3GEO+2IGSO constellation in this study using a multi-satellite precise orbit determination (MPOD) strategy,with which clock error elimination algorithm is applied to separate orbital and clock estimates to improve numerical efficiency.Satellite Laser Ranging (SLR) data are used to evaluate User Ranging Error (URE),which is the orbital error projected on a receiver's line-of-sight direction.Two-way radio-wave time transfer measurements are used to evaluate clock errors.Experimenting with data from the regional tracking network,we conclude that the fitting of code data is better than 1 m in terms of Root-Mean-Square (RMS),and fitting of carrier phase is better than 1 cm.For orbital evaluation,difference between computed receiver-satellite ranging based on estimated orbits and SLR measurements is better than 1 m (RMS).For clock estimates evaluation,2-hour linear-fitting shows that the satellite clock rates are about 1.E-10 s/s,while receiver clock rates are about 1×10 13-1×10 12 s/s.For the 72-hour POD experiment,the average differences between POD satellite clock rates estimates and clock measurements based on TS system are about 1×10 13 s/s,and for receiver clock rates,the differences are about 1×10 15 s/s. | ZHOU ShanShi HU XiaoGong WU Bin LIU Li QU WeiJing GUO Rui HE Feng CAO YueLing Wu XiaoLi ZHU LingFeng SHI Xin TAN HongLi | 2011 | Science China(Physics,Mechanics & Astronomy)2011，54，6： | 44 |
| 16 | Shear strength criteria for rock,rock joints,rockfill and rock masses:Problems and some solutions显示文摘Although many intact rock types can be very strong,a critical confining pressure can eventually be reached in triaxial testing,such that the Mohr shear strength envelope becomes horizontal.This critical state has recently been better defined,and correct curvature or correct deviation from linear Mohr-Coulomb(MC) has finally been found.Standard shear testing procedures for rock joints,using multiple testing of the same sample,in case of insufficient samples,can be shown to exaggerate apparent cohesion.Even rough joints do not have any cohesion,but instead have very high friction angles at low stress,due to strong dilation.Rock masses,implying problems of large-scale interaction with engineering structures,may have both cohesive and frictional strength components.However,it is not correct to add these,following linear M-C or nonlinear Hoek-Brown(H-B) standard routines.Cohesion is broken at small strain,while friction is mobilized at larger strain and remains to the end of the shear deformation.The criterion 'c then σn tan φ' should replace 'c plus σn tan φ' for improved fit to reality.Transformation of principal stresses to a shear plane seems to ignore mobilized dilation,and caused great experimental difficulties until understood.There seems to be plenty of room for continued research,so that errors of judgement of the last 50 years can be corrected. | Nick Barton | 2013 | Journal of Rock Mechanics and Geotechnical Engineering2013，5，4： | 41 |
| 17 | Fracture initiation and propagation in intact rock—A review显示文摘The initiation and propagation of failure in intact rock are a matter of fundamental importance in rock engineering. At low confining pressures, tensile fracturing initiates in samples at 40%e60% of the uniaxial compressive strength and as loading continues, and these tensile fractures increase in density, ultimately coalescing and leading to strain localization and macro-scale shear failure of the samples. The Griffith theory of brittle failure provides a simplified model and a useful basis for discussion of this process. The HoekeBrown failure criterion provides an acceptable estimate of the peak strength for shear failure but a cutoff has been added for tensile conditions. However, neither of these criteria adequately explains the progressive coalition of tensile cracks and the final shearing of the specimens at higher confining stresses. Grain-based numerical models, in which the grain size distributions as well as the physical properties of the component grains of the rock are incorporated, have proved to be very useful in studying these more complex fracture processes. | E.Hoek C.D.Martin | 2014 | Journal of Rock Mechanics and Geotechnical Engineering2014，6，4： | 43 |
| 18 | New omega vortex identification method显示文摘A new vortex identification criterion called W-method is proposed based on the ideas that vorticity overtakes deformation in vortex.The comparison with other vortex identification methods like Q-criterion and λ_2-method is conducted and the advantages of the new method can be summarized as follows:(1) the method is able to capture vortex well and very easy to perform;(2) the physical meaning of W is clear while the interpretations of iso-surface values of Q and λ_2 chosen to visualize vortices are obscure;(3)being different from Q and λ_2 iso-surface visualization which requires wildly various thresholds to capture the vortex structure properly, W is pretty universal and does not need much adjustment in different cases and the iso-surfaces of W=0.52 can always capture the vortices properly in all the cases at different time steps, which we investigated;(4) both strong and weak vortices can be captured well simultaneously while improper Q and λ_2 threshold may lead to strong vortex capture while weak vortices are lost or weak vortices are captured but strong vortices are smeared;(5) W=0.52 is a quantity to approximately define the vortex boundary. Note that, to calculate W, the length and velocity must be used in the non-dimensional form. From our direct numerical simulation, it is found that the vorticity direction is very different from the vortex rotation direction in general 3-D vortical flow,the Helmholtz velocity decomposition is reviewed and vorticity is proposed to be further decomposed to vortical vorticity and non-vortical vorticity. | ChaoQun Liu YiQian Wang Yong Yang ZhiWei Duan | 2016 | Science China(Physics,Mechanics & Astronomy)2016，59，8： | 49 |
| 19 | Reservoir-induced landslides and risk control in Three Gorges Project on Yangtze River,China显示文摘The Three Gorges region in China was basically a geohazard-prone area prior to construction of the Three Gorges Reservoir(TGR).After construction of the TGR,the water level was raised from 70 m to 175 m above sea level(ASL).and annual reservoir regulation has caused a 30-m water level difference after impoundment of the TGR since September 2008.This paper first presents the spatiotemporal distribution of landslides in six periods of 175 m ASL trial impoundments from 2008 to 2014.The results show that the number of landslides sharply decreased from 273 at the initial stage to less than ten at the second stage of impoundment.Based on this,the reservoir-induced landslides in the TGR region can be roughly classified into five failure patterns,i.e.accumulation landslide,dip-slope landslide,reversed bedding landslide,rockfall,and karst breccia landslide.The accumulation landslides and dip-slope landslides account for more than 90%.Taking the Shuping accumulation landslide(a sliding mass volume of 20.7 × 10~6 m^3) in Zigui County and the Outang dip-slope landslide(a sliding mass volume of about 90 × 10~6 m^3) in Fengjie County as two typical cases,the mechanisms of reactivation of the two landslides are analyzed.The monitoring data and factor of safety(FOS) calculation show that the accumulation landslide is dominated by water level variation in the reservoir as most part of the mass body is under 175 m ASL,and the dip-slope landslide is controlled by the coupling effect of reservoir water level variation and precipitation as an extensive recharge area of rainfall from the rear and the front mass is below 175 m ASL.The characteristics of landslide-induced impulsive wave hazards after and before reservoir impoundment are studied,and the probability of occurrence of a landslide-induced impulsive wave hazard has increased in the reservoir region.Simulation results of the Ganjingzi landslide in Wushan County indicate the strong relationship between landslide-induced surge and water variation with high potential risk to shipping and residential areas.Regarding reservoir regulation in TGR when using a single index,i.e.1-d water level variation,water resources are not well utilized,and there is also potential risk of disasters since 2008.In addition,various indices such as 1-d.5-d,and 10-d water level variations are proposed for reservoir regulation.Finally,taking reservoir-induced landslides in June2015 for example,the feasibility of the optimizing indices of water level variations is verified. | Yueping Yin Bolin Huang Wenpei Wang Yunjie Wei Xiaohan Ma Fei Ma Changjun Zhao | 2016 | Journal of Rock Mechanics and Geotechnical Engineering2016，8，5： | 45 |
| 20 | Defect Formation Mechanisms in Selective Laser Melting:A Review显示文摘Defect formation is a common problem in selective laser melting(SLM). This paper provides a review of defect formation mechanisms in SLM. It summarizes the recent research outcomes on defect findings and classification, analyzes formation mechanisms of the common defects, such as porosities, incomplete fusion holes, and cracks. The paper discusses the effect of the process parameters on defect formation and the impact of defect formation on the mechanical properties of a fabricated part. Based on the discussion, the paper proposes strategies for defect suppression and control in SLM. | Bi Zhang Yongtao Li Qian Bai | 2017 | Chinese Journal of Mechanical Engineering2017，30，3： | 50 |
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