By using the center projection image sequence to estimate 3-D motion parameters,one needs to know the corresponding relationship between the feature of motion object in spaceand the projection coordinate on image plan...By using the center projection image sequence to estimate 3-D motion parameters,one needs to know the corresponding relationship between the feature of motion object in spaceand the projection coordinate on image plane.In order to avoid using the relationship of featurecorrespondence,the tensor analysis method in the affine transformation system is presented,andthe simulation data of experimental results are given.展开更多
Due to rainfall infiltration,groundwater activity,geological processes,and natural erosion,soil often exhibits heterogeneity and unsaturation.Additionally,seismic events can compromise slope stability.Existing analyti...Due to rainfall infiltration,groundwater activity,geological processes,and natural erosion,soil often exhibits heterogeneity and unsaturation.Additionally,seismic events can compromise slope stability.Existing analytical solutions typically consider a single failure mode,leading to inaccurate slope stability assessments.This study analyzes the impact of matric suction through three nonlinear shear strength models and adopts a heterogeneous soil model where cohesion linearly increases with depth.An improved pseudo-dynamic method is used to account for seismic effects.Based on a three-dimensional(3D)trumpet-shaped rotational failure mechanism,a new framework is established to analyze the stability of 3D two-bench slopes in heterogeneous unsaturated soil under seismic effects.The internal energy dissipation rate and external power at failure are calculated,and the gravity increase method is introduced to derive an explicit expression for the safety factor(F_(s)).The results are compared with previously published results,demonstrating the effectiveness of the proposed method.Sensitivity analyses on different parameters are conducted,discussing the influence of various factors on F s.This study proposes a new formula for calculating the F_(s) of 3D two-bench slopes in heterogeneous unsaturated soil under seismic effects,providing a practical application for slope engineering.展开更多
Accurate 3-D fracture network model for rock mass in dam foundation is of vital importance for stability,grouting and seepage analysis of dam foundation.With the aim of reducing deviation between fracture network mode...Accurate 3-D fracture network model for rock mass in dam foundation is of vital importance for stability,grouting and seepage analysis of dam foundation.With the aim of reducing deviation between fracture network model and measured data,a 3-D fracture network dynamic modeling method based on error analysis was proposed.Firstly,errors of four fracture volume density estimation methods(proposed by ODA,KULATILAKE,MAULDON,and SONG)and that of four fracture size estimation methods(proposed by EINSTEIN,SONG and TONON)were respectively compared,and the optimal methods were determined.Additionally,error index representing the deviation between fracture network model and measured data was established with integrated use of fractal dimension and relative absolute error(RAE).On this basis,the downhill simplex method was used to build the dynamic modeling method,which takes the minimum of error index as objective function and dynamically adjusts the fracture density and size parameters to correct the error index.Finally,the 3-D fracture network model could be obtained which meets the requirements.The proposed method was applied for 3-D fractures simulation in Miao Wei hydropower project in China for feasibility verification and the error index reduced from 2.618 to 0.337.展开更多
The vector method (VM) of quantitative texture analysis has been entirely reconstructedin the Euler space using Roe’s notation. The reconstructed VM, called the generalized vectormethod (GVM), has got rid of the limi...The vector method (VM) of quantitative texture analysis has been entirely reconstructedin the Euler space using Roe’s notation. The reconstructed VM, called the generalized vectormethod (GVM), has got rid of the limitations arising from the original form of orientationrepresentation of the VM, such as the inconvenience in searching the relation between tex-tures and physical properties of materials, and conserves all the advantages of VM. The investigation on a cubic crystal system indicates that the texture vector of a samplemay be quantitatively determined with the GVM, using a complete or even an incompletepole figure. Also, the series expansion coefficients of the crystallite orientation distributionfunction (ODF) needed in calculating macroscopic anisotropies of the sample can be easilyevaluated.展开更多
Transient magnetic circuit method is adopted to calculate the power loss in winding and shading coil. Based on the analysis of heat transfer process in AC contactor, a thermal model is proposed and the temperature fie...Transient magnetic circuit method is adopted to calculate the power loss in winding and shading coil. Based on the analysis of heat transfer process in AC contactor, a thermal model is proposed and the temperature field distribution is simulated with 3-D FEM of ANSYS. Comparison of simulation results with measurements shows that the proposed method is effective.展开更多
The transports of dust are calculated using 3-dimensional(3-D)trajectory method for three cases of duststorms in the terrain-following coordinate system,and the synoptic processes are also discussed for each case.The ...The transports of dust are calculated using 3-dimensional(3-D)trajectory method for three cases of duststorms in the terrain-following coordinate system,and the synoptic processes are also discussed for each case.The case of 17—20 April 1980,a severe duststorm was associated with the rapid development of a cyclone over the Mongolia Plateau.The dust moved from west to east across several deserts,formed a typical dust path in spring.The other two were weaker and the dust was triggered by the strong wind behind the cold front from northwest or north.Because the vertical velocity is considered in 3-D trajectory analysis,trajectories calculated should better reveal the transport rule of the dust particles and the results seem to be more consistent with the synoptic processes.The trajectory analysis on the 2-D isobaric sur- faces is simpler but can be used only in the conditions with weak vertical wind shear and weak vertical velocity.The dif- ference of trajectories at lower levels between two methods may be caused by the different treatment of orography.展开更多
文摘By using the center projection image sequence to estimate 3-D motion parameters,one needs to know the corresponding relationship between the feature of motion object in spaceand the projection coordinate on image plane.In order to avoid using the relationship of featurecorrespondence,the tensor analysis method in the affine transformation system is presented,andthe simulation data of experimental results are given.
基金Project(51378510)supported by the National Natural Science Foundation of China。
文摘Due to rainfall infiltration,groundwater activity,geological processes,and natural erosion,soil often exhibits heterogeneity and unsaturation.Additionally,seismic events can compromise slope stability.Existing analytical solutions typically consider a single failure mode,leading to inaccurate slope stability assessments.This study analyzes the impact of matric suction through three nonlinear shear strength models and adopts a heterogeneous soil model where cohesion linearly increases with depth.An improved pseudo-dynamic method is used to account for seismic effects.Based on a three-dimensional(3D)trumpet-shaped rotational failure mechanism,a new framework is established to analyze the stability of 3D two-bench slopes in heterogeneous unsaturated soil under seismic effects.The internal energy dissipation rate and external power at failure are calculated,and the gravity increase method is introduced to derive an explicit expression for the safety factor(F_(s)).The results are compared with previously published results,demonstrating the effectiveness of the proposed method.Sensitivity analyses on different parameters are conducted,discussing the influence of various factors on F s.This study proposes a new formula for calculating the F_(s) of 3D two-bench slopes in heterogeneous unsaturated soil under seismic effects,providing a practical application for slope engineering.
基金Project(51321065)supported by the Innovative Research Groups of the National Natural Science Foundation of ChinaProject(2013CB035904)supported by the National Basic Research Program of China(973 Program)Project(51439005)supported by the National Natural Science Foundation of China
文摘Accurate 3-D fracture network model for rock mass in dam foundation is of vital importance for stability,grouting and seepage analysis of dam foundation.With the aim of reducing deviation between fracture network model and measured data,a 3-D fracture network dynamic modeling method based on error analysis was proposed.Firstly,errors of four fracture volume density estimation methods(proposed by ODA,KULATILAKE,MAULDON,and SONG)and that of four fracture size estimation methods(proposed by EINSTEIN,SONG and TONON)were respectively compared,and the optimal methods were determined.Additionally,error index representing the deviation between fracture network model and measured data was established with integrated use of fractal dimension and relative absolute error(RAE).On this basis,the downhill simplex method was used to build the dynamic modeling method,which takes the minimum of error index as objective function and dynamically adjusts the fracture density and size parameters to correct the error index.Finally,the 3-D fracture network model could be obtained which meets the requirements.The proposed method was applied for 3-D fractures simulation in Miao Wei hydropower project in China for feasibility verification and the error index reduced from 2.618 to 0.337.
基金Project supported by the National Natural Science Foundation of China.
文摘The vector method (VM) of quantitative texture analysis has been entirely reconstructedin the Euler space using Roe’s notation. The reconstructed VM, called the generalized vectormethod (GVM), has got rid of the limitations arising from the original form of orientationrepresentation of the VM, such as the inconvenience in searching the relation between tex-tures and physical properties of materials, and conserves all the advantages of VM. The investigation on a cubic crystal system indicates that the texture vector of a samplemay be quantitatively determined with the GVM, using a complete or even an incompletepole figure. Also, the series expansion coefficients of the crystallite orientation distributionfunction (ODF) needed in calculating macroscopic anisotropies of the sample can be easilyevaluated.
文摘Transient magnetic circuit method is adopted to calculate the power loss in winding and shading coil. Based on the analysis of heat transfer process in AC contactor, a thermal model is proposed and the temperature field distribution is simulated with 3-D FEM of ANSYS. Comparison of simulation results with measurements shows that the proposed method is effective.
基金This project is supported by Doctoral Programme Foundation of Institution of Higher Education.
文摘The transports of dust are calculated using 3-dimensional(3-D)trajectory method for three cases of duststorms in the terrain-following coordinate system,and the synoptic processes are also discussed for each case.The case of 17—20 April 1980,a severe duststorm was associated with the rapid development of a cyclone over the Mongolia Plateau.The dust moved from west to east across several deserts,formed a typical dust path in spring.The other two were weaker and the dust was triggered by the strong wind behind the cold front from northwest or north.Because the vertical velocity is considered in 3-D trajectory analysis,trajectories calculated should better reveal the transport rule of the dust particles and the results seem to be more consistent with the synoptic processes.The trajectory analysis on the 2-D isobaric sur- faces is simpler but can be used only in the conditions with weak vertical wind shear and weak vertical velocity.The dif- ference of trajectories at lower levels between two methods may be caused by the different treatment of orography.
