Based on the principle of 3D particle flow code,a numerical landslide run-out model is presented to simulate the failure process of the Zhenggang landslide(in southwestern China) under the effect of water after a rain...Based on the principle of 3D particle flow code,a numerical landslide run-out model is presented to simulate the failure process of the Zhenggang landslide(in southwestern China) under the effect of water after a rainfall.The relationship between the micro-mechanical parameters and the macro-shear strength of the grain material is determined through numerical calibrations.Then the rainfall effect is considered in numerical simulations and rain-induced sliding processes are performed,which help us to discuss the mechanism of deformation and failure of this landslide together with field observations.It shows the Zhenggang landslide would most likely be activated in Zone I and would gain momentum in Zone II.In order to prevent the potential disaster,a tailing dam is advised to be designed about 175 m downstream from the current landslide boundary of Zone II.Verified by field observations,the presented landslide model can reflect the failure mechanism after rainfall.It can also provide a method to predict the potential disaster and draft disaster prevention measures.展开更多
In the reliability analysis of slope, the performance functions derived from the most available stability analysis procedures of slopes are usually implicit and cannot be solved by first-order second-moment approach. ...In the reliability analysis of slope, the performance functions derived from the most available stability analysis procedures of slopes are usually implicit and cannot be solved by first-order second-moment approach. A new reliability analysis approach was presented based on three-dimensional Morgenstem-Price method to investigate three-dimensional effect of landslide in stability analyses. To obtain the reliability index, Support Vector Machine （SVM） was applied to approximate the performance function. The time-consuming of this approach is only 0.028% of that using Monte-Carlo method at the same computation accuracy. Also, the influence of time effect of shearing strength parameters of slope soils on the long-term reliability of three-dimensional slopes was investigated by this new approach. It is found that the reliability index of the slope would decrease by 52.54% and the failure probability would increase from 0.000 705% to 1.966%. In the end, the impact of variation coefficients of c andfon reliability index of slopes was taken into discussion and the changing trend was observed.展开更多
Three-dimensional nonstationary model of aerodynamical interaction of turbine stage and exhaust hood is realized, based on nonstationary 3D codes for calculation of inviscid transonic flow through stage[3] and exhaust...Three-dimensional nonstationary model of aerodynamical interaction of turbine stage and exhaust hood is realized, based on nonstationary 3D codes for calculation of inviscid transonic flow through stage[3] and exhaust hood[4] which consist of diffuser and space under casing. The codes are built with the use of the explicit Godunov’s 2nd order difference scheme. Some results of flow simulation through the compartments "stage-exhaust hood," "stage-exhaust axial-radial diffuser" for wide range of volumetric flow rates are represented.展开更多
This article proposes a relay camera videometrics based method to convert an unstable measuring platform to a static reference to solve the problems of large error or invalidation caused by measuring platform instabil...This article proposes a relay camera videometrics based method to convert an unstable measuring platform to a static reference to solve the problems of large error or invalidation caused by measuring platform instability in photogrammetric and videometric measurements.The method installs a relay camera on the unstable platform and captures images of a reference marker fixed on a static reference or vice versa to resolve the 3D movement of the unstable platform relative to the static reference,based on which it corrects the error of the measured results and thus eliminating the influence of the platform movement.It finds new and important applications for videometrics by making high-precision dynamic measurement possible on unstable platforms.Verification experiments and numerical simulations have proven its validity and practicability.展开更多
基金The National Natural Science Foundation of China(Grants Nos.51309089,41472272 and 11202063)the National Key Technology R&D Program(Grant No.2013BAB06B00)+1 种基金the Natural Science Foundation of Jiangsu Province(Grant No.BK20130846)the Fundamental Research Funds for the Central Universities(Grant No.2015B06014)supported this work
文摘Based on the principle of 3D particle flow code,a numerical landslide run-out model is presented to simulate the failure process of the Zhenggang landslide(in southwestern China) under the effect of water after a rainfall.The relationship between the micro-mechanical parameters and the macro-shear strength of the grain material is determined through numerical calibrations.Then the rainfall effect is considered in numerical simulations and rain-induced sliding processes are performed,which help us to discuss the mechanism of deformation and failure of this landslide together with field observations.It shows the Zhenggang landslide would most likely be activated in Zone I and would gain momentum in Zone II.In order to prevent the potential disaster,a tailing dam is advised to be designed about 175 m downstream from the current landslide boundary of Zone II.Verified by field observations,the presented landslide model can reflect the failure mechanism after rainfall.It can also provide a method to predict the potential disaster and draft disaster prevention measures.
基金Project(50878082) supported by the National Natural Science Foundation of ChinaProject(200631880237) supported by the Science and Technology Program of West Transportation of the Ministry of Transportation of ChinaKey Project(09JJ3104) supported by the Natural Science Foundation of Hunan Province, China
文摘In the reliability analysis of slope, the performance functions derived from the most available stability analysis procedures of slopes are usually implicit and cannot be solved by first-order second-moment approach. A new reliability analysis approach was presented based on three-dimensional Morgenstem-Price method to investigate three-dimensional effect of landslide in stability analyses. To obtain the reliability index, Support Vector Machine （SVM） was applied to approximate the performance function. The time-consuming of this approach is only 0.028% of that using Monte-Carlo method at the same computation accuracy. Also, the influence of time effect of shearing strength parameters of slope soils on the long-term reliability of three-dimensional slopes was investigated by this new approach. It is found that the reliability index of the slope would decrease by 52.54% and the failure probability would increase from 0.000 705% to 1.966%. In the end, the impact of variation coefficients of c andfon reliability index of slopes was taken into discussion and the changing trend was observed.
文摘Three-dimensional nonstationary model of aerodynamical interaction of turbine stage and exhaust hood is realized, based on nonstationary 3D codes for calculation of inviscid transonic flow through stage[3] and exhaust hood[4] which consist of diffuser and space under casing. The codes are built with the use of the explicit Godunov’s 2nd order difference scheme. Some results of flow simulation through the compartments "stage-exhaust hood," "stage-exhaust axial-radial diffuser" for wide range of volumetric flow rates are represented.
基金supported by the National Natural Science Foundation of China (Grant Nos.11072263,10727202)
文摘This article proposes a relay camera videometrics based method to convert an unstable measuring platform to a static reference to solve the problems of large error or invalidation caused by measuring platform instability in photogrammetric and videometric measurements.The method installs a relay camera on the unstable platform and captures images of a reference marker fixed on a static reference or vice versa to resolve the 3D movement of the unstable platform relative to the static reference,based on which it corrects the error of the measured results and thus eliminating the influence of the platform movement.It finds new and important applications for videometrics by making high-precision dynamic measurement possible on unstable platforms.Verification experiments and numerical simulations have proven its validity and practicability.
