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3D finite element method （FEM） simulation of groundwater flow during backward erosion piping

Frontiers of Structural and Civil Engineering 2014年第2期8卷 160-166页

作者： Kristine VANDENBOER Vera van BEEK Adam BEZUIJEN Department of Civil Engineering Ghent University Ghent 9000 Belgium Deltares Delft 2628 Netherlands section geoengineering Delft University of Technology Delft 2628 Netherlands

Backward erosion piping is an important failure mechanism for cohesive water retaining structures which are founded on a sandy aquifer. At present, the prediction models for safety assessment are often based on 2D assumptions. In this work, a 3D numerical approach of the groundwater flow leading to the erosion mechanism of backward erosion piping is presented and discussed. Comparison of the 2D and 3D numerical results explicitly demonstrates the inherent 3D nature of the piping phenomenon. In addition, the influence of the seepage length is investigated and discussed for both piping initiation and piping progression. The results clearly indicate the superiority of the presented 3D numerical model compared to the established 2D approach. Moreover, the 3D numerical results enable a better understanding of the complex physical mechanism involved in backward erosion piping and thus can lead to a significant improvement in the safety assessment of water retaining structures.

关键词： backward erosion piping groundwater flow 3D finite element method (FEM)

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Updating the coal quality parameters in multiple production benches based on combined material measurement： a full case study

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International Journal of Coal Science & Technology 2017年第2期4卷 159-171页

作者： Cansln Yiiksel Jorg Benndorf Matthias Lindig Oliver Lohstrater Resource Engineering section Department of Geoscienceand Engineering Delft University of Technology Stevinweg1 2628 CN Delft The Netherlands Institute for Mine Surveying and Geodesy Faculty ofGeosciences Geoengineering and Mining University of Technology Bergakademie Freiberg Reiche ZecheFuchsmuhlenweg 9 09599 Freiberg Germany Mitteldeutsche Braunkohlengesellschaft mbH GliJck-Auf-Strage 1 06711 Zeitz Germany

An efficient resource model updating framework concept was proposed aiming for the improvement of raw material quality control and process efficiency in any type of mining operation. The concept integrates sensor data measured online on the production line into the resource or grade/quality control model and continuously provides locally more accurate estimates. The concept has been applied in a lignite field with the aim of identifying local impurities in a coal seam and to improve the prediction of coal quality attributes in neighbouring blocks. A significant improvement was demonstrated which led to better coal quality management. So far, the proposed concept and the application in coal mining was limited to a case where online measurements were unambiguously trackable due to a single extraction face being the point of origin for the material. This contribution presents an extension to the case, where characteristics from blended material, originating from two or three simultaneously operating extraction faces, are measured. The challenge tackled in this contribution is the updating of local coal quality estimates in different production benches based on measurements of a blended material stream. For a practical application of the updating concept, which is based on the Ensemble Kalman Filter, a simple method for generating prior ensemble members based on block geometries defined in the short-term model and the variogram, is discussed. This method allows for a fast, semi-automated and rather simple generation of prior models instead of generating a fully simulated deposit model using conditional simulation in geostatistics. It should foster operational implementation in an industrial environment. The main purpose of this article is to investigate the applicability of the developed framework with a simplified prior resource model. In addition to this any model improvements due to the integration of sensor data obtained by observing a blend of coal from multiple ex

关键词： Resource model updating Online sensor Ensemble Kalman filter Multiple excavator Lignite Real application

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Characteristics of grain size distribution and the shear strength analysis of Chenjiaba long runout coseismic landslide

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Journal of Mountain Science 2019年第9期16卷 2110-2125页

作者： GETAHUN Ephrem QI Sheng-wen GUO Song-feng ZOU Yu LIANG Ning Key Laboratory of Shale Gas and geoengineering Institute of Geology and Geophysics Chinese Academy of Sciences Chaoyang District Beijing 100029 China Institute of Earth Science Chinese Academy of Sciences Beijing 100029 China University of Chinese Academy of Sciences Beijing 100049 China Arba Minch University Department of Geology P. O. Box 21 Arba Minch 00251 Ethiopia

Study on the grain size distribution characteristics and the frictional strength behavior of the slide deposits are helpful to disclose the landslide runout process and understand the mechanism of a long runout landslide. We performed grain size distribution analysis on samples collected from Chenjiaba landslide induced by Wenchuan earthquake. The grain size distribution of samples from the landslide sections quantitatively depicts a gradual coarsening upward grading from shear zone to the top section. Then a multistage-multiphase ring shearing approach was used to determine a comparative shear strength behavior of samples from each landslide section. In this method, a sample was sheared continuously for large displacement and fast rate on different normal stress conditions. The multiphase shear mode with a maximum of 105 mm/min rate has allowed observing the qualitative change and patterns of the frictional resistance behaviors of soils under different normal stresses. The results of coefficient of friction values under multiphase shear mode have shown substantial post peak shear weakening behaviors after large shear displacement that can be narrated with long runout processes. The shear strength test results indicate that the shear zone samples have developed higher friction angle values compared to overlying section samples, on the last phase of shear process, which may be very important to understand the braking mechanism of a long runout landslide.

关键词： Grain size distribution Long runout Landslide Multistage-Multiphase Ring Shear

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Landslide-risk zonation along mountainous highway considering rock mass classification

Landslide-risk zonation along mountainous highway considerin...

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中国科学院地质与地球物理研究所2015年度（第15届）学术年会

作者： Shengwen Qi Xingxing Li Songfeng Guo Zhifa Zhan Haijun Liao Key Laboratory of Shale Gas and geoengineering Institute of Geology and GeophysicsChinese Academy of Sciences University of Chinese Academy of Sciences Beijing Institute of Geology

Landslide and especially rockfall hazard widely occurs along cut slopes in mountainous *** risk assessment of mass movements is still one of most challenging problems in slope engineering *** propose a routine method to assess rock slide and rockfall risk of cut slopes essentially based on slope properties and rock mass *** method is a lean low-cost path to a risk *** block size is simplified into two classes,{small}with a volume less than 1.0 m and{large},greater than 1.0 *** indicate that for a slope with n small-medium rock blocks,the possibility of rockfalls can be estimated by 1-(1-P),in which P is the likelihood of one{small}rock block *** possibility of other types of mass movement can be determined by the firstorder second-moment(FOSM)*** on this,an exponent equation was adopted to evaluate the consequence and the *** methodology is demonstrated by a case study from the mountains of Mentougou district,Beijing,*** on the investigations of geological conditions(i.e.,lithology,weathering and rock mass structure)and some historical mass movement data of the cut slopes,a zonation map for rockfall and rock slide risk along a 17-km section of a road is *** result is supported by mass movement event observations in the recent 2 years.

关键词： Landslides Rockfall Rockslide Cut slope Risk Highway

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Experimental study on seismic response and progressive failure characteristics of bedding rock slopes

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第5期14卷 1394-1405页

作者： Mingdong Zang Guoxiang Yang Jinyu Dong Shengwen Qi Jianxian He Ning Liang School of Engineering and Technology China University of Geosciences(Beijing)Beijing100083China Institute of Geosafety China University of Geosciences(Beijing)Beijing100083China Research Institute of Geotechnical Engineering and Hydraulic Structure North China University of Water Resources and Electric PowerZhengzhou450011China Key Laboratory of Shale Gas and geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing100029China University of Chinese Academy of Sciences Beijing100049China Department of Geotechnical Engineering School of Civil EngineeringSouthwest Jiaotong UniversityChengdu610031China

Bedding rock slopes are common geological features in nature that are prone to failure under strong earthquakes. Their failures induce catastrophic landslides and form barrier lakes, posing severe threats to people’s lives and property. Based on the similarity criteria, a bedding rock slope model with a length of3 m, a width of 0.8 m, and a height of 1.6 m was constructed to facilitate large-scale shaking table *** results showed that with the increase of vibration time, the natural frequency of the model slope decreased, but the damping ratio increased. Damage to the rock mass structure altered the dynamic characteristics of the slope;therefore, amplification of the acceleration was found to be nonlinear and uneven. Furthermore, the acceleration was amplified nonlinearly with the increase of slope elevation along the slope surface and the vertical section, and the maximum acceleration amplification factor(AAF) occurred at the slope crest. Before visible deformation, the AAF increased with increasing shaking intensity;however, it decreased with increasing shaking intensity after obvious deformation. The slope was likely to slide along the bedding planes at a shallow depth below the slope surface. The upper part of the slope mainly experienced a tensile-shear effect, whereas the lower part suffered a compressive-shear force. The progressive failure process of the model slope can be divided into four stages, and the dislocated rock mass can be summarized into three zones. The testing data provide a good explanation of the dynamic behavior of the rock slope when subjected to an earthquake and may serve as a helpful reference in implementing antiseismic measures for earthquake-induced landslides.

关键词： Bedding rock slope Large-scale shaking table test Seismic response Progressive failure characteristics

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