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Landslide Reliability Analysis Based on Transfer Coefficient Method: A Case Study from Three Gorges Reservoir

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Journal of Earth Science 2012年第2期23卷 187-198页

作者：毕仁能 dominik ehret 项伟 Joachim Rohn Markus Schleier 江洎洧 Three Gorges Research Center for Geo-hazard Ministry of EducationChina University of Geosciences Department of Applied Geology University of Erlangen-Nuremberg State Office for Geology Resources and Mining of Baden-WürttembergFreiburg i.Br.Germany Faculty of Engineering China University of Geosciences

To evaluate the reliability of a landslide in a reservoir, the universal transfer coefficient method, which is popularized by the Chinese standard, is adopted as performance function in this study for：（1） common deterministic method stability evaluation; （2） reliability evaluation based on a Monte Carlo method; （3） comparison of landslide reliability under different water levels and under different correlation coefficients between soil shear strength parameters （c, Φ）, respectively with mean, standard deviation, reliability coefficient and failure probability. This article uses the Bazimen （八字门） landslide, which is located at the outlet of Xiangxi （香溪） River in the Three Gorges Reservoir, as an example to evaluate its stability and reliability under different water levels with two-dimensional deterministic and probabilistic methods. With the assumption that constant mean and normal distributed shear strength parameters （c, Φ）, correlation coefficient c, Φ=-1 based reliability analysis, compared with c, Φ=0 and 1, indicates obviously more increase of reliability index and lower standard deviation as water levels rise. To the case of a certain water level, c, Φ=-1 does not have constantly positive or negative effects on landslide reliability compared with c, Φ=0 or 1, but is associated with water level. Whereas the safety factor Fs by deterministic method, which is almost the same value as corresponding mean of safety factor from probabilistic analysis, will increase slightly as water level increases.

关键词： transfer coefficient method,Monte Carlo method water level fluctuation landslide stability reliability Three Gorges Reservoir.

Lithological and Structural Control of Hattian Bala Rock Avalanche Triggered by the Kashmir Earthquake 2005, Sub-Himalayas, Northern Pakistan

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Journal of Earth Science 2012年第2期23卷 213-224页

作者： Muhammad Basharat Joachim Rohn dominik ehret Mirza Shahid Baig GeoZentrum Nordbayern Friedrich-Alexander-University Erlangen-Nuremberg Institute of Geology University of Azad Jammu and Kashmir

The Kashmir earthquake 2005 （magnitude MW 7.6） triggered thousands of mass move-ments in northern Pakistan. These mass movements were mainly rock falls, debris falls, rockslides and rock avalanches. The mass movements vary in size from a few hundred cubic meters up to about 100 million cubic meters estimated for the Hattian Bala rock avalanche, the biggest one associated with this earthquake. This mass movement, which moved in southeastern direction, created two natural dams on the valley bottom and blocked the water ways of the Karli and Tung tributaries of the Jhelum River. Topographic, lithologic and structural information were used to investigate the Hattian Bala rock ava-lanche. Geotechnical and structural maps were prepared to understand relationship between geology and structure of Hattian Bala rock avalanche. The geometry and failure mode of this rock avalanche are controlled by southeast plunging synclinal structures, lithology, a bedding parallel slip surface and a pre-existing old rockslide. The structural map shows that the mass movement failure was due to Danna and Dandbeh synclinal structures plunging southeast on the hanging wall block of the reacti-vated Muzaffarabad fault. The slip surface of the mass movement followed the bedding planes along mudstone, claystone and sandstone surfaces. The mass movement perfectly followed the pre-existing synclinal morphology of the Danna and Dandbeh synclines.

关键词： Kashmir earthquake 2005 mass movement rock avalanche Muzaffarabad fault northern Pakistan.

Frequency Ratio Analysis of Mass Movements in the Xiangxi Catchment, Three Gorges Reservoir Area, China

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Journal of Earth Science 2010年第6期21卷 824-834页

作者： dominik ehret Joachim Rohn Christian Dumperth Susan Eckstein Stefanie Ernstberger Karel Otte René Rudolph Johannes Wiedenmann 项伟毕仁能 Department of Applied Geology University of Erlangen-Nuremberg Faculty of Engineering China University of Geosciences

In 2003, the Three Gorges Project （TGP, China）, currently the world＇s largest hydroelectric power plant by total capacity, went into operation. Due to large-scale impoundment of the Yangtze River and its tributaries and also due to resettlement, extensive environmental impacts like land use change and increase of geohazards are associated with the TGP. Within the Yangtze Project, we investigate these effects for the Xiangxi （香溪） catchment which is part of the Three Gorges Reservoir. The aim of this study is to evaluate the susceptibility for mass movement within the Xiangxi River backwater area using geographic information system （GIS）. We used existing mass movements and the conditioning factors （geology, elevation, slope, curvature, land use, and land use change） for analyzing mass movement susceptibility. Mass movements and geology were mapped in the field to establish a mass movement inventory and a geological map. Land use and digital elevation model （DEM） were obtained from remote-sensing data. We determined the relation between mass movements and the conditioning factors by using the frequency ratio method and found strong relation between mass movements and both natural and human-influenced conditioning factors.

关键词： mass movement susceptibility GIS frequency ratio Xiangxi catchment Three Gorges Reservoir.

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恩施市志留系地层斜坡灾变智能化预测

自然灾害学报 2013年第6期22卷 48-56页

作者：曾斌项伟 Joachim Rohn dominik ehret 中国地质大学(武汉)环境学院湖北武汉430074 教育部长江三峡库区地质灾害研究中心湖北武汉430074 University of Erlangen-Nuremberg Erlangen 91052Germany

由于滑坡发生时间的不确定性及发生物理过程的非线性,决定了滑坡灾害预测研究的趋势是确定特定区域、特定条件下不稳定斜坡体演变成为滑坡的可能性,以及这些不稳定斜坡体空间分布规律的预测研究。以鄂西恩施市志留系地层潜在不稳定斜坡... 详细信息

由于滑坡发生时间的不确定性及发生物理过程的非线性,决定了滑坡灾害预测研究的趋势是确定特定区域、特定条件下不稳定斜坡体演变成为滑坡的可能性,以及这些不稳定斜坡体空间分布规律的预测研究。以鄂西恩施市志留系地层潜在不稳定斜坡为研究对象,建立了基于GIS和人工智能神经网络的适用于研究区志留系地层斜坡灾变空间预测的技术路线及方法:从数据采集、空间数据库建立、评价指标体系建立、智能化预测模块设计、斜坡灾变智能化预测系统集成等方面进行了深入研究,得到了研究区内在将来外界营力作用下可能演变成为滑坡的不稳定斜坡区空间的分布情况,并利用遥感数据结合野外实地调查对成果进行了验证。证明了计算机智能化理论与GIS技术结合应用于斜坡灾变空间预测分析的科学性、可行性以及可靠性。

关键词：志留系地层地理信息系统神经网络斜坡灾变空间预测