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Journal of Thermal Science 2022年第6期31卷 1948-1958页

作者： LUO Jin ZHANG Qi PRIESS Anna rohn joachim Faculty of Engineering China University of Geosciences(Wuhan)Wuhan 430074China GeoZentrum Nordbayern University of Erlangen-NürnbergSchlossgarten 591054 ErlangenGermany

Operation strategies of Ground Source Heat Pump System(GSHPS) such as continuous or intermittent approaches have been extensively studied. In this work, a novel strategy was proposed to maximize the energy efficiency of GSHPS. In this approach, the buildings was first air-conditioned by the preheating/precooling mode and the rest thermal load was covered by the heat pump(HP) mode. The system performance can then be optimized by considering the combination of these two operating modes. A case study was made to examine the thermal performance of a GSHPS installed in Nuremberg, Germany. Thermal performance of the HP and the preheating/precooling operating modes was examined. The system was optimized by deploying the assistant preheating/precooling approach and over one-year period monitoring showed that the seasonal Coefficient of Performance(COP) of the GSHPS was 4.12 in winter and 5.01 in summer. These COP values are higher than that of the conventional GSHPS. Thus, this proposed strategy could be an efficient way to improve the thermal performance of GSHPS.

关键词： ground source heat pump system ground-air heat exchanger ground temperature response preheating and precooling

Using LIDAR and ground truth for landslide recognition and characterization of geotechnical and morphological parameters in sedimentary rocks,a case study in Northern Bavaria (Germany)

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Journal of Mountain Science 2017年第8期14卷 1513-1525页

作者： WIEDENMANN Johannes rohn joachim MOSER Michael GeoZentrum Nordbayern Department of Applied GeologyUniversity of Erlangen-Nürnberg

The use of LIDAR-derived shaded relief maps led to the identification of all potential landslide areas in a hilly region in Northern Bavaria(1590 km^2), Germany. Every possible structure was investigated by field investigation which resulted in a detailed database of 1002 landslides within the study area. The analysis of geological, lithological, topographical and morphological properties(spatial ratio, lithological and geological setting, length/width distribution, material properties and slope angle) revealed characteristic appearances of the landslides and possible relationships between different aspects. Strong relations between the lithological setting, spatial ratio of the mapped landslides and distribution of slope angle could be observed. This study shows the value of high-resolution shaded relief maps for detecting and mapping landslides in a large area with comparatively little work and time in comparison to the traditional approach to mapping. It reveals that many landslides were not known before. Landslides are much more common in Northern Bavaria and have a higher influence on the denudation rate of the Franconian Alb than expected before.

关键词： Landslides LIDAR Appearance Spatialratio Material properties Bavaria

Numerical Modelling of Seismic Site Effects Incorporating Non-linearity and Groundwater Level Changes

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Journal of Earth Science 2010年第6期21卷 931-940页

作者： Dominik Ehret joachim rohn Dieter Hannich Carlos Grandas Gerhard Huber Department of Applied Geology University of Erlangen-Nuremberg Department of Applied Geology University (TH) of Karlsruhe Institute of Soil and Rock Mechanics University (TH) of Karlsruhe

In the past decades, the necessity for detailed earthquake microzonation studies was recognized worldwide. Therefore, different approaches were established and applied. Unfortunately, the majority of these approaches are not based on pre-existing field data but require extensive seismic measurements and investigations. Furthermore, these approaches incorporate non-linearity inadequately and cannot take groundwater level changes into account. For this purpose, notably numerical models are most suitable. These models require a good knowledge of the local geological conditions （especially of the uppermost unconsolidated units）, information about the geotechnical parameters of these units, and a hydrogeological model of the investigated area. Most of this information can be obtained from geotechnical investigations and surveys that have already been carried out in most densely populated areas. In a case study for Bucharest City, non-linear analyses were performed using software that is based on the visco-hypoplastic constitutive law. The results indicate that groundwater level changes have an important influence on duration and amplitude of ground response and thus should be considered for seismic microzonation studies. This approach ean be used to display site effects and to identify different microzones taking different earthquake magnitudes and groundwater levels into account.

关键词： microzonation site effect visco-hypoplasticity non-linearity Bucharest Romania.

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.

Large Scale Mass Movements Triggered by the Kashmir Earthquake 2005,Pakistan

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Journal of Mountain Science 2014年第1期11卷 19-30页

作者： Muhammad BASHARAT joachim rohn Mirza Shahid BAIG Muhammad Rustam KHAN Markus SCHLEIER GeoZentrum Nordbayern Friedrich-Alexander-University Erlangen-Nuremberg Institute of Geology University of Azad Jammu and Kashmir

The SPOT image analysis in Muzaffarabad Azad Kashmir,northwest Himalayas,Pakistan reveals that the Kashmir earthquake 2005 triggered a number of coseismic mass movements along the hanging wall block of the Muzaffarabad *** Neelidandi and Langarpura rock falls have been identified as two major reactivated mass movements with an estimated volume of 3.1 × 106m3and 5.76 × 106m3,*** Neelidandi and Langarpura mass movements were initiated during earthquake in the direction of northwest-southeast extension and northeastsouthwest directed thrusting,*** Neelidandi rock fall occurred in sheared cherty dolomites and limestones of the Cambrian Muzaffarabad Formation,whereas the Langarpura rock fall occurred in alternating clays,shales,claystones,siltstones and sandstones of the Miocene Murree *** rock units along the fault are highly fractured and *** geotechnical maps and geological longitudinal profiles show the relationship between the geometrical characteristics and mechanism of these mass *** characteristics were analyzed according to the role of topographic,seismic,geological and tectonic *** steep topography,sheared rocks,lithology,coseismic uplift and strong ground shaking of the hanging wall block along Muzaffarabad Fault facilitated the gravity collapse of these mass movements.

关键词： Coseismic mass movements Himalayas Muzaffarabad Fault Geological and tectonic factors Earthquake Rock fall

基于等效黏弹性模型获取土体最大动剪模量的计算方法

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岩石力学与工程学报 2013年第S2期32卷 4082-4090页

作者：项伟江洎洧 joachim rohn 中国地质大学教育部长江三峡库区地质灾害研究中心湖北武汉430074 长江科学院水利部岩土力学与工程重点实验室湖北武汉430010 爱尔兰根纽伦堡大学应用地质系

土动力特性参数中,最大动剪切模量Gmax是定量描述土动力学本构最重要的参量之一,现有研究方法通常需较多参量及工程经验方能对其进行半定量的计算,但天然状态条件下土体的Gmax真值是唯一且确定的。为此,结合对土体动力学特性广泛适用性... 详细信息

土动力特性参数中,最大动剪切模量Gmax是定量描述土动力学本构最重要的参量之一,现有研究方法通常需较多参量及工程经验方能对其进行半定量的计算,但天然状态条件下土体的Gmax真值是唯一且确定的。为此,结合对土体动力学特性广泛适用性的基于等效黏弹性理论的修正Davidenkov模型,基于土动三轴试验,提出对该模型中的3个参量多元回归和对Gmax自适应逼近迭代的反分析算法,用于求取Gmax并得到本构方程中所需系数。研究表明:该算法在同时满足Davidenkov模型曲线三参数对测试数据拟合以及反算Gmax残差最小的双重计算约束条件下,对3类土样的动三轴测试数据进行拟合,在规避直接获取Gmax存在困难的情况下,顺利得到各测试样本的动本构模型。

关键词：土力学修正Davidenkov模型最大动剪模量Gmax 自适应逼近算法动力三轴测试

An easy approach to assess the susceptibility of a landslide by utilizing simple raster overlay methods: A case study on Huangtupo landslide(P.R. China)

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Journal of Mountain Science 2016年第10期13卷 1701-1710页

作者： Christian DUMPERTH joachim rohn Alexander FLEER WANG Jin-ge XIANG Wei Karsten ZIMMERMANN University of Erlangen-Nuremberg Department of Geology and Mineralogy Chair of Applied Geology Exploration and Geosurvey DMT Gmb H & Co. KG Department of Geosciences Chair of Soil Science and Geomorphology University of Tübingen Department of Geotechnical Engineering and Engineering Geology China University of GeosciencesWuhan

Semi qualitative index based methods using rankings and ratings are commonly used in susceptibility estimations over a wide area. However, generalized ranking and ratings are not applicable for one single landslide. This paper gives an easy and transferable approach to a susceptibility assessment of Huangtupo landslide(P.R. China), using raster addition without taking account for ranking and ratings. Slope, aspect, curvature, location and drainage buffer distance raster data sets have been obtained out of open source digital elevation models using ESRI's Arc GIS. These conditioning factor raster data sets have been translated into raster data sets including simple yes or no criteria, referring to triggering or not. Subsequently they have been added by raster math to acquire a simple raster overlay *** that this map is compared to initial displacement measurements, obtained by using a ground based synthetic aperture radar device. Acquired data is recalculated to a raster data set using the same spatial extent, to provide the possibility of comparison of the two raster data sets. The results reveal, that 76.35% of all measured movements occur in areas where raster cells include three or more conditioning factors, indicating that easy raster math operations can lead to satisfying results in local scale.

关键词： Landslide susceptibility Geographical Information System(GIS) Raster overlay Huangtupo Radar interferometry

基于三维形态空间分析和仿真试验的岩体结构面剪切强度参数研究

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岩石力学与工程学报 2012年第10期31卷 2127-2138页

作者：江洎洧项伟 joachim rohn 姚远长江科学院水利部岩土力学与工程重点实验室湖北武汉430010 中国地质大学工程学院湖北武汉430074 埃尔朗根-纽伦堡大学应用地质系德国埃尔朗根91054

获取结构面可靠的强度指标是研究岩体强度的重要基础。因不同结构面样本的巨大差异,以及剪切测试难以重复进行的实际情况,直接通过试验获取剪切参数通常难度较大且结果不理想。以具有定向变形特征的岩体剪切结构面为研究对象,探索性提... 详细信息

获取结构面可靠的强度指标是研究岩体强度的重要基础。因不同结构面样本的巨大差异,以及剪切测试难以重复进行的实际情况,直接通过试验获取剪切参数通常难度较大且结果不理想。以具有定向变形特征的岩体剪切结构面为研究对象,探索性提出采用结构面剪切测试-结构面表面形态三维空间分析-数值仿真试验相结合方法,获取真实可靠的结构面强度参数。该方法优势表现为:岩体结构面摩擦角的2个组成部分即基本摩擦角和爬坡角完全分离,且能考虑结构面形态三维特性及剪切变形方向特征;同时,力学测试和数值试验结合,克服了单纯依靠剪切测试无法重复的重大难题。

关键词：岩石力学岩体结构面剪切强度参数结构面剪切测试三维空间分析数值试验

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.

三峡库区黄土坡临江滑坡体水岩(土)相互作用机理

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岩土工程学报 2012年第7期34卷 1209-1216页

作者：江洎洧项伟曾雯 joachim rohn 姚远中国地质大学教育部长江三峡库区地质灾害研究中心湖北武汉430074 长江科学院水利部岩土力学与工程重点实验室湖北武汉430010 Department of Applied Geology University Erlangen-Nuremberg Erlangengermany91054

水岩(土)相互作用与滑坡地质灾害的形成密切相关。选取仍处于变形阶段的三峡库区黄土坡临江滑坡体为研究对象,以从滑坡不同部位采集的8类滑坡不良地质体(包括滑带土、软弱层、软岩等)为研究样本,追踪测试各样本的矿物类型及含量、化学... 详细信息

水岩(土)相互作用与滑坡地质灾害的形成密切相关。选取仍处于变形阶段的三峡库区黄土坡临江滑坡体为研究对象,以从滑坡不同部位采集的8类滑坡不良地质体(包括滑带土、软弱层、软岩等)为研究样本,追踪测试各样本的矿物类型及含量、化学组分及颗粒级配等指标。经分析,各类不良地质体之间具有明显的同源性特征,在水岩(土)相互作用下,主要滑坡不良地质体的成因及转化过程得以清晰呈现。随后,另取主滑带附近垂直方向上的岩土体样本为例,结合试验数据,深入分析并直观展现了水岩(土)相互作用对岩土体微观结构和力学性能弱化的影响。本研究深入探讨了黄土坡临江滑坡体中的水岩(土)相互作用机理,研究成果对于了解相似滑坡灾害的形成过程和有针对性制定滑坡防治方案具有重要参考价值。

关键词：三峡库区水岩(土)相互作用滑坡不良地质体黏土矿物同源性