降雨型浅层黄土滑坡危险性评价与区划

黄土高原是我国地质灾害最为发育的地区之一,其中降雨诱发的浅层黄土滑坡又最为典型。以典型黄土地貌区-柳林县为例,应用SINMAP模型,探讨模型在黄土地区的适用性,分析了随着研究区内降雨量的增加,滑坡变形失稳区域的面积变化、分布位置和扩展趋势。研究表明,随着降雨量的增加,滑坡所处位置逐渐由稳定状态向失稳状态发展,位于失稳分区的滑坡数量逐渐增加,说明降雨对该研究区的斜坡稳定性影响较为明显。通过将模拟结果与实际发生的由降雨触发的滑坡灾害进行对比分析,可以得出SINMAP模型在黄土地区,对区域性降雨诱发浅层黄土滑坡稳定性的模拟预测有效,可以用于黄土地区浅层滑坡的稳定性评价研究。     

哀牢山芭蕉树滑坡地质力学模型及诱因分析

芭蕉树滑坡位于云南省哀牢山东麓,发生于2002年8月14日。本文详细介绍了芭蕉树滑坡的基本工程地质特征,并由此概化出滑坡形成的地质力学模型;应用极限平衡法对天然状态及暴雨状态下斜坡的稳定性进行了分析研究。分析结果表明芭蕉树斜坡在不考虑暴雨作用下处于稳定状态,而在暴雨触发作用下将失稳滑动。     

基于系统动力学的卸加载响应比参数及其在堆积层滑坡稳定性评价中的应用

针对堆积层滑坡的物质组成和力学性质,从系统动力学角度,提出以卸加载响应比作为滑坡稳定性评价参数,并对卸加载响应比参数与加卸载响应比参数进行了比较和分析,指出卸加载响应比参数在边坡的稳定性评价和工程实践中更具有理论意义和实际应用价值。通过论证分析,确定了构成卸加载响应比的卸加载参数和卸加载响应参数,并论证了其合理性与可行性,在此基础上建立了月降雨量-位移加速度卸加载响应比模型。并以新滩典型堆积层滑坡为例,运用该模型进行分析计算,发现卸加载响应比时序曲线所反映的稳定状态与滑坡的实际状况基本吻合,当Y' Y'-且Y'0时,滑坡整体失稳,说明卸加载响应比参数和评价模型用于预测滑坡的变形阶段和作为失稳判据是行之有效的。     

基于修正Green-Ampt模型的降雨诱发区域浅层斜坡失稳灾害分析

由于具有类似的工程地质和水文地质条件,在高度相关的降雨作用下,同一个区域中的降雨诱发浅层斜坡失稳灾害常成群出现.在区域尺度预测浅层斜坡失稳灾害对滑坡灾害的防灾减灾工作具有重要的意义.为此,提出了一种基于力学原理的降雨诱发浅层斜坡失稳灾害预测新模型RARIL.该模型采用修正Green-Ampt模型进行降雨入渗分析,采用无...     

三峡水库区兴山县电厂滑坡Ⅰ成因与稳定性

在研究了三峡水库区兴山县电厂滑坡Ⅰ的工程地质及滑坡体基本特征的基础上,介绍了该滑坡的结构及变形特征。从滑坡形成条件、诱发变形因素两方面分析了滑坡形成的原因及诱发坡体失稳的主要因素;在诱发因素分析的基础上应用中国地质大学(武汉)研发的LaSa软件程序,对电厂滑坡Ⅰ进行稳定性分析计算。结果表明:在天然情况下,滑坡整体均处于稳定状态;在特定条件情况下,滑坡处于临界蠕滑或失稳状态。结合工程实际对滑坡治理进行初步研究,提出了一些可行的防治措施及建议。     

边坡稳定性的神经网络预测研究

根据神经网络法的基本原理，结合38个实际边坡工程稳定实例，应用VB5．0可视化编程语言，建立了边坡稳定性的神经网络预测模型，并运用该模型对部分边坡工程的稳定性进行预测，预测结果与边坡实际稳定状态相吻合，从而表明了神经网络法在边坡稳定性预测中的有效性。     

志城顺层岩质边坡滑移破坏模型及变形范围探究

志城滑坡是西南山区典型的由于人工切坡形成的顺层高边坡,大部分边坡浅部已出现顺层滑坡现象,且前缘边坡开挖仍未达到设计标高,存在诱发潜在深层较大规模滑坡的可能。本文以该边坡为研究对象,对志城滑坡及潜在边坡的工程地质条件进行深入分析,探究其破坏成因机制,建立变形破坏机制的概念模型,认为该边坡可归结典型的滑移-拉裂变形破坏模式;在此基础上采用理论模拟计算边坡的顺层滑移范围与实际已发生的变形范围进行比较分析,评价结果认为该边坡失稳破坏范围并非通常认识的"一滑到顶"概念,并预测分析了潜在边坡的破坏失稳范围,进而提出合理工程治理范围。     

甘洛县阿尔铺子纵二路边坡破坏模式分析及防治对策

以甘洛县阿尔铺子纵二路边坡为例,对纵二路K0+110至K0+300路段开挖边坡的工程地质条件及斜坡的成因类型进行了调查研究,分析了该段边坡的破坏模式,并采用折线型传递系数法对其稳定性进行了评价。研究表明：(1)纵二路边坡为土质开挖边坡,最大开挖高度为11m,边坡所在斜坡为一古滑坡体,开挖边坡后破坏模式主要表现为高陡边坡沿基覆界面滑动,以边坡坡脚为剪出口剪出,形成整体破坏;(2)采用折线型传递系数法对该边坡进行稳定性评价,斜坡整体处于欠稳定至基本稳定状态,但开挖后临空面较高,土压力较大,判定各剖面开挖后前缘土体均处于不稳定状态;(3)在边坡防治设计时,不仅要考虑前缘土体因开挖产生的主动土压力,还应考虑整个后山斜坡因开挖失稳产生的滑坡推力,取其最大值进行设计,根据开挖前后边坡稳定性发展趋势,结合灾害与工程安全等因素,建议采用桩板挡土墙进行治理。     

倾斜基底高填方次生滑坡及其防治

本文在野外工程地质调查与岩土工程勘察的基础上,采用定性、定量分析方法,分析了堆放于陡坡上的高填方边坡产生滑坡的机理、类型及特征,研究表明该滑坡的类型属土质、中厚层、推移式次生滑坡。滑坡整体处于基本稳定状态,但稳定安全储备不高;在连续降雨或暴雨条件下该滑坡整体超过临界状态而处于不稳定状态,此时,滑坡可能产生失稳滑动破坏,对临近边坡处的人员及建筑物产生危害。建议采取抗滑桩、排水等综合治理方案,并对滑坡体进行监测。     

志城顺层岩质边坡滑移破坏模型及变形范围探究

志城滑坡是西南山区典型的由于人工切坡形成的顺层高边坡,大部分边坡浅部已出现顺层滑坡现象,且前缘边坡开挖仍未达到设计标高,存在诱发潜在深层较大规模滑坡的可能。本文以该边坡为研究对象,对志城滑坡及潜在边坡的工程地质条件进行深入分析,探究其破坏成因机制,建立变形破坏机制的概念模型,认为该边坡可归结典型的滑移-拉裂变形破坏模式;在此基础上采用理论模拟计算边坡的顺层滑移范围与实际已发生的变形范围进行比较分析,评价结果认为该边坡失稳破坏范围并非通常认识的"一滑到顶"概念,并预测分析了潜在边坡的破坏失稳范围,进而提出合理工程治理范围。     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

HYDROGEOLOGY

正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),     

SERIALS

正~~     

GEOPHYSICAL EXPLORATION

正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-     

QUATERNARY GEOLOGY & GEOMORPHOLOGY

正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-     

PETROLEUM GEOLOGY

正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)