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1.
滑坡受控于地质环境条件和坡体地质结构,不同地质结构的斜坡失稳破坏的模式存在差异,本文以后龙门山千枚岩区为例,基于现场调查,梳理总结了区内岩质滑坡发生的力学模式与斜坡地质环境、坡体结构之间的关系,进而选取控制滑坡发生的关键因素,运用ARCGIS软件的加权叠加功能定量划分了不同模式滑坡的易发区域,主要取得以下认识：（1）滑移—拉裂式滑坡主要发生在坡度30-45°的顺向飘倾坡内、滑移—溃曲式滑坡发生在坡度30-45°的顺向伏倾坡内、倾倒变形主要发生在岩层倾角大于65°的反向斜坡内;（2）区内倾倒变形易发区面积为8.73km2、滑移拉裂易发区面积为4.31m2、滑移溃曲易发区面积为3.28km2,以倾倒变形类型的滑坡为主,已发生滑坡与易发分区结果比对证明了滑坡易发分区与实际情况基本吻合。 相似文献
2.
基于粒子群优化支持向量机的延长县滑坡易发性评价 总被引：4，自引：0，他引：4
参数优化问题直接影响着支持向量机的预测精度和泛化能力,粒子群优化算法具有全局最优搜索能力,因此通过粒子群算法优化支持向量机参数可以有效提高预测精度。以延长县历史滑坡数据为基础,分析了岩性、地貌类型、土壤厚度、坡度、坡向、坡高与滑坡分布的关系,并利用滑坡密度值对各定性或定量因子进行了归一化处理;在此基础上,通过区域内所划分的16 300个斜坡单元作为评价单元,采用粒子群优化支持向量机(PSO-SVM)算法完成了延长县滑坡的易发性评价。从滑坡密度指标角度来看,评价结果中高易发区和极高易发区的历史滑坡数占比72.19%,通过滑坡面积百分比(LAR)等指标进行了有效的验证,均显示出对滑坡易发性评价效果良好。 相似文献
3.
2010年1月12日海地MW 7.0级地震触发了大量的滑坡。我们基于GIS与遥感技术构建了3类详细完备的海地地震滑坡编录图,分别为单体滑坡面分布数据,滑坡中心点位置数据与滑坡后壁点位置数据。结果表明海地地震触发了30828处滑坡,这些滑坡大致分布在一个面积为3192.85km2的区域内,滑坡覆盖面积为15.736km2。基于滑坡中心点密度(LCND)、滑坡后壁点密度(LTND)、滑坡面积百分比(LAP)与滑坡剥蚀厚度(LET)这4个衡量指标,使用统计分析方法,分析了海地地震滑坡及其剥蚀厚度与地震参数、地形参数、公路参数的关系。分析结果表明滑坡与坡度、地震动峰值加速度(PGA)存在大致的正相关关系; 与距离恩里基约芭蕉园断裂、距离水系存在大致的负相关关系; 滑坡沿着恩里基约芭蕉园断裂距离的统计结果表明,震中以西距离震中22~26km与8~12km的区域,与震中以东距离震中6~18km的区域是地震滑坡易发区域; 斜坡曲率值越接近0,也就是坡面较平的斜坡越不容易在地震条件下发生滑动; LCND、LTND、LAP与LET高值对应的高程区间为200~1200m; 滑坡发生的优势坡向为E方向; 滑坡的发生与距离震中、距离公路没有太明确的关系。 相似文献
4.
汶川地震滑坡与地震参数及地质地貌因素之间的相关关系 总被引：4，自引：0，他引：4
在对汶川地震诱发的典型滑坡进行野外调查和相关资料收集、分析和整理的基础上,对汶川地震滑坡与地震参数及坡度、岩土体特性等地质地貌因素之间的相关关系进行了统计分析。结果表明: (1)汶川地震滑坡主要发生在Ⅶ～Ⅺ烈度区, Ⅵ度及以下烈度区中发生的滑坡较少; (2)汶川地震滑坡主要发生在距震中300km的范围内,且距震中200km的范围内滑坡分布最为集中; (3)汶川地震滑坡的易发斜坡坡度为30～50,其中30～40是汶川地震滑坡发育最为敏感的坡度; (4)汶川地震滑坡主要发生在600～1500m的高程范围内,在600～1000m高程范围内的中低山和丘陵区滑坡分布最为集中; (5)砂泥岩、板岩、片岩、千枚岩等软岩类和土质类岩性是汶川地震滑坡的易发岩性,其次是软硬岩组合类,在统计的47个典型滑坡中,花岗岩、碳酸盐岩等硬岩类中发生的滑坡最少,而且由汶川地震直接导致复活的老滑坡也比较少。 相似文献
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2008年汶川地震滑坡详细编目及其空间分布规律分析 总被引：3，自引：0，他引：3
最新研究成果表明, 2008年5月12日汶川MS 8.0级地震触发了超过197000处滑坡。首先,基于GIS与遥感技术构建了汶川地震滑坡的3类编目图,分别为单体滑坡面分布数据、滑坡中心点位置和滑坡后壁点位置。构建方法为基于地震前后高分辨率遥感影像的目视解译方法,区分单体滑坡并圈定其边界,对滑坡后壁进行识别与定点,并开展了部分滑坡的野外验证工作。这些滑坡分布在一个面积大约为110000km2的区域内,滑坡总面积约为1160km2。选择一个面积约为44031km2的区域作为研究区,区内滑坡数量为196007个,滑坡面积为1150.622km2,这是最详细完整的汶川地震滑坡编录成果,也是单次地震事件触发滑坡最多的记录。其次,开展研究区内的地震滑坡空间分布规律的研究。基于滑坡面与滑坡中心点分别构建滑坡空间分布面积密度图与点密度图,结果表明:滑坡多沿着映秀北川断裂分布,多发生在断裂的上盘。滑坡的高密度区位于映秀北川同震地表破裂的南西段(映秀镇与北川县之间)的上盘区域,这一区域恰对应着逆冲分量为主的断裂上盘,表明逆冲断裂对上盘区域发生滑坡的极强烈的控制作用,而该区域正是形变最大的区域,因此说明是地震滑坡发生的强烈控制作用。基于滑坡面密度(LAP)、滑坡中心点密度(LCND)与滑坡后壁点密度(LTND)这3个衡量指标,使用统计分析方法,评价了汶川地震滑坡与地震参数、地质参数、地形参数的关系。结果表明:LAP、LCND与LTND这3个衡量指标与坡度、地震烈度与PGA存在明显的正相关关系; 与距离震中、距离映秀北川同震地表破裂存在负相关关系; 斜坡曲率越接近0,滑坡越不易发生; LAP、LCND与LTND的高值高程区间为1200～3000m; 滑坡发生的优势坡向为E、SE、S方向; 滑坡发育的易发岩性为砂岩与粉砂岩(Z)、花岗岩; 滑坡与坡位的相关关系不太明显。统计结果还表明LCND与LTND两个衡量指标的差异对地震与地质因子不敏感,而对地形因子较敏感。最后将本文的统计结果与以往的汶川地震滑坡空间分布规律统计成果进行了一些对比,对比结果表明,对于某些因子,如高程、岩性、距离震中、距离映秀北川断裂的统计分析结果,采用不完整的滑坡分布数据或点数据,与采用较完整的滑坡分布面数据会有一定的差异,这种差异并未出现在针对坡度与坡向等因子的统计对比结果中。总之,作者认为一个完备、详细的地震滑坡分布面要素编目图是地震滑坡空间分布规律定量分析、危险性定量分析与滑坡控制的地震区地貌演化研究的重要基础,否则,与实际情况相比,得到统计结果会有一定的偏差,本文的研究成果与以往成果的对比结果证明了这一点。 相似文献
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2013年7月22日,中国甘肃省岷县漳县交界地区发生MS6.6级地震。地震触发了大量的滑坡,主要类型为小型的黄土崖崩、滑、倾,还有一些深层连贯型滑坡、大型土质流滑、侧向滑移等地震滑坡类型。本文主要基于地震滑坡野外考察与高分辨卫星影像人工目视解译方法,开展本次地震触发滑坡的编录图制作工作,并基于编录成果开展地震滑坡空间分布规律分析工作。滑坡编录结果表明此次地震至少触发了2330处滑坡。基于GIS平台下开展了地震滑坡与地形控制因子、地质控制因子与地震控制因子的关系统计。结果表明岷县漳县地震滑坡受地形因子的控制作用较小; 受地层岩性的控制作用较大。其中1401处滑坡(占总滑坡的60.13%)分布在下伏基岩为古近系下统地层(Eb)砾岩与砂岩的区域内,其中滑坡密度是所有地层分类中最高的,达到22.78个km-2。地震滑坡与PGA的统计关系并不明显。地震滑坡主要集中在一个与发震断层走向一致的长条形区域内,长约14km,宽约5km。该区域内滑坡数量为1864个,占所有滑坡数量的80%,表明了岷县漳县地震滑坡空间分布的密集特征。文章获得的基于地震事件的区域滑坡编录成果是后续地震滑坡相关科学研究的重要基础与核心数据; 空间分布规律分析成果可为地震区滑坡与泥石流防灾减灾提供科学参考。 相似文献
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基于GIS与确定性系数分析方法的汶川地震滑坡易发性评价 总被引：4，自引：0，他引：4
汶川Ms 80级大地震诱发了数以万计的滑坡灾害。在大约48678 km2的滑坡影响区域内,作者采用震后遥感影像解译并结合野外调查的方法,共解译出48007处滑坡。应用GIS技术,建立了汶川地震诱发滑坡灾害及相关地形、地质空间数据库。采用地震滑坡确定性系数分析方法,分析了地震滑坡关于地震烈度、岩性、坡度、断层、高程、坡向、河流与公路等8个因素的易发程度。基于GIS栅格分析方法,分别对16种不同影响因子组合类型进行地震滑坡易发性评价。最后,应用AUC（Area Under Curve,评价曲线下面积）方法得到最佳因子组合及其对应的评价结果,使用自然分类法则方法将研究区按滑坡易发程度分为极高易发区、高易发区、中易发区、低易发区与极低易发区5类,极高易发区与高易发区面积之和约1169046km2,占研究区总面积的2402%,其中发育滑坡面积为52484 km2,占滑坡总面积的7373%。结果表明了极高与高易发区与实际滑坡之间有着良好的一致性,方法的评价结果成功率（AUC值）达到82107%。 相似文献
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5.12汶川地震崩塌滑坡分布特征及影响因子评价——以都江堰至汶川公路沿线为例 总被引：5，自引：2，他引：3
以都江堰至汶川公路沿线为研究对象,利用遥感影像解译和野外调查数据,探讨了都汶公路沿线地震崩塌滑坡分布规律,并利用主成分分析,确定了影响地震崩塌滑坡的关键影响因子.结果表明:①地震崩塌滑坡主要分布在坡度为30～65°的坡体上,其崩塌滑坡面积占总面积的82.79%;坡向为东、东南和南坡3个坡向, 其崩塌滑坡面积占总面积的51.32%;其分布的坡面粗糙度多为Ⅰ~Ⅳ级,其崩塌滑坡面积占总面积的84.45%;集中在距主断层距离5～20 km范围内,其崩塌滑坡面积占总面积的56.15%;土地利用类型主要为有林地、灌木林地和疏林地,尤其是灌木林地,三者的崩塌滑坡面积占总面积的89.93%;地层岩性主要为第1、2、3和20类地层岩性组合,其崩塌滑坡面积占总面积的41.34%.②根据主成分分析,坡度和坡面粗糙度对地震崩塌滑坡的贡献最大,是影响地震崩塌滑坡的关键因子,其次是距主断层距离和土地利用,坡向和地层岩性对地震崩塌滑坡的贡献程度较小. 相似文献
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鲜水河断裂带炉霍段具有极强的活动性,一旦发生地震,极有可能引发大量的滑坡等地质灾害。研究区发育1973年地震滑坡179个（通过现场调查识别出43个）,1973年以前地震滑坡62个。本文研究数据基于1973年179个及1973年以前62个地震滑坡,共计241个地震滑坡。利用统计分析方法研究了1973年179个地震滑坡分布与烈度及震中距的关系,分析了241个地震滑坡发育的滑动方向、地层岩性、地形坡度、相对高程及在断裂不同位置的分布特征。结果显示:（1）炉霍断裂地震滑坡规模以小型为主;（2）集中于Ⅸ～Ⅹ度烈度区内;（3）距震中0～5km及10～15km范围内密度最大;（4）滑动方向多与断裂斜交,交角介于35～75;（5）断裂南东段滑坡数量多于北西段,北东盘多于南西盘,北西段的北东盘滑坡个体面积较大;（6）滑坡多发育于T2-3r地层中;（7）主要分布于斜坡的中下部,相对高程主要介于30～60m;（8）发育坡度多介于30～45,具有规模越大,坡度越小的特点。 相似文献
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本文采用“双差地震定位法”重新定位了福建数字地震台网正式运行以来发生的水口库区附近的地震,结果表明,记录的地震分二个时段,分别发生于不同的小区域内1999年1月~12底,发生于N26.35°~N26.40°,E118.67°~E118.70°,约5×3km2范围内,震源深度集中在9~10km范围内,整个震源的分布为一近水平的南北展布,具有一定的构造地震特征;2000年初至2005年末,地震主要发生于N26.39°~N26.41°,E118.62°~E118.64°,约2×2km2范围内,震源深度约2~4km,由于记录的地震震级小、个数少、时间跨度大,认为应是浅表应力局部调整的结果。 相似文献
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S. Viswanathan K. Surya Prakash Rao B. Mahabaleswar 《Journal of the Geological Society of India》2013,82(6):621-627
Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours. 相似文献
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奥地利安东帕有限公司 《岩矿测试》2009,28(3):306-306
最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提 相似文献
14.
E. M. Prasolov S. A. Sergeev B. V. Belyatsky E. S. Bogomolov K. A. Gruzdov I. N. Kapitonov R. Sh. Krymsky V. O. Khalenev 《Geochemistry International》2018,56(1):46-64
This paper reports the first results of a study of 11 isotope systems (3He/4He, 40Ar/36Ar, 34S/32S, 65Cu/63Cu, 62Ni/60Ni, 87Sr/86Sr, 143Nd/144Nd, 206–208Pb/204Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others. 相似文献
15.
Mining induced subsidence can significantly affect mining costs where major surface facilities and natural environment need to be protected. Overburden grout injection is a technology used to control coal mine subsidence by injecting the mine waste material extracted from the coal back into the inter-burden rock during longwall mining. The flowing slurry is here categorised as a nonlinear viscous cohesive (Bingham plastic) fluid. During longwall mining the grout slurry is pumped into the separated beds of the rock mass through a central vertical borehole, which is drilled deep into the inter-burden rock strata above the coal seam. However, a blockage can occur in the injection system when the slurry velocity falls below a certain critical threshold velocity, indicating a material phase change from cohesive-viscous to cohesive-frictional. In situ field injection tests through boreholes have been simulated at a smaller scale at the CSIRO laboratory in Brisbane by pumping the slurry through a radial disk (gap = 4 mm) from its centre. Laboratory experiments indicate a general, nonlinear, cohesive, viscous, frictional model for shear behaviour of the slurry, in which the material shear parameters are functions of the disk radial distance. Complete dimensional and dimensionless analytical solutions have been developed based on an approach related to Bingham–Herschel–Bulkley fluid mechanics. The derived formulae include relations for minimum pump pressure, local pressure and pressure gradient, wall shear stress, volume rate, velocity and velocity gradient. The theoretical results match the experimental measurements. The experiments covered slurries with maximum particle sizes of 0.5 to 2 mm with about 50% being larger than 100 µm. The viscosities at the various solids concentrations were measured with a standard torsion viscometer. This study differs from the previous research in several distinct aspects, namely, consideration of the variable shear parameters rather than fixed values, inclusion of total nonlinear behaviour, and implementation of a friction function to mimic behaviour of the deposited and consolidating stiff slurry, which can cause a significant pressure rise as a result of the increased shear resistance. 相似文献
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17.
岩石密度和超高压岩石折返速率 总被引：1，自引：3，他引：1
在常温常压条件下对中国大陆科学钻CCSD主孔100-3000米岩心样品进行了密度测量,建立了密度连续剖面,并界定了不同超高压岩石的密度值。通过对比高温高压物性实验资料,岩石密度随着退变程度增强而降低,榴辉岩密度变化序列为3.52g/cm3→3.49g/cm3→3.07g/cm3→2.93g/cm3。超高压长英质岩石密度变化序列为3.00g/cm→2.80g/cm3→2.65g/cm3。上述实验资料是讨论不同折返阶段岩石所受浮力的基础,为研究折返速率大小提供了基本参数。本文通过折返板块运动平衡时,上浮力与粘滞力平衡这一关系式,定量研究了大陆俯冲板块的折返速率,认为密度差产生上浮力从而引起折返,温度对板块折返速率的影响最为显著;密度差大小、折返角度、折返板块大小对折返速率也有直接的影响。定量模拟分析表明,在温度高于850℃时,板块的折返速率可以超过100mm/a;当温度降至700℃时,折返速率则低于1.5mm/a。作者认为在折返早期,温度较高,板块快速折返至60-70km榴辉岩相深度;随着传导散热,温度降低,板块以较慢的速率折返至中下地壳。折返速率的估算表明,浮力是板块折返第一阶段(从>100km深部折返至<40km的中下地壳)的主要驱动力。 相似文献
18.
Alexander E. C. Broberg J. S. Kehren A. R. Graziani M. M. Turri W. L. 《Environmental Geology》1993,22(4):353-361
Bellechester, Minnesota, is a small community of approximately 155 residents located on the county line between Goodhue and Wabasha counties in southeast Minnesota's karst region. Bellechester is served by a 21-year-old wastewater treatment facility (WWTF) consisting of three waste-stabilization ponds. On 28 April 1992 six sinkholes were discovered to have drained cell 2 of the WWTF resulting in the loss of approximately 8.7×106 1 of partially treated effluent and about 600 m3 of soil into previously undetected subsurface voids of unknown dimensions. In the week following the collapse, approximately 200 water wells located within a 5-km radius of the WWTF were sampled in an after-the-fact, emergency sampling program. Twelve samples with elevated fecal coliform levels, 18 samples with nitrate-nitrogen greater than the 10 mg/1 standard, and no samples with elevated chlorides were found. However, the elevated levels could not be unambiguously attributed to the WWTF collapse. This is the third WWTF to fail by sinkhole collapse in southeast Minnesota since 1974. All three collapsed lagoons have been located in similar geomorphic and stratigraphic settings. However, at least two lagoons have collapsed in the adjacent area in northeast Iowa, and these lagoons are located at different stratigraphic positions. Twenty-two WWTFs constructed in southeast Minnesota's karst region in the last 25 years have been identified as subject to potential sinkhole collapse. An unknown but significant number of manure storage lagoons, flood control structures, etc., have also been constructed in the karst region and are at risk. Public agencies are beginning to develop plans to deal with the risk associated with existing and future waste lagoons in this environment. The critical hydrogeologic parameters that can be used to prioritize the risk of collapse at existing facilities include: (1) the lithology of the first bedrock beneath each lagoon, (2) the thickness of surficial materials between the lagoon and the bedrock surface, (3) the presence and construction of liners (seepage rate), and (4) the proximity to existing sinkholes. 相似文献
19.
Mercury,arsenic, antimony,and selenium contents of sediment from the Kuskokwim River,Bethel, Alaska,USA 总被引：1，自引：0，他引：1
The Kuskokwim River at Bethel, Alaska, drains a major mercury-antimony metallogenic province in its upper reaches and tributaries. Bethel (population 4000) is situated on the Kuskokwim floodplain and also draws its water supply from wells located in river-deposited sediment. A boring through overbank and floodplain sediment has provided material to establish a baseline datum for sediment-hosted heavy metals. Mercury (total), arsenic, antimony, and selenium contents were determined; aluminum was also determined and used as normalizing factor. The contents of the heavy metals were relatively constant with depth and do not reflect any potential enrichment from upstream contaminant sources. 相似文献
20.
滇东南锡、银、铅、锌多金属矿床主要分布在个旧、白牛厂、都龙3个矿区,而滇东南较大的3个花岗岩体又分别出露在3个矿区或附近.花岗岩体均形成于燕山晚期,岩石化学、矿物成分相似,富含锡、银、铅、锌、钨、铜等成矿元素.矿床主金属元素组合与岩体之间的距离由远而近出现由锡、钨、(铍、铌、钽)→锡、钨、(铁)、铜、铟→锡、铅、锌、银、铟、(锑)有规律的变化.花岗岩浆是成矿物质来源和成矿热源.岩浆侵入初期使上覆地层隆起产生背斜(凹陷部位成向斜);同时使地层产生一系列裂隙、压性断层或层间断裂;岩浆侵入晚期,这些断层再次活动,表现为张性,岩浆产生的含矿热液沿由其活动所造成的断裂迁移、充填、交代、沉淀而形成矿床. 相似文献