共查询到19条相似文献，搜索用时 125 毫秒
1.
2.
3.
4.
《山地学报》2017,(2)
坡脚开挖、坡面堆载、不合理灌溉等人类活动诱发的工程性黄土滑坡灾害频频发生,对于当地居民的生命财产安全构成极大威胁。本文以兰州市沙井驿滑坡为研究对象,在工程地质勘测的基础上,研究滑坡的基本特征及导致滑坡发生的关键因素。通过减围压三轴试验研究黄土边坡开挖过程中土体的变形破坏特征。基于FLAC3D数值模拟方法,对黄土边坡的开挖过程进行模拟,分析开挖过程中边坡不同深度的土体应力及变形发展规律,揭示开挖过程中坡体稳定性变化规律及滑坡启动机理。结果表明,沙井驿滑坡是由于坡脚不合理开挖导致老滑坡复活,为牵引式滑坡;在开挖过程中,坡体内发生应力重分布,应力状态不断发生变化,随着开挖的进行,坡体变形逐渐增大;开挖结束后,坡体中部产生大量剪切裂缝,后缘产生张拉裂缝,坡体稳定性降至最低,中上部均有较大变形,最后发生失稳。 相似文献
5.
2010-07-27凌晨,四川省汉源县万工集镇后山因持续暴雨而突发高位高速远程滑坡-碎屑流,最大滑程约1.4 km,启动时滑坡体约48×104m3,沿线裹挟和铲刮沟谷及其两侧边坡松散体,到达坡脚部位滑坡碎屑流体积增大至100×104m3,最终导致沿沟的双合村一组5户20名村民失踪及下游万工集镇部分房屋被掩埋而倾倒破坏。滑坡启动区发育于万工集镇后侧二蛮山大沟内,沟左侧为二叠系灰岩(P1y),顺坡倾向沟内;右侧为强风化的二叠系峨眉山玄武岩(P2β),节理极发育;沟内早期堆积物丰富,特别是沟上游还存在一大型古滑坡体;这些不稳定物源在有利地形条件及降雨诱发下极易形成滑坡。原始沟谷上游高位陡峭地形导致山体具备高位潜在势能,具备形成高位高速远程滑坡-碎屑流的地形条件。2010-07-24—26的降雨是触发此起特大灾害的主要原因,累计降雨量达163 mm,在水的作用下启程剧动并高速下滑。采用将今论古的地质方法,从地质构造、地层序列、岩体坡体结构及坡体变形等角度研究了二蛮山滑坡孕育的地质演化史,再现了滑坡区域历史时期中重要的地质活动过程。 相似文献
6.
鬼招手滑坡位于“5·12”汶川地震极重灾区彭州市内,是地震4a后暴雨诱发的高速滑坡.剖析了主滑体和堆积区Ⅰ、Ⅱ、Ⅲ的特征;分析了影响该边坡稳定性并诱发滑坡的6大因素,包括地层岩性、河流及泥石流冲刷掏蚀坡脚、暴雨及雨水下渗、断裂及“5.12”汶川地震、地貌、人类工程活动,其中持续暴雨是滑坡主要诱发因素;计算了主滑体抛射初速度为40.41 m/s,运动距离为137m,定义了主滑体的破坏模式为滑移-抛射模式;总结了滑坡的破坏过程,分为坡体累积破坏、坡体启动、坡体运动、坡体堆积稳定4个阶段;对比分析了暴雨和地震诱发的高速滑坡的不同之处,对于地震灾区的防灾减灾工作具有一定参考价值. 相似文献
7.
8.
先锋村滑坡位于一凹形逆向古滑塌体上,其平面形态呈不规则扇形,剖面形态上呈台阶状。滑坡总体地势上呈西高东低,滑坡体上共分布1#、2#、3#、4#、5#、6#共六个次级滑坡体。滑坡危害对象等级为一级,危害程度为特大级。先锋村滑坡治理工程方案采用分期分区思路实施,一期治理区域为2#次级滑坡前缘、4#次级滑坡前缘、古滑坡前缘及1#、3#、6#次级滑坡范围,二期治理区域为2#和4#次级滑坡中部及古滑坡中部范围。研究成果对防灾减灾具有很重要的参考价值。 相似文献
9.
10.
采用工程地质钻探、物探、地质测绘及室内试验等技术方法探讨飞鹅山Ⅲ号滑坡形成机理与防治技术。结果表明：1）滑坡体主要岩性为泥质粉砂岩,飞鹅山滑坡属于新形成的深层中型牵引式滑坡,在平面上呈圈椅状。2）滑坡属于双层滑面滑坡,主滑面以中型深层滑坡为主,主滑体上部发育中型中厚层滑坡。3）滑坡产生的原因为：(1)泥质粉砂岩倾向与坡向基本一致,且岩层倾角为中等倾角;(2)人工开挖使坡脚形成高陡临空面,抗滑力大为降低;(3)雨水沿层面及节理裂隙入渗至坡体深部,大大增加岩土体容重,同时泥质粉砂岩遇水软化,抗剪强度显著降低。4）结合该滑坡区地质环境条件,采用坡面削坡+锚杆（索）+格构梁+双排预应力锚拉抗滑桩+三维网植草绿化+截排水+毛石挡墙的综合治理方法进行防治,监测结果显示该滑坡变形及位移已得到有效控制,整治效果良好。 相似文献
11.
滑坡稳定性判别的非计算方法 总被引：2，自引：6，他引：2
用计算来确定滑坡的稳定性，由于参数选取存不确定因素，就必然导致了其计算结果的不确定性。而滑坡稳定性判别的非计算方法，是通过对滑坡发育程度、形成条件的综合分析来确定滑坡的稳定程度的方法。文中通过归纳分析波坡的形成条件，然后从滑坡地貌条件、动力作用、堆积物特征、诱发因素等方面详细阐述了滑坡稳定性判别的方法，最后，例举了川藏公路102滑坡实例对该方法进行了验证。实践证明该方法是滑坡稳定性中非常实用和有效的方法。 相似文献
12.
张溪滑坡--台风诱发滑坡成因分析 总被引：6，自引：1，他引：5
14号台风“云娜”造成我国东部沿海地区发生多处滑坡地质灾害,张溪滑坡便是其中个案。通过对张溪滑坡成因进行分析,得出了张溪滑坡是在一定厚度覆盖层、特定地形条件、植被条件下,台风风力加载作用及暴雨的淘蚀、软化、增重等一系列过程共同作用下滑动失稳的滑坡。它与暴雨型滑坡的形成机理有显著不同,这一分析成果对类似滑坡的研究和防治具有一定的意义。 相似文献
13.
14.
斜坡类型描述岩层产状与斜坡的角度关系,很大程度上决定了斜坡岩土体变形的方式和强度,对地质灾害分布具有重要作用。斜坡的顺向坡、反向坡与地形的阳坡、阴坡概念相似,可以利用改进的太阳辐射地形因子计算模型(TOBIA指数)对斜坡类型进行定量化表达。计算TOBIA指数需要斜坡坡度、坡向、岩层倾角、倾向4个参数。以三峡库区顺向坡基岩滑坡多发地段青干河流域为例,通过区域地质图上产状点获取离散岩层倾角和倾向数值,经空间插值得到空间连续分布的倾角和倾向参数;通过数字高程模型获取坡度和坡向参数,得到区内TOBIA指数分布。在此基础上进一步研究指数和滑坡发育关系。结果表明,TOBIA指数值与区内斜坡类型密切相关,根据TOBIA指数值能很好地区分斜坡类型。以二分类变量逻辑回归模型对坡度和指数两个变量进行分析,发现引入TOBIA指数后,回归模型对已知滑坡拟合度由55%提高到71.5%,能有效提高区域滑坡灾害危险性区划结果精度。 相似文献
15.
基于专家知识的滑坡危险性模糊评估方法 总被引：6，自引：0，他引：6
滑坡发生的影响因素众多, 其危险性与各因素之间的关系多呈非线性关系, 同时各因素之 间也存在或强或弱的相关性, 而目前的危险性评价方法难以体现这些要求。本文提出了一种借助 滑坡专家知识并利用模糊推理理论进行滑坡危险性评价的方法。该方法通过建立了①坡度与岩 层倾角之差和坡向与岩层倾向之差、②坡度和岩性、③临空面和岩性、④坡形和岩性等四种环境 因子组合, 以此将不同环境因子之间的相关性融入各组合模型中, 并将四种组合所得的模糊危险 度进行叠加用于滑坡危险度的模糊评价。环境组合模型中的参数利用专家经验给出。将该方法应 用于三峡库区云阳- 巫山段, 得到了滑坡危险性的分级分布图。从滑坡危险性分布图上可清楚发 现, 本方法所计算出的危险性值在滑坡发生的地区明显高于未发生滑坡的地区, 该结果可以用于 城镇建设和重要基础规划设施的参考。 相似文献
16.
以自行研制的恒流式静态应变仪(中国专利号:88212764.0)为主机的HP-2型滑坡遥测系统,用作测值远传和分散设点集中遥测数据。本系统配接PC-1500A或IBM PC/XT计算机,可构成滑坡监测系统;它既能控制多点巡回检测、定点检测和通道号显示,亦可控制应变仪作半桥或全桥测量,又能控制采样时间等。1987—1990年运行结果表明,本遥测系统相当稳定可靠。 相似文献
17.
Comparison of landslide susceptibility based on a decision-tree model and actual landslide occurrence: The Akaishi Mountains, Japan 总被引：7，自引：0，他引：7
This paper proposes a statistical decision-tree model to analyze landslide susceptibility in a wide area of the Akaishi Mountains, Japan. The objectives of this study were to validate the decision-tree model by comparing landslide susceptibility and actual landslide occurrence, and to reveal the relationships among landslide occurrence, topography, and geology. Landslide susceptibility was examined through ensemble learning with a decision tree. Decision trees are advantageous in that estimation processes and order of important explanatory variables are explicitly represented by the tree structures. Topographic characteristics (elevation, slope angle, profile curvature, plan curvature, and dissection and undissection height) and geological data were used as the explanatory variables. These topographic characteristics were calculated from digital elevation models (DEMs). The objective variables were landslide occurrence and reactivation data between 1992 and 2002 that were depicted by satellite image analysis. Landslide susceptibility was validated by comparing actual data on landslides that occurred and reactivated after the model was constructed (between 2002 and 2004).This study revealed that, from 2002 to 2004, landslides tended to occur and reactivate in catchments with high landslide susceptibility. The landslide susceptibility map thus depicts the actual landslide occurrence and reactivation in the Akaishi Mountains. This result indicates that the decision-tree model has appropriate accuracy for estimating the probabilities of future landslides. The tree structure indicates that landslides occurred and reactivated frequently in the catchments that had an average slope angle exceeding ca. 29° and a mode of slope angle exceeding 33°, which agree well with previous studies. A decision tree also quantitatively expresses important explanatory variables at the higher order of the tree structure. 相似文献
18.
Pece V. Gorsevski Paul E. Gessler Jan Boll William J. Elliot Randy B. Foltz 《Geomorphology》2006,80(3-4):178-198
Mapping of landslide susceptibility in forested watersheds is important for management decisions. In forested watersheds, especially in mountainous areas, the spatial distribution of relevant parameters for landslide prediction is often unavailable. This paper presents a GIS-based modeling approach that includes representation of the uncertainty and variability inherent in parameters. In this approach, grid-based tools are used to integrate the Soil Moisture Routing (SMR) model and infinite slope model with probabilistic analysis. The SMR model is a daily water balance model that simulates the hydrology of forested watersheds by combining climate data, a digital elevation model, soil, and land use data. The infinite slope model is used for slope stability analysis and determining the factor of safety for a slope. Monte Carlo simulation is used to incorporate the variability of input parameters and account for uncertainties associated with the evaluation of landslide susceptibility. This integrated approach of dynamic slope stability analysis was applied to the 72-km2 Pete King watershed located in the Clearwater National Forest in north-central Idaho, USA, where landslides have occurred. A 30-year simulation was performed beginning with the existing vegetation covers that represented the watershed during the landslide year. Comparison of the GIS-based approach with existing models (FSmet and SHALSTAB) showed better precision of landslides based on the ratio of correctly identified landslides to susceptible areas. Analysis of landslide susceptibility showed that (1) the proportion of susceptible and non-susceptible cells changes spatially and temporally, (2) changed cells were a function of effective precipitation and soil storage amount, and (3) cell stability increased over time especially for clear-cut areas as root strength increased and vegetation transitioned to regenerated forest. Our modeling results showed that landslide susceptibility is strongly influenced by natural processes and human activities in space and time; while results from simulated outputs show the potential for decision-making in effective forest planning by using various management scenarios and controlling factors that influence landslide susceptibility. Such a process-based tool could be used to deal with real-dynamic systems to help decision-makers to answer complex landslide susceptibility questions. 相似文献
19.
T. L. Gipprich R. K. Snieder R. W. Jibson W. Kimman 《Geophysical Journal International》2008,172(2):770-778
Dynamic stresses generated by earthquakes can trigger landslides. Current methods of landslide analysis such as pseudo-static analysis and Newmark's method focus on the effects of earthquake accelerations on the landslide mass to characterize dynamic landslide behaviour. One limitation of these methods is their use Mohr–Coulomb failure criteria, which only accounts for shear failure, but the role of tensile failure is not accounted for. We develop a limit-equilibrium model to investigate the dynamic stresses generated by a given ground motion due to a plane wave and use this model to assess the role of shear and tensile failure in the initiation of slope instability. We do so by incorporating a modified Griffith failure envelope, which combines shear and tensile failure into a single criterion. Tests of dynamic stresses in both homogeneous and layered slopes demonstrate that two modes of failure exist, tensile failure in the uppermost meters of a slope and shear failure at greater depth. Further, we derive equations that express the dynamic stress in the near-surface in the acceleration measured at the surface. These equations are used to approximately define the depth range for each mechanism of failure. The depths at which these failure mechanisms occur suggest that shear and tensile failure might collaborate in generating slope failure. 相似文献