含软弱夹层库岸滑坡滑带发育特征研究

本文分析了巴东新城区巴东组第3段岩体中软弱夹层的分布特征、滑坡滑带的发育特征,结果表明巴东组第3段岩体中发育的滑坡滑带可与原岩中的软弱夹层对应,软弱夹层受构造剪切和地下水泥化作用发育成以碎石夹泥或黏土夹碎石为主的滑带.分析认为黄土坡滑坡、赵树岭滑坡的深层变形与巴东组第3段次级褶皱发育、层间劈理密集导致岩体破碎有关,而两...     

GIS based landslide susceptibility mapping of Tevankarai Ar sub-watershed, Kodaikkanal, India using binary logistic regression analysis

Landslide susceptibility mapping is the first step in regional hazard management as it helps to understand the spatial distribution of the probability of slope failure in an area.An attempt is made to map the landslide susceptibility in Tevankarai Ar subwatershed,Kodaikkanal,India using binary logistic regression analysis.Geographic Information System is used to prepare the database of the predictor variables and landslide inventory map,which is used to build the spatial model of landslide susceptibility.The model describes the relationship between the dependent variable(presence and absence of landslide) and the independent variables selected for study(predictor variables) by the best fitting function.A forward stepwise logistic regression model using maximum likelihood estimation is used in the regression analysis.An inventory of 84 landslides and cells within a buffer distance of 10m around the landslide is used as the dependent variable.Relief,slope,aspect,plan curvature,profile curvature,land use,soil,topographic wetness index,proximity to roads and proximity to lineaments are taken as independent variables.The constant and the coefficient of the predictor variable retained by the regression model are used to calculate the probability of slope failure and analyze the effect of each predictor variable on landslide occurrence in thestudy area.The model shows that the most significant parameter contributing to landslides is slope.The other significant parameters are profile curvature,soil,road,wetness index and relief.The predictive logistic regression model is validated using temporal validation data-set of known landslide locations and shows an accuracy of 85.29 %.     

"钻孔注浆+预应力锚索"对破碎地层滑坡的治理

"钻孔注浆+预应力锚索"工艺被应用在了迪庆变电站滑坡山体的工程治理中.本文在分析滑坡体地层结构、岩性和地形特征的基础上,介绍工程设计、工艺和施工方案.工程效果表明,在破碎岩土区,"钻孔注浆+预应力锚索"工艺治理滑坡效果显著.     

北京市戒台寺滑坡稳定性评价及预警模型研究

在综合分析北京市戒台寺滑坡地质条件的基础上,对滑坡进行稳定性评价,建立了预警模型。     

The Monagas Fold-Thrust belt of Eastern Venezuela. Part II: Structural and palaeo-geographic controls on the turbidite reservoir potential of the middle Miocene foreland sequence

This paper presents a new structural-stratigraphic approach to constrain the reservoir potential of the middle Miocene turbidite systems within the Monagas Fold-Thrust Belt (MFTB) and Maturín Sub-Basin (MSB) of eastern Venezuela. In the frontal anticline structures of the MFTB (Amarilis Area) light hydrocarbons have been produced from these turbidite systems which were deposited in a foreland basin with a complex tectonostratigraphic evolution.In order to predict the location of other analogous reservoirs we used the structural model presented in Part I (Parra et al., 2010) to developed a palaeo-topographic reconstruction at early-middle Miocene. We have then used this reconstruction to constrain the palaeogeography of the middle Miocene foredeep where the turbidites were deposited. The area considered has 5000 km².By middle Miocene four regions are identified: 1) The southern basin margin dipped 1.5-2.5° north; 2) The foredeep axis had a southwest-northeast orientation. Within the foredeep the proto-structures of the MFTB created submerged highs that control the distribution of sediments; 3) The northern basin margin dipped 3-4° south; the coastline was controlled by the Pirital thrust sheet; 4) The main source of sediments was located towards the northwest on the Pirital thrust sheet and Serranía del Interior.Variations in shortening across the strike of the Pirital thrust were accommodated by a lateral ramp which controlled the location of a valley that acted as the main sediment pathway for the sediments that fed the turbidite system. This relationship between the thrust belt geomorphology and the location of turbidite sediment within the foredeep must be considered in order to assess the distribution of the Miocene turbidite reservoirs.     

Quantitative risk assessment of landslide by limit analysis and random fields

Risk may be estimated by multiplying the probability of failure by the consequence. This is acceptable for systems that have a single mode of failure. For systems that have multiple failure modes, such as landslides, the consequences should be assessed individually for each of the failure modes. This paper proposes a new framework of quantitative landslide risk assessment, in which consequences are assessed individually. The framework is generally applicable, and the landslide risk assessments of two typical slopes are presented.     

GPS滑坡位移监测精度影响因素简析

GPS位移监测技术已被广泛用于滑坡地质灾害监测预警工作中。三峡库区典型滑坡以GPS监测数据、野外踏勘和深部位移等资料为基础,对GPS监测影响进行研究,结果表明：监测点尤其是基准点被遮挡,采集到的数据存在严重误差,对滑坡变形分析影响巨大。     

滑坡危险性分析中地震动的概率性估算及地震滑坡的危险性评判

论述了滑坡危险性分析中如何科学地估算地震力的问题。主要思路概括为：将滑坡体视为一个完整体系的结构物（或震动对象）,将滑坡场点视为一个工程场点,利用比较成熟的地震危险性概率分析方法计算滑坡体未来若干年内可能遭遇的不同超越概率水平下的地震峰值加速度,这种不确定性的地震加速度是由地震预报的不确定性带入的,由此计算地震力和惯性力。最后,对地震触发滑坡的机理展开讨论。     

Deterministic sensitivity analysis for a model for flow in porous media

A deterministic method for sensitivity analysis is developed and applied to a mathematical model for the simulation of flow in porous media. The method is based on the singular value decomposition (SVD) of the Jacobian matrix of the model. It is a local approach to sensitivity analysis providing a hierarchical classification of the directions in both the input space and of those in the output space reflecting the degree of sensitiveness of the latter to the former. Its low computational cost, in comparison with that of statistical approaches, allows the study of the variability of the results of the sensitivity analysis due to the variations of the input parameters of the model, and thus it can provide a quality criterion for the validity of more classical probabilistic global approaches. For the example treated here, however, this variability is weak, and deterministic and statistical methods yield similar sensitivity results.     

Empirically-based modeling of spatial sampling uncertainties associated with rainfall measurements by rain gauges

In the quantitative evaluation of radar-rainfall products (maps), rain gauge data are generally used as a good approximation of the true ground rainfall. However, rain gauges provide accurate measurements for a specific location, while radar estimates represent areal averages. Because these sampling discrepancies could introduce noise into the comparisons between these two sensors, they need to be accounted for. In this study, the spatial sampling error is defined as the ratio between the measurements by a single rain gauge and the true areal rainfall, defined as the value obtained by averaging the measurements by an adequate number of gauges within a pixel. Using a non-parametric scheme, the authors characterize its full statistical distribution for several spatial (4, 16 and 36 km²) and temporal (15 min and hourly) scales.