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1.
Slope failure or landslide is a complex geological/geotechnical problem that involves much uncertainty. In this work, a framework for probabilistic assessment of landslide is presented with a focus on the El Berrinche landslide, Honduras. One unique feature of this case study involving the El Berrinche landslide is that the stability analysis has to be carried out with limited data. Another challenge in this study is to assess possible remedial measures in a way that can easily be communicated to the government and the public. A reliability-based framework for a probabilistic assessment is proposed. With this approach, different levels of risk for landslide are assessed and the associated costs are estimated; and all information is integrated into the decision-making process for choosing a remedial action.  相似文献   

2.
A review of assessing landslide frequency for hazard zoning purposes   总被引:11,自引:0,他引:11  
The probability of occurrence is one of the key components of the risk equation. To assess this probability in landslide risk analysis, two different approaches have been traditionally used. In the first one, the occurrence of landslides is obtained by computing the probability of failure of a slope (or the reactivation of existing landslides). In the second one, which is the objective of this paper, the probability is obtained by means of the statistical analysis of past landslide events, specifically by the assessment of the past landslide frequency. In its turn, the temporal frequency of landslides may be determined based on the occurrence of landslides or from the recurrence of the landslide triggering events over a regional extent. Hazard assessment using frequency of landslides, which may be taken either individually or collectively, requires complete records of landslide events, which is difficult in some areas. Its main advantage is that it may be easily implemented for zoning. Frequency assessed from the recurrence of landslide triggers, does not require landslide series but it is necessary to establish reliable relations between the trigger, its magnitude and the occurrence of the landslides. The frequency of the landslide triggers can be directly used for landslide zoning. However, because it does not provide information on the spatial distribution of the potential landslides, it has to be combined with landslide susceptibility (spatial probability analysis) to perform landslide hazard zoning. Both the scale of work and availability of data affect the results of the landslide frequency and restrict the spatial resolution of frequency zoning as well. Magnitude–frequency relationships are fundamental elements for the quantitative assessment of both hazard and risk.  相似文献   

3.
The Dereköy landslide threatening the town of Dereköy, Konya, Turkey is investigated in order to assess and manage the associated risk. Dereköy town, located 12 km west of Konya city center, which is the second largest city in central Anatolia, has been extending due to the demand for new settlement places in Konya for the last decade. As most of the town is situated on the slopes of Meram river valley, on which the slope movements are observed, the risk of landslide has been increasing due to these new settlements. In this study, the landslide risk in Dereköy is assessed by following the so-called decision analytical procedure. The risk is defined by multiplication of hazard and consequences of the hazard. The hazard, which is the probability of slope failure, is computed by using the first-order second-moment (FOSM) method. The possible consequences of a landslide in Dereköy are analyzed and their costs are assessed relative to each other. A decision tree for choosing among the possible alternatives for reducing the risk is constructed in order to manage the risk.  相似文献   

4.
Landslide consequence analysis: a region-scale indicator-based methodology   总被引:1,自引:1,他引:0  
Consequence analysis is, together with hazard evaluation, one of the major steps of landslide risk assessment. However, a significant discrepancy exists between the number of published landslide hazard and landslide consequence studies. While various methodologies for regional-scale hazard assessment have been developed during the last decade, studies for estimating and visualising possible landslide consequences are still limited, and those existing are often difficult to apply in practice mainly because of the lack of data on the historical damage or on landslide damage functions. In this paper, an indicator-based GIS-aided methodology is proposed with an application to regional-scale consequence analysis. The index, called Potential Damage Index, allows describing, quantifying, valuing, totalizing and visualising different types of consequences. The method allows estimating the possible damage caused by landslides by combining weighted indicators reflecting the exposure of the elements at risk. Direct (physical injury, and structural and functional damage) and indirect (socio-economic impacts) consequences are individually analysed and subsequently combined to obtain a map of total consequences due to landsliding. Geographic visualisation of the index allows the delineation of the areas exposed to any type of possible impacts that could be combined with a corresponding map displaying landslide probability of occurrence. The method has been successfully applied to analyse the present consequences in the Barcelonnette Basin (South French Alps). These maps contribute to development of adequate land use and evacuation plans, and thus are important tools for local authorities and insurance companies.  相似文献   

5.
金沙江上游沃达滑坡自1985年开始出现变形,现今地表宏观变形迹象明显,存在进一步失稳滑动和堵江的风险。采用遥感解译、地面调查、工程地质钻探和综合监测等方法,分析了沃达滑坡空间结构和复活变形特征,阐明了滑坡潜在复活失稳模式,并采用经验公式计算分析了滑坡堵江危险性。结果表明:沃达滑坡为一特大型滑坡,体积约28.81×106 m3,推测其在晚更新世之前发生过大规模滑动;滑坡堆积体目前整体处于蠕滑变形阶段,局部处于加速变形阶段;复活变形范围主要集中在中前部,且呈现向后渐进变形破坏特征,复活区右侧变形比左侧强烈。滑坡存在浅层和深层两级滑面,平均埋深分别约15.0,25.5 m,相应地可能出现两种潜在失稳模式:滑坡强变形区沿浅层滑带滑动失稳时,形成的堵江堰塞坝高度约87.2 m;滑坡整体沿深层滑带滑动失稳时,形成的堵江堰塞坝高度约129.2 m。沃达滑坡存在形成滑坡-堵江-溃决-洪水链式灾害的危险性,建议进一步加强滑坡监测,针对性开展排水、加固等防治工程。  相似文献   

6.
Vaunat  Jean  Leroueil  Serge 《Natural Hazards》2002,26(1):81-107
The paper first recalls briefly a methodological framework to assess landslide hazard and risk analysis in terms of predisposition, triggering andrevealing factors. This framework, that reflects the mechanisms involved in the landslide, is based on the Geotechnical Characterisation of slope movements proposed by Vaunat et al. (1994) and Leroueil et al. (1996). The Geotechnical Characterisation can be schematized by a 3-D matrix having the following axes: types of movement; types ofmaterial; and the four stages of movement: pre-failure, failure, post-failure andreactivation. For each relevant element of this 3-D matrix, there is a characterisationsheet including: the controlling laws and parameters, the predisposition factors, thetriggering or aggravating factors, the revealing factors and the consequences of the movement. The paper focuses afterwards on the post-failure stage, which generallyis the most destructive, and on the mobility index. It is shown that this laterindex can be described as the product of sub-indices associated with failure, brittlenessof the material, ability of the soil to develop pore pressures, geometry of the moving soil mass and characteristics of the terrain. It is also shown how these aspectscan be incorporated into the Geotechnical characterisation of slope movements. This seems to provide a rational basis for examining slope movements at the post-failure stage and assessing associated risks.  相似文献   

7.
Quantitative analysis of consequences (in terms of expected monetary losses) induced by slow-moving landslide mechanisms to buildings or infrastructure networks is a key step in the landslide risk management framework. It can influence risk mitigation policies as well as help authorities in charge of land management in addressing/prioritizing interventions or restoration works. This kind of analysis generally requires multidisciplinary approaches, which cannot disregard a thorough knowledge of landslide mechanisms, and rich datasets that are seldom available as testified by the limited number of examples in the scientific literature. With reference to the well-documented case study of Lungro town (Calabria region, southern Italy)—severely affected by slow-moving landslides of different types—the present paper proposes and implements a multi-step procedure for monetary loss forecasting associated with different landslide kinematic/damage scenarios. Procedures to typify landslide mechanisms and physical vulnerability analysis, previously tested in the same area, are here appropriately merged to derive both kinematic and damage scenarios to the exposed buildings. Then, the outcomes are combined with economic data in order to forecast monetary loss at municipal scale. The proposed method and the obtained results, once further validated, could stand as reference case for other urban areas in similar geo-environmental contexts in order to derive useful information on expected direct consequences unless slow-moving landslide risk mitigation measures are taken.  相似文献   

8.
Hazard analysis of seismic submarine slope instability   总被引:1,自引:0,他引:1  
To assess the risk associated with a submarine landslide, one must estimate the probability of slope failure and its consequences. This paper proposes a procedure to estimate the probability of earthquake-induced submarine slope failure (hazard) based on probabilistic seismic hazard analyses, ground response analyses and advanced laboratory tests. The outcomes from these analyses are treated in a probabilistic framework, with analytical simulations using mathematical techniques such as the first-order reliability method, Monte Carlo simulation and Bayesian updating. Fragility curves of slope failure during the earthquake (co-seismic) and after the earthquake (post-seismic) were developed in this study, and were shown to provide a clear and well-organized procedure to estimate the annual failure probability of a submarine slope under earthquake loading.  相似文献   

9.
The benefits of quantitative risk assessments for landslide management have been discussed and illustrated in several publications. However, there still are some challenges in its application for low-probability, high-magnitude events. These challenges are associated with the difficulties in populating our models for risk calculations, which largely require the input of expert opinion. This paper presents a quantitative risk assessment to a very slow moving rock slope within a dam reservoir in the Province of British Columbia, Canada. The assessment is focused on the risk to the population in the vicinity of the dam and the populated areas downstream. Expert opinions quantified the slope failure probabilities in the order of 10?3 to 10?1 per year for the smallest failure scenario considered and less than 10?6 for a failure of the entire slope. However, these estimations are associated with high levels of uncertainty. Our approach starts with the calculation and assessment of the magnitude and probability of the potential slope failure consequences, minimizing the uncertainties associated with estimated slope failure probabilities. Then, these consequences and failure probabilities are combined to obtain a measure of risk. The uncertainty associated with the slope failure probabilities is managed by the estimation of plausible ranges for these. The calculated risk levels are then presented as ranges of values and assessed against adopted evaluation criteria. The consequence and risk assessment of the rock slope suggest that the risk to the population exposed in the vicinity of the dam and populated areas downstream is under adequate control. The probability of large consequence scenarios is extremely low, in the order of 10?7 chance of an event causing more than 100 fatalities. We propose an observational technique to assess changes in risk levels and decide when to update the risk management approach or deploy emergency measures. The technique is focused on the detection of changes in the slope deformation patterns that would indicate an increase in the potential failure volumes or an imminent failure. It can be considered an extension to the current early warning system in place, easy to implement and enhanced with the strength of the comprehensive analysis required for a quantitative risk assessment.  相似文献   

10.
Landslide risk assessment and management: an overview   总被引:29,自引:0,他引:29  
Landslides can result in enormous casualties and huge economic losses in mountainous regions. In order to mitigate landslide hazard effectively, new methodologies are required to develop a better understanding of landslide hazard and to make rational decisions on the allocation of funds for management of landslide risk. Recent advances in risk analysis and risk assessment are beginning to provide systematic and rigorous processes to enhance slope management. In recent years, risk analysis and assessment has become an important tool in addressing uncertainty inherent in landslide hazards.This article reviews recent advances in landslide risk assessment and management, and discusses the applicability of a variety of approaches to assessing landslide risk. Firstly, a framework for landslide risk assessment and management by which landslide risk can be reduced is proposed. This is followed by a critical review of the current state of research on assessing the probability of landsliding, runout behavior, and vulnerability. Effective management strategies for reducing economic and social losses due to landslides are described. Problems in landslide risk assessment and management are also examined.  相似文献   

11.
Cui  Qi  Zhang  Lulu  Chen  Xiangyu  Cao  Zijun  Wei  Xin  Zhang  Jie  Xu  Jiabao  Liu  Dongsheng  Du  Chunlan 《Acta Geotechnica》2022,17(10):4497-4514

Most previous studies on the quantitative risk assessment (QRA) of landslides focused on the probability of slope failure at the pre-failure stage and adopted empirical models for consequence analysis. The conventional approaches simplify the relationship between the pre-failure state and the post-failure behavior and cannot reasonably account for the effects of uncertainty on the entire landslide process. In this paper, an efficient QRA method that involves the direct simulation of the entire landslide process is proposed. A QRA formula that considers the probability of only those landslides that can impact the element at risk is used. The coupled Eulerian–Lagrangian method is used to simulate the entire landslide process and to identify slopes that can impact the element at risk and determine the failure consequences. The subset simulation method is adopted to efficiently estimate the probability of landslide impact, and parameter uncertainty is considered. Two case histories of landslides are investigated. First, the 2011 Baqiao loess landslide in Xi’an, China, is investigated, and the results of the proposed method are compared with those of the conventional approaches. Second, the proposed method is applied to assess the risk of the 2015 Ganjingzi landslide in the Three Gorges Reservoir. The effects of the risk mitigation works are also discussed.

  相似文献   

12.
在滑坡的易发性、危险性和风险评价中,评价指标的选取和定量化是非常关键的。目前国内外采取的主要方法是利用GIS工具提取地形、岩性、距河流或断层带的距离、土地类型、植被、降雨、河流密度等因子进行分析和计算。这些指标在滑坡易发性和危险性区划中得到了广泛应用并取得了丰硕的成果,但也有一些局限性,具体表现在3个方面:一是不能针对不同的滑坡类型提供不同的评价指标体系;二是提取的这些因子中在区域上有些是共性因子,如岩性、降雨等;三是尚未建立一个完整的风险评价指标体系。本次研究专门针对陕西北部地区广泛发育的一种称之为"黄土崩塌"的滑坡类型,运用国际上流行的滑坡风险管理理论,确定其风险评价总体指标体系;基于大量野外调查数据的统计规律,分析了黄土崩塌危险性的主要来源和影响危害性的主要因素,从失稳可能性评价指标、崩塌强度评价指标、承灾体评价指标和易损性评价指标4个方面共确定了16大类36个评价指标。该指标体系的构建可为进一步的陕北黄土地区斜坡单元崩塌灾害风险评价提供基础。  相似文献   

13.
Current flood protection policies in the Netherlands are based on design water levels. This concept does not allow for a proper evaluation of costs and benefits of flood protection. Hence, research is being carried out on the introduction of a flood risk approach, which looks into both the probability of flooding and the consequences of flooding. This research is being carried out within the framework of a major project called the Floris project (FLOod RISk in the Netherlands). To assess the probability of flooding the Floris project distinguishes different failure modes for dikes and structures within the dike ring. Based on a probabilistic analysis of both loads and resistance the probability of failure is determined for each failure mode. Subsequently the probabilities of failure for different failure modes and dike sections are integrated into an estimate of the probability of flooding of the dike ring as a whole. In addition the Floris project looks into the different consequences of flooding, specifically the economic damages and the number of casualties to be expected in case of flooding of a particular dike ring. The paper describes the approach in the Floris project to assess the flood risk of dike rings in the Netherlands. One of the characteristics of the Floris project is the explicit attention to different types of uncertainties in assessing the probability of flooding. The paper discusses the different starting-points adopted and presents an outline on how the Floris project will deal with uncertainties in the analysis of weak spots in a dike ring as well as in the cost benefit analysis of flood alleviation measures.  相似文献   

14.
Many large landslides in the crystalline schist region of Shikoku Island, Japan, are susceptible to intense rainfall. Through the use of on-site monitoring systems, the activity of landslides and their meteorological triggers can be assessed. Continuous high-intensity rainfall was found to play a key role in provoking landslide movement. This paper investigates the influence of intense rainfall on the activity of crystalline schist landslides by examining rainfall and displacement of four typical landslides. By defining and calculating the effective rainfall and the relative landslide displacement, the relationship between intense rainfall and rainfall-induced landslide movement was analysed. Results indicate that the intense rainfall-induced landslide movement can be correlated with the effective rainfall. From these results, two rainfall thresholds were identified for the landslide risk management of Shikoku Island.  相似文献   

15.
Calabria is one of the Italian regions mostly affected by mass movements. The case study of a densely populated neighborhood (Ianò) located in the central-western sector of Calabria is presented. The several landslides triggered in February 2010 caused heavy damages to the built area, infrastructures and productions of this neighborhood, and increased the risk for the inhabitants. The results obtained through field surveys, photo interpretation, analyses of rainfall data and of the urban fabric evolution, historical survey on the reports of the damages caused by landslides, have enabled to formulate hypotheses on the potential causes that triggered landslide events and produced severe consequences on the area. These results have revealed that almost all landslides of February 2010 are partial reactivations of pre-existing landslide deposits. Moreover, the analyses have indicated a critical role of cumulative rainfalls over an interval of 15 days. However, the severe damage framework is explained through an unplanned urbanization which took place across the years on an area characterized by a high level of instability per se. Some buildings have been erected in proximity of or within pre-existing landslide scarps; in other cases, buildings have been constructed even inside the landslide bodies.  相似文献   

16.
刘鑫  王宇  李典庆 《工程地质学报》2019,27(5):1078-1084
边坡失稳是涉及土体大变形的动态演化过程,该过程往往决定了滑坡失事后果。传统的边坡稳定分析方法如极限平衡方法与有限元方法难以模拟边坡失稳演化过程,尤其是失稳后的土体变形破坏过程。边坡失稳受到多重不确定性因素影响,其中一个重要因素是土体参数的空间分布不均匀性。在考虑土体参数的空间不均匀分布情况下,本文采用一种随机极限平衡-物质点法研究边坡不同破坏模式的动态演化过程,同时利用极限平衡方法简单、高效的优点和物质点方法模拟土体大变形破坏的能力。以一个两层不排水土坡算例为例,识别了4种不同的边坡破坏模式(即浅层、中层、深层和渐进),研究了它们的演化过程与土体参数的空间分布之间的关系。结果表明边坡的破坏模式演化过程与土体参数的空间分布密切相关,强调了岩土工程勘察信息对充分表征土体参数空间变异性的重要作用。  相似文献   

17.
Owing to fragile geo-morphology, extreme climatic conditions, and densely populated settlements and rapid development activities, West Java Province is the most landslide hazardous area in Indonesia. So, a landslide risk map for this province bears a great importance such as for land-use planning. It is however widely accepted that landslide risk analysis is often difficult because of the difficulties involved in landslide hazard assessment and estimation of consequences of future landslide events. For instance, lack of multi-temporal inventory map or records of triggering events is often a major problem in landslide hazard mapping. In this study, we propose a simple technique for converting a landslide susceptibility map into a landslide hazard map, which we have employed for landslide risk analysis in one ideally hazardous part of volcanic mountains in West Java Province. The susceptibility analysis was carried out through correlation between past landslides and eight spatial parameters related to instability, i.e. slope, aspect, relative relief, distance to river, geological units, soil type, land use and distance to road. The obtained susceptibility map was validated using cross-time technique, and was collaborated with the frequency-area statistics to respond to ‘when landslide will occur’ and ‘how large it will be’. As for the judgment of the consequences of future landslides, expert opinion was used considering available literature and characteristic of the study area. We have only considered economic loss in terms of physical damage of buildings, roads and agricultural lands for the landslide risk analysis. From this study, we understand the following: (1) the hazard map obtained from conversion of the susceptibility map gives spatial probability and the area of an expected landslide will be greater than 500m2 in the next 2 years, (2) the landslide risk map shows that 24% of the total area is in high risk; 30% in moderate risk; 45% in low risk and no risk covers only 1% of the total area, and (3) the loss will be high in agricultural lands, while it will be low in the road structures and buildings.  相似文献   

18.
A New Zealand Landslide Database has been developed to hold all of New Zealand’s landslide data and provide factual data for use in landslide hazard and risk assessment, including a probabilistic landslide hazard model for New Zealand, which is currently being developed by GNS Science. Design of a national Landslide Database for New Zealand required consideration of existing landslide data stored in a variety of digital formats and future data yet to be collected. Pre-existing landslide datasets were developed and populated with data reflecting the needs of the landslide or hazard project, and the database structures of the time. Bringing these data into a single database required a new structure capable of containing landslide information at a variety of scales and accuracy, with many different attributes. A unified data model was developed to enable the landslide database to be a repository for New Zealand landslides, irrespective of scale and method of capture. Along with landslide locations, the database may contain information on the timing of landslide events, the type of landslide, the triggering event, volume and area data, and impacts (consequences) for each landslide when this information is available. Information from contributing datasets include a variety of sources including aerial photograph interpretation, field reconnaissance and media accounts. There are currently 22,575 landslide records in the database that include point locations, polygons of landslide source and deposit areas, and linear landslide features. Access to all landslide data is provided with a web application accessible via the Internet. This web application has been developed in-house and is based on open-source software such as the underlying relational database (PostGIS) and the map generating Web Map Server (GeoServer). Future work is to develop automated data-upload routines and mobile applications to allow people to report landslides, adopting a consistent framework.  相似文献   

19.
在搜集和梳理全球一个多世纪以来灾难性工程滑坡实例的基础上,将人类工程活动诱发的滑坡分为4种基本类型和若干亚类:①采矿工程滑坡(包括地下采空型、露天采场型、尾矿坝及排土场型);②水利水电工程滑坡(包括库区岸坡型、水库大坝型、灌溉工程型);③线性基础设施工程滑坡(包括公路及铁路工程型、油气管道工程型);(鸯城市建设复合型工程滑坡。重点剖析了国内外著名的工程滑坡灾害案例,并兼顾一般工程滑坡的共性特征进行分析,综述了各类典型工程滑坡灾害的发育特征、形成机制及部分处置措施。通过不同类型工程滑坡特征的比较分析,总结了工程滑坡成灾的教训和成功处置的经验,为未来工程项目区和城市化过程中工程滑坡的综合防治及风险减缓提供了参考。  相似文献   

20.
滑坡堰塞坝是大型滑坡堆积体堵塞河道形成的土石坝。正、反粒序结构作为大型远程滑坡所特有的2种具有显著差异的地质结构特征,2种情况下坝体的破坏模式差异及稳定性影响因素亟需试验研究。文章通过室内水槽物理模型实验,对比不同粒径、不同结构的滑坡堰塞坝坝体的破坏过程差异,探究了正、反粒序结构条件下堰塞坝的稳定性差异、破坏模式及影响因素。研究结果表明:(1)堰塞坝破坏模式的变化取决于浸润线在下游坡面的出露位置,相比上游水位有一定的延迟性;(2)正、反粒序堰塞坝的破坏模式取决于坡体渗流与下游坡面临界起动坡降的关系;(3)细砂层的位置分布,不同埋深细砂层的起动临界坡降差异和细砂与中粗砂的孔隙率差异是造成正、反粒序坝体破坏差异的主要原因。该研究成果可为大型滑坡堰塞坝的防灾减灾提供理论指导。  相似文献   

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