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1.
我国多山,崩塌灾害频繁发生,相应的风险评价也得到了越来越多的关注。由于崩塌发生和运移过程的高度不确定性以及历史数据的不完备,往往很难进行相应的定量风险评价。四川罗家青杠岭的崩塌现场非常典型,而且现场资料较全、历史数据较多并且明确,是开展崩塌风险定量研究的很好实例。通过现场工程地质调查、测绘和统计分析,确定了历史崩塌的物源区、堆积区、最大运移距离、年发生概率以及坡体上的4块典型危岩体A-D。基于历史崩塌堆积区的块石统计特征以及物源区危岩体失稳启动位置的不确定性,利用二维Rockfall模拟软件对所在坡面的恢复系数及摩擦系数进行了反演。在此基础上,对危岩体A-D失稳后的运动特征进行了随机性数值模拟和统计分析,从而确定了崩塌的到达概率。基于崩塌发生概率、到达概率、承灾体时空分布概率和易损性的乘积,作者对罗家青杠岭崩塌进行了定量风险评价。评价结果表明,危岩体A和D的风险值处于不可接受的风险区间,块石B和C的风险值处于警告的风险区间,严重威胁着坡脚附近居民的生命财产安全,有必要采取相应的防灾减灾措施。 相似文献
2.
单体危岩崩塌灾害风险评价方法——以四川省丹巴县危岩崩塌体为例 总被引：4，自引：0，他引：4
综合分析国内外危岩崩塌风险评价方法的基础上,以丹巴县双拥路危岩崩塌体为例,提出了适用于单体危岩崩塌的风险评价方法。根据蒙特卡洛法的基本原理及方法编制了危岩崩塌体的稳定性可靠度分析程序,计算了不同工况下危岩失稳的概率。同时,考虑地面建筑物对落石的阻挡影响,利用专业软件模拟落石的运动轨迹,并根据研究区的地形地貌特点进一步确定了落石的影响范围。在野外调查和收集当地社会经济资料的基础上,开展了承灾体的易损性研究,对资产的易损性进行了评价。根据危岩失稳的概率及承灾体的易损性分析,进一步得到不同工况下落石影响区内承灾体的经济损失水平,对危岩崩塌灾害的风险进行了定量评价。风险评价的结果可为危岩崩塌灾害影响区的城镇建设和规划提供科学依据,从而有效地规避风险和减灾防灾。 相似文献
3.
Jordi Corominas Ramon Copons José Moya Joan M. Vilaplana Joan Altimir Jordi Amigó 《Landslides》2005,2(4):343-357
Quantitative Risk Assessment (QRA) has become an indispensable tool for the management of landslide hazard and for planning
risk mitigation measures. In this paper we present the evaluation of the rockfall risk at the Solà d’Andorra slope (Andorra
Principality) before and after the implementation of risk mitigation works, in particular, the construction of protective
fences. To calculate the risk level we have (i) identified the potential rockfall release areas, (ii) obtained the volume
distribution of the falling rocks, (iii) determined the frequency of the rockfall events, and (iv) performed trajectographic
analysis with a 3D numerical model (Eurobloc) that has provided both the expected travel distances and the kinetic energy
of the blocks. The risk level at the developed area located at the foot of the rock cliff has been calculated taking into
account the nature of the exposed elements and their vulnerability. In the Forat Negre basin, the most dangerous basin of
the Solà d’Andorra, the construction of two lines of rockfall protection fences has reduced the annual probability of loss
of life for the most exposed person inside the buildings, from 3.8×10−4 to 9.1×10−7 and the societal risk from 1.5×10−2 of annual probability of loss of life to 1.2×10−5. 相似文献
4.
ROckfall risk MAnagement assessment: the RO.MA. approach 总被引：1，自引：1，他引：0
The analysis of risk for vehicles and drivers as a result of rockfall on a road is relevant to design management in geotechnical engineering. This process is very complex due to the large number of parameters involved. In this paper, we discuss risk analysis and management procedures for roads subject to rockfall phenomena. To this aims, we are proposing a quantitative method (the RO.MA. approach). We developed an abacus to define the threshold values of acceptable rockfall risk for a given road. Rockfall risk is calculated using an Event Tree approach and compared with the abacus thresholds to evaluate road safety and the need for additional protective measures to reduce the risk to an acceptable level. The approach was successfully applied at a test site located in Bard, Aosta Valley, north-western Italy. 相似文献
5.
Rockfall risk assessment to persons travelling in vehicles along a road: the case study of the Amalfi coastal road (southern Italy) 总被引：2，自引：0，他引：2
The paper deals with the assessment of rockfall risk to persons travelling in vehicles along the SS163 road, an important transportation corridor supporting a high vehicle traffic within the well-known tourist area of the Amalfi Coast (southern Italy). To this aim, the Rockfall Hazard Rating System (RHRS) and quantitative risk assessment (QRA) procedures, in this latter case for three rockfall risk scenarios, are applied. With reference to a large portion (33.820 out of a total of 50.365 km) of the SS163 road, the obtained QRA results highlight that, although the estimated individual risk to life satisfies the adopted tolerable risk criterion, the computed societal risk cannot be tolerated. Starting from this result, site-specific QRA analyses—carried out with reference to some road sections chosen on the basis of the RHRS results—allow the detection of the SS163 portions where the individual risk to life exceeds the tolerable risk threshold and, then, the recourse to mitigation measures could reveal necessary. In this regard, RHRS and QRA methods can be considered complementary tools in prioritizing the road sections where construction funds can be profitably spent in order to mitigate the rockfall risk with reference to both direct consequences (life loss) and indirect ones (traffic delay and diversions). 相似文献
6.
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7.
Renato Macciotta C. Derek Martin Norbert R. Morgenstern David M. Cruden 《Landslides》2016,13(4):765-785
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
8.
In dam safety assessment, it is customary to focus on stability analysis, and the safety factor is regarded as an assessment
index that cannot correctly reflect the effect of multi-factors and variable uncertainty. The factors that induce dam breaks
are complex and uncertain; however, three primary ones can be identified: hydrological factors, seepage and bank slope instability.
In this paper, the risk probability and the dam break threshold value for each factor individually, as well as coupled factors,
are studied. The threshold value is acquired using the relationship formula between risk probability and dam type. The Dongwushi
reservoir located in the Hebei province of China is taken as a case study. The results show that the dam break threshold values
for hydrological factors, seepage and bank slope instability are 2.53, 2.02 and 2.69, respectively. The integrated dam break
threshold value for the coupled factors is 1.25, which indicates that the dam is under serious stress according to the established
risk assessment standard. The safety factor is calculated as 1.15 using the Bishop method, which indicates that the dam is
under serious stress. The results obtained by the proposed method are consistent with those of the Bishop method. Finally,
the proposed theory and method are introduced into a dam safety evaluation system (DSES) for convenient and efficient dam
safety management. 相似文献
9.
山西壶关太行山大峡谷景区为中国最美十大峡谷之一,但景区落石灾害频发,严重威胁景区安全运营。本文基于高精度地形信息与岩土体强度特性,采用坡度角分布方法开展区域尺度潜在落石源区识别,并引入岩体破坏敏感性指标定量描述潜在落石源区失稳概率。然后,利用经验模型Flow-R模拟落石运动扩散过程,获取落石的传播概率与能量分布情况。最后,提出落石危险性双因子评价模型实现落石危险性定量评估。获得主要结论如下:(1)研究区内潜在落石源区面积为25.7 km2(35.7%),主要以条带状分布于峡谷两侧陡壁。其中岩体破坏高敏感性区为3.3 km2。(2)研究区落石高危险区面积达3.22 km2,主要威胁景区内游客集散地与交通线路,尤其在S327荫林线红豆峡入口处落石危险性最高。(3)野外调查验证结果表明了应用坡度角分布方法识别潜在落石源区的高效性与准确性,提出的双因子评价模型可为峡谷区落石危险性评估提供快速解决方案。本文提出的“区域落石源区识别-源区失稳概率分析-落石危险性评估”的一整套技术方案能够为类似的高山峡谷区落石灾害早期识别及风险防控提供技术参考。 相似文献
10.
本文以北京市怀柔区为例,通过现场调查,对688处崩塌灾害分别以面数据和点数据的形式获取了两套编目图。根据现场调查和资料分析,选取岩性、地形、断裂和道路建设作为该区崩塌灾害的主控因素,采用频率比(FR)模型对崩塌灾害的易发性进行了评价。为了对评价结果的预测性进行检验,采用随机分割法,选取了415处崩塌用于频率比模型的计算,剩余的273处崩塌用于评价结果预测性的验证。预测曲线表明,基于崩塌面数据的评价结果比基于点数据的评价结果具有明显的优越性。根据基于面数据的频率比模型评价结果,可以将研究区的崩塌灾害易发性划分为5个等级:较低易发(占全区14%)、低易发(占全区20%)、中等易发(占全区27%)、高易发(占全区22%)和极高易发(占全区17%)。相关工作和结论可以为区域地质灾害易发性评价中编目图的编制提供参考,并为怀柔区区域国土利用和防灾减灾提供指导。 相似文献
11.
Rockfalls are common in the steep and vertical slopes of the Campania carbonate massifs and ridges, and frequently represent
the main threat to the anthropogenic environment, potentially damaging urban areas, scattered houses, roads, etc. Despite
the generally limited volumes involved, the high velocity of movement (from few to tens of metres per second) poses rockfalls
among the most dangerous natural hazards to man. Evaluating the rockfall hazard is not an easy task, due to the high number
of involved factors, and particularly to the difficulty in determining the properties of the rock mass. In this paper, we
illustrate the assessment of the rockfall hazard along a small area of the Sorrento Peninsula (Campania region, southern Italy).
Choice of the site was determined by the presence of a road heavily frequented by vehicles. In the area, we have carried out
detailed field surveys and software simulations that allow generating simple rockfall hazard maps. Over twenty measurement
stations for geo-mechanical characterization of the rock mass have been distributed along a 400-m-long slope of Mount Vico
Alvano. Following the internationally established standards for the acquisition of rock mass parameters, the main kinematics
have been recognized, and the discontinuity families leading to the different failures identified. After carrying out field
experiments by artificially releasing a number of unstable blocks on the rock cliff, the rockfall trajectories along the slope
were modelled using 2-D and 3-D programs for rockfall analysis. The results were exploited to evaluate the rockfall hazard
along the threatened element at risk. 相似文献
12.
Rockfall susceptibility zoning at a large scale: From geomorphological inventory to preliminary land use planning 总被引：3，自引：0，他引：3
Rockfall, up to several hundreds of cubic meters, is a frequent and rapid landslide which menaces extensive areas in mountainous territories. Rockfall susceptibility zoning map at a large scale (1:5000–1:25 000) can be the first tool for land use planning in order to manage rockfall risk. A methodology allowing to analyze susceptibility in extensive areas with optimum cost/benefit relationship is needed. This work analyzes rockfall susceptibility in an extensive rocky mountain of the Principality of Andorra (Pyrenees Mountains), first on the rock slope and then on the exposed area located below. The rockfall record, obtained by means of geomorphological analysis, supplies the main data to analyze the susceptibility on the rock slope. An additional historical inventory verifies the accuracy of rockfall sizes recorded by means of the geomorphological analysis. According to the classification recommended by the Guidelines of Joint Technical Committee, the density of rockfall features on the rock slope assesses susceptibility in four levels. Subsequently, susceptibility on exposed areas has been analyzed by means of reach probability of rock blocks analysis using empirical models. Data acquired from thirteen recent events, from 1999 to 2004, have been used to verify the accuracy of the two empirical models mainly used (reach angle and shadow angle). Five reach probability limits (1, 0.5, 0.25, 0.01, and 0) establish boundaries between susceptibility levels. The resulting rockfall susceptibility zoning map allows: (a) to identify land areas and human elements exposed to rockfalls and, (b) to establish several exposition levels. This map can be a useful and cost-effective tool for administrations responsible to manage natural risk in order to guide urban grow in extensive areas or decide upon work programs based on in-depth analysis (hazard and risk). 相似文献
13.
提出了基于子集模拟的边坡风险评估的高效随机有限元法（RFEM）,推导了基于子集模拟的边坡失效概率和失效风险的计算公式,并给出了基于高效RFEM的边坡可靠度分析和风险评估流程图。采用一个边坡算例验证了所提方法的有效性。结果表明,基于子集模拟的高效RFEM可以视为是对基于蒙特卡洛模拟的传统RFEM的改进,显著地提高了失效概率和失效风险的计算效率以及失效样本的产生能力,非常适用于分析小失效概率的可靠度问题,极大地增强了RFEM在边坡可靠度分析和风险评估中的实用性。高效RFEM将边坡的整体失效风险分解为对应不同概率水平的边坡失效风险,并量化了它们对整体风险的相对贡献度。在该方法中,边坡可靠度分析和风险评估与确定性边坡有限元分析互不耦合,极大地简化了它们的计算过程。此外,土体不排水抗剪强度的竖向空间变异性对边坡失效风险具有显著的影响。 相似文献
14.
不良地质条件是影响TBM施工隧洞管片结构安全的重要因素。综合考虑围岩地质条件和衬砌结构的不确定性,提出了一种定量分析TBM管片结构失事概率的新方法。在基于Markov过程估计隧洞沿程地质岩性变化概率的基础上,建立了隧洞任意位置处管片选型不匹配的概率模型;考虑围岩和管片参数的不确定性,采用随机有限元方法计算某一类型管片在不同围岩下的失事概率;由此,采用全概率公式,可计算隧洞沿程任意位置处管片结构的失事概率。结合实际工程,针对施工期工况,确定了该隧洞管片沿程的失事概率、最大失事概率及其所对应的位置等,为管片选型、优化设计及TBM施工期的风险防范提供了依据。 相似文献
15.
A. Deif I. El-Hussain K. Al-Jabri N. Toksoz S. El-Hady S. Al-Hashmi K. Al-Toubi Y. Al-Shijbi M. Al-Saifi 《Arabian Journal of Geosciences》2013,6(12):4947-4960
The Sultanate of Oman forms the southeastern part of the Arabian plate, which is surrounded by relatively high active tectonic zones. Studies of seismic risk assessment in Oman have been an important on-going socioeconomic concern. Using the results of the seismic hazard assessment to improve building design and construction is an effective way to reduce the seismic risk. In the current study, seismic hazard assessment for the Sultanate of Oman is performed through the deterministic approach with particular attention on the uncertainty analysis applying a recently developed method. The input data set contains a defined seismotectonic model consisting of 26 seismic zones, maximum magnitudes, and 6 alternative ground motion prediction equations that were used in four different tectonic environments: obduction zone earthquake (Zagros fold thrust belt), subduction zone earthquakes (Makran subduction zones), normal and strike-slip transform earthquakes (Owen and Gulf of Aden zones), and stable craton seismicity (Arabian stable craton). This input data set yielded a total of 76 scenarios at each point of interest. A 10 % probability that any of the 76 scenarios may exceed the largest median ground acceleration is selected. The deterministic seismic hazards in terms of PGA, 5 % damped spectral acceleration at 0.1, 0.2, 1.0 and 2.0 s are performed at 254 selected points. The ground motion was calculated at the 50th and 84th percentile levels for selected probability of exceeding the median value. The largest ground motion in the Sultanate of Oman is observed in the northeastern part of the country. 相似文献
16.
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
17.
隧道仰坡落石冲击模型试验研究与机制探讨 总被引：1，自引：0，他引：1
以在建的成都－兰州（成兰）铁路某隧道出口仰坡为研究对象,研发了大型落石冲击边坡模型试验系统,该系统由模型试验台架、落石三维空间释放装置、高速摄影系统等组成,结构强度高并能满足试验过程的可视化需求。根据现场岩样实测物理力学参数,采用凡士林、硅油、水泥、细沙、重晶石粉、石膏以及滑石粉等原料,研制出现场千枚岩和砂岩的相似材料,并用于模拟边坡和落石。通过开展物理模型试验研究了近长方体落石初始滑移角度、形状、质量等3种因素对碰撞恢复系数这一落石运动轨迹模拟中关键参数的影响,同时在落石下落冲击的过程中,利用高速摄影仪和坐标卡尺记录落石完整的运动轨迹,后期通过视频处理软件分析落石与边坡碰撞前后的速度变化,根据公式计算出落石法向和切向的碰撞恢复系数。试验结果表明：随着初始滑移角度的增加,板状试件的法向、切向恢复系数分别呈减小和增大的趋势,且切向恢复系数变化更加明显;落石法向恢复系数随质量的增加呈明显减小的趋势,而切向恢复系数值变化不大;对于近长方体落石,立方体试件的法向和切向恢复系数大于厚板状试件,条形试件的两向恢复系数值受碰撞接触形态的影响,呈现两极化的趋势。最后,结合试验现象以及前人的研究成果对落石运动冲击机制进行了初步探讨。 相似文献
18.
地下水污染风险研究在工程决策中具有重要意义。但地下水系统本身具有各种不确定性,基于这些不确定性的地下水污染风险评价也因此具有不确定性,而且贯穿整个地下水污染风险评价过程。所以,进行不确定性分析是对地下水污染风险进行评价时的必要步骤。一般来讲,基于不确定性分析的地下水污染风险评价结果更可靠,因此也更具有实用价值。本文在对不确定性进行分类（随机不确定性和模糊不确定性）的基础上,通过大量文献调研和分析,对目前国内外用于地下水污染风险评价分析的不确定性分析方法（包括随机理论方法、模糊理论方法、随机-模糊耦合方法等）进行了归纳总结,并基于各种方法目前的研究现状,分析了不确定性理论在地下水污染风险评价研究中的发展前景。 相似文献
19.
G. Grünthal A. H. Thieken J. Schwarz K. S. Radtke A. Smolka B. Merz 《Natural Hazards》2006,38(1-2):21-44
In this paper a methodology for a multi-risk assessment of an urban area is introduced and performed for the city of Cologne,
Germany, considering the natural hazards windstorm, flooding and earthquake. Moreover, sources of the uncertainty in the analysis
and future needs for research are identified. For each peril the following analyses were undertaken: hazard assessment, vulnerability
assessment and estimation of losses. To compare the three hazard types on a consistent basis, a common economic assessment
of exposed assets was developed. This was used to calculate direct economic losses to buildings and their contents. The perils
were compared by risk curves showing the exceedence probability of the estimated losses. In Cologne, most of the losses that
occur frequently are due to floods and windstorms. For lower return periods (10–200 years) the risk is dominated by floods.
For return periods of more than 200 years the highest damage is caused by earthquakes. 相似文献
20.
Xueliang Wang Luqing Zhang Jixin Ding Qingfeng Meng Javed Iqbal Lihui Li Zhifa Yang 《Environmental Earth Sciences》2014,72(11):4639-4652
This study shows a rockfall susceptibility assessment at local scale in north Beijing of China, including the identification of rockfall sources onsite by terrain and rock discontinuities analysis and run-out distance prediction by Rocfall? simulation. Two types of rockfall were defined including one type on the cliffs with long inclined slopes and another type on the road slopes with low height. Two historical rockfall events were used to back-calibrating the parameters used for run-out distance simulation. Based on the work, rockfall susceptibility map at local scale was created in GIS, which was compared with the map obtained at regional scale (entire Huairou district scale). Due to the difference of approaches applied, procedure of assessment and types of source data acquired, the two resulting rockfall susceptibility maps are proved to be different. Still, both of them are useful and could be used at different level’s decision for rockfall prevention and mitigation. Different types of uncertainties exist in the study of rockfall susceptibility assessment. To reduce the uncertainties, studies on both approaches and techniques are suggested. 相似文献