Probability Of Slope Failure Research Articles

Numerical method of slope failure probability based on Bishop model

Based on Bishop’s model and by applying the first and second order mean deviations method, an approximative solution method for the first and second order partial derivatives of functional function was deduced according to numerical analysis theory. After complicated multi-independent variables implicit functional function was simplified to be a single independent variable implicit function and rule of calculating derivative for composite function was combined with principle of the mean deviations method, an approximative solution format of implicit functional function was established through Taylor expansion series and iterative solution approach of reliability degree index was given synchronously. An engineering example was analyzed by the method. The result shows its absolute error is only 0.78% as compared with accurate solution.

Risk Evaluation of Slope hazard Using Climate Projection Model

Extreme precipitation is forecasted by climate projection model with effect of global warming. The slope hazards are caused by extreme precipitation in the future. It is necessary to evaluate higher dangerous regions by the spatialtemporal distribution for risk mitigation. We made the risk maps of the slope hazard in JAPAN by using climate projection model (MRI-RCM2OVer.2;SRES A2 and MIROC; SERES A 1B) and digital geographic information data. We evaluated slope hazard risks about present, Near-future climate and Future climate. The risk indexes are slope failure probability and economic damage on each land use. As a result, high risk areas are Hokkaido, Toyama pref, Ishikawa pref, Fukui pref and Hyogo pref because over 10billion economic damage extend due to climate change.

Estimation method on slope failure probability at mountain area near source of river

Estimation method on slope failure probability at mountain area near source of river

A new approach for application of rock mass classification on rock slope stability assessment

The objective of this paper is to present a new rock mass classification system which can be appropriate for rock slope stability assessment. In this paper an evaluation model based on combining the Analytic Hierarchy Process (AHP) and the Fuzzy Delphi method (FDM) was presented for assessing slope rock mass quality estimates. This research treats the slope rock mass classification as a group decision problem, and applies the fuzzy logic theory as the criterion to calculate the weighting factors. In addition, several rock slopes of the Southern Cross-Island Highway in Taiwan were selected as the case study examples. After determining the slope rock mass quality estimates for each cases, the Linear Discriminant Analysis (LDA) model was used to classify those that are stable or not, and the discriminant functions which can determine failure probability of rock slopes were carried out by the LDA procedure. Afterward, the results may be compared with slope unstable hazards occurring actually, and then the relation and difference between them were discussed. Results show that the proposed method can be used to assess the stability of rock slopes according to the rock mass classification procedure and the failure probability in the early stage.

Landslide risk assessment and management by decision analytical procedure for Dereköy, Konya, Turkey

The Derekoy landslide threatening the town of Derekoy, Konya, Turkey is investigated in order to assess and manage the associated risk. Derekoy 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 Derekoy 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 Derekoy 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.

A new approach for persistence in probabilistic rock slope stability analysis

Discontinuity persistence is defined as the fraction of area (or length) that is actually discontinuous, with reference to a discontinuity plane which is through the rock mass containing a combination of discontinuities and intact rock regions. Although persistence is one of the most significant discontinuity parameters in slope stability analysis, it is impossible in practice to measure the discontinuity area accurately in a field investigation. Therefore, several researches have carried out on the basis of different approaches such as numerical analysis and fracture mechanics. In this study, the persistence is considered as a random variable since the persistence is difficult to obtain in the field and subsequently involves uncertainty. In addition, while most previous stability analyses have assumed that discontinuity on the failure plane is fully persistent, the probability that the joint length is long enough to produce a rock block failure (or that the joint length is equal to or greater than maximum sliding dimension) is evaluated in this study. That is, the probability of failure obtained from the previous approach is a conditional probability on the premise that the discontinuity on the failure plane is fully persistent. This approach simply uses joint length data rather than the persistence value in the procedure of obtaining the probability of fully persistent joint. Later the probability that fully persistent joint exists is multiplied by the probability of slope failure which itself is based on the assumption that joints are fully persistent. Consequently, in order to overcome the limitation of a conservative analysis, assuming 100% joint persistence, the proposed approach suggested new persistence concept based on the discontinuity length information. In this study, the proposed concept applies to the practical example.

Realistic assessment of slope reliability for effective landslide hazard management

Probabilistic methods have been employed as a practical aid for slope management in respect of the stochastic nature of landsliding. The effect of deterioration on the reliability of slopes of various periods of service, however, has seldom been considered explicitly in the current reliability evaluation. The first part of this paper will present an empirical procedure, using past performance of an extensive set of cut slopes in Hong Kong as an example, to model probabilistically the deteriorating effect on the failure probability with age for a population of slopes. The procedure extends further to predict the failure probability of slopes over different future service periods. Although this probability would serve as an estimate of average slope reliability to assist landslide hazard management by planners, a more accurate site-specific failure probability would be preferred for individual projects. The second part of this paper will adopt a Bayesian procedure to map the calculated probability of a given slope to a more realistic estimate of failure probability. The procedure enables performance records, the effect of system deterioration and other unaccountedfor factors to be systematically incorporated for the estimation. Finally, a procedure is developed to assess the uncertainty associated with the updated probability, resulting from limited observed performance data available for the probability mapping process.

Realistic assessment of slope reliability for effective landslide hazard mangement

Probabilistic methods have been employed as a practical aid for slope management in respect of the stochastic nature of landsliding. The effect of deterioration on the reliability of slopes of various periods of service, however, has seldom been considered explicitly in the current reliability evaluation. The first part of this paper will present an empirical procedure, using past performance of an extensive set of cut slopes in Hong Kong as an example, to model probabilistically the deteriorating effect on the failure probability with age for a population of slopes. The procedure extends further to predict the failure probability of slopes over different future service periods. Although this probability would serve as an estimate of average slope reliability to assist landslide hazard management by planners, a more accurate site-specific failure probability would be preferred for individual projects. The second part of this paper will adopt a Bayesian procedure to map the calculated probability of a given slope to a more realistic estimate of failure probability. The procedure enables performance records, the effect of system deterioration and other unaccountedfor factors to be systematically incorporated for the estimation. Finally, a procedure is developed to assess the uncertainty associated with the updated probability, resulting from limited observed performance data available for the probability mapping process.

Stability and reliability of pit slopes in surface mining combined with underground mining in Tonglushan mine

Slope stability is of critical importance in the process of surface-underground mining combination. The influence of underground mining on pit slope stability was mainly discussed, and the self-stabilization of underground stopes was also studied. The random finite element method was used to analyze the probability of the rock mass stability degree of both pit slopes and underground stopes. Meanwhile, 3D elasto-plastic finite element method was used to research into the stress, strain and rock mass failure resulting from mining. The results of numerical simulation indicate that the mining of the underground test stope has certain influence on the stability of the pit slope, but the influence is not great. The safety factor of pit slope is decreased by 0.06, and the failure probability of the pit slope is increased by 1.84%. In addition, the strata yielding zone exists around the underground test stope. The results basically conform to the information coming from the field monitoring.

A risk-based approach for the design of rock slopes subject to multiple failure modes—illustrated by a case study in Hong Kong

The widening of the Tuen Mun Road highway in Hong Kong involved construction and subsequent operation in an area of steep rock slopes above a heavily trafficked six lane highway. A risk-based approach to slope design was required by the authorities. The approach that was developed is described in detail and includes consideration of risk acceptance criteria, consequence analysis, effects of traffic characteristics, likelihood of slope failure and overall risk and risk allocation. Based on statistical data for slope failures in Hong Kong, world-wide data on dam failures and some engineering judgement, a relation was estimated between annual probability of slope failure and design factor of safety. The implementation of the design involved allocation of acceptable levels of risk to different sections of slope and different modes of slope failure such that the summation of all risk was less than an expected fatality rate of 0.01 deaths per year per 500 m section of slope. This level of risk was determined in relation to objective standards for industrial facilities generally as defined by Hong Kong Planning Guidance criteria (Hong Kong Planning Standards and Guidelines, Hong Kong Planning Department, 1996 (Chapter 11)). These risks were converted into design factors of safety using the likely numbers of failures per mode and per section (more possible failures means that each possible failure location requires a higher factor of safety to achieve the overall risk objectives). Required design factors of safety from this approach were typically in the range 1.2–1.8 compared with a normal requirement in Hong Kong of 1.4.

Time probabilistic evaluation of seismically induced landslide hazard in Irpinia (Southern Italy)

A recently proposed method, which incorporates the Newmark model to evaluate the earthquake-induced landslide hazard at regional scale, was applied to Irpinia, one of the most seismically active regions of Italy. The method adopts a probabilistic approach to calculate values of critical acceleration a c representing the minimum strength required for a slope not to fail at a fixed probability level in a given time interval. Regional probabilistic hazard maps were generated for the two failure types most common in Irpinia (slump–earthflows and rock falls). The results suggest that quite moderate critical acceleration (0.05–0.08 g) could suffice to keep the slope failure probability low. However, the available data indicate that potential slide surfaces with a c below these values could be common in Irpinia, where, perhaps in relation to particular geo-environmental conditions, a relative large number of marginally stable slopes might survive other destabilising actions and fail even on occasion of not particularly strong earthquake shaking.

地震動下での原子力施設周辺斜面の損傷確率評価_-_動的FEMの場合_-_

地震動下での原子力施設周辺斜面の損傷確率評価_-_動的FEMの場合_-_

地震動下での原子炉施設周辺斜面の損傷確率評価_-_すべり面法の場合_-_

地震動下での原子炉施設周辺斜面の損傷確率評価_-_すべり面法の場合_-_

Modeling uncertainty in stability analysis for design of embankment dams on difficult foundations

A probabilistic 3-D slope stability analysis model (PTDSSAM) is developed to evaluate the stability of embankment dams and their foundations under conditions of staged construction taking into consideration uncertainty, spatial variabilities and correlations of shear strength parameters, as well as the uncertainties in pore water pressure. The model has the following capabilities: (1) conducting undrained shear strength analysis (USA) and effective stress analysis (ESA) slope stability analysis of staged construction, (2) incorporation of field monitored data of pore water pressure, and (3) incorporation of increase of undrained shear strength with depth, effective stress, and pore water pressure dissipation. The PTDSSAM model is incorporated in a computer program that can analyze slopes located in multilayered deposits, considering the total slope width. The main outputs of the program are the geometric parameters of the most critical sliding surface (i.e., center of rotation/radius of rotation and critical width of failure), mean 2-D safety factor, mean 3-D safety factor, squared coefficient of variation of resisting moment, and the probability of slope failure. The program is applied to a case study, Karameh dam in Jordan. Monitored data of induced pore water pressure in the dam embankment and soft foundation were gathered during dam construction. The stability of Karameh dam embankment and foundation was evaluated during staged construction using deterministic and probabilistic analysis. Foundation stability was evaluated based on the monitored data of pore water pressure. The study showed that the mean values of the corrective factors which account for the discrepancies between the in situ and laboratory-measured values of soil properties and for the modeling errors have significant influence on the 2-D safety factor, 3-D safety factor, slope probability of failure, and on the expected failure width. The degree of spatial correlation associated with shear strength parameters within a soil deposit also influences the probability of slope failure and the expected failure width. This correlation is quantified by scale of fluctuation. It is found that a larger scale of fluctuation gives an increase in the probability of slope failure and a reduction in the critical failure width.

Spatial probabilistic modeling of slope failure using an integrated GIS Monte Carlo simulation approach

Spatial probabilistic modeling of slope failure using a combined Geographic Information System (GIS), infinite-slope stability model and Monte Carlo simulation approach is proposed and applied in the landslide-prone area of Sasebo city, southern Japan. A digital elevation model (DEM) for the study area has been created at a scale of 1/2500. Calculated results of slope angle and slope aspect derived from the DEM are discussed. Through the spatial interpolation of the identified stream network, the thickness distribution of the colluvium above Tertiary strata is determined with precision. Finally, by integrating an infinite-slope stability model and Monte Carlo simulation with GIS, and applying spatial processing, a slope failure probability distribution map is obtained for the case of both low and high water levels.

Stability of Cut Slopes Against Shallow Failure: Evaluation by Neural Network Model

The discrimination model for road cut slope stability was used to assess 216 cut slope locations on the Chuo Expressway. This model ranks the failure probability of slopes by the rainfall threshold (cumulative precipitation that causes the slope to fail) to identify slopes highly prone to collapse. Because of the complexity (nonlinearity) of the relationship between the factors relating to the cut slope failure and the precipitation that triggers a failure, it has been difficult to correctly evaluate the likelihood of failure for cut slopes. The developed model has overcome that difficulty by involving the neural network as the discrimination technique. The input data included the different factors (topography, soil properties and geology, surface layer status, change in state) in the stability investigation table prepared at the time of road slope inspection, with additional information such as catchment topography. The cut slope data were prepared, referring to a variety of information encompassing the failure history for 30 years after the commencement of service, the rainfall record at the time of failure, the maximum rainfall amount ever recorded, and the data on the status of slope protection around the time of failure. As shown by the discrimination results, the model accuracy (ratio of correct answers to number of slopes evaluated) was as high as approximately 80%, which allowed accurate determination of the amounts of rainfall inducing the failure of different slopes.

Seismic reliability analysis of earth slopes under short term stability conditions

Different models were developed for evaluating the probabilistic three-dimensional (3-D) stability analysis of earth slopes and embankments under earthquake loading. The 3-D slope stability model assumed is that of a simple cylindrical failure surface. The probabilistic models evaluate the probability of failure under seismic loading considering the randomness of earthquake occurrence, and earthquake induced acceleration and uncertainties stemming from the discrepancies between laboratory-measured and in-situ values of shear strength parameters. The models also takes into consideration the spatial variabilities and correlations of soil properties. The probabilistic analysis and design approach is capable of obtaining the 2-D and 3-D static and dynamic safety factors, the probability of slope failure, the earthquake induced acceleration coefficient, the yield acceleration coefficient, the earthquake induced displacement, and the probability of allowable displacement exceedance taking into account the local site effect. The approach is applied to a well known landslide case: Congress Street Landslide in Chicago. A sensitivity analysis was conducted on the different parameters involved in the models by applying those models to the Congress Street landslide considering different levels of seismic hazard. Also, a sensitivity analysis was carried out to study the sensitivity of computed results to input parameters of undrained shear strength, and corrective factors. A comparison was made between the different models of failure. The parametric study revealed that the hypocentral distance and earthquake magnitude have major influence on the earthquake induced displacement, probability of failure and dynamic 2-D and 3-D safety factors.

Evaluating Slope Stability in Forest Uplands with Deterministic and Probabilistic Models

Research Article| January 01, 1998 Evaluating Slope Stability in Forest Uplands with Deterministic and Probabilistic Models THOMAS E. KOLER THOMAS E. KOLER Intermountain Natural Resource Consultants, 5258 Matson Road, Viola, ID 83872 Search for other works by this author on: GSW Google Scholar Environmental & Engineering Geoscience (1998) IV (2): 185–194. https://doi.org/10.2113/gseegeosci.IV.2.185 Article history first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation THOMAS E. KOLER; Evaluating Slope Stability in Forest Uplands with Deterministic and Probabilistic Models. Environmental & Engineering Geoscience 1998;; IV (2): 185–194. doi: https://doi.org/10.2113/gseegeosci.IV.2.185 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyEnvironmental & Engineering Geoscience Search Advanced Search Abstract Deterministic Level I Stability Analysis (DLISA) and probabilistic Level I Stability Analysis (LISA) models provide information for a slope stability analysis. These computer codes have been developed, tested, and validated by U. S. Department of Agriculture Forest Service researchers. The purpose of this research was to provide engineers and scientists a personal computer program for evaluating potential slope instability within planning areas in forested uplands. Physical soil values within the infinite slope equation are evaluated within DLISA for possible frequency distributions. LISA, the probabilistic computer program, adds a stochastic simulation by the Monte Carlo method of these frequency distributions. The result from these analyses is a probability of slope failure. Potential shallow landslides, such as debris flows, have been evaluated since 1987 and can be predicted with DLISA and LISA. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Probabilistic analysis of rock slope stability with first-order approximation

Based on the theory of probability, the probabilistic analysis of slope stability is conducted. Equations for the estimation of slope failure probability are first derived using direct integrations. However, the complexity of the integrations is formidable. In order to overcome the limitation of the direct integration, the first-order second-moment approximation of the slope failure probability is employed for more complex slope stability problems. The study indicates that the distributions of parameter values play a significant role in slope stability, which can not be disclosed by the conventional methods of stability analysis. Greater dispersiveness of the parameter values will lead to a different probability of failure, although the factor of safety estimated by conventional methods remains the same if the mean values of the parameters are unchanged. By taking consideration of the distributions of the parameters, the probability model can provide more reliable designs of rock slopes.

A random-field approach to slope failure along a sub-sea pipeline route

Under certain conditions, the occurrence of slope failures in a fjord can be described as a Poisson process in time and space. This is used in conjunction with random-field theory to derive expressions for the probability of slope failure on the seabed of the fjord in a specified reference period, and for the probability that a pipeline through the fjord is struck by such a slope failure during this period. Solution of the probabilities by these expressions capitalizes on observed data for rate of slide occurrences and size of slide areas. Whereas the probability of slope failure in a fjord gives a general indication of the likelihood of having a slope failure in the fjord, the probability that a pipeline through the fjord is struck by such a slope failure is an important measure in checks against code requirements, should a strike by sliding soil masses imply an adverse condition for the pipeline. For demonstration of this random-field approach to assessment of the slope failure hazard along a pipeline route in a fjord, a numerical example is given in which the derived probability expressions are applied to a sample pipeline for conditions prevailing in a fjord on the west coast of Norway.