Risk Analysis Of Slopes Research Articles

Enhancing resilience by considering climate change influenced bushfire in slope risk analysis

Enhancing resilience by considering climate change influenced bushfire in slope risk analysis

Stability analysis of slopes based on cloud model-Monte Carlo coupling

Risk analysis of dam slopes is crucial for ensuring the safety and stability of hydraulic engineering. To improve the accuracy and reliability of risk analysis, we adopt the cloud theory approach and conduct a study on the distribution types of soil shear strength indicators based on indoor geotechnical tests. We propose a “cloud model-Monte Carlo” coupling model that uses the cloud model to describe the uncertainty of risk factors and determine the probability distribution types of shear strength parameters, while the Monte Carlo method is used to simulate random variables in the model. The effectiveness of the proposed model is validated through a risk analysis of a slope of an earth-rock dam, with results showing significantly greater accuracy and reliability compared to traditional methods. The calculation results show that the risk probability corresponding to the design flood level of the dam is 9.01×10-6, exceeding its allowable risk standard of 0.5×10-6, hence the need for reinforcement treatment. The proposed model can accurately evaluate the risk of dams and provide the scientific basis for decision-making in dam safety management.

Anchored Slope Risk Analysis under Earthquake Effect

Horizontal earthquake acceleration is used for slope risk analysis, and the relationship between the dynamical safety factors and corresponding static safety factors is obtained. The reliability of anchored slope is expressed with the safety factor. The synthesized risk evaluation index, which included the dynamical, statically mechanics and reliability analysis, is established. The main procedure of calculation is provided by a practical project in this paper, and the computed example has shown it is worthy to study the method further.

The Slope Risk Analysis of Tailings Dam under the Coupling Effect of Rainstorms and Earthquakes

For slope risk analysis of tailings dam, the current research focuses on treating physical and mechanical parameters of tailing materials as the basic random variables. The influence of the external natural random factors is considered little. In practice, the slope stability of tailings dam is influenced by not only their random material parameters but the various natural factors including the changes of water level and the seismic intensity size. As a rule of thumb, there might be heavy rains before the earthquake. Therefore, it is necessary to comprehensively consider the slope risk of tailings dam under the coupling effect of rainstorms and earthquakes. Aiming at this problem, reliability theory was employed in this paper to study the influence under both rainstorms and earthquake actions. In this project, the slope risk analysis of tailings dams is evaluated under natural multi-random factors.

The application of quantitative risk assessment in talus slope risk analysis

Talus slopes have poor stability on both sides of freeways, which usually leads to landslides and results in great damage, so the process of construction and operation is full of risks. Quantitative risk assessment (QRA) is a method of quantifying the degree of risk through a systematic examination of the factors contributing to slope stability and affecting the severity of the consequences. It has become an important tool for the management of landslide risk and for planning risk mitigation measures. In this paper, a QRA method is described in detail and the risk of a talus landslide in Shuima freeway of Yunnan Province is analysed using this method. Some risk mitigation measures are also suggested. Through the application, the merits and limitations of the method of QRA are also discussed.

STUDY ON SEISMIC RISK ANALYSIS OF SLOPES AND EARTH STRUCTURES

The purpose of the present paper is to propose a methodology of the seismic risk analysis of slopes and earth structures based on the seismic coefficient. First, attenuation study of peak acceleration for various earthquakes in Japan is made and this shows noticeable scatterness depending upon the region of the earthquake. Second, the records of about twenty thousands earthquakes which occured in Japan are investigated to determine the area of “earthquake nest” and Gutenberg-Richter's equation is given for each “earthquake nest.” These results are incorporated with the seismic risk analysis assuming the circular seismic source and poisson process as a seismic source model. The actual cases are analysed by the proposed method and they show the validity of the method to distinguish the failure case and non-failure case.

A Method for Risk Analysis of Slopes and Its Application to Slopes in Sakurajima Volcano

The most important problem in the risk analysis of slope is how to predict an unstable slope. In this paper, a method of evaluation for the risk degree of slope failures is described by the application of Hayashi's quantification method III, which is a mathematical-statistical method in order to convert qualitative data into quantitative relations. The investigated area is Sakurajima volcano located in the center of Kagoshima Bay, southern Kyushu, Japan. Taking engineering aspects into consideration, the basic data relevant to slope stability were obtained on topographic and geotechnical conditions, land utilization and vegetation in a fixed unit area overlaied with the mesh of 250m square.8 items and 33 categories are chosen as the factors of characterizing the unit area. The collected data are categorical, that is, non-numerical and qualitative, data, which can be quantified by the use of a suitable computer program based on the theory of quantification. Numerical values given to each category for the quantification are elements of eigenvectors, which are obtained from vector equation, corresponding to eigenvalues which are obtained from characteristic matrix. According to the relative distance between a couple of categories which can be calculated by elements of eigenvectors, each category is grouped into five classes, which are given the score of risk degree estimated by the values from 0 to 4. The rank of risk level is determined from the total scores of risk degree and finally a classification map of risk level of slope is presented.The remarkable feature of this paper is that the score of risk degree for categorical data of slopes was determined theoretically by the grouping classification using a mathematical-statistical approach. Moreover, it is greatly interested to note that the informations of slope failures are not always required in applying the method III to the prediction of risk degree of slope.

Discussion: Risk analysis of slopes and its application to slopes in Canadian sensitive clays

Discussion: Risk analysis of slopes and its application to slopes in Canadian sensitive clays

Risk analysis of slopes and its application to slopes in Canadian sensitive clays : Alonso, EE Geotechnique, V26, N3, Sept 1976, P453–472

An interesting risk analysis of clay slopes for short-term and long-term analysis, including pore water pressures in sensitive clays, is presented. Application of the analysis to typical clay slopes indicates the contribution of different soil parameters and model uncertainty to the total variance and probability of stability failure. Current design factors give a relatively high risk of failures in practice and are justified on economic grounds except for embankment dams. /Author/

Risk analysis of slopes and its application to slopes in Canadian sensitive clays

The problem of defining better measures of the safety of slopes has been approached from a probabilistic point of view. Using a mechanistic description of stability (the method of slices), a first order probability analysis was implemented in order to allow for a rational evaluation of the different sources of uncertainty involved. A preliminary sensitivity analysis shows that the uncertainties in the cohesion parameter, the pore-pressure and the method of analysis are the relevant ones in governing the resulting uncertainty in the slope safety. The method developed serves, however, to predict the probability of failure of a given slope once the different types of uncertainty can be quantified. The analysis of an actual case of slope failure in sensitive clay deposits leads to a number of graphs showing the variation of risk with (a) level of uncertainty in the involved parameters, and (b) the degree of correlation of soil properties. A relationship between mean safety factor and probability of failure is then developed for the conditions likely to prevail in Champlain Sea deposits. This relationship compares well with previous published results based only on empirical observations. Le problème de la détermination de meilleures mesures pour la sécurité des pentes a été approché au point de vue probabilité. En utilisant une description mécanique de stabilité (la méthode des tranches), une première règle d'analyse de probabilité fut exécutée afin de permettre une évaluation rationnelle des différentes sources d'erreurs en cause. Une analyse préliminaire de sensibilité montre que les erreurs relatives au paramètre de cohésion, à la pression interstitielle et à la méthode d'analyse, sont les plus importantes en ce qui concerne les erreurs finales dans la securité des pentes. La méthode développée sert néanmoins, à prédire la probabilité de rupture d'une pente donnée, une fois que les différents types d'erreurs peuvent être quantifiés. L'analyse d'un cas réel d'une rupture de pente dans des dépôts d'argile sensible au remaniement, conduit à un nombre de graphiques montrant la variation du risque avec: (a) les erreurs dans les paramètres en jeu, et (b) le degré de corrélation des propriétés du sol. Une relation entre un facteur de sécurité moyen et une probabilité de rupture est alors établie pour les conditions probablement dominantes dans les dépôts de mer de Champlain. Cette relation correspond bien aux résultats publiés antérieurement et basés seulement sur des observations empiriques.