Soil uncertainties play an important part in the analysis and design of geotechnical structures. The effect of uncertainties on the geotechnical structures and their influence on the probability of failure or reliability of the structure is of great interest for geotechnical researchers. Probabilistic-based slope stability analysis incorporates the uncertainties present in the soil, as expressed in terms of mean, variance, and autocorrelation. In this paper, reliability analysis of a finite cohesive soil slope based on the probabilistic approach is presented using the First Order Second Moment (FOSM) method, First Order Reliability Method (FORM), and Monte Carlo Simulation (MCS) method. Stability analysis has been performed using the ordinary method of slices to calculate the Factor Of Safety (FOS) of the slope under undrained conditions. The reliability analysis has been implemented in the MS-excel spreadsheet environment and was mainly focused on the two models, namely the deterministic model for calculating the FOS of the slope and the uncertainty model for generating the random variables of uncertain soil parameters. The reliability index (β) of the soil slope and its corresponding probability of failure (Pf) was calculated using the above methods. The obtained result shows that the MCS method has significantly shown better performance than FOSM and FORM because of its robustness and simple approach to calculate Pf and β of the slope.

In geotechnical engineering, uncertainties arise due to variation in loads, soil characteristics, ground stratification and so on. Reliability analysis based on probabilistic approaches is particularly suitable to deal with such uncertainties. In this paper, a newly developed reliability analysis method, namely Subset simulation (SS) method has been implemented to study the stability of a cohesive slope. The results of reliability analysis obtained from SS method are also compared with three other methods, namely First order second moment method (FOSM), First order reliability method (FORM) and Direct Monte-Carlo simulation (MCS) method. The various reliability models have been used in a spreadsheet environment using MS-Excel. The developed spreadsheet-based platform implementing all four methods contains two common models i.e. deterministic model and the uncertainty model. The SS method uses another model called uncertainty propagation using subset simulation (UPSS) in addition to the two above-mentioned models. The factor of safety  of the slope is determined using ordinary method of slices under undrained condition. The probability of failure (  and its corresponding reliability index  of the proposed slope has been determined using all four methods. A software called Geo-Studio (SLOPE/W) has been used to tally the results of reliability analysis of the slope considered herein. The results obtained from the different methods show that the SS method gives better performance in terms of efficiency and resolution especially at low failure probability i.e., . Also, the SS method helps in identifying the significant depth where the most probable critical slip surface is located.

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In geotechnical engineering uncertainties arises from loads, soil characteristics and their properties, calculation models etc. To minimize these uncertainties in geotechnical problem, various reliability based and (or probabilistic based) approaches have been developed. This abstract presents a MS-Excel spreadsheet environment based practical framework for estimating the reliability index and failure probability of a cohesive finite slope using First-order second moment method, First-order reliability method and Monte Carlo Simulation. The height and the angle of slope is considered to be 5 m and 45º respectively. The inclination of the slope is 2H:1V and the hard stratum is assumed to be present at 15 m below the soil. The values of saturated unit weight and undrained shear strength are assumed to be 18 kN/m3 and 20 kPa respectively. The stability analysis is carried out using Swedish slice method under undrained condition. The excel spreadsheet developed in the study is mainly divided into two forms i.e. deterministic model worksheet for calculating the factor of safety and uncertainty model for generating the random variables of uncertain parameters. The undrained shear strength is considered as an uncertain parameter. The nominal factor of safety value is found out to be 1.248 and the critical slip circle has coordinate (2.6, 8.8), having radius of 16 m. The reliability index is found out using FOSM, FORM and MCS.

Soil-Structure Interaction (SSI) issues are some of the most critical problems encountered in the design of structures prone to earthquake shaking. The damage caused by an earthquake mainly depends on the interaction between soil and structure. In this study, the effect of dynamic SSI on a multi-story building is examined using two methods, Finite Element Method (FEM) and Minimax Probability Machine Regression (MPMR). The MPMR was used to develop a model based on the input and output database generated from the FEM model. The performance comparison of these two models shows a good correlation. The MPMR model significantly reduced the computational time and can thus be utilized as a substitute for determining the response quantities.