Reliability Analysis of Liquefaction for Some Regions of Bihar

2018 ◽  
Vol 9 (2) ◽  
pp. 23-37
Author(s):  
Sujeet Kumar Umar ◽  
Pijush Samui ◽  
Sunita Kumari
Keyword(s):  
Reliability Analysis ◽  
Soil Liquefaction ◽  
Liquefaction Potential ◽  
First Order ◽  
Seismic Liquefaction ◽  
Method Factor ◽  
First Order Second Moment ◽  
Assessment Measures ◽  
Bihar State ◽  
Liquefaction Assessment

There are many deterministic and probabilistic liquefaction assessment measures to classify if soil liquefaction will take place or not. Different approaches give dissimilar safety factor and liquefaction probabilities. So, reliability analysis is required to deal with these different uncertainties. This paper describes a reliability technique for predicting the seismic liquefaction potential of soils of some areas at Bihar State. Here a reliability approach has been presented in order to find the probability of liquefaction. The proposed approach is formulated on the basis of the results of reliability analyses of 234 field data. Using a deterministic simplified Idriss and Boulanger method, factor of safety of soil has been accessed. The reliability index as well as corresponding probability of liquefaction has been determined based on a First Order Second Moment (FOSM) method. The developed method can be used as a robust tool for engineers concerned in the estimation of liquefaction potential.

scholarly journals Liquefaction potential mapping of Newtown, Kolkata, India using Deterministic and Reliability analysis

2021 ◽  
Author(s):  
Srijani Sett ◽  
Kalyan Kumar Chattopadhyay
Keyword(s):  
Reliability Analysis ◽  
Reliability Index ◽  
Parameter Uncertainties ◽  
Borehole Data ◽  
Liquefaction Potential ◽  
First Order ◽  
Contour Maps ◽  
First Order Second Moment ◽  
Potential Mapping ◽  
Soil Losses

Abstract Liquefaction is a phenomenon where the effective stress of the soil gets reduced to zero and the soil losses its shear strength completely. Such occurrence is common during an earthquake and hence the need for evaluating the liquefaction potential of soil arises. The region of Newtown-Rajarhat is undergoing a massive industrial and residential growth and as the area has layers of sand and silt mixed with clay and organic matter, it is essential to determine its liquefaction potential. In this study, the deterministic methods proposed by Youd et al. (2001) and Boulanger and Idriss (2014) were utilized to evaluate the liquefaction potential of the region using 102 borehole data for earthquake magnitudes of 6 and 7. However it was observed that both methods gave different results for the same input parameters. The parameter uncertainties were identified and a reliability analysis was performed to represent the liquefaction potential in terms of reliability index and probability of liquefaction. The First-Order-Second-Moment (FOSM) method was utilized here and contour maps were prepared for depths of 7m and 13m for both the earthquake magnitudes. It was concluded that the study area is vulnerable to liquefaction at a depth of 13m in the regions of Newtown, Rajarhat and Sector V.

Reliability analysis of a structural element based on the Advanced First-Order-Second-Moment Method.

1985 ◽  
Vol 51 (472) ◽  
pp. 2811-2816
Author(s):  
Yoshisada MUROTSU ◽  
Masaaki YONEZAWA ◽  
Hiroo OKADA ◽  
Satoshi MATSUZAKI ◽  
Toshiki MATSUMOTO
Keyword(s):  
Reliability Analysis ◽  
Moment Method ◽  
Structural Element ◽  
Second Moment ◽  
First Order ◽  
First Order Second Moment ◽  
Second Moment Method

Probabilistic Assessment of Soil Liquefaction by Using Seismic Chinese Code

2012 ◽  
Vol 166-169 ◽  
pp. 2248-2252
Author(s):  
Sanguan Vongchavalitkul ◽  
Swein Kumpangta
Keyword(s):  
Safety Factor ◽  
Factor Of Safety ◽  
Standard Penetration Test ◽  
Soil Liquefaction ◽  
Probabilistic Assessment ◽  
Probability Method ◽  
Deterministic Method ◽  
Actual Measurement ◽  
First Order ◽  
First Order Second Moment

Deterministic safety factor are introduced by Z. CAO et al (2008) according to seismic Chinese code. The approach was deterministic method used the standard penetration test (SPT) to evaluate the liquefaction of soil. With this method, liquefaction of soil is predicted to occur if the factor of safety(FS), which in the ratio of critical SPT-N value(Resistance) over the actual measurement SPT-N(Load), is less than or equal to one. If the factor of safety greater than one, no soil liquefaction is predicted. Because the significant uncertainties in variable involved in the deterministic factor of safety, the probability method need to use. Probabilistic safety factor calculations provide a means of evaluating the combined effeces of uncertainties and provide a logical framework for choosing a factor of safety that is appropriate for the degree of uncertainty and consequences of failure. Then, a probabilistic assessment of soil liquefaction may be performed in which probability of failure and reliability index. By using the most widely reliability analysis as the First Order Second Moment (FOSM) method, the results of a probabilistic assessment of soil liquefaction can be used for engineering decision.

A New Model of Stochastic Crack Growth under Random Loading and Reliability Analysis of Fatigue Life

2007 ◽  
Vol 353-358 ◽  
pp. 81-84
Author(s):  
Hong Zhong Huang ◽  
G. Huang ◽  
Qiang Miao ◽  
Dan Ling ◽  
Q. Ma
Keyword(s):  
Reliability Analysis ◽  
Crack Growth ◽  
Critical Size ◽  
Crack Size ◽  
Initial Crack ◽  
Random Loading ◽  
New Model ◽  
First Order ◽  
Moment Approximation ◽  
First Order Second Moment

A new model is proposed for the analysis of fatigue crack growth under random loading. The fatigue rule of crack length is transformed into the monotony function rule based on types of the crack. By performing reliability analysis, the randomness of the stress, the stochastic nature of the crack growth, the fuzziness of the initial crack size and the randomness of the crack critical size are considered. The First-order-second-moment approximation method is used to obtain the solution of the probability density function. An example is given to illustrate feasibility of the proposed method.

scholarly journals Reliability Analysis Approach For Intersection Sight Distance Of A Symmetrical Single-Lane Roundabout

2021 ◽  
Author(s):  
Paria Sarshar
Keyword(s):  
Reliability Analysis ◽  
Safety Margin ◽  
Random Variables ◽  
Analysis Approach ◽  
Deterministic Models ◽  
Second Moment ◽  
First Order ◽  
Sight Distance ◽  
Design Variables ◽  
First Order Second Moment

The current intersection sight distance values on a roundabout provided by ASSHTO and other worldwide guidelines are based on deterministic methods considering only single variables as the design inputs. However, most of the input design variables such as entering speed and the deceleration rate are random variables which are stochastic in nature. Therefore, this study proposes a reliability analysis approach to add uncertainty to the current deterministic models. Two different reliability approaches; the first order second moment and advanced first order second moment are presented in this paper. These approaches rely on the normal distribution of the random variables using the mean, variance and the covariance of the probability distribution of each variable rather than the single deterministic values. Results show that the AFOSM reliability methodology provides a more conservative outcome which ensures a greater safety margin comparing to FOSM which appears to be a more efficient and robust methodology.

scholarly journals Reliability analysis of truck escape ramp design

2021 ◽  
Author(s):  
Kaitlyn Ann Greto
Keyword(s):  
Reliability Analysis ◽  
Safety Margin ◽  
Rolling Resistance ◽  
Second Moment ◽  
First Order ◽  
Stopping Distance ◽  
Design Variables ◽  
Reliability Method ◽  
First Order Second Moment ◽  
Design Speed

The truck escape ramp design presented by the Transportation Association of Canada is based on deterministic values of the design variables which include the required stopping distance, design speed, rolling resistance, and grade. Currently, a reliability analysis of the design of truck escape ramps does not exist. This report presents two methods used to analyze the reliability of truck escape ramp design; the first order second moment reliability method and the advanced first order second moment reliability method. These methods do not rely on deterministic values rather the mean and variance (moments) of each random variable’s probability distribution. Each reliability method was used to analyze truck escape ramps with one grade and two grades, for a total of four cases. The results of each case are provided and discussed along with an application to two existing truck escape ramps. The results show that the advanced first order second moment reliability method ensures more accurate results as well as a larger safety margin in comparison to the first order second moment method due to the nature of the methodology itself which considers design points.

scholarly journals Reliability Analysis Approach For Intersection Sight Distance Of A Symmetrical Single-Lane Roundabout

2021 ◽  
Author(s):  
Paria Sarshar
Keyword(s):  
Reliability Analysis ◽  
Safety Margin ◽  
Random Variables ◽  
Analysis Approach ◽  
Deterministic Models ◽  
Second Moment ◽  
First Order ◽  
Sight Distance ◽  
Design Variables ◽  
First Order Second Moment

The current intersection sight distance values on a roundabout provided by ASSHTO and other worldwide guidelines are based on deterministic methods considering only single variables as the design inputs. However, most of the input design variables such as entering speed and the deceleration rate are random variables which are stochastic in nature. Therefore, this study proposes a reliability analysis approach to add uncertainty to the current deterministic models. Two different reliability approaches; the first order second moment and advanced first order second moment are presented in this paper. These approaches rely on the normal distribution of the random variables using the mean, variance and the covariance of the probability distribution of each variable rather than the single deterministic values. Results show that the AFOSM reliability methodology provides a more conservative outcome which ensures a greater safety margin comparing to FOSM which appears to be a more efficient and robust methodology.

Reliability Analysis of Circular Footing by Using GP and MPMR

2021 ◽  
Vol 12 (1) ◽  
pp. 1-19
Author(s):  
Rahul Kumar ◽  
Pijush Samui ◽  
Sunita Kumari ◽  
Yildirim Hüseyin Dalkilic
Keyword(s):  
Bearing Capacity ◽  
Reliability Analysis ◽  
Unit Weight ◽  
Variable Parameters ◽  
Angle Of Internal Friction ◽  
First Order ◽  
Moment Methods ◽  
First Order Second Moment ◽  
Minimax Probability Machine Regression ◽  
Circular Footing

Circular footings are designed to bear a load of super structures. Studies have been done on the influence of soil properties on bearing capacity of shallow foundations. The use of circular foundation is practical in geotechnical engineering. During the design of circular footing, bearing capacity of soil is taken into consideration, and cohesion (c), unit weight (γ), and angle of internal friction (ϕ) are the most variable parameters. Reliability analysis is used frequently for the design of circular footing. Most of the authors have used first order second moment methods (FOSM). However, FOSM is a time-consuming method. Drawbacks of FOSM have been overcome by genetic programming (GP), minimax probability machine regression (MPMR). This article gives a distinct analysis between the developed MPMR based FOSM and GP-based FOSM.

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