PROBABILITY ANALYSIS OF RETAINING WALL ON SAND IN WATER TABLE DEPTH VARIATION

Abstract

Deterministic analysis of retaining wall only takes account single soil properties that represent the whole data of soil. In contrary, probabilistic analysis accommodate the presence of variability by using all data of soil properties in a Monte Carlo method. The newest method is now widely applying in many geotechnical structure designs. This paper focuses on the analysis of retaining wall on sand using probabilistic analysis in a variation of water table depth. Retaining wall was sit in Jamuna River Sand and the depth of water table are 1 m and 3 m below soil surface respectively. The analysis begins by carrying conversion of tip resistant (q ) to friction angle, follows by representing the fit distribution of friction angles data in a form of Normal, Lo-normal, Beta, and Gamma distribution by ready program written in MATLAB. As statistics parameters derived, retaining wall was analyzed to determine the safety factor against sliding, overturning, and soil bearing capacity, by computer aid of Crystal Ball. Finally, the result of probabilistic analysis was compared to the conventional analysis. The result shows that both variations of retaining wall are unsafe in terms of sliding, overturning, and soil bearing capacity stabilities, either probabilistic and conventional analysis.