RELIABILITY ANALYSIS OF DAMPALIT MEGA DIKE USING MONTE CARLO SIMULATION AGAINST SLIDING FAILURE

Abstract

The main purpose of coastal defenses is to mitigate the effects of an increased rise in sea levels and the abrupt changes in storm surges brought upon by various uncertainties. Evaluation of the Dampalit Mega Dike’s resistance against sliding failure using Reliability Analysis provides an avenue for considering these uncertainties that would affect the structural safety of the dike. In this study, random variables, including the angle of friction, water level, and wind speed, were considered as the parameters in determining the dikes’ probability of failure. Wave action and storm surges were considered, which were vital since these would greatly affect the resistance of the dike. A deterministic approach was initially performed using PLAXIS 2D to compare the conventional design and analysis with a probabilistic approach. For the probabilistic method, both serviceability (SLS) and ultimate limit states (ULS) were evaluated with 100,000 iterations using Monte Carlo Simulation wherein results show a probability of a failure of 0.54 for SLS and 0.86 for ULS. The significant deviation from the acceptable value of x 10^-3 to the computed values highlights a potentially critical issue in the structural system or the underlying assumptions used in the analysis. A high risk of failure in terms of sliding was concluded, however, biases were observed in the data since no correlations were found between the variables. Moreover, to increase the soil stability of the dike, an additional embankment on the seaward side was recommended to improve the resistance against sliding failure of the dike.