Assessment of Safety Factor of River Roof with Considering a Variation of Input Parameters as Bulk Unit Weight, Cohesion, Friction Angle and Water Level

The rapidly growing development of the Mekong Delta leads to the needs of infrastructure as well as road constructions for trading. The roads are mainly built along rivers and canals. However, riverbank erosion in the Mekong Delta caused by geological characteristics, hydrological characteristics and so on is becoming more and more complicated. Therefore, in this paper, the authors analyze the influence of changes of geological parameters such as bulk unit weight, cohesion, friction angle of the soil as well as water level on safety factor (FS) of the roads in Vinh Long City, Vinh Long Province. The variation of geological parameters is analyzed statistically from 15 constructions in Vinh Long City. Several statistical parameters such as mean, variance and standard deviation are used as input parameters, and then Monte Carlo simulation in GEOSTUDIO software is used to compute the failure probability of the roads. By using a combination of SIGMA/W, SEEP/W and SLOPE/W modules in GEOSTUDIO software, the paper comprehensively evaluates all factors affecting the safety factor of a riverside route. The results show that using only one parameter to design and calculate has a lot of potential risks. In fact, sliding failure has occurred at a few locations along the entire route although they have been reinforced with wooden piles. The computed results show that there is still a probability of 21.1% of landslide (FS < 1) in the research area while FS calculated by using a set of average parameters gives a value greater than 1.2.