Analysis and simulations of erosion protection designs using the PLAXIS 2D and Slide programs

Abstract

Along the zone of interaction between land and water, there are continually changes due to dynamic interaction of water and land, so lots of problems occur such as Erosion, flooding, etc. Therefore riverbank and flood protection structures have become useful in the past decades. The National Road NR.01B is built along the mountainous area below the road is a river which flow parallel to the road alignment in soft shale area. There are 4 different stations which were investigated at KM90+600, KM 92+125, KM 92+212.5 and KM92+512.5. Unusually heavy monsoon rains, exacerbated by tropical storms, have caused widespread flooding in more than 60 per cent of the Lao PDR from late June through August. The monsoon rains continued since, and the country endured almost continuous heavy rainfall for some ten weeks. The forensic solution for erosion along the National Road is to use geosynthetic for improving the stability of the erosion protection structures. PLAXIS FEM 2D analysis was utilized to predict factor of safety for each station in case of low water and high water level. In each station of erosion protection structure used same soil parameter due to the same locations. The Slide Software was utilized to predict the value of factor of safety using Bishop, Janbu and Spencer methods in both cases of water level for each flood and erosion protection structure by using the same soil and support parameters which was used in PLAXIS FEM 2D Software. Moreover, comparing the best station between each erosion protection structures were carried out. Furthermore, comparing the results from PLAXIS FEM 2D and Slide Software, the result from PLAXIS 2D seems to have higher accuracy.