The Stability Investigation of Flood Wall Structure Using Plaxis 2D

Abstract

Nava Nakorn Industrial is a home of world-class companies that serves many types of industries located in Pathumthani Province, Thailand with an area of more than 10 km2. In 2011, the natural disaster, flooding up to about 4.7 m for 2 months caused the impacts in this industrial zone. The permanent flood wall protection was then built around the industrial area to ascertain the safety and to build the confidence for the investors. The evaluation of the safety and stability of the flood wall against the flooding problem is carried out in this research and divided into three main assessments, including site investigation and soil exploration, examination of the existing flood wall structures, and finite element analysis of its stability using Plaxis 2D. The site investigation and soil exploration, included boring, Atterberg limits, consolidation and triaxial tests to explore the basic and engineering parameters. The mechanical tests, including Schmidt Hammer test, Ferro scan test, Hardness test, as well as coring and compressive strength test of concrete were conducted. The finite element analysis results showed that the external factor of safety at a water level of +5.20 m (MSL) over a 4 months period was 6.717 higher than the designer specified at 1.50. Meanwhile, the bending moment and shear force values were 6.185 kN-m/m and 6.697 kN/m, respectively, which are lower than the allowable bending moment and shear force of 17.50 kN-m/m and 62.10 kN/m. In other words, the internal factor of safety against bending moment and shear force were 2.83 and 9.27, respectively. As such, the flood wall protection provides sufficient internal and external stability with low water permeability under the foundation of the flood wall for a period of 4months at water level at +5.20 m. This research confirms there is no impact on the rise of water level within the studied area due to the flooding problem for a period of 4 months.