Geo-technical Stability and Sensitivity Analysis of Geo-synthetic Seawall at Pallana Beach, Kerala, India

Abstract

The various geo-synthetic components such as geo-tubes, geo-bags, geo-mattresses, geo-containers, geo-grids, geo-cells find extensive applications in coastal engineering practice. It is more sought after due to the ease of construction, quick implementation and reduced cost as the supply of natural rocks is eluded. Innovative geo-synthetic materials of numerous units were compounded to form a sea wall cross section, to be constructed at Pallana coast (9° 17′ 55.19″ N and 76° 23′ 18.55″) of Allepey, Kerala, to prevent wave run up during high tide level. The Pallana beach is also characterized with poor soil subgrade properties and hence the proposal to construct a geo-synthetic seawall in contrast to the conventional measures. The cross section is designed to ensure stability against overturning, sliding, overtopping and scour protection. The major concerns such as UV radiation, stability against wave action, settlement of the structure and protection against scour are to be addressed prior to the implementation of the design on site. The objective of the paper is to arrive at the significant geo-technical parameters responsible for the geo-technical stability of the structure over time. The pore-water pressures beneath the structure, rapid drawdown, transient stability and sensitivity analysis are computed for the above said structure using GeoStudio software application, which employs finite element method. A visualization of the geo-technical performance can be arrived that aids to verify the design parameters adopted.