Retaining structures for supporting deep excavation have a key role in ensuring stability and safety in various industrial projects. Due to the large area, selection of the supporting system is also a challenging task. A comprehensive study of arrangement, analysis and design of sheet pile as a retaining structure in large-scale deep excavation (900 m2) has been presented in this paper. The soil strata in that area consist of silty clayey soil up to a depth of 6 m followed by dense silty sand. This system was proposed and executed at Numaligarh Refinery Limited in Assam, India. The study involves various geotechnical considerations and the overall behaviour of sheet piles in deep excavation using finite element method-based software. The soil has been modelled as springs in STAAD.PRO to get the forces acting on sheet pile due to earth pressure and hydrostatic pressure. The optimum sheet pile section along with the supporting arrangement with walers and inclined struts at various angles has been arrived based on the forces so obtained and the market availability of various components at site. The same shoring system has been modelled in GEO5 to get the numerical results related to the expected sheet pile behaviour and the effectiveness of the sheet pile system to prevent the soil collapse under the lateral earth pressure. This paper also describes the proper dewatering system to be adopted at site and other construction practices. Various implications of selecting this particular type of large-scale deep excavation support system have also been discussed which contributes to the better understanding of practising engineers and researchers.