Numerical analysis of an unsymmetrical railcar unloading pit and connection trench

A numerical analysis was performed simulating the deep excavation and dewatering effects on retaining walls of an unsymmetrical railcar unloading pit and trench. With a depth of 22 meters and an internal diameter of 45 meters the circular pit has a 12 meters width connecting with the trench, which is non collinear with the pit center. A 3D Finite Element Model using PLAXIS software was conducted in order to access both general and local effects in the design of the pit structural elements, due to singularities introduced by the trench opening on the west side of the pit wall and the trench excavation. Both geotechnical and hydrogeological characteristics of site were considered as well as the main construction stages covering the excavation sequence and the groundwater flow analysis.