Geotechnical Engineering is concerned with the engineering behaviour of earth materials ( soils and rocks) on which(& in which) man made structures rest and it involves determining various properties of soils and rock through laboratory and field testing , assessment of site conditions , Field investigations, analysis and design of various structures ( say for example, slopes, foundations, canals, tunnels etc) based on analytical methods or numerical modelling solutions( for example, Finite Element Analysis, Finite Difference Method, Boundary Element Method etc) .