INTRODUCTION Geotechnical engineering is the branch of the civil engineering that concerns the application of the principle of mechanics ,hydraulics and to some extent chemistry ,it involves few really complicated solution of various problems in terms of equations but more important then that it consist some graphical solutions of various problems which are just based on the pure geometry and some of them are as ,,,, CULMANN'S GRAPHICAL METHOD This method is convenient for determining the active earth pressure of the soil having no cohesion. Morever it can be used for backfill surfaces of any shape,different types of surcharge load and even for a layered backfill. It consist of constructing the force triangle for the number of assumed trial failure plane. Procedure A line AF is drawn at an angle φ to the horizontal,this line is called as the slope line or weight line. Trial planes AC1,AC2 etc are drawn and weight of trial wedges are calculated ...