SOIL MECHANICS STUDIES THE STRUCTURE ENGINEERING PROPERTIES AND CONTAIN AIR WATER AND SOLIDS, MIXTURE OF MINERAL MATTERS WITH PARTICLES DIFFERING IN, SIZE, SHAPE AND STRUCTURE AND VARYING IN CHEMICAL COMPOSITION

Soil is the naturally occurring loose or soft deposit forming part of the earth's crust, produced as a result of weathering or disintegration or decomposition of rock formations or decay of vegetation intermingled together. The top layer of the ground that supports vegetation is called soil or the top soil and the undisturbed strata lying immediately below the natural top soil is termed sub-soil. Soils contain three components, viz, air, water and solids. The solids are a mixture of mineral matters with particles differing in size, shape and structure and varying in chemical composition. There are six main soil types ie Gravels, sands, silts, clays, fine grained organic soils and peat. In view of the wide diversity of soil types they have been classified into groups or classes according to their particles size and cohesive properties. Clays, shales and silts are classified as cohesive soils (true silt has little cohesion) Sands and gravels are classified as non -cohesive or cohesionless soils as they possess no plasticity and tend to lack cohesion specially when in the dry state. As such it is necessary to follow branch of Soil mechanics science which studies the structure engineering properties and the reaction or behavior of the soils under loading and the changing weather conditions. The main function of the soil studies is to furnish some general principles to supplement and guide the practical experience and free judgement of the Engineer, although it cannot give an exact solution to every practical problem. Detailed studies of characteristics of a soil are useful in predicting the performance of the soil under load, which depends upon the grain size, shape, surface texture and chemical composition. The property having most influence on the physical characteristics is that of particle-size distribution, and therefore, it is essential to determine the extent to which each is present:-- Er Fateh Chand Guleria, RTI welfare Association registered number HPCD, 3552 , Bilaspur Himachal pradesh phone number, 9459334377.