This document provides an overview of soil mechanics. It defines soil and discusses its solid, liquid, and gaseous phases. Soil can be residual, formed from weathered parent rock, or transported by agents like water, wind, or glaciers. The document also examines soil classification and composition, discussing factors like particle size, mineralogy, voids, and cementation that influence soil behavior.

2. Soil Mechanics I CE-205 By Dr. S. Muhammad Jamil School of Civil and Environment Engineering National University of Sciences and Technology, Islamabad

3. Karl Terzaghi

6. SOIL MECHANICS In general sense of engineering, soil is defined as the un-cemented aggregate (or granular material) of mineral grains and decayed organic matter along with the liquid and gas that occupy empty spaces between the solid particles. All man made structures, except those which floats as fly, are supported by natural soil or rock deposits . What is Soil?

7. Soil mechanics is the branch of science that deals with the study of the physical and mechanical properties of soils and the behavior of soil subjected to various types of forces. In other words, soil mechanics is the study of both solids and fluid mechanical characteristics of soil. What is Soil Mechanics?

12. Road beds are often built of soil and the roadways themselves can often pass through mountain, cuts, fill etc. Understanding soil mechanics can preclude problems with pavement potholing and cracking, as well embankment and slope failure that can wipe out entire roadways . Transportation Engineering

14. The design of earthen flow retention structures such as dams, levees, dikes, storage ponds require knowledge of how water is transported through soil. How water flowing through soil can cause failure by mechanisms as boiling, piping, erosion and scouring. Hydraulic Engineering

15. SOIL MECHANICS Behavior of the Structure depends upon Properties of Soil on which the structure rests Properties of the rocks from which they are derived

19. When the solution of minerals is cooled more rapidly, tiny crystals of the minerals are formed in a vitreous matrix. For e.g. FELCITE – Extremely fine grained rocks. BASALT – When formed with ferromagnesium material s Igneous Rocks

20. Sedimentary rocks are from accumulated deposits of soil particles or remains of certain organisms that have become hardened by pressure or cemented by minerals. Due to abundant availability of cementing minerals such as silica, carbonates, iron oxides. For e.g. Limestones, Sandstone, Shale, Conglomerate and Breccia Sedimentary Rocks

21. Results when any type of existing rock is subject to metamorphism, the change brought about by combinations of heat, pressure and plastic flow so that the original rock structure and mineral composition are changed. [ -> Plastic flow – slow viscous movement and rearrangement within the rock mass due to external forces] Limestone -> -> MARBLE; Shale -> -> SLATE; Granite -> -> GNEISS; Sandstone -> -> QUARTZITE Metamorphic Rocks

22. SOIL MECHANICS ROCKS (IGNEOUS, SEDIMENTARY, METAMORPHIC) WEATHERING (PHYSICAL / CHEMICAL) TRANSPORTED BOULDERS, GRAVEL, SAND, SILT AND CLAY SOIL

23. Rocks whose chief mineral is quartz minerals with high silica content, decomposes to predominantly sandy or gravelly soil with little clay. [Acidic rocks are light-coloured] Basic rocks decompose to the fine-textured silt and clay soils. The clays are not small fragments of the original materials that existed in the parent rock [-> result of primary rock minerals decomposing to form secondary minerals]

32. In Soil (in most rock), voids exist between particles, and voids may be filled with a liquid, usually water or gas, usually air .