1.Introduction to Soil Mechanic Subject.pptx

Soil Mechanics

1. Soil Mechanics

2. Introduction Total = 50( Theory) Theory Paper = (Mid + Final)=(10+30) Sessional Marks= 10 Assignment-I = 3 Class Test-I =2 Assignment-II = 2 Class Test-II =3

3. Introduction CLO Description Taxonomy Level PLO 1 DEMONSTRATE index properties of soils and carry out classification of soils C4 2 2 GET ACQUAINTED with clay minerology and clay chemistry. C1 1 3 ANALYZE the range of soil related problems especially those involving seepage of water through Soil. C4 2

4. Soil Mechanics Soil is the mixture of minerals, organic matter, gases, liquids and the countless organisms that together support life on Earth. Soil is considered to be the skin of the earth.

5. Composition of Soil

6. What is Soil ? For Engineer A natural aggregate of mineral grains, loose or moderately cohesive, inorganic or organic in nature.

7. For Geologist Disintegrated Parts of rocks.

8. For Agriculturist The loose mantle at the surface of the earth which favors the growth of Plant.

9. What is Soil ? For an Environmental Engineer. Water Management: Groundwater Protection: Soil mechanics helps in understanding how different soil types affect the percolation and infiltration of water through the ground. This knowledge is crucial in protecting groundwater resources from contamination and ensuring safe drinking water sources. Drainage and Erosion Control: Soil properties determine drainage behavior and erosion susceptibility. Proper soil mechanics knowledge allows for the design of effective drainage systems and erosion control measures, preventing environmental damage due to soil erosion.

10. What is Soil ? For an Environmental Engineer. Geotechnical Aspects of Waste Management: Landfills and Waste Disposal: Properly engineered landfill structures rely on soil mechanics principles to ensure stability, prevent leachate migration, and minimize environmental contamination risks Waste Containment: Understanding soil behavior is critical in designing containment systems for waste disposal facilities, preventing the migration of pollutants into the surrounding environment. Leachate: water that has percolated through a solid and leached out some of the constituents.

11. What is Soil ? For an Environmental Engineer: SO….. In essence, soil mechanics provides the foundational understanding necessary for planning , designing , and executing environmentally sensitive projects. It’s an indispensable tool in managing environmental challenges and ensuring the sustainability of engineering solutions within our ecosystems.

12. Soil Mechanics is defined as the branch of engineering science which enables an engineer to know theoretically or experimentally the behavior of soil under the action of Loads (static or dynamic) Gravitational forces Water Temperature Soil Mechanics

13. Soil Mechanics Soil Mechanics is the branch of science that deals with study of physical properties of soil and behavior of soil masses subjected to various types of forces. Engineer’s must study the properties of Soil , such as its origin, grain size distribution, ability to drain water , compressibility, shear strength, and load bearing capacity. Ability of Draining Water: Permeability (that’s why we (Environmental Engineers) are so interested about).

14. Soil Mechanics Engineer’s must study the properties of Soil , such as its Origin grain size distribution Ability to drain water Compressibility Shear strength Load bearing capacity

15. Karl Terzzaghi (1883 - 1963) Karl Terzaghi has often been called the BABA (father) of Soil Mechanics. Academically, he earned an Undergraduate degree in Mechanical Engineering. In 1925, he accepted lectureship at MIT. In 1939, he accepted professorship at Harvard University till his death.

16. SOIL AS A NATURAL MATERIAL Unfortunately, soils are made by nature and not by man, and the product of nature are always complex. Natural soil is never uniform. Its properties changes from point to point while our knowledge of its properties are limited to those few spots of which the samples have been collected.

17. Why we study Soil Mechanics? Virtually every structure is supported by soil or rock. Various reasons to study the properties of Soil : Although WE have talked about various reason BUT…. Lets see few more reasons Foundation to support Structures and Embankments Construction Material Slopes and Landslides Earth Retaining Structures Special Problems

18. Various reasons to study the properties of Soil: Foundation to support Structures and Embankments Effects of static loading on soil mass Shear failure of the foundation soil Settlement of structures Stability criteria (Solution) There should be no shear failure of the foundation soil. The settlement should remain within permissible limits.

19. Why we study Soil Mechanics? Foundation to support Structures and Embankments Effects of dynamic loading on soil mass For Design and construction of roads following must be considered: Compaction Characteristics Moisture Variation

20. Why we study Soil Mechanics? Various reasons to study the properties of Soil : Construction Material Subgrade of highway pavement Land reclamation (Dubai Palm City) Earthen dam

21. Why we study Soil Mechanics? Various reasons to study the properties of Soil : Slopes and Landslides Major cause is the moisture variation resulting in; Reduction of shear strength Increase of moisture Increase in unit weight Excavation of trenches for buildings require braced excavation.

22. Why we study Soil Mechanics? Landslide of a parking area at the edge of a steep slope, mainly due to increase in moisture content .

23. Why we study Soil Mechanics? Various reasons to study the properties of Soil : Special Problems Effects of river water on soil mass Scouring Causes: Increased flow velocity due to obstruction Fineness of riverbed material Stability criteria: The foundation of pier must be below the scour depth Land Erosion

24. Why we study Soil Mechanics? Various reasons to study the properties of Soil : Special Problems Effects of frost action on soil mass Reduction Of Shear Strength Settlement Of Structure In Summer Lifting Up Of Structure In Winter Causes: Heaving (due to formation of ice lenses) Increase of moisture due to thawing (MELTING )

25. Engineering Soil Surveys Soil Sampling Devices and Methods Soil Testing Devices and Methods Physical Properties of Soil Evaluation and Interpretation of Test results Behavior under Loads and Forces Sedimentation Control of Dam Reservoirs Design and Operation of Landfills Objectives of Soil Mechanics