Geotechnical Engineering Soil Mechanics Mr Sainand Khot Asst

Geotechnical Engineering/ Soil Mechanics Mr. Sainand Khot Asst. Professor DYPIEMR, Akurdi-44

Geo Technical Engineering • Meaning of geotechnical ? • What it has to do with engineering ? • Relation with civil engineering ? • Why it is called the mother of civil engineering ? By Mr. Sainand Khot DYPIEMR, Akurdi-44

Railways By Mr. Sainand Khot DYPIEMR, Akurdi-44

Roadways By Mr. Sainand Khot DYPIEMR, Akurdi-44

Foundation Failure By Mr. Sainand Khot DYPIEMR, Akurdi-44

Mining Engineering Failure By Mr. Sainand Khot DYPIEMR, Akurdi-44

Structural Failure due to Liquefaction By Mr. Sainand Khot DYPIEMR, Akurdi-44

Videos • Embankment failure due to the seepage flow and overburden pressure • Foundation failure By Mr. Sainand Khot DYPIEMR, Akurdi-44

Answers • Soil mechanics or geotechnical engineering is the application of laws of mechanics & hydraulics to engineering problems dealing with sediments and other unconsolidated accumulations of solid particles produced by the mechanical and chemical disintegration of rocks By Mr. Sainand Khot DYPIEMR, Akurdi-44

Applications in Civil Engineering 1. Foundation Design and Construction • Calculations of bearing capacity • Pattern of stress distribution under load • Settlement of foundation • Effect of ground water & vibrations • Suitability of foundation • Shrinkage & swelling characteristics By Mr. Sainand Khot DYPIEMR, Akurdi-44

2. Pavement Design • Type of pavement (rigid/flexible) • Thickness of subsoil • Consequent fatigue failure & effect of repetition of loading has to be taken in consideration of high intensity traffic By Mr. Sainand Khot DYPIEMR, Akurdi-44

3. Design of underground structures & earth retaining structures • Soil structure interaction is essential to design 4. Design of embankment & excavation • Shear strength & related By Mr. Sainand Khot DYPIEMR, Akurdi-44

5. Design of earth dams • Determination of soil properties like index properties, such as density, plasticity, specific gravity, particle size distribution and gradation of soil, permeability, consolidation and By Mr. Sainand Khot DYPIEMR, Akurdi-44

Types of Soil structure By Mr. Sainand Khot DYPIEMR, Akurdi-44

Major soil deposits of India Based on the climatic conditions, topography & geology of their formation following are the classifications • Alluvial Soils • Black Cotton Soils • Laterites and By Mr. Sainand Khot DYPIEMR, Akurdi-44 lateritic Soils

Alluvial Soils • formed mainly due to silt deposited by Indo-Gangetic. Brahmaputra rivers • They are immature and have weak profiles due to their recent origin • soil is porous because of its loamy (equal proportion of sand clay) nature • Porosity and texture provide good drainage and other conditions favorable for agriculture. • These soils are constantly By Mr. Sainand Khot DYPIEMR, Akurdi-44 replenished by the recurrent

Black Cotton Soils • parent material for most of the black soil are the volcanic rocks that were formed in the Deccan Plateau • These are the region of high temperature and low rainfall. It is, therefore, a soil group typical to the dry and hot regions of the Peninsula • black soil is highly argillaceous with a large clay factor, 62 per cent or more • black soils of uplands are of low fertility while those in the valleys are very fertile • black soil is highly retentive of moisture. It swells greatly on By Mr. Sainand Khot DYPIEMR, Akurdi-44 accumulating moisture

Laterites & lateritic Soils • Laterite soils are mostly the end products of weathering • formed under conditions of high temperature and heavy rainfall with alternate wet and dry periods. • Continuous stretch of laterite soil is found on the summits of Western Ghats at 1000 to 1500 m above mean sea level, Eastern Ghats, the Rajmahal Hills, Vindhyan, Satpuras and Malwa Plateau • They are well developed in south Maharashtra, parts of Karnataka By Mr. Sainand Khot DYPIEMR, Akurdi-44 etc.

Desert Soils • desert soils consist of Aeolian sand (90 to 95 per cent) and clay (5 to 10 per cent). • presence of sand inhibits soil growth. Desertification of neighboring soils is common due to intrusion of desert sand under the influence of wind • ccur in arid and semi-arid regions of Rajasthan, Punjab and Haryana. By Mr. Sainand Khot DYPIEMR, Akurdi-44

Marine Soils • Marine deposits are sediments that accumulate in a marine (ocean or sea) environment. • Marine deposits are predominantly of clay size (occasionally may contain some shells), very well sorted, devoid of coarse particles, and usually unstratified (show no layers). • These soils are found in narrow belt near the south. By Mr. Sainand Khot DYPIEMR, Akurdi-44

Field Identification of soils By Mr. Sainand Khot DYPIEMR, Akurdi-44

By Mr. Sainand Khot DYPIEMR, Akurdi-44

By Mr. Sainand Khot DYPIEMR, Akurdi-44

Soil Explorati • Objective: on To provide reliable, specific and detailed information about the soil and ground water conditions of the site which may be required • Purpose: for a safe and economic design and execution of the engineering work. • (i) To determine the basic properties of soil which affect the design and safety of structure i. e. , compressibility, strength and hydrological conditions. By Mr. Sainand Khot DYPIEMR, Akurdi-44

Different stages of sub-soil investigation of a major civil Engineering project • (i) Reconnaissance study: • (a) Geological data • (b) Serial photographs • (C) Pedological data • (ii) Detailed investigation: • (a) Boring • (b) Sampling • (c) Testing • • (i) Lab test (ii) Field test (d) Aerial photographs (e) Geophysical methods (iii) Performance study (a) Further testing (b) Instrumentation (c) Performance evaluation By Mr. Sainand Khot DYPIEMR, Akurdi-44

Thank You By Mr. Sainand Khot DYPIEMR, Akurdi-44