appearance and properties resulting from weathering of a parent earth - PowerPoint PPT Presentation

IIT Bombay Slide 3 “a natural body, separated into horizons of different appearance and properties resulting from weathering of a parent earth material” A Organic and leached (very Active/Instable phase) B Accumulation of fines (Active phase) “topsoil” C “subsoil” or original parent material (geological) soil (Dormant phase) Environmental Geomechanics Lecture No. 3-4-5-6 D N Singh

IIT Bombay Slide 4 “ any uncemented or weakly cemented accumulation of mineral particles formed by the weathering of rocks, the void spaces between the particles containing water and/or air” (Minerals, Air, water---------A live material) A PARTICULATE MATERIAL, REGARDLESS OF MINERAL OR ORGANIC COMPOSITION, THAT REACTS TO EXTERNAL FORCES BY THE INTERACTION BETWEEN INDIVIDUAL PARTICLES/GRAINS Environmental Geomechanics Lecture No. 3-4-5-6 D N Singh

IIT Bombay SOIL: A LIVING ENTITY Slide 5 Hence quite susceptible & Sensitive to the Environment in which it stays just like Human (living) beings Heritage Parentage …….. Rock cycle Linkage Genetics Memory Emotions Response to external stimulus Environmental Geomechanics Lecture No. 3-4-5-6 D N Singh

Panc anch h Tatva tvas (E s (Element lements) s) IIT Bombay Slide 6 of of J Jee eevan ( van (Lif Life) e) Kshitij Kshitij (Horiz (Horizon) on) Infinity Gagan (Sk Ga gan (Sky) y) Formation of Pavak (Fir vak (Fire) e) soil Jal (W al (Water) ter) Deposition & Sameer (Air) Sameer (Air) Transportation of soil Environmental Geomechanics Lecture No. 3-4-5-6 D N Singh

IIT Bombay Slide 7 A Boulder >12” C Cobble >6” T S Experience Gravel >4.75mm I O V Sand >0.075mm I I Silt >0.075mm L T Clay >0.002mm Y Organic matter Environmental Geomechanics Lecture No. 3-4-5-6 D N Singh

IIT Bombay Soil: particulate, much more complex than Slide 8 steel & its Behavior is influenced by: • Soil type (grain size, shape, minerals etc.) • Water, Air, content • Electro-chemical effects • Climate (humidity, temperature, pressure, permafrost) • Stress history (of loading and unloading, N.C., O.C. behavior) • Still much more (& better) predictable & workable than the living beings (who originate from it) Environmental Geomechanics Lecture No. 3-4-5-6 D N Singh

IIT Bombay Slide 9 SYMPTOMS COMMON TO HUMANS & SOILS Obesity Expansive soil Aneroxia Shrinkage High B.P. Excess pore water pressure Giddiness Instability Epilepsy Liquefaction Fractures Failures/collapse of foundations retaining walls, piles etc. Cyclic loading Fatigue Drainage Urinary problems Environmental Geomechanics Lecture No. 3-4-5-6 D N Singh

IIT Bombay Slide 10 Challenges and Concerns?? Geotechnical Engineering Professionals are involved with: Diagnostics [of Symptoms & Abnormalities] + Prescription [adequate corrections] + Prolonged Monitoring (Effectiveness of Prescription) Environmental Geomechanics Lecture No. 3-4-5-6 D N Singh