JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech II ENGINEERING GEOLOGY Previous Question Paper (July/August - 2021 - R16)

Physical Geology deals with the study of geological processes such as weathering, erosion, sedimentation, and volcanic activity. It is essential for understanding the surface features of the earth and the dynamic forces that continuously modify the landscape, which is critical for site selection and assessing natural hazards like landslides.

Petrology is the study of rocks, including their origin, composition, structure, and classification. It is fundamental in engineering because the physical and chemical properties of rocks—such as strength, durability, and permeability—directly influence the stability of foundations, tunnel excavation, and the suitability of rocks as construction materials.

Structural Geology focuses on the deformation of rocks, including folds, faults, joints, and unconformities. It is vital for civil engineering projects because these structural features can create zones of weakness, influence groundwater flow, and affect the stability of slopes and dam foundations, necessitating detailed mapping before construction.

Weathering is the natural process of physical disintegration and chemical decomposition of rocks at or near the Earth's surface due to exposure to atmospheric agents like water, temperature fluctuations, oxygen, and biological activity. It transforms solid rock into loose, unconsolidated material known as regolith or soil.

The significance of weathering in engineering construction includes:

• Foundation Stability: Weathered rock often has lower bearing capacity and higher compressibility, which can lead to differential settlement of structures.
• Slope Stability: Weathering reduces the shear strength of rock masses, increasing the risk of landslides and rockfalls in hilly terrains.
• Material Selection: Highly weathered rocks are generally unsuitable for use as aggregate in concrete or as building stone due to their lack of durability.
• Excavation Costs: The depth of the weathered zone (overburden) determines the cost and method of excavation; deeper weathering requires more extensive removal before reaching sound bedrock.
• Groundwater and Seepage: Weathering increases the porosity and permeability of rock, which can lead to increased seepage in reservoirs and dams.