(SEM V) THEORY EXAMINATION 2024-25 ENGINEERING GEOLOGY

Subject Code: BCE054
Maximum Marks: 70
Time: 3 Hours
Paper ID: 310890

Question Paper Overview

SECTION A (2 × 7 = 14 Marks)

(Short conceptual questions — definitions and fundamentals)

a. What are the major branches of geology that contribute to civil engineering?
b. Explain the role of mineralogy in civil engineering projects.
c. What are the basic physical properties of minerals?
d. What is an outcrop, and how is it related to topography?
e. Explain the process of erosion and its effects on rock formations.
f. What is the significance of a geological survey in selecting bridge sites?
g. Explain the concept of an artesian well and its importance in water management.

SECTION B (Attempt any three × 7 = 21 Marks)

(Medium-length descriptive questions)

a. Describe the structure and texture of igneous rocks and their use as building materials.
b. Explain the classification of faults and how each influences construction.
c. Discuss the causes and prevention of landslides in hilly regions.
d. Explain the significance of dip and strike in geological mapping and their engineering applications.
e. Discuss the role of the Geological Survey of India (GSI) and NIRM in geological investigations in India.

SECTION C (Attempt one part from each question × 7 = 35 Marks)

Q3.
(a) Explain how classification of rocks based on texture and origin helps in selecting materials for construction.
OR
(b) Discuss the process of weathering and the factors influencing it, especially in construction contexts.

Q4.
(a) Describe types of folds in rock formations and their impact on construction stability.
OR
(b) Discuss the geological considerations for selecting a reservoir site, focusing on rock and soil factors.

Q5.
(a) Explain the importance of studying rock deformation for civil engineers, especially in earthquake-prone areas.
OR
(b) Explain the geophysical exploration methods used to study subsurface structures.

Q6.
(a) Define an aquifer and discuss its role in groundwater management with examples.
OR
(b) Explain the classification of seismic zones in India and their relevance to construction safety.

Q7.
(a) Discuss the engineering properties of common building stones and their suitability for large-scale projects like dams and bridges.
OR
(b) Explain the concept of unconformities and their significance in geological hazard assessment.

Key Topics for Revision

1. Branches of Geology

Petrology: Study of rocks.

Mineralogy: Composition & properties of minerals.

Structural Geology: Study of rock structures (folds, faults).

Geomorphology: Study of surface landforms.

Hydrogeology: Study of groundwater.

Engineering Geology: Application of geological principles in civil works.

2. Minerals & Rocks

Physical properties: Hardness, colour, luster, streak, cleavage, specific gravity.

Rock types:

Igneous (granite, basalt) – strong, durable.

Sedimentary (sandstone, limestone) – layered, porous.

Metamorphic (gneiss, marble) – hard, good for buildings.

Texture & Structure: Affect strength, permeability, and suitability for construction.

3. Geological Processes

Weathering: Disintegration of rocks by physical, chemical, or biological agents.

Erosion: Removal of material by water, wind, or ice – weakens slopes.

Outcrop: Visible exposure of bedrock – helps in geological mapping.

4. Geological Structures

Folds: Bending of strata – anticline & syncline. Important for tunnel and dam alignment.

Faults: Fractures causing displacement – can cause leakage or instability.

Dip & Strike: Indicate inclination and orientation of rock beds.

5. Geological Hazards

Landslides: Triggered by heavy rainfall, steep slopes, earthquakes.

Prevention: Retaining walls, vegetation, drainage control.

Earthquakes: Understanding seismic zones (Zone II–V) is vital for structural design.

6. Groundwater Geology

Aquifer: Water-bearing permeable rock layer (e.g., sandstone, gravel).

Types: Confined, unconfined, perched.

Artesian Well: Natural pressure allows water to rise without pumping.

Water Table: Boundary between saturated and unsaturated zones.

7. Geophysical Exploration Methods

Seismic method: Detects subsurface structures by analyzing wave reflections.

Electrical resistivity: Determines groundwater levels.

Magnetic & Gravity methods: Identify ore bodies and structural variations.

8. Geological Surveys in India

GSI (Geological Survey of India): Mapping, resource exploration, hazard assessment.

NIRM (National Institute of Rock Mechanics): Rock testing and geotechnical studies for tunnels, dams, and mines.

9. Building Stones in Civil Engineering

Common types: Granite, basalt, limestone, marble, sandstone.

Engineering properties: Strength, hardness, porosity, durability, appearance.

Applications:

Granite – bridges, foundations.

Limestone – decorative works.

Basalt – roads and dams.

10. Unconformities

Surfaces separating rocks of different ages → represent a time gap in deposition.

Important in identifying geological hazards and structural discontinuities before construction.