This document discusses the importance of engineering geology in dam construction. There are three main types of dams - arc or buttress dams, gravity dams, and embankment dams - which experience different forces. Proper geological investigations are required to ensure the stability and safety of the dam foundation, the water-tightness of the reservoir, and slope stability. Preliminary geological investigations include topographical studies, reservoir location analysis, petrology studies, structural geology studies, and examining foundation conditions. Detailed investigations involve making a detailed geological map, studying rock types, structures, seismic data, and interpreting core drill samples to understand the engineering geological properties of the area.

1. ENGINEERING GEOLOGY OF DAM
BY
Dr. V. R Ghodake
SCOE, Pune

2. Types of Dams
1. ARC OR BUTTERRESS DAM:
FORCES ACTING ON ARC DAM:

3. 2. GRAVITY DAM:
FORCES ACTING ON GRAVITY DAM:

4. 3. EMBANKMENT DAM:
FORCES ACTING ON EMBANKMENT DAM:

6. Dam Location
Issues
• Catchment
• Reservoir
• Slope Stability
• Foundation
Rock
• Silting

7. What Geological Input is required for the
engineering of a large dam?
• The stability and safety of the dam on its
foundations;
• The water-tightness of the reservoir
basin;
• The slope stability of the reservoir
perimeter
• The availability of suitable local
materials for its construction.

8. Preliminary Geological Investigations of
Dam Construction:
1.Topographical Studies.
2.Reservoir Location.
3.Petrology studies.
4.Mineralogy Studies
5.Structural Geological Studies.
6.Geological Factors Like Foundation
Conditions, Water tightness of reservoir,
availability of construction material.
7.General examination of rocks.
8.Indirect study methods for subsurface
investigations.
9.Preliminary Drill Hole Study.

9. Detailed Geological Investigations for Dams Site Selection:
• Study of Geological Toposheet.
• Study of the Area with reference to Geology.
• Study of Rock Types.
• Study of Structural Geology of the Area.
• History of the Area with reference to Rainfall Data.
• Study of Stream Channels with Diff. Order.
• Study of Seismic Data of the Area.
• Geomorphological Study.
• Preparation of Geological Map of the area in detail.
• Study of Core Drill Data and its interpretation.
• Detailed Engg. Geological Properties of the area.

10. Detailed Geological Investigations for Dams Site Selection:
• Study of Geological Toposheet.
• Study of the Area with reference to Geology.
• Study of Rock Types.
• Study of Structural Geology of the Area.
• History of the Area with reference to Rainfall Data.
• Study of Stream Channels with Diff. Order.
• Study of Seismic Data of the Area.
• Geomorphological Study.
• Preparation of Geological Map of the area in detail.
• Study of Core Drill Data and its interpretation.
• Detailed Engg. Geological Properties of the area.