What are the geological characteristics for investigation for selection of dam sites?

The following main factors are examined at the stage of selection of dam type: Topography and geological conditions of the proposed dam site, • Availability of suitable materials for the dam, • The feasibility of spillway construction, and • The need to be able to cope with conditions of extreme flood or earthquake.

What is dam site investigation?

‘L Soon after a dam site has been tentatively selected, the geologist makes. a preliminary investigation of the site. This consists of a field study and a review of available literature and maps relating to regional geol- ogy and physiography.

Why geological investigation is done at the reservoir site?

Among those studies is the geological investigations which should be carried out to deduce the geological conditions in the most relevant site, depth of the foundations and their types, cut-off depth, type of the available construction materials, and type of the expected geological hazards.

What is geological dam?

A damIs An Engineering Structure constructed across a valley or natural depression to create a water storage reservoir. Such reservoirs are required for three main purposes: (1) provision of a dependable water supply for domestic and/or irrigation use; (2) flood mitigation: and (3) generation of electric power.

What are the different types of geological investigation?

These are accomplished by following two broad methods: direct subsurface explorations and indirect subsurface explorations. The direct methods involve examination of rocks or materials of the underground by digging of drill holes, trial pits, adits, shafts, galleries and exploratory tunnels.

What are the geological conditions necessary for construction of dams?

It would be a narrow gorge or a small valley with enough catchments area available behind so that when a dam is placed there it would easily store a calculated volume of water in the reservoir created upstream.

How are sites for dams construction investigated?

A site investigation or soil survey is an essential part of the preliminary design work. Site investigation is performed in order to obtain information regarding the sequence of strata and the ground water level and also to collect samples for identification and testing.

What are the geological consideration when building a dam?

Factors Affecting Selection of Dam

  • Topography.
  • Geological and Foundation Conditions.
  • Availability of Materials.
  • Spillway Size and Location.
  • Earthquake Zone.
  • Height of Dam.

What are geophysical investigations?

35 C H A P T E R 4 Geophysical Investigations Introduction Geophysical investigations are used to estimate the physical properties of the subsurface by measuring, analyzing, and interpreting seismic, electrical, electromagnetic, gravitational, and magnetic fields measured at the ground surface or within boreholes.

What are methods of site investigation?

Boring, drilling, sampling, testing and nondestructive testing methods, as required, are employed to conduct site investigation. Sampling and testing are done remotely from the surface at some distance below the ground.

What are the geological considerations necessary in the selection of a construction site?

Among geological considerations, lithology, weathering, rock quality, rock structures, ground water, engineering properties of rock, rock cover, and pillar width are briefly discussed. Of the rock structures, foliations, bandings, faults, shears, shear zones and joints are examined from a ground behavior standpoint.

What are the geological problems associated with dam sites?

This chapter discusses the reservoir problems of slope instability, induced earthquake, excessive seepage, backwater flooding, and ice. SLOPE INSTABILITY Slides Of concern to dam safety is the possible movement of large masses of rock or soil into the reservoir.