Date on Master's Thesis/Doctoral Dissertation

12-1949

Document Type

Master's Thesis

Degree Name

M. Eng.

Department (Legacy)

Department of Civil Engineering

Committee Chair

Wendt, W. B.

Committee Co-Chair (if applicable)

Northrop, M. G.

Committee Member

Northrop, M. G.

Committee Member

McIntosh, W. R.

Committee Member

Williams, G. C.

Committee Member

Ernst, R. C.

Subject

Earth dams--Design and construction

Abstract

This thesis deals with the design and construction of rolled-fill earth dams with the standard methods of practice, taking the Hirakud Dam as the basis. The field operations of the investigation to obtain observational information and to secure samples for the laboratory testing include observation of rain gauge and river gauge readings, taking river water samples, digging test pits, drilling grout holes, opening drifts, digging borrow pits and conducting detailed topographical surveys. Laboratory tests are conducted on the samples and the results are plotted in graphs. Rainfall and run-off statistics are plotted in graphs. Observational information of geology is plotted in log sheets and the field data of survey works is made use of for the preparation of the topographical maps.

From the results of the investigation it is found that the Hirakud Dam has a firm foundation and there is sufficient quantity of material for the embankment at site. The annual rainfall is 47.49 inches yielding a run-off of 50 million sore feet over a catchment area of 32,200 square miles. The stability of the embankment is computed by the slip circle method and the seepage water from the flow net method.

The dam is designed for 100 years with a reservoir capacity of 5.98 million acre feet at the maximum water level elevation 625 feet, the bed level being elevation 500 feet. The dead storage is 2.24 million acre feet corresponding to elevation 590 feet, and the maximum submerged area corresponding elevation 625 feet is 150,380 acres. The minimum factor of safety for the upstream slope is 1.68 and that for the downstream slope is 1.19. The seepage water is 0.264 cubic feet per lineal foot per year.

The dam is to be constructed as per the design and the specifications. The compaction is attained by the mechanical effort at the optimum moisture content. The mechanical effort is influenced by the type of roller, its weight and the number of passes. Field control is affected by vigilant supervision, needle penetration, ring test and sand test. The construction is to be carried out according to a plan of seven stages.

A comparison and contrast is drawn between the U.S.A. and India to bring out the inherent difficulties of construction operations of large dams in India. Importance is given to the sequence of the subject matter since no text book gives all the relevant portions as used in practice. Reference is given to the text books from which the formulas are taken so that a student who is interested in theory, derivation and explanation of the formulas may study the available literature.

The procedures employed and the conclusions drawn are based on the experience, observation and the research study of the author both in India and the United States of America.

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