ELECTRICAL ANALOGY AS APPLIED TO SUBSOIL FLOW STUDIES WITH SPECIAL REFERENCE TO THREE - DIMENSIONAL PROBLEMS

Abstract

The main purpose of this thesis is to present the electrical analogy investigations in the field of three• dimensional subsoil flow, with most of which the author has been associated or is currently associated. An attempt has b also been made to conci-sely present the available information concerning the history, theory, technique, applications and the recent developmentsof the various electrical anal' methods, viz, the tvo.dimensional, the sector, and the three. dimensional model methods* The several difficulties and limitations encountered in the various methods- have been discussed in the appropriate contexts. Apart from the applications to the subsoil flow problems which have been deAlt with in greater detail, some important hydraulic applications in.. volving surface flow phenomenon have also been discussed and typi. cal results presented. The review of research work already per. formed by the analogy methods has been given, and exhaustive t t typical results have been presented. Investigations in the field of subsoil flow under hydraulic structures on permeable foundations, with which the author (1) has been associated, have indicated that almost all such problems require a three-dimensional approach, except for a very limited number. The need for change of the usual two-dimensional concept in tackling such problems has, therefore, been indicated. Design considerations for the underground parts of hydraulic structures on permeable foundations may be improved by the use of the three.. dimensional technique in general. Particularly, for simple three-dimensional structures like syphons and falls, where boundary conditions are not too complicated, rational criteria for the design of foundations with respect to subsoil flow may be obtained by this technique. Such criteria for canal syphons have been presented typically. Problems of simulation of a tubewell, design of dewatering systems for deep foundations, and design of relief ,wells for hydraulic structures have been discussed and typical results presented. It has been concluded as a result of some basic stu-dies carried out recently, that the relative performance of a properly designed filter, and of properly designed fully penetra-ting relief wells, provided to relieve pressures at some inter-mediate reach in case of long escaping structures is almost the same. Certain problems for further research and experimentation have been indicated, and the desirability of observations for the study of model and prototype conformity has been stressed.