Groundwater and Seepage

Milton E. Harr

• Publisher: Dover Publications
• Year: 2012
• eBook ISBN: 9780486145198
• Topic: Technology & Engineering
• Subtopic: Civil Engineering
• Index: Technology & Engineering

The movement of groundwater is a basic part of soil mechanics. It is an important part of almost every area of civil engineering, agronomy, geology, irrigation, and reclamation. Moreover, the logical structure of its theory appeals to engineering scientists and applied mathematicians.
This book aims primarily at providing the engineer with an organized and analytical approach to the solutions of seepage problems and an understanding of the design and analysis of earth structures that impound water. It can be used for advanced courses in civil, hydraulic, agricultural, and foundation engineering, and will prove useful to consulting engineers — or any public or private agency responsible for building or maintaining water storage or control systems.
Among the special features of this book are its coverage of previously unavailable Russian work in the field, an extensive appendix of concepts in advanced engineering mathematics needed to deal with physical flow systems, and numerous completely worked-out and solved examples coupled with over 200 problems of varying difficulty.

1

Fundamentals of Groundwater Flow

1-1. Scope and Aim of Subject

The aim of this work is primarily to present to the civil engineer the means of predicting the exigencies arising from the flow of groundwater. The specific problems which are to be dealt with can be divided into three parts:

1. Estimation of the quantity of seepage
2. Definition of the flow domain
3. Stability analysis

When writing on a subject as broad as groundwater and seepage, it is necessary to presume a minimum level of attainment on the part of the reader. Hence it will be assumed that the reader has a working knowledge of both the calculus and the rudiments of soil mechanics. For example, the problem of the stability of an earthen slope subject to seepage forces will be considered as solved once the upper flow line has been located and the pore pressures can be determined at all points within the flow domain. The actual mechanics of estimating the factor of safety of the slope will be left to the reader. Several texts on the subject of soil mechanics can be found in the references [142, 145].¹ However, such factors as the determination of the uplift pressures under structures, exit gradients, and all pertinent seepage quantities will be considered to be within the scope of this book.

Although the fundamentals of groundwater flow were established more than a century ago, it is only within recent years that the subject has met with scientific treatment. As a result of the trial-and-error history of groundwater-flow theory, its literature is replete with empirical relationships for which exact solutions can be and have been obtained. Advocates of the empirical approach have long reasoned that the heterogeneous nature of soils is such that rigorous analyses are not practical. This is not so; as will be seen, much of the subject lends itself readily to theoretical analysis.

Recent developments in the science of soil mechanics coupled with more precise methods of subsurface soil explorations have provided engineers with greater insight into the behavior of earth structures subject to groundwater flow. The mathematics of the theory of functions of complex variables, once the arid theory of imaginary numbers, now allows the engineer to solve problems of otherwise overpowering complexity.

The engineer can now formulate working solutions which not only reflect the interaction of the various flow factors but also allow him to obtain a measure of the uncertainties of his design.

1-2. Nature of Soil Body

In groundwater problems the soil body is considered to be a continuous medium of many interconnected openings which serve as the fluid carrier. The nature of the pore system within the soil can best be visualized by inference from the impermeable boundaries composing the pore skeleton. For simplicity it will be assumed that all soils can be divided into two fractions which will be referred to respectively as sand and clay...

Table of contents

• Title Page
• Copyright Page
• Dedication
• Preface
• Table of Contents
• List of Symbols
• 1 - Fundamentals of Groundwater Flow
• 2 - Application of the Dupuit Theory of Unconfined Flow
• 3 - Conformal Mapping by Elementary Functions
• 4 - Special Mapping Techniques
• 5 - Confined Flow
• 6 - Approximate Methods of Solution for Confined Flow Problems
• 7 - Unconfined Flow through Earth Structures on Homogeneous Foundations of Great Depth
• 8 - Unconfined Flow through Homogeneous Earth Structures of Finite Depth
• 9 - Seepage from Canals and Ditches
• 10 - Seepage toward Wells
• Appendix A
• Appendix B
• References
• Index
• A CATALOG OF SELECTED DOVER BOOKS IN ALL FIELDS OF INTEREST