This book is included in the Self Reliance Water & Wells section.
Preface to the First Edition
The
great advantages to be derived from large storage
reservoirs, built for regulating the flow of a river, for irrigation
purposes, of for domestic water supply, have led within recent years to
the construction of a large number of such works in various parts of the
world. Where water having great depth is to be retained, it would be
extremely hazardous to rely on earthen dams, as numerous failures of
such works have been recorded and walls of masonry are, therefore,
employed.
The successful completion of the Furens Dam (164 feet high) in 1800 was
soon followed by that of many similar structures in France, Algiers, and
Italy. In the United States a concrete dam (170 feet high) is being
built near San Francisco; the Sodom Dam (70 feet high) has been
commenced on the East Branch of the Croton River; and the Quaker Bridge
Dam, which will surpass all existing dams in height, has been designed
to form an immense storage reservoir for the city of New York.
While the practical importance of the subject of masonry dams seems to
be steadily growing, the engineer who may be entrusted with the design
of such works will find the theoretical study of the best form of
profile for a masonry dam very disheartening. How widely the types
proposed by eminent engineers differ from each other is shown on plate
A, page 43.
The theory of masonry dams is based upon a few simple principles and
conditions; the mathematics, however, to which they give rise, when
applied to the design of an economic profile, are rather appalling.
Thus, if we follow the methods of the French engineers Sazilly and
Delocre, we have to solve lengthy equations, some of them of the sixth
degree. Moreover, there is always an uncertainty which equation is to be
used, and the only way of determining this is by trial. If we wish to
employ the method of Prof. Rankine, but change the data assumed by him,
we have to make trials with the subtangent of a logarithmic curve. In
contradistinction to these scientific methods, we find prominent
engineers recommending trial calculations a the best practical solution
to the problem.
The writer, when detailed by the Chief Engineer of the New Croton
Aqueduct to make calculations for the proposed Quaker Bridge Dam, the
height of which is to be 270 feet, after studying the existing methods
of designing profiles and finding them for various reasons inapplicable
to the case in view, finally arrived at the equations given in this
book. They are easy to solve, being, with the exception of one cubic
equation, of the first or second degree. The theoretical section of the
Quaker Bridge Dam was calculated by these equations, As the construction
of this gigantic dam, which is likely to be commenced soon, may lead
many persons to inquire how its profile was determined, the writer has
thought that a book giving the details of the method employed, and
information about masonry dams in general, might be of interest and
practical value to engineers. It is with this view that the present work
has been undertaken.
The text has been illustrated by numerous plates and tables, showing the
form and strength of the various profiles discussed. Data of forty-four
existing masonry dams have been collected in table XXIII.
The investigations given in Chapter IV., relating to the effect of the
weight of masonry upon the form of profile and the calculations for
inclined joints, were suggested in connection with the proposed Quaker
Bridge Dam by Mr. B.S. Church, Chief Engineer, and Mr. A. Fteley,
Consulting Engineer.
In the preparation of this book the writer has been assisted by some of
the engineers of the New Croton Aqueduct, who have become interested in
these studies, and he wishes to express herewith his thanks to Mr. H.C.
Alden and Mr. M.A. Viele, who have helped him to calculate the tables,
and to Mr. G. Bonanno and Mr. I.A. Shaler, who have rendered valuable
aid in making the drawings and in collecting information about existing
dams.
E.W., Jr.
New York, April, 1888
Preface to the Sixth Edition
The
first edition of this book appeared in 1888 as a
treatise on "Design and Construction of Masonry Dams." It gave the
formulae usually adopted for calculating the distribution of pressure in
a masonry dam, and the equations devised by the author for determining
the minimum profile for such a structure.
Since the first edition was published, a number of engineers and
mathematicians have tried to evolve formulae that would give, as nearly
as possible, the actual distribution of stresses in a masonry dam, based
upon the results obtained by experiments on models of dams, made of
elastic substances. The reader interested in these investigations will
find them mentioned in the bibliography in the Appendix.
While these studies are in the right direction and will, doubtless,
advance our knowledge of the stresses that occur in masonry dams, we
must bear in mind the fact, so clearly pointed out by Sir Benjamin Baker
(Proc. Inst. C.E., Vol. 162, p. 120), that in all mathematical
investigations the masonry in a dam is assumed to be perfectly elastic
and at a uniform temperature, while these conditions do not exist in a
real masonry dam.
Many masonry dams have been built according to the simple principles of
design explained in the first edition of this book, and prove that,
while these principles may not be absolutely true, they lead to safe
results. An engineer would hardly dare to reduce the profile of a dam to
a less area than that given in plate XIV of this book and, if he did,
his dam would not have sufficient strength against shearing and sliding.
In the present state of our knowledge, we may, therefore, continue to
design masonry dams according to the simple methods explained in the
first edition of this book.
In preparing the fourth edition in 1899, the scope of the book was
enlarged so as to include dams of masonry, earth, rock-fill and timber,
and, also, the principle types of movable dams.
In the fifth edition, which appeared in 1907, descriptions of steel and
reinforced steel dams, Stoney Sluice Gates and Rolling Dams were added.
Sooner than was expected, a new edition has become necessary. In this
Edition two new chapters have been added to the book, viz., one on
Overflow Weirs, and the other on Coffer Dams. The theory of masonry dams
given in the first editions of this book is applicable only to reservoir
walls over which water is not supposed to pass. The design of overflow
weirs must be based upon other principles, which have been explained in
the present edition. If this difference is not observed, failure is
likely to result. The chapter on Overflow Weirs includes a discussion of
the design of weirs built on sand and gravel foundations, such as the
Laguna Dam in the United States, and many weirs in India and Egypt.
Coffer-dams are often required in building dams and weirs. As very
little has been written about this subject, the author has devoted a
chapter in this edition to Coffer-dams, giving the different types of
such structures and descriptions of coffer-dams actually built,
including the one at Hauser Lake, which was recently constructed in 70
feet of water by means of pneumatic caissons.
The descriptions of important dams of various kinds have been brought up
to date. In describing the dams that have been built during the past
twenty-five years to form additional storage reservoirs for the City of
New York, the author is able to speak from his own observation, and he
has given in these cases many practical details, including some cost
data of the New Croton Dam, which are not only of interest to engineers,
but also to contractors.
In giving descriptions of the many dams that have been built of late in
different parts of the world, the author has not only drawn his
information from the technical press and the transactions of engineering
societies, giving in all cases proper credit, but he has obtained his
data, wherever it has been feasible, directly from the engineers in
charge of these works.
The author wishes to acknowledge here his indebtness to the many
engineers who have assisted him in this manner, and especially to Col.
Geo. W. Geothals, Chairman and Chief Engineer of the Isthmian
Commission, who sent the author a description of the Gatun Dam with
plans and photographs.
From a book containing in 1888 only 106 pages of text and 59 plates,
treating of masonry dams, this work ha grown so as to include in the
present edition 529 pages and 157 plates, covering the whole subject of
the design and construction of dams. In order that no kind of dam should
be omitted short accounts of beaver dams, trembling dams, and tinker
dams are given in the appendix.
E.W.
New York, June 1, 1911
CONTENTS
Part I. - Design & Construction of Masonry Dams
Chapter I. Introduction
Chapter II. Distribution of Pressure in a Wall of Masonry
Chapter III. Theoretical Profiles
Chapter IV. Various Applications of Equations (1) to (14)
Chapter V. Practical Profiles
Chapter VI. Construction
Chapter VII. Spanish Dams
Chapter VII. French Dams
Chapter VIII. Dams in Various Parts of Europe
Chapter IX. Dams in Algiers
Chapter X. Dams in Egypt
Chapter XI. Dams in Asia and Australia
Chapter XII. American Dams
Chapter XIII. Reinforced Concrete Dams
Part II. - Earthen, Rock-Fill, Timber & Steel Dams
Chapter I. Earthen Dams
Chapter II. Dams made by the Hydraulic Process
Chapter III. Rock-Fill Dams
Chapter IV. Timber Dams
Chapter V. Steel Dams
Part III. - Moveable Dams, Coffer-Dams, & Overflow Weirs
Chapter I. Frame Dams
Chapter II. Shatter Dams
Chapter III. Dams with Bear-Trap Gates
Chapter IV. Stoney Roller Sluice-Gates, Rolling Dams, Butterfly Dams,
Etc.
Chapter V. Coffer-Dams
Chapter VI. Overflow Weirs
Part IV. - Recent Dams
Appendix.
Specifications for the New Croton Dam
Notes on A, B, and C
Tables I to XXV
Calculation of Theoretical Profile No. 6
Partial Failures of the Minnesota Dam
Slide in the Necaxa Dam No. 2
Partial Failure of the Zuni Dam
Beaver Dams
Trembling Dams
Tinker Dams
Cost Data of the New Croton Dam
Bibliography
Index
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