Microcomputer Software for Civil Engineers

372 Pages·1986·23.198 MB·English

by  Howard Falk (auth.)

MICROCOMPUTER
SOFTWARE
FOR
CIVIL ENGINEERS
MICROCOMPUTER
SOFTWARE
FOR
CIVIL ENGINEERS
Howard Falk
rniTi5lVAN NOSTRAND REINHOLD COMPANY
~ _______ New York
Copyright © 1986 by Van Nostrand Reinhold Company Inc.
Softcover reprint of the hardcover 1st edition 1986
Library of Congress Catalog Card Number: 86-5614
ISBN-13: 978-1-4684-6586-0 e-ISBN-13: 978-1-4684-6584-6
DOl: 10.1007/978-1-4684-6584-6
All rights reserved. No part of this work covered by the copyright hereon may
be reproduced or used in any form or by any means-graphic, electronic, or
mechanical, including photocopying, recording, taping, or information storage
and retrieval systems-without permission of the publisher.
Published by Van Nostrand Reinhold Company Inc.
115 Fifth Avenue
New York, New York 10003
Van Nostrand Reinhold Company Limited
Molly Millars Lane
Wokingham, Berkshire, RGll 2PY, England
Van Nostrand Reinhold
480 Latrobe Street
Melbourne, Victoria 3000, Australia
Macmillan of Canada
Division of Gage Publishing Limited
164 Commander Boulevard
Agincourt, Ontario MIS 3C7, Canada
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
Library of Congress Cataloging-in. Publication Data
Falk, Howard, 1927-
Microcomputer software for civil engineers.
Includes index.
1. Civil engineering-Data processing. 2. Micro
computers. 1. Title.
TA345.F35 1986 624' .028'553 86-5614
ISBN-13: 978-1-4684-6586-0
Preface
This is a book about software packages for use by civil engineers. It is
written for engineers who need software that can do the job without re
quiring that they become computer experts or programmers.
The purpose of this book is to present a broad picture of the personal
computer packages now available for use by civil engineers. Each chapter
is devoted to an area, such as structures, surveying, hydrology, drafting,
or equation-solving, in which a number of software packages are presently
offered for use with personal computers. The chapter introductions explain
what kinds of design or analysis or other tasks these packages perform,
outlining the available choices, and comparing the capabilities of the var
ious packages.
Detailed reviews of individual packages follow. The emphasis here is on
what the user must know and do to employ the capabilities of the package.
Going beyond general description, these reviews also explain what the pack
ages actually will and will not do. Although many packages are covered,
there is no attempt here at completeness. In every category covered in the
book, many more packages exist than those that have been reviewed. In
the fast-moving field of engineering software, many new packages are cur
rently being written and marketed.
A new style of computing
Personal computers have become widely, perhaps universally, accepted
as everyday tools for business applications. An essential prerequisite for
this acceptance has been the availability of software packages designed for
easy use by business people who have little or no background in computing.
It is ironic that although engineers were using computers long before most
business people dared approach a keyboard, personal computer software
packages for engineering applications have been slow to develop.
When minicomputers and large, mainframe computers are used to solve
engineering problems, the assumption has generally been that the user must
know and use a computer language, such as FORTRAN or BASIC. And
it has been assumed that operation of the computer system must be ar-
v
vi PREFACE
ranged for maximum effective use of computer resources, rather than for
the convenience of engineering users.
The basic premises of personal computing are quite different. Users have
exclusive access to their own computers, so the way they employ computing
resources is shaped entirely by their own needs and whims. Although per
sonal computer software can be created by the user, the software is usually
purchased in the form of a package, shaped to perform the tasks the user
wants the computer to do.
In this world of personal computing, the extent to which computers can
be useful for performing engineering tasks depends largely on what kinds
of engineering software packages are available. If there is a package for the
structural design or surveying calculation or drafting task that needs to be
done, then the personal computer can be used. If no such package exists,
the engineer will probably turn to other means of doing the work.
A critical approach
The approach throughout this book is a critical one. Each application
area and each software package is examined from the point of view of en
gineering users, specifically those users who may run a computer only oc
casionally, when particular problems have to be solved.
Toward the use of formal computer languages, the approach in this book
is a skeptical one. It is useful for engineers to know how to program, if for
no other reason than to gain a feeling of mastery over computers. But civil
engineers are not, and probably should not be, programmers. Except for
those few who decide to take up programming as their vocation, engineers
use computers as they use any other tools-to help them carry out engi
neering tasks.
Some engineers spend much of their time at computer keyboards, doing
analyses, design, planning, and similar tasks. For these users, learning a
special computer language, such as COGO, or the special-purpose lan
guages used by some finite element analysis, statistical, drafting, and other
packages, can bring advantages both in speed and flexibility of problem
solving.
For the most part, what engineers need are software packages that will
allow them to continue to think in strictly engineering terms while getting
the benefit of computing power. Writing programs that can offer this kind
of capability is not an easy task, but it is what the field of programming
for engineering applications is all about. It is the task that the vendors of
engineering packages for personal computers have taken on. This book in
cludes many examples of excellent packages that meet these requirements.
Where packages fall short, they have been commented on in a critical man
ner.
HOWARD FALK
Contents
Preface / v
1. HVA C Design Packages / 1
2. Concrete Structure Design / 23
3. Structural Design and Analysis / 38
4. Hydrology Design Packages / 68
5. Surveying and Cartography Packages / 87
6. Finite Element Analysis Packages / 107
7. Simulation Packages For Personal Computers / 132
8. Drafting Packages / 145
9. Symbol/Object Manipulation Graphics Packages / 173
10. Curve and Chart Graphics Packages / 188
11. Cost Estimation and Tracking Packages / 207
12. Project Management Packages / 226
13. Equation-solving Packages / 261
14. Linear Programming Packages / 285
15. Comprehensive Statistical Packages / 312
16. Instrumentation Packages / 346
Index / 363
vii
MICROCOMPUTER
SOFTWARE
FOR
CIVIL ENGINEERS
Chapter 1
HV AC Design Packages
Calculation of building energy loads is the main task taken on by many
personal computer HVA C packages. Although the computers used are
small, the buildings that are modeled by these packages may be substantial
in size. For example, the C-HV AC package can handle commercial build
ings with up to 1000 rooms and as many as 100 heating-cooling systems.
The R-HV AC residential package will also handle up to 1000 rooms. How
ever some other packages are limited to only a few zones and rooms, so
prospective users should take care to check the capacity of these packages
as well as the types of answers they can provide.
California builders have the problem of demonstrating compliance with
that state's Residential Building Energy Standards. These standards are strict
compared with those of other states, but are indicative of a national trend
toward designs that minimize energy use in all buildings, including single
family residences. Compliance of a building design with such standards can
be demonstrated by using an approved calculation method such as that pro
vided by the Micropas package.
Other HVAC packages, like REENERGY, are strictly preliminary design
tools, intended for assessing the magnitude of estimated energy consumed
for specific building components and for stimulating energy-efficient design
concepts, rather than demonstrating energy code compliance.
Some HVAC packages, like DUCT 1-2-3, calculate size, velocity, pres
sure, and other design parameters for ducts used in air conditioning, ven
tilation, and exhaust systems.
Item and full-screen input editing
With HV AC packages, the overwhelming task facing the user is to get
the required information into the computer. The number of different fac
tors entering into a calculation of energy loads for a building can run into
the hundreds. The practical usefulness of these packages must therefore be
2 MICROCOMPUTER SOFTWARE FOR CIVIL ENGINEERS
judged by the extent to which they can aid users in carrying through their
input tasks.
These packages generally take advantage of the interactive, back-and
forth dialogue between user and display that personal computers typically
use. Thus with the C-HVAC package, input from the keyboard is on an
item-by-item question-and-answer basis. For the roof data, the package asks
for the ASHRAE roof number, the user fills that in, then is asked for a U
factor, and so the dialog proceeds. In this package, the allowed answers
are fixed in format. To indicate how many characters or digits are allowed,
the package displays a string of dots above the answer space. When entries
are to be changed, the previous value used for that item is displayed within
the question that calls for a new value.
Full-screen editing offers an alternative and usually a more powerful,
method of interactive data entry. For example, in the R-HVAC package,
positions for many input items are provided on a single display. The user
moves from one item to another on the screen, entering new data or revising
existing entries. When finished, the user can visually review what has been
entered, making corrections as needed before the entire screen is stored and
committed as input for calculations.
In the DUCT 1-2-3 package, the user is completely free to move the dis
play cursor to any location on the screen and edit the material displayed
there. This is an ideal procedure when a few changes are necessary on an
otherwise-acceptable screenful of information.
Working from existing data
One of the best ways to speed up the laborious input process is to work
from existing, similar sets of data, replacing only those items that are unique
to the current design problem. Thus the SYRSOL package retains input
data in disk-stored files. When the data for a current analysis are similar
to those of a previous one, the user can call up the previously entered input
data file and make changes in selected items only. Most HVAC packages
provide some sort of similar replacement feature.
Some packages come with typical or sample values already set, and the
user then accepts or alters those values. For example, the HEATCOOL
package comes with input parameters set for an office building in Sacra
mento, California. The parameters are displayed in three tables, each of
which can be accepted as is or changed. When the user reviews a table and
calls for changes, the items in that table are presented for revision one at
a time, and the user can call for a printout of that table when the changes
are completed.
The degree of freedom in editing existing data offered by different pack-
HVAC DESIGN PACKAGES 3
ages varies considerably. With the Micropas package, although arrays of
screen-displayed data can be edited, the package does not provide full-screen
editing in the sense that a cursor can be moved to a displayed item to guide
changes. Instead the user must enter the number of changes to be made,
then the column and row numbers of the items to be changed. The actual
changes are then made as if isolated individual items were being altered.
The C-HVA C package allows users to skip from one input prompting
question to another by pressing the Return key. At many of the questions
the option of bypassing or "zapping" the remainder of the input process
can be exercised simply by pressing the Z key.
Data replication is another technique that can be of great assistance in
getting the needed data into the computer. In this regard C-HV AC allows
up to 100 heating-cooling systems to be described. As these will probably
not be individually unique, the package includes the ability to repeat the
same description parameters for any desired number of air systems. Since
zone data may likewise be similar or identical for many zones, the package
also allows data from one zone to be copied into a new one. The user then
has only to revise those items that differ between the two zones.
Design flexibility
In HV AC design, as in many other areas of engineering work, it is de
sirable to compare different design alternatives. With their ability to rapidly
find answers that might otherwise take a long time to hand calculate, com
puters offer the ability to explore more and varied alternatives.
For example, "what if" analyses are not an accustomed part of residen
tial design calculations, but a package like Micropas allows residential
building designers to change their inputs and then repeat their simulation
runs quite easily.
The C-HVAC package makes it easy for the user to "turn on" or "turn
off" any of the air systems in a commercial building being simulated by
that package. This feature is very useful when variations in number of
building zones and associated air systems are being considered.
The HEATCOOL package provides for room-by-room trial and varia
tion. Input data are entered separately for each room in the building. As
the data for a given room are completed, the package calculates energy load
totals for that room and displays the results. At this point the user can
review these results and return to the input for that room to make any
desired changes.
Although they give only approximate answers, packages like SEA are
well equipped to aid in exploring design alternatives. With its relatively sim
ple calculation methods, SEA can be used to quickly and effectively com-