Introduction to Design for Civil Engineers

Introduction to Design for Civil Engineers


Our aim in writing this book is to bring out the broad issues affecting all design.
We have not attempted to provide prescriptions, formulae or recipes to solve
particular problems. These can all be found in codes, manuals and other books.
We have instead concentrated on the factors affecting design and the process
undertaken. Engineering education tends to be a compartmentalised learning of
different techniques. The main missing link is the appreciation of the purpose
behind these techniques, and the context of their application. We have tried to
illustrate the all-pervasive nature of design.
The book is particularly aimed at young engineers and undergraduates. We
hope that we have kindled their curiosity, so that students feel that their studies
are purposeful. We believe that this in turn will allow the students to derive more
from their curriculum. It is hoped that the book will enable them to appreciate the
bigger picture, and how many of the skills they had acquired in a disparate fashion
can be brought to play in a constructive manner.
The book has been a pleasure to write, and our hope is that it contributes to the
understanding of the creative activity that is design.


major objective of design is to avoid failures; most of this book is indirectly concerned
with introducing the methods used for ensuring that failures do not occur.
There are, in fact, a number of different types of failure and, before entering into
the study of these methods, it is essential to understand the differences between
them.
We shall start by considering failure in its broadest sense and illustrate this by a
story related to one of the authors by his father, who was for many years concerned
with construction in various parts of the world. The supply of water to an industrial
plant for which his company acted as consultant required the construction of
a water tower in order to provide sufficient water pressure at the plant. The tower
had to be fairly tall and was to be built of reinforced concrete. A small local contractor
was given the job of building the tower. He had no mechanical equipment
and the concrete was all mixed by hand and taken to the tower in baskets carried
on the heads of women.

LINK

Design of Cantilever Slab Spreadsheet

Design of Cantilever Slab Spreadsheet



Cantilever slabs are a typical one way slabs. They are projections from wall face of lintel beams or floor slabs. Even while designing they are considered as one-slabs with cantilever fixed or continuous at supports. The trial depth is selected based on span/depth ratio of 7, as in IS:456. The reinforcement provided at the tension face should be checked for anchorage length near supports. The thickness of such slabs is varied from max. at the fixed end to the min. of 100 to 150 mm at the free end. Distribution steel should be provided at the transverse direction. Proper selection of depth and detailing of reinforcements will safeguard against excessive deflections and cracking of the cantilever slabs. Also, cantilever structural elements should be checked for safety against overturning.



LINK

Practice Problems for the Civil Engineering PE Exam

Practice Problems for the Civil Engineering PE Exam


Practice Problems for the Civil Engineering PE Exam contains 755 problems designed to help you identify important civil engineering topics and apply your knowledge to a variety of problems. Short, six-minute, multiple-choice problems demonstrate the format of the NCEES Civil PE exam and help you concentrate on a single subject. More complex problems combine several concepts, illustrate efficient and accurate solving methods, and familiarize you with the codes, standards, and references you’ll need for the exam. Solutions are clear, complete, and easy to follow. U.S. customary and SI units are equally supported, and units are meticulously identified and rigorously carried through all calculations. Where multiple methodologies (e.g., ASD and LRFD) are permitted by the exam, both solutions are presented in this book. Frequent references back to the Civil Engineering Reference Manual and the original codes and standards direct you to support material when you need it.


Prepare for the Civil PE Exam by Solving Problems—The More Problems, the Better

Over 750 practice problems covering the topics, codes, and standards on the Civil PE exam
More than 350 exam-like, multiple-choice practice problems
Over 360 scenario-based and short answer problems
Complete step-by-step solutions
SI and U.S. Customary units used throughout
Chapters that correspond to those in the Civil Engineering Reference Manual
More than 130 tables and 530 figures
What’s New in the 13th Edition

Over 370 revised and/or updated practice problems including structural, transportation, and construction practice problems that reflect NCEES-adopted codes and standards
More than 65 new practice problems
Use of consistent nomenclature between chapters
Over 80 revised and/or new figures
More than 15 revised and/or new tables

LINK

Pile Group Analysis Spreadsheet

Pile Group Analysis Spreadsheet



Pile group analysis spreadsheet program written in MS-Excel for the purpose of analysis of pile groups with rigid caps using the "elastic method". Specifically, the properties of the pile group are calculated, and then based upon the applied vertical and horizontal loadings, the vertical and horizontal pile reactions are calculated. There is also a worksheet to check beam and punching shear in the pile cap for a single corner pile, for the purpose of estimating the required pile cap thickness and subsequent pile cap weight.


LINK

Asphalt Materials and Mix Design Manual

Asphalt Materials and Mix Design Manual


The purpose of the Manual for Asphalt Materials and Mix Design
(hereafter referred to as The MANUAL) is to familiarize students
with the technology of asphalt in its several forms namely
asphalt cement, cutback asphalt, and asphalt emulsions. The
laboratory work is designed to develop an understanding of
asphalt properties, characteristics, testing procedures, and
specifications.
For engineering purposes three properties of asphalt are
paramount: consistency (usually referred to as viscosity),
purity, and safety. Before asphalt cement can be used for
construction purposes it must be liquefied. This implies heating.
Asphalt cement must be liquefied before it can be pumped through
pipes, mixed with aggregates to make asphalt concrete, or sprayed
through nozzles. Once the heat is dissipated, the asphalt cement
reverts to its amorphous, semi-solid state. There are other ways
to liquefy asphalt. Selected petroleum based solvents can
dissolve the asphalt cement to create a family of materials known
as cutback asphalts. Another method is to combine asphalt cement
with water in the presence of a catalyst to form various kinds of
asphalt emulsions.


The MANUAL consists of the following:
1. 3 5 of the frequently used ASTM tests in Asphalt
Binder and Mix Design.
2. Sample computations and easy to use Data Sheets, most of
which have been developed specifically for The MANUAL.
3. An up-to-date overview of Asphalt Technology including
sources, historical development, and classifications of
asphalt products.
4. Easy to understand explanations for Voids Mineral
Aggregate, Absorbed Asphalt, Effective Asphalt Content,
Percent Air Voids, and Percent of Voids filled with Asphalt.
5. A stand-alone asphalt manual, written specifically for
university laboratory instruction, yet applicable for a
commercial testing laboratory. Rarely will other reference
materials need to be consulted.
6. Dimensions in both the SI and the U.S. Standard systems
of measurement.
7. An Appendix with conversion factors, rules of safety and
procedures, overview of SHRP SUPERPAVE, explanation of
asphalt emulsions, and additional data sheets on
single-sided pages.

LINK

Composite Beam Design with Verco Floor Deck Spreadsheet

Composite Beam Design with Verco Floor Deck Spreadsheet



Composite Beam Design with Verco Floor Deck Spreadsheet provides the analysis and design of composite beams. The input studs spacing must be based on actual deck ribs spacing for perpendicular to beam.


LINK

Design and Construction of Concrete Floors

Design and Construction of Concrete Floors


Concrete floors lie all around us. Every building has a floor, and in most
industrial and commercial buildings that floor is made of concrete. Many
houses also have concrete floors.
Regrettably, many of those floors fail to do their job. Floors are responsible
for more user complaints than any other building element except roofs.
Good floors exist, but they seldom appear by accident. They require
good design, which requires a philosophy, by which I mean a coherent,
integrated way of looking at a subject. Too often, a floor design is a jumble:
a list of national standards, some clauses borrowed from the last project
manual and a few heavily promoted, proprietary products. That is no way
to do the job.


This chapter sets out the philosophy on which the rest of the book is
based. The essential ideas are these:
● A floor has a dual role. It is part of a building, but it is also part of the
building user’s equipment.
● A floor must be designed around the user’s needs and wishes.
● Floor designers should not focus narrowly on structural strength, but
must consider other important properties of the floor.
● Good design requires equal attention to five factors: floor usage; structural
strength; properties of the concrete itself; cracks and joints; and
properties of the floor surface.
● Performance specifications usually work better than method specifications.
● Single-course floors usually work better than double-course floors.
● National standards should be used with care.
● Lessons from roadbuilding should be applied to floor construction.
● Remedies for bad work should be specified before the bad work occurs.

LINK

Reinforced Concrete Design Eighth Edition

Reinforced Concrete Design Eighth Edition


The primary objective of Reinforced Concrete Design,
eighth edition, remains the same as that of the previous
editions: to provide a basic understanding of
the strength and behavior of reinforced concrete members
and simple reinforced concrete
structural systems.
With relevant reinforced concrete research and literature
continuing to become available at a rapid rate, it is the
intent of this book to translate this vast amount of information
and data into an integrated source that reflects the latest
information available. It is not intended to be a comprehensive
theoretical
treatise of the subject, because it is believed
that such a document could easily obscure the fundamentals
emphasized in engineering technology and applied engineering
programs. In addition, it is believed that adequate
comprehensive books on reinforced concrete design do exist
for those who seek the theoretical background, the research
studies, and more rigorous applications.
This eighth edition has been prepared


Concrete consists primarily of a mixture of cement and fine
and coarse aggregates (sand, gravel, crushed rock, and/or
other materials) to which water has been added as a necessary
ingredient for the chemical reaction of curing. The bulk
of the mixture consists of the fine and coarse aggregates. The
resulting concrete strength and durability are a function of
the proportions of the mix as well as other factors, such as
the concrete placing, finishing, and curing history.
The compressive strength of concrete is relatively high.
Yet it is a relatively brittle material, the tensile strength of
which is small compared with its compressive strength.
Hence steel reinforcing rods (which have high tensile and
compressive strength) are used in combination with the
concrete; the steel will resist the tension and the concrete the
compression. Reinforced concrete is the result of this combination
of steel and concrete. In many instances, steel and
concrete are positioned in members so that they both resist
compression.

LINK

BOUNDARY ELEMENTS Theory and Applications

BOUNDARY ELEMENTS Theory and Applications


The last three decades have been marked by the evolution of electronic computers
and an enormous and wide-spread availability of computational power. This has

boosted the development of computational methods and their application in engi-
neering and in the analysis and design of structures, which extend from bridges to

aircrafts and from machine elements to tunnels and the human body. New scientific

subfields were generated in all engineering disciplines being described as "Compu-
tational", e.g. Computational Mechanics, Computational Fluid Mechanics, Com-
putational Structural Analysis, Computational Structural Dynamics etc. The Finite

Element Method (FEM) and the Boundary Element Method (BEM) are the most
popular of the computational methods. While the FEM has been long established
and is most well known in the engineering community, the BEM appeared later
offering new computational capabilities with its effectiveness, accuracy and low
computational cost.


Although the BEM is taught as a regular course at an ever increasing number of
universities, there is a noticeable lack of a textbook which could help students as
well as professional engineers to understand the method, the underlying theory and
its application to engineering problems. An essential reason is that BEM courses

are taught mainly as advanced graduate courses, and therefore much of the under-
lying fundamental knowledge of mathematics and mechanics is not covered in the

respective undergraduate courses. Thus, the existing books on BEM are addressed
rather to academia and researchers who, somehow, have already been exposed to
the BEM than to students following a BEM course for the first time and engineers
who are using boundary element software in industry.

LINK

Composite Structures of Steel and Concrete

Composite Structures of Steel and Concrete


This volume provides an introduction to the theory and design of compos-
ite structures of steel and concrete. Readers are assumed to be familiar

with the elastic and plastic theories for the analysis for bending and shear
of cross-sections of beams and columns of a single material, such as
structural steel, and to have some knowledge of reinforced concrete. No
previous knowledge is assumed of the concept of shear connection within
a member composed of concrete and structural steel, nor of the use of
profiled steel sheeting in composite slabs. Shear connection is covered in
depth in Chapter 2 and Appendix A, and the principal types of composite
member in Chapters 3, 4 and 5.


All material of a fundamental nature that is applicable to structures for
both buildings and bridges is included, plus more detailed information
and a fully worked example relating to buildings. The design methods are
illustrated by calculations. For this purpose a single problem, or variations
of it, has been used throughout the volume. The reader will find that the

dimensions for this structure, its loadings, and the strengths of the materi-
als soon remain in the memory. The design is not optimal, because one

object here has been to encounter a wide range of design problems, whereas
in practice one seeks to avoid them.
This volume is intended for undergraduate and graduate students, for
university teachers, and for engineers in professional practice who seek
familiarity with composite structures. Most readers will seek to develop the
skills needed both to design new structures and to predict the behaviour of
existing ones.

LINK

Project Analysis for Business Consulting Firms Company Confidential Template

Project Analysis for Business Consulting Firms Company Confidential Template



Project Analysis for Business Consulting Firms Company Confidential Leads efforts for developers or testing professionals to enhance and create products Full lifecycle project management- including all core aspects required to successfully plan, forecast, manage and execute, reporting to key stakeholders as needed Lead enhancement projects of various levels of complexity in a project manager role, including creation of project schedule and risk management tasks


LINK

Design of Precast Prestressed Composite Beams Excel Sheet

Design of Precast Prestressed Composite Beams Excel Sheet



The precast prestressed concrete units are erected first and can be used to support the formwork needed for the cast in situ slab without additional scaffolding (or shoring). In addition to its contribution to the strength and stiffness of the composite member, the cast in situ slab provides an effective means to distribute loads in the lateral direction. The cast in situ slab can be poured continuously over the supports of precast units placed in series, thus providing continuity to a simple span system.Pre-tensioning in plant is more cost-effective than post-tensioning on site. Because the precast 4 prestressed concrete element is factory-produced and contains the bulk of reinforcement, rigorous quality control and higher mechanical properties can be achieved at relatively low cost. The cast in situ concrete slab does not need to have high mechanical properties and thus is suitable to field conditions.


LINK

BIM Handbook A Guide to Building Information Modeling

BIM Handbook A Guide to Building Information Modeling


The BIM Handbook is addressed to building developers, owners, managers,

and inspectors; to architects, engineers of all disciplines, construction contrac-
tors, and fabricators; and to students of architecture, civil engineering, and

building construction. It reviews Building Information Modeling and its related
technologies, its potential benefi ts, its costs and needed infrastructure. It also
discusses the present and future infl uences of BIM on regulatory agencies; legal
practice associated with the building industry; and manufacturers of building
products—it is directed at readers in these areas. A rich set of BIM case studies
are presented and various BIM tools and technologies are described. Current
and future industry and societal impacts are also explored.


BIM is developing rapidly, and it is diffi cult to keep up with the advances in

both technology and practice. Integrated Project Delivery (IPD) is a collabo-
rative contracting paradigm that has been developed and adopted within the

three years since we completed the fi rst edition. BIM tools are increasingly used
to support sustainable design, construction, and operation. There has been
increasing support by BIM for lean design and construction methods which
are highlighted throughout the book. Some innovations we predicted would
become commercial by 2012, such as tracking of building components using
BIM and radio-frequency ID tagging, have already been used in practice.
This edition not only addresses these themes and updates the material related
to the BIM applications; it also introduces sections on new technologies, such as
laser scanning and BIM servers. It also includes six new case studies.

LINK

RC Shear Wall Analysis and Design Excel sheet

RC Shear Wall Analysis and Design Excel sheet 



RC shear wall analysis and design excel sheet easy to use yet innovative construction spreadsheet is used to make the design of shear walls subject to wind and dead load combination. This shear wall design spreadsheet is very useful verifying constancy toward reinforced concrete structure.

 It takes huge time while measuring & then remeasuring wall stiffnesses, direct and torsional rotation component of force to then estimate reinforcement and concrete stresses for a single wall successively. This shear wall design spreadsheet can significantly decrease your design time.

 Presently, the sheet does not support the earlier version of excel like Excel 2003 and so on as these do not make out iferror function.

 This estimating spreadsheet contains the following exclusive characteristics :-

 An apparent and simplified output (all on a single page);
Design Reinforced Concrete walls subject to dead and wind load combination;
Enter highest and least safety factors for Dead Load toward most troublesome load combination;
Identify superstructure and substructure height. Wind load can be assigned to above ground part of structure;
 Identify length of wall ends obstructing tension;
Designs horizontal and vertical reinforcement;
Verify least/highest acceptable reinforcement areas;
'Live' wall diagram;
Design is created on the basis of British Standard


LINK

Guide to Concrete Repair

Guide to Concrete Repair


This guide contains the expertise of numerous individuals who have directly assisted the author on many concrete repair projects or freely shared their concrete repair knowledge whenever requested. Their substantial contributions to the preparation of this guide are acknowledged and appreciated. Some of the material in this guide originated in the various editions of Reclamation’s Concrete Manual. The author edited, revised, or updated this information for inclusion herein.


concrete is a very durable construction material and, if properly proportioned and placed, will give very long service under normal conditions. Many Reclamation concrete structures, however, were constructed using early concrete technology, and they have already provided well over 50 years of service under harsh conditions. Such concrete must be inspected regularly to ensure that it is receiving the maintenance necessary to retain serviceability. Managers and foremen of operation and maintenance crews must understand that, with respect to concrete, there is no such thing as economical deferred maintenance. Failure to promptly provide the proper necessary maintenance will simply result in very expensive repairs or replacement of otherwise useful structures. Figures 1 and 2 demonstrate the folly of inadequate or inappropriate maintenance. These two structures now require replacement at a cost tens of times greater than that of the preventive maintenance that could have extended their serviceability indefinitely.

LINK

Planning and Schedule Free Templates

Planning and Schedule Free Templates



Planning and schedule free templates.Download more than 150 free planning and schedule template. The templates contain Project planner Controls & Planning Management Plan Short Form v4 Controls & Planning Start Up Meeting Excel Time Schedule Template Project team communication plan Project time performance tracking Product or service cost tracker automatic time Schedule and cash flow Small business cash flow projection 12 month cash flow statement Statement of cash flows 12 month profit and loss projection 30 Chart Templates - Excel 2010 Procurement analysis worksheet Project performance tracking and reporting 2005 calendar on multiple worksheets Supplier analysis scorecard Weekly time sheet by client and project Weekly time sheet with tasks and overtime Weekly time sheet with breaks and more templates 



LINK

Analysis of Concrete Slabs on Grade Spreadsheet

Analysis of Concrete Slabs on Grade Spreadsheet



Analysis of concrete slabs on grade is a spreadsheet program written in MS-Excel for the purpose of analysis of concrete slabs on grade. Specifically, a concrete slab on grade may be subjected to concentrated post or wheel loading. Then for the given parameters, the slab flexural, bearing, and shear stresses are checked, the estimated crack width is determined, the minimum required distribution reinforcing is determined, and the bearing stress on the dowels at construction joints is checked. Also, design charts from the Portland Cement Association (PCA) are included to provide an additional method for determining/checking required slab thickness for flexure. The ability to analyze the capacity of a slab on grade subjected to continuous wall (line-type) load as well as stationary, uniformly distributed live loads is also provided. Loading data for fork trucks and AASHTO trucks is included.



LINK

Prestressed Concrete A Fundamental Approach

Advanced Concrete Technology Processes


ompletely revised to reflect the new ACI 318-08 Building Code and International Building Code, IBC 2009, this popular book offers a unique approach to examining the design of prestressed concrete members in a logical, step-by-step trial and adjustment procedure. Integrates handy flow charts to help readers better understand the steps needed for design and analysis. Includes a revised chapter containing the latest ACI and AASHTO Provisions on the design of post-tensioned beam end anchorage blocks using the strut-and-tie approach in conformity with ACI 318-08 Code. Offers a new complete section with two extensive design examples using the strut-and-tie approach for the design of corbels and deep beams. Features an addition to the elastic method of design, with comprehensive design examples on LRFD and Standard AASHTO designs of bridge deck members for flexure, shear and torsion, conforming to the latest AASHTO specifications. Includes a revised chapter on slender columns, including a simplified load-contour biaxial bending method which is easier to apply in desiign, using moments rather than loads in the reciprocal approach. A useful construction reference for engineers.


This fourth edition revises the previous text . There are 15 chapters covering: (1) introduction (historic development of structural concrete, basic design theory); (2) concrete producing materials; (3) concrete (mix design, tests, properties, quality control, placing and curving); (4) reinforced concrete (general chapter on design and safety); (5) flexure in beams; (6) shear and diagonal tension in beams; (7) torsion; (8) serviceability of beams and one-way slabs; (9) combined compression and bending: columns; (10) bond development of reinforcing bars; (11) design of two-way slabs and plates; (12) footings; (13) continuous reinforced concrete structures; (14) introduction to prestressed concrete; (15) seismic design of concrete structures. The appendices cover: (a) computer programs in Q-Basic; (b) tables and nomograms.

LINK

Pre-Dimensioning of Beams and Columns Excel Sheet

Pre-Dimensioning of Beams and Columns Excel Sheet



Pre-Dimensioning of beams and columns excel sheet conduct a preliminary calculation for centric loaded columns. For columns with bending components and other geometric boundary conditions, please contact our Technical Department.In the case of reinforced concrete, structural elements preliminary design stage has a high importance due to the contribution to the dead loads (the weight of the sectional elements) and to the total mass of the construction. Pre-dimensioning depends on various conditions such as stiffness (admissible deflection), ductility (proper sizing of structural elements so as to create areas with sufficient seismic energy dissipation capacity of deformation in post-elastic domain.


LINK

Advanced Concrete Technology Properties

Advanced Concrete Technology Properties


Fresh concrete is a transient material with continuously changing properties. It is, however,
essential that these are such that the concrete can be handled, transported, placed, compacted

and finished to form a homogenous, usually void-free, solid mass that realizes the full-
potential hardened properties. A wide range of techniques and systems are available for

these processes, and the concrete technologist, producer and user must ensure that the
concrete is suitable for those proposed or favoured.
Fresh concrete technology has advanced at a pace similar to many other aspects of
concrete technology over the past three decades, and indeed many of these advances have
been inter-dependent. For example, the availability of superplasticizers has enabled workable
concrete to be produced at lower water/binder ratios thus increasing the in-situ strength.


In this chapter, we will start by considering the property known as workability*,
including its definition and common methods of measurement. We will point out the
limitations of these, and show how this leads to the need for a more fundamental scientific
description of the behaviour of fresh cement pastes and concrete. We will then describe
how this has been achieved by applying the principles of rheology, and explain the
development and use of test methods which give a more complete understanding of the
behaviour. We will then discuss the effect on the rheological properties of a range of
constituent materials, including admixtures and cement replacement materials, and how
a knowledge of these properties can be used to advantage. The factors that influence the
loss of workability before setting are then briefly considered.

LINK

Capacity Calculations of Structural Members Excel Sheet

Capacity Calculations of Structural Members Excel Sheet



Capacity Calculations of Structural Members Excel Sheet calculate the capacity of different structural members such as beams modules , Columns, Foundations and Slabs.The excel sheet also allow you to design the required reinforcement area and a spacing of reinforcing bars within the cross-section of a concrete structure element. The RC Member Design module allows you to obtain a theoretical (required) area of reinforcement for selected concrete members.


LINK

THE ANALYSIS OF STRESS AND DEFORMATION

THE ANALYSIS OF STRESS AND DEFORMATION


This book was prepared for a course in the mechanics of deformable
bodies at the authors' institution, and is at a level suitable for advanced
undergraduate or first-year graduate students. It differs from the traditional
treatment by going more deeply into the fundamentals and giving less emphasis
to the design aspects of the subject. In the first two chapters the principles
of stress and strain are presented and a sufficient introduction is given to the
theory of elasticity so that the student can see how exact solutions of problems
can be derived, and can appreciate the nature of the approximations embodied
in some commonly used simplified solutions. The third chapter is devoted to
the bending of beams, and the fourth chapter treats the instability of elastic
systems.


Applications to axially symmetric problems, curved beams, and stress
concentrations are discussed in Chapter 5; applications to torsion problems
are discussed in Chapter 6; applications to problems of plates and shells are
discussed in Chapter 7. Applications to problems involving viscous and plastic
behavior are treated in Chapter 8, and problems of wave propagation are
treated in Chapter 9. An introduction to numerical methods of solving
problems is given in Chapter 10. An introduction to tensor notation by means
of the equations of elasticity is given in Appendix I. Experimental methods of
determining stresses by means of strain gages, brittle coatings, and photoelasticity
are described in Appendices I1 and 111. A brief introduction to
variational methods is presented in Appendix IV.

LINK

Computational Methods for Reinforced Concrete Structures

Computational Methods for Reinforced Concrete Structures


“There are no exact answers. Just bad ones, good ones and better ones. Engineering is the
art of approximation.” Approximation is performed with models. We consider a reality of
interest, e.g., a concrete beam. In a first view, it has properties such as dimensions, color,
surface texture. From a view of structural analysis the latter ones are irrelevant. A more
detailed inspection reveals a lot of more properties: composition, weight, strength, stiffness,
temperatures, conductivities, capacities, and so on. From a structural point of view some
of them are essential. We combine those essential properties to form a conceptual model.
Whether a property is essential is obvious for some, but the valuation of others might be
doubtful. We have to choose. By choosing properties our model becomes approximate
compared to reality. Approximations are more or less accurate.
On one hand, we should reduce the number of properties of a model. Any reduction of
properties will make a model less accurate. Nevertheless, it might remain a good model. On
the other hand, an over-reduction of properties will make a model inaccurate and therefore
useless. Maybe also properties are introduced which have no counterparts in the reality of
interest. Conceptual modeling is the art of choosing properties. As all other arts it cannot
be performed guided by strict rules.


A numerical model needs some completion as it has to be described by means of programming
to form a computational model. Finally, programs yield solutions through processing
by computers. The whole cycle is shown in Fig. 1.1. Sometimes it is appropriate to merge
the sophisticated sequence of models into the model.
A final solution provided after computer processing is approximate compared to the
exact solution of the underlying mathematical model. This is caused by discretization and
round-off errors. Let us assume that we can minimize this mathematical approximation
error in some sense and consider the final solution as a model solution. Nevertheless, the
relation between the model solution and the underlying reality of interest is basically an
issue. Both – model and reality of interest – share the same properties by definition or
conceptual modeling, respectively. Let us also assume that the real data of properties can
be objectively determined, e.g., by measurements.

LINK