Unified Design of Steel Structures

Unified Design of Steel Structures


Study the design of steel building structures per the 2005 unified specification, ANSI/AISC 360-05 Specification for Structural Steel Buildings with this key resource. Author Louis F. Geschwindner first builds the foundation for steel design and then explores the various member types in more detail. He provides guidance for those new to the field as well as an excellent review for practicing engineers looking to learn the provisions of the unified specification and to convert their practice from the old specifications to the new one.

Content :
Introduction 
Loads, Load Factors, and Load Combinations
Steel Building Materials
Tension Members
Compression Members
Bending Members in Structures 
Plate Girders
Beam-Columns and Frame Behavior
Composite Construction
Connection Elements
Simple Connections
Moment Connections

Steel Systems for Seismic Resistance



Chapter 1 includes an expanded discussion of structural integrity along with a discussion of the timing of adoption of the new provisions into the International Building Code. The integrated project introduced in this chapter for use throughout the book has been relocated to a new city from the 2nd edition and the framing system modified. This will provide new homework options for those who have implemented this project. A computer model using the RAM Structural System will be available on the book website to support inclusion of the integrated project in courses. Finally, an expanded discussion of reliability and statistics as it applies to structural steel design has been included.
Chapter 2 provides an expanded discussion of snow, wind and seismic loads and additional calculations for these environmental loads using ASCE 7.
Chapter 3 discusses the new steels approved by the 2016 Specification and the new approach taken by ASTM to the specification of high strength bolts.
Chapter 4 addresses tension members. The provisions have not changed, but there has been a revision in standard hole sizes for bolts. These new sizes have been implemented in the examples where appropriate.
Chapter 5 looks at compression members, and the Specification nomenclature change of KL to Lc has been implemented. A section and an example have been added to address gravity-only columns and their influence on the effective length of columns in lateral load resisting systems. The completely new approach for treatment of columns with slender elements, introduced with the 2016 Specification, is addressed. Single angle compression members and built-up compression members are discussed and examples provided.
Chapter 6 on flexural members includes a discussion of the shape factor and its significance. The use of Manual Table 3-10, the beam curves, with Cb not equal to 1.0, is expanded and a new example is included to illustrate the use of Manual Table 3-2, the economy tables, for noncompact beams. The treatment of tees, single angles and double angle beams has been expanded and examples included. Determination of shear strength for wide-flange members when the reduced resistance factor or increased safety factor must be used is now illustrated.
Chapter 7 addresses plate girders as doubly symmetric I-shapes built up from plates. It now includes a discussion of these plate girders with compact webs. The completely revised treatment of shear in plate girders included in the 2016 Specification has been incorporated, and the corresponding stiffener design has been expanded.

LINK

Core Wall Design Spreadsheets to Eurocode 2

Core Wall Design Spreadsheets to Eurocode 2



 core-walls  have been the most popular seismic force resisting system in western Canada
for many decades, and recently have become popular on the west coast of the US for high-rise buildings up to
600 ft (180 m) high. Without the moment frames that have traditionally been used in high-rise concrete
construction in the US, the system offers the advantages of lower cost and more flexible architecture. In the US,
such buildings are currently being designed using nonlinear response history analysis (NLRHA) at the
Maximum Considered Earthquake (MCE) level of ground motion. In Canada, these buildings are designed
using only linear dynamic (response spectrum) analysis at the MCE hazard level combined with various
prescriptive design procedures. This paper presents the background to some of the prescriptive design
procedures that have recently been developed to permit the safe design of high-rise core-wall buildings using
only the results of response spectrum analysis (RSA).

The series of European standards commonly known as “Eurocodes”, EN 1992 (Eurocode 2, in the

following also listed as EC2) deals with the design of reinforced concrete structures – buildings,
bridges and other civil engineering works. EC2 allows the calculation of action effects and of
resistances of concrete structures submitted to specific actions and contains all the prescriptions and
good practices for properly detailing the reinforcement.

In this spreadsheet , the principles of Eurocode 2, part 1-1 are applied to the design of core wall


LINK

Foundations of engineering geology

Foundations of engineering geology

Civil engineering is an exciting combination of science,
art, professional skill and engineering achievement which
always has to rely on the ground on which its structures
stand. Geology is therefore vital to success in civil
engineering, and this book brings to the reader those
many aspects of the geological sciences specifically
relevant to the profession.
This book is structured primarily for the student of civil
engineering who starts with no knowledge of geology but
is required to understand the ground conditions
and geological processes which, both literally and
metaphori cally, are the foundations of his future
professional activi ties. It also provides an accessible
source of information for the practising civil engineer.
All the material is presented in individual double-page
spreads. Each subject is covered by notes, diagrams,
tables and case histories, all in bite-sized sections instead
of being lost in a long continuous text. This style makes
the information very accessible; the reader can dip in and
find what he needs, and is also visually guided into
relevant associated topics. There is even some intended
repetition of small sections of material which are pertinent
to more than one aspect within the interrelated framework
of a geological understanding.

The contents of the book follow a basic university
course in engineering geology. The freestanding sections
and subsections permit infinite flexibility, so that any
lecturer can use the book as his course text while
tailoring his programme to his own personal style. The
single section summarizing soil strength has been
included for the benefit of geology students who do not
take a comprehensive course in soil mechanics within a

normal civil engineering syllabus.The sectionalized layout makes the information very
accessible, so that the practising engineer will find the
book to be a useful source when he requires a rapid
insight or reminder as he encounters geological problems
with difficult ground. Reference material has therefore
been added to many sections, mainly in tabulated form, to
provide a more complete data bank. The book has been
produced mainly in the inexpensive soft-bound format in
the hope that it will reach as large a market as possible.
The mass of data condensed into these pages has
been drawn from an enormous variety of sources. The
book is unashamedly a derived text, relying heavily on the
world-wide records of engineering geology. Material has
been accumulated over many years in a lecturing role. A
few concepts and case histories do derive from the
author’s personal research; but for the dominant part,
there is a debt of gratitude acknowledged to the innumer -
able geologists and civil engineers who have described
and communicated their own experiences and research.
All the figures have been newly drawn, and many are
derived from a combination of disparate sources. The
photographs are by the author.


Earth is an active planet in a constant state of change.
Geological processes continually modify the Earth’s
surface, destroy old rocks, create new rocks and add to
the complexity of ground conditions.
Cycle of geology encompasses all major processes,
which are cyclic, or they would grind to an inevitable halt.
Land: mainly erosion and rock destruction.
Sea: mainly deposition, forming new sediments.
Underground: new rocks created and deformed.
Earth movements are vital to the cycle; without them the
land would be eroded down to just below sea level.
Plate tectonics provide the mechanism for nearly all
earth movements (section 09). The hot interior of the
Earth is the ultimate energy source, which drives all
geological processes.
Geological time is an important concept. Earth is
4000M years old and has evolved continuously towards
its present form.

Most rocks encountered by engineers are 10–500M
years old. They have been displaced and deformed over
time, and some are then exposed at the surface by
erosional removal of rocks that once lay above them.
Underground structures and the ground surface have
evolved steadily through geological time.
Most surface landforms visible today have been
carved out by erosion within the last few million years,
while older landforms have been destroyed.
This time difference is important: the origin of the rocks
at the surface may bear no relationship to the present
environment. The classic example is Mt Everest, whose
summit is limestone, formed in a sea 300M years ago.
Geological time is difficult to comprehend but it must be
accepted as the time gaps account for many of the

contrasts in ground conditions.

Natural ground materials, rocks and soils, cover a great
range of strengths: granite is about 4000 times stronger
than peat soil.
Some variations in rock strength are summarized by
contrasting strong and weak rocks in the table.
Assessment of ground conditions must distinguish:
• Intact rock – strength of an unfractured, small block;
refer to UCS.
• Rock mass – properties of a large mass of fractured
rock in the ground; refer to rock mass
classes (section 25).
Note – a strong rock may contain so many fractures in a
hillside that the rock mass is weak and unstable.
Ground conditions also vary greatly due to purely local
features such as underground cavities, inclined shear

surfaces and artificial disturbance.

LINK

Punching Shear Strength Design of RC Slab According ACI318M-08

Punching Shear Strength Design of RC Slab According ACI318M-08



The main objective of this sheet is to evaluate the effect of design tje RC slab for punching shear strength . The increasing of the punching shear strength and deformation capacity
 when subjected to patch load was studied here.
An experimental study was carried out on reinforced concrete slabs under a central patch load with
circular, square and rectangular shapes of patch areas. A single concrete mix design was used
throughout the test program. All of slab specimens were reinforced with distributed mesh
reinforcement with equal steel ratios in both directions. The validation of the experimental work
was made by analyzing the tested slabs by finite element method under cracking load. The results
obtained by the finite element method were found to compare well with those obtained
experimentally. In order to calculate the ductility for the tested slabs, the punching load has been
determined by applying the published failure criterion and a load-rotation relationship obtained
from semi-empirical relationship for the tested slabs. Conclusions on the influence of patch area on
the punching shear capacity of reinforced concrete slabs were drawn. The experimental results
confirm that the strength and deformation capacity are slightly influenced by the shape of the patch
area. Among all specimens, the slabs with circular shape of patch area exhibited the best
performance in terms of ductility and splitting failure.

In flat-plate floors, slab-column connections are subjected to high shear stresses produced by the transfer of the internal forces between the columns and the slabs (ACI-421.1R-08, 2008; ACI-421.1-99, 1999). Normally it is desired to increase the slab thickness or using drop panels or column capitals of exceptionally high strength for shear in reinforced concrete slab around the supporting column. Occasionally, methods to increase punching shear resistance without modifying the slab thickness are often preferred (Cheng and Montesinos, 2010). The ways to transfer the force from column to the slab need to be studied to increase the shear resistance. Several reinforcement alternatives for increasing punching shear resistance of slab-column connections, including bent-up bars (Hawkins et al., 1974; Islam and Park, 1976), closed stirrups (Islam and Park, 1976), shearheads (Corley and Hawkins, 1968), and shear studs (Dilger and Ghali, 1981), have been evaluated in the past five decades. But there is a little experimental and theoretical information about the influence of patch area or cross section area shape for supporting column in the reinforced concrete shear resistance.



LINK

Introduction to Civil Engineering Systems

Introduction to Civil Engineering Systems


The civil engineering discipline involves the development of structural, hydraulic, geotechnical,
construction, environmental, transportation, architectural, and other civil systems that address societies’
infrastructure needs. The planning and design of these systems are well covered in traditional
courses and texts at most universities. In recent years, however, universities have increasingly
sought to infuse a “systems” perspective to their traditional civil engineering curricula. This development
arose out of the recognition that the developers of civil engineering systems need a solid set
of skills in other disciplines. These skills are needed to equip them further for their traditional tasks
at the design and construction phases and also to burnish their analytical skills for other less-obvious
or emerging tasks at all phases of system development.
The development of civil engineering systems over the centuries and millennia has been characterized
by continual improvements that were achieved mostly through series of trial-and-error as
systems were constructed and reconstructed by learning from past mistakes. At the current time,
the use of trial-and-error methods on real-life systems is infeasible because it may take not only
several decades but also involve excessive costs in resources and, possibly, human lives before the
best system can be finally realized. Also in the past, systems have been developed in ways that were
not always effective or cost-effective. For these and other reasons, the current era, which has inherited
the civil engineering systems built decades ago, poses a unique set of challenges for today’s
civil engineers. A large number of these systems, dams, bridges, roads, ports, and so on are functionally
obsolescent or are approaching the end of their design lives and are in need of expansion,
rehabilitation, or replacement. The issue of inadequate or aging civil infrastructure has deservedly
gained national attention due to a series of publicized engineering system failures in the United
States, such as the New Orleans levees, the Minnesota and Seattle interstate highway bridges, and
the New York and Dallas sewers, and in other countries. The current problem of aging infrastructure
is further exacerbated by increased demand and loading fueled by population growth, rising
user expectations of system performance, increased desire for stakeholder participation in decisionmaking
processes, terrorism threats, the looming specter of tort liability, and above all, inadequate
funding for sustained preservation and renewal of these systems.

As such, civil engineers of today need not only to develop skills in the traditional design areas
but also to continually seek and implement traditional and emerging tools in other related areas
such as operations research, economics, law, finance, statistics, and other areas. These efforts can
facilitate a more comprehensive yet holistic approach to problem solving at any phase of the civil
engineering system development cycle. This way, these systems can be constructed, maintained,
and operated in the most cost-effective way with minimal damage to the environment, maximum
system longevity, reduced exposure to torts, optimal use of the taxpayers’ dollar, and other benefits.
Unfortunately, at the current time, graduating engineers enter the workforce with few or no skills
in systems engineering and learn these skills informally only after several decades. With limited
skill in how to integrate specific knowledge from external disciplines into their work, practicing
engineers will be potentially handicapped unless their organizations provide formal training in the

concepts of sytems engineering. This text addresses these issues.


The first part of this text discusses the historical evolution of the various engineering disciplines
and general concepts of systems engineering. This includes formal definitions, systems classifications,
systems attributes, and general and specific examples of systems in everyday life and in civil
engineering. The part also identifies the phases of development of civil systems over their life cycle
and discusses the tasks faced by civil systems engineers at each phase. Most working engineers are
typically involved in only one or two of these phases, but it is important for all engineers to acquire
an overall bird’s eye view of all phases so that decisions they make at any phase are holistic and
within the context of the entire life cycle of their systems. The next two parts discuss the tasks that
civil engineers encounter at each phase and the tools they need to address these tasks. For example,
at the needs assessment phase, one possible task is to predict the level of expected usage of the system,
and the tool for this task could be statistical modeling or simulation. Certain tools are useful in
more than one phase. Given this background, Part IV provides a detailed discussion of each phase
of civil systems development and presents specific examples of tasks and tools used to address
questions at these phases. Part V presents topics that may seem peripheral but are critical to civil
systems development, such as legal issues, ethics, sustainability, and resilience, and discusses their
relevance at each phase.
Clearly, this text differs from other texts in the manner in which it presents the material. The
systems tasks and tools are presented not in a scattered fashion but rather in the organized context
of a phasal framework of system development. Why is it so important to view the entire life cycle of
civil engineering systems within a phasal framework? And why do we need to acquire those skills
that are needed for the tasks at each phase? One reason is the typically large expense involved in
the provision of such facilities. Every year, several trillion dollars are invested worldwide in civil
engineering systems, to build new facilities or to operate and maintain existing ones. The beneficial
impacts of these investments permeate every sphere of our lives including safety, mobility, security,
and the economy and thus need to be identified and measured systematically. Also, adverse
impacts such as environmental degradation, community disruption, and inequities are often evident
and need to be assessed and mitigated. In summation, given the large expanse and value of
civil engineering assets, the massive volume of national and state investments annually to build and
operate these systems, and the multiplicity of stakeholders, there is need for a comprehensive yet
integrated approach to the planning, design, implementation, operations, and preservation of these
systems. A second reason for advocating an organized systems approach is the nature of recent and
ongoing trends in the socioeconomic environment: at the current time of tight budgets, increasing
loadings and demand, aging infrastructure, global economic changes, and increased need for security
and safety, civil engineering systems are facing scrutiny more than ever before and the biggest
bang is now sought for every dollar spent on these systems. As such, civil system engineers are increasingly being called upon to render account of their fiduciary stewardship of the public infrastructure and assets. This is best done when the development of such systems is viewed within a phasal framework, when civil engineering system managers acquire the requisite tools needed to address the tasks at each phase, and when these managers provide evidence of organized planning for long-term life-cycle development of their systems.

LINK

Canadian Seismic Design of Steel Structures

Canadian Seismic Design of Steel Structures



Design of Steel Structures of the Canadian Standards Association (CSA) governs the design of the majority of steel structures in Canada. Clause 27 of the standard includes the earthquake design provisions for seismic force resisting systems for which ductile seismic response is expected. Technical changes and new requirements have been incorporated in the 2009 edition of CSA S16, including modifications of the expected material properties for HSS members, consideration of protected zones, definitions of brace probable compressive and tensile resistances for capacity design and special requirements for braces intersecting columns between floors for concentrically braced steel frames, new seismic provisions for buckling restrained braced steel frames, design and detailing requirements for built-up tubular ductile links in eccentrically braced steel frames, changes to the requirements for ductile steel plate walls and for plate walls with limited ductility, including allowances for perforations and corner cut-outs in infill plates, and special provisions for steel frames of the Conventional Construction category above 15 m in height. These modifications were developed in parallel with the 2010 National Building Code of Canada (NBCC). The paper summarizes the new CSA S16-09 seismic design requirements with reference to NBCC 2010.

Basic capacity design provisions are given in CSA S16 to ascertain that minimum strength hierarchy exists along the lateral load path such that the intended ductile energy dissipation mechanism is mobilized and the integrity of the structure is maintained under strong ground shaking. In the design process, the yielding components of the SFRS may be oversized compared to the specified design seismic forces, as would be the case when drift limits, minimum member sizes or non-seismic load combinations govern the design. In this case, it is specified both in NBCC 2010 and CSA S16 that the design forces in capacity-protected elements need not exceed those induced by a storey shear determined with RoRd = 1.3. This upper bound essentially corresponds to the elastic seismic force demand reduced by 1.3, recognizing that nonyielding components will likely possess minimum overstrength. This 1.3 reduction factor only applies if the governing failure mode is ductile, and RoRd = 1.0 must be used otherwise.

This file contains formatted spreadsheets to perform the following calculations:
 - Section 1: Area of equivalent diagonal brace for plate wall analysis (Walls).
 - Section 2: Design of link in eccentrically braced frames (EBF).
 - Section 3: Design of Bolted Unstiffened End Plate Connection (BUEP).
 - Section 4: Design of Bolted Stiffened End Plate Connection (BSEP).
 - Section 5: Design of Reduced Beam Section Connection (RBS).
 - Section 6: Force reduction factor for friction-damped systems (Rd_friction).

 Additionally, this file contains the following tables:
 - Valid beam sections for moment-resisting connections (B_sections).
 - Valid column sections for moment-resisting connections (C_sections).
 - Valid bolt types for moment-resisting connections (Bolts).
 - Database of properties of all sections (Sections Table).


LINK

Modern Experimental Stress Analysis

Modern Experimental Stress Analysis


This book is based on the assertion that, in modern stress analysis, constructing the model
is constructing the solution—that the model is the solution. But all model representations
of real structures must be incomplete; after all, we cannot be completely aware of every
material property, every aspect of the loading, and every condition of the environment,
for any particular structure. Therefore, as a corollary to the assertion, we posit that a
very important role of modern experimental stress analysis is to aid in completing the
construction of the model.

What has brought us to this point? On the one hand, there is the phenomenal growth
of finite element methods (FEM); because of the quality and versatility of the commercial
packages, it seems as though all analyses are now done with FEM. In companies
doing product development and in engineering schools, there has been a corresponding
diminishing of experimental methods and experimental stress analysis (ESA) in particular.
On the other hand, the nature of the problems has changed. In product development,
there was a time when ESA provided the solution directly, for example, the stress at a
point or the failure load. In research, there was a time when ESA gave insight into the
phenomenon, for example, dynamic crack initiation and arrest. What they both had in
common is that they attempted to give “the answer”; in short, we identified an unknown
and designed an experiment to measure it. Modern problems are far more complex, and
the solutions required are not amenable to simple or discrete answers.

In truth, experimental engineers have always been involved in model building, but the
nature of the model has changed. It was once sufficient to make a table, listing dimensions
and material properties, and so on, or make a graph of the relationship between quantities,
and these were the models. In some cases, a scaled physical construction was the model.
Nowadays the model is the FEM model, because, like its physical counterpart, it is a
dynamic model in the sense that if stresses or strains or displacements are required, these
are computed on the fly for different loads; it is not just a database of numbers or graphs.
Actually, it is even more than this; it is a disciplined way of organizing our current
knowledge about the structure or component. Once the model is in order or complete, it
can be used to provide any desired information like no enormous data bank could ever
do; it can be used, in Hamilton’s words, “to utter its revelations of the future”. It is this
predictive and prognostic capability that the current generation of models afford us and
that traditional experimental stress analysis is incapable of giving.


There are two main types of stress analyses. The first is conceptual, where the structure
does not yet exist and the analyst is given reasonable leeway to define geometry, material,
loads, and so on. The preeminent way of doing this nowadays is with the finite element
method (FEM). The second analysis is where the structure (or a prototype) exists, and it
is this particular structure that must be analyzed. Situations involving real structures and
components are, by their very nature, only partially specified. After all, the analyst cannot
be completely aware of every material property, every aspect of the loading, and every
condition of the environment for this particular structure. And yet the results could be
profoundly affected by any one of these (and other) factors. These problems are usually
handled by an ad hoc combination of experimental and analytical methods—experiments
are used to measure some of the unknowns, and guesses/assumptions are used to fill in
the remaining unknowns. The central role of modern experimental stress analysis is to
help complete, through measurement and testing, the construction of an analytical model
for the problem. The central concern in this book is to establish formal methods for
achieving this.

Experimental methods do not provide a complete stress analysis solution without additional
processing of the data and/or assumptions about the structural system. Figure I.1

shows experimental whole-field data for some sample stress analysis problems—these
example problems were chosen because they represent a range of difficulties often encountered
when doing experimental stress analysis using whole-field optical methods. (Further
details of the experimental methods can be found in References [43, 48] and will be elaborated
in Chapter 2.) The photoelastic data of Figure I.1(b) can directly give the stresses
along a free edge; however, because of edge effects, machining effects, and loss of
contrast, the quality of photoelastic data is poorest along the edge, precisely where we
need good data. Furthermore, a good deal of additional data collection and processing is
required if the stresses away from the free edge is of interest (this would be the case in
contact and thermal problems). By contrast, the Moir´e methods give objective displacement
information over the whole field but suffer the drawback that the fringe data must be
spatially differentiated to give the strains and, subsequently, the stresses. It is clear from
Figure I.1(a) that the fringes are too sparse to allow for differentiation; this is especially
true if the stresses at the load application point are of interest. Also, the Moir´e methods
invariably have an initial fringe pattern that must be subtracted from the loaded pattern,
which leads to further deterioration of the computed strains. Double exposure holography
directly gives the deformed pattern but is so sensitive that fringe contrast is easily lost
(as is seen in Figure I.1(c)) and fringe localization can become a problem. The strains
in this case are obtained by double spatial differentiation of the measured data on the
assumption that the plate is correctly described by classical thin plate theory—otherwise

it is uncertain as to how the strains are to be obtained.

LINK

Advanced Stress and Stability Analysis: worked examples

Advanced Stress and Stability Analysis


This book is not a collection of problems in the ordinary sense. The exercises
are not intended for beginning students in a “Strength of Materials”
course but for those who have completed the course. Neither does the book
intend to interpret a full coursev, but it draws the reader’s attention either to
some speci…c problems that are not at all included in the course, or to such
problems that often escape the student’s attention not only in the process of
training but also in their further engineering activity.
The problem complexity is also di¤erent. Some are ordinary problems and
others are rather complicated. Some of them require only common knowledge
and quickness of wit and others require application of primary aspects of
the theory of elasticity. Many of them are complicated at …rst glance, but
their solution may be found to be unexpectedly simple. In other cases the
at …rst glance obvious solution may be incorrect. Even experienced readers
may …nd themselves making mistakes. That is why all problems are provided
with detailed solutions for those who are interested in the principles of the
problem-solving process, or to provide the possibility for testing the obtained
results in case the readers intend to solve the problems in their own manner.
Experience shows that students are often dissatis…ed with the solutions
of typical problems presented in ordinary textbooks. Many students have
questions that are beyond the training course and require more fundamental
understanding. They naturally want to test themselves in solving more complex
and more interesting problems where alertness, knowledge, and intuition
are required. The book is aimed at the demands of those students, most of all.

New problems appear not at a writing-table. They arise as a result of new
developments and sometimes simply by friendly conversations, as a result
of opinion exchange and creative search of suitable statements. The author
was fortunate for encountering such kind discussions with colleagues and

specialists and extremely thanks his lucky stars and friends for that.


This is a book, written by the famous late Russian engineer and educator
Vsevolod I.Feodosiev, who formed the tradition of stress and stability analysis
for generations of engineers and researchers working in those …elds, where the
Soviet Union accomplished the greatest technological breakthrough of the
20th century – a race into space.
Prof. Feodosiev continued the best tradition of the Russian engineering
school with his innovative and unique concepts based on deep penetration
into the mechanical and practical nature of problems. Four times revised and
republished in Russia and translated into some languages, the book became
a classical desk text for training of top mechanical specialists. Written with
a great pedagogical skill, it gives to the reader a fresh and original outlook
on analysis of some advanced engineering problems.
The research and educational work of Prof. V.I. Feodosiev was carried
out in the Bauman Moscow State Technical University (BMSTU), where he
studied and worked for over 50 years. For a long time Prof. V.I. Feodosiev
was head of the Space Missile Engineering Department.
His outstanding ability, extraordinary memory and diligence revealed itself
quite early. Feodosiev’s …nal student project was quali…ed as a PhD thesis.
He was awarded his DSc degree for research in application of ‡exible shells
in machines when he was 27 years old.
For 50 years Prof. Feodosiev delivered in BMSTU his course of lectures
on strength of materials. His textbook of the course, republished more than
ten times, became the basic book on the subject for top Russian technical
universities and was awarded the State Prize. V.I. Feodosiev was awarded
also the Lenin Prize (the main scienti…c award in the Soviet Union) for his
contribution into fundamental tree-volume monograph ”Strength Analysis in
Mechanical Engineering”.
The fundamentals of strength and reliability in aero-space engineering
were published in his monographs: ”Elastic Elements of Precision Engineering”,
”Strength Analysis of High-Loaded Parts of Jet Engines”, ”Introduction
into Missile Engineering”.
Deep insight into engineering problems, clearness of concepts and elegance
of solutions enhanced by undoubted pedagogical talent are the main features
of Feodosiev’s style.

LINK

Reanalysis of Structures: A Unified Approach for Linear, Nonlinear, Static and Dynamic Systems

Reanalysis of Structures: A Unified Approach for Linear, Nonlinear, Static and Dynamic Systems


Structural analysis is a most exciting field of activity, but it is only a support
activity in the field of structural design. Analysis is a main part of the
formulation and the solution of any design problem, and it often must be
repeated many times during the design process. The analysis process helps
to identify improved designs with respect to performance and cost.
Referring to behavior under working loads, the objective of the analysis
of a given structure is to determine the internal forces, stresses and displacements
under application of the given loading conditions. In order to
evaluate the response of the structure it is necessary to establish an analytical
model, which represents the structural behavior under application of
the loadings. An acceptable model must describe the physical behavior of
the structure adequately, and yet be simple to analyze. That is, the basic
assumptions of the analysis will ensure that the model represents the problem
under consideration and that the idealizations and approximations used
result in a simplified solution. This latter property is essential particularly
in the design of complex or large systems.

The overall effectiveness of an analysis depends to a large degree on the
numerical procedures used for the solution of the equilibrium equations
[1]. The accuracy of the analysis can, in general, be improved if a more refined
model is used. In practice, there is a tendency to employ more and
more refined models to approximate the actual structure. This means that
the cost of an analysis and its practical feasibility depend to a considerable
degree on the algorithms available for the solution of the resulting equations.
The time required for solving the equilibrium equations can be a
high percentage of the total solution time, particularly in nonlinear analysis
or in dynamic analysis, when the solution must be repeated many times.
An analysis may not be possible if the solution procedures are too costly.
Because of the requirement to solve large systems, much research effort

has been invested in equation solution algorithms.

In elastic analysis we refer to behavior under working loads. The forces
must satisfy the conditions of equilibrium, and produce deformations compatible
with the continuity of the structure and the support conditions. That
is, any method must ensure that both conditions of equilibrium and compatibility
are satisfied. In linear analysis we assume that displacements
(translations or rotations) vary linearly with the applied forces. That is, any
increment in a displacement is proportional to the force causing it. This assumption
is based on the following two conditions:
The material of the structure is elastic and obeys Hooke's law.
All deformations are assumed to be small, so that the displacements do
not significantly affect the geometry of the structure and hence do not
alter the forces in the members. Thus, the changes in the geometry are

small and can be neglected.


Repeated analysis, or reanalysis, is needed in various problems of structural
analysis, design and optimization. In general, the structural response
cannot be expressed explicitly in terms of the structure properties, and
structural analysis involves solution of a set of simultaneous equations.
Reanalysis methods are intended to analyze efficiently structures that are
modified due to various changes in their properties. The object is to evaluate
the structural response (e.g. displacements, forces and stresses) for such
changes without solving the complete set of modified simultaneous equations.
The solution procedures usually use the response of the original
structure. Some common problems, where multiple repeated analyses are
needed, are described in the following.

In structural optimization the solution is iterative and consists of
repeated analyses followed by redesign steps. The high computational
cost involved in repeated analyses of large-scale problems is one of the
main obstacles in the solution process. In many problems the analysis
part will require most of the computational effort, therefore only
methods that do not involve numerous time-consuming implicit analyses
might prove useful. Reanalysis methods, intended to reduce the
computational cost, have been motivated by some typical difficulties
involved in the solution process. The number of design variables is
usually large, and various failure modes under each of several load
conditions are often considered. The constraints are implicit functions of
the design variables, and evaluation of the constraint values for any
assumed design requires the solution of a set of simultaneous analysis
equations.

In structural damage analysis it is necessary to analyze the structure for
various changes due to deterioration, poor maintenance, damage, or
accidents. In general many hypothetical damage scenarios, describing
various types of damage, should be considered. These include partial or
complete damage in various elements of the structure and changes in the
support conditions. Numerous analyses are required to assess the
adequacy of redundancy and to evaluate various hypothetical damage
scenarios for different types of damage.

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Retaining Wall with Anchors Analysis and Design Spreadsheet

Retaining Wall with Anchors Analysis and Design Spreadsheet



This spreadsheet provides the design and analysis of retaining wall with anchors.
Retaining walls with anchors shall be dimensioned to ensure that the total lateral
load, Ptotal, plus any additional horizontal loads, are resisted by the horizontal component
of the anchor Factored Design Load Thi, of all the anchors and the reaction, R, at or below
the bottom of the wall. The embedded vertical elements shall ensure stability and sufficient
passive resistance against translation. The calculated embedment length shall be the greater
of that calculated by the Designer or Geotechnical Services.

Typical design steps for retaining walls with ground anchors are as follows:

Step 1 : Establish project requirements including all geometry, external loading conditions
(temporary and/ or permanent, seismic, etc.), performance criteria, and construction
constraints. Consult with Geotechnical Services for the requirements.

Step 2 : Evaluate site subsurface conditions and relevant properties of the in situ soil or
rock; and any specifications controlled fill materials including all materials strength
parameters, ground water levels, etc. This step is to be performed by Geotechnical Services.

Step 3 : Evaluate material engineering properties, establish design load and resistance
factors, and select level of corrosion protection. Consult with Geotechnical
Services for soil and rock engineering properties and design issues.

Step 4 : Consult with Geotechnical Services to select the lateral earth pressure distribution
acting on back of wall for final wall height. Add appropriate water, surcharge, and
seismic pressures to evaluate total lateral pressure. Check stability at intermediate
steps during contruction. Geotechnical numerical analysis may be required to
simulate staged construction. Consult Geotechnical Services for the task, should it be required.

Step 5 : Space the anchors vertically and horizontally based upon wall type and wall height.
Calculate individual anchor loads. Revise anchor spacing and geometry if necessary.

Step 6 : Determine required anchor inclination and horizontal angle based on right-of-way
limitations, location of appropriate anchoring strata, and location of underground structures.

Step 7 : Resolve each horizontal anchor load into a vertical force component and a force
along the anchor.

Step 8 : Structure Design checks the internal stability and Geotechnical Services checks the
external stability of anchored system. Revise ground anchor geometry if necessary.

Step 9 : When adjacent structures are sensitive to movements Structure Design and
Geotechical Services shall jointly decide the appropriate level and method of
analysis required. Revise design if necessary. For the estimate of lateral wall
movements and ground surface settlements, geotechnical numerical analysis is
most likely required. Consult with Geotechnical Services for the task, should it be required.

Step 10 : Structure Design analyzes lateral capacity of pile section below excavation subgrade.
Geotechnical Services analyzes vertical capacity. Revise pile section if necessary.

Step 11 : Design connection details, concrete facing, lagging, walers, drainage systems, etc.
Consult with Geotechnical Services for the design of additional drainage needs.


Step 12 : Design the wall facing architectural treatment as required by the Architect.



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Aboveground Storage Tanks

Aboveground Storage Tanks


Aboveground storage tanks (ASTs) have been around since the inception
of industrial processing, but surprisingly, very little practical
engineering or general information is readily available to the tank
inspector, engineer, or operator. Why this is can only be speculated
on. Perhaps, the concept of a tank is so simple that it fosters a belief
that there is little complexity to them and they do not warrant expenditures
of resources. Perhaps, the tank owner believes that it is
appropriate to relegate all tank issues to the care of the manufacturer.
Perhaps, it is because they are generally reliable pieces of equipment
or are considered infrastructure.

Whatever the case, for those who have had to deal with ASTs,
understanding the complex issues and problems and implementing
good design, inspection, operational or environmental solutions to
AST problems have been all but simple. Well-intentioned individuals
and companies in need of sound engineering information frequently
make major blunders in areas of design, inspection, or safety. This
often results in high costs, shortened equipment life, ineffective inspection
programs, environmental damage, or accidents and injuries

as well as the threats of more national and state legislation.

In recent years there has been an increasing polarization between
industry, environmental groups, regulators, and the public. Each
facility which operates with tanks carries much more risk than just
damaging its equipment. Regardless of cause, injuries, fatalities, and
incidents all create a kind of press that can be used against the entire
industry with no real benefit. So rather than proper application of
industry standards to maintain facility integrity on a site-specific
basis, we are seeing a trend where the design, inspection, and operation
of facilities is being politically controlled or regnlated. This is the
worst possible way of running these facilities because it does not
address the fundamental causes of the problems and it creates inefficiencies

of mammoth proportion. It also directs resources away from where they are more needed for the public good such as higher risk
operations or in other places in the facility. The political approach to
controlling tank facilities penalizes the companies willing to do things
right while not really fIxing the fundamental problems. However, this
is not to say that there should be no responsibility to operate these
facilities carefully, safely, and in accordance with recogoized and generally
accepted good practices. In large part the situation we are in
now is a result of the industrial reticence to speak up on issues, to
promote information such as contained in this book to reduce the incidents
which form the basis of regulations, and to be more proactive in
the regulatory process than simply writing industry-recommended
practices or standards.


The purpose of the book then is to help break the cycle described
above by introducing appropriate information that will make any
tank facilities safer, more reliable, and not in need of more stringent
regulations. SpecifIcally, this book can help any individual, company,
or industry using ASTs to improve their performance in the areas of
safety (both employee and the public), environmentally responsible
operations, and implementation of good practices. Fortunately, this
can be done with relatively small expenditures of time and effort
when armed with knowledge and experience.

This book covers fundamental principles of aboveground storage
tanks as well as more advanced principles such as seismic engineering
needed for work in susceptible areas. It will be of interest to engineers,
inspectors, desigoers, regulators, and owners as well as to any
other person involved in any of the many specialized topics related to
tanks. Each topic is treated from a perspective that the reader knows
nothing and works up to a fairly advanced level so that the reading
may be selective as appropriate and as needed. Where the topic
becomes extremely advanced or where only unproved theories exist,
then this is noted and further references are made available. One of
the best sources of information about tanks, petroleum related issues,
and all kinds of problems associated with the petroleum business is
the American Petroleum Institute (API). This organization has produced
numerous high-quality standards, recommended practices, and
publications from which the reader may have access to the state of

the art in these topics.

Although the word tank identifIes only a single type or piece of equipment
in an industrial facility, tanks have been used in innumerable
ways both to store every conceivable liquid, vapor, or even solid and
in a number of interesting processing applications. For example, they
perform various unit operations in processing such as settling, mixing,
crystallization, phase separation, heat exchange, and as reactors.
Here we address the tank primarily as a liquid storage vessel with
occasional discussion regarding specialized applications. However, the
principles outlined here will, in many ways, apply generally to tanks

in other applications as well as to other equipment.


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