Interactive Design of Semirigid Steel Frames

By : Balaur S. Dhillon, Fellow,ASCE, and James W. O'Malley III, Associate Member, ASCE

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Inelastic Design of Infilled Frames

By : Abolghasem Saneinejad and Brian Hobbs

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FINITE ELEMENT ANALYSIS OF REINFORCED CONCRETE BEAMS

By : D. NGO and A.C. Scordelis

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Self-Compacting Concrete

By : Hajime Okamura and Masahiro Ouchi

Abstract :
Self-compacting concrete was first developed in 1988 to achieve durable concrete structures. Since then, various investigations have been carried out and this type of concrete has been used in practical structures in Japan, mainly by large construction companies. Investigations for establishing a rational mix-design method and self-compactability testing methods have been carried out from the viewpoint of making self-compacting concrete a standard concrete.

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AERODYNAMIC STABILITY ANALYSIS OF CABLE-STAYED BRIDGES

By : M.S. Pfeil and R.C. Batista
Abstract : Cable-stayed bridges under wind loading exhibit dynamic behaviors that depended on the aeroelastic forces and coupling among vibration modes.

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WIND-INDUCED NONLINEAR LATERAL-TORSIONAL BUCKLING OF CABLE-STAYED BRIDGES

By Virote Boonyapinyo, Hitoshi Yamada, and Toshio Miyata

ABSTRACT: A finite element approach to calculate directly the critical wind velocity for the nonlinear lateral-torsional buckling instability of long-span cable stayed bridges under the displacement-dependent wind loads is presented. An analytical modeling of wind-induced lateral-torsional buckling is formulated taking into account the three components of displacement-dependent wind loads as well as geometric nonlinearity. A combination of the eigenvalue analysis and the updated bound algorithm for wind velocity is applied to automatically calculate the critical wind velocity. The results show that the incorporation of the three components of displacement-dependent wind loads as well as the geometric nonlinearity in the analytical modeling of the lateral-torsional buckling instability results in significant reduction in the critical wind velocity compared with both the conventional non-linear torsional divergence and linearized lateral-torsional buckling.

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Structural Analysis with Finite Elements

The finite element method has become an indispensible tool in structural analysis, and tells an unparalleled success story. With success, however, came criticism, because it was noticeable that knowledge of the method among practitioners did not keep up with success. Reviewing engineers complain that the method is increasingly applied without an understanding of structural behavior.

Often a critical evaluation of computed results is missing, and frequently a basic understanding of the limitations and possibilities of the method are nonexistent. But a working knowledge of the fundamentals of the finite element method and classical structural mechanics is a prerequisite for any sound finite element analysis. Only a well trained engineer will have the skills to critically examine the computed results.

Finite element modeling is more than preparing a mesh connecting the elements at the nodes and replacing the load by nodal forces. This is a popular model but this model downgrades the complex structural reality in such a way that—instead of being helpful—it misleads an engineer who is not well acquainted with finite element techniques.

The object of this book is therefore to provide a foundation for the finite element method from the standpoint of structural analysis, and to discuss questions that arise in modeling structures with finite elements. What encouraged us in writing this book was that—thanks to the intensive
research that is still going on in the finite element community—we can explain the principles of finite element methods in a new way and from a new perspective by making ample use of influence functions. This approach should appeal in particular to structural engineers, because influence functions are a genuine engineering concept and are thus deeply rooted in classical structural mechanics, so that the structural engineer can use his engineering knowledge and insight to assess the accuracy of finite element results or to discuss the modeling of structures with finite elements.

Just as a change in the elastic properties of a structure changes the Green’s functions or influence functions of the structure so a finite element mesh effects a shift of the Green’s functions. We have tried to concentrate on ideas, because we considered these and not necessarily the technical details to be important. The emphasis should be on structural mechanics and not on programming the finite elements, and therefore we have also provided many illustrative examples.

Finite element technology was not developed by mathematicians, but by engineers (Argyris, Clough, Zienkiewicz). They relied on heuristics, their intuition and their engineering expertise, when in the tradition of medieval craftsmen they designed and tested elements without fully understanding the exact background. The results were empirically useful and engineers were grateful because they could suddenly tackle questions which were previously unanswerable. After these early achievements self-confidence grew, and a second epoch followed that could be called baroque: the elements became more and more complex (some finite element programs offered 50 or more elements) and enthusiasm prevailed. In the third phase, the epoch of “enlightment” mathematicians became interested in the method and tried to analyze the method with mathematical rigor. To some extent their efforts were futile or extremely difficult, because engineers employed “techniques” (reduced integration, nonconforming elements, discrete Kirchhoff elements) which had no analogy in the calculus of variations. But little by little knowledge increased, the gap closed, and mathematicians felt secure enough with the method that they could provide reliable estimates about the behavior of some elements.

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REINFORCED CONCRETE DEEP BEAMS

This book is designed as an international reference work on the behaviour, design and analysis of reinforced concrete deep beams. It is intended to meet the needs of practising civil and structural engineers, consulting engineering and contracting firms, research institutes, universities and colleges.

Reinforced concrete deep beams have many useful applications, particularly in tall buildings, foundations and offshore structures. However, their design is not covered adequately by national codes of practice: for example the current British Code BS 8110, explicitly states that ‘for design of deep beams, reference should be made to specialist literature’. The major codes and manuals that contain some discussion of deep beams include the American ACI Building Code, the draft Eurocode EC/2, the Canadian Code, the CIRIA Guide No. 2, and Reynolds and Steedman’s Reinforced Concrete Designer’s Handbook. Of these, the CIRIA Guide No. 2: Design of Deep Beams in Reinforced Concrete, published by the Construction Industry Research and Information Association in London, gives the most comprehensive recommendations.

The contents of the book have been chosen with the following main aims: (i) to review the coverage of the main design codes and the CIRIA Guide, and to explain the fundamental behaviour of deep beams; (ii) to provide information on design topics which are inadequately covered by the current codes and design manuals: deep beams with web openings, continuous deep beams, flanged deep beams, deep beams under top and bottom loadings and buckling and stability of slender deep beams; (iii) to give authoritative reviews of some powerful concepts and techniques for the design and analysis of deep beams such as the softened-truss model, the plastic method and the finite element method.

The contributing authors of this book are so eminent in the field of structural concrete that they stand on their own reputation and I feel privileged to have had the opportunity to work with them. I only wish to thank them for their high quality contributions and for the thoroughness with which their chapters were prepared.

I wish to thank Mr A.Stevens, Mr J.Blanchard and Mr E.Booth of Ove Arup and Partners for valuable discussions, and to thank Emeritus Professor R.H.Evans, C.B.E., of the University of Leeds for his guidance over the years. Finally, I wish to thank Mrs Diane Baty for the much valued secretarial support throughout the preparation of this volume.

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Discussion of “Unloading and Reloading Stress-Strain Model for Confined Concrete” by Junichi Sakai and Kazuhiko Kawashima

by Asad Esmaeily, A.M.ASCE; Steven D. Hart; and`Brandy Gaitan

In this paper, the authors, Sakai and Kawashima, propose a “comprehensive . . . model . . . that takes into account the effect of repeated unloading and reloading and partial loading.” This model was evaluated by conducting several tests on concrete cylinders confined by carbon-fiber-reinforced polymer
CFRP material.

Three standard 150 mm
300 mm
6 in.
12 in. concrete cylinders were cast and cured for 28 days in a moist curing room. Two strain gauges with a length of 50 mm
2 in. were placed
longitudinally on the central part of the specimens on opposite sides. The unconfined compressive strength of the specimens was 40.7 MPa
5.9 ksi at the time of testing. Confinement was provided by two layers of CFRP attached by an epoxy adhesive, which is different from conventional confinement by steel as used in the authors’ original research. Testing was conducted by using a closed loop servocontrolled material testing system with a maximum capacity of 667 kN
150 kips. Since the envelope for CFRP confined concrete does not have the descending branch after a peak point as observed for conventionally reinforced cases, all specimens were initially loaded to 614 kN
138 kips at a rate of 62 kN
14 kips per minute to achieve sufficient plastic strain for a reasonable evaluation of the unloading/reloading paths.

There was a creep-hold of 108 min at 133 kN
30 kip load level for one of the specimens. At the load level of 614 kN
138 k, the specimen with a creep-hold was subjected to three complete unloading and reloading cycles at a rate of 124 kN
28 kips per minute, the next specimen had similar cycles but at a rate of 186 kN
42 kips per minute, and the last one was loaded monotonically to 614 kN
150 kips to establish the envelope curve.

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Analytical Sensitivity of Plastic Rotations in Beam-Column Elements

by Michael H. Scott

Abstract: Analytical sensitivity equations for the plastic rotation of beam-column finite elements are derived for reliability and optimization algorithms in structural engineering and for the assessment of plastic rotation sensitivity to uncertain design parameters and modeling assumptions. The plastic rotation is defined by elastic unloading of element forces in a basic system, which makes the corresponding sensitivity computations applicable to most material nonlinear beam-column formulations available in the literature. The analytical response sensitivity is verified by finite differences then applied to a first-order reliability analysis of a steel subassemblage where the performance function places a limit on plastic rotation.

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Controlling All Interstory Displacements in Highly Nonlinear Steel Buildings Using Optimal Viscous Damping

by T. L. Attard, M.ASCE

Abstract:
A gradient-based optimization algorithm is used to simultaneously control all interstory displacements in nonlinearly degrading steel buildings using optimal viscous dampers. Optimal damping ratios are computed in each mode of vibration such that the sum of the errors between the interstory displacements and the “just-yielded” performance objectives is minimized. A representative damping formulation is used to determine the sizes and locations of the damper devices. The members of the buildings are assumed to degrade smoothly according to a constitutive rule that was developed to model the behavior of kinematically strain-hardened materials. Numerical examples are used to demonstrate the ability of the algorithm to control potential damages in a 10-story building and also in an 8-story building responding at significant higher modes of vibration. It is found that the interstory displacements in the 10-story building are very adequately controlled. Although demands in the 8-story building are significantly reduced, some modes remain overdamped and not all performance levels are exactly met as some stories remain marginally damaged. Finally, the algorithm is applied in a 20-story benchmark building, and it is shown that the interstory displacements, postyield curvatures, and plastic damages are very adequately controlled.

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Classification and Seismic Safety Evaluation of Existing Reinforced Concrete Columns

by L. Zhu; K. J. Elwood; and T. Haukaas

Abstract:
This study contributes to the critical need for safety assessment tools for existing reinforced concrete structures. Of particular concern is the possibility of collapse due to shear failure followed by axial failure of columns supporting gravity loads. This is a potential threat to a number of existing buildings in seismically active regions. Due to unavoidable uncertainties, drift capacity predictions can only be made in a probabilistic manner. This is addressed by the development of probabilistic drift capacity models at two performance levels:
lateral strength degradation and axial load failure. First, a classification method is proposed to approximately distinguish between shear-dominated columns and flexure-dominated columns. Second, for each type of column, a probabilistic shear capacity model is developed by applying an existing Bayesian methodology to an experimental database. The focus of the presentation is on the physical insight gained from the model development. Third, a probabilistic model is developed for the drift capacity at axial load failure. Finally, the probabilistic drift capacity models are employed to develop fragility curves—with confidence bounds—that are utilized to assess the probability of failure implied by current seismic rehabilitation guidelines.

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Long-Term Behavior of Wood-Concrete Composite Floor/Deck Systems with Shear Key Connection Detail

by M. Fragiacomo; R. M. Gutkowski; J. Balogh; and R. S. Fast

Abstract:
The paper investigates the long-term behavior of wood-concrete composite beams with notched connection detail. The experimental program comprised the characterization of the component materials
wood, concrete, and connection detail and long-term tests on beam specimens. The beam specimens were monitored during the construction process, and for an overall period of 133 days after the application of the service load. The experimental results have then been extended to the entire service life of the structure using a
one-dimensional finite-element model. It was found that the increase in moisture content due to the bleeding of the fresh concrete is not an issue for the durability of the wood deck, and the type of construction
shored or unshored does not significantly affect the structural performance. The rheological phenomena experienced by the component materials lead to quite large deflections over the entire service life, whereas the variation in stress is not significant. If the limitation of the deflection is required for serviceability considerations, the use of concrete with reduced shrinkage and the precambering of the wood deck are to be recommended. A simplified approach based on closed form solutions for composite beams with smeared flexible connectors is finally proposed for the prediction of the long-term
behavior.

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Deterioration of Strength of RC Beams due to Corrosion and Its Influence on Beam Reliability

by Dimitri V. Val

Abstract: This paper examines the effect of corrosion of reinforcing steel on flexural and shear strength, and subsequently on reliability, of reinforced concrete beams. Two types of corrosion—general and pitting—are considered, with particular emphasis on the influence of pitting corrosion of stirrups on the performance of beams in shear. Variability of pitting corrosion along a beam is considered and the possibility of failure at a number of the beam cross sections is taken into account. Probabilities of failure are evaluated using Monte Carlo simulation. Uncertainties in material properties, geometry, loads, and corrosion modeling are taken into account. Results show that corrosion of stirrups, especially pitting corrosion, has a significant influence on the reliability of reinforced concrete beams.

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Confinement Model of Concrete with Externally Bonded FRP Jackets or Posttensioned FRP Shells

by Chris P. Pantelides, M.ASCE; and Zihan Yan

Abstract: A design-oriented confinement model for square and rectangular columns confined with bonded fiber-reinforced polymer
FRP jackets, and shape-modified square and rectangular sections confined with posttensioned FRP shells is developed. The proposed design model for FRP-confined concrete columns is based on the bilinear four-parameter formulation by Richard and Abbott. The axial compressive strength of FRP-confined concrete is obtained using concrete plasticity theory based on the five parameter Willam and Warnke model. The ultimate axial strain of FRP-confined concrete is obtained from a strain-based approach depending on either passive or active confinement; the ultimate axial strain is based on the concepts of secant concrete modulus and strain dependent stiffness established by Pantazopoulou and Mills. Comparisons of the proposed stress-strain model with uniaxial compression experiments for columns with bonded FRP jackets or posttensioned FRP shells, performed by the writers and other researchers, show satisfactory
agreement for the entire stress-strain curve.

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Static Strength of Thick-Walled CHS X-Joints Subjected to Brace Moment Loadings

by X. D. Qian; Y. S. Choo; J. Y. R. Liew; and J. Wardenier

Abstract:
This paper presents results from a systematic finite-element
FE study on the static strength of moment loaded thick-walled circular hollow section
CHS X-joints, and compares the results with CIDECT and ISO/CD 13819-2 recommendations. For thick-walled joints subjected to brace out-of-plane bending, the CIDECT formulation excludes the
dependency in the joint strength, which is different from the ISO equation and the present FE observations. The current study compares the different load paths mobilized in the X-joint under various brace loading conditions, through a detailed three-dimensional finite-element study. The numerical results reveal the significance of the joint geometric parameters and the tensile chord stress effect on the ultimate joint strength. Based on the present detailed study, a new chord stress function which incorporates the geometric dependency and the tensile chord stress effect is proposed.

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Determination of Composite Slab Strength Using a New Elemental Test Method

by Redzuan Abdullah and W. Samuel Easterling, F.ASCE

Abstract:
Composite slabs utilizing cold-formed profiled steel decks are commonly used for floor systems in steel framed buildings. The behavior and strength of composite slabs are normally controlled by the horizontal shear bond between the steel deck and the concrete. The strength of the horizontal shear bond depends on many factors and it is not possible to provide representative design values that can be applied to all slab conditions a priori. Thus, present design standards require that the design parameters be obtained from full-size bending tests, which are typically one or two deck panels wide and a single span. However, because these full-size tests can be expensive and time consuming, smaller size specimens, referred to as elemental tests, are desirable and have been the subject of a great deal of research. Details for a new elemental test method for composite slab specimens under bending are presented. Test results consisting of maximum applied load, end slips, and failure modes are presented and compared with the results of full-size specimens with similar end details, spans, etc. It is shown that the performance of the elemental test developed in this study is in good agreement with the performance of the full-size specimens. Application of test data to current design specifications is also presented.

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Vibration-Based Detection of Small-Scale Damage on a Bridge Deck

by Zhengjie Zhou; Leon D. Wegner; and Bruce F. Sparling

Abstract:
Vibration-based damage detection
VBDD methods use damage-induced changes to the dynamic properties of a structure to detect, locate, and sometimes quantify the extent of damage. This paper describes a laboratory-based experimental and finite element analysis study conducted to evaluate the ability of five different VBDD methods to detect and localize low levels of damage on the deck slab of a two-girder, simply supported bridge, with a focus on using a small number of sensors and only the fundamental mode of vibration. It is demonstrated that damage can be detected and localized longitudinally within a distance equivalent to the spacing between measurement points using data for only the fundamental mode shape before and after damage, defined by as few as five evenly spaced measurement points. The localization resolution declines by approximately 50% near supports. Increasing the number of measurement points improves the localization resolution of the techniques, although not always in proportion to the resulting decrease in measurement point spacing. Incorporating data from two additional modes was not found to significantly improve the localization performance.

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Possibilistic Approach for Damage Detection in Structural Health Monitoring

by E. Altunok; M. M. Reda Taha, M.ASCE; and T. J. Ross, F.ASCE

Abstract:
This article suggests the process of structural health monitoring
SHM in the context of a nonstatistical damage detection paradigm. We particularly focus on applying the theory of possibility to the damage detection problem. The basic idea behind the proposed approach is that the application of possibility theory does not require probabilistic knowledge or assumptions on the damage feature and thus encompasses aleatoric and epistemic types of uncertainties. The approach is not damage feature dependent and thus is generic for use in many SHM systems. Additionally, two new damage metrics are introduced. These metrics extract information concerning damage evidence from observations performed at unknown health states of structures. Damage detection with the aid of the proposed approach is demonstrated by means of a case study.

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Assessment of Improved Nonlinear Static Procedures in FEMA-440

by Sinan Akkar and Asli Metin

Abstract:
Nonlinear static procedures
NSPs presented in the FEMA-440 document are evaluated for nondegrading three- to nine-story reinforced concrete moment-resisting frame systems. Evaluations are based on peak single-degree-of-freedom displacement, peak roof, and interstory drifts estimations. A total of 78 soil site records and 24 buildings with fundamental periods varying between 0.3 s–1.3 s are used in 2,832 linear and nonlinear response-history analyses to derive the descriptive statistics. The moment magnitude of the ground motions varies between 5.7 and 7.6. All records are within 23 km of the causative fault representing near-fault ground motions with and without pulse signals. The statistics presented suggest that lateral loading patterns used in pushover analysis to idealize the building systems play a role in the accuracy of NSPs investigated. Both procedures yield fairly good deformation demand estimations on the median. Displacement coefficient method
DCM tends to overestimate the global deformation demands with respect to the capacity spectrum method
CSM. The conservative deformation demand estimations of DCM are correlated with the normalized lateral strength ratio, R. The CSM tends to overestimate the deformation demands for the increasing displacement ductility.

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Vertical Stiffness of Elastomeric and Lead–Rubber Seismic Isolation Bearings

by Gordon P. Warn; Andrew S. Whittaker, M.ASCE; and Michael C. Constantinou, M.ASCE

Abstract: An experimental study investigating the influence of lateral displacement on the vertical stiffness of elastomeric and lead–rubber seismic isolation bearings is summarized. Two identically constructed low-damping rubber and lead–rubber seismic isolation bearings were subjected to a series of tests with varying levels of combined lateral displacement and axial
compressive loading to study this relationship. The results of these tests showed the vertical stiffness decreases with increasing lateral displacement for each bearing tested. Additionally, the vertical stiffness data are used to evaluate four formulations for the estimation of the vertical stiffness as a function of the lateral displacement. From this comparison, two formulations, one based on the Koh–Kelly two-spring model and the other on a piecewise linear relationship, showed good agreement with the experimental data over the wide range of lateral displacements considered in this study.

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Testing of a Full-Scale Unreinforced Masonry Building Following Seismic Strengthening

by Franklin L. Moon; Tianyi Yi; Roberto T. Leon; and Lawrence F. Kahn

Abstract:
To investigate the effectiveness of several seismic strengthening techniques, a full-scale unreinforced masonry
URM structure was subjected to slowly applied lateral load reversals after the application of fiber reinforced plastic overlays, near surface mounted rods, and vertical posttensioning. Results showed that all techniques were effective for improving the seismic resistance of the previously tested URM building structure. Each system either increased the lateral in-plane strength and/or provided continuity of pier and spandrel elements over increased lateral displacements. In addition, the response of the test structure
overall height to base ratio of approximately one showed that global issues such as flange effects, the effects of overturning moment, and global rocking can be substantial and must be considered.

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Experimental Evaluation of a Large-Scale Buckling-Restrained Braced Frame

by Larry A. Fahnestock, P.E., M.ASCE; James M. Ricles, P.E., M.ASCE; and Richard Sause, P.E., M.ASCE

Abstract:
As buckling-restrained braced frames
BRBFs have been used increasingly in the United States, the need for knowledge about BRBF behavior has grown. In particular, large-scale experimental evaluations of BRBFs are necessary to demonstrate the seismic performance of the system. Although tests of buckling-restrained braces
BRBs have demonstrated their ability to withstand significant ductility demands, large-scale BRBF tests have exhibited poor performance at story drifts between 0.02 and 0.025 rad. These tests indicate that the large stiffness of the typical beam-column-brace connection detail leads to large flexural demands that cause undesirable failure modes. As part of a research program composed of numerical and experimental simulations, a large-scale BRBF with improved connection details was tested at the ATLSS Center, Lehigh University. During multiple earthquake simulations, which were conducted using a hybrid pseudodynamic testing method, the test frame sustained story drifts of close to 0.05 rad and BRB maximum ductility demands of
over 25 with minimal damage and no stiffness or strength degradation. The testing program demonstrated that a properly detailed BRBF can withstand severe seismic input and maintain its full load-carrying capacity.

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Seismic Response and Performance of Buckling-Restrained Braced Frames

by Larry A. Fahnestock, P.E., M.ASCE; Richard Sause, P.E., M.ASCE; and James M. Ricles, P.E., M.ASCE

Abstract:
As the use of buckling-restrained braced frames
BRBFs has increased in the United States, the need has grown for knowledge about member and system behavior under seismic loads and for implementing this knowledge into design provisions. In particular, methods for designing BRBFs and predicting seismic response require validation. To address this need, along with the need for experiments demonstrating system-level BRBF performance, a research program composed of numerical and large-scale experimental simulations was initiated at the ATLSS Center, Lehigh University. This paper describes the nonlinear dynamic analyses that were conducted as part of this research program. Numerical simulations of BRBF response were conducted using ground motion records scaled
to two seismic hazard levels. The performance of the prototype BRBF was acceptable and performance objectives were met in terms of structural damage. It is shown that the currently accepted deflection amplification factor underestimates mean inelastic lateral displacements under design-level earthquakes and the system overstrength factor may be unconservative. The current method for predicting BRB maximum ductility demands is also shown to be unconservative and a more rigorous method for predicting BRB maximum ductility demands is provided.

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PILE DESIGN AND CONSTRUCTION PRACTICE

Piles are columnar elements in a foundation which have the function of transferring load from the superstructure through weak compressible strata or through water, onto stiffer or more compact and less compressible soils or onto rock. They may be required to carry uplift loads when used to support tall structures subjected to overturning forces from winds or waves.

Piles used in marine structures are subjected to lateral loads from the impact of berthing ships and from waves. Combinations of vertical and horizontal loads are carried where piles are used to support retaining walls, bridge piers and abutments, and machinery foundations.

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THE MODIFIED COMPRESSION-FIED THEORY FOR REINFORCED CONCRETE ELEMENT SUBJECTED TO SHEAR

ACI Journal
Title no. 83-22
by Frank J. Vecchio and Michael P. Collins

Abstract
An analytical model is presented that is capable of predicing the load-deformation response of reinforced element subjected to in plane shear and normal stress. In the model, cracked concrete is treated as a new material with its own stress-strain characteristics. Equilibrium, compatibility, and stress-strain relationships are formulated in term of average stress and average strain. Consideration is also given to local stress conditional at crack location.

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HANDBOOK OF CIVIL ENGINEERING CALCULATION

This handbook presents a comprehensive collection of civil engineering calculation procedures useful to practicing civil engineers, surveyors, structural designers, drafters, candidates for professional engineering licenses, and students. Engineers in other disciplines—mechanical, electrical, chemical, environmental, etc.—will also find this handbook useful for making occasional calculations outside their normal field of specialty.

Each calculation procedure presented in this handbook gives numbered steps for performing the calculation, along with a numerical example illustrating the important concepts in the procedure. Many procedures include "Related Calculations" comments which expand the application of the computation method presented. All calculation procedures in this handbook use both the USCS (United States Customary System) and the SI (System International) for numerical units. Hence, the calculation procedures presented are useful to engineers throughout the world.

Major calculation procedures presented in this handbook include stress and strain, flexural analysis, deflection of beams, statically indeterminate structures, steel beams and olumns, riveted and welded connections, composite members, plate girders, load and resistance factor design method (LRFD) for structural steel design, plastic design of steel structures, reinforced and prestressed concrete engineering and design, surveying, route design, highway bridges, timber engineering, soil mechanics, fluid mechanics, pumps, piping, water supply and water treatment, wastewater treatment and disposal, hydro power, and engineering economics.

Each section of this handbook is designed to furnish comprehensive coverage of the topics in it. Where there are major subtopics within a section, the section is divided into parts to permit in-depth coverage of each subtopic. Civil engineers design buildings, bridges, highways, airports, water supply, sewage treatment, and a variety of other key structures and facilities throughout the world. Because of the importance of such structures and facilities to the civilized world, civil engineers have long needed a handbook which would simplify and speed their daily design calculations. This handbook provides an answer to that need.

While there are computer programs that help the civil engineer with a variety of engineering calculations, such programs are highly specialized and do not have the breadth of coverage this handbook provides. Further, such computer programs are usually expensive. Because of their high cost, these computer programs can be justified only when a civil engineer makes a number of repetitive calculations on almost a daily basis. In contrast, this handbook can be used in the office, field, drafting room, or laboratory. It provides industry-wide coverage in a convenient and affordable package. As such, this handbook fills a long-existing need felt by civil engineers worldwide.

In contrast, civil engineers using civil-engineering computer programs often find dataentry time requirements are excessive for quick one-off-type calculations. When one-offtype calculations are needed, most civil engineers today turn to their electronic calculator, desktop or laptop computer and perform the necessary steps to obtain the solution desired. But where repetitive calculations are required, a purchased computer program will save time and energy in the usual medium-size or large civil-engineering design office. Small civil-engineering offices generally resort to manual calculation for even repetitive procedures because the investment for one or more major calculation programs is difficult to justify in economic terms.

Even when purchased computer programs are extensively used, careful civil engineers still insist on manually checking results on a random basis to be certain the program is accurate. This checking can be speeded by any of the calculation procedures given in this handbook. Many civil engineers remark to the author that they feel safer, knowing they have manually verified the computer results on a spot-check basis. With liability for civilengineering designs extending beyond the lifetime of the designer, every civil engineer seeks the "security blanket" provided by manual verification of the results furnished by a computer program run on a desktop, laptop, or workstation computer. This handbook gives the tools needed for manual verification of some 2,000 civil-engineering calculation procedures.

Each section in this handbook is written by one or more experienced professional engineers who is a specialist in the field covered. The contributors draw on their wide experience in their field to give each calculation procedure an in-depth coverage of its topic. So the person using the procedure gets step-by-step instructions for making the calculation plus background information on the subject which is the topic of the procedure. And since the handbook is designed for worldwide use, both earlier, and more modern topics, are covered. For example, the handbook includes concise coverage of riveted girders, columns, and connections. While today's civil engineer may say that riveted construction is a method long past its prime, there are millions of existing structures worldwide that were built using rivets. So when a civil engineer is called on to expand, rehabilitate, or tear down such a structure, he or she must be able to analyze the riveted portions of the structure. This handbook provides that capability in a convenient and concise form.

In the realm of modern design techniques, the load and resistance factor method (LRFD) is covered with more than ten calculation procedures showing its use in various design situations. The LRFD method is ultimately expected to replace the well-known and widely used allowable stress design (ASD) method for structural steel building frameworks. In today's design world many civil engineers are learning the advantages of the LRFD method and growing to prefer it over the ASD method.

Also included in this handbook is a comprehensive section titled "How to Use This Handbook." It details the variety of ways a civil engineer can use this handbook in his or her daily engineering work. Included as part of this section are steps showing the civil engineer how to construct a private list of SI conversion factors for the specific work the engineer specializes in.

The step-by-step practical and applied calculation procedures in this handbook are arranged so they can be followed by anyone with an engineering or scientific background. Each worked-out procedure presents fully explained and illustrated steps for solving similar problems in civil-engineering design, research, field, academic, or license-examination situations. For any applied problem, all the civil engineer need do is place his or her calculation sheets alongside this handbook and follow the step-by-step procedure line for line to obtain the desired solution for the actual real-life problem. By following the calculation procedures in this handbook, the civil engineer, scientist, or technician will obtain accurate results in minimum time with least effort. And the approaches and solutions presented are modern throughout.

The editor hopes this handbook is helpful to civil engineers worldwide. If the handbook user finds procedures which belong in the book but have been left out, he urges the engineer to send the title of the procedure to him, in care of the publisher. If the procedure is useful, the editor will ask for the entire text. And if the text is publishable, the editor will include the calculation procedure in the next edition of the handbook. Full credit will be given to the person sending the procedure to the editor. And if users find any errors in the handbook, the editor will be grateful for having these called to his attention. Such errors will be corrected in the next printing of the handbook. In closing, the editor hopes that civil engineers worldwide find this handbook helpful in their daily work.

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CONCRETE FORMWORK SYSTEM

Formwork development has paralleled the growth of concrete construction throughout the 20th century. In the last several decades formwork technology has become increasingly important in reducing overall costs, since the structural frame constitutes a large portion of the cost of a formwork system.

This book has three objectives. The first is to provide technical descriptions and evaluations of ten formwork systems that are currently used in concrete construction. The second is to serve as a tool to assist contractors in selecting the optimal formwork system. The third is to present the design criteria for conventional formwork for slabs and walls using the stress and the stress modification factors provided by the National Design Specifications (NDS) and the American Plywood Association (APA).

Following a comprehensive introductory chapter, five types of formwork systems for concrete slabs are presented in chapters 2–5. These are conventional wood forms, conventional metal forms, flying forms, the column-mounted shoring system, and tunnel forms. The last four chapters describe five types of formwork systems for concrete columns and walls: conventional wood forms, ganged forms, jump forms, slip forms, and self-raising forms. Particular consideration is given to topics such as system components, typical work cycles, productivity, and the advantages and disadvantages associated with the use of various systems.

The selection of a formwork system is a critical decision with very serious implications. Due consideration must be given to such factors as the system’s productivity, safety, durability, and many other variables that may be specific to the site or job at hand. Chapters 5 and 9 provide a comparative analysis of forming systems for horizontal and vertical concrete work to facilitate the selection of the optimal forming system.

Existing formwork design literature is inconsistent with the design criteria for wood provided by the NDS and the APA. Chapters 3 and 7 provide a systematic approach for formwork design using the criteria of the American Concrete Institute committee 347-94, the NDS, and the APA. For international readers, metric conversion is provided in the Appendix.

This book is directed mainly toward construction management, construction engineering and management students, and concrete contractors. It may also serve as a useful text for a graduate course on concrete formwork, and should be useful for practicing engineers, architects,
and researchers.

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BRIDGE ENGINEERING SUBSTRUCTURE DESIGN

The Bridge Engineering Handbook is a unique, comprehensive, and the state-of-the-art reference work and resource book covering the major areas of bridge engineering with the theme “bridge to the 21st century.” It has been written with practicing bridge and structural engineers in mind. The ideal readers will be M.S.-level structural and bridge engineers with a need for a single reference source to keep abreast of new developments and the state-of-the-practice, as well as to review standard practices.

The areas of bridge engineering include planning, analysis and design, construction, maintenance, and rehabilitation. To provide engineers a well-organized and user-friendly, easy to follow resource, the Handbook is divided into four volumes: I, Superstructure Design II, Substructure Design III, Seismic Design, and IV, Construction and Maintenance.

Volume II: Substructure Design addresses the various substructure components: bearings, piers and columns, towers, abutments and retaining structures, geotechnical considerations, footing and foundations, vessel collisions, and bridge hydraulics.

The Handbook stresses professional applications and practical solutions. Emphasis has been placed on ready-to-use materials. It contains many formulas and tables that give immediate answers to questions arising from practical work. It describes the basic concepts and assumptions omitting the derivations of formulas and theories. It covers traditional and new, innovative practices. An overview of the structure, organization, and content of the book can be seen by examining the table of contents presented at the beginning of the book while an in-depth view of a particular subject can be seen by examining the individual table of contents preceding each chapter. References at the end of each chapter can be consulted for more detailed studies.

The chapters have been written by many internationally known authors from different countries covering bridge engineering practices and research and development in North America, Europe, and the Pacific Rim. This Handbook may provide a glimpse of a rapid global economy trend in recent years toward international outsourcing of practice and competition in all dimensions of engineering. In general, the Handbook is aimed toward the needs of practicing engineers, but materials may be reorganized to accommodate undergraduate and graduate level bridge courses. The book may also be used as a survey of the practice of bridge engineering around the world.

The authors acknowledge with thanks the comments, suggestions, and recommendations during the development of the Handbook, by Fritz Leonhardt, Professor Emeritus, Stuttgart University, Germany; Shouji Toma, Professor, Horrai-Gakuen University, Japan; Gerard F. Fox, Consulting Engineer; Jackson L. Kurkee, Consulting Engineer; Michael J. Abrahams, Senior Vice President; Parsons Brinckerhoff Quade & Douglas, Inc.; Ben C. Gerwick Jr., Professor Emeritus, University of California at Berkeley; Gregory F. Fenves, Professor, University of California at Berkeley; John M. Kulicki, President and Chief Engineer, Modjeski and Masters; James Chai, Supervising Transportation Engineer, California Department of Transportation; Jinron Wang, Senior Bridge Engineer, California Department of Transportation; and David W. Liu, Principal, Imbsen & Associates, Inc.

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BASIC TOOLS OF REINFORCED CONCRETE BEAM DESIGN

ACI Journal
Title no. 82-4
by Peter Marti

Abstract
The application of consistent equilibrium and ultimate strength consideration to the design and detailing of reinforced concrete beams is described. Basic tools insclude struts and tie, nodes, fans, and arches. Comparisons with experiments on a shearwall coupling beam and on a deep beam and three design examples illustrate the practical application of these tools.

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STRUCTURAL DETAILS IN CONCRETE

by M.Y.H. Bangash

Contents :
I. General Requirements for Structural Detailing in Concrete
II. Reinforced Concrete Beams and Slabs
III. Stairs and Staircases
IV. Columns, Frames and Wall
V. Prestress Concrete
VI. Composite Construction, Precast Concrete Elements, Joint, and Connection
VII. Concrete Foundation and Earth-Retaining Structures
VIII. Special Stuctures

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CORRELATION OF SITE CONDITION - BUILDINGS DAMAGES – AND GROUND RUPTURE OF THE 27 MAY 2006 YOGYAKARTA EARTHQUAKE – CENTER JAVA

The 27 May 2006 earthquake produced a strike-slip ground rupture about ± 80 Km. long. It stretches along general N 220-245E direction from Desa Parangtritis – Distric Kretek- Kabupaten Bantul to Desa Prajinan, Distric Josonalan, Kabupaten Klaten. The sense of horizontal movement is left-lateral. Its epicenter lies within “the District Saden area” (?), Kabupaten Bantul and registered a magnitude of 6.3 (Ms) on the open ended Richter scale. The ground rupture was responsible for part of the damage inflicted by the earthquake. Hardest hit by rupturing are the Kampung Sengir, Piyungan, Srimartani, Derjo, Pathuk, Taji, Prambanan District. Many roads and one bridge were also cracked by the ground rupturing. Vibration triggered landslides and liquefaction and settling. Vibration was widely felt and its intensity varied with local ground conditions. Landslides affected Sengir. Liquefaction and settling damaged mostly the river deposits (flood plain) areas in and near Taji, Prajinan and Srimartani.

Post earthquake study of the ground ruptures provides additional insights into the possibilities that might be expected in case the Melange Cretaceous-Tertiary Fault (Kertapati, 1999) and Opak Fault or other faults move again. Future activities of similar magnitudes along the ground rupture will most probably follow the same trace. Structural controls that affected rupture propagation and arrest might provide us clues as to the size of the next earthquake and enable us to identify sites where high frequency energy inducing strong ground-motion might be expected along the trace.

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New Attenuation Relation for Earthquake Ground Motions in Indonesia Considering Deep Source Events

by Rizkita Parithusta
(Department of Earth and Planetary Sciences Institute of Seismology and Volcanology — Kyushu University, and Indonesia Center for Earthquake Engineering)
Seminar dan Pameran HAKI 2007 - “KONSTRUKSI TAHAN GEMPA DI INDONESIA”

Abstract
Attenuation relation of the peak horizontal ground accelerations for Indonesia region is developed. The database is compiled for earthquakes with moment magnitudes Mw ≥ 5 that occurs during 1971 – 2007, which consists of horizontal peak ground accelerations and their 5 percent damped response spectra; the accelerograms are recorded on different site conditions classified as rock, hard and soft soils. Earthquake hypocenters with depths up to 150 km are used to attune the equation relevant to subduction, which are the most common earthquake events in Indonesia. The effects of the local site conditions and depth on the attenuation relation are considered simultaneously with the distance and magnitude using a two-stage regression procedure to separate the distance dependence from that of the magnitude.

An iterative partial regression algorithm is proposed to overcome the singularity of the resulting normal equations. It can be observed that the peak ground motions increase with depth for the same magnitude and distance. Considering the soil conditions, it is noticeable that the station coefficients correspond to the soil-type classification varies widely. For the peak ground accelerations, the station coefficients are closely related to the general soil-type classification; while the peak ground velocity have strong relationship with the soil-type classification.

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Seismic Chart In Performance-Based Earthquake Engineering

by Sindur P. Mangkoesoebroto
(Indonesia Center for Earthquake Engineering and Institute of Technology Bandung, http://www.icfee.info, e-mail itbpauir@bdg.centrin.net.id.)
Seminar dan Pameran HAKI 2007 - “KONSTRUKSI TAHAN GEMPA DI INDONESIA”

Abtract
A seismic chart as design aid for simple structures is proposed. It is suitable to be used in the environment of the Performance-Based Earthquake Engineering together with the Non-linear Static Procedure (NSP) or pushover analysis. The chart utilizes the inelastic response spectra of 10% kinematic hardening SDOF system. The performance parameters to include strength, hysteretic energy and damage, as function of numbers of independent variables such as the intensity & duration of the input motions, site characteristic, ductility, with constraint on displacement, are discussed. The random variables involved and their uncertainties can be taken into account explicitly, enabling simple incorporation of the information on the Seismic Hazard Analysis, when available. Comparison with the experimental data confirms the prediction.

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West Sumatra Earthquake, 6 March 2007, Structural Damage Report

by Teddy Boen
(Senior Advisor WSSI (World Seismic Safety Initiative)
Seminar dan Pameran HAKI 2007 - “KONSTRUKSI TAHAN GEMPA DI INDONESIA”

INTRODUCTION
On Thursday, March 6, 2007 at 10:49 AM, Singkarak Lake and its surrounding areas were shaken by a moderate earthquake while most people were working and children were studying at schools. According to USGS (United States Geological Survey), the epicenter of this earthquake is at 0.536°S, 100.498°E with 30 km depth and the magnitude was 6.3 Mw. The epicenter is 49 km from Padang, and 159 km from Pekanbaru.

The damaged places visited are Solok District, Tanah Datar District, and Agam District. The damage at those districts was scattered. The most damaged area in Solok is at Sumani Village (Singkarak Sub-District); in Tanah Datar is at Batipuh Village (Rambatan Sub-District) and Padang Panjang; in Agam is at Sungai Tanang Village (Banuhampu Sub-District) and Bukit Tinggi. There were no places / villages which were heavily damaged. The earthquake impact was not as big as exposed by newspapers and electronic media. The number of wounded casualties were also not as many as was the case during the Yogyakarta May 27, 2006 earthquake. The health care facilities in Solok did not experience an influx of wounded casualties. There was no mass emergency situation at all. The hastily built tents outside the hospital were not utilized.

Buildings that were damaged or collapsed during the March 6, 2007 West Sumatra earthquake were mostly masonry non engineered constructions, consisting of one or two stories houses, shop houses, religious and school buildings. The damaged buildings are scattered. The main cause of the damage buildings are poor quality of construction materials and poor workmanship.

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Bridge Engineering Construction and Maintenance

The Bridge Engineering Handbook is a unique, comprehensive, and the state-of-the-art reference work and resource book covering the major areas of bridge engineering with the theme “ ridge to the Twenty-First Century.” It has been written with practicing bridge and structural engineers in mind. The ideal reader will be an M.S.-level structural and bridge engineer with a need for a single reference source to keep abreast of new development and the state-of-the-practice, as well as review standard practices.

The areas of bridge engineering include planning, analysis and design, construction, maintenance and rehabilitation. To provide engineers a well organized and user-friendly, easy to follow resource, the handbook is divided and printed into four Volumes: I Superstructure Design, II Substructure Design, III Seismic Design, and IV Construction and Maintenance.

Volume IV Construction and Maintenance contains constructions of steel and concrete bridges, substructures of major overwater bridges, construction inspections, construction control for cable-stayed bridges, maintenance inspection and rating, strengthening and rehabilitation.

The handbook stresses professional applications and practical solutions. Emphasis has been placed on ready-to-use materials. It contains many formulas and tables that give immediate answers to questions arising from practical works. It describes the basic concepts and assumptions omitting the derivations of formulas and theories. It covers traditional and new, innovative practices. An overview of the structure, organization, and content of the book can be seen by examining the table of contents presented at the beginning of the volume while an in-depth view of a particular subject can be seen by examining the individual table of contents preceding each chapter. References at the end of each chapter can be consulted for more detailed studies.

The chapters have been written by many internationally known authors in different countries covering bridge engineering practices, and research and development in North America, Europe, and Pacific Rim countries. This handbook may provide a glimpse of rapid global economy trend in recent years toward international outsourcing of practice and competition of all dimensions of engineering. In general, the handbook is aimed at the needs of practicing engineers, but materials may be re-organized to accommodate several bridge courses at the undergraduate and graduate levels. The book may also be used as a survey of the practice of bridge engineering around the world.

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AASHTO Standard Specifications For Highway Bridge 16th

The structural design standards used by state bridge engineers, engineering colleges and universities, and practicing engineers worldwide. Customary U.S. Units. Loose-leaf with three ring binder. Replaces the 15th Edition and Interim Specifications-Bridges-1993, 9400 and 1995.

Major changes and revisions to this edition are as follows :

1. The Interim Specification of 1993, 1994, 1995, and 1996 have been adopted and are included.
2. Entire Division I-A, Seismic Design was revised.
3. Section 17, Soil-Reinforced Concrete Structure Interaction System, of Division I was revised.
4. Section 26, Metal Culverts, of Division II was revised
5. Section 27, Concrete Culvert, of Division II was revised
6. Section 29, Embedment Anchors, was added to Division II.
   

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Bridge Engineering Construction and Maintenance

This chapter addresses some of the principles and practices applicable to the construction of mediumand long-span steel bridges — structures of such size and complexity that construction engineering becomes an important or even the governing factor in the successful fabrication and erection of the superstructure steelwork.

We begin with an explanation of the fundamental nature of construction engineering, then go on to explain some of the challenges and obstacles involved. The basic considerations of cambering are explained. Two general approaches to the fabrication and erection of bridge steelwork are described, with examples from experience with arch bridges, suspension bridges, and cable-stayed bridges.

The problem of erection-strength adequacy of trusswork under erection is considered, and a method of appraisal offered that is believed to be superior to the standard working-stress procedure. Typical problems with respect to construction procedure drawings, specifications, and practices are reviewed, and methods for improvement suggested. The need for comprehensive bridge erection-engineering specifications, and for standard conditions for contracting, is set forth, and the design-andconstruct contracting procedure is described.

Finally, we take a view ahead, to the future prospects for effective construction engineering in the U.S. The chapter also contains a large number of illustrations showing a variety of erection methods for several types of major steel bridges.

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DESIGN OF CONCRETE STRUCTURES

The thirteenth edition of Design of Concrete Structures has the same dual objectives as the previous work : first to establish a firm understanding of the behavior of structural concrete, then to develop proficiency in the methods used in current design practice. The text has been updated in accordance with the provision of the 2002 American Concrete Institute (ACI) Building Code.

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part 1
part 2
part 3
part 4

SEISMIC DESIGN ASPECTS FOR PRECAST CONCRETE FRAMES

Strong – Connection Systems

Ideal location for critical section of a plastic hinges:

1. Beam – to – column connection: not less than a distance hb (beam depth) from the connection.

2. Column – to – beam connection: at anywhere within the beam length, between column faces.

3. Beam – to – beam connection: not less than a distance hb (beam depth) from the connection.

4. Column – to – column connection: at anywhere within the beam length, between column faces

5. Column – to – footing connection: not less than a distance hc (column width in the direction considered) from the connection.

Location for ductile connection:

1. In beams – at any location. But it is better to locate it as close as possible to the columns

2. At column bases – to complete mechanism

Requirements for Special Moment Frames with Strong Connections

• Shall satisfy all requirements for SRPMK

• Segments between locations where flexural yielding is intended to occur follow bernoulli princpl (min 4 times h)

• Design strength of the strong connection fSn shall be not less than Se

• Primary long rebars shall be made continuous across connections and shall be developed outside both the strong connection and the plastic hinge region.

• Column-to-column connections shall have design strength fSn not less than 1.4Se, the design flexural strength fMn not less than 0.4 times the maximum probable flexural strength Mpr for the column within the story height, and the design shear strength fVn of the connection shall be not less than that determined by Mpr .

SRPM with ductile connection constructed using precast concrete shall satisfy the following requirements and other requirement for SRPMK:

• The nominal shear strength for connections, Vn , shall be greater than or equal to 2Ve, and

• Mechanical splices of beam reinforcement shall be located not closer than h/2 from the joint face

Emulation Design

• Based on SNI Concrete code chapter 23.2.1.5:

1. The system will have strength and toughness equal to or exceeding those provided by a comparable monolithic reinforced concrete structure

• Procedures

1. Design the structure as if it is to be constructed by monolithic cast in place reinforced concrete methods.

2. Disassemble the structure “on paper” into appropriate sizes and shapes to meet the following criteria, i.e. suitable for plant fabrication, capable of being transported and can be erected by the available cranes.

3. Design the connection:

· connect rebars between the precast elements by mechanical splices, welding the rebars, or by grouting the conduit or sleeves with high-strength, non shrink grout

· connect the precast concrete elements using a high-strength, non shrink grout in the interfaces or by placing conventional concrete in the spaces between the precast elements.

Emulation Details

• Reinforcing steel splicing is accomplished in the same manner as in cast – in – place – concrete by:

1. Lapping

2. Welding

3. Joining with mechanical splices

• SNI Specification

1. Connect the reinforcing bars by mechanical splices, welding, grouting or sleeves with high-strength and non-shrink grout.

2. Both welded and mechanical splices must achieve strengths of at least 125 percent of rebar yield strength, fy.

3. For lapped splices refers to chapter 14 of SNI Concrete Code

4. The bar size determines the size of connection device

5. Staging of the erection should be considered in design

CONNECTION MADE BY GROUTING OF PRECAST CONCRETE COMPONENTS

• When cement-based grouts are used they should be high strength and non-shrink. The minimum grout compressive strength should be 10 MPa greater than that of the surrounding concrete.

• For all grouting situations, extreme thoroughness with respect to cleanliness and the following of manufacturer’s instructions is required.

• When bars are grouted in horizontal or inclined holes, bar locaters should be used to keep the bars in the center of the holes.

• Designers should communicate to contractors at tender stage all the specialized requirements for the grouting operations, including the need for experienced operators and a satisfactory quality assurance programme.

• The grout volume method should be used to determine whether or not the units have been fully grouted.

• Before compressed air is used to blow out dust from holes, it should be tested for oil contamination.

Preferable Behaviour of Precast System

• Behaviour of Precast System @ Behaviour of Monolithic System

• Structural Element Yield Under Bending Type of Failure

• Beam Yield First

• Slip And Shear Mechanisms Do Not Dominate the Behaviour

• Shows Stable Hysteretic Behaviour

Example of Strong Beam to Column Connection

Example of Strong Column to Column Connection