The New York State Department of Transportation has been using advanced composite materials in several bridge applications for past three years.  These include replacement of a deteriorated concrete superstructure with an FRP superstructure, FRP bridge decks, and strengthening of beams and columns.  This presentation will focus on technical tasks related to planning, design, and construction of these bridges, followed by a summary of other on-going structures related research activities at the Transportation research and Development Bureau.

Structural slurry walls (diaphragm walls) have been used with increasing frequency in the United States since their introduction in the 1960’s. The design and construction developments of structural slurry walls will be presented in this seminar. Major improvements have been made in the method of analysis of the wall/support system, in the development of wall reinforcing, and in the development of better tools for execution of the work. Case histories will be used to illustrate the state-of-the-art design and construction techniques.

This presentation on the twin 451.9m (1483 ft.) tall, 88 story towers in Kuala Lumpur, Malaysia, will highlight key design and construction features of the unusual foundations of these buildings, currently the tallest in the world.

Irregular bedrock required extensive pre-design, analysis and construction attention.  Elaborate borings and probes established profiles and soil characteristics.  Detailed 3-D finite element models set the variations in barrette lengths, up to 130 m (426 ft.) deep, to avoid differential settlement without bearing on rock.  Skin grouting, cavity grouting and slump zone grouting further reduced settlements.  Other foundation features include massive concrete mats, perimeter slurry walls 1 km (0.6 mi.) long and 20 m (66 ft.) deep, and a pressure relief system under low-rise portions of the project.

The superstructure design considered wind effects on load and occupant comfort.  A high-strength concrete cast-in-place core, perimeter columns and ring beams economically carry vertical loads and provide lateral load stiffness with high inherent damping for occupant comfort. Steel beams on metal deck slabs provide economy, fast erection and adaptability to future changes in openings and loads.  The project also features a unique Skybridge spanning 58.4 m (190 ft.) between towers at levels 41 and 42, and a tall pinnacle of structural stainless steel crowning each tower.

 The purpose of this research is to provide the means to envision construction management in a multi - dimensional matrix, and to establish a global environment for efficient exchange of information. This collaborative environment, named NDCON, (“N-Dimensional CONstruction Management Information System”), is an information system using a 3D CAD Model as the “Origin” to provide Quantity Information for Cost Estimating System. By sharing the information which the Scheduling, Procurement and Accounting System need from Cost Estimating, a fully customized Object-Oriented construction management Database Application is developed to extend 3D to a nD system, with the purpose of not only managing the construction information from a Multi-Dimensional point of view but also visualizing the construction process.

Accuracy of boundary value predictions depends to a large extent on the accuracy of the constitutive models used to describe the stress-strain behavior of the materials involved. A general rate-independent, elasto-plastic framework of modeling the stress-strain behavior of soils is presented. Some specific constitutive models for soils and their applications to static and dynamic boundary value analyses are presented. These models collectively address various aspects of the stress-strain behavior of soils, including anisotropy, dilation and compaction, and cyclic liquefaction. The bounding surface concepts are used to model the plastic behavior of soils for stress states inside the yield surface.

Dr. Anandarajah is currently a Professor of Civil Engineering at the Johns Hopkins University. His research area of specialization is geomechanics. Dr. Anandarajah has published extensively in the areas of constitutive modeling, numerical modeling, micromechanics, and fundamentals of soil behavior. Dr. Anandarajah is currently an Associate Editor of the Journal of Engineering Mechanics of ASCE. He is also the Chair of the Inelastic Behavior Committee of the Engineering Mechanics Division of ASCE, and a member of the Properties of Materials Committee of the Engineering Mechanics Division of ASCE.

The objectives of wind engineering are to estimate wind loads and their effects on structures, with a view to: (1) developing design procedures ensuring that structures are both safe and economical, (2) accurately predicting losses due to hurricanes and other strong winds. In this talk we review:  case studies illustrating gross design errors that have been and continue to be made by even first rate structural engineers; aerodynamic measurement techniques; computational  advances that markedly reduce the possibility that gross errors will be made, and allow representations of wind effects that are far more accurate than conventional code representations; and methods for developing reliable and risk-consistent designs by accounting for both aleatory and epistemic uncertainties.

In order to rationalize structural maintenance, this study focuses on vibration characteristics as indices to detect damage and addresses
develops advanced vibration measurement system and damage detection method based on changes in vibration characteristics. First of all, vibration measurement system using Laser Doppler Vibrometer, which can scan the objective structural surface, is developed and an identification method from laser ambient vibration measurement is proposed. Next, a damage detection method which calculates mass and stiffness changes in reverse based on changes in mode shapes, is also constructed. These methods show their validity experimentally through vibration measurement for a steel plate before/after damage. Furthermore, to be applied for real civil structures which possess low laser reflection, the laser vibration measurement system is advanced with adding a function which can automatically search the maximum points of laser reflection. By means of this system, vibration measurement on a reinforced concrete deck is carried out and its local mode shapes are identified.

Hysteretic behavior of a bar under repeated axial loading is to be discussed.  Basic equations are first derived in a closed form through an elastic-plastic type of analysis in conformity with one-dimensional idealization.  They are adequate to determine the load-deformation characteristics of a centrally loaded pin-ended bar.  This formulation is generalized to include the effect of repeated changes in temperature.   The theory is also extended to accommodate the effects of load eccentricity and rotational constraint at the bar ends. Diagrammatical representation of state variation provides a better understanding of plastic hysteretic behavior.  The theory is capable of describing an overall elastic-plastic behavior of a structural brace or truss member, under any history of tension and/or compression or of corresponding displacements or temperature variation.  Effects of large deflection and of changes in bar dimensions are also discussed. Numerical examples are presented to demonstrate the application of the basic equations.  Comparison is made of the theoretical prediction with experimental observations on mild steel bars under combination of tension and compression.  Tests are also made to examine deteriorating and fatigue phenomena on structural angles subjected to repeated severe loading.  Mention is made of finite element simulation against the experimental observation.