Editor’s Note

Before describing the articles, papers, and so on that are included in the November 2005 issue of the Practice Periodical, we wish to mention that this issue happens to be an anniversary issue. It has been $10\text{years}$ since the Practice Periodical on Structural Design and Construction came into being. Individuals who were instrumental in creating this publication helped to prepare an editorial that traces the history and current status of the Practice Periodical. This interesting editorial is included in this issue. And now for the rest of the contents.

The first paper should be of interest to most building designers, that is, engineers and architects. It is entitled “Electronically Enhanced–Traditional Structural Steel Beam Design Using Electronic Design Charts” and was prepared by Professor Souhail Elhouar of Bradley University, Peoria, Ill. It describes a practical tool that was developed by using Microsoft Excel (2002) to allow a structural designer to generate project-specific unbraced beam design charts similar to the ones that can be found in Part 5 of the AISC Steel Design Manual. These charts can be developed for a user-specified material, unbraced length, design moment, bending coefficient, $C_b$ , and a range of nominal depths. Readers are invited to use this design tool and provide the author and us with comments about its effectiveness.

The second paper deals with highway bridges and is entitled “Partial Continuity in Bridge Girders with Jointless Decks.” The authors are Ayman M. Okeil of Louisiana State University, Baton Rouge, La., and Adel ElSafty of Florida State University, Panama City, Fla. Many bridges are constructed in groups of simple spans. This construction system requires the use of deck (expansion) joints over piers, which in turn leads to costly maintenance and repair. The construction of bridges without expansion joints eliminates a significant portion of the direct and indirect costs associated with expansion joints. This paper proposes a method for the flexural analysis of bridges with jointless decks. The proposed method is used in a demonstration–example parametric study to investigate the effects of span length ratios, link slab thickness, and girder axial stiffness on the behavior of a two-span jointless bridge. Two types of widely used support configurations are considered, and expressions for the tension force in link slabs are derived. The method is promising and should be of interest to bridge design engineers.

The third paper in this issue deals with “Optimum Layout of Buildings Subjected to Geometric Constraints.” It was prepared by F. Guerra, who is a structural engineer with the Panama Canal Authority, Balboa, Panama. In the method proposed by the author, when a preliminary layout of a building is given, vertical members are relocated on the basis of an optimization technique to obtain the best structural building performance when subjected to lateral loads under specified constraints. The analysis is based on a nonlinear programming algorithm; and relocatable, vertical building elements are chosen by using a sensitivity analysis. The optimization is done for static constraints. The analysis is carried out in conjunction with a finite-element model of the building. The author presents several examples to illustrate the use of the method, which appears to be very promising and should be of interest to building designers.

The fourth paper is entitled “Hurricane Wind Shelter Retrofit Room Guidelines for Existing Houses.” It was prepared by Nur Yazdani of Florida A&M University–Florida State University College of Engineering, Tallahassee, Fla.; Tanya Townsend of the South Florida Water Management District, West Palm Beach, Fla.; and Danny Kilcollins of the Division of Emergency Management, Florida Department of Community Affairs, Tallahassee, Fla. The objective of the study on which this paper is based was to develop design and construction techniques for an in-home hurricane room shelter, which is an alternative to the Federal Emergency Management Agency (FEMA) tornado-safe room. Such a room would be able to withstand hurricane or tornado wind speed loadings up to $225\mathrm{km}∕\mathrm{h}$ $\left(140\mathrm{mph}\right)$ and associated windborne debris impacts. Structural calculations that are based on known material strengths, design wind pressures, and missile impact capacities from previous research were used. The retrofitting is achieved through upgrading existing walls and roofs of typical small interior rooms with plywood sheets, steel plates, anchor bolts, hurricane straps, and debris impact-resistant doors. The in-house shelter, which can also be constructed as a stand-alone unit, is expected to offer significant occupant protection and reduce the demand on public shelters in the event of a mid-Category-4 hurricane. The total cost of a hurricane room is $3,000 (2004, Florida) for labor and materials, a significant saving over the published cost of a FEMA tornado-safe room.

The fifth paper deals with construction issues and is entitled “Constructing a Physical Model of the Piura River.” It was prepared by Jessica Carolina Garcia Ruesta and J. Reyes Salazar of the University of Piura and Cliff J. Schexnayder of the Del E. Webb School of Construction, Arizona State University, Tempe, Ariz. The El Niño phenomena affect a great portion of South America, especially the northern coast of Peru where the River Piura flows into the Pacific Ocean. During the mega El Niño events of 1983 and 1998, large land areas suffered serious flood damage. To study the behavior of the river locally with the object of finding ways to mitigate future flooding, a model of the river was constructed. This article describes the design and construction of a physical model for studying the flow of the Piura River. The model was commissioned as a direct result of the flood damage that occurred during the 1998 El Niño. The river model is located at the University of Piura.

The sixth paper deals with important construction issues and is entitled “Assessing and Managing the Potential Environmental Risks of Construction Projects.” It was prepared by S. Dione, J. Y. Ruwanpura, and J. P. A. Hettiaratchi, all of the University of Calgary, Calgary, Alta., Canada. The authors state that although policymakers make key decisions regarding economic development, it is the engineers who are central to the implementation of such policies and therefore carry a certain risk. With the realization that economic development and local environment are interlinked, engineers are well advised to ensure avoidance of adverse impacts on society and the environment by adopting better practices during the design and implementation of construction projects. The objective of this paper is to present a framework so that engineers and constructors can identify potential environmental risks early in a project’s life, thus allowing for the development of plans to mitigate their impact. This paper also discusses currently available options for environmental-type insurance and contractual liability indemnity clauses in Canada.

The seventh paper is construction-safety-oriented and is entitled “Evaluation of Rumble Strips and Police Presence as Speed Control Measures in Highway Work Zones.” It was prepared by Wesley C. Zech of Auburn University, Alabama, Satish Mohan of SUNY Buffalo, New York, and Jacek Dmochowski of the University of North Carolina, Charlotte, N.C. This paper presents the results of a field study conducted on western New York State highway work zones to evaluate two types of speed control devices, that is, rumble strips and police presence in combination with rumble strips. The study included speed measurements of approximately 554,400 vehicles. Results indicate that properly selected rumble strips can be cost-effective in reducing vehicle speeds in highway work zones. Police presence combined with rumble strips was shown to be most effective, reducing speeds of all major vehicle types by 4.83 to 9.66 km/h (3.0 to 6.0 mph).

In addition to the preceding papers, this issue includes a Construction Forum prepared by Cliff Schexnayder, as well as an article entitled “Comments on Using Dimensional Limestone.” It also includes a section on Books. A particular book described and recommended by Professor Schexnayder is entitled Wedding of the Waters—The Erie Canal and the Making of a Great Nation, by Peter L. Bernstein. Professor Schexnayder also calls our attention to a conference: “Construction in Developing Economies: New Issues and Challenges—January 18–20, 2006, in Santiago, Chile.

Also included in this issue is a book review of Introduction to Optimum Design, by Jasbir Arora (Elsevier Academic, ISBN 0-12-064155-0). The book review was prepared by Professor Jamshid Mohammadi of the Illinois Institute of Technology, Chicago.