Practice Periodical on Structural Design and Construction

Although advanced computer programs to predimension, design, and detail structural components have become so widely used and even necessary for most engineering offices, classical tools, such as design charts and tables, still find their fans in the industry. This is because many engineering tasks are more efficiently carried out if the traditional design charts and tables are used. Therefore, there is no question in whether design charts and tables should be made available to practicing engineers; the question is: should they be confined to the world of paper? Or would it be more beneficial to bring the convenience of a design chart to the engineer’s computer screen while improving its usefulness. To illustrate this concept, an MS Excel application that produces unbraced beam design charts, similar to the ones that are found in the AISC Manual of Steel Construction, was developed by the writer. This paper describes how this application was developed and gives examples of its use. Recommendations pertaining to future developments in the field are given in conclusion.

Many bridges are constructed in groups of simple spans. This construction system requires the use of deck (expansion) joints over piers, leading to numerous problems that are costly to maintain or repair. The use of jointless bridge decks is one of the alternatives gaining popularity among bridge engineers and officials. The construction of new bridges without expansion joints, or the elimination of expansion joints in existing bridges, reduces a great portion of the direct and indirect costs associated with the use of expansion joints. In this paper, a method is proposed for the flexural analysis of bridges with jointless decks. Partial continuity resulting from the link slab is investigated, and results obtained from the proposed method are verified using experimental data found in the literature and a detailed finite element model. The proposed method is utilized in a parametric study to investigate the effects of span length ratios, link slab stiffness, 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. Finally, conclusions and recommendations are drawn.

Given the preliminary layout of a building, the vertical members will be relocated through optimization techniques to obtain the best building performance possible when subjected to lateral loads under specified constraints. The analysis is based on a nonlinear programming algorithm and the movable elements are chosen using a sensitivity analysis. The optimization will be done for static constraints. The analysis is carried out in conjunction with a finite element code. Examples are presented.

The objective of this study 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 will be able to withstand hurricane or tornado wind speeds up to $225\mathrm{km}∕\mathrm{h}\left(140\mathrm{mph}\right)$ and associated windborne debris. Structural calculations for known material strengths, expected wind pressures, and missile impact capacity from previous research were used as the basis for the hurricane room technology. The retrofitting is achieved through reinforcing existing walls and roofs of typical small interior rooms with plywood sheets, steel plates, anchor bolts, hurricane straps and impact resistant doors. The in-house shelter, which can also be constructed as a stand-alone unit, will offer significant occupant protection and reduce the demand on public shelters in the event of mid-Category-4 hurricane. The total cost of a hurricane room is about $3,000 including readily available materials and complete labor, a significant saving over the published cost of a FEMA tornado safe room.

The El Niño phenomena affects a great portion of South America, especially the northern coast of Perú where the River Piura flows into the Pacific Ocean. During the mega El Niño events, in 1983 and 1998, large areas of the Department of Piura suffered serious flood damage. This paper describes the construction of a physical model for studying the flow of the Piura River. The model was commisssioned as a direct result of the river flood damage that occurred during the 1998 El Niño. The model is located at the Institute of Hydraulics, Hydrology, and Sanitary of the Univ. de Piura, Perú

Policy makers make key decisions regarding economic development, but engineers are central to the implementation of these policies. With the realization that economic development and environment are interlinked, engineers are well advised to ensure avoidance of adverse impacts on society and environment by adopting better practices during the design and implementation of construction projects. The objective of this paper is to present a project’s proponents and construction contractors with a framework to identify the environmental risks early in a project’s life so that a proper plan could be developed to mitigate the impact of them. The paper also discusses options currently available in Canada for environmental-type insurance and contractual liability indemnity clauses. A survey conducted among construction companies to assess current risk-management practices in the construction industry show that although many companies are concerned about the possible implications of environmental risks to their project, there still needs to be more emphasis on identification and mitigation of these risks and the need to have a comprehensive framework to properly identify and develop an action plan for environmental related risk issues. The current research trends to achieve these objectives are also outlined in the paper.

This paper presents the results of a field study conducted on western New York State (NYS) highway work zones to evaluate two types of speed control devices: (1) rumble strips, and (2) police presence in combination with rumble strips. The study included speed measurements of approximately 554,400 vehicles. The most commonly used rumble strips comprise of either raised asphalt humps, or grooves cut in the pavement. In both of these two practices, the pavement is damaged, and the layout requires closing the road for extended periods. This project tested the effectiveness of two types of rumble strips: 3M and Swarco. These rumble strips do not damage the pavement, have the potential of repeated use, and are installed in a short period of time. The 3M rumble strips utilized on Interstate-86 were effective in reducing the passenger car (PC) speeds by approximately $3.86\mathrm{km}∕\mathrm{h}\left(2.4\mathrm{mph}\right)$ , the two-axle four-tire vehicle speeds by $2.25\mathrm{km}∕\mathrm{h}\left(1.4\mathrm{mph}\right)$ , and the five-axle single trailer vehicles by $3.22\mathrm{km}∕\mathrm{h}\left(2.0\mathrm{mph}\right)$ . The speed reductions were dependent upon the type of lane closure setup. The Swarco rumble strips installed on Interstate-990, were not effective in reducing vehicle speeds, in either lane. The results of this field research 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 proven to be most effective, reducing speeds of all major vehicle types from $4.83\text{to}9.66\mathrm{km}∕\mathrm{h}$ (from $3.0\text{to}6.0\mathrm{mph}$ ).