Journal of Performance of Constructed Facilities

When a terrorist bomb explodes in an urban area, it produces devastating effects, including structural and nonstructural damage to buildings, injuries, and deaths. Numerous injuries in explosions result directly and indirectly from window glass failure. Direct glass-related injuries occur when glass shards flying and falling from fractured windows cause lacerations and abrasions. Secondary glass-related injuries occur when the shock front of the blast wave passes into buildings through fenestrations vacated by fractured glazing. The Oklahoma city bombing killed 167 people and caused numerous injuries. Most of the deaths and many of the injuries occurred in the Alfred P. Murrah Federal Building, the target of the bomb. This event focused the attention of the engineering and security communities on two major issues: the prevention of progressive structural collapse and the design of blast-resistant glazing. This paper discusses glass-related injuries that occurred away from the Alfred P. Murrah Federal Building in Oklahoma City. In particular, it provides information concerning locations of glass-related injury victims in other buildings with respect to their position in proximity to outside walls with glazing. Location data indicate that more than one-quarter of the glass-related injury victims in buildings were positioned within 1.5 m (5 ft) of a wall with glazed fenestrations and nearly one-half of the glass-related injury victims were positioned within 3.0 m (10 ft) of a wall with glazed fenestrations. In addition to suffering lacerations and abrasions, a large number of victims in buildings suffered hearing damage because glazing that failed to maintain closure of fenestrations exposed them to the shock front of the blast wave. Consideration of the injury data justifies a requirement for design of blast-resistant glazing to protect building inhabitants.

In the 19th century, the invention of reinforced concrete (RC) technology paved the way for innovation in building methods, though its actual mechanical behavior was not fully understood for some time afterwards. The early period of the inventors and builders, such as Jean Bordenave, Paul Cottancin, A. Bonna, François Hennebique, Edmond Coignet, and N. de Tedesco, was followed by a time of intensive activity for the theorists, who developed several accurate analysis methods. A considerable contribution to this success came from the builders themselves, who adopted methods capable of achieving an effective distribution of the reinforcement, and from the technical literature, which facilitated the growth of this new technique. Initially, the theories were somewhat confused because different, sometimes contrasting approaches were used by different authors. By way of example, suffice it to mention the hypotheses developed by Mattias Koenen, P. Neumann, Edmond Coignet, N. de Tedesco, Max Ritter von Thullie, Josef Melan, J. B. Johnson, Léon Stellet, L. Lefort, F. Chaudy, Josef Anton Spitzer, Wilhelm Ritter, and Armand Considère. However, RC became a highly successful material for the 20th century, capable of satisfying the most challenging demands of designers and customers. In this paper special attention is paid to the contribution of the theories suggested at the time, in order to verify their validity in relation to our present understanding.

With the widespread use of reinforced concrete (RC) constructions in the latter decades of the 19th century in the main countries of Europe, a number of studies have been performed with a view to evaluating the stress conditions in the structures built with this new material in mathematical terms. This paper deals with part of a research program, one of the purposes of which was to identify any impressions emerging from preliminary studies and investigations and having to do with current theories on RC or, in other words, to verify whether there is any historical continuity between the hypotheses lying behind the early theoretical formulations and our understanding of today. The various calculation methods for bending in singly reinforced slabs and rectangular beams available from the scientific and technical literature around the turn of the century, presented in the companion paper, are here numerically compared, to investigate whether and to what degree these verification and/or design methods are still reliable. The endpoint of the study was thus to provide an operator planning rehabilitation or restoration work with more efficient tools to facilitate a better philological interpretation of the structural behavior of historical RC structures.

An evaluation of runway and taxiway pavements was conducted using technology developed or utilized during the Strategic Highway Research Program (SHRP) to determine the effectiveness for identifying thermal cracking propensity of asphalt pavements. SHRP performance grades (PG) of PG52-28 and PG58-28 were measured for the 3 and 6% (weight-to-weight ratio) styrene-butadiene-styrene copolymer-modified asphalt binders employed in taxiway and runway construction. The high temperature SHRP performance grades were above that required by SHRP for the Anchorage, Alaska area according to the SHRP weather database. The low temperature SHRP PG of the binders were found to be insufficient for the area. No rutting has been observed; however, the pavements developed transverse cracks after the first winter following construction of both the runway and taxiway pavements in 1994 and 1996, respectively. The SHRP thermal cracking model failed to predict any cracking within a 10-year period for both pavements. No obvious cause for the model failure could be ascertained. The thermal stress restrained specimen test revealed no significant difference between cracking temperatures for the 3 and 6% styrene-butadiene-styrene-modified binders.

A new method to nondestructively evaluate existing deep foundations is described for the situation where access to the top of a deep foundation is prevented by an intervening structure. The test consists of striking a surface of a structure and simultaneously recording velocities with vertical geophones at several locations on an impacted surface. Arranging the geophones at different distances from both the impact location and the source of surface wave reflections allows one to minimize the interfering effects of surface waves on recognizing the compression wave reflections from an underlying deep foundation. The processed data can be evaluated as either a conventional sonic echo or impulse response test. Results of field tests of the system are described for groups of shafts at the National Geotechnical Experimentation Site at Northwestern University. Results of these tests indicate that there are preferential locations for the geophones that enhance the interpretation of the condition of an underlying drilled shaft. A case study is presented that describes the application of the method to evaluate possible concrete deterioration of existing bridge piers.