Progress in Engineering Computational Technology
Chapter 15 F.C. Hadipriono
Department of Civil and Environmental Engineering, The Ohio State University, Columbus, Ohio, United States of America Keywords: building collapse, building failure, criminogenic design, CPTED, crime, defensible space, premeditated destructive event, terrorist action, synthetic environment, virtual reality.
Premeditated destructive events (PDEs) perpetrated by terrorists have led to the development of new approaches to avoid the impact of such atrocities on constructed facilities. In this paper, the author introduces the use of criminogenic design of a typical multi-story building and its surrounding in a synthetic environment. Here, the term "criminogenic design" refers to crime prevention through environmental design (CPTED) whose strategies include territorial reinforcement, natural surveillance, building forms, building construction, and compatible building placement. Territorial reinforcement increases the territorial ownership and, thus, responsibility of owners to keep their property safe and secure. Surveillance establishes natural areas within the territorial perimeter and barriers by maximizing occupants' and passers-by's observability. Building forms and shapes play an essential role in enhancing observability and diminishing blast impact. Building construction establishes the strength of the building to resist bomb blasts. Its construction must be sufficiently strong to resist the explosive effects of a placed bomb. Compatible building placement suggests the grouping of compatible buildings and placing residential developments adjacent to non-threatening activities. Although numerous approaches may be employed in concurrence with CPTED, earlier studies conducted by the author suggest the benefits of using the model in a virtual environment [1,2]. Hence, a preliminary stage of a Virtual PDE was developed in response to the needs to visualize and assess the hot-spots of PDEs and the weak-spots of the targeted facility. In particular, studying terrorist destructive events on constructed facilities presents certain challenges, in that such events are rare and extreme, not the least of which is the complexity involved in simulating their consequences on a constructed facility. The Virtual PDE incorporates real and created imagery of a targeted constructed facility and its surroundings in a synthetic environment; hence, it enables a user to "walk-around" or "walkthrough" onto a computer-created simulation of a constructed facility and "fly-over" its synthetic environment, giving a more realistic representation than would be possible just by viewing blue prints, photographs, or videotapes. In this paper, the author uses terms such as "synthetic environment," "cyber-space," and "virtual world" interchangeably to represent a simulated setting that approaches a real world condition. Among the potential benefits of Virtual PDE are its use (1) to simulate and assess the adequacy and vulnerability of multi-story buildings and their surroundings subjected to various PDEs, (2) to design and construct PDE-resistant structures through the use of virtual object library, and (3) to train and educate novice individuals who are not familiar with the etiology, intervention and consequence of PDEs on a typical constructed facility. Thus, this approach will bring a better understanding of premeditated destructive activities and their consequences on a constructed facility. Central to the development of the Virtual PDE is the system configuration of the model, construction of 3-D objects, interactive navigation module, and interactive positioning module. For illustration purposes, the development of a Virtual PDE in this paper focuses on a typical federal building, such the Alfred P. Murrah Federal Building in Oklahoma City that was destroyed by a PDE in 1995. A graphics workstation Onyx Reality Engine 2 (RE2), a high performance graphics system was used as the workstation platform to develop the building model. A head-mounted display (HMD) and a cyberglove are employed for users to interface with the model when using the workstation platform. Walkthroughs of the Murrah Building in a virtual environment illustrate deficiencies in the original design that could have been overcome by using certain elements of the Crime Prevention Through Environmental Design (CPTED) approach that are related to PDE. The investigation suggested a list of potential improvements that could be applied to the building (or other similar buildings) to reduce its vulnerability to bombings. The illustration presented in this paper shows the installation of these planters to prevent vehicles from coming to close to the building, and at the same time providing additional mass to reduce the impact of a vehicle bomb and to localize the impact of a placed-bomb within the plaza. The application of CPTED components to Virtual PDE is not exhaustive; more will be introduced as research progresses.
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