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VISUALIZATION OF GEOTECHNICAL DATA FOR HAZARD MITIGATION AND DISASTER RESPONSE Visualization of geotechnical data can be an extremely valuable technique for mitigating hazards and responding to the consequences of disasters and extreme events. Geotechnical data visualization (GDV) can be broadly defined as graphic presentation of geotechnical data intended to provide insight into the nature of the problem at hand and to develop potential solutions for that problem. The tools currently used for visualization of geotechnical data include geotechnical-specific applications, applications adapted from other professions, and general-purpose applications such as spreadsheets and image analysis software. The first objective of this study was to understand the nature and quantity of the geo- technical hazards, disasters, and extreme events that transportation personnel must prepare for and react to. The second objective was to understand what geotechnical data are avail- able to transportation personnel and how the data are stored and visualized. The information gained from the first two approaches provided a context for the third objective: synthesizing the reported effectiveness of data visualization tools in developing and implementing geo- technical hazard mitigation measures and responding to geotechnical disasters or extreme events. The findings reported in this study will provide geotechnical leaders in transportation with an overview of what tools and techniques their colleagues are using and how effective those tools and techniques are for mitigating geotechnical hazards and responding to geo- technical disasters. Geotechnical data encompasses a varied and complex set of information derived from field reconnaissance, subsurface explorations, field tests, laboratory tests, in-situ instrumen- tation, and remote sensing measurements. The data may consist of geologic setting, physical properties, or performance characteristics. Geotechnical data range in scale from laboratory tests of small samples to field measurements of mass performance, to wide-area images provided by satelliteâborne remote sensing devices. Because these data come from many different sources in many different formats, the greatest challenge to those responsible for hazard mitigation and disaster response is often simply accessing, viewing, and interpreting geotechnical data in a consistent and convenient format. The natural phenomena that lead to hazards or disasters with a geotechnical component may have geological origins (e.g., earthquakes or volcanoes) or meteorological origins (extreme precipitation or temperature, etc.). Hazards, disasters, and extreme events with a geotechnical basis include landslides, rockfalls, settlement, sinkholes, and many other events that can degrade or destroy a transportation system. Ideally, every geotechnical hazard associated with a transportation system would be miti- gated before a disaster occurs. However, this is not feasible. The economics of mitigating every hazard is unachievable and our ability to recognize, prioritize, and mitigate hazards is imperfect. Consequently, a certain level of risk in building and maintaining transportation systems must be accepted; the most dangerous hazards must be mitigated, and disasters must be responded to as they occur. The role of visualization of geotechnical data is to help reduce those risks by more efficiently identifying hazards and improving mitigation efforts, disaster response, and disaster recovery. SUMMARY
2 Although the hazards and potential disasters and extreme events may vary from state to state, and even region to region, the effective use of GDV tools and methods in one location can be expected to apply to a range of conditions, events, and objectives in another location. A goal of this study was to identify the GDV approaches that are most effective for hazard mitigation and disaster response and recovery. Mitigation and response to geotechnical disasters or extreme events are part of the transpor- tation emergency management cycle. Mitigation of a geotechnical hazard occurs during the preparation phase, with an objective of avoiding or minimizing hazards and reducing disaster consequences. During the response phase, immediately following a disaster, the focus is on public and worker safety and minimizing transportation system delays or detours. Mitigation also occurs during the recovery phase of restoring the transportation system to a pre-event level of service. Recovery mitigation is also an opportunity to make improvements to aging infrastructure by rebuilding a more resilient transportation system than existed previously. The primary sources of information for the study were a literature review; a survey of U.S. state department of transportation (DOT) geotechnical leaders; and interviews with selected railroad and pipeline geotechnical personnel, visualization research leaders in academia, and GDV software vendors. The literature review was used to obtain an overview of the research and development (R&D) underway in the field of GDV and to sample the case histories that illustrate the value and limitations of GDV in practice. An exhaustive list of all publications from as few as the last 10 years would likely run to thousands of citations. Consequently, the bibliography attached to this report is only a small sampling of the more recent publications. Considering the current and likely continuing rapid pace of technological change, preference in building the bibliography was given to more recent publications. The publications found in the literature review represent a broad spectrum of GDV pur- poses, technologies, and methods. Although the publications that describe case histories or new methods are usually for a specific transportation system type (e.g., road, rail, or pipeline), the lessons learned and methods described are generally applicable to any transportation system. It is interesting to note that in the literature there are a number of introspective studies of the impact of visualization technology on the productivity, quality, and mission support in the sciences and engineering. The conclusion of these studies is that, despite cost and imple- mentation challenges, visualization technology has improved the pace, quality, and depth of understanding in the fields where it has been applied. A survey of state DOT geotechnical leaders was undertaken to determine the type and quantity of natural phenomena and geotechnical hazards that they face, what geotechnical data they collect, store and use, and what tools they have at their disposal to visualize geo- technical data; and to gauge the frequency and effectiveness of their use of visualization in mitigating geotechnical hazards and responding and recovering from geotechnical disasters and extreme events. The survey was sent to the geotechnical leaders of the 50 states, the District of Columbia, and Puerto Rico. Responses were received from 41 states and Puerto Rico, a response rate of 81%. On average, state DOT geotechnical leaders and their staffs face five different natural hazards and seven geotechnical hazards, with some states having as many as eight natural phenomena hazards and 12 geotechnical hazards to contend with. Although natural hazards with a geological origin such as earthquakes were reported by many states, the majority of the natural phenomena hazards the states face are meteorological. To identify and mitigate this array of hazards, the state DOTs collect, store, and use a wide range of geotechnical information including exploration and test data, instrumentation Image credit: U.S.DOT http://www.dot.gov/sites/dot. dev/files/docs/Disaster_ National_Transportation_ Recovery_Strategy.pdf.
3 data, and remote sensing data. The typical DOT maintains about eight different types of geo- technical data and six different types of instrumentation data. Some DOTs maintain as many as 14 geotechnical data types and some have as many as 13 instrument data types to manage. Geotechnical data management practices among DOTs range from manual data collection and paper files to the latest instrument data acquisition systems and sophisticated, centralized information management systems. The general consensus among the state DOT geotechnical leaders is that visualization of geotechnical data is valuable for hazard mitigation and disaster response. However, many of the DOTs noted that a significant gap exists between the desired level of data availability and visualization tools and their current ability to achieve that level. Interviews with geotechnical leaders in other transportation system arenas (rail and pipe- line), indicated that they are faced with similar geotechnical hazards, disasters, and extreme events. However, because they represent for-profit organizations, they can more aggressively integrate visualization tools and other technologies into their decision-making processes than may be possible at the state agencies, where a multitude of goals compete for finite funding. The R&D underway in the academic world bodes well for the improvement and wide- spread use of visualization of geotechnical data; not just for hazard mitigation and disaster response, but for geotechnical engineering in general. Much of the R&D is focused on soft- ware, hardware, and data management, but development of improved human-machine inter- action may prove to be the most valuable outcome of this research. Key findings of the literature review, survey, and interviews may be summarized as follows: ⢠The natural phenomena hazards that threaten transportation systems throughout the United States include hazards of geological origin, but are dominated by meteorological hazards. ⢠Almost every type of geotechnical hazard threatens transportation systems, but the most common are unstable rock or soil slopes and embankments, settlement issues, and sinkholes. ⢠The most costly hazards are unstable rock or soil slopes and embankments. ⢠Traditional geotechnical, instrument, and remote sensing data are collected and retained, but some DOTs have yet to implement systems to readily access and visualize the data. ⢠Most DOTs report that geotechnical hazard mitigation is generally successful and that visualization of geotechnical data has an important role in identifying hazards and implementing mitigation measures. ⢠Most geotechnical leaders would like to have a substantial amount of geotechnical data available online and on site during geotechnical disaster response, but relatively few have the facilities to accomplish this goal. ⢠When available, GDV plays an important role in responding to geotechnical disasters. ⢠Visualization of geotechnical data also has an important role in long-term recovery from geotechnical disasters.
