APPLICATIONS OF 3D LASER SCANNING TO EARTHQUAKE RECONNAISSANCE

Several recent earthquakes have resulted in a significant amount of damage to public infrastructure. Reconnaissance efforts assist scientists and engineers to understand the extents and nature of the damage. However, there is only a limited time window in which to complete these critical observations. This presentation will discuss analysis performed using ground-based LIDAR data to evaluate damage following recent earthquakes and tsunamis in American Samoa, Chile, and Japan. Several examples of sites with liquefaction, lateral spreading, scouring, erosion, and other forms of ground failure will be highlighted.

3D laser scanning provides several advantages to traditional natural hazard reconnaissance efforts. First, LIDAR enables rapid acquisition of valuable information before clean-up efforts are completed, repairs are made, and vegetation has been restored. Second, although no previous data are generally available at similar resolutions, LIDAR provides high resolution data allowing for more accurate damage quantification than traditional methods. As such, the missing information of initial conditions can be better estimated. Third, this data can be used to calibrate empirical and numerical models related to earthquake and tsunami research. Next, LIDAR creates virtual models, which can be available for scientists to explore and study without having to travel to the site. Further, because reconnaissance teams must cover a lot of ground quickly, important observations can be missed in the field due to time or safety constraints. The LIDAR virtual model overcomes these limitations. Lessons learned from accurate measurements using the LIDAR data are important to understanding the ability of structures to withstand tsunami and earthquake impacts. Such information is valuable to the design and construction of public infrastructure.