While primary use of Global Navigation Satellite System (GNSS) is positioning, navigation, and timing (PNT), various GNSS applications have emerged over the past decades that includes GNSS meteorology. GNSS meteorology is the remote sensing of the atmospheric constituents in the neutral atmosphere – mostly in the troposphere - using GNSS...
Damage estimates to the built environment from tsunamis are important for disaster mitigation, including planning emergency response and recovery. This dissertation evaluates the damage states of buildings in a small urban coastal city, Seaside, Oregon, from tsunami hazards generated by a Cascadia Subduction Zone (CSZ) event. This study is separated...
Vertical datum is a reference system used for specifying the elevation of specific points on or near the Earth. Precise and accurate definition and realization of vertical references are, therefore, crucial to ensure consistency between height measurements. The vertical datums can be divided into two categories: 1) vertical geodetic datums...
A typhoon is a highly destructive weather event, causing severe damage and losses to the economy and lives. The impacts of typhoons can be mitigated by adequately predicting their path in advance. The progress of a typhoon can be investigated by analyzing the significant changes in Precipitable Water Vapor (PWV)...
Bridge inspections are vital for monitoring the health and serviceability of transportation infrastructure throughout the world. However, inspections can be logistically-challenging, expensive, and dangerous. For example, inspections may require climbing, as well as the use of scaffolding, ladders, rescue boats, bucket trucks, and/or under-bridge inspection vehicles. Small, multirotor unmanned aircraft...
Real time networks (RTNs) have become popular for Global Navigation Satellite System (GNSS) surveys because highly accurate positions can be derived in seconds to minutes compared to hours as required with static sessions. To evaluate the accuracy of these shorter-duration, RTN GNSS observations and their potential for use as a...
Tsunami inundation of coastal communities can impose a wide array of forces on the
built environment. Forces generated by tsunami-driven debris damming have the potential to
cause failure of coastal structures and further accumulate flow-entrained debris. Since tsunami-resilient design standards were adopted by ASCE in 2016, debris damming considerations have...
This study evaluates the productivity and accuracy of surveys completed with single-base real-time kinematic (RTK) Global Navigation Satellite Systems (GNSS) using four different GNSS constellation combinations: (1) GPS-only, (2) GPS+GLONASS, (3) GPS+Galileo+BeiDou, and (4) GPS+GLONASS+Galileo+BeiDou. For this comparison, we set up a test site consisting of 20 stations ranging with...
Originally used as a method to densify loose soils, controlled blasting has expanded its applicability to geotechnical engineering by becoming a research tool to physically generate liquefaction for full-scale in-situ tests, ranging from seismic performance of deep foundations to evaluating ground improvement techniques. Current methods used to design the blasting...
During the interstate expansion of the 1950s, many conventionally reinforced concrete
deck girder bridges were built throughout the country. These now vintage bridges
commonly exhibit diagonal cracking and rate inadequately for shear, thus they are
candidates for shear strengthening to extend their useful life. Near-surface mounted
(NSM) retrofitting is a...