Application of 2D full-waveform tomography on land-streamer data for assessment of roadway subsidence

Abstract

Roadways are key components of the modern transportation system. Therefore, assessment of roadway subsidence is critical to the health and safety of the traveling public. Existing seismic refraction and waveform tomography methods can be used for subsidence evaluation; however, the data acquisition time is significant because they require multiple source impacts (shots) along a test line. To mitigate the negative impact caused by closing the traffic flow under seismic testing, a land-streamer seismic testing system and waveform analysis are developed. An existing 2D Gauss-Newton full-waveform inversion (FWI) method is extended for analysis of the land-streamer waveform data. The main advantage of using land-streamer waveform data is that geophones are not coupled to test materials and source-receiver offsets are fixed; thus, the whole test system can be moved along the roadway quickly for data acquisition. To demonstrate the effectiveness of land-streamer waveform data, the FWI method was tested on synthetic and field data sets. The synthetic result reveals that buried voids can be well-characterized by the land-streamer waveform analysis. Field data were collected on asphalt pavement using a 24 channel land streamer and a propelled energy generator to induce seismic wave energy. The test system was towed by a pickup truck along a roadway with an on-going subsidence (repaired sinkhole). The data were collected over 277.5 m distance at a 3 m interval, and the total data acquisition time was approximately 1 h. The field data result indicates that the waveform analysis was able to delineate low-velocity soil zones and laterally variable bedrock. The FWI results are also compared with multichannel analysis of surface wave (MASW) results. The 2D [Formula: see text] profiles from the FWI and MASW methods are consistent; however, the FWI method provides more detailed information ([Formula: see text] of [Formula: see text] cells) of low-velocity anomalies for assessment of roadway subsidence.

High-Resolution Characterization of Near-Surface Structures by Surface-Wave Inversions: From Dispersion Curve to Full Waveform

“…Thus, FWI features higher resolution and better applicability to heterogeneous models. Tran and Sperry (2018) showed a relatively good agreement between near-surface structures estimated by FWI and MASW. However, there is no detailed comparison between the performances of MASW and FWI and, thus, little information on how to appropriately choose them to process shallow-seismic surface waves.…”

An H/V Geostatistical Approach for Building Pseudo-3D Vs Models to Account for Spatial Variability in Ground Response Analyses I: Model Development

“…These assumptions are generally violated, which has been shown to introduce bias into tomography (Chen et al, 2018;Picozzi et al, 2009;Ritzwoller and Levshin, 1998;Yang et al, 2007). FWI also faces challenges pertaining to inconsistent source excitation, variable coupling of sensors, lack of low-frequency waves, and high computational complexity in terms of both time and memory (Tran et al, 2013;Tran and Sperry, 2018;Virieux and Operto, 2009). Finally, the need for wide-aperture surveys with numerous, simultaneously recording sensors, which is not practical in urban areas, is another limitation for both tomography and FWI.…”

Efficient tunnel detection with waveform inversion of back-scattered surface waves

“…Wang et al (2018) and Smith et al (2018) applied the 2D and 3D FWI to detect a 10meter-deep hand-dug tunnel at the Yuma Proving Ground, Arizona. Tran and Sperry (2018) applied FWI with a land-streamer acquisition system to assess roadway subsidence. Sherman et al (2018) determined the location of a manmade tunnel at the Black Diamond Mines, CA.…”