scholarly journals Shear-wave velocity and attenuation structure beneath Antarctica determined from surface waves

1994 ◽  
Vol 118 (3) ◽  
pp. 515-528 ◽  
Author(s):  
D. D. Singh
Author(s):  
Khiem T. Tran ◽  
Justin Sperry ◽  
Michael McVay ◽  
Scott J. Wasman ◽  
David Horhota

Assessment of roadway subsidence caused by embedded low-velocity anomalies is critical to the health and safety of the traveling public. Surface-based seismic techniques are often used to assess roadways because of data acquisition convenience and large depths of characterization. To mitigate the negative impact of closing a traffic lane under traditional seismic testing, a new test system that uses a land streamer is presented. The main advantages of the system are the elimination of the need to couple the geophones to the roadway, the use of only one source at the end of the geophone array, and the movement of the whole test system along the roadway quickly. For demonstration, experimental data were collected on asphalt pavement overlying a backfilled sinkhole that was experiencing further subsidence. For the study, a 24-channel land streamer and a propelled energy generator to generate seismic energy were used. The test system was pulled by a pickup truck along the roadway and the data were collected with 81 shots at every 3 m for a road segment of 277.5 m, with a total data acquisition time of about 1 h. The measured seismic data set was analyzed by the standard multichannel analysis of surface waves (MASW) and advanced two-dimensional (2-D) waveform tomography methods. Eighty-one one-dimensional shear wave velocity (VS) profiles from the MASW were combined to obtain a single 2-D profile. The waveform tomography method was able to characterize subsurface structures at a high resolution (1.5- × 1.5-m cells) along the test length to a depth of 22.5 m. Very low S-wave velocity was obtained at the repaired sinkhole location. The 2-D VS profiles from the MASW and waveform tomography methods are consistent. Both methods were able to delineate high- and low-velocity soil layers and variable bedrock.


2011 ◽  
Author(s):  
Julian Ivanov ◽  
Richard D. Miller ◽  
Shelby Peterie ◽  
Chong Zeng ◽  
Jianghai Xia ◽  
...  

2021 ◽  
Vol 24 (4) ◽  
pp. 473-484
Author(s):  
Cengiz Kurtuluş ◽  
Ibrahim Sertcelik ◽  
Fadime Sertçelik ◽  
Hamdullah Livaoğlu ◽  
Cüneyt Şaş

In this study, shallow seismic surveys, including seismic refraction, Multichannel Analysis of Surface Waves (MASW), Refraction Microtremor (ReMi), and Microtremor measurements were conducted to estimate site characterization at 26 strong-motion stations of AFAD (Disaster and Emergency Management Presidency) in the province of Hatay, situated in one of the most seismically active regions in southern Turkey. The Horizontal to vertical spectral ratio (HVSR) technique was applied, using smoothed Fourier spectra derived from a long duration series to determine dominant frequency values at different amplification levels. Shear wave velocity up to 30 m of the ground was detected with MASW analysis. In the ReMi analysis, up to 80 m was reached with a corresponding average of 650 m/s shear wave velocity. The shear wave velocities estimated by the MASW method up to 30 m were compared with those found by the ReMi method, and they were observed to be very compatible. The province of Hatay was classified according to Vs30 based NEHRP Provisions, Eurocode-8, the Turkish Building Earthquake Regulation (TBDY-2018), and Rodriguez-Marek et al. (2001). The shear-wave velocity (Vs30), Horizontal to Vertical ratio’s (H/V) peak amplitude, dominant period, and site class of each site were determined. The H/V peak amplitudes range between 1.9 and 7.6, while the predominant periods vary from 0.23 sec to 2.94sec in the study area. These results are investigated to explain the consistency of site classification schemes.


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