Field Measurements of Shear Wave Velocity Profiles in the New Madrid Seismic Zone Using the NEES Field Shaker

2011 ◽  
Author(s):  
Brent Rosenblad ◽  
Jianhua Li ◽  
Jonathan Bailey ◽  
Ryan Goetz
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Field Measurements ◽  
Velocity Profiles ◽  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
New Madrid

Transportation Routes in Soils Susceptible to Ground Failure: New Madrid Seismic Zone

2000 ◽  
Vol 1736 (1) ◽  
pp. 127-133
Author(s):  
Salome Romero ◽  
Glenn J. Rix ◽  
Steven P. French
Keyword(s):  
Remote Sensing ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Data Sources ◽  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
Remote Sensing Imagery ◽  
Geologic Maps ◽  
Transportation Routes

Geologic deposits susceptible to ground motion amplification under seismic loading in the New Madrid Seismic Zone are delineated using multiple data sources including in situ measurements, geologic maps, and remote-sensing imagery. Soils are classified on the basis of the recommendations from the National Earthquake Hazards Reduction Program, which recommends a classification based on the average shear wave velocity of the geologic material in the upper 30 m. Measurements of shear wave velocity were obtained from Central United States Earthquake Consortium state geologists, the U.S. Geological Survey, and several researchers. However, since this is a predominantly rural area, limited field test data are available. Therefore, several other data sources are introduced including geologic maps and remote-sensing imagery to extrapolate dynamic properties in areas lacking extensive field measurements. Each data source was incorporated into a geographic information system for subsequent analysis. Bridges susceptible to failure from amplification of seismic waves and located on key transportation routes are identified for subsequent risk assessment or seismic retrofitting since the performance of these structures affects disaster planning and rescue efforts and may have severe consequences for the national economy.

Flat Dilatometer (DMT), Cone Penetrometer (CPT) and Seismic Cone (SCPT) Evaluation of Select New Madrid Liquefaction Sites

1992 ◽  
Vol 63 (3) ◽  
pp. 357-366
Author(s):  
Roman D. Hryciw
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Horizontal Stress ◽  
Stress Index ◽  
Seismic Zone ◽  
Cone Penetration ◽  
Seismic Shear ◽  
Tip Resistance ◽  
New Madrid

Abstract Cone Penetration (CPT), Flat Dilatometer (DMT) and Seismic Shear Wave Velocity tests were conducted in four regions of the New Madrid seismic zone. Test results are compared to existing liquefaction criteria and to surface evidence of liquefaction (sandblows) during the 1811–1812 events. In general, all three tests confirm the presence of liquefaction-prone strata at locations with evidence of liquefaction. A “sand blow index” (SBI), which accounts for both local and regional sand blow intensity, correlates reasonably well against the minimum values of DMT horizontal stress index, the normalized CPT tip resistance, and the normalized shear wave velocity at each test location. An upperstratum clay also appears to play a significant role in inhibiting sand blow formation. Its thickness also correlates well with the SBI.

scholarly journals Evaluation of liquefaction potentials based on shear wave velocities in Pohang City, South Korea

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yumin Ji ◽  
Byungmin Kim ◽  
Kiseog Kim
Keyword(s):  
South Korea ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Ground Surface ◽  
Velocity Profiles ◽  
Liquefaction Potential ◽  
Attenuation Relationships ◽  
Cyclic Resistance ◽  
Sand Boils

AbstractThis study evaluates the potentials of liquefaction caused by the 2017 moment magnitude 5.4 earthquake in Pohang City, South Korea. We obtain shear wave velocity profiles measured by suspension PS logging tests at the five sites near the epicenter. We also perform downhole tests at three of the five sites. Among the five sites, the surface manifestations (i.e., sand boils) were observed at the three sites, and not at the other two sites. The maximum accelerations on the ground surface at the five sites are estimated using the Next Generation Attenuation relationships for Western United State ground motion prediction equations. The shear wave velocity profiles from the two tests are slightly different, resulting in varying cyclic resistance ratios, factors of safety against liquefaction, and liquefaction potential indices. Nevertheless, we found that both test approaches can be used to evaluate liquefaction potentials. The liquefaction potential indices at the liquefied sites are approximately 1.5–13.9, whereas those at the non-liquefied sites are approximately 0–0.3.

scholarly journals Evaluating simplified methods for liquefaction assessment for loss estimation

2017 ◽  
Vol 17 (5) ◽  
pp. 781-800 ◽  
Author(s):  
Indranil Kongar ◽  
Tiziana Rossetto ◽  
Sonia Giovinazzi
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Ground Deformation ◽  
Insurance Industry ◽  
Binary Classification ◽  
Remote Sensing Data ◽  
Velocity Profiles ◽  
Loss Estimation ◽  
Liquefaction Assessment

Abstract. Currently, some catastrophe models used by the insurance industry account for liquefaction by applying a simple factor to shaking-induced losses. The factor is based only on local liquefaction susceptibility and this highlights the need for a more sophisticated approach to incorporating the effects of liquefaction in loss models. This study compares 11 unique models, each based on one of three principal simplified liquefaction assessment methods: liquefaction potential index (LPI) calculated from shear-wave velocity, the HAZUS software method and a method created specifically to make use of USGS remote sensing data. Data from the September 2010 Darfield and February 2011 Christchurch earthquakes in New Zealand are used to compare observed liquefaction occurrences to forecasts from these models using binary classification performance measures. The analysis shows that the best-performing model is the LPI calculated using known shear-wave velocity profiles, which correctly forecasts 78 % of sites where liquefaction occurred and 80 % of sites where liquefaction did not occur, when the threshold is set at 7. However, these data may not always be available to insurers. The next best model is also based on LPI but uses shear-wave velocity profiles simulated from the combination of USGS VS30 data and empirical functions that relate VS30 to average shear-wave velocities at shallower depths. This model correctly forecasts 58 % of sites where liquefaction occurred and 84 % of sites where liquefaction did not occur, when the threshold is set at 4. These scores increase to 78 and 86 %, respectively, when forecasts are based on liquefaction probabilities that are empirically related to the same values of LPI. This model is potentially more useful for insurance since the input data are publicly available. HAZUS models, which are commonly used in studies where no local model is available, perform poorly and incorrectly forecast 87 % of sites where liquefaction occurred, even at optimal thresholds. This paper also considers two models (HAZUS and EPOLLS) for estimation of the scale of liquefaction in terms of permanent ground deformation but finds that both models perform poorly, with correlations between observations and forecasts lower than 0.4 in all cases. Therefore these models potentially provide negligible additional value to loss estimation analysis outside of the regions for which they have been developed.

Sign in / Sign up

Export Citation Format

Share Document