scholarly journals Blind comparison of non-invasive shear wave velocity profiling with invasive methods at bridge sites in Windsor, Ontario

2020 ◽  
Vol 129 ◽  
pp. 105906
Author(s):  
Alex Bilson Darko ◽  
Sheri Molnar ◽  
Abouzar Sadrekarimi
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Non Invasive ◽  
Blind Comparison

scholarly journals Korelasi Antara Nilai SPT-N dan Kecepatan Gelombang Geser (Shear Wave Velocity) Dalam Bidang Engineering

JURNAL HADRON ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 36-43
Author(s):  
Sabrian Tri Anda
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Non Invasive

Metode geofisika telah digunakan secara luas dalam ranah keteknikan terutama dalam bidang investigasi terkait geoteknik. Metode geofisika dianggap mampu untuk menyajikan cakupan ruang lingkup pengukuran yang luas, dengan waktu pengukuran yang lebih efektif, non-invasive, dengan biaya yang tidak terlalu mahal jika dibandingkan dengan metode pengukuran secara tradisional yaitu menggunakan lubang bor untuk pengujian. Penelitian ini bertujuan untuk melihat hubungan antara parameter teknik seperti standard penetration blow count test (SPT-N) dan kecepatan rambat gelombang geser (shear wave velocity) dalam menentukan tingkat kekuatan tanah. Penelitian ini dilakukan di dua area terpisah dengan kondisi geologi yang berbeda pula. Studi area pertama terletak di Sungai Batu, Kedah, Malaysia dan area kedua terletak di komplek Universiti Sains Malaysia, Penang, Malaysia. Dari hasil pengukuran didapatkan bahwa keterkaitan antara nilai SPT-N dan kecepatan rambat gelombang S (geser) adalah sangat erat untuk kedua studi area. Hubungan keterkaitan ini dijabarkan berdasarkan nilai koefisien determinasi.

Shear-wave velocity profiling at sites with high stiffness contrasts: a comparison between invasive and non-invasive methods

2009 ◽  
Vol 8 (1) ◽  
pp. 75-94 ◽  
Author(s):  
Michele Cercato ◽  
Fabrizio Cara ◽  
Ettore Cardarelli ◽  
Gerardina Di Filippo ◽  
Giuseppe Di Giulio ◽  
...  
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Non Invasive ◽  
High Stiffness

Comparison of Invasive and Non-Invasive Methods in Site Response, Case Study: Soil Deposits of La Estrella

2021 ◽  
Vol 906 (1) ◽  
pp. 012119
Author(s):  
Daniel Largo ◽  
César Hidalgo ◽  
Juan Olarte
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Spectrum Analysis ◽  
Site Response ◽  
Response Spectrum ◽  
Response Spectrum Analysis ◽  
Non Invasive ◽  
Soil Deposits ◽  
Relative Differences

Abstract A great part of the Colombian territory is under medium to high seismic hazard due to the complex tectonic condition, which in turn affects, particularly, areas where the population density is highest. A response spectrum analysis of the ground is currently required by seismic design codes for site response analysis. For this, the shear wave velocity (Vs) profile must be established. The use of seismic invasive methods such as Down Hole or Cross Hole for the determination of the shear wave velocity (Vs), has been typically recommended. In recent years, significant progress has been made in non-invasive seismic methods such as MasW (Multichannel Analysis of Surface Waves) and ReMi (Refraction Microtremor), in order to estimate the Vs profile from surface waves analysis. Due to the accessibility and low cost, these methods represent a viable alternative to determine the profile of Vs. In this project, the seismic response of soil deposits was evaluated in the La Estrella municipality located in the south of The Aburrá Valley. One-dimensional (1D) models were simulated by characterizing the soil profile through the shear wave velocity with MasW and ReMi seismic tests. The results were compared with models based on shear wave characterization through Down Hole methods. The 1D response spectrums were determined with an equivalent linear model in DEEPSOIL and GTS NX software. The resulting spectra were compared through relative difference and correlation coefficient. Final results demonstrated that the spectra present low relative differences for long periods, moderate relative differences for moderate periods, and low to moderate relative differences for short periods. The general correlation coefficients were 0.6. This was evidence that non-invasive seismic methods allow an appropriate response spectrum analysis.

scholarly journals Reliability of testicular stiffness quantification using shear wave elastography in predicting male fertility: a preliminary prospective study

2018 ◽  
Vol 20 (2) ◽  
pp. 141 ◽  
Author(s):  
Alpaslan Yavuz ◽  
Adem Yokus ◽  
Kerem Taken ◽  
Abdussamet Batur ◽  
Mesut Ozgokce ◽  
...  
Keyword(s):  
Prospective Study ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Sperm Count ◽  
Shear Wave Elastography ◽  
Non Invasive ◽  
Sperm Counts ◽  
Wave Technique ◽  
The Mean

Aims: To evaluate the reliability of testicular stiffness quantification using shear wave elastography in predicting the fertility potential of males and for the pre-diagnosis of disorders based upon sperm quantification. Material and methods: One hundred males between the ages of 19-49 years (mean age of 28.77±6.11), ninety of whom with complaints of infertility, were enrolled in this prospective study. Scrotal grey-scale, Doppler ultrasound (US), and mean testicular shear wave velocity quantifications (SWVQs) were performed. The volumes of testes, as well as the grade of varicocele if present, were recorded. The mean shear wave velocity values (SWVVs) of each testis and a mean testicular SWVV for each patient were calculated. The semen-analyses of patients were consecutively performed. Results: There were significant negative correlations between the mean testicular SWVVs of patients and their sperm counts or the testis volumes (r=-0.399, r=-0.565; p<0.01, respectively). A positive correlation was found between testicular volumes and sperm counts (r=0.491, p<0.01). The cut-off values regarding mean testicular SWVV to distinguish normal sperm count from azoospermia and oligozoospermia were 1.465 m/s (75.0% sensitivity and 75.0% specificity) and 1.328 m/s (64.3% sensitivity and 68.2% specificity), respectively, and the value to distinguish oligozoospermia from azoospermia was 1.528 m/s (66.7% sensitivity, 60.7% specificity). Conclusion: The mean testicular SWVQ using the ARFI shear wave technique was a reliable, non-invasive and acceptably stable method for predicting male infertility, especially related to sperm count issues. 

scholarly journals Calibrating a new attenuation curve for the Dead Sea region using surface wave dispersion surveys in sites damaged by the 1927 Jericho earthquake

Solid Earth ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 379-390 ◽  
Author(s):  
Yaniv Darvasi ◽  
Amotz Agnon
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Dead Sea ◽  
Attenuation Curve ◽  
Surface Wave Dispersion ◽  
Near Surface ◽  
Moderate Seismicity ◽  
Local Point ◽  
The Dead

Abstract. Instrumental strong motion data are not common around the Dead Sea region. Therefore, calibrating a new attenuation equation is a considerable challenge. However, the Holy Land has a remarkable historical archive, attesting to numerous regional and local earthquakes. Combining the historical record with new seismic measurements will improve the regional equation. On 11 July 1927, a rupture, in the crust in proximity to the northern Dead Sea, generated a moderate 6.2 ML earthquake. Up to 500 people were killed, and extensive destruction was recorded, even as far as 150 km from the focus. We consider local near-surface properties, in particular, the shear-wave velocity, as an amplification factor. Where the shear-wave velocity is low, the seismic intensity far from the focus would likely be greater than expected from a standard attenuation curve. In this work, we used the multichannel analysis of surface waves (MASW) method to estimate seismic wave velocity at anomalous sites in Israel in order to calibrate a new attenuation equation for the Dead Sea region. Our new attenuation equation contains a term which quantifies only lithological effects, while factors such as building quality, foundation depth, topography, earthquake directivity, type of fault, etc. remain out of our scope. Nonetheless, about 60 % of the measured anomalous sites fit expectations; therefore, this new ground-motion prediction equation (GMPE) is statistically better than the old ones. From our local point of view, this is the first time that integration of the 1927 historical data and modern shear-wave velocity profile measurements improved the attenuation equation (sometimes referred to as the attenuation relation) for the Dead Sea region. In the wider context, regions of low-to-moderate seismicity should use macroseismic earthquake data, together with modern measurements, in order to better estimate the peak ground acceleration or the seismic intensities to be caused by future earthquakes. This integration will conceivably lead to a better mitigation of damage from future earthquakes and should improve maps of seismic hazard.

scholarly journals Multi-method site characterization to verify the hard rock (Site Class A) assumption at 25 seismograph stations across Eastern Canada

2021 ◽  
pp. 875529302110010
Author(s):  
Sameer Ladak ◽  
Sheri Molnar ◽  
Samantha Palmer
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Hard Rock ◽  
Site Characterization ◽  
Eastern Canada ◽  
Site Class ◽  
Paleozoic Rock ◽  
Rock Types ◽  
Site Period

Site characterization is a crucial component in assessing seismic hazard, typically involving in situ shear-wave velocity ( VS) depth profiling, and measurement of site amplification including site period. Noninvasive methods are ideal for soil sites and become challenging in terms of field logistics and interpretation in more complex geologic settings including rock sites. Multiple noninvasive active- and passive-seismic techniques are applied at 25 seismograph stations across Eastern Canada. It is typically assumed that these stations are installed on hard rock. We investigate which site characterization methods are suitable at rock sites as well as confirm the hard rock assumption by providing VS profiles. Active-source compression-wave refraction and surface wave array techniques consistently provide velocity measurements at rock sites; passive-source array testing is less consistent but it is our most suitable method in constraining the rock VS. Bayesian inversion of Rayleigh wave dispersion curves provides quantitative uncertainty in the rock VS. We succeed in estimating rock VS at 16 stations, with constrained rock VS estimates at 7 stations that are consistent with previous estimates for Precambrian and Paleozoic rock types. The National Building Code of Canada uses solely the time-averaged shear-wave velocity of the upper 30 m ( VS30) to classify rock sites. We determine a mean VS30 of ∼ 1600 m/s for 16 Eastern Canada stations; the hard rock assumption is correct (>1500 m/s) but not as hard as often assumed (∼2000 m/s). Mean variability in VS30 is ∼400 m/s and can lead to softer rock classifications, in particular, for Paleozoic rock types with lower average rock VS near the hard/soft rock boundary. Microtremor and earthquake horizontal-to-vertical spectral ratios are obtained and provide site period classifications as an alternative to VS30.

scholarly journals The Polito Surface Wave flat-file Database (PSWD): statistical properties of test results and some inter-method comparisons

2021 ◽  
Vol 19 (6) ◽  
pp. 2343-2370
Author(s):  
Federico Passeri ◽  
Cesare Comina ◽  
Sebastiano Foti ◽  
Laura Valentina Socco
Keyword(s):  
Surface Wave ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Active Surface ◽  
Statistical Properties ◽  
Test Results ◽  
Flat File ◽  
Research Fields ◽  
Database Content

AbstractThe compilation and maintenance of experimental databases are of crucial importance in all research fields, allowing for researchers to develop and test new methodologies. In this work, we present a flat-file database of experimental dispersion curves and shear wave velocity profiles, mainly from active surface wave testing, but including also data from passive surface wave testing and invasive methods. The Polito Surface Wave flat-file Database (PSWD) is a gathering of experimental measurements collected within the past 25 years at different Italian sites. Discussion on the database content is reported in this paper to evaluate some statistical properties of surface wave test results. Comparisons with other methods for shear wave velocity measurements are also considered. The main novelty of this work is the homogeneity of the PSWD in terms of processing and interpretation methods. A common processing strategy and a new inversion approach were applied to all the data in the PSWD to guarantee consistency. The PSWD can be useful for further correlation studies and is made available as a reference benchmark for the validation and verification of novel interpretation procedures by other researchers.

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