Characterization of Norwegian marine clays with combined shear wave velocity and piezocone cone penetration test (CPTU) data

Forristal

Soil and Tillage Research

2013

Self Cite

Seismic geophysical methods have rarely been used in precision agriculture, predominantly due to the perception that they are slow and results require a complex evaluation. This paper explores the possibility of using a recently developed surface wave seismic geophysical approach, the Multichannel Analysis of Surface Waves (MASW) method, for assessment of agricultural compaction. This approach has the advantage of being non-intrusive, rapid and is able to produce 2D ground models with a relatively high density of spatial sampling points. The method, which was tested on a research site in Oakpark, Ireland, detected a significant difference in shear wave velocity between a heavily compacted headland and an uncompacted location. The results from this approach compared favourably with those obtained from measurements of bulk densityand cone penetrometers and demonstrate that the MASW approach can distinguish between the extreme states of heavily compacted and uncompacted soil.

Section: Maswsupporting

confidence: 58%

“…A number of researchers (e.g. Mayne and Rix 1993;Mayne and Rix 1995;Schnaid et al 2004;Long and Donohue 2010) have observed significant relationships between V s or G max and q c for a range of materials.…”

Section: Introductionmentioning

confidence: 99%

Detection of soil compaction using seismic surface waves

Forristal

Soil and Tillage Research

2013

Self Cite

“…To estimate Young's modulus E for the clay layer, six empirical models were used. One model [43] calculated the initial tangent shear modulus G max , whereas the remaining five models [44][45][46][47][48] calculated the velocity of a shear wave traveling through soil V s with the cone tip bearing resistance q c ; subsequently, the estimated velocity was converted into the initial tangent shear modulus G max using equation (2). All values were calibrated with the ratio of the secant shear modulus and the initial tangent shear modulus (G/G max ) with respect to the shear strain to account for strain dependency.…”

Section: (A))mentioning

confidence: 99%

Dynamic Characteristics of an Offshore Wind Turbine with Tripod Suction Buckets via Full-Scale Testing

Seo

Ryu

2020

Complexity

The dynamic characteristics of an offshore wind turbine with tripod suction buckets are investigated through finite element analysis and full-scale experiments. In finite element analysis, an integrated framework is suggested to create a simple yet accurate high fidelity model. The integrated framework accounts for not only the strain dependency of the soil but also for all dynamics in the seabed, including those of the soil, suction bucket skirt, and cap. Hence, the model accurately describes the coupling effect of translational and rotational motions of the seabed. The prediction results are compared to the experimental results obtained via full-scale testing in four stages during construction and in several operational conditions. The comparison shows that the stiffness of the suction bucket cap and strain dependency of the soil play a significant role in predicting natural frequency, suggesting that these two factors should be considered in finite element analysis for the accurate prediction of dynamic responses of an offshore wind conversion system. Moreover, dynamic analysis of the strain and acceleration measured during operational conditions shows that strain is more robust than acceleration with regard to the characterization of the overall dynamics of an offshore wind conversion system because the natural frequency of an offshore wind turbine is very low. It can be inferred that the measurement of strain is a more effective way to monitor the long-term evolution of dynamic characteristics. The suggested integrated framework and measurement campaign are useful not only to avoid conservatism that may incur additional costs during load calculation and design phases but also to establish an intelligent operation and maintenance strategy with a novel sensing technique.

“…The target of this study is to obtain change of attenuation and velocity of the waves to know subsurface structures. Pressure and shear wave velocity were calculated in the study boreholes and consequent catch geotechnical parameters [3], [4]. These parameters have extensive application and important in the engineering tasks.…”

Section: Introductionmentioning

confidence: 99%

Automatic detection of ovarian cancer based on improved DWT transformation

Rashid

Kaur

2018

IJET

The Sivaki Dam site located near Sepidar Road, approximately 50 km southwest of Yasuj City was selected for geophysical investigations. The objective of the study was to detect low velocity zones potentially liable to water infiltration or leakage and to evaluate the dynamic properties of subsurface materials. The study applied a combination of shallow seismic refraction profiling and seismic tomography methods. The P-wave velocity in most parts obtained from seismic tomography investigation is less than 3km/s. This velocity corresponds to the high Lugeon number (> 10), which is the indicator of high permeability of dam foundation. Based on the seismic tomography and Lugeon section, at the right abutment, rock mass quality improves towards deeper parts but because of high Lugeon value need for grouting at deep levels. According to Iranian-2800, seismic building code the upper layer has average shear velocity values that range from 375 m/s to 750 m/s and classified as hard soil and mixtures of sands, gravels and clays. According to the national earthquake hazard reduction program (NEHRP) provisions scheme, the Sivaki dam site is preliminarily classified into two site classes (B and C).