| Autor: |
P. J. Schultheiss, M. T. Hurley |
| Rok vydání: |
1991 |
| Předmět: |
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| Zdroj: |
Shear Waves in Marine Sediments ISBN: 9789401055819 |
| DOI: |
10.1007/978-94-011-3568-9_47 |
| Popis: |
A method for determining an average sea-bed shear modulus (G) of the top few metres of the sea-bed has been developed and tested. The method employs a simple mathematical model and in-situ measurements of the variation of tidally induced pore-pressures with depth. The model is based on Biot’s theory, assuming a homogeneous sea bed with constant physical properties. We tested the model using data collected at Great Meteor East (GME), which is located on the Madeira Abyssal plain of the N Atlantic Ocean. We used in-situ measurements of tidally induced pore-pressures - collected using a pop-up pore-pressure instrument (PUPPI) - along with physical properties data from laboratory experiments on core-samples. We input these measurements into the model and obtained an average value of G = 20 MPa for the first 4 metres of the sea-bed. This value of G is greater than measurements obtained from alternative techniques used at GME. The reasons for these differences are: simplicity of the model; limitations of our in-situ pore-pressure measurements, and the uncertainties present in the alternative techniques. Therefore, we have demonstrated the feasibility of this method of determining G from tidally induced pore-pressure measurements within defined limits. We recommend improvements to the model and the pore-pressure measuring system PUPPI, which will increase the accuracy of shear moduli determined from this method. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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