Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.555234
Title: Effect of rate of shearing on resistance in fine grained soil
Author: Yusoff, Nor Azizi bin
Awarding Body: University of Sheffield
Current Institution: University of Sheffield
Date of Award: 2011
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Abstract:
Geotechnical design relies on correct interpretation of field observations from site investigation, full scale testing and laboratory element strength tests. A wide spectrum of applied shear strain rates are adopted which have the potential to generate conflicting soil strength parameters. Modern geotechnical applications frequently operate at significantly higher levels of applied shear strain rate than traditional construction methods. This can often lead to overestimation of strength parameters and thus caution must be exercised when interpreting data to prevent unsafe design. A new Rowe Cell-Vane Shear apparatus has been developed to investigate the relationship between undrianed shear strength and rate effects. This apparatus is capable of providing a torque up to 20Nm and rotation rates from O.5mm/s to 400mm/s. The consolidometer was 254 mm in diameter and 126 mm high, with an aluminium base plate designed to accommodate four vanes during consolidation. Rigorous calibrations have been conducted to account for vane shaft friction and motor lag time. Three design mixes were established by using a mixture of Speswhite Kaolin, a silica flour (Oakamoor HPF3) and a silica sand (Buckland P30) at different percentages. The design mixes covered a range of Atterberg limits from low to high plasticity. Functionality of the newly developed apparatus is confirmed through the test results. Rate effects were observed for the peak undisturbed, residual undisturbed and residual disturbed strengths. The rate effects on peak undisturbed shear strength increased with decreasing LI. The results from three different soils at similar liquidity indices indicated that the rate effect was dependant on liquidity index not the plastic limit or liquid limit.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.555234  DOI: Not available
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