Diambra A.,University of Bristol |
Ciavaglia F.,WindSupport Ltd |
Harman A.,Lankelma Ltd |
Dimelow C.,Lankelma Ltd |
And 2 more authors.
Proceedings of the Institution of Civil Engineers: Forensic Engineering | Year: 2014
This paper presents results from a preliminary testing campaign to explore the feasibility and benefits of performing cyclic cone penetration tests with measurement of pore pressure (CPTu) in chalk. The CPTu's cone is a miniature driven pile and this technique permits the monitoring of degradation of sleeve friction and pore pressure development during cyclic loading. It was found that while consistent degradation of measured sleeve friction takes place within a few cycles, this was not associated with an observed pore pressure build up. However, uncertainties about the pore pressure measurements arose because the remoulded chalk next to the cone was probably unsaturated and also the pore pressure transducer was positioned close to the tip of the cone. Analysis of the results suggests that the technique may have promising potential to increase understanding of the underlying mechanisms and aid the design of axially loaded driven piles in chalk. Nevertheless further validation and development would be necessary in the future. © 2014 Thomas Telford Services Ltd. All rights reserved.
Banks D.,Holymoor Consultancy Ltd. |
Banks D.,University of Glasgow |
Withers J.G.,Geowarmth Heat Pumps Ltd. |
Cashmore G.,Kensa Engineering Ltd. |
Dimelow C.,Lankelma Ltd.
Quarterly Journal of Engineering Geology and Hydrogeology | Year: 2013
The results of 61 in situ UK thermal response tests, derived from three commercial test-rigs, have been analysed. Derived values of thermal conductivity yield a median of 2.25 W m K-1, with 25th and 75th percentiles of 1.86 and 3.0 W m K-1. The lowest single values are derived from Northern Irish basalt (1.1 W m K-1) and from Mesozoic and Tertiary argillites (often in the range 1.43-2 W m K-1), whereas the highest (<5 W m K-1) are from Sherwood Sandstone and Coal Measures strata where advective heat transport with groundwater flow may have led to an elevated apparent conductivity. Borehole thermal resistance exhibits 25th percentile, median and 75th percentile values of 0.09, 0.11 and 0.14 K m W-1 and correlates with borehole heat exchanger diameter and configuration. Undisturbed ground temperature exhibits 25th percentile, median and 75th percentile values of 11.7, 12.3 and 13.2 °C and exhibits a latitude dependence. © 2013 The Geological Society of London.