Prediction of ultimate bored pile capacity using global strain extensometer

Abstract

Study was carried out generally to obtain the reliable range for Ultimate Skin Factor, Ksu and Ultimate End Bearing Factor, Kbu with the change in Standard Penetrtion Test (SPT, N) value. The analysis on the Ultimate Skin Friction Qsu and Ultimate End Bearing of the pile Qbu. Was carried out. After that, the back-analysis of the Ultimate Skin Factor, Ksu and Ultimate End Bearing Factor, Kbu done should able to conclude a better correlation comparative to SPT, N value obtained from soil investigation result. However, the Ultimate End Bearing Factor, Kbu has very little contribution to Ultimate End Bearing as far as the limiting settlement criteria are concerned. Pile instrumentation is to be done using state-of-the-art Global Strain Extensometer technology consists of a deformation monitoring system that uses advanced pneumatically anchored extensometers coupled with high-precision spring-loaded transducers, and a novel analytical technique to monitor loads and displacements down the shaft and at the toe of foundation piles. The technology enables installation of instrumentation after pile-driving and thus virtually eliminates the risk of instrument damage during pile production and installation. Vibrating wire strain gauges and mechanical tell tales are installed and the bored pile is concreted. It is basically a onetime usage instrument. Installed and casted properly, it will allow the monitoring of axial load and movement at various levels down the pile shaft. There are instances where the instruments were damaged during concreting. Human factors contribute to nearly all of the damages incurred. The global strain extensometer was then introduced. Upon load testing, the instrument will then be lowered into the tube of Sonic logging. This will ensure that the instrument would not be damaged and can be used repeatability. The empirical formula for unit skin friction and unit base resistance can also be established for the soil in Malaysia.