Correct and appropriate choice of technology is crucial with regard to drilled piles. Any additional costs, remediation or reconstruction can be avoided by successfully stabilizing and constructing the pile shaft.
Before starting the geotechnical projecting of the piles, it is necessary to obtain as much high-quality geologically-geomechanical data about the soils as possible. This information is obtained with field investigations, which must be performed according to the standard SIST EN 1997-2: 2007 - Eurocode 7: Geotechnical design - Part 2: Ground investigation and testing. Designing and constructing the piles is performed in accordance with SIST EN 1997-1: 2005 - Eurocode 7: Geotechnical design - Part 1: General rules.
During the process of pile installation, the wall of a borehole is stabilized with a casing pipe and/or using the slurry. The casing method has been in use for many years, while the use of slurries was introduced in the 1950s. Casing is used when there are incoherent soils or loose rocks, while the slurry protects the borehole’s walls in presence of softer clay layers. Both methods have advantages and disadvantages but are equally successful in practice.
In the first part of the thesis the types of foundations with an emphasis on deep foundations are defined and listed, which are followed by a presentation of key methods of field investigations. Furthermore, the methods and installation procedures of bored piles are described and succeeded by a demonstration of drilling machinery and equipment for successful and quality execution of the pile. In the last part the procedure of installing protective tubes and preparation and usage of the slurries is described.
|
