Figure 4.15: Additional Drilled Displacement Piles
(a) Full Displacement Augers
Figure 4.5: Hydraulic Rig Drilling on M25 Motorway in England
Figure 4.10: Hardened Cutting Head
Figure 4.9: Cutter Heads for Hard Material (left) and Soil (right)
Figure 4.8: Auger for Use in Clay, with Auger Cleaner Attachment
Figure 4.7: Augers for Different Soil Conditions: Auger for CFA Piles in Sandy Soil (Top) and Augers for DD Piles (Bottom)
Figure 4.4: Low Headroom Rig with Segmental Augers
Design and Construction of Continuous Flight Auger Piles
Chapter 4 : Construction Techniques And Materials
This chapter provides details of the construction techniques, materials, and recommended practice for the construction of CFA piles for transportation projects. The guide specification included in Chapter 8 of this manual is a performance-based specification that allows the contractor to select the equipment, materials, and techniques to install a pile to provide the foundation capacity required for the job. This chapter is thus written with the performance-based specification in mind. Many types of equipment for installing CFA piles are presented, including some that are proprietary, which have been difficult to fit into the traditional design-bid-build project delivery method. Using a performance-based specification will allow for these systems to be considered more often because the contractor is bidding to provide the pile that meets the performance specifications at the least cost, regardless of pile type.
4.2 Construction Equipment
This chapter describes various types of drilling equipment used for the construction of CFA piles and DD piles, and provides details of tools, grouting/concrete equipment. Advantages and limitations of various types of drilling rigs are discussed, particularly with respect to torque capabilities.