At CZM, we build drilling rigs for most types of special foundations. We have models designed for CFA and Displacement Piles for soils and loads where a single pass method can be applied. We also offer Cased CFA with a double rotary for the installation of secant walls and Jet Grouting and Soilmixing for soil improvement in the right conditions.
CFA (Continuous Flight Auger) is a single pass piling method, where a continuous flight auger is used to drill to depth. We offer machines in two different CFA Configurations. Our cylinder crowd models can be converted to Bottom Drive CFA, which is a patent system by CZM. Our Cable Crowd models can be converted to Top Drive CFA.
Displacement piles are a single pass method similar to CFA, but no soil spoils are removed. Instead of removing the soil while drilling, the tool is designed to push the soil, densifying it, and consequently increasing the skin friction of the pile.
The main application for drilling with a Cased CFA is to build Secant Walls using a single pass method. When the conditions are right many piles can build in a day, being more productive than doing secant walls with kelly bar drilling and segmented casing or diaphragm walls.
Jet Grouting is a soil improvement technique that consists of drilling to depth with a pipe and then injecting grout at a high pressure (up to 11,600 psi) that is then mixed with the soil creating a column. It can be performed around underground structures and is valuable to stabilize soils, seal underground, underpinning and excavation support.
Deep soil mixing is a process that can be executed for improving soil in determined conditions. The method consists of mixing self-hardening cement mixture with the soil on-site. The machine drill mixes the tool into the ground at the same time it injects a mixtures of cement. Once the desired depth has been reached, the tool can be extracted while the rotary continues the mixing process. The result of this process is a soil with improved load capacities.