CPI-7 piles

CPI-7 are those piles that are drilled and concreted “in situ” where, due to the characteristics of the soil, no support system is necessary.

Execution

Excavation in soft and medium ground is completed using short propeller drills. In cases with harder ground, a tungsten carbide tipped drill is needed. In very hard, rocky ground a circular tungsten carbide tipped crown drill is used.

Once the desired depth is reached, the bottom of the excavation is cleaned using a scoop (‘bucket´).

Alter clearing the base a steel reinforcement is introduced with the help of additional equipment (a crane). To guarantee the minimum necessary coverage it is raised 20cm above the base of the excavation and separators are used for correct centring.

Alter placing the steel frame the concreting begins. To pour the concrete into the hole properly, avoiding segregation or bleeding, a tremie tube is used. The tube is fed through the steel frame until the base of the hole is reached. Then the concrete is pumped, which should be of a fluid consistency.

Whilst the concreting progresses, the tremie tube is simultaneously raised, taking care to always keep it two metres below the level of the fresh concrete. When the concrete reaches the surface level the concreting finishes. Finally, the tops of the piles are removed.