Morris-Shea has successfully installed Partial Displacement Piles (PDP’s) on numerous projects throughout the US and Caribbean. This pile system is a hybrid pile system with features of full displacement DeWaal cast in-situ pile, along with features of a non-displacement Continuous Flight Auger (CFA) pile.
PDPs are reinforced concrete piles constructed by means of special PDP tooling comprising a large thick-walled internal pipe with relatively shallow exterior flighting. Installation requires a fixed mast rig, high torque turntable, and crowd capability. Morris-Shea owns drill rigs capable of installing from 14″ through 24″ diameter Partial Displacement Piles and depths of up to 115 feet. Foundation support has been provided for chemical plants, pulp and paper facilities, steel mills, power plants, refineries, high-rise buildings and many other structures.
The inherent soil improvement process of PDP pile installation generates higher lateral capacities compared to conventional non-displacement cast in-situ piles. Due to the high power of PDP drill rigs, pile production can reach up to 50 piles per day depending on site access, pile sequencing and pile length. The PDP is a low noise, vibration-free system. This can be advantageous where deep foundation support is needed in sensitive areas where noise and vibration are unacceptable. In areas of sensitive soils, vibration for pile driving operations can cause settlement or cracking from vibrations. PDP’s eliminate all risk of such potential delays and claims as a result of these factors. Drill rig instrumentation of drill depth, torque, auger rotation and concrete volume facilitate a controlled drilling and concrete process and provide a record of each pile installed.
In summary, the main benefits of Partial Displacement Piles are:
- Increased unit shaft friction allows shorter or fewer piles to be used for the same loads as compared to drilled shafts, augercast piles or driven piles.
- Reduced volume of excavated soils over conventionally drilled piles such as drilled shafts and augercast piles.
- High production rate, results in schedule acceleration.