Piling and Ground Improvement Services in Florida

CFA piles are constructed by rotating a hollow stem continuous flight auger into the soil to a designed depth. Concrete or grout is pumped through the hollow stem, maintaining static head pressure, to fill the cylindrical cavity created as the auger is slowly removed. The reinforcement cage is placed through the freshly placed concrete.

Typically, CFA piles are reinforced with a rigid twenty feet long cage as a minimum, but it’s possible to install much longer cages as and when required by the design or specification. If required, a specially developed vibrator unit can help accurately locate the reinforcement cages.

• Resists compressive, uplift, and lateral loads
• A cost efficient foundation solution
• Can be installed in most soil conditions such as sands, clays, silts, gravels and soft rock
• Pile depths and diameters follow the project design, ground conditions and agreed installation scope.
• Low noise level and no vibration so ideal in built-up areas with weak soil conditions and high levels of ground water
• Compared to bored piles, construction is very quick as temporary casings or support systems are not required

Close control of the installation process is essential to ensure the highest quality pile construction.
Project installation records can include pile identification, depth, auger rotation, penetration rate, placement pressure, withdrawal rate, material volume, reinforcement and relevant incidents. The required monitoring and records are established for the agreed scope.
Controls and acceptance requirements are coordinated with the project team.
Quality assurance is achieved through a range of non-destructive testing methods to evaluate both pile integrity and/or load-settlement performance. Selection of verification technique is project and application specific.

Piles are generally installed using standard tracked or wheeled excavators with a torque motor attachment which monitors the torque achieved during installation for comparison with the project criteria.
Helical Piles are advanced to the predetermined (design) bearing strata by rotating the steel shafts with the torque motor attached to the excavator plant/rig. Multiple steel sections are connected via a bolted connection and sections are added to complete the total pile depth.
Helical flights strategically designed along the shaft penetrate the soil without augering, displacing the soil, while the torque is carefully monitored as the pile advances. The final torque reading is taken over the last 1m of advancement to ensure the pile is achieving the required design before terminating at the correct datum level.
Helical Piles are able to restrain unfactored (SWL) axial loads of up to 300kN, uplift loads of up to 200kN subject to the ground conditions and lateral loads of up to 25kN. Higher lateral forces can be restrained with the addition of a concrete collar to the top of the pile head.
A detailed understanding of the subsurface conditions (especially soil strata type, strata levels and strength (SPT ‘N’ Values) to depth is necessary to properly interpret the required design and torque capacities. On completion, the top of the pile can be connected in various ways to the structure by a direct steel flange plate connection or plate/rebar connection to concrete.

• Permanent or temporary applications
• Removable using the same equipment and method reducing environmental impact
• Reusable so a sustainable product
• Loading follows the approved system, connections and project acceptance requirements
• No spoil
• Can be installed in contaminated soils

Techno Piling is able call upon a wealth of knowledge and experience to offer and successfully deliver the optimum solution. Static load testing can be done to monitor and confirm performance and that the required settlement criteria is met.

A driving shoe is placed after preparation of the working platform and pre excavation of the footings. The steel pipe piles are about 5 feet long and formed with a shock sleeve. The first pipe is installed into the driving shoe and then one pipe after the other stuck together and driven down until driving criteria is reached.
If there are grouted piles to perform, the first pipe is cut close to the driving shoe so that the mortar is able to full fill the free space between the pipe and the soil performed by a larger diameter of the driving shoe. Diameters from 3” up to 12” are normal depending on the soil conditions
Directly after installing the piles, the pile heads designed as steel load spreading plates are placed on the steel pipe piles.

• Resists compressive, uplift/tension, and lateral loads
• Can be installed in restricted access and low headroom sites with minimal disruption to operations
• May avoid utility re-routing
• Alleviates quality assurance concerns associated with cast-in-place piling in weak soils
• Can be combined with other techniques to meet unique or complex project requirements cost-effectively and efficiently
• No spoil
• Can make the optimum pile length according to load and soil conditions

The load capacity of each pile can be controlled with driving criteria and the optimum pile length achieved. Driving observations support engineering review; capacity verification and load testing follow the specified project criteria. A static load test can give values of the pile load capacity.

In the wet top-feed process, the vibrator penetrates to the design depth using the vibrator’s weight and vibrations, as well as water jets located in the tip. The stone (crushed stone or recycled concrete) is then added at ground level to the space around the vibrator created by the jetting water. The stone falls through the space to the vibrator tip, and fills the void created as the vibrator is lifted a few inches. The vibrator is then lowered, densifying and displacing the underlying stone. This vibro replacement process is repeated in lifts until a dense stone column is constructed to the ground surface.
The dry bottom-feed process is similar, except that no water jets are used and the stone is fed to the vibrator tip through an attached feed pipe. Pre-drilling of dense strata may be required for the vibrator to penetrate to the design depth.
Vibro rigs can be fully instrumented with an on-board data acquisition system. Data from the system, such as amperage and lift rate, can then be recorded and displayed in real-time alongside specified target values on an in-cab monitor. This monitoring allows the operator to correct any deviations in real-time during the construction process to keep the vibro compaction within project specifications.

• A versatile ground-improvement method than can be adjusted to a wide variety of soil conditions and foundation requirements
• Offers an economical solution for ground improvement
• Treatment depth and spacing are established by the ground-improvement design
• Relatively quick execution so subsequent structural works can follow very quickly
• Soil improvement enables standard shallow footings which can lead to savings
• Environmentally-friendly as uses natural and in situ materials
• Noise and vibration constraints are assessed for the site and adjacent structures
• Only a small quantity soil has to be removed during the process so avoids the cost of spoil removal associated with continuous flight auger and bored piling systems

Installation records support review of the ground-improvement work. The required recording method, production parameters and acceptance criteria are agreed for the project.
A variety of production parameters are generally logged during execution including depth, current, pull down force, uplift/pull down sequence, time and date and element number.
Field trials, specified penetration tests and load tests can support verification of the treatment. The engineer defines the test program and acceptance criteria.