Smart Structures
Leads the Way
Bringing the technology of today and tomorrow to the driven pile industry
DBy Deb Draper uring the 10 years since its inception, Smart
Structures – based in West Palm Beach, Fla. – has
kept focus on developing smart sensor technology
to meet the structural data needs in civil infrastructure through
the development of sensors and related software products. Smart
Structures sensors, software and supporting hardware are protected
by nine patents in 32 countries and to date have been proven on
more than 100 bridges around the world.
Today, the company is a global leader in wireless Embedded
Data Collector (EDC) solutions used to determine pile capacity
and integrity in real time, improving the quality of deep foundations
while reducing overall foundation costs.
SmartPile® EDC technology is cast directly into any concrete
structural elements and then accessed wirelessly during curing,
transportation, installation and post-installation – i.e., the entire
lifecycle of the concrete structural element. A miniature batterypowered
electronic unit – the Dataport – is embedded into the
concrete along with one or more attached sensor packs that are
networked wirelessly and through patented and copyrighted software.
These sensor packs include combinations of accelerometers,
strain gauges, corrosion and temperature probes.
The SmartPile® components are designed to survive and work in
concrete from placement, through the curing process and during
and after heavy construction processes such as pile driving. Setup
and preparation time for pile driving is minimal as the SmartPile®
enabled devices arrive on site calibrated and ready for testing. Data
collected through the Dataport is transmitted wirelessly to a collection
and data processing station.
There are three variants of the SmartPile® Workstation, the most
compact and transportable can be hand carried by pile driving
inspectors and geotechnical engineers at the construction site for
activities such as pile driving, movement of prestressed beams or
other construction activities that require onsite inspection with
frequent repositioning. For longer term monitoring, a portable,
wireless, solar powered gateway can be used during the construction
process when it is necessary to frequently relocate the gateway.
After construction is complete, an unmanned, solar powered
gateway can be installed on or near the structure.
SmartPile® EDC technology provides real-time data on the
capacity and integrity of the structure as it is being constructed
and throughout its lifecycle. This translates into increased
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profitability for construction firms through an increase of resistance
factors (lower factors of safety), reduction of potential
for disasters from previously undetectable structural problems,
increased onsite safety for workers and increased contractor efficiency.
In addition, owners realize lower lifecycle inspection cost
through the analysis of pre-, during and post-extreme event data
and long-term data trends.
Is it cost effective and practically possible to test 100%
of the piles?
SmartPile® EDC technology is much more than a practical tool
for PDCA contractors to perform dynamic testing and estimate
pile capacity in real time on 100 percent of the piles. The system
provides engineers, contractors and owners real-time estimates of
tip and side resistances to be determined independently for each
pile using the embedded sensors at the top and the bottom of the
pile. Since there is no external gage attachment and detachment,
restrikes and redrives are performed faster, enabling the contractors
to obtain the true skin resistance and pile set-up without overdriving.
This process results in savings of time, material and labor
through reduced pile lengths and/or reduced number of piles, with
increased quality and enhanced safety.
When to do a restrike/redrive?
Presently, timing of the restrikes and redrives are dictated by the
engineer and can range from few hours to few weeks. Often, the
engineer’s decision is arbitrary because it is based on the individual’s
past experience, owner specifications and soil type at the
project site. Larger time intervals result in productivity losses to
pile driving contractors. Post driving, data from EDC pile bottom
strain sensors plotted with time is a good indicator when to perform
restrike. Therefore, the time period for when to restrike each
driven pile can be established based on measured data, enabling
the contractor to schedule the restrikes when they will provide
useful data while minimizing contractual issues in addition to
cost savings.
This technology was developed by Smart Structures out of a
commitment to the overall question of how to reduce uncertainties
in the design, construction and operations and maintenance
of infrastructure.