Design & Analysis

Design of Piled Foundations and Earth Retention Structures

Ensuring constructability and cost effectiveness from the outset is critical to successful pile and retention system design. FSG directors and staff have direct industry experience in the design and installation of a comprehensive range of pile types, including bored and CFA piles, precast and steel driven piles, cast-in-situ displacement piles, as well as a broad range of ground improvement and retention systems. This practical experience, coupled with innovative and state-of-the-art analytical techniques and a realistic understanding of pile performance from FSGs extensive pile testing activities, provides invaluable input to our design and analytical processes.

Our blend of industry experience and high level analytical expertise is a significant asset to our clients. FSG is uniquely placed to develop optimal design solutions, in concert with consideration of key constructability and commercial factors that are critical to successful project delivery.

Driveability Analysis and Hammer Selection

FSG uses its significant dynamic testing database and practical experience in driven pile installation to develop drivability models which simulate realistic driving behaviour. Rather than adopting textbook input parameters that may bear no relevance to real pile driving behaviour, we are constantly refining our understanding of pile driveability in different geotechnical conditions though actual measurements of dynamic pile response. Our extensive PDA testing activities also provide an understanding of actual hammer performance, rather than simply relying on published specifications. These factors lead to a detailed understanding of the factors that affect pile driveabilty and hammer performance, and the associated risks and opportunities.

Design of Ground Improvement Elements

Ground improvement is an area of significant growth and innovation in the deep foundations industry. The knowledge and experience of our personnel in the design and construction of a broad range of ground improvement systems, including controlled modulus columns, soil mixing, stone and sand columns, dynamic compaction and replacement, jet grouting and others is a significant asset in developing design solutions for difficult ground conditions. Again, practical experience and commercial understanding is used in conjunction with the most advanced computer modelling software and analytical techniques to optimise both design and constructability outcomes.

Design Optimisation and Peer Review

FSG is regularly asked to provide specialist geotechnical support or peer review services with a view to enhancing both practicality and efficiency in design solutions. FSG has a strong track record of value engineering and risk mitigation and management input on a broad range of deep foundation and retention projects.

Earthworks Design, Specifications and Procedures

FSG has extensive capability in the specialist geotechnical discipline of earthworks. Burt Look has developed procedures (1990s) to determine equilibrium moisture conditions with control measures as upper characteristic values for compaction control and zoned embankments and the use of weighted plasticity index as a screening tool.  These procedures have been adopted by various Road Authority specifications. FSG have also introduced innovative testing to Queensland such as Light falling weight Deflectometer (LFWD) for subgrade assessment and quality control; used Dilatometer for assessment of slope failure surfaces and Time domain reflectometry (TDR) for moisture monitoring instrumentation was applied to roadways in the construction industry.

The earthworks processes involved in the design and construction of buried pipes are often poorly understood and implemented.  FSG had been involved in several legal cases on buried pipes and writing of specifications for Council.

Expansive Clays

The assessment and design of infrastructure on expansive soils is an area of specialist expertise.  Innovative design procedures such as Vertical moisture barriers for expansive clay moisture control were introduced to Queensland roads in the 1990s by Dr Burt Look. His PhD research was on “The Effect of Volumetrically Active Clay Embankments on Roadway Performance”.  The understanding and development of earthworks specifications flowed from these findings.

Landslide and Slope Stability Assessment

FSG have a number of staff members who are RMS certified site assessors for slope risk analysis, and have experience in the assessments and design of 100’s of slopes.  Innovations such as light weight fill (2012) for landslide stabilization and borehole shear testing (BST) have been used by Dr Burt Look. Burt was called upon to lead a team of engineers in the emergency works landslip repairs during a 3 month emergency phase following extensive 2011/2012 summer rainfalls for the Queensland Main Roads.

Geostudio Slope/W is the key software used by FSG for slope stability assessment.  This is often coupled with Seep/W and Sigma/W for analysis where seepage, and stress/deformation affects the design.