Pre-construction Phase Pile Foundation Constructability Review
The implementation of Load and Resistance Factor Design (LRFD) over the last several years by Federal and State Agencies has led to some challenges in pile design and specifying pile installation requirements as FTC has witnessed on numerous projects over the last few years. As a result, we have witnessed plan documents issued for construction that have had major issues such as incorrect geotechnical resistance factors for piling (this phi factor should be based upon the type of pile verification method to be used in accordance with the American Association of State Highway and Transportation Officials (AASHTO)).
Other issues have involved specifying a required pile capacity that is larger than the pile’s allowable structural capacity), selection of the wrong type or size of pile and inappropriate pile capacity verification methods.
To avoid such problems we recommend to our clients that they involve FTC as early as possible once they plan to perform a project involving pile installation. Given our extensive experience, often such issues can be resolved by performing a preliminary review of the project documents. In other cases WEAP (wave equation analysis) or PDA (dynamic pile testing) may need to be performed to ensure that the capacity and integrity requirements of the piling will be met. A better situation would be for owners and designers to engage FTC in performing such piling constructability reviews prior to issuing project documents for bidding.