Abstract:
This presentation presents an approach to evaluate the in-place conditions for an auger cast-in-place (ACIP) foundation system of a halted construction project. The high-profile project involved numerous city agencies, and while halted became a community challenge as a stalled project. When Langan was engaged for this confidential project, the lead Agencies and Ownership were prepared to completely re-design the foundation; abandon over 500 installed piles; relocate the proposed building and start over. The questions regarding the installed foundation elements were primarily due to inconsistencies in the pile installation documentation. This presentation will discuss the approach taken to provide an alternative to abandoning the installed foundation and to lead the team through a process to understand “ what do we have that’ s good, ” and install nothing more or less than what was needed to provide a foundation system satisfactory to the Owner, regulatory Agencies, and the Designers.
We will present the methodology developed to document each installed pile, and the comparison of the automated grouting records to the field installation logs prepared by the controlled inspection agency. During Langan’ s involvement, we prepared design calculations and eventually created a full-scale proof-test and non-destructive testing program for the installed piles. We will elaborate on safety factors, and explore the philosophy that construction uncertainties are diminished once the respective foundation elements are installed. Ultimately, the project was able to move forward, with multiple stop work orders lifted, and only a limited number of replacement piles were required.