Condition Assessment and Repair of Earthquake and Corrosion Damaged Pre-cast, Pre- Stressed Concrete Building Support Piles - A Case History

摘要

This case study describes the assessment and repair of pre-cast, pre-stressed concrete support piles used to support single story and two-story office buildings in northern California. This paper describes how it was determined during the assessment that the piles were damaged by an earthquake17 years prior to the assessment which resulted in cracks and high levels of chlorides penetrating the piles causing extensive damage to the embedded pre-stressed wires and vertical reinforcing rods in the piles to the extent that the piles required extensive repair. As a part of this project a classification system for evaluating the type and extent of damage to the piles was developed along with an appropriate repair procedure for each classification that would be effective in preventing additional corrosion damage to the piles for the remaining life of the subject buildings (approx. 30 years). Repairs consisted of a complete rebuild for some while others were coated with epoxy and still others were wrapped in a fiberglass sheets layered with epoxy.